The invention provides a method for fabricating a superlattice semiconductor structure capable of achieving excellent interfacial properties and uniformity. For the superlattice semiconductor structure according to the invention, a substrate is mounted on a susceptor within a process chamber. First and second source gases are supplied simultaneously to two different areas on the susceptor within the chamber to form first and second source gas areas separate from each other. The susceptor is rotated to revolve the substrate through the first and second source gas areas.

1. Field of the Invention
The present invention relates to a method for fabricating a superlattice semiconductor structure using chemical vapor deposition. More particularly, the present invention relates to a method for fabricating a superlattice semiconductor structure capable of improving interfacial properties of a superlattice and attaining uniformity within and among substrates.
2. Description of the Related Art
With the recent drastic development in Light Emitting Diode (LED) or optoelectronic device using compound semiconductor such as AlGaInP, there is a rising demand for a superlattice semiconductor structure. For example, in fabricating group III-V semiconductor device, a buffer layer of the superlattice semiconductor structure can be formed between a substrate and a group III-V semiconductor layer, to solve problems caused by differences in lattice constant and thermal expansion coefficient between substrate material and group III-V compound semiconductor material. The superlattice semiconductor structure reportedly has advantages of inhibiting crystalline defects such as dislocation and improving electrical conductivity. Also, electron overflow can be prevented by forming an active layer of LED as a superlattice multiple quantum well structure. In addition, the superlattice semiconductor structure is greatly utilized in photonic crystal field. U.S. Pat. No. 6,706,585 discloses a method for fabricating layered superlattice materials via chemical vapor deposition. FIG. 1 is a schematic view of a compound semiconductor device with a general superlattice structure. Epitaxial layers 13, 14 of different compositions are stacked alternately and repeatedly on a substrate to form the superlattice structure. For example, the superlattice structure can be fabricated by stacking GaAs layer 13 and AlAs layer 14 alternately on the sapphire substrate 11.
However, to form the superlattice semiconductor structure requires regular and repeated growth of an ultrathin layer, which however renders it difficult to obtain uniformity and reproducibility of the superlattice structure in large-sized batch-type equipment. Further, interfacial properties of the superlattice structure are an influencing factor for properties of a total superlattice structure. But problems arising from fabrication process or fabrication equipment easily deteriorate interfacial properties of the superlattice structure.
FIG. 2 is a timing diagram for explaining a conventional method for fabricating a superlattice semiconductor structure. FIG. 3 is a schematic flow diagram of a metal-organic chemical vapor deposition (MOCVD) apparatus applied to a conventional fabrication method of FIG. 2. Conventionally, for example, to form the superlattice semiconductor structure of FIG. 1, an MOCVD process is utilized to supply different source gases alternately and repeatedly to a process chamber. Source gases are introduced into the reaction chamber to form and deposit the semiconductor layers.
Referring to the timing diagram of FIG. 2, "ON" indicates that corresponding source gas is being supplied to the process chamber (chamber mounted with a substrate), while "OFF" indicates that corresponding source gas is not being supplied to the chamber (supply stopped). A first source gas, for example, may be source gas for forming GaAs layer 13 (e.g. trimetil galum (TMG)), while a second source gas may be source gas for forming AlAs layer 14 (e.g. trimetil aluminium (TMA)) (refer to FIG. 1). As shown in FIG. 2, the first source gas (TMG) is supplied to the process chamber to form GaAs layer 13 on the substrate mounted within the process chamber. Thereafter, supply of the first source gas is halted, and the second source gas is supplied to the process chamber to form AlAs layer 14 on the GaAs layer 13. The superlattice semiconductor structure can be attained by repeating such one cycle process, as shown in FIG. 1.
Referring to a flow diagram of FIG. 3, a first source gas is continuously supplied by s first source gas supplier 41 through a gas controller 43 and then flows to a switching valve 49. At the same time, a second source gas is continuously supplied by a second source gas supplier 42 through a gas controller 44 and then flows to a switching valve 46. Each of the switching valves 49, 46 performs on/off operation. In the case of 'on' operation, corresponding source gas is supplied to a process chamber 70, whereas in the case of 'off' operation, corresponding source gas is exhausted into a vent. Each of the switching valves 49, 48 performs on/off operation alternately and thus only one of the first and second source gases is supplied through a nozzle 20 to a substrate 11 mounted on a susceptor or a susceptor 30. The susceptor 30 continues to be rotated during the process in order to revolve a plurality of substrates.
That is, as shown in FIGS. 2 and 3, while the first switching valve 49 is ON, the second switching valve 46 is OFF. Thus, only the first source gas (e.g. TMG) is supplied through a source gas introduction line 48 to the process chamber 70, while the second source gas (e.g. TMA) is exhausted into the vent 46a.
On the contrary, while the first switching valve 49 is OFF, the second switching valve 46 is ON. Consequently, only the second source gas is supplied to the process chamber 70, while the first source gas is exhausted into the vent 46a.
During supply of the first or second source gas, a third source gas (e.g, AsH3, source gas of As) may be supplied through the source gas introduction line 47 and the nozzle 20 to the process chamber 70. Residual gas after reaction in the chamber 70 is exhausted outside through an exhaustion line 61. Repetition of such operation allows fabrication of the superlattice semiconductor structures 13, 14 as shown in FIG. 1.
However, according the aforesaid method for fabricating the superlattice semiconductor structure, the switching valve is selectively switched, causing half of source gas to be exhausted into the vents 49a, 46a and thus unnecessarily increasing purchase price of source gas. Further, the switching valves are placed at a considerable distance from the process chamber so that it takes great time for a desired semiconductor layer to grow after switching of source gas. In addition, it takes substantial time before source gas is evenly spread to ensure uniform growth of the semiconductor layer in a batch-type process chamber. Such time requirement deteriorates interfacial properties of the superlattice, impairs uniformity within and among the substrates and leads to low reproducibility. Also, the aforesaid time requirement and difficult control of on/off operation prolongs process time and complicates process.

Method for fabricating superlattice semiconductor structure using chemical vapor deposition


An automatic soldering machine utilizing many design features which substantially reduces maintenance, simplifies the soldering operation, improves the process reliability, reduces the cycle time, and reduces the cost to fabricate such a machine.

1. Field of the Invention
The present invention relates to an automatic spot soldering machine, and more particularly to an automatic soldering machine used for high volume assembly operations of components such as PC boards, electrical terminals, and the like.
2. Description of Related Art
Many attempts to develop general-purpose automatic spot soldering equipment have been made in the past, but these attempts have not been entirely successful. This is evidenced by the large number of types of machines and methods presently used such as induction, laser, resistance, open flame, hot air, molten solder, infrared, electrical resistance, and hot iron systems. Each method of heating the soldered parts and melting the solder and flux have advantages and serious disadvantages which exclude any specific type of machine for usage on a wide variety of parts.
The most prevalent systems-consist of a metal tip that is heated to a pre-selected high temperature by any convenient heat source such as an electrical resistance element.
Solders that are predominantly used typically melt at about 400xc2x0 F. Non-corrosive fluxes activate at 400xc2x0 F. to 600xc2x0 F. and rapidly decompose at temperatures over 600xc2x0 F.
The most convenient method of providing the solder and flux is in the form of a solder wire containing a core of rosin flux.
Solvents used in fluxes vaporize at about 200xc2x0 F. and do so quite explosively at temperatures over 600xc2x0 F. This splatters flux and solder particles adjacent to the tip. The solder tip temperature for fast and good saturation of parts is usually desired to be over 800xc2x0 F.
In spite of good vacuum systems, the solder/flux sputter and condensation of the flux vapors collect on the mechanical components that are in close proximity to the solder tip. The condensed flux is tacky when warm and solid when cold. This adversely affects the motion of mechanical components.
At solder tip temperatures over 600xc2x0 F., the solder coating on the metal tip periodically becomes removed, which seriously reduces the heat conduction and possibly produces defective parts. Recoating the tip with solder requires tip cleaning motion with a cleaning pad, which interrupts a production line sequence.
A typical cycle sequence for soldering consists of: 1) lower the hot solder iron on top of the part(s); 2) feed the solder wire point against the side of the hot solder tip, at the interface of the tip and part; 3) dwell in this position until the part(s) are heated to over 400xc2x0 F., which allows the flux to react and the molten solder to saturate the part(s); and 4) remove the solder iron to the initial position.
Another typical sequence is to: 1) feed the solder wire out between the part(s) and solder tip; 2) lower the solder tip onto the solder wire; 3) melt the solder (and flux) and continue the tip motion to allow the tip to press against and heat the part(s); and 4) dwell and then release the solder iron.
The present invention is designed to provide a low cost, low maintenance, general-purpose machine, which also eliminates the problems involved with other systems.
The cycle sequence of the solder iron tip motion, tip temperatures, tip velocity, solder wire feed rates, and solder wire feed pressures are precisely controlled for each application with considerations including the part size, solder wire size, cycle speed, dwell time between parts, factory temperature variations, line voltage fluctuations, and material variations. These adjustments can only be optimized by an experienced person with access to proper tools and equipment.
One example according to the teachings of this invention provides a non-adjustable machine that is preset at the solder machine factory for a specific part.
A second example according to the teachings of this invention provides an automatic spot solder machine with adjustable controls limited to the solder wire feed length and cycle speed.
A third example according to the teachings of the present invention includes means to heat the tip from 500xc2x0 F. to 700xc2x0 F. within 0.75 seconds or less, including means to cool the tip from 700xc2x0 F. to 500xc2x0 F. within 1.5 seconds or less.
The rapid cooling and heating of the solder iron tip are required to maintain a reasonable high production rate, which also provide many variations of the basic cycle sequence. Also, the cool tip prevents the tip surface from oxiding and losing its solder coating when not in use. However, if some area of the tip loses its coating, a low temperature melting of the solder and flux allows the tip to become re-coated with solder. This eliminates the need for a tip xe2x80x9ccleaningxe2x80x9d cycle.
An exemplary cycle utilizing the teachings of the present invention can be: 1) the solder iron tip is normally at a temperature of 300xc2x0 F. to 500xc2x0 F. when idle; 2) feed the solder wire out to position the front section between the tip and part(s); 3) simultaneously lower the tip onto the solder wire and heat the tip to a temperature of 400xc2x0 F. to 600xc2x0 F.; 4) melt the solder wire and flux at this low temperature, which reduces or eliminates splatter of flux and solder; 5) increase the tip temperature to 600xc2x0 F. to 1200xc2x0 F., for a rapid saturation of solder into the part(s); and 6) return the tip to its original position and simultaneously allow the tip to cool to a temperature of 300xc2x0 F. to 500xc2x0 F. in time for the next cycle.
Another exemplary cycle utilizing the teachings of the present invention can be: 1) the solder iron tip is normally at a temperature of 300xc2x0 F. to 500xc2x0 F. when idle; 2) lower the tip onto the part(s) and simultaneously heat the tip to a temperature of 500xc2x0 F. to 700xc2x0 F.; 3) feed the solder wire/flux into a hole on the side of the solder tip, where a connecting hole on the bottom surface of the tip allows the molten solder and flux to exit the tip and onto the part(s) (see FIG. 3); 4) increase the tip temperature to 600xc2x0 F. to 1200xc2x0 F., for a rapid saturation of solder into the part(s); and 5) return the tip to its original position and simultaneously allow the tip to cool to a temperature of 300xc2x0 F. to 500xc2x0 F. in time for the next cycle.
A fourth example according to the teachings of the present invention includes a solder iron tip with a cross hole for feeding the solder wire into the hole. This allows the solder/flux to melt within the solder tip, which eliminates all splatter of flux and solder. Exiting the molten solder/flux through a hole at the bottom of the tip places the solder/flux exactly where the part(s) are located. (See FIG. 3).
The objectives in feeding the wire through the tip include: 1) prevent splatter of flux and solder; 2) deposit the solder/flux precisely; 3) reduce the decomposition of the flux by reducing the area and contact time of the flux on the hot solder tip, which also improves the solder saturation into the parts and assists in maintaining a coated solder tip; and 4) create a high-pressure extrusion of the molten solder/flux out of the solder tip, onto the part(s).
Many previous attempts by others and this inventor to provide a solder wire feed through a hole in the solder tip were unsuccessful. Large diameter solder/flux wire over 0.125 inches, which is seldom used in high production, is relatively easy to process by this method. Smaller diameters are possible only with a precise design and control of many inter-related variables.
These variables are: temperature of the solder tip; diameter and feed rate of the solder wire; diameter, length, and thermal conductivity of the solder tip; size and length of the entrance hole; cycle speed; and timing. It is desired to feed the solder wire through the hole without any blowback. The entrance hole may be larger or smaller than the solder wire diameter. If the hole is smaller than the wire, the wire may be pushed in with a high force and high speed, which shaves or melts the outside surface of the wire. If the tip temperature is hot enough, the wire surface can be melted at any reasonable speed. If the feed rate is too slow for any given temperature, the outside surface of the wire melts to a depth, which allows blowback (See FIG. 4).
If the diameter of the hole is larger than the wire diameter, which is the more practical method to control the other parameters, then the sealing of the space between the wire and hole wall is made by the solidification of molten solder. The liquid solder blows back into the space, which rapidly cools when in contact with the inwardly moving wire. This effectively increases the wire diameter to the dimension of the hole, leaving no space for a blowback (See FIG. 5). In this configuration, the length of the hole becomes a significant factor. If the length of the hole is very short, then the solder/flux blows out before it has a chance to cool, even if the hole clearance is very small. If the hole length is very long, then the hole size may be very much larger than the wire size, especially if the hole is a long tube with a cold (less than the melting temperature of the wire) entrance opening, in which case the feed rate may be fast or very slow (See FIG. 6).
In all configurations, the maximum feed speed is limited to the speed at which the wire point melts. The melting speed is a function of the wire diameter, length of the hole, tip temperature, feed pressure and the thermal conductivity between the hole and the wire surface.
Another design variation, which decreases the criticality of the temperature, feed rate, hole size, and length is to plate the hole wall with a non-solderable material such as chromium plating or ceramic. The non-solderable surface will substantially reduce the thermal conductivity. This requires a hole larger than the solder wire diameter. If the other design parameters are such that a slight blowback occurs, then the flux decomposes and the residue adheres to the wall of the hole, which reduces the diameter of the hole. Also, the non-solderable hole wall is a poor heat conductor. Therefore, the incoming cold solder wire quickly solidifies the outward moving solder/flux.
A fifth example according to the teachings of the present invention includes a solder wire feeder and an accurate wire guide mechanism. The solder wire is ductile with a low beam strength, cold flows, not always straight and free of kinks and quite often becomes coated with flux. Also, the guide and feeder mechanism require accommodation for heat and flux contamination. One disclosed example consists of a rigid guide rail, which is open on the top surface, in the form of a groove. The solder wire nests within the groove and is held down with a spring, which is positioned close to the end of the rail. The spring maintains a pressure against the wire, which keeps the wire straight and deflects whenever irregularities on the wire feed through (See FIG. 2).
To prevent buckling of the free end of the wire, between the end of the rigid rail and solder tip, the end of the rigid rail is positioned within 16 diameters of the solder tip. It is anticipated that this rail could extend up to the solder tip or, if fabricated out of a low heat conductive material such as ceramic, it could be an integral part of the solder tip (See FIG. 6). All disclosed designs require the feeder mechanism to be small to provide access of the solder tip to various parts which are soldered, be tolerant to contamination from flux and solder particles, and have a low inertia to minimize the forces required for a rapid feed and pull back of the wire. Also, the infeed of the solder wire is occasionally obstructed or encounters a hesitation. This requires that the feeder apply a forward force on the wire that is as high as possible but less than the buckling force of the wire.
The high solder wire feed force, combined with a good seal between the solder wire and the in-feed hole on the solder tip, creates a high out-flow pressure of the molten solder. The solder wire feeding into the hole acts like a piston.
The disclosed machine includes a cam actuated feed finger consisting of a lever with a small point which imbeds and engages the solder wire. The configuration of the point and the depth of penetration determine the forward force that is applied by the lever onto the wire. If an obstruction prevents the wire from feeding forward at the velocity of the feed finger, the point cuts a path in the top surface of the wire, which imparts a predetermined, maximum, constant forward force on the wire (See FIG. 2). The constant force on the wire is imparted to the wire at the point of engagement. Therefore, all feed mechanism inertia forces are eliminated. It is anticipated that other more complicated methods of applying a constant force are possible many with compromises on the basic requirements.
The disclosed machines provide a relatively constant force, and are relatively simple in construction, contamination tolerant, small profile, and low cost.
The feed finger is actuated by a cam motion, which provides a simple, high force, high velocity drive system for the feeder, which is always in exact timing with the tip motions.
The combination of the high force, high velocity, and close fitting guide rail causes the soft, gummy solder wire to gall (stick) within the guide groove. A very light coating of oil is required on the solder wire. Most solder wire manufacturers do not provide lubricated wire.
A sixth example according to the teachings of this invention includes an oil pouch having a rectangular piece of open cell neoprene, vacuum filled with oil, and sealed in a plastic bag, which provides a clean method of handling this item (See FIG. 1, reference number 17). It is installed into the machine system by piercing the solder wire through the plastic and foam. This item costs on the order of one dollar and replaces a previous oiler and wiper system that cost approximately one-thousand five-hundred dollars. A seventh example according to the teachings of the present invention includes a means to electrically heat the tip with a low voltage and amperage greater than 300 amps, at 10 to 100 Hz. The high amperage alternating current creates an electrical/magnetic field in the molten solder, tip, and parts, which vigorously vibrates the molten solder. This improves the saturation of the solder into the parts. The input power of 60 Hz AC is ideal for this function.
The high amperage AC also repels molten solder from the solder tip. Therefore, a short burst of high current at the instant when the tip is removed from the part repels most of the excess solder that normally adheres to the tip. This action eliminates a sharp residual point of solder (known as an icicle) from forming on the surface of the part. Another advantage of this repulsion effect is to eliminate any splash of solder balls during the tip retraction. When the tip separates from the part, the molten solder strings out into a bridge between the tip and part. When the string breaks, a section of the string sometimes breaks away into a small ball and flings out. The repulsion effect of the solder tip eliminates any bridging effects.
An eighth example according to the teachings of the present invention includes a solder cycle wherein a short pulse of alternating current is applied to the solder tip simultaneously with the upward motion of the solder tip.
A ninth example according to the teachings of this invention consists of a solder tip holder, which is required to be moveable, stiff, precision, and tolerant to contamination. These requirements are provided for by placing the solder tip holder on a support bracket, which is then pivot mounted on pre-loaded ball bearings. The pivot bearings are located at some distance away from the solder tip (See FIG. 1, reference number 14).
A tenth example according to the teachings of the present invention includes a cam drive, which powers substantially all of the mechanical motions (See FIG. 1, reference number 12).


Forming dies adaptable to conventional tube bending machinery, the forming dies including aligned forming rollers engaging the tubing to be bent, said forming rollers containing grooves having curvilinear surfaces said forming rollers initially deforming the said tubing into a first curvilinear shape upon the drawing or pushing of the tubing between the forming rollers. A bend die is aligned with a pressure die roller, the pressure die roller and bend die each containing grooves having curvilinear surfaces defining a second curvilinear shape. Upon drawing or pushing the tubing through the pressure die roller and bend die, a second curvilinear shape is imparted to the tube. The tubing may thus be provided with an enhanced curvilinear shape prior to bending.

1. Field of the Invention
This invention relates generally to an apparatus and method for bending of tubing and more particularly to an apparatus and method for preforming of tubing to a desired curvilinear shape to provide for improved quality of tube bend.
2. Description of the Prior Art
Current rotary draw bending of tubes and pipes (pipe will be deemed included herein in references to tube or tubing) contemplates three sets of tools commonly used to form a tube bend. The tools are (i) a rotary bending form, also called a bend die, (ii) a clamp die, and (iii) a pressure die, sometimes referred to as a follower die. In current rotary draw bending practice the tube to be bent is secured between the bend die and the clamp die and aligned against the pressure die. As the bend die rotates, the clamp die rotates with it, the tube being formed in the arc defined by the bend die. The pressure die prevents the trailing portion of the tube from radial movement. The pressure die may remain fixed or it may move forward with the tube to eliminate sliding contact. The pressure die may also include rollers to eliminate sliding contact between the tube and the pressure die.
The quality of the resultant bent tube is determined by the amount of flattening on the outside of the bend, the amount of wall thinning on the outside of the bend, and the existence and degree of wrinkling or buckling on the inside of the bend.
To improve the quality of the bend, a mandrel may be placed on the inside of the tube to support it from flattening and to help prevent wrinkles from forming. Mandrel support of the tube requires use of lubricants to reduce drag, additional tooling to be set and adjusted, cleaning after bending, machine length limitations, and extra time in loading.
Another practice used to improve bend quality is to use multi-radius or parabolic-shaped grooves in each of the pressure die and bend die to contort the tube into a generally elliptical shape during bending. A generally elliptical-shaped tube is more resistant to flattening and wrinkling of the tube during bending. This method allows bends to be made without a mandrel within certain ranges of relationships of outside diameter, wall thickness, and bend centerline radius. The relationship of tube outside diameter to bend centerline radius (CLR) is called the "D" of bend. A 2" O.D. tube bent on a 4" CLR would be a 2.times.D bend (CLR/O.D.). The smaller the "D" of bend, the greater the wall thickness must be to support the tube during bending to maintain ovality quality requirements. As the wall thickness increases it becomes more difficult to contort the tube into a parabolic shape. As currently practiced, generation of a parabolic shape in the tube requires a relatively high level of pressure die clamping force and may result in deformation of the tube at the entrance to the bend die. An additional die, commonly referred to as a wiper die, may be placed at the inlet to the bend die to overcome the deformation problem. However, the wiper die increases the friction load on the tube and in turn increases susceptibility to buckling or wrinkling.
Rotary draw bending may be accomplished by powered machinery with simple manual controls or operable by computer numerical control (CNC) systems. Such CNC systems include mechanical, electrical and/or hydraulic apparatus for positioning, clamping and rotating the bend die and further include mechanical and hydraulic apparatus for linear propulsion and rotation of the tube.
Machinery and apparatus reflecting the current state of the art of rotary draw bending of tubes is reflected in the following commercial publications:
Tube and Profile Cold Bending Machines (catalog), Schwarze-Wirtz K. G., Cologne, W. Germany. PA0 Computer Controlled Tube Bending and Tube Forming (catalog), Eagle Precision Technologies, Inc., Ontario, Canada. PA0 Miic CNC Pipe Bender (catalog), Chuo Electric Mfg. Co., Ltd. and Tube Tech, Inc., Taylors, S.C. PA0 Teledyne Pines (catalog), Teledyne, Aurora, Ill. PA0 Conrac Bending Equipment for Tube and Pipe (catalog), Conrac Machine Tool Division, Westminster, Calif. PA0 Tools for Bending, Inc. (catalog), Tools for Bending, Inc., Denver, Colo. PA0 CNC Bender (catalog), Chiyoda U.S.A., Goodlettsville, Tenn.
Stange, et al. U.S. Pat. No. 4,765,168 discloses a tube bending apparatus in which a tube is clamped between a u-shaped bend die and a cooperating pressure die. The pressure die advances in a linear direction as the bend die is rotated. The tube groove supplied in the pressure die and bend die have cross-sectional radii of curvature corresponding to that of the tube to be bent. The radius of curvature at the interior of the tube groove at the bend section is less than the outside radius of the tube to be bent. The radii of curvature of the sides of the groove tube have a cross-sectional radius of curvature greater than the outside radius of the tube to be bent with the side surfaces undergoing a smooth, gradual transition into the bottom surface. The bend die and linear pressure die disclosed in Stange allow the tube to assume an elliptical shape during bending.
Hamlin U.S. Pat. No. 3,242,710 teaches the use of a clamp die clamped to the tube to be bent, such clamp die progressing the tube to be bent tangentially in the direction of the bending form. In addition to the clamp die disclosed, Hamlin discloses one or more rollers disposed along the tubular stock exterior of the bend, one roller being advanced during the bending process to a location tangential to the bend die.
Robinson U.S. Pat. No. 1,510,162 describes a pipe bending machine having a pair of rotating bending rollers, each roller having concave grooves which correspond to the general shape of the tube to be bent. The tube to be bent is filled with sand prior to bending in the preferred embodiment in order to prevent collapsing of the tube.
Newhall U.S. Pat. No. 2,996,100 discloses a method for restricting the thinning of the tube metal in the outer wall during bending by applying against the outer face of the outer wall a temporary metal section of greater tensile strength than the metal of the pipe. The temporary metal section is bent with the tube.
Robinson U.S. Pat. No. 1,510,162 discloses a pipe bending machine having one or more rollers containing concave grooves contained between plates with a bending block for bending the tube.
Myer, et al. U.S. Pat. No. 3,456,482 describes a mandrel to be placed in a tube, said mandrel including a relatively rigid support member and a wear-resistant member, the wear-resistant member being constructed of plastics, ceramics, or carbides and having an external surface coated with lubricant.
Rothanburger U.S. Pat. No. 4,355,528 discloses a manually operated device for bending metal tube including a short cylindrical segment, a pivotal lever, and a pressing block mounted on the lever. The cylindrical segment has an exterior circumferential groove which determines the bending radius of the tube to be bent.
Kowal U.S. Pat. No. 4,380,922 discloses a manually operated tube bender comprised of a stationary bend die, a forming member which rotates about the bending axis, a lever attached to the stationary bend die, a lever attached to the forming member, a scale on the stationary bend die, and an indicator on the rotating forming member. Movement of the forming member about the bending axis is affected by manipulation of the levers.
Peppers U.S. Pat. No. 4,424,699 discloses a tube bender for manual operation. The tube bender includes a mandrel having a bending groove, a forming member mounted to the mandrel to swing about a bending axis of the bending groove, movement of the forming member about the bending axis is effected by manipulation of a pair of handles.
The current technology as disclosed in the commercial publications and the referenced patents indicate the desirability of providing an elliptical shape in the tube to be bent to reduce thinning in the outer surface of the tube to be bent and to reduce wrinkling along the inner surface.


The present invention provides a process for forming a semiconductor film, comprising the steps of applying a semiconductor particle dispersion liquid to a substrate surface by spray coating in such a manner that the atomized droplets of the dispersion liquid discharged from the spray coater have a mean diameter of about 30 μm or less, and drying the coating to form a porous semiconductor film; and use of the semiconductor film obtained by the process.

Semiconductors such as titanium oxide, due to their photocatalytic activity, have antibacterial properties, hydrophilicity, stain resistance, anti-fogging properties, gas decomposing properties, deodorizing properties, water-treating capabilities, energy conversion properties and other properties, and thus are used in a variety of fields.
In particular, photoelectric conversion devices, such as solar cells, that utilize the energy conversion properties of titanium oxide and other semiconductors are attracting attention as a means for producing electrical energy without adverse effects on the global environment.
When using titanium oxide or other semiconductors as photocatalysts, it is preferable to form them into porous films on substrates.
With regard to processes for forming a porous film of semiconductor, such as titanium oxide, Japanese Unexamined Patent Publication No. 1998-212120 discloses a process for forming a porous titanium oxide film, comprising applying a dispersion of titanium oxide particles in a glyme solvent, onto a glass, metal, ceramic or like substrate by spray coating, dip coating or like process, and then baking the coating at 200 to 800° C.
Further, Japanese Unexamined Patent Publication No. 2002-145615 discloses a process for forming a porous titanium oxide film on a substrate, comprising intermittently spraying a starting solution obtained by adding hydrogen peroxide or aluminum acetylacetonate to a titanium oxide precursor, onto a substrate such as glass maintained at a high temperature of 350° C. or 500° C. so as to thermally decompose the titanium oxide precursor to titanium oxide.
However, these processes have a drawback in that they involve heating at a high temperature of 200° C. or more to form a porous titanium oxide film, and therefore are not applicable to thermoplastic resin substrates that deform or degrade at temperatures of 200° C. or higher.
Japanese Unexamined Patent Publication No. 1999-204152 discloses a process comprising applying a dispersion of metal oxide particles in a high polymer material solution to a high polymer film provided with a conductive layer, and drying the dispersion at a temperature of 200° C. or lower.
This process employs a relatively low heating temperature, and thus is capable of forming a titanium oxide film on thermoplastic resin substrates. In this process, however, since the metal oxide particles are dispersed in a high polymer material solution, the obtained titanium oxide film has good adhesion but is unlikely to be porous. Thus, the process has a drawback in that the resulting film has inferior energy conversion properties, such as photoelectric conversion efficiency.

Method for forming semiconductor film and use of semiconductor film


A tail light assembly for a motorcycle includes a first array of at least one LED in illuminated in at least a first color. The first group of LEDs operates in a non-operating condition, a running condition where each LED of the first array is illuminated at first intensity, and a braking condition where each LED is illuminated at a second, brighter intensity. A second array of at least one LED is illuminated in at least a second color. The second array operates in a non-operating condition, and a flashing condition where each LED of the second array alternates between being illuminated and not illuminated. Each LED of the first array is illuminated at the first or the second intensity while each LED of the second array alternates between being illuminated and not illuminated in the flashing condition.

The present invention relates to tail lights on a vehicle. More specifically, it relates to a tail light arrangement on a motorcycle.
In the past, a motorcycle tail light arrangement commonly included three separate lamps. Two orange or amber colored turn signal lamps were provided, such that one was positioned on the left and the other was positioned on the right of a motorcycle. A middle red-colored lamp was provided to be illuminated while the motorcycle was running and illuminated at a brighter intensity when the brake was applied. Another arrangement used only two lamps, one positioned on each side of the motorcycle. Bi-colored LEDs were used, such that when the brake was applied, the LEDs lit up red and when the turn signal was used, the LEDs on the appropriate side blinked amber or orange. Because the LEDs were bi-colored, only one color, and thus, function, could be illuminated at a given time.

Harley-Davidson Motor Company Group, Inc.


The present application discloses a method to optimize operation of a transformer cooling system, the corresponding cooling system, and a method to determine the capacity of Variable Frequency Drives (VFD) that are used in the transformer cooling system. The method comprises: preprocessing the initial data input by user; collecting the on-line data, and calculating the optimized control command to meet the requirement of the transformer loss, top-oil temperature variation and noise; and executing the control actions by controlling a controllable switch and/or sending a control command to a VFD. Compared with the existing prior arts, the proposed solutions are much more intuitive and practical in the field of the cooling system.

Transformer is one of the most critical components of a substation, whose safety, reliability and efficiency are of high importance to the overall power grid. For each transformer, especially power transformers with voltage level 110 kV and above, a dedicated cooling system consisting of multiple motor-fan units is required to keep the winding temperature within an acceptable range. The operation of the transformer is therefore closely related to 1) how the cooling system is designed and 2) how the cooling system is operated.
As to the cooling system design, it is common understanding that variable speed operation of these cooling fans can achieve higher efficiency compared with fixed speed operation. Therefore transformer cooling systems tend to install VFDs for motor-fan units to ensure high efficiency operation, the system architectures are shown in FIG. 1A and FIG. 1B. However, these two types of architecture have their own disadvantages. The first architecture as shown in FIG. 1A requires high capital investment because it installs VFD for each motor-fan chain; plus if the motor-fan chain is mostly working at rated speed, VFD solution might lower the efficiency due to its own power losses. The second architecture as shown in FIG. 1B can relatively reduce the capital investment because it uses one big VFD to drive a plurality of motor-fan chains jointly at the same operation point. But the disadvantages are also obvious: Firstly, each motor-fan chain has low efficiency when the VFD utilized capacity is relatively low; secondly, there are different ways for load distribution among different VFD-fed motor-fan chains to meet the same total output requirement. It is not always true to distribute the load evenly among individual chains in order to have optimal system efficiency.
As to cooling system operation, the core is how to control the winding temperature. Normally, lower winding temperature leads to the lower copper loss of winding. However, the power consumption of the cooling system will be higher at the same time, meaning that the overall efficiency, considering both transformer winding and the cooling system itself, might be less optimal.
Besides efficiency, the variation of the winding temperature is also one key factor which will affect the lifecycle of the transformer. The more frequency the temperature varies, the faster the transformer aging will be. It could be so that the efficiency of the transformer is optimized, however at a cost of shortened transformer lifetime.
For transformer operated at urban area, noise level is also one important criterion to consider in order to reduce the impact on the neighbouring residents especially at night. Currently, few solution is available to control the cooling system to tackle the noise problem.
To overcome above shortcomings, the person skilled in the art aims to solve two problems as follows.
1) How to design the cooling system to realize speed regulation for the motor-fan loads selectively with less capital investment on VFDs.
2) How to improve the operation efficiency of transformer by cooling control considering the transformer copper loss, the motor-fans power consumption and the speed regulation of VFD.
3) How to control the winding temperature as well as its variation in order to extend the lifecycle of the transformer and meanwhile achieve the best overall system efficiency.
4) How to operate the cooling system to optimize not only the efficiency and lifecycle, but also minimize the noise level so as to reduce the negative impact on the surrounding environment.

Method to optimize operation of a transformer cooling system, the corresponding system and a method to determine the VFD capacity


A method for producing a serialized bundle of thermoplastic T-shirt grocery bags which serially open upon being dispensed. Specifically, a bag being removed from the serialized bundle of thermoplastic T-shirt grocery bags mounted on a dispensing rack automatically opens an immediately following and trailing bag. The bags of the serialized bundle are coextruded to have at least two layers, an inside layer having a low coefficient of friction and an outside layer having a high coefficient of friction. A relatively low coefficient of friction between two inside layers allows each bag to easily open; a relatively high coefficient of friction between the outside layers allows a leading bag to entrain a trailing bag. Entraining structures are provided into and between the respective bags which permit the bags to be keyed together at their high friction outside layers and separate at their low friction inside layers. These entraining structures may preferably include special flaps which overlie one another on a dispensing rod. A tab constraining each front wall to a wicket is either pre-severed or slit during the cut out operation to easily detach from the wicket so as to not overcome a self opening force which prevents the bags from opening automatically.

This invention relates to bags. More specifically, this invention relates to an apparatus and process for manufacturing a dispensing unit of co-extruded thermoplastic T-shirt bags. In the dispensing unit of bags, a series of bags overlie one another and are interconnected for serial dispensing. When a first front bag is packed with groceries and removed from a rack containing the remainder of the dispensing unit of bags, an immediately subsequent second bag is automatically opened in preparation for loading in its own turn.

Serial dispensing bags which open automatically


Methods and compositions for improving the strength and longevity of secondary roadways through environmentally sound practices are disclosed herein. A composition for road sealing includes an aqueous emulsion of acrylic and vinyl acetate polymer, water, and a resin-modified emulsion, wherein the resin-modified emulsion includes a mixture of pitch and rosin, an emulsifying agent, and water.

A. Field
This invention generally relates to methods and compositions for improving the strength and longevity of secondary roadways through environmentally sound practices.
B. Description of the Related Art
The engineering and construction of secondary roads (hereafter, "gravel roads," "earth roads," or "unpaved roads") has been perpetually plagued by two interrelated problems: the deterioration of the road due to water, and the loss of surface cohesion and road compaction due to traffic. The deleterious effects of water on roadways, in particular, are well documented in the prior art. In cold weather, moisture that penetrates a road's base layers freezes and rips cracks into the road substrate that seriously undermine the load bearing capacity and longevity of the roadway. Likewise, in milder weather, when water seeps into the road's base layers it results in softening and erosion that causes potholes that are an expensive and recurring problem. And if the potholes are not immediately repaired, they fill with water and further exacerbate the deterioration of the roadway.
The impact of water on secondary roads—such as rural roads, access roads, field and forestry roads, or mountain roads—is especially pronounced because the quality of the surfacing materials is lower than in an asphalt paved road, for example, and thus provides reduced surface protection from the elements. Additionally, because of capillary action, water also seeps into the road base from the sides and bottom of the road's base or sub-base. Compared to sealed or "paved" roads, which require large machinery to pour concrete or to lay and smooth a bitumen-based surface, secondary unpaved roads are relatively easy and inexpensive to build. But unpaved roads require much more frequent maintenance—particularly after wet periods or when faced with increased traffic—and are generally prone to other problems not associated with paved roads.
For example, many secondary roads of either an earth or gravel variety—utilize native soils, often in conjunction with gravel quarried from local resources, to create the road's sub-base and base layers. Unfortunately, native soils and gravel are not always of suitable quality, resulting in a road base with diminished physical and mechanical properties. When secondary roads are constructed of poor road base materials, routine maintenance is not strictly employed, and the road is exposed to heavy moisture and/or traffic, the erosion of the road—due to damage to the road surface, sub-base, and base materials—is hastened.
Defects in road surfaces are typically classified into two categories: surface deterioration and surface deformation. While surface deterioration is related mostly to the quality of the surfacing materials and the way they respond to weather or traffic stresses, surface deformations often have combined causes that include both stresses to the road surface itself and other factors such as sub-base and base capacity and stability. Surface deterioration is exemplified by "dust," the result of loss of fine binder material from road surfaces. Dust is a substantial problem for secondary roads, as the loss of these fine materials leads to other types of road distress such as loss of cohesion and compaction of the road fill material, and reduced capacity to maintain the requisite moisture in the road fill.
Surface deformations include ruts, corrugations, depressions, and potholes. Ruts are longitudinal depressions in the wheel paths caused by high moisture content, inadequate strength in the subsurface soil or base, inadequate surface course thickness, or heavy traffic loads. Corrugating or "washboarding" is a series of ridges and depressions across the road surface caused by lack of surface cohesion. Depressions are localized low areas one or more inches below the surrounding road surfaces that are caused by settlement, excessive moisture content, and/or improper drainage. Potholes are small depressions or voids in the road surface one or more inches deep which are caused by excessive moisture content, poor drainage, weak sub-base or base, poorly graded aggregate, or a combination of these factors.
As such, the problems typically associated with secondary roads—both surface deterioration and deformation—are caused by: 1) the harmful effects of water and high moisture content, including settlement and erosion, on the road surface and base, 2) the lack of surface cohesion and resulting loss of road compaction caused by dust, and 3) the heavy traffic loads exerted on roads with weak or inadequate soil, sub-base, or base. Industry has provided for the addition of various chemical additives to impart water repellency on road materials, with varying degrees of success and environmental impact. However, water repellant chemicals are not binders, and load bearing capacity, stability, and frost resistance are not improved by their application to the soil or road base. In many cases, dust can also be reduced on gravel roads by applying chemical additives commonly known in the art as "dust suppressors" or "dust retardants") which draw moisture from the air to improve fine aggregate cohesion. And "soil stabilizers," which are chemicals designed to act as binders and coalesce forming bonds between the soil or aggregate particles, have shown promise in greatly improving the load bearing and traffic capacity of the road. But existing soil stabilizers and dust retardants are difficult to apply and use in cold climates, tend to have long cure times, short life-cycles, and do not provide the requisite protection against water damage; particularly excessive moisture content resulting from capillary action.
Repairing damaged roadways by conventional methods can be extremely expensive, time consuming, and environmentally disruptive because the entire compacted gravel layer of the road must be replaced. Excavating the roadbed of a 1-km portion of road measuring 4 m in width produces about 2000 cubic meters (m3) of earthy waste; in a conventional road bed repair project, this would require roughly 220 truckloads of waste to be removed from the worksite, with 220 truckloads of new gravel being shipped back the worksite to complete the project. In isolated locations, or locations with difficult terrain, the expense of removing and later replacing the gravel is exorbitant as is the impact on local residents (who must cope with noise and air pollution), normal users of the roadway (who experience detours or extended delays during repair), and the landfills that store the removed waste. Conventional binders are a liquid asphalt, which turns into a black heat-absorbing road surface. At installation a conventional chip sealed surface must be swept resulting in the loss of as much as 20% of the chips installed.
As a result, there is a need in the art for an improved method of building up roads to create strength and longevity, wherein road builders will be able improve the longevity of the roadway, impart increased load bearing and traffic capacity, and reduce the time, costs, and environmental impact associated with conventional road repair projects.

Method and composition for road construction and surfacing


An object of the present invention is to provide an oligonucleotide useful as a therapeutic agent for dyslipidemia that has excellent binding affinity to the PCSK9 gene as well as stability and safety. The oligonucleotide of the present invention contains a sugar-modified nucleoside, the sugar-modified nucleoside has a bridging structure between 4′-position and 2′-position, and the oligonucleotide can bind to the human PCSK9 gene. Also, the present invention provides a therapeutic agent for dyslipidemia containing the oligonucleotide as an active ingredient, and the therapeutic agent preferably contains a bioabsorbable material as a carrier. The bioabsorbable material is preferably atelocollagen or peptide gel.

Familial hypercholesterolemia resulting from mutations in the LDL receptor gene is a disease that appears 1 out of 500 people (250000 people domestically), and is the most common disease among the hereditary metabolic disorders. Patients' serum total cholesterol levels show 230 to 500 mg/dL (healthy person: 200 mg/dl or less), and symptoms such as xanthoma of the skin and tendon and coronary artery disease resulting from juvenile arteriosclerosis are observed. The average life expectancy of the patients is 54 years for male and 69 years for female, being much shorter than the average life expectancy of the entire population. A typical therapeutic method may be LDL apheresis treatment, but this therapeutic method is problematic in that the method imposes a large burden on the patient. An example of drug therapy may be administration of statins, but there is a problem in that statins do not show sufficient effects on familial hypercholesterolemia.
Meanwhile, hyperlipidemia is a lifestyle-induced disease that causes cardiac infarction and apoplexy, which are causes of death next to cancer.
In therapeutic development for such hypercholesterolemia, a strategy targeting PCSK9, which regulates the metabolism of an LDL (low-density lipoprotein) receptor, has recently been attracting attention (Non Patent Literature 1). It aims at lowering the blood LDL concentration by suppressing the expression of the PCSK9 gene, which decomposes the LDL receptor, and thus increasing the level of LDL receptor expression and facilitating the cellular uptake and metabolism of LDL. Therapeutic experiments using an antisense method that is one technique involving nucleic acid medicines are also in progress.
Most of the conventional nucleic acid medicines that are effective in the in vitro cellular system are, however, not effective in vivo. Possible causes may be that conventional nucleic acid medicines are immediately decomposed when introduced into the body and that the affinity and specificity of conventional nucleic acid medicines to the target gene are poor, and therefore an antisense technique has been attracting attention as a technique to suppress the PCSK9 gene expression.
The 2′-MOE (2′-O-methoxyethyl)-modified oligonucleotide described in Non Patent Literature 2 has excellent stability in the living body but has a poor binding affinity to the target RNA, and is thus problematic in that a very high dose is required to demonstrate a pharmaceutical effect. The oligonucleotide containing a locked nucleic acid (LNA) described in Non Patent Literature 1 has a superior binding affinity to the target RNA, and an effect of suppressing the mRNA of PCSK9 in vivo also is shown, but there is still room for improvement in stability, safety, and the like in the living body.

Oligonucleotide, and therapeutic agent for dyslipidemia containing oligonucleotide as active ingredient

National Cerebral and Cardiovascular Center

Tokyo University of Science Education Foundation Administrative Organization


A vehicle alternator and methods for controlling an amount of torque loading of the vehicle alternator on an engine are provided. The vehicle alternator utilizes a voltage regulator with a microprocessor to control an amount of torque loading, based on a rotational speed of a rotor of the alternator, or an amount of current output by the alternator, or both.

An engine control module has been described there controls operation of an alternator to control torque loading on engine. A problem associated with this configuration is that when communication is interrupted between the engine control module and the alternator, the alternator may not be able to control torque loading on the engine.
Accordingly, the inventors herein have recognized a need for an improved alternator and methods for controlling the alternator that minimizes the above mentioned deficiencies.

Vehicle alternator and methods for controlling torque loading of the vehicle alternator on an engine


A complementary metal oxide semiconductor (CMOS) device having silicide contacts that are self-aligned to deep junction edges formed within a surface of a semiconductor substrate as well as a method of manufacturing the same are disclosed. Specifically, the CMOS device includes a plurality of patterned gate stack regions formed on a surface of a semiconductor substrate. Each plurality of patterned gate stack regions includes an L-shaped nitride spacer formed on exposed vertical sidewalls thereof, the L-shaped nitride spacer having a vertical element and a horizontal element, wherein the horizontal element is formed on a portion of the substrate that abuts each patterned gate stack region. Silicide contacts are located on other portions of the semiconductor substrate between adjacent patterned gate stack regions not containing the horizontal element of the L-shaped nitride spacer.

1. Field of the Invention
The present invention relates to complementary metal oxide semiconductor (CMOS) devices, and more particularly to a process and structure for forming a metal oxide semiconductor field effect transistor (MOSFET), wherein gate sidewall composite spacers, which are partially removed during device processing, are employed. The present invention thus provides a method to form low temperature silicide contacts that are self-aligned to the deep junction edges present in the device, while still achieving the lower thermal budget of a conventional disposable spacer process.
2. Background of the Invention
As CMOS technology becomes smaller and smaller, e.g., less than about 50 nm gate length, it becomes more and more difficult to improve the short channel device performance and at the same time maintain acceptable values for off-state leakage current.
One technique for achieving this is a halo technique wherein extra dopant implant regions are formed next to the source/drain extension regions. For this prior art method to work, the junctions must be abrupt, see xe2x80x9cCMOS Devices below 0.1 nm: How High Will Performance Go?xe2x80x9d by Y. Taur, et al., pp. 1-4. In particular, for sub-50 nm devices, not only the extension regions near the channel must be abrupt, i.e., less than 4 nm/decade, but the halo profile in proximity to the extension junction must be abrupt, i.e., less than 20 nm/decade.
In the prior art, halo formation is typically carried out by a general approach wherein the halo dopants are implanted at an angle ranging from 0xc2x0 to about 70xc2x0 into the channel region. This prior art approach varies either the dose, the type of halo dopant or angle of halo implants for improving device performance.
In the article entitled xe2x80x9cHalo Doping Effects in Submicron DI-LDD Device Designxe2x80x9d by Christopher Codella, et al., pp. 230-233, there is described the optimum halo doses for improving the threshold voltage Vt and the punch-through device characteristics. Punch-through stoppers were also discussed in U.S. Pat. No. 5,320,974 to Hori, et al., which is similar to the conventional halo arrangements.
The article entitled xe2x80x9cA 0.1 nm IHLATI (Indium Halo by Large Angle Tilt Implant) MOSFET for 1.0V Low Power Applicationxe2x80x9d by Young Jin Choi, et al. describes the use of an indium halo implant and a large angle tilt for the indium halo implant which improves the short channel device characteristics of the device.
Other related articles in this field of endeavor include: xe2x80x9cHigh Carrier Velocity and Reliability of Quarter-Micron SPI (Self-Aligned Pocket Implantation) MOSFETsxe2x80x9d by A. Hori, et al. and xe2x80x9cA 0.1-xcexcm CMOS Technology with Tilt-Implanted Punch-through Stopper (TIPS)xe2x80x9d by T. Hori.
None of the above cited prior art references provides a method of improving the abruptness of the halo dopant profiles in the area next to the channel. Instead, in the prior art processes, the halo implants will suffer enhanced transient diffusion during extension junction and high thermal budget deep source/drain rapid thermal annealing (typically on the order of about 1000xc2x0 C. for about 5 seconds). Consequently, these much degraded halo implant regions severely compromise their usefulness for improving short channel device characteristics, which is especially the case for device channel widths below 50 nm. Thus, all the prior art approaches provide no means to minimize transient enhanced diffusion of the halo dopants and hence the prior art approaches are not capable of creating abrupt super-halo implants in the region next to the channel region.
Another problem with prior art approaches is that permanent spacers are typically required to be formed on the structure after junction formation, but prior to low-temperature silicidation. The permanent spacers are employed in the prior art to keep the silicide formed over the junctions away from the gate region. That is, if permanent spacers are not employed, the silicide contact may bridge onto the gate region. Hence, the silicide regions formed in the prior art are not self-aligned to the deep junction edge. Additionally, such a prior art approach may result in the junction being deactivated since the dopants solubility is lower at the silicidation temperature and the dopants can move off of substitutional lattice sites.
In view of the drawbacks mentioned hereinabove regarding prior art approaches, there is a continued need for providing a new and improved method to form low temperature silicide contacts which are self-aligned to the deep junction edges. Additionally, a method is also needed that is capable of making abrupt shallow junctions and halo implants that do not require a large post-halo thermal budget.
One object of the present invention is to provide a method of fabricating a complementary metal oxide semiconductor (CMOS) device that includes a low temperature silicide that is self-aligned to the deep junction edges present in the device.
Another object of the present invention is to provide a method wherein a low thermal budget is used in fabricating a CMOS device.
A further object of the present invention is to provide a method of fabricating a CMOS device that includes a self-aligned silicide region that is formed without the need of a second spacer.
A yet further object of the present invention is to fabricate a raised or non-raised source/drain (S/D) CMOS device, wherein all high temperature processes, such as source/drain anneals and selective epi growth, are performed prior to halo formation.
A still further object of the present invention is to provide a method of fabricating a CMOS device having abrupt junction profiles therein.
These and other objects and advantages are achieved in the present invention by utilizing a gate sidewall composite spacer, which is partially removed during device processing. The inventive method is capable of forming low temperature silicide contacts which are self-aligned to the deep junction edges, while still achieving the low thermal budget of conventional disposable spacer processes.
The inventive spacer is formed by deposition of a bilayer of a thin nitride followed by a thicker Si-containing film and subsequent patterning to form sidewall spacers. The source/drain regions defined by the sidewall spacer are then formed via ion implantation, after which the thick Si-containing layer of the spacer is removed, leaving the thin nitride layer of the composite spacer on the structure. The nitride layer is thereafter etched so as to form L-shaped nitride spacer on the structure. Source/drain extension regions and halo implant regions are formed by implanting through the thin horizontal elemental of the L-shaped nitride spacers. Subsequently, this allows for the formation of silicide contacts that are self-aligned to the source/drain junction, without the need for deposition of a second, non-self aligned spacer.
The inventive method thus allows for the fabrication of a raised or non-raised S/D CMOS device with all high temperature processes such as source/drain anneals and selective epi growth occurring prior to halo formation. Moreover, the inventive method provides a manner to align the subsequent silicide contact away from the shallow junction. The method of the present invention also eliminates the need to form any separate permanent spacer. Other disposable spacer schemes known to the inventors do not have a built-in method to align the silicide contact after halo formation. Moreover, the prior art schemes require a permanent spacer which does not permit self-alignment of the silicide contact and junction edges.
One aspect of the present invention thus relates to a CMOS device which includes an L-shaped nitride spacer formed on each vertical gate sidewall. Specifically, the inventive CMOS device comprises:
a plurality of patterned gate stack regions formed on a surface of a semiconductor substrate, wherein said plurality of patterned gate stack regions each includes an L-shaped nitride spacer formed on exposed vertical sidewalls thereof, said L-shaped nitride spacer having a vertical element and a horizontal element, said horizontal element is formed on a portion of said substrate that abuts the patterned gate stack region; and
silicide contacts formed on other portions of said semiconductor substrate between adjacent patterned gate stack regions not containing said horizontal element of said L-shaped nitride spacer, said silicide contacts being self-aligned to deep junction edges formed in said semiconductor substrate.
In one embodiment of the present invention, the silicide contacts are formed on a selective epitaxial Si layer that is grown on the surface of the semiconductor substrate.
Another aspect of the present invention relates to a method of forming the aforementioned CMOS device. Specifically, the inventive method comprises the steps of:
(a) providing a plurality of patterned gate stack regions on a surface of a semiconductor substrate, wherein each of said patterned gate stack regions includes exposed vertical sidewalls;
(b) forming a composite spacer on each exposed vertical sidewall, said composite spacer including a bilayer comprising a nitride layer and a Si-containing film, wherein said Si-containing film is thicker than said nitride layer and is formed on said nitride layer;
(c) forming deep source and drain regions in said surface of said semiconductor substrate;
(d) removing said Si-containing film and forming shallow junctions in said semiconductor substrate in areas abutting each of said patterned gate stack regions;
(e) removing portions of said nitride layer so as to form an L-shaped nitride spacer on each vertical sidewall of said patterned gate stack regions and activating said source and drain regions; and
(f) forming silicide contacts in exposed regions of said semiconductor substrate not containing said L-shaped nitride spacer.
In one embodiment of the present invention, a selective epi Si layer is formed on exposed regions of the semiconductor substrate, after junction formation, but prior to performing step (f). This embodiment of the present invention forms raised source/drain areas in the CMOS device.
In another embodiment of the present invention, halo and source/drain extension regions are formed in the substrate after formation of the source/drain regions, but prior to forming the silicide contact.

All-in-one disposable/permanent spacer elevated source/drain, self-aligned silicide CMOS

International Business Machines Corporation


The disclosed computer-implemented method for displaying search results may include (1) receiving a search query to search a document database that stores a document family containing a parent document and a child document that depends from the parent document, (2) determining that both the parent document and the child document satisfy a degree of relevance to content of the search query, and (3) in response to determining that both the parent document and the child document satisfy the degree of relevance to content of the search query, automatically depicting both the parent document and the child document in a hierarchical structure that shows the relationship between the parent document and the child document within original search results that a user interface of a computing device presents in response to the search query. Various other methods, systems, and computer-readable media are also disclosed.

When a user performs a search for documents within a database, a search engine may analyze and filter the documents within the database to provide the most relevant results. Some documents returned to the user may be part of a family of related documents, such as a file embedded within another file or an email with corresponding email attachments. For example, in an e-discovery platform, users may search a document database for documents related to a specific search query. In response, the e-discovery platform may return one or more members of a document family that are related to the search query.
Traditional methods for providing the results of a document search to a user may include listing or displaying each document that corresponds to a set of search criteria. For example, a search engine may list documents in an order corresponding to their relevance to the search criteria. Unfortunately, such conventional methods for displaying search results may not provide users with important and/or helpful associations between groups of related documents. For example, even if a database stores associations between documents in document families, traditional search engines may request that users provide additional input (e.g., after the original search results are displayed) in order to view documents organized based on their relationships with one another. Accordingly, the current disclosure identifies a need for improved methods for displaying search results.

Systems and methods for displaying search results


Encrypted email message structures can contain recipient information that can reveal, to any recipient, all of the other recipients of an email message. Because some recipients, such as recipients to whom the message was “blind carbon-copied”, should remain hidden from the other recipients, individual encrypted messages can be created. One encrypted message can be created for all of the recipients who are intended to be revealed, such as the recipients listed in the TO and CC fields of an email header. A second encrypted message can be created for all of the recipients of the message who are intended to be hidden, such as the recipient listed in the BCC field of an email header. Alternatively, multiple encrypted messages can be created individually for each recipient in the BCC field, if the BCC recipients are to be hidden even from other BCC recipients.

Electronic mail, or email, has become a ubiquitous element of modern communications. Many credit the explosive growth of the Internet, and internal corporate networks, to the ability of people to communicate and work together through email. In an effort to ensure that email from many different computing platforms can be seamlessly exchanged among the platforms, standards have been developed defining the structure of email messages, and the protocols and mechanisms used to transport and deliver those messages.
One standard for governing the transmission of email messages is known as the Simple Mail Transfer Protocol, or SMTP. SMTP defines a series of commands that computing devices can use to transfer email messages from one computing device to another. Generally, SMTP allows two computing devices to establish a two-way transmission channel to transfer one or more pieces of mail in three basic steps. A first step can transfer information regarding the sender of the email message, a second step can transfer information regarding the intended recipients of the email message, and a third step can transfer the actual contents of the email message itself.
Because of the distributed nature of networks, including the Internet, SMTP contemplates that a single email message from a sender to a recipient may be transmitted in the above described manner multiple times between intermediate host computing devices. When an intermediate host computing device receives an email message for further transmission, it can initiate another SMTP channel with a further computing device and conduct a similar transfer. However, once the email is received at its final destination, the contents of the email message can be presented to a user through an email reader program or the like.
To further ensure the seamlessness of email messages as they are exchanged between platforms, the structure of the mail data itself can also be standardized. One standard for the structure of email messages is known as the Internet Message Format. The Internet Message Format divides mail data into lines of characters having a maximum length. An email message can comprise header fields and a body containing the text or other data that one user wished to transfer to other users. The header fields can be composed of a field name and a field body. Commonly recognized field names include the TO, FROM, DATE, CC and BCC. While such fields may contain similar information as is transferred between computing devices via an SMTP channel, the header fields are visible to readers of the email message, while the information transferred as part of the first two steps of an SMTP transfer can be exclusively used by mail transferring programs.
Of particular concern can be the treatment of the recipients listed in the BCC field. The BCC field, or "blind-carbon-copy" field, is intended to provide email senders a mechanism by which they can send email messages to certain individuals without allowing other recipients of the same message to know that those individuals received a copy. For example, senders may wish to protect the identity of certain recipients or they may wish to protect the email address of certain recipients. Therefore, while all of the recipients BCCed on an email message can appear, in the form or an email address, as one of the arguments transferred with an SMTP RCPT command, those same recipients may not appear in the BCC header field of the email data sent to other recipients.
Three possibilities are defined for protecting the identity of recipients listed as BCCed on an email message. Prior to transmitting the email, the sending computing device can remove the BCC header from the email data and then transmit the message to all of the recipients. Alternatively, the BCC header can be removed only from the email data sent to the recipients listed in the TO and CC header fields, while the recipients listed in the BCC header field can receive an alternative email data containing the BCC header field. A third defined possibility allows the transmission of a blank BCC header field to all of the recipients.
As can be seen from the above description, an email message can be represented as an envelope of data, with the envelope containing information regarding the sender and recipients of the data, and the data containing header information and additional data intended for the recipient. Protocols such as SMTP can define a transfer mechanism for the envelope, including the sender and recipient information, and protocols such as the Internet Message Format can define an interpretation mechanism for the data contained in the envelope.
However, neither SMTP nor the Internet Message Format provide protection against tampering. Thus, a malicious user or computing device could intercept email messages, and alter their contents. To prevent such tampering, a secure encoding scheme, such as S/MIME can be used. The Multipurpose Internet Mail Extensions (MIME) encoding scheme establishes a common mechanism by which any data can be transferred by the above described protocols. Specifically, the MIME encoding scheme allows data to be encoded into a text-based format, and provides headers which can specify the type of data that is encoded, to aid in the decoding of the data by the recipient.
The Secure Multipurpose Internet Mail Extensions (S/MIME) encoding scheme can be used with the Cryptographic Message Syntax (CMS) to provide mechanisms by which the content of an email message, including any MIME encoded data contained within the message, can be encrypted in such a manner that each recipient listed in the headers of the message receives the encrypted data and an encryption key encrypted specifically for that recipient. This encrypted data can then either be attached to a part of the message that is not encrypted, together with MIME headers specifying the encryption of the data, and the email message headers. Such an encrypted email message can then be transmitted through ordinary message transmission algorithms, such as SMTP, while protecting the contents of the email message from malicious attacks.
The combination of S/MIME and CMS can sign data and encrypt data in various combinations to protect the content of an email message. For example, a textual message that is to be sent securely using the S/MIME encoding scheme can first be converted to a canonical form that is representable on both the sending and receiving computing platforms. Once converted, it can be signed, and then the signed data can then be further encrypted for each recipient and packaged. This package can then be placed in an email message, having appropriate headers, which can further be transmitted in an envelop according to SMTP, as described above. Upon receipt by each of the recipients, the email message can be opened, the data can be unencrypted, and its integrity can be verified. In such a manner an email message can be protected during transit.
However, while S/MIME can provide for the protection of email contents, the existence of recipient-specific information in S/MIME data formats can reveal the identity of recipients that were only BCCed on the email message, even if the BCC field is removed from the header of the email. Specifically, the content of an S/MIME email message is individually encrypted for each recipient, including the recipients listed in the BCC field. Thus, even though the header may have had all BCC information removed as described above, certificate identifiers and other recipient-specific information, including information specific to BCC recipients, can still be found in an unencrypted form as part of the encrypted email package. Consequently, by merely referencing this unencrypted, recipient-specific information, the identity of all recipients, including BCC recipients can be determined by any recipient.

Encryption to BCC recipients with S/MIME


Embodiments relate to monitoring computing hardware in a computing infrastructure facility. Image data and environmental data are received and a current operational status for a computing hardware component is determined from the image data. A hardware operational status tracking model and environment tracking model for the computing hardware component are updated. Embodiments can perform a root cause analysis if the current operational status is a fault status to determine if the fault status was caused by environmental conditions.

The present invention relates to monitoring operational conditions of computing infrastructure facilities, and more specifically, to noninvasively monitoring computing hardware for fault conditions.
In current computing infrastructure facilities, such as colocation data centers, the managers, owners, and/or providers of the facility provide the facility (e.g., building space) to house computing hardware. Failure of various computing hardware housed in the computing infrastructure facility is known to occur due to various reasons including data center facilities environmental factors such as temperature, humidity, and contamination apart from other reasons related to wear and tear. The providers of the facility need the ability to determine whether the cause of a failure is environmental or due to hardware wear and tear. In current computing infrastructure facilities, a management console must be used to access the information related to hardware failures the various computing hardware. To ensure privacy and security of the computing hardware and the data created, transmitted, and/or stored on the computing hardware the facility providers may not have direct access to the computing hardware to determine the cause of hardware failures. In addition, the heterogeneous nature of the equipment used in computing infrastructure facilities, including different types of computing hardware (servers, networking, storage, etc.) and different computing hardware manufacturers complicates facility providers' effective monitoring of the computing hardware.

System to monitor computing hardware in a computing infrastructure facility

International Business Machines Corporation


A short-length, belt fed machine gun for convenient use includes: (A) a receiver having a length in the range of about 17.75 inches to about 20.3 inches, (B) a barrel assembly, and (C) a gas cycling assembly. A gas port of the barrel assembly has a width of between about 0.063 inches and 0.200 inches. The distance between a center of the gas port and the breach of the barrel is between about 7.605 inches and about 9.395 inches. The gas cycling assembly features a unique polymer kinetic energy dampener assembly located longitudinally rearward of the operating rod, which is useful in achieving a desired cycle rate of the gun (e.g., about 600 rounds per minute (RPM)) and in minimizing muzzle climb. A unique mounting bushing selectively, removably mounts to the gas cylinder in order to achieve a shortened gun with many of the advantages of conventional longer weapons.

Machine guns were developed with the goal of expending great numbers of bullets in short periods of time. While this capability has tactical advantages in many scenarios, maximum rates of fire are not always desirable for a number of reasons. For instance, ammunition is heavy and the storage and transportation thereof can be unwieldy. An individual user tasked with operating a handheld machine gun with a high ammunition cycle rate must either limit their mobility by carrying a large amount of ammunition or limit their firing behavior to conserve ammunition. Additionally, as cycle rates increase, it becomes more difficult to maintain accuracy as each cycle has a jarring effect on the weapon and the user that affects aim and accuracy.
Many conventional machine guns are, therefore, team-operated weapons that are carried, fed, and operated by more than one operator. While a machine gun offers tactical advantages, the advantages are diminished by dedicating more than one individual to operating the machine gun. For example, a primary application of a machine gun in a squad is to provide suppression of the enemy and provide a mobility advantage to the operator's cohorts. A single operator further increases the mobility of the group. Furthermore, increasing cycle rates above 600 rounds per minute provides little additional suppression capability. In fact, lower cycle rates allow skilled operators to more precisely control the quantity of rounds fired with each trigger pull.


The invention relates to a filter arrangement comprising a plate-shaped filter holder (12) provided with at least one stem-type protruberance (13) having an opening (11) said filter holder (12) being used to receive a filter element (14) in a sealed manner for each protuberance on the raw gas side of the filter holder. In order to ensure that the filter is changed easily with sufficient filtering safety, each filter element (14) is provided with an adapter collar (15) comprising at least one limb (15B; 15D) parallel to the protruberances. Said limb can be placed, from the raw gas side, inside or over the protruberance. A sealing arrangement (16) provided comprises sealing elements (16A, 16B) which are parallel to both the plates and to the protruberances and are used for the at least partial join between the protruberance and the adapter collar.

Filter elements that can be assembled or installed as construction units in a filter arrangement, in a number corresponding to the need, are usually screwed in a sealing manner on a plate-shaped filter holder, such as, for example, according to DE 203 12 074 U1, FIG. 1 which is incorporated by reference as background material for showing the same.
A typical application of generic filter arrangements consists of the so-called vacuum conveyance installations, as known from DE 203 12 074 U1, which presents a collection container for transported material that is aspired by a vacuum. The negative pressure of a vacuum pump is applied to the collection container, and the transported material is deposited by gravity on the bottom of the collection container, while the suction air leaves the collection container at the top through the opening of the plate-shaped filter holder. Already for the protection of the vacuum pump, and for the complete use the transported material, only the suction air is allowed to pass to the vacuum pump through the filter elements that close the openings, and not the transported material or dust components. Such filters, which can be made from ceramic, flow material or other filter surface material, present as a rule a cartridge shape (hanging cartridge). If the performance of a filter cartridge worsens or if the filter cartridge contains cracks and has to be replaced, in spite of regular counter-pressure cleaning, the cost is similarly high.
In the case of filter hoses in fine dust filters, the raw gas side hose openings are usually clamped between conic rings, and the external ring is screwed to the plate-shaped filter holder that is provided with openings (DE 41 34 679 A1) which is incorporated by reference as background material for showing the same. The external holder ring can also be welded to the perforation margin or the filter holder can be designed as one piece with the filter holder (DE 40 31 375 A1) which is incorporated by reference as background material for showing the same. The filter hoses can be replaced by removing an inner cone on their gas inlet opening, where the hose opening can present a bead-like clamping margin (DE 816 852 C) which is incorporated by reference as background material for showing the same.
Filter arrangements with adaption collars connected to the filter elements are also known. Thus DE 203 12 074 U1 presents a two-part adaption collar (FIGS. 1 and 2), which is screwed by means of a flange-like protruding attachment sheath with external threading and with the interposition of a ring seal with a flat, perforated filter holder plate, so that the attachment sheath and the adaption collar clamp the flat filter holder on opposite sides between themselves. The handling of such a filter arrangements during the filter replacement requires a certain degree of skill so that the desired lasting seal can also be achieved. Instead of a screw connection, DE 90 14 198 U1 which is incorporated by reference as background material for showing the same provides fixation pins on the pure gas side acting on an adapter flange of the filter element. For their fixation, it is necessary to weld an annular attachment collar for the fixation pins with considerable radial separation from the perforation of the flat filter holder plate to the latter. It is only in this way that the cartridge-shaped filter element, which is provided with its adapter flange forming a single piece, can be slid from the pure gas side, with interposition of a sealing collar, into the attachment collar, and put on the pure gas side on the plate-shaped filter holder. The insertion of the filter cartridge from the top is an impediment in many applications, and disadvantageous for the sealing function because of the raw gas pressure applied from below.
Generic filter arrangements, which are the starting point of the invention, present at least one neck-shaped protuberance of the plate-shaped filter holder. They are known from U.S. Pat. No. 3,997,305, among others, which is incorporated by reference as background material for showing the same. According to the latter patent, a spreading basket with a filter hose that is placed around its opening over the neck-shaped protuberance and pulled in a sealing manner close to the external margin of the neck-shaped protuberance by an external clamping ring. To receive venturi-like nozzles in the interior of the hose, a piece of pipe with stepped diameter is slid into the neck-shaped protuberance, and welded firmly to it. An additional generic hose filter arrangement is known from DE 203 12 074 U1, FIG. 4B. In both known applications of plate-shaped filter holders with neck-shaped protuberances forming an opening, which are the starting point of the invention, no special sealing arrangements are used. Rather, the purpose is to have the filter hose be applied in a sealing manner on the external circumference of the neck-shaped protuberance under the radial pressure of a clamping means. According to DE 203 12 074 U1, the neck-shaped protuberance serves in addition as a welding collar for the lasting attachment of a non-replaceable filter cartridge with support function for the filter hose. The generic filter arrangements are in fact easy to manufacture and flow enhancing; however, the clamp attachment of the filter hose that has been put over is found to be time consuming. In addition, such filter arrangements have been unsuitable so far for finished filter elements consisting of a filter cartridge with prefabricated adaption collar.


The present invention provides an improvement over conventional electric circuit monitoring devices in that it provides a device and method to passively monitor the performance of an electrical circuit to a load device, including faults that occur intermittently. The invention is capable of identifying the location and type of malfunction in the event of a fault.

This invention relates to control and diagnosis of driver circuits and wiring harnesses for electrical load devices, including electromagnetic actuators and resistive devices such as lamps.
Electric load devices such as electromechanical actuators and lamps are used in a variety of applications in industrial controls, motor vehicles and other devices. Industrial applications include, for example, robotics and electrically controlled valves for chemical process systems. Vehicle applications may include fuel injection systems, electronic transmissions, evaporative purge control systems, antilock braking systems, intake/exhaust valve control systems, lighting systems and others. Typically a circuit will comprise the load device located in a remote area where control or power is needed with a remote driver that is connected to the driver with a wiring harness.
A circuit for an electric load device is used primarily to control the device, but may also be used to monitor performance of the device. When a fault occurs in a circuit, the effect in an industrial setting will be machine downtime and a resulting loss in productivity. The effect on a motor vehicle can include unacceptable system performance and damage to related systems and components, or an increase in emissions of the vehicle. The increase in emissions has become important with the advent of government regulations that compel addition of on-board vehicle diagnostic systems to monitor emissions related components and control systems. The intent of the on-board diagnostic systems is to detect faults that lead to emissions increases.
There is a need to identify a specific location of a fault once it has been detected to ensure that any fault can be quickly located and effectively repaired. This need to identify the location of a fault is important to minimize a loss of productivity associated with machine downtime in a factory, or to minimize costs to diagnose and repair a system on a vehicle.
When a fault occurs in a system, there is a need to identify the type and location of the fault to facilitate repair. When a fault occurs on a vehicle a diagnostic fault indicator may be set. This fault indicator typically will identify the system where a fault has occurred, but will lack sufficient specificity to identify where a specific repair needs to occur. The diagnostic fault indicator will lead a repair technician to a system whose performance may be affected by an interaction of several components or subsystems. The technician may be compelled to work through multiple diagnostic procedures to locate and repair the fault. This consumes time and resources, and results in increased cost and decreased satisfaction to the vehicle owner.
The ability to correctly detect and identify a fault is more difficult when the fault is intermittent, as may occur when there is water intrusion into a wiring harness or connector. A technician will spend time and resources in attempting to reproduce failure conditions to identify a fault or verify a repair. This can result in customer dissatisfaction and high costs to the customer or the manufacturer, due to multiple attempts to identify and repair intermittent faults in a circuit. This problem is apparent when a fault occurs that sets a general diagnostic code that lacks sufficient specificity to identify a needed repair.
Electric load circuits can include devices such as insulated wires, connectors, drive transistors or relays, wiring junctions, and fuses. Faults in the circuit that can lead to undesirable operation of an electric load system include wiring harness shorts to ground, wiring harness open circuits, and wiring harness intermittent connections. Other faults include broken or abraded wires, and connector faults such as relaxation of terminals, or corrosion due to intrusion of water or contaminants.
There are standard methods existing to diagnose and repair faults using off-board techniques such as connectivity tests and diagnostic trouble trees. These methods and tools are contained in service manuals, and are well known in the art. Off-board techniques require the employment of intrusive test methods, including the use of hand held scan tools used by a skilled technician. The prior art has sought to diagnose faults in electrical load circuits on-board the vehicle through the addition of current-monitoring devices that add cost and complexity to the circuit. These may be effective in diagnosing fault in a specific solenoid, but do not diagnose faults in the circuit leading to the electrical device. The prior art has also sought to identify the presence and location of faults with on-board intrusive methods and systems that send a signal through a circuit to a device and look for an subsequent output from the device. These methods can be disruptive when they occur during normal operation of the vehicle or the system. The prior art also has not addressed the issue of identifying the presence of an intermittent fault in a circuit, and the related result of being able to focus the repair efforts of a technician to a specific location in the system.
The present invention is an improvement over conventional electric circuit monitoring devices in that it provides a device and method to passively monitor the performance of an electrical circuit to a load device, including faults that occur intermittently. The invention is capable of identifying the location and type of malfunction in the event of a fault. Accordingly, the invention provides a complete apparatus and method to control and diagnose driver circuits for electromagnetic actuators and resistive load devices, and detect faults therein.
The present invention includes a circuit and methods that are able to control and monitor an electric load. It includes the electric load, a first switch electrically coupled to a power supply and one end of the electric load, and a second switch electrically coupled between the second end of the electric load and ground. The switches are controlled by a load drive controller that communicates with an external controller. Detection of a fault condition in the circuit occurs by comparing an electric potential at one end of the electric load with a first known potential, and by comparing an electric potential at the second end of the electric load with a second known potential. The circuit accomplishes the comparison using, for example, discrete electronic comparators. The inputs from the electric load and the first and second known potentials are appropriately biased with an effective amount of electric potential to enable detection of a type and location of a fault condition. The output from each of the comparators is communicated as an indication of a fault. This is a passive monitoring system. When a fault is detected, the circuit will operate to identify a location and type of fault, by controlling the switches and monitoring the output of the comparators. The output from the comparators can be communicated to an external controller to indicate the type and location of the fault.
The present invention also comprises a method for controlling and monitoring an electric load. This includes providing a circuit comprising an electric load with a first switch electrically coupled between a power supply and the electric load. The circuit also includes a second switch electrically coupled between the electric load and ground, and a load drive controller operable to control each switch. The method operates by activating the switches. It then compares an electric potential at the first end of the electric load with a first known potential, and also compares an electric potential at the second end of the electric load with a second known potential. The method will then obtain an output from each comparison. The output can then be communicated to an external controller to indicate a fault. The method can also detect the type and location of any fault condition using the comparison of electric potentials. The electric potentials at the first and second ends of the electric load and the first and second known potentials are appropriately biased to detect the type and location of a fault condition. The outputs from the comparisons are then communicated and indicate the type and location of the fault.
A feature of this invention is to provide a circuit to control an electric load and monitor for faults in the circuit. The circuit is also able to identify the type and location of a fault, and communicate this information.
Another feature of this invention is to provide a method for controlling an electric load and monitoring for faults in the circuit. The method is also capable of identifying the type and location of a fault, and communicating this information.
These and other features of the invention will become apparent to those skilled in the art upon reading and understanding the following detailed description of the embodiments.

Method and apparatus for control and fault detection of an electric load circuit