A method of fabricating a semiconductor device includes forming an insulating film above a semiconductor substrate, forming a concave portion in the insulating film, forming a precursor film including a predetermined metallic element on a surface of the insulating film, carrying out a heat treatment on the precursor film and the insulating film to react with each other, thereby forming an insulative barrier film mainly comprising a compound of the predetermined metallic element and a constituent element of the insulating film in a self-aligned manner at a boundary surface between the precursor film and the insulating film, removing an unreacted part of the precursor film after forming the barrier film, forming a conductive film comprising at least one of Ru and Co on the barrier film, depositing a wiring material film on the conductive film, and forming a wiring from the wiring material film to provide a wiring structure.

As a conventional method of fabricating a semiconductor device, a method of fabricating a semiconductor device having a wiring structure in which a barrier film for suppressing Cu-diffusion is formed in a self-aligned manner between a wiring main body layer mainly comprising Cu and an interlayer insulating film. For example, Japanese Patent Laid-Open No. 2005-277390 discloses such a method of fabricating a semiconductor device.
This barrier film mainly comprises a compound of a predetermined metallic element such as Mn and a constituent element of the interlayer insulating film. Since this predetermined metallic element easily forms an oxide, when a reactive layer is once formed, a reaction rate of the oxygen from the insulating film with the metallic element becomes extremely slow. Therefore, a substantial reaction does not advance, so that the homogeneous, super thin and stable barrier film is formed between the wiring main body layer and the interlayer insulating film.
According to this method of fabricating a semiconductor device, a Mn—Cu alloy film, for example, is formed in a wiring trench formed at the interlayer insulating film, and a Cu film which is a material of the wiring is deposited thereon. The barrier film is formed between the Mn—Cu alloy film and the interlayer insulating film by carrying out heat treatment on the Mn—Cu alloy film and the Cu film. Simultaneously, Mn diffuses in the Cu film, and is precipitated as the insulating film mainly comprising a Mn oxide at a surface of the Cu film. Mn can be removed from the Cu film by removing the insulating film mainly comprising the Mn oxide.
However, according to this method of fabricating a semiconductor device, since a Cu film is deposited to have a thickness of 0.8 to 1.0 μm, when the insulating film mainly comprising the Mn oxide is precipitated on the surface of the Cu film, a part of Mn does not reach the Cu film surface and may remain within the Cu film. The residual Mn causes the increase in a specific resistance of the wiring as impurity metal.
In addition, according to this method of fabricating a semiconductor device, it is also possible to use a technique of carrying out a heat treatment to form a barrier film before depositing the Cu film on the Mn—Cu alloy film. However, according to this method, the Cu film formed on a surface of the barrier film aggregates when the barrier film is formed, so that a Cu film deposited on the barrier film may be peeled off.

Semiconductor device and method of fabricating the same


A hysteresis circuit according to the invention has a thyristor circuit 101 which outputs a low voltage in an on-stage thereof, and outputs a high voltage in an off-state thereof. When an input voltage exceeds the threshold voltage of a first switching circuit 102, the circuit 102 turns on the thyristor circuit. On the other hand, when the input voltage exceeds the threshold voltage of a second switching circuit 103, the circuit 103 turns off the thyristor circuit.

The Schmidt Trigger circuit is well known as a switching circuit which operates in a hysteretic manner.
FIG. 1 shows an example of the Schmidt Trigger circuit. As is shown in FIG. 1, the base of an npn transistor Q1 is connected to an input terminal Vin. A resistor R1 has one end connected to the collector of the transistor Q1, and the other end connected to a power source terminal V.sub.DD. A resistor R2 has one end connected to the emitter of the transistor Q1 and the other end connected to an earth terminal Vss. The base of an npn transistor Q2 is connected to the collector of the transistor Q1, while the collector of the transistor Q2 is connected to an output terminal Vout. A resistor R3 has one end connected to the collector of the transistor Q2 and the other end connected to the power source terminal V.sub.DD. The emitter of the transistor Q2 is connected to the one end of the resistor R2.
The maximum hysteresis error of the above circuit is determined by the values of the resistors R1-R3. The output voltage of the circuit varies from a low voltage (hereinafter called "L") to a high voltage (hereinafter called "H") when the transistor Q1 is turned on, while it varies from "H" to "L" when the transistor Q2 is turned on. That is, when one of the transistors Q1 and Q2 is on, the other is off.
The Schmidt Trigger circuit shown in FIG. 1 operates in a hysteretic manner as shown in FIG. 2. Then, this operation will be explained with reference to FIGS. 1 and 2.
When the transistor Q2 is on, and the transistor Q1 is off, the output voltage is "L". Thereafter, the input voltage Vin increases, and reaches a value which satisfies the following formula (1). At this time, the transistor Q1 is turned on, and accordingly the transistor Q2 is turned off. Thus, the output voltage varies from "L" to "H". EQU Vin>V.sub.th(L.fwdarw.H) =V.sub.DD .times.R2/(R2+R3)+V.sub.BEQ1 (1)
where V.sub.BEQ1 represents the threshold voltage of the transistor Q1, and V.sub.th(L.fwdarw.H) represents that threshold voltage of the Schmitt trigger circuit which is assumed when the output voltage varies from "L" to "H". Further, the earth voltage is applied to the earth terminal Vss, and the saturation voltage of the transistor Q2 is ignored.
Thus, the output voltage Vout varies in the order of a, b, c, d, and e in FIG. 2.
When the input voltage Vin reduces, and reaches a value which satisfies the following formula (2), the transistor Q2 is turned off, and the transistor Q1 is turned on. Thus, the output voltage varies from "H" to "L". EQU Vin<V.sub.th(H.fwdarw.L) =V.sub.DD .times.R2/(R1+R2)+V.sub.BEQ1 (2)
where V.sub.BEQ1 represents the threshold voltage of the transistor Q1, and V.sub.th(H.fwdarw.L) represents that threshold voltage of the Schmitt trigger circuit which is assumed when the output voltage varies from "H" to "L". Further, the earth voltage is applied to the earth terminal Vss, and the saturation voltage of the transistor Q2 is ignored.
Thus, the output voltage Vout varies in the order of e, d, f, b, and a in FIG. 2.
In the above embodiment, the values of the resistors R1 and R3 are determined so as to satisfy the following formula (3): EQU Vth(L.fwdarw.H)>Vth(H.fwdarw.L) R1>R3 (3)
This means that the hysteresis characteristic is obtained by setting to different values the threshold voltages V.sub.th(L.fwdarw.H) assumed when the output voltage varies from "L" to "H", and V.sub.th(H.fwdarw.L) assumed when the output voltage varies from "H" to "L".
However, as is evident from the formula (1), the threshold voltage V.sub.th(L.fwdarw.H) assumed when the output voltage varies from "L" to "H" is determined by the resistance ratio between the resistors R1 and R3. Similarly, as is evident from the formula (2), the threshold voltage V.sub.th(H.fwdarw.L) assumed when the output voltage varies from "H" to "L" is determined by the resistance ratio between the resistors R1 and R2. Accordingly the threshold voltages V.sub.th(L.fwdarw.H) and V.sub.th(H.fwdarw.L) depend upon each other, and hence, must be set to values falling within a very narrow range.
In addition, in a case where the Schmidt Trigger circuit comprises an integrated circuit, great variations may exist among Schmidt Trigger circuits if the ratio of the largest resistance of the resistors R1-R3 to the smallest resistance of them is set to a large value. Further, as can be understood from the formulas (1) and (2), the threshold voltages V.sub.th(L.fwdarw.H) and V.sub.th(H.fwdarw.L) vary in accordance with a change in the power source voltage V.sub.DD. Hence, a constant voltage source dedicated for supplying the threshold voltages is required in the integrated circuit.
It is the object of the invention to provide a hysteresis circuit in which the threshold voltage V.sub.th(L.fwdarw.H) assumed when the output voltage varies from "L" to "H", and the threshold voltage V.sub.th(H.fwdarw.L) assumed when the output voltage varies "H" to "L" are set independently of each other, and do not vary in accordance with a change in the power source voltage of the circuit.


A braking force retaining unit has a cut-off valve and a control unit. The cut-off valve retains predetermined brake hydraulic pressure at the wheel cylinders until a predetermined releasing condition is established, even after the depression of a brake pedal is released when a vehicle is stopped. When the predetermined releasing condition is established, the retained brake hydraulic pressure is released, when the depression of the brake pedal is released, the control unit controls the cut-off valve so as to retain the brake hydraulic pressure while reducing the retained brake hydraulic pressure at a first reduction rate. When the predetermined releasing condition is established, the control unit controls the cut-off valve so as to allow the retained brake hydraulic pressure to be reduced at a second reduction rate which is faster than the first reduction rate.

1. Field of the Invention
The present invention relates to a braking force retaining unit which can retain a braking force even after the depression of a brake pedal has been released.
2. Description of the Background Art
A braking force retaining unit is configured to include an electromagnetic or solenoid valve which operates electromagnetically at an intermediate position along the length of a brake hydraulic circuit so as to cut off the brake hydraulic circuit by supplying the solenoid valve with an electric current, whereby even after the driver releases the depressed brake pedal, brake hydraulic pressure (braking force) is retained at the wheel cylinders. As a result, the vehicle is, for example, prevented from moving backward from its own weight when attempting to start climbing up a rising slope. Then, in the event that the retained brake hydraulic pressure is made zero or made to collapse totally at one time, occupants of a vehicle have to be made to feel a feeling of some abruptness or physical disorder, which is not preferable from the viewpoint of product quality. Due to this, in JP-A-2001-354126 (FIGS. 4, 8, 12 and the like), when releasing a retained brake hydraulic pressure, a time difference is provided in release initiating timing between two crossed brake hydraulic pressure circuits (crossed brake pipe lines).
However, in order to enable a smoother start, the feeling of abruptness and physical disorder that the occupants of the vehicle are forced to feel needs to be reduced further. In addition, in the case of JP-A-2001-354126, in the event that a large time difference is set in release initiating timing between two crossed brake hydraulic pressure circuits, since a behavior such as one in which a body of the vehicle is twisted in some way is generated in the crossed brake pipe lines, there is imposed a limitation on setting of time. Hence the compatibility of the reduction in a shock felt by the occupants when the applied brakes are released with the reduction in the behavior in which the body of the vehicle is twisted needs a certain compromise.


A half-tone phase shift mask capable of preventing light from being transmitted in undesired areas, and thus capable of obtaining desired fine patterns. The present invention is to provide a photomask for simultaneously forming photoresist patterns on a first area in which fine patterns are to be formed and on a second area in which relatively large photoresist patterns are to be formed in a semiconductor device. The photomask comprises a transparent substrate, half-tone phase shift patterns disposed on the first area of the transparent substrate and light screen patterns disposed on the second area of the transparent substrate.

1. Field of the Invention
The present invention relates to a phase shift mask, and more particularly to a half-tone phase shift mask capable of preventing light from being transmitted in undesired areas, and thus capable of obtaining desired fine patterns.
2. Description of the prior Art
With the development of the highly integrated circuits, such as highly integrated dynamic random access memory devices, the demand for fine patterns is on the increase. In an effort to reduce the pattern size, a half-tone phase shift mask has been developed.
Generally, a half-tone phase shift mask is comprised of a quartz substrate and mask patterns including two layers, a light screen material layer and a phase shift material layer. In the half-tone phase shift mask, the light screen material layer is made of a chrome layer which transmits an incident light to a predetermined transmissivity. The phase shift material layer formed on the light screen material layer plays the role of shifting the phase of light at an angle of 180. Such a phase shift mask is designed to keep constant the amplitude of light illuminated on a wafer in the light exposing process and to minimize the light intensity caused by the interference between the light passing through the phase shift material layer and the light passing through the adjacent quartz substrate, thereby improving the resolution of the photosensitive film patterns.
FIG. 1 is a cross sectional view of photosensitive film patterns with a conventional half-tone phase shift mask. As shown in FIG. 1, positive photosensitive film patterns 15 formed on a semiconductor substrate 14 are shown with a conventional half-tone phase shift mask and the path of the incident light 16. A transparent substrate 11 has mask patterns which are made of two material layers, a chrome layer 12 and a phase sifting material layer 13. The chrome layer 12 has such a thickness so as to provide a predetermined transmissivity.
The area, which is not intended to be exposed, may be illuminated by the exposing light transmitting the mask patterns formed on the mask substrate. This causes the formation of an uneven surface on the top of the photosensitive film patterns 15. The size of the uneven surface on the photosensitive film patterns increase in proportion to the size of the mask patterns and decreases in proportion to the distance between the patterns.
Such photosensitive film patterns having an uneven surface decrease the reliability of the semiconductor devices and their yield. For example, when a photosensitive film formed by a conventional half-tone phase shift mask is used as an etching mask or as an ion implanting mask, a layer under the mask may be damaged or ions may be implanted into unintended areas.
In particular, in the process of exposing the positive photosensitive film coated on a semiconductor substrate using such a conventional half-tone phase shift mask, the area which is not intended to be exposed may become illuminated because of the transmissivity of the light passing through the mask patterns. The incident light passes through the mask patterns in the unintended areas and the intensity of the passing light is not uniform over the unintended areas. As a result, photosensitive film patterns having uneven surfaces are formed. These photosensitive film patterns have the desired height only on the edge thereof. However, the center of the photosensitive film in the area, which is not intended to be exposed, is illuminated by the passing light having weak intensity and variable kinds of intensity. Accordingly, in the process of developing, the center portion of the photosensitive film in the unintended area may be removed at different thicknesses according to the size thereof.
When light is illuminated on such a half-tone phase shift mask, the intensity of light is maximized at the center portion of a transmission region, which has no mask pattern, and the light intensity is reduced to zero at the edge of the transmission region. As stated above, the light intensity peak at the light screen areas provided with mask patterns may be detected, although it is very weak. The peak of light intensity detected in the light screen area is called a side-lobe peak.

Photomask having a half-tone type phase shift material and chrome pattern on a transparent substrate

Hyundai Electronics Industries Co., Ltd.


A selection circuit having a comparator with comparator inputs connected to first and second voltage inputs), respectively, and a comparator output connected to a control input of a first controllable switch and an inverter. The selection circuit also has a second controllable switch having a second control input connected to the inverter. The first voltage input is connectable to a selection circuit output by the first controllable switch and the second voltage input is connectable to the selection circuit output by the second controllable switch. The inverter has a power supply connector connected to the first voltage input and the comparator has a power supply connector connected to the second voltage input.

The power-up of chips that have several power supply sources is a difficult problem. Indeed, to work correctly any chip needs a minimum supply voltage. When there are several power supply sources with different voltage on each, it is necessary to determine which of these sources can provide a high enough voltage to the chip. Once this decision is taken, a mix of these valid power supply sources can be done to supply the chip. The decision or selection circuit is difficult to design because the decision circuit itself is also not supplied by one constant power supply source but by several and it has to work whatever the values of the voltages on these sources are.
As known from the prior art FIG. 1 shows a solution for a decision circuit which is used to generate a power supply from two power supply sources VDD1 and VDD2. It is based on a feedback loop.
The circuit comprises a comparator CMP with a comparator input 1 connected to a first voltage input IN1 and a comparator input 2 connected to a second voltage input IN2. The first comparator input 1 is applied with the first supply voltage VDD1 while the second comparator input 2 is applied with the second supply voltage VDD2. A first diode D1, which is connected in parallel to a first controllable switch SW1, is connected on the one side to the first voltage input IN1 and on the other side to a circuit output OVDD. A second diode D2, which is connected in parallel to a second controllable switch SW2, is connected on the one side to the second voltage input IN2 and on the other side to the circuit output OVDD. The control input of the first controllable switch is controlled by the output 3 of the comparator CMP. The output 3 of the comparator CMP is also connected to an inverter INV, whereby the output 6 of the inverter INV controls the control input of the second controllable switch SW2. Both power supply connectors 4 and 7 of the comparator CMP and the inverter INV are connected to the output voltage VDD.
The first switch SW1 is conducting, if the first control voltage SWVDD1 is lower than the difference between VDD1−Vt or if the first control voltage SWVDD1 is lower than the difference between VDD−Vt. In this case the first voltage VDD is VDD1. If the first control voltage SWVDD1 is higher than the difference between VDD1−Vt and higher than the difference between VDD−Vt, the first switch SW1 is not conducting and the voltages VDD and VDD1 are independent. The voltage Vt is a constant voltage. In principle this is also valid for the second switch SW2. The second switch SW2 is conducting, if the second control voltage SWVDD2 is lower than the difference between VDD2−Vt or if the second control voltage SWVDD2 is lower than the difference between VDD−Vt. In this case is the output voltage VDD is VDD2. If the second control voltage SWVDD2 is higher than the difference between VDD2−Vt and higher than the difference between VDD−Vt, the second switch SW2 is not conducting and the voltages VDD and VDD2 are independent.
At power-up, the diodes D1 and D2 pull up the node OVDD, which is the output of the circuit, to the voltage VDD equal to the maximum of the three values VDD1−Vdiode, VDD2−Vdiode or O. The voltage Vdiode is the diode voltage and is equal for both diodes D1 and D2.
If this voltage VDD is lower than the constant voltage Vt, the comparator output 3 and the inverter output 6 will be floating and therefore be undefined. In some cases, this can lead to a large short circuit current. Let's assume for example that the first supply voltage VDD1=Vt+Vdiode, the second supply voltage VDD2=0, the first control voltage, also called comparator output voltage, SWVDD1=0 and also the second control voltage, also called inverter output voltage, SWVDD2=0. The first switch SW1 is conducting and will try to force the voltage VDD=VDD1=Vt+Vdiode on the node OVDD. But because the control voltage SWDVDD2=0 and this is lower than VDD−Vt=VDD1−Vt=Vt 30 Vdiode−Vt, the second switch SW2 is also conducting and will try to force an output voltage VDD=0 on the node OVDD.
In the following, the voltage difference VDD1−Vdiode or the voltage difference VDD2−Vdiode is supposed to be higher than the constant voltage Vt. The stable state of the circuit will be determined. The comparator output 3 will be 0 if the first voltage VDD1 is higher than the second voltage VDD2 and the comparator output 3 will be the maximum voltage if the second voltage VDD2 is higher than the first voltage VDD1. The maximum voltage is the higher value of the two values VDD1−Vdiode or VDD2−Vdiode. The inverter INV, also supplied with the output voltage VDD, will produce a second control voltage SWVDD2, which is the maximum of VDD1−Vdiode and VDD2−Vdiode, if the first control voltage SWVDD1=0. The inverter INV will produce a second control voltage SWVDD2=0 if the first control voltage SWVDD1 is the maximum of VDD1−Vdiode and VDD2−Vdiode. The first control voltage SWVDD1 switches on the first switch SW1, this means the first switch SW1 is conducting, and the second control voltage SWVDD2 switches off the second switch SW2, this means the second switch SW2 is not conducting, when the first voltage VDD1 is higher than the second voltage VDD2. The control voltages SWVDD1 and SWVDD2 switch off the first switch SW1 and switch on the second switch SW2 when the second voltage VDD2 is higher than the first voltage VDD1. The output voltage VDD is then going from max (VDD1, VDD2)−Vdiode to max (VDD1, VDD2). Similarly, the control voltages SWVDD1 and SWVDD2 will either stay on 0 or go up to max (VDD1, VDD2).
This circuit has several drawbacks. It will not function, if the first voltage VDD1 and second voltage VDD2 are lower than Vt+Vdiode. If the first voltage VDD1 and the second voltage VDD2 are lower than Vt+Vdiode, there can be a high short circuit parasitic current.


A catheter assembly for assessing contact between the catheter assembly and tissue is disclosed. The assembly includes a catheter shaft and a pressure sensitive conductive composite member whose electrical resistance varies with pressure applied to the catheter assembly. The assembly also includes at least one measurement terminal to permit the measurement of changes in the electrical characteristics of the pressure sensitive conductive composite member. The assembly may optionally include a measurement device to measure resistance, impedance and/or other electrical characteristics. The assembly may utilize a reference electrode secured to the patient's tissue, which permits the measurement device to measure changes between the reference electrode and the at least one measurement terminal. Optionally, the assembly may include a conductive outer layer. Also disclosed are sensor assemblies, contact sensor, methods of contact sensing, and methods of manufacturing relating to the use of pressure sensitive conductive composites.

a. Field of the Invention
The present invention pertains generally to an electrophysiological device and method for providing energy to biological tissue and, more particularly, to a contact sensor that is capable of being using with an ablation apparatus to provide greater contact sensitivity.
b. Background Art
Sensing devices, including tissue sensing devices, have heretofore been provided, but not pressure sensitive conductive composite ("PSCC") based sensors (including, for example, quantum tunneling composites ("QTC") and other pressure-sensitive, conductive polymers).
Many medical procedures, including for example, creating lesions with electrical energy, rely on good contact between the medical device and the tissue. In some catheter applications, the point of electrode-tissue contact is typically 150 cm away from the point of application of force. This gives rise to functional and theoretical challenges associated with conventional devices, and thus, the ability to accurately assess tissue contact is increasingly important.
There is a need for contact sensing devices that provide greater contact sensitivity for control of medical treatments.
There is a need for improved sensor devices that provide greater contact sensitivity, especially in connection with RF ablation treatments.

Pressure-sensitive conductive composite contact sensor and method for contact sensing

St. Jude Medical, Atrial Fibrillation Division, Inc.


The disclosure relates to a transistor driver circuit with a plurality of transistors, each having source and drain regions formed in a substrate. At least first and second interconnect layers are formed on top of the substrate. A first plurality of contacts connect the source regions to one of the first or second interconnect layers. A second plurality of contacts connect the drain regions to the other of the first or second interconnect layers. The first and second interconnect layers cover a region above the substrate area in which the plurality of transistors reside so as to achieve a low ohmic result. The second interconnect layer has openings therein for one of the respective first or second plurality of contacts to pass therethrough and couple to the at least one first interconnect layer. Either the first or second interconnect layers can function as an input or output for the circuit.

1. Field of the Invention
The invention relates to semiconductor integrated circuit devices, and more particularly to large area transistors.
2. Related Art
A die (also called chip) is a small piece of silicon wafer, bounded by adjacent scribe lines in the horizontal and vertical directions, that contains the complete device being manufactured. An integrated circuit (also called an IC) comprises many interconnected circuit elements on a single die. Such interconnected circuit elements typically include semiconductor devices, such as transistors or diodes, and other devices, such as capacitors, resistors, and the like. Interconnects (also called wiring) are highly conductive material, usually aluminum, polycrystalline silicon (polysilicon), copper, or the like, that carry electrical signals to different parts of a die.
Signals generated on chip must be sent off chip in order to be coupled to other IC's or components. A common type of transistor used in IC's is a metal-oxide-silicon (MOS) field effect transistor (FET). Complementary metal-oxide-silicon (CMOS) transistor technology includes both p-type and n-type conductivity MOS transistors. Because today's IC's comprise millions of transistors, any one transistor is too small to output sufficient current to "drive" an off-chip (i.e., some other off-chip IC or component) or on-chip load.
So called "large driver" transistors comprise many MOS transistors connected together to provide sufficient output current to drive an off-chip or on-chip load. These drivers usually carry large current. Of course, larger current (I) means a larger voltage (V) drop (i.e., V=I*R; where R=resistance), and more power (P) dissipation (i.e., P=I2*R) across devices and/or interconnects. Larger voltage drop means smaller voltage swing available at the output. More power dissipation means lower efficiency as more power is lost due to heat, etc. Accordingly, larger voltage drop and/or more power dissipation lead to poor circuit performance.
Thus, what is desired is a transistor layout design with low ohmic characteristics.

Low ohmic layout technique for MOS transistors


A semiconductor laser device has a striped structure for injecting carriers and includes a first electrically-conductive cladding layer, an active layer, and a second electrically-conductive cladding layer that are formed on a substrate. A width of the stripe changes along a resonator direction, a difference between L1 and Lt is within 200 μm, and Rf<Rr, where L1 is a distance from a front end face to a position at which the width of the stripe is minimal, L is a length of a resonator of the semiconductor laser device, Rf is a reflectivity of the front end face, Rr is a reflectivity of a rear end face, and Lt is a distance expressed by L×Loge(Rf)/Loge(Rf×Rr). The saturation of a light emission efficiency is suppressed in a high power operation, allowing a stable fundamental transverse mode oscillation.

1. Field of the Invention
The present invention relates to a semiconductor laser device in which the saturation of a light emission efficiency in a high power operation is suppressed, and an optical pickup apparatus using the same.
2. Description of Related Art
A semiconductor laser device (in the following, also referred to as a semiconductor laser) is in wide use in various fields. For example, since an AlGaInP semiconductor laser emits red laser light in a wavelength band of 650 nm, it is used widely as a light source in the field of optical disk systems such as DVDs. As an exemplary structure of the semiconductor laser, a double hetero structure including an active layer and two cladding layers sandwiching the active layer, in which one of the cladding layers forms a mesa-shaped ridge is known (see JP 2001-196694 A, for example).
FIG. 10 shows an example of an AlGaInP semiconductor laser having such a structure. The composition ratio of each layer described below will be omitted. In the semiconductor laser shown in FIG. 10, an n-type GaAs buffer layer 102, an n-type GaInP buffer layer 103 and an n-type (AlGa)InP cladding layer 104 are stacked in this order on an n-type GaAs substrate 101 having a plane tilted by 15° in a [011] direction from a (100) plane as a principal plane. Furthermore, a strained-quantum well active layer 105, a p-type (AlGa)InP first cladding layer 106, a p-type (or undoped) GaInP etching stop layer 107, a p-type (AlGa)InP second cladding layer 108, a p-type GaInP intermediate layer 109 and a p-type GaAs cap layer 110 are stacked on the n-type (AlGa)InP cladding layer 104. Here, the p-type (AlGa)InP second cladding layer 108, the p-type GaInP intermediate layer 109 and the p-type GaAs cap layer 110 are formed as a ridge having a regular mesa shape on the p-type GaInP etching stop layer 107. Furthermore, an n-type GaAs current blocking layer 111 is formed on the p-type GaInP etching stop layer 107 and on the side surfaces of the ridge. A p-type GaAs contact layer 112 is stacked on the n-type GaAs current blocking layer 111 and the p-type GaAs cap layer 110 located in the upper portion of the ridge. The strained-quantum well active layer 105 includes an (AlGa)InP layer and a GaInP layer.
In the semiconductor laser shown in FIG. 10, an electric current injected from the p-type GaAs contact layer 112 is confined to the ridge portion alone by the n-type GaAs current blocking layer 111 and concentrates into the strained-quantum well active layer 105 near a bottom of the ridge. Thus, in spite of the amount of injected current being as small as several tens of mA, a population inversion state of carriers required for laser oscillation is achieved. At this time, the recombination of carriers generates light. Then, in a direction perpendicular to the strained-quantum well active layer 105, the light is confined by both of the n-type (AlGa)InP cladding layer 104 and the p-type (AlGa)InP first cladding layer 106, and in a direction parallel with the strained-quantum well active layer 105, the GaAs current blocking layer 111 absorbs the generated light, thereby performing light confinement. Consequently, when the gain obtained by the injected current exceeds the loss in a waveguide in the strained-quantum well active layer 105, laser oscillation occurs.
In such a semiconductor laser, it is desired that highest possible light output should be achieved for rewriting an optical disk at a high speed. For example, in order to achieve at least a quad-speed rewriting for a DVD optical disk, a light output as high as 100 mW or more is required. For obtaining such a high output power, it is necessary to prevent a COD (catastrophic optical damage), in which an end face of a semiconductor laser is melted down and broken by its own light output at the time of high power operation. The COD is prevented effectively by reducing a light density inside the end face of a resonator of the laser so as to suppress heat generation. For this purpose, coating a front end face of the semiconductor laser for extracting laser light with a dielectric such as SiO2, Al2O3 or amorphous Si so as to reduce its reflectivity is effective.
In general, the reflectivity of the end face of the resonator of AlGaInP and AlGaAs semiconductor lasers is about 30% when the end face is not coated. In this case, about 30% of the laser light is reflected by the resonator end face and fed back to the inside of the resonator, while about 70% of the laser light is extracted from the front end face. In contrast, when the front end face is coated with a dielectric film to have a reflectivity of 10%, 10% of the laser light is reflected by the resonator end face and fed back to the inside of the resonator, while 90% thereof is extracted from the front end face. In other words, in the case where the same light output is extracted from the front end face, when the reflectivity of the front end face is reduced to ⅓, it also is possible to reduce the light density of the resonator end face to ⅓. Accordingly, reducing the reflectivity of the front end face increases a COD level and thus is effective in obtaining a high-power laser. Furthermore, if the reflectivity of a rear end face, which is an opposite side of the resonator face from which the laser light is extracted, is set to be high, it is possible to enhance a light extraction efficiency from the front end face of the semiconductor laser. Therefore, in a general high-power semiconductor laser, an end face coating condition of reducing the reflectivity of the front end face and increasing that of the rear end face is used widely.
As described above, in order to obtain a high-power laser, the reduction in the reflectivity of the front end face and the increase in that of the rear end face are effective in improving the COD level and the light extraction efficiency. However, when the reflectivity of the front end face is reduced excessively, the laser light that is fed back inside the resonator decreases, raising an oscillation threshold current. Also, in the case of applying the semiconductor laser to an optical disk, when the reflectivity of the front end face is low, it becomes likely that reflected light returning from the optical disk may generate noise (noise induced by returning light). Accordingly, in a high-power laser, the front end face usually is coated such that its reflectivity is about 5% to 10% so as both to achieve a high light extraction efficiency and reduce the noise induced by returning light. Further, the rear end face is coated so as to achieve a highest possible reflectivity, namely, about 95% to 100% in general.
As described above, the front end face and the rear end face of the high-power laser have considerably different reflectivities. In such cases, the distribution of the intensity of light propagating through the active layer in a resonator direction is not front-rear symmetrical with respect to the resonator but front-rear asymmetrical as shown in FIG. 2 where the front end face side has a higher intensity in light intensity distribution. FIG. 2 shows a light distribution in the resonator direction of a device whose resonator length is 1100 μm, front end face reflectivity is 7% and rear end face reflectivity is 95%, as an example.
In this case, since a more intensive stimulated emission occurs on the front end face side having a higher light intensity than on the rear end face side, more electron-hole pairs have to be injected into the active layer on the front end face side than that on the rear end face side. Especially in a high power operation, the front end face side becomes short of the electron-hole pairs in the active layer, which may cause a saturation of a light emission efficiency. This saturation of the light emission efficiency may degrade temperature characteristics of a high-power laser of 200 to 300 mW or higher, thus posing a serious problem.

Semiconductor laser device and optical pickup apparatus using the same

Matsushita Electric Industrial Co., Ltd.


An electro-optical device includes semiconductor layers disposed between a first substrate and an electro-optical layer. The semiconductor layers are provided at positions corresponding to crossover regions of scanning lines and data lines. Island light shielding films are disposed between the second substrate and the electro-optical layer. The island light shielding films are isolated from each other and at least partially overlapping a corresponding one of the semiconductor layers in plan view.

1. Technical Field
The present invention relates to an electro-optical device having a pair of first substrate and second substrate, which are opposed to each other, and light shielding films; which are formed on the second substrate to shield light from entering corresponding transistors formed on the first substrate, and also relates to an electronic apparatus having the electro-optical device.
2. Related Art
A known electro-optical device, such as a light transmissive liquid crystal device is configured so that liquid crystal is interposed between a first substrate and a second substrate, which are formed of a glass substrate, a crystal substrate, a silicon substrate, or the like. Switching elements, such as thin-film transistors, and pixel electrodes are arranged on the first substrate in a matrix and an opposite electrode is arranged on the second substrate. Then, image display may be performed by changing the optical characteristics of the liquid crystal layer interposed between the first substrate and the second substrate on the basis of image signals.
In addition, an element substrate is the first substrate. The transistors are arranged on the element substrate. An opposite substrate is the second substrate. The opposite substrate is opposed to the element substrate. The element substrate and the opposite substrate are separately manufactured. The element substrate and the opposite substrate are, for example, formed so that a semiconductor thin film, an insulating thin film, and a conductive thin film, each of which has a predetermined pattern, are laminated on a crystal substrate. The element substrate and the opposite substrate each are formed by alternately performing a film deposition process and a photolithography process on each film in each of the layers.
Meanwhile, in the element substrate, a plurality of transistors that are provided in correspondence with pixel electrodes are formed at positions corresponding to crossover regions of data lines that supply image signals to the pixel electrodes and scanning lines that supply on signals to the transistors. The crossover regions are formed in a matrix in the display area of the liquid crystal device.
Here, when light enters known semiconductor layers in the transistors, specifically, channel regions of the semiconductor layers or regions of the semiconductor layers, which are electrically connected to pixel electrodes, the transistors malfunction and, therefore, there is a problem that display chrominance nonuniformity, cross-talk, and/or flicker occur in the liquid crystal device due to off leakage current and, in addition, defective display, such as a decrease in display contrast, occurs.
In consideration of the above problem, there is also a known liquid crystal device in which various thin films are laminated on an element substrate, and, of these thin films, light shielding films are provided in a layer formed below the semiconductor layers and cover the lower sides of the semiconductor layers in plan view, while other light shielding films are provided in a layer formed above the semiconductor layers and cover the upper sides of the semiconductor layers in plan view, thus making it possible to prevent light from entering the semiconductor layers.
For example, the scanning lines serve as light shielding films that cover the lower sides of the semiconductor layers in plan view, and the data lines and capacitor lines that hold voltages of the pixel electrodes serve as light shielding films that cover the upper sides of the semiconductor layers in plan view.
In addition, a known configuration in which, in the opposite substrate as well, in the display area, light shielding films are formed around each of the pixels in a stripe or in a matrix, which is described, for example, in Japanese Unexamined Patent Application Publication No. 2003-121879. The light shielding films, which are formed on the opposite substrate in a matrix, as described in JP-A-2003-121879, when the opposite substrate is bonded to the element substrate, are positioned so as to overlap the scanning lines and the data lines, which are formed on the element substrate in a matrix, as viewed in plan, so that the light shielding films, in cooperation with the light shielding films formed on the element substrate, prevent light from entering the transistors.
The opposite substrate, on which thin films have been laminated, is adsorbed by an adsorption head of a robot, or the like, and bonded through a seal material to the element substrate on which thin films have been laminated, with high accuracy of position.
Specifically, in order to shield light from entering the transistors by the light shielding films as well, the light shielding films, which are formed on the opposite substrate in a matrix, are bonded to the scanning lines and the data lines, which are formed on the element substrate in a matrix, in such a manner that the light shielding films overlap the scanning lines and the data lines with high positional accuracy.
However, it is difficult to bond the opposite substrate to the element substrate with completely high positional accuracy. In addition, even when the opposite substrate is bonded to the element substrate with high positional accuracy, when warpage, or the like, occurs in the element substrate or in the opposite substrate, the position of the opposite substrate may be deviated relative to the element substrate.
Furthermore, in recent years, in order to improve aperture ratio of each pixel, the widths of the light shielding films formed on each of the element substrate and the opposite substrate are made narrow to about 1.5 micrometers as compared to for example, about 2.5 to 3 micrometers in the existing art.
Thus, when the opposite substrate is bonded to the element substrate but the position of the opposite substrate is deviated relative to the element substrate, that is, when a positional deviation error of, for example, about plus or minus 0.5 to 0.7 occurs as a result of bonding of the substrates, the light shielding films formed on the opposite substrate in a matrix protrude into the light transmission regions in the display area. Thus, there has been a problem that the pixel aperture ratio varies among liquid crystal devices. In addition, there also has been a problem that the aperture ratio varies among pixels, in which some of the pixels ensure aperture ratios but other pixels have considerably decreased aperture ratios.

Electro-optical device and electronic apparatus


A method performed by a resolver in a core network of a wireless communication system, where the method comprise: receiving, from a requester in the core network, a request to resolve a provided identifier that is one of a subscription identifier and a pseudonym identifier serving in the core network as a pseudonym for the subscription identifier; and transmitting, to the requester as a response to the request, a resolved identifier that is the other of the subscription identifier and the pseudonym identifier.

A wireless communication system uses subscription identifiers to identify its subscribers (or associated universal subscriber identity modules, USIMs). The core network for example uses a long-term or permanent subscription identifier called an International Mobile Subscription Identifier (IMSI) as a stable and reliable identifier of subscribers. The system may however avoid transmitting the IMSI over-the-air as much as possible, in order to stop radio interface eavesdroppers from maliciously tracking a subscriber by observing the subscriber's identifier being transmitted in different locations. Instead, the system may use a temporary or short-term identifier such as a Globally Unique Temporary Identifier (GUTI) that is frequently refreshed to make tracking more difficult.
Further enhancing subscription identifier privacy in these and other contexts throughout the system nonetheless still proves challenging, in part because many network nodes and/or functions must still resort to using a long-term subscription identifier.

Identifiers in a wireless communication system


A double open-end claded-head wrench (10) that is particularly designed to loosen and tighten hexagon bolts and nuts that are made of a relatively soft metal such as aluminum. The wrench (10) is made of aluminum and includes a wrench handle (12), a first open-end head (28), and a second open-end head (56), a notch (50) that is cut into the corners of each of the wrenches hexagon angles, and a stainless steel head clad (80–86) that covers the upper and lower surfaces (14,16) of the first and second open end heads (28,56). The notches prevent the corners of the aluminum bolts or nuts from being worn by the gripping pressure applied by the heads of the wrench (10). The stainless steel claded heads (28,56) protect the wrench heads (28,56) from being worn from repeated uses of the wrench (10).

To conserve weight on many devices, such as on bicycles used by professional riders, aluminum bolts and nuts are used to adjust and/or secure many of the bicycle's components. When a conventional steel wrench is used to tighten or loosen aluminum bolts or nuts the interfacing pressure applied to the corners of the bolt or nut head can, after repeated uses, round the corners of the bolt or nut head. The rounded corners make it difficult for a wrench to acquire a secure grip on the bolt or nut head, which in turn, causes wrench slippage that further aggravates and increases the rounded corners on the head of the bolt and nut.
The above-described problem is solved by the double open-end closed-head wrench described herein.
A search of the prior art did not disclose any industry literature or patents that read directly on the claims of the instant invention.


A self-acting air bearing operable at very high speed in a non-vertical spin axis in a beam scanning optical system provides precise rotation of a rotable hologon disk. Pretreatment of the bearing surfaces with a residual boundary lubricant allows reliable operation over an extended series of start/stop cycles. The tilt of the bearing/disk assembly allows the construction of an optical system more compact than in conventional hologon beam scanning systems.

In the operation of a self-acting hydrodynamic bearing, a load may be supported by the pressure generated by fluid flow in the bearing gap by the relative motion of the bearing surfaces and viscosity of the fluid. Such bearings may be distinguished according to the composition of the fluid (air vs. oil, grease and the like) and the character of the bearing surface (either plain or grooved), and type of relative motion (journal or thrust).
Bearings which are designed to operate using fluids such as oil and grease require a greater gap than is necessary for an air bearing, the latter having a gap in the range of 2.5 to 5 micrometers. Oil- and grease-lubricated bearings experience a much larger drag torque on the bearing surfaces due to the much higher viscosity of the lubricant, which fills the gap as a thick film. The drag torque can be significant and the bearing starting torque can be undesireably high. The fluid is also subject to loss via leakage or evaporation, and to the detrimental effects of shearing stress and cavitation. As there is a significant risk of contamination of any optical assemblies that are proximate to the bearing, the bearing design must incorporate lubricant seals that are costly and complex, and which are themselves subject to failure.
Air bearings are therefore particularly suited to low-noise, high-speed, high-accuracy bearing applications, which makes them attractive for use in optical scanners In many instances it has been the availability of a gas bearing, which provides a high-accuracy, high-speed spin axis, that has broadened the scope of modern scanning applications. Self-acting air bearings are therefore the predominant bearing design in high-speed rotating polygon and hologon laser deflection systems.
Conventional self-acting air bearings are designed to be entirely free of the oil or grease associated with other hydrodynamic bearings. Unfortunately, a self-acting air bearing requires relative movement of the surfaces to generate pressure in the bearing gap. Some rubbing of the bearing surfaces takes place at start-up (wherein the bearing experiences "lift-off") and shut-down (wherein the bearing experiences "touch-down"). The bearing surfaces must therefore be manufactured from, or coated with, very hard materials such as nickel, ceramics, or cermets. Whereas these materials may be machined to the extremely high surface accuracies required for self-acting gas bearings, such materials are very expensive to fabricate and finish. For example, a ceramic piece may have a unit cost that is ten times the cost of a similarly-shaped piece that is fabricated from stainless steel.
Attempts to reduce starting friction and wear by the use of coatings with high sliding wear resistance, or boundary lubrication with fatty acids, have had limited success. Inserts do not provide the necessary surface accuracy over bearing life that the metallic or ceramic surfaces do. With respect to boundary lubrication, dispersion (creep) of the lubricant remains a problem. The conventional approach seeks to "wet" the bearing surface (i.e. establish a continuous oil film that will separate the bearing surfaces) without causing the lubricant to leave the bearing. Barrier films have been used to control the spread of a lubricant to nonbearing surfaces However, barrier films must be used with great care to avoid contamination of the bearing surfaces which renders them nonwettable and subject to wear.
When rotated, self-acting air bearings are subject to a complex instability phenomena. External vibration at specific frequencies, or poor balance, can stimulate these instabilities. The major factors contributing to instability are typically simplified to include mass/stiffness resonance and high-speed whirl. The former is the well-known type of resonance which occurs in every spring-mass system. However, in self-acting gas bearings, stiffness will change with speed and will not necessarily be linear with deflection. Bearings must be therefore be designed such that this resonance lies outside the frequency range of any likely external vibration and the speed range is below this resonance. If this is not possible, sufficient damping must be built in to limit the vibration amplitude. However, it is difficult to adequately dampen a hologon rotor assembly by means of shock mounting, because the hologon must rotate about its spin axis without the positional deviations associated with the flexure of a shock mount damping apparatus.
Air bearings operate on a very thin air film (5-10 .mu.m) between the bearing surfaces. The thinness and low damping of an air film make it necessary but extremely difficult to analyze the dynamic characteristics of the bearing for compliance, stability, and load carrying capacity at all of the possible excitation frequencies of the system. Nonetheless, the conventional remedy is to maintain close control of manufacturing tolerances, surface finishes, thermal and elastic distortions, alignment, and balancing.
Half-speed whirl is experienced when the average induced flow in a plain journal bearing running with no eccentricity occurs in the same direction as the rotation, but at half the rotational speed If the shaft is deflected from its central position, it will experience a centering force from the wedge effect and a backward torque from shear forces. These forces will cause the shaft to whirl in a direction opposite to the direction of rotation. When this whirl speed reaches the speed of flow around the bearing (i.e., half speed), there will be no relative flow through the gap and therefore the pressure forces will collapse. A bearing operating at twice the speed of its resonant frequency will tend to whirl at its resonant frequency, which is almost certain to cause bearing failure. If the bearing is to exceed this speed, it must be damped.
Fixed-geometry anti-whirl journal bearings have been proposed that achieve some degree of stability margin at the expense of reduced bearing stiffness (i.e., reduced load capacity) or increased friction. These designs include multi-lobes, Rayleigh steps or pockets, and axial grooves. Bearings with a build-in wedge effect, such as those having spiral grooving, are less effected by the instability induced by half-speed whirl, but are not immune to it. Other approaches include the use of attractive- or repulsive-magnet thrust bearings and tilting-pad radial air bearings, which nonetheless have unique drawbacks such as pad flutter, lockup, and pivot fretting.
All of the foregoing remedies increase the cost and complexity of the air bearing Moreover, no conventional approach has resulted in an inexpensive air bearing design that can withstand a series of start/stop cycles of more than about 20,000 cycles.
Accordingly, there remains, a distinct need for inexpensive, self-acting aerodynamic bearing for use in optical applications that can withstand a series of start/stop cycles well in excess of 20,000 cycles.

Self-acting air bearing for high speed laser scanner


A linear friction welding process provides two members to be joined together into a final product, where each of the members has a major outer surface, where one of the two members is a stub which is surrounded, at least in part, on its outer major surface by a collar. The stub is generally restrained without substantial restraining contact on its outer major surface by tooling, thereby eliminating the risk that tooling will cause physical or chemical damage to the final shape. Thereafter, pressure and relative movement are applied between said members to linear friction weld the members together. A collar comprises a major inner surface surrounding a portion of a major outer (lateral) surface of a member to be linear friction welded, and further comprises a radially outer surface which extends a surface to be interfaced of the member. The collar has an outer lateral surface which may be curved in order to prevent stress and cracking of the collar during linear friction welding. The inner and outer lateral collar surfaces may be generally parallel to each other, making the area of the outer radial surface of the collar small, so that less process input energy is needed to overcome the friction contributed by the collars, and so that the collars experience smaller loads during linear friction welding, making them easier to secure.

As known in the art, structures may be bonded together by means of linear friction welding. In such a process, a surface on one of the structures is contacted (interfaced) to a surface on the other structure. The interfacing surfaces typically have complimentary features, i.e. similar lengths and similar widths. The two parts are rubbed together, in a back and forth, somewhat linear type oscillatory manner. The axis of the oscillation is typically roughly aligned with the longitudinal (lengthwise) axis of the interface, i.e. end to end. As the parts are rubbed, compressive force is applied to place the interface under high pressure. At the interface, frictional heat is generated and material from each part changes to a molten or preferably to a plastic state. Some of this material flows out from between the parts (flash flow), resulting in gradual decrease in the thickness, i.e. the dimension in the direction in which pressure is applied (the dimension perpendicular to the interface) of the parts. When the process is terminated, flash flow ceases, and at the interface, the remaining plastic state material of each part cools and changes back to solid state, forming bonds therein and bonding the two parts together.
However, a problem exists with this process in that the bond is usually incomplete, i.e. defective, at the ends of the interface. The nature of the defect is that of a void, or notch. It occurs, in part, because the ends of the interface, roughly on the axis of oscillation, are alternatingly exposed to ambient during each oscillation cycle. While exposed, the end is not rubbed and therefore not frictionally heated. Thus, as a result of the alternating exposure, the ends are only alternatingly heated and the temperature of the ends does not get high enough to produce complete bonding.
Efforts have focused on developing processes which insure that the defect does not form within the outline of the final shape of the product. In the fabrication of original equipment, part geometries can be oversized so that the defects which form are located outside the outline of the final product. The defects are then removed as the product is machined down to its final shape. However, in repair situations, a damaged portion is removed, but the remaining portion is already at its final shape and dimension, and therefore, an oversized geometry is not a viable alternative.
One of the numerous applications for linear friction welding is that of attaching blades (airfoils) to a rotor and thereby forming an integrally bladed rotor (IBR). In such an application, a base surface on the blade is interfaced to a slightly elevated surface on the rotor. However, without preventative measures, the bond risks being defective at the blade edges, because the blade edges are situated at the ends of the interface, roughly on the oscillation axis, and therefore, the blade edges are alternatingly exposed to ambient and only alternatingly heated during oscillation. As a result, the edge temperature does not get high enough to produce complete, adequate bonding. Although the defect may not constitute a crack per se, it could mature into such during engine operation, and thus, its presence in an IBR is unacceptable.
In the prior art approach for preventing defects at the edges for IBR repairs, the damaged portion of a blade under repair is removed, e.g., by removing a longitudinal section, and flanges, or collars, are provided around the edges of the remaining portion. A pair of jaws grip the remaining (undamaged) portion, (having, as its final shape, the final shape of the repaired part), and its associated flange to secure each in place for linear friction welding. Although the undamaged portion is already joined to the IBR (as by linear friction welding), the undamaged portion is not rigid enough, side to side, and too highly cantilevered to undergo linear friction welding without the support of the jaws or similar tooling. Similar flanges and jaws are also provided to grip a replacement portion, also having as its final shape, the final shape of the repaired part, to linear friction weld it to the undamaged portion. The flanges around each portion prevent the blade edges of the other portion from being alternating exposed to ambient; thus sufficient heat is generated to achieve effective bonding. Defects may be formed in the flange region, because the flanges may be alternatingly exposed to ambient, but the flanges are subsequently machined away, along with such defect.
However, with this prior art approach, it is difficult for the jaws to securely hold the blades without causing damage to the finished shapes. First, the jaws generally cannot conform exactly to the shape of an individual blade, because the shapes of the blades vary somewhat from one another, due to normal manufacturing inaccuracies, and therefore, the jaws may cause physical damage to any particular blade when they grip it tightly. Further, high performance blades often comprise titanium, a relatively soft metal which is relatively easily marred on its surface. Such marring is highly undesirable because it adversely affects the aerodynamic performance of the blades. Still further, the jaws typically do not have the same material composition as the blades, and consequently, they can leave residual chemical deposits which thereby contaminate the surface finish. The surface finish is so critical in some applications that during fabrication, often times gloves are worn when handling the blades in order to prevent contamination of the blade surface finish.
In addition, the replacement portion is almost certain to be significantly damaged because it is solely supported by jaws gripping its finished airfoil. Unlike the remaining portion, the replacement portion is not integral to a larger structure, such as the blade disk, which provides support. Thus, the jaws grip the finished airfoil securely enough to withstand tens of thousands of pounds of pressure, and therefore, almost certainly inflicts deep imprints in the airfoil.
Another problem with prior art approaches is that the flanges tend to be large, contributing as much, or more, surface area to the interface, as that of the blade. While this may help prevent defects from forming in the blade edges, it requires excessive process input energy to overcome the friction contributed by the flanges alone, and subjects the flanges to tremendous loads during linear friction welding, making them extremely difficult to hold securely, especially in view of the fact that the same pair of jaws has to grip the both the flanges and the blade. Prior art flanges also have sharp, orthogonal edges, making the flanges more susceptible to stress and cracking during linear friction welding.


An optical amplifier operating at the 1.31 .mu.m wavelength for use in such applications as telecommunications, cable television, and computer systems. An optical fiber or other waveguide device is doped with both Tm.sup.3+ and Pr.sup.3+ ions. When pumped by a diode laser operating at a wavelength of 785 nm, energy is transferred from the Tm.sup.3+ ions to the Pr.sup.3+ ions, causing the Pr.sup.3+ ions to amplify at a wavelength of 1.31

The present invention generally relates to amplification of optical signals in optical fibers and other waveguide devices, and, more specifically, to amplification of light signals at a wavelength of 1.31 .mu.m.
Currently, optical fibers are being installed throughout the world for communication purposes. Where long distances must be traversed, as with trans-oceanic cables, it is a common problem to minimize the number of active amplifiers for the line. It is for this reason that most long distance telecommunication lines are operated at a wavelength of 1.55 .mu.m. At this wavelength, attenuation in signals in silica optical fiber is reduced, allowing for the use of fewer amplifiers per unit of distance. Erbium-doped optical fiber amplifiers which recently have been developed are sufficiently efficient and small enough for telecommunication applications. However, 1.55 .mu.m wavelength systems do suffer from relatively high signal dispersion, which results in temporal broadening of the light pulses.
In contrast, signal dispersion at 1.31 .mu.m wavelength in silica optical fibers is much improved, so that signals can be transmitted at the greatest temporal rate, making it also attractive for local area computer networks, subscriber cable television networks, and high-speed computing networks. Unfortunately, there has been little success in the development of practical 1.31 .mu.m wavelength optical amplifiers.
Because of the benefits of the 1.31 .mu.m wavelength, systems utilizing that wavelength have been installed by most telecommunication industries in the United States and in the United Kingdom. For amplification, these systems use a hybrid opto/electronic regenerator which decodes the optical information with sensors and uses electronics to command LEDs or lasers to retransmit the information down the next section of optical fiber. These regeneration systems are complex, bulky and costly, and have a much lower level of efficiency, reliability and capacity than is desired for modern communication systems.
Work on more practical optical amplifiers for the 1.31 .mu.m wavelength has been proceeding for some time without a great deal of success. Amplifiers for this wavelength have been demonstrated in the laboratory, but have not proven to be downscable to the size necessary for telecommunication applications. In doing this work, however, it has been recognized that proper doping of the optical fibers can tailor fibers to amplify at a desired length. For example, Praseodymium ions (Pr.sup.+3) have been used with limited success to dope standard ZBLAN.RTM. (fluoro-zirconate) fiber glass. The major problem with this fiber is that it must be pumped at a wavelength of 1.02 .mu.m, a wavelength for which no economically feasible high-power diode laser currently exists.
Other work has shown that Ytterbium ions (Yb.sup.3+) can be added as a codopant with Pr.sup.3+ to provide energy transfer with Pr.sup.3+. This system can be pumped at 890 nm, a reasonable diode laser wavelength, and energy is transferred to the Pr.sup.3+ ions to provide gain at 1.31 .mu.m. Regrettably, this system has not proven to be as successful as hoped because of inefficiency of the energy transfer between the dopants, and because of problems with the energy absorption of the Yb.sup.3+ ions at this wavelength.
It is therefore an object of the present invention to provide practical apparatus for the amplification of signals at the 1.31 .mu.m wavelength.
It is another object of the present invention to provide a 1.31 .mu.m amplification system which can be pumped by readily available lasers.
Additional objects, advantages and novel features of the invention will be set forth in part in the description which follows, and in part will become apparent to those skilled in the art upon examination of the following or may be learned by practice of the invention. The objects and advantages o the invention may be realized and attained by means of the instrumentalities and combinations particularly pointed out in the appended claims.

Optical amplification at the 1.31 wavelength

The United States of America as represented by the United States Department of Energy


The invention relates to a regulated DC power supply circuit comprising a full wave rectification stage for rectifying an AC input and a regulating stage for regulating an output voltage from the rectification stage. The regulating stage has a primary voltage regulating circuit and a secondary voltage regulating circuit. The primary voltage regulating circuit includes a series pass element, such as a MOSFET device, connected to operate continuously in source-follower mode. A primary voltage reference element, such as a zener diode, provides a gate reference for the series pass element. The secondary voltage regulating circuit is cascaded to the primary voltage regulating circuit in a voltage sharing configuration. The power supply circuit is therefore capable of handling input voltages over 1 kV, which exceed the maximum voltage rating of the MOSFET device. The invention extends to a DC voltage regulator, which includes the regulating stage without the rectification stage.

This invention relates to a regulated power supply circuit, as well as to a voltage regulator which is employed in such a circuit.
In the past, a number of problems have been associated with regulated power supply circuits which have to cope with wide input voltage ranges. At voltages in excess of 1 kV, only relatively low biasing currents can be fed to the power supply in order to avoid high power dissipation. The standard zener transistor configuration requires excessive zener biasing current which results in a high power dissipation. High voltage transistors exhibit relatively low current gains, and the basic current drawn by such transistors loads any reference and may drastically affect regulation with dynamic output loads.
At present, there exists no single commercially available transistor capable of efficiently providing a low voltage regulated supply from an unregulated input exceeding 1 kV.


A computer-implemented system for managing the underwriting, quoting and binding by an insurance company of an excess casualty insurance policy for an insured having a primary insurance policy with a primary insurance limit amount. The system selects and stores at least one standard industrial classification code ("SIC code") associated with the insured and a primary carrier name or multiple carriers associated with the primary insurance policy. A plurality of SIC code records corresponding to a plurality of SIC codes are stored in a database. Each of the SIC code records are linked to underwriting guidelines established and filed by the insurance carrier. These criteria include guidelines related to minimum premiums, hazard rating, underwriting authority, and referral criteria. Primary insurance carrier public bureau rating records are also stored in the database. Each of the primary insurance carrier public bureau rating records includes a field for storing a rating code representing a financial stability rating associated with a primary insurance carrier. The system displays for the insurance carrier underwriter a plurality of candidate risk modifiers associated with the retrieved SIC code record, and for documenting and storing a selected risk modifier code and related underwriting criteria associated with the policy. The system develops the quotation using a detailed description of the insured's operation, the minimum premium amount information, the selected hazard code, the selected risk modifier code, primary insurance limits, and one or more attachment points.

When an entity that has purchased a primary insurance policy wishes to insure against risks that may exceed the limits of its primary (or underlying) insurance policy, the entity may look to purchase excess insurance. Thus, the purpose of an excess insurance policy is to cover an insured in the event that the insured incurs liability that is in excess of the coverage limits of its primary insurance policy. Typically, one or more layers of excess insurance policies may be used to supplement a particular primary insurance policy. For example, an insured may purchase a primary insurance policy with a coverage limit of $10 million, a first excess insurance policy which would cover losses in excess of $10 million up to a further limit of $20 million, and a second excess policy which would cover losses in excess of $20 million up to a further limit of $30 million. The first excess insurance policy is said to have an "attachment point" of $10 million, because the coverage offered by the policy will not be invoked unless the insured's liability exceeds $10 million. Similarly, the second excess insurance policy has an "attachment point" of $20 million, because the coverage offered by that policy will not be invoked unless the insured's liability exceeds $20 million. When there are multiple excess insurance policies, each of the policies will typically be written by a different insurance company, and will be reinsured through other insurance companies.
Companies often purchase excess insurance to cover losses for remote events that may not occur for many years into the future. For example, a drug company may purchase such insurance to cover unknown adverse effects which may only manifest themselves in a patient many years after the patient has taken the drug company's product. Since excess policies involve risks that may be 20-30 years into the future, it is important for all relevant information pertaining to the excess policy to be properly documented and permanently stored at the time that the policy is initially issued.
Insurance companies that write excess insurance often receive submissions through licensed insurance wholesalers, brokers and retail producers. When such an insurance business producer wishes to compete for an excess policy, it is important for the insurance company to be able to provide the business producer with a quote which accurately reflects the characteristics of the risk, and, if necessary, to audit any information provided by the business producer before any quote is issued.
It is therefore an object of the present invention to provide a system for quoting, binding and later issuing an excess insurance contract in which all relevant information pertaining to the risk is properly documented and permanently stored.
It is a further object of the present invention to provide a system for quoting excess insurance which requires the quoted premium to accurately reflect the risks associated with a policy, and which permits the auditing of the risk characteristics, rating and pricing methodology associated with a quote before it is issued.
These and other objects and advantages of the invention will become more fully apparent from the description and claims which follow or may be learned by the practice of the invention.

System for electronically managing and documenting the underwriting of an excess casualty insurance policy


A wagon for use in hospital environments includes a bracket such that an I.V. stand may be quickly connected to the wagon. In this way, the I.V,. stand and the wagon can be moved as a unit for transport of patients. The inventive structure of the bracket ensures that the I.V. stand is held closely to the wagon, such that it requires a relatively small lateral space, and such that it is guided against lateral tipping.

This application in general relates to a bracket for attaching an I.V. stand to a hospital transport device.
In modern hospital environments patients are transported on any of several types of transport devices. In particular, hospital tables and wheelchairs are often utilized to transport patients. It is known with such devices to use various types of attachment members which will carry an I.V. stand along with the patient as the patient is transported on the device. A main factor in the development of such attachment members is the reduction of necessary hospital personnel to transport the patient. In the absence of such attachment members, a first hospital employee must push the patient in the device, while a second employee moves the I.V. stand.
The prior art systems which have accomplished this goal have been somewhat deficient. In particular, these attachment members have generally attached the I.V. stand away from the transport device such that the I.V. stand moves either behind, or to the side of the patient transport device. With such systems, an undesirably large amount of space is required. Further, the I.V. stand is not closely guided on the patient transport device, and there is the danger that it may tip.
More recently, wagons have been utilized to transport young patients in hospital environments. It is believed that the wagon presents a less intimidating image to a young patient. It has not been known to attach I.V. stands for transport with wagons. This is particularly undesirable. Having two hospital employees travelling with a patient who is being pulled in a wagon by a first employee, and requiring a second employee to walk alongside the wagon pushing an I.V. stand could be intimidating for a young patient.

Bracket for attachment of I.V. stand to a hospital transport device


A semiconductor device includes a semiconductor substrate that includes first and second regions; first, second, and third insulating layers; a capacitor dielectric layer that includes first and second dielectric layers; a gate insulating layer formed on the first and second regions; a gate formed on the gate insulating layer of the second region; a first capacitor electrode formed on the capacitor dielectric layer; and impurity regions formed in the semiconductor substrate on sides of the gate. The first and second regions include first and second trenches, respectively. The third insulating layer is formed on the second insulating layer, which is formed on the first insulating layer, which is formed on an inner surface of the second trench. The second dielectric layer is formed on the first dielectric layer, which is formed on an inner surface of the first trench.

1. Field
Example embodiments relate to semiconductor devices. Also, example embodiments relate to semiconductor devices including a capacitor in a shallow trench isolation (STI) structure, and methods of fabricating the semiconductor devices.
2. Description of the Related Art
Generally, a capacitor of a semiconductor device is formed to improve the protection of the semiconductor device against electromagnetic interference (EMI) and to facilitate voltage stabilization. The capacitor may be a depletion NMOS capacitor, a polysilicon-insulator-polysilicon (PIP) capacitor, a metal-insulator-metal (MIM) capacitor, and the like. In order to integrate the capacitor in the semiconductor device for EMI improvement and voltage stabilization, a separate active region for the capacitor may be required. Thus, scaling down the chip size is difficult. Furthermore, since an additional process of forming the capacitor is necessary, the manufacturing process of the semiconductor device becomes complicated.

Methods of fabricating semiconductor devices


The present invention relates to a system with active learning and execution of user's preference functionalities for use in a garment. The present system includes a sensor module, an optional user input panel and/or interface, a printed circuit board, a power source and an output. In an event that a user of the present system voluntarily changes the output setting during the operation of the system, the system performs an active learning action to execute the output setting initiated by the user over a passive learning action triggered by a change in sensor data with respect to the changing environment. In other event, the present system performs passive learning action with respect to the changing environment and also any comparative data from similar user of a particular instance. The present invention also relates to a power management unit and how to use the same in a garment.

There exists a number of heating garments on the market. They operate with users' input from knobs/button, and/or from user's input via connected mobile electronic devices. One of the disadvantages of such devices is that users need to keep on accessing the buttons or their mobile phone when using such clothes in order to manually configure temperature settings, which may not be convenient since most of the time, such clothes have been designed for outdoor activities (sport or professional use cases). For instance, a user skiing may find it difficult to access the controlling knobs/buttons on his clothes while skiing, or even more impractical to have to constantly input the commands via an application on his smartphone. Therefore, there is an unmet need for a smart garment which incorporates a system that can learn and execute a user's preferences and automatically respond to the internal and/or external changes without user intervention.
In addition, smart clothes currently on the market mostly use an integrated or specific dedicated power source (battery/power bank). The main reason is that non-specific power banks from the market would turn to off mode when idle for a short period, hence requiring the user to re-start them before they can operate their electric textile. The power bank may also go idle during usage cycles, such as heating cycles: once a set temperature is reached, the current is no longer drawn until the temperature has dropped to a set low level.
One solution is to send a pulse signal into heating elements at regular intervals, based on current detection and/or temperature detection. One such system has already been described in the PCT patent application publication number WO2017000597A1. However, it still remains some rooms for improvement. A new power management unit for use in a smart textile is therefore needed

System and method of machine learning and autonomous execution on user preferences for use in garments


A machine for stacking articles such as wooden pallets comprises a frame for supporting a carriage assembly that can be raised and lowered under control of a motor and where the carriage assembly supports an article grasping machine that is slidably mounted on the carriage assembly allowing horizontal movement of the article grasping assembly relative to the carriage. When using the machine to stack wooden pallets, a pallet may be picked up at a first location and elevated and translated so as to overlay a top pallet on a stack of pallets before the one being carried is released.

I. Field of the Invention
This invention relates generally to materials handling apparatus, and more particularly to a machine for either stacking or unstacking articles such as wooden pallets and the like.
II. Discussion of the Prior Art
Machinery exists for automating the manufacture of wooden pallets on which products are placed when shipping by truck or rail. In this regard, reference is made to my co-pending application Ser. No. 08/695,936, filed Aug. 12, 1996, which describes a machine for facilitating the assembly and nailing of lumber items when fabricating pallets. Machines are also known for taking the finished pallets from a conveyor and thereafter arranging a plurality of such pallets in a vertical stack. Here, reference is made to the Model 505 pallet stacking machine manufactured by applicant's assignee. In this machine, new pallets are added to the stack by elevating an entire stack and inserting the next pallet at the bottom of the stack and then again elevating the stack preparatory to receiving the next pallet to be added.
Stated otherwise, a new pallet to be added to the stack enters below the stack being built and it is raised to the bottom of the stack. Once the height of the stack reaches a predetermined number of pallets, it must be removed from the stacking machine. To accomplish this, it is necessary to include as a part of the machine a set of outfeed rollers for holding the finished stack at a location that is displaced from the stacking machine so that a new stack can be started. The completed stack now on the outfeed rollers now must be removed therefrom and lowered to the floor, requiring a fork truck and an operator.
Not only does inclusion of the outfeed rollers and the need for a forklift and driver necessarily raise the cost of production of pallets but also, because the lifting mechanism employed must be sufficiently robust to lift an entire stack which may easily weight 1200 lbs., the pneumatic or hydraulic system employed necessarily has to be sufficiently large to handle the load, which too adds to the cost.
Another problem that often arises when prior art pallet stacking machines are used occurs if an irregularly shaped pallet enters the stack. If an uneven pallet is added to the bottom of the stack, it can tip the entire stack that is placed on it. This may require the operator to summon a forklift operator to lift the portion of the stack above the irregular pallet so that the irregular one can be removed from the bottom of the stack.
The present invention obviates all of the foregoing problems by providing a pallet stacking machine that enters a new pallet to a stack by adding it to the top thereof rather than lifting the stack and inserting the new pallet below the others. By using this approach, a stack can be built directly on the ground, which allows an inexpensive pallet jack instead of a forklift to move a completed stack of pallets away from the stacking machine so that a new stack can be created.
It should also be apparent that a pallet stacking machine which adds the newest pallet to the top of the stack only requires the lifting of one pallet at a time. Accordingly, the cost of lifting mechanism and the power supply, whether pneumatic or hydraulic, is reduced. These features necessarily reduce the overall cost of pallet production.

Viking Engineering & Development Incorporated


An address switch circuit receives a row address signal supplied to a first address terminal group and a column address signal supplied to a second address terminal group. Further, the address switch circuit receives the row address signal supplied to the second address terminal group and thereafter receives the column address signal supplied to the second address terminal group and supplies the received row address signal and the received column address signal to the row decoder and the column decoder during a second operation mode. The number of semiconductor memories that are tested at once can be increased by executing an operation test of the semiconductor memories in the second operation mode. In addition, it becomes possible to test a semiconductor memory using test assets for other semiconductor memories. Consequently, the test efficiency can be improved, and the test cost can be reduced.

1. Field
The application relates to a semiconductor memory which receives a row address signal and a column address signal to operate.
2. Description of the Related Art
A semiconductor memory such as a pseudo SRAM has DRAM memory cells (dynamic memory cells) and operates as an SRAM by internally performing a refresh operation of the memory cells automatically. The pseudo SRAM performs the refresh operation without being recognized by a controller such as CPU during a period in which a read operation or a write operation is not performed. The refresh operation is performed using an address signal generated by an internal address counter in response to an internal refresh request which occurs periodically in the pseudo SRAM (for example, Japanese Laid-open Patent Publication No. H01-125796).
The memory core of a pseudo SRAM has the same structure as the memory core of a DRAM, and the memory core operates as a DRAM. Accordingly, when DRAMs and pseudo SRAMs are manufactured, the test efficiency improves if the same program as that for the DRAMs can be used for testing the pseudo SRAMs. Particularly, a test pattern for writing a predetermined data pattern in memory cells arranged in a matrix form is designed depending on the layout structure of a memory core. Therefore, it is wasteful to design test patterns respectively for pseudo SRAMs and DRAMs having memory cores of the same structure.
However, in a pseudo SRAM, a row address signal and a column address signal are supplied simultaneously via terminals different from each other together with an access command (address non-multiplex type). On the other hand, in a DRAM, a row address signal and a column address signal are supplied sequentially from a common address terminal (address multiplex type). Therefore, conventionally, it has not been possible to use a test pattern for a DRAM to test a pseudo SRAM.

Semiconductor memory, test method of semiconductor memory and system


A network device computes a set of maximally redundant trees from an ingress network device to a plurality of egress network devices based on a network graph, in which each of the set of maximally redundant trees comprises a spanning tree to the plurality of egress network devices rooted at the network device. The network device computes the maximally redundant trees such that each of the links along each of the set of maximally redundant trees satisfies a specified traffic-engineering constraint. The ingress network device establishes a plurality of point to multipoint (P2MP) label switched paths (LSPs) from the network device as an ingress network device to the plurality of egress network devices along the set of maximally redundant trees, wherein each of the P2MP LSPs corresponds to a different one of the maximally redundant trees.

The term "link" is often used to refer to the connection between two devices on a computer network. The link may be a physical medium, such as a copper wire, a coaxial cable, any of a host of different fiber optic lines or a wireless connection. In addition, network devices may define "virtual" or "logical" links, and map the virtual links to the physical links. As networks grow in size and complexity, the traffic on any given link may approach a maximum bandwidth capacity for the link, thereby leading to congestion and loss.
Multi-protocol Label Switching (MPLS) is a mechanism used to engineer traffic patterns within Internet Protocol (IP) networks. By utilizing MPLS, a source device can request a path through a network, i.e., a Label Switched Path (LSP). An LSP defines a distinct path through the network to carry packets from the source device to a destination device. A short label associated with a particular LSP is affixed to packets that travel through the network via the LSP. Routers along the path cooperatively perform MPLS operations to forward the MPLS packets along the established path. LSPs may be used for a variety of traffic engineering purposes including bandwidth management and quality of service (QoS).
A variety of protocols exist for establishing LSPs. For example, one such protocol is the label distribution protocol (LDP). Procedures for LDP by which label switching routers (LSRs) distribute labels to support MPLS forwarding along normally routed paths are described in L. Anderson, "LDP Specification," RFC 3036, Internet Engineering Task Force (IETF), January 2001, the entire contents of which are incorporated by reference herein. Another type of protocol is a resource reservation protocol, such as the Resource ReserVation Protocol with Traffic Engineering extensions (RSVP-TE). RSVP-TE uses constraint information, such as bandwidth availability, to compute and establish LSPs within a network. RSVP-TE may use bandwidth availability information accumulated by a link-state interior routing protocol, such as the Intermediate System-Intermediate System (IS-IS) protocol or the Open Shortest Path First (OSPF) protocol. RSVP-TE establishes LSPs that follow a single path from an ingress device to an egress device, and all network traffic sent on the LSP must follow exactly that single path. The use of RSVP-TE, including extensions to establish LSPs in MPLS, are described in D. Awduche, "RSVP-TE: Extensions to RSVP for LSP Tunnels," RFC 3209, IETF, December 2001, the entire contents of which are incorporated by reference herein.
In some cases, RSVP-TE can be used to establish a point-to-multipoint (P2MP) LSP that can be used for sending traffic across a network from a single ingress to multiple egress routers. The use of RSVP-TE for establishing P2MP LSPs is described in R. Aggarwal, "Extensions to RSVP-TE for P2MP TE LSPs," RFC 4875, May 2007, the entire contents of which are incorporated by reference herein. A P2MP LSP is comprised of multiple source-to-leaf (S2L) sub-LSPs. These S2L sub-LSPs are set up between the ingress and egress LSRs and are appropriately combined by the branch LSRs using RSVP semantics to result in a P2MP TE LSP.

This patent is subject to a terminal disclaimer.

Constrained maximally redundant trees for point-to-multipoint LSPs