A semiconductor manufacturing apparatus including a heating device; a reaction tube disposed within the heating device, the reaction tube having a gas inlet portion and an exhaust portion parted from each other by a predetermined distance in the longitudinal direction of the reaction tube; and a plurality of gas feed pipes extending along a side wall of the reaction tube from the exhaust portion side to the gas inlet portion, the plurality of gas feed pipes being parted from each other. The reaction gas is provided through the plurality of gas feed pipes into the reaction tube, thereby providing an improved uniform temperature distribution within the reaction tube and resulting in an improved uniform film thickness of the oxide film formed on the surface of the semiconductor wafer.

1. Field of the Invention
The present invention relates to a semiconductor manufacturing apparatus, and particularly to a semiconductor manufacturing apparatus in which various processes such as oxidation, diffusion, and thermal treatment are performed for semiconductor wafers.
2. Description of the Related Art
The manufacture of semiconductors includes a process of forming a thermal oxidation film on the surface of a silicon wafer. This process is performed using, for example, a vertical-type semiconductor manufacturing apparatus shown in FIGS. 1A and 1B.
FIG. 1A shows a cross-section of the conventional semiconductor manufacturing apparatus 1. FIG. 1B shows a cross-section taken along a line X1--X1 of FIG. 1A.
As shown in FIGS. 1A and 1B, in the semiconductor manufacturing apparatus 1, a liner tube 230 is disposed within a hollow heater 220, and a reaction tube 100 is disposed within the liner tube 230. The liner tube 230 is formed of a material having a large thermal capacity and its function is to provide a uniform temperature distribution within a furnace. The reaction tube 100 has a reaction tube body 10 having a circular cross-section and a single gas feed pipe 20. An upper gas feed pipe 40 is disposed on a ceiling plate 14 of the reaction tube body 10. The upper gas feed pipe 40 and the ceiling plate 14 define a shower chamber 42. A portion of the ceiling plate 14 located within the shower chamber 42 serves as a gas shower plate 30 having a plurality of gas diffusion holes 32. The shower chamber 42 communicates with the interior of the reaction tube body 10 through the gas shower plate 30. The gas feed pipe 20 is vertically provided along a generatrix of the reaction tube body 10 and on the outer surface of the reaction tube body 10. A gas inlet portion 21 is provided at the lower end portion (upstream-side end portion) of the gas feed pipe 20, and the upper end portion (downstream-side end portion) thereof communicates with the shower chamber 42 located at the top portion of the reaction tube body 10. An exhaust pipe 50 is provided adjacent to the lower end of the reaction tube body 10 such that it communicates with the reaction tube body 10. The gas inlet portion 21 is connected to a reaction gas source (not shown), and the exhaust pipe 50 is connected to an exhauster (not shown).
A boat 210 is raised and lowered by a boat elevator (not shown), thereby introducing the boat 210 into the reaction tube body 10 or removing the boat 210 therefrom. The boat 210 stands on a boat cap 60, which is provided on a furnace cover 62. A flange 12 is provided along the periphery of the reaction tube body 10 at the lowermost end thereof. An O-ring 64 is interposed between the flange 12 and the furnace cover 62, thereby maintaining the reaction tube body 10 in an airtight state.
The boat 210 has four boat support shafts 212, on which a plurality of wafers 200 are loaded in a horizontal posture such that one wafer is located above another. Each wafer 200 loaded in the boat 210 undergoes oxidation to form an oxide film on the surface thereof.
For oxidation of the wafers 200, while the interior of the furnace and the wafers 200 are heated to and maintained at an oxidation temperature, the oxygen gas is fed to the shower chamber 42 through the gas feed pipe 20 and then diffused into the reaction tube body 10 through the gas diffusion holes 32 formed in the gas shower plate 30. The oxygen gas reacts with the wafers 200 to form oxide films on the wafer surfaces. The gas after reaction is discharged through the exhaust pipe 50.
The length of the reaction gas feed pipe 20 is substantially identical to that of the portion of the reaction tube body 10 located within the heater 220 and within the liner tube 230. Conceptually, oxygen gas is heated in the following manner. Oxygen gas introduced from the gas inlet portion 21 at around room temperature is heated while passing through the gas feed pipe 20. When the oxygen gas reaches the shower chamber 42, it reaches a temperature substantially equal to that of the inside of the reaction tube body 10 and the wafers 200 contained therein. The thus heated oxygen gas enters the reaction tube body 10.
However, since the oxygen gas fed from the gas inlet portion 21 has a temperature close to the room temperature, the temperature difference between the gas feed pipe 20 and the interior of the furnace increases toward the upstream-side portion of the gas feed pipe 20 and the amount of heat absorbed from the interior of the furnace increases accordingly. Hence, when the oxygen gas is fed through a single gas feed pipe 20, the upstream-side portion of the gas feed pipe 20 causes cooling in the portions of the wafers 200 located near the gas feed pipe 20. Particularly, this causes nonuniform temperature distribution over the wafer surface. As a result, since the wafer temperature affects the growth rate of oxide film, oxide film is formed having a nonuniform thickness over the wafer surface.


A process for production of malic acid includes obtaining a feed that includes one or more of crude maleic anhydride, pure maleic anhydride, crude maleic acid, crude fumaric acid, pure maleic acid, pure fumaric acid, vent gas scrubber solutions from production of maleic anhydride, and vent gas scrubber solutions from production of phthalic anhydride. The feed is passed in a tubular reactor assembly to obtain a first product stream, which includes unreacted feed and malic acid. The feed is made to undergo hydration reaction in the tubular reactor assembly for a first predetermined time period, and further hydration of the first product stream is caused in a stirred tank reactor assembly for a second predetermined time period to obtain a final product stream, which includes the malic acid.

Malic acid is traditionally manufactured by the hydration of maleic acid, which is prepared by the dissolution of maleic anhydride in demineralized water or using a mixture of maleic acid and fumaric acid under conditions of high pressure and high temperature. The time taken to attain equilibrium, i.e., formation of an equilibrium mixture of malic acid, fumaric acid, and trace amounts of unreacted maleic acid, which is considered as the time to reach completion of the reaction for a given quantity of maleic acid or its isomer fumaric acid or a mixture thereof, varies from 4 to 8 hours.
Catalysts have been found to increase the productivity of malic acid in the aqueous hydration of maleic acid. In a typical hydration reaction, maleic acid is hydrated in the presence of various catalysts including sulfuric acid.
US3379756 describes a process for the synthesis of malic acid from maleic acid, fumaric acid, and mixtures thereof in an aqueous reaction mixture at elevated temperature and pressure wherein the process is performed in a reactor zone whose surfaces that are exposed to the reaction mixture consist of at least one material from the group of titanium, zirconium, tantalum, and alloys containing at least one of the said material.
U.S. Pat. No. 5,210,295 discloses a process for the hydration of an acid selected from maleic acid, fumaric acid and others, where the high temperature reaction is done in the presence of sodium ions in specified molar ratios.
U.S. Pat. No. 3,379,757 discloses a process for the manufacture of malic acid from aqueous solutions of maleic acid resulting from the vapor phase catalytic oxidation of an organic compound such as benzene comprising ageing the resulting maleic acid solution in the presence of air, filtering the aged solution and heating the filtrate in a closed system under super atmospheric pressure to convert the maleic acid to malic acid. This ageing process is carried in a rubber lined steel tower.
IN201621024815 discloses a process for preparation of malic acid in titanium tubular reactors. It further discloses that the tubular reactor of a particular design made with specific corrosion-resistant material like Titanium, with a high pressure circulating pump, prevents plugging and promotes high speed conversion.
However, the conventional methods of production of malic acid have several disadvantages. For example, very high temperatures and pressures are required for the reaction, it takes a long time for the reaction to reach equilibrium, the reaction products are corrosive and poisonous leading to corrosion of reactor vessels, and additional processes are required for removing contaminants from the products, leading to higher operating costs. Large reactor volumes are required at industrial scale Malic acid production by conventional methods.

Production of malic acid using tubular and stirred tank reactors


The process of preparing ansa-metallocene complexes in high yield by reacting a metal leaving group complex with an aluminum ansa-bis-cyclopentadienyl compound.

This invention relates to the field, now well established, of use of ansa-metallocenes as catalysts. They are particularly useful as catalysts for the polymerization of ethylene and alpha olefins such as propylene.
Conventional heterogeneous catalysts such as Ziegler-Natta systems have a variety of active sites, only some of which are stereo-specific. Obtaining a polymer with specific properties can involve a considerable amount of trial and error in order to find the best combination of catalyst, co-catalyst and stereo-regulator. In contrast, however, the active polymerization site in a metallocene catalyst is well defined, and can be modified in a straightforward manner via modification of the cyclopentadienyl ligands, enabling the structure of the polymer to be controlled with far greater precision.
A simple metallocene catalyst for polymerizing ethylene is (C.sub.5 H.sub.5).sub.2 ZrCl.sub.2 which consists of a zirconium atom bound to two chlorine atoms and two cyclopentadienyl rings, and which is activated by co-catalysts such as methylaluminoxane (MAO). During the 1980's, ansa or bridged metallocenes, in which the cyclopentadienyl rings are linked by a chemical bridge, were found to be particularly useful for the polymerization of olefins. In particular, ansa-metallocene complexes, when used in combination with a co-catalyst such as methylaluminoxane (MAO), polymerize propylene to highly isotactic polypropylene, highly syndiotactic polypropylene, or atactic polypropylene, depending on the structure of the ansa-metallocene used.
As is well known, isotactic polymers have each pendant group attached to the backbone in the same orientation, whereas in syndiotactic polymers, these groups alternate in their orientations and atactic polymers have a random arrangement of the groups along the backbone. Since the stereochemistry of the polymer has a great effect on its properties, it is desirable to control this feature. Chiral, C.sub.2 -symmetric ansa-metallocenes produce isotactic polypropylene.
While the greatest area of potential use for ansa-metallocene catalysts currently is for polymerization of olefins, such as ethylene and propylene, they also have significant uses as catalysts or catalyst precursors for other reactions where stereo-selectivity is important.
The utility of ansa-metallocene complexes as catalysts for olefin polymerization and other reactions has created a high demand for a practical synthesis of ansa-metallocene compounds.
In spite of this demand, current procedures for the synthesis of Group 4 (Ti,Zr,Hf) ansa-metallocenes based on the use of ansa-bis-cyclopentadienyl dianion reagents are hampered by low yields and tedious isomer separation and purification steps. Some of these problems have been discussed in Ellis, W. W.; Hollis, T. K.; Odenkirk, W., Whelan, J.; Ostrander, R.; Rheingold, A. L.; Bosnich, B. Organometallics 1993, 12, 4391. In particular, the synthesis of chiral C.sub.2 symmetric ansa-metallocenes typically produces mixtures of desired rac (racemic) and undesired meso isomers. A typical synthesis of an ansa-metallocene complex is shown in equation 1 below: ##STR1##
This equation is typical of the process as shown in the art. See for example Spaleck, W.; Kuber, F., Winter, A.; Rohrman, J.; Bachmann, B.; Antberg, M.; Dolle, V.; Paulus, E. F. Organometallics 1994, 13, 954. Stehling, U.; Diebold, J.; Kirsten, R.; Roll, W.; Brintzinger, H. H.; Jungling, S.; Mulhaupt, R.; Langhauser, F. Organometallics 1994, 13, 964. Halterman, R. L. Chem. Rev. 1992, 92, 965. See also, for example, U.S. Pat. No. 5,145,819, U.S. Pat. No. 5,268,495, and EPA 0-530-908-A1.
By way of further example, an important chiral Group 4 ansa-metallocene is rac-(EBI)ZrCl.sub.2 (EBI=ethylene-1,2-bis(1-indenyl) which is currently prepared from ZrCl.sub.4 and the dianion of the EBI ligand (Halterman, R. L. Chem. Rev. 1992, 92, 965). Brintzinger (Wild, F. R. W. P.; Wasiucionek, M.; Huttner, G., Brintzinger, H. H. J. Organomet. Chem. 1985, 288, 63) and Collins (Collins, S.; Kuntz, B. A.; Hong, Y. J. Org. Chem. 1989, 54, 4154; Collins, S.; Kuntz, B. A.; Taylor, N. J.; Ward, D. G. J. Organomet. Chem. 1988, 342, 21) used (EBI)Li.sub.2 and reported low, variable yields (20-50%) of rac-(EBI)ZrCl.sub.2. Buchwald employed (EBI)K.sub.2 and obtained (EBI)ZrCl.sub.2 in a rac/meso ratio of 2/1 in 70% yield. (Grossman, R. B.; Doyle, R. A.; Buchwald, S. L. Organometallics 1991, 10, 1501). In general, these salt elimination procedures produce the desired rac ansa-metallocenes in 10%-30% yield after tedious separation and purification steps, and the separation of the rac from the meso products is not always possible.
Ansa-metallocenes can also be prepared by amine elimination reactions of ansa-bis-cyclopentadienes and metal amide complexes as disclosed in U.S. Pat. No. 5,597,935. An example is the reaction of Zr(NMe.sub.2).sub.4 with 1,2-bis(3-indenyl)ethane ((EBI)H.sub.2), shown below (Eq. 2). This reaction provides an efficient, high-yield synthesis of pure rac-(EBI)Zr(NMe.sub.2).sub.2, which can easily be converted to rac-(EBI)ZrCl.sub.2 and related derivatives. ##STR2##
However, this amine elimination reaction produces the noxious gaseous amine NMe.sub.2 H as a byproduct which must be removed and disposed of. Additionally, the amine elimination approach is less useful for the synthesis of Ti or Hf ansa-metallocenes (order of reactivity: Zr>Hf>Ti) and does not work well with crowded metal amides, or crowded or weakly acidic cyclopentadienes. For example (EBI)H.sub.2 does not react with Ti(NMe.sub.2).sub.4 in toluene at 100.degree. C. (Diamond, G. M.; Jordan, R. F.; Petersen, J. L. Organometallics 1996, 15, 4030-4037). Also, the reaction of Hf(NMe.sub.2).sub.4 with (1-indenyl).sub.2 SiMe.sub.2 proceeds only under vigorous conditions (neat, 32 h, 120.degree. C.) to give rac-{(1-indenyl).sub.2 SiMe.sub.2 }Hf(NMe.sub.2).sub.2 in 20% isolated yield, and the rearrangement product Me.sub.2 Si(.eta..sup.5 -1-indenyl)(.eta..sup.3 -2-indenyl)HF(NMe.sub.2).sub.2 is observed as a side product (Christopher, J. N.; Jordan, R. F.; Petersen, J. L.; Young, V. G. Jr. Organometallics 1997, 16, 3044-3050).
Kunicki et al. reported that the simple unlinked metallocene (C.sub.5 H.sub.5).sub.2 TiCl.sub.2 can be prepared by the reaction of {(C.sub.5 H.sub.5).sub.2 Al(O.sup.i Pr)}.sub.2 with TiCl.sub.4 (Kunicki, A.; Sadowdki, R.; Zachara, J. J. Organometal. Chem. 1996, 508, 249). Ansa-metallocene complexes are not discussed in the Kunicki reference.
There is, therefore, a need for a process which would produce ansa-metallocene complexes in high yield without the formation of noxious gaseous byproducts. Additionally, there is a need for a process which would produce rac ansa-metallocenes in high yield without contamination by the meso isomer, since the rac isomer is most useful in stereoselective catalysis. The present invention has as its primary objectives the fulfillment of these needs.


A request is processed by a control device based on a detected proximity of a client device to the control device. The control device, which is intermediate to the client device and a beacon device, runs application software that receives the request generated using a client application running at the client device. The beacon device, upon receipt of an indication that the control device received the request, transmits a signal to detect a proximity of the client device to the control device. The application software receives data indicative of a response to the signal from the beacon device. The application software allows the request upon a determination that the data reflects the response is received. Alternatively, the application software allows the request upon a determination that the data indicates that the proximity of the client device to the control device satisfies a threshold.

Connected systems are used to facilitate transactions, such as by transmitting, receiving, and processing requests. A device of a connected system may receive a request from a remote device, such as by using wireless communications. The device processes the request and transmits a response to the remote device to reflect whether the request is allowed or denied. In one example, such request processing functionality may be used for processing transactions within a self-service market environment.

Proximity detection system for request processing


A chemical composition is provided for protecting, preserving, restoring and enhancing the appearance of rubber and polymer surfaces of de-icing boots on aircraft, particularly pneumatic de-icers. The chemical composition comprises the main elements of styrene acrylic emulsion polymer, polyethylene emulsion and polyolefin polymer emulsion, all mixed in distilled water. The preferred composition also includes 1,4 butanediol, polymethylsiloxane emulsion, potassium fluoroalkyl carboxylate, 12 benzisohiazolin 1-3, and ethylene glycol. A method of applying the composition to de-icer surfaces.

Most of the general aviation and commuter fleets of the world are fitted with ice protection systems. These systems usually include de-icer apparatus installed to cover various parts, including the wings, propellers and intake ports of the aircraft. The de-icer apparatus typically consist of one or more flexible members affixed to conform to the aerodynamic shape of the covered part of the aircraft. These de-icers are often pneumatic rubber boots having means by which the boots are sequenced through inflation and deflation cycles to crack and remove the ice that becomes attached thereto. Thus, the rubber composition of the boot is highly stressed and worn from continual pneumatic flexing as well as from being exposed to extreme temperatures and harsh environmental conditions.
More specifically, the function of these de-icing boots is to remove ice from the edge of the wing surface. This is accomplished by the de-icing boot cycling through an inflation and deflation process. As the rubber expands and then contracts, the ice breaks off and rids the plane of the excess weight of the ice. However, at low temperatures of at least about 5 degrees Fahrenheit, the ice removal efficiency of the de-icing boot is greatly reduced when compared to the efficiency of the ice removal at higher sub-freezing temperatures.
Consequently, there is a need for a special composition particularly adapted to be applied to flexible surfaces, such as rubber surfaces of de-icing boots, to act as a flexible protective agent and preservative and to restore and maintain flexibility of the rubber, thereby insuring long life. Such a composition must be able to withstand both the extreme environmental conditions to which aircraft are exposed and the high speeds of the aircraft.
In addition, de-icer apparatus is usually installed on the leading edges and front portions of various parts of aircraft so that they are highly visible. Thus, it is important that the boots maintain an attractive appearance despite the continual weathering and harsh conditions to which they are subjected. A composition for treating rubber surfaces is needed which will cosmetically enhance and improve the appearance of the surface as well as to act as a preservative and protectant.
Conventional preservative and protective compositions consisting of styrene acrylic and polyethylene emulsions are well known in the art. For example, U.S. Pat. No. 3,440,188 (Burdick et al) discloses a water base polish containing 70 to 80 percent by weight of an ethylene wax and an unspecified amount of a synthetic resinous polymer consisting of a homopolymer or copolymer styrene, and/or acrylic and methacrylic acid esters. The primary purpose of the composition disclosed in Burdick et al is to provide enhanced characteristics in all of the polish film properties, such as gloss, waterspot resistance, resistance to powdering or dusting, slip resistance, recoatability, removability, buffability, scuff resistance and the like. Another patent that discloses the use of styrenes in conjunction with suitable ethylene based waxes in U.S. Pat. No. 3,728,418 (Gleason). The composition in Gleason provides for a floor polish with a composition of a styrene copolymer emulsion and a styrene multi-polymer emulsion that inhibits the plasticizer in the vinyl floor covering from migrating from the vinyl floor covering into the floor polish.
Other prior art discloses de-icing or anti-icing compositions such as those disclosed in European applications Nos. 50,700 and 257,720 and U.S. Pat. Nos. 4,358,389 (Konig-Lumber et al), 4,636,324 (Murase et al), 4,744,913 (Salvador et al) and 4,954,279 (Ma et al). Most of these compositions contain a high percentage of glycol that reduces the freezing point of the water which melts the ice and thereby eliminating it from the surface to which it is applied. One patent (Murase et al) discloses a composition that contains a large percentage of organopolysiloxane which prevents the formation of ice on the surface to which it is applied. As is the case with the de-icing compositions containing glycol, the organopolysiloxane composition does not have any other protective characteristics and therefore, offers no advantage other than preventing the formation of ice.

Composition and method for preserving and restoring de-icer surfaces


A method of issuing a data retrieval command to a re-order unit in a bus bridge is described. The method requires maintaining an indication of the available (or unreserved) capacity in a data buffer into which a data package is received from a memory resource in response to a data retrieval command. Data packages are furthermore dispatched, relative to other data packages, in the order in which a corresponding data retrieval command is issued from a requesting device. The size of a data package requested by each data retrieval command is determined prior to issuance thereof to the re-order unit. The size of each data package is then compared to the then available capacity in the data buffer, and the relevant data retrieval command is only issued to the re-order unit if the available capacity in the data buffer is sufficient to accommodate the data package requested by the relevant data retrieval command.

Numerous methods have been proposed for achieving the efficient transfer of data retrieval commands and data packages issued in response to those commands, between a requesting device and a memory resource. One such method of increasing the efficiency of command and data package traffic involves establishing a communication protocol between the requesting device and the memory resource in which data packages are returned to the requesting device in the same order which respective data retrieval commands were issued from the requesting device. This allows for efficient streaming of data retrieval commands and data packages as the commands and data packages are identified by their respective locations in the command and data package streams. Accordingly, the requesting device is able to identify which data package was retrieved in response to which command from the order in which the data package is received at the requesting device. A higher degree of communication efficiency is achieved in that identifiers (e.g. memory location addresses) do not have to be associated with each data package so as to allow the requesting device to identify the data packages.
However, in order to increase the rate at which data is retrieved from a memory resource, for example an Extended Data Out (EDO) Random Access Memory (RAM), it may be desirable to re-order data retrieval commands included within a command stream. Specifically, when non-sequential commands address proximate locations in a memory resource, such as locations within a common page of a main memory, it is desirable to re-order such non-sequential commands so that they are received sequentially at the memory resource. By re-ordering the command stream, the overall access time to the memory resource may be reduced as, merely for example, the number of Row Address Strobe (RAS#) assertions and de-assertions and the associated pre-charging of circuitry within the memory source, are reduced.
When the re-ordering of commands occurs, it will be appreciated that the data packages retrieved in response to these commands may have to be re-ordered, prior to propagation to the requesting device, according to the original command order. This re-ordering may occur utilizing a data buffer. It is desirable to reduce the amount of die space dedicated to this buffer within an integrated circuit, and also to reduce the potential for thermal problems in the integrated circuit due to a large data buffer.

Method and apparatus for avoiding deadlock in the issuance of commands that are reordered and require data movement according to an original command order


An explosive structure of the fragmentation type includes an outer casing comprising an energy dense explosive material and having an inner surface defining a chamber and means for propagating shock waves across the inner surface from a selected one of at least first and second detonation points within the casing. The explosive structure further includes first means for directing shock waves, propagated from the first detonation point, against at least a selected portion of the inner surface in a first pattern for scoring and weakening the casing along first, segment-defining lines and second means for directing shock waves, propagated from the second detonation point, against the selected portion of the inner surface in a second pattern for scoring and weakening the casing along second, segment-defining lines, the segments of the second pattern being larger than the segments of the first pattern. The explosive structure further includes means for fragmenting the casing along the resulting, segment-defining lines scored in the casing.

1. Field of the Invention
This invention relates to an explosive, fragmentation structure and, more particularly, to an explosive, fragmentation structure having means for selectively controlling the radius of effects upon detonation of the fragmentation structure.
2. Description of Related Art
Fragmentation structures, such as fragmentation warheads, mines, etc., are employed by the military against a wide variety of targets where dispersion of fragments over a target area is required. A problem which arises in their use is that fragmentation warheads suitable for use against personnel are generally not suitable for use against "hard" targets such as armored vehicles and emplacements, where fragments of relatively greater size and mass are required. Military units have therefore been required to maintain supplies of several types of fragmentation warheads, each type adapted for use against a particular type of target. This results in an increased burden of logistics and supply and is, of course, highly undesirable. In the past, it has been attempted to minimize this problem by constructing warheads having two sections, one section being adapted to disperse fragments of one size and the other being adapted to disperse fragments of another size. In this manner, a single warhead may be utilized against a variety of targets. Such a construction, however, is inefficient in that, in each case, portions of the warhead not designed for the particular application are largely ineffective; furthermore, in order to produce a given amount of destructive force, a warhead of larger dimensions is necessary than would be the case for one designed for the specific application.
To address these problems, an explosive, fragmentation structure has been developed that includes means for selectively controlling fragment size and configuration. The structure includes an outer casing having an inner surface defining a chamber and further includes means for propagating shock waves across the inner surface from a selected one of two detonation points with the chamber. Means are provided for directing shock waves, propagated from the first detonation point, against the surface in a first pattern of segment-defining lines and for directing shock waves, propagated from the second detonation point, against the surface in a second pattern of lines which define segments larger than those of the first pattern. Thus, either larger segments or smaller segments can be selected depending upon the target.
Such explosive fragmentation structures, however, do not address "radius of effects" considerations. Generally, the term "radius of effects" means the distance from the detonated structure at which significant damage occurs. Conventional, explosive, fragmentation structures do not exhibit controlled radius of effects. Thus, such conventional, explosive, fragmentation structures may cause significant damage at radii greater than desired, causing undesirable collateral damage to personnel and/or equipment.
There are many designs of explosive, fragmentation structures well known in the art, however, considerable shortcomings remain.
While the invention is susceptible to various modifications and alternative forms, specific embodiments thereof have been shown by way of example in the drawings and are herein described in detail. It should be understood, however, that the description herein of specific embodiments is not intended to limit the invention to the particular forms disclosed, but on the contrary, the intention is to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the invention as defined by the appended claims.

Fragmentation warhead with selectable radius of effects


A method and apparatus for preventing and/or minimizing the formation of ice dams and icicles on a roof of a building having an unheated attic under said roof, which involves the steps of: (1) determining if there is an accumulation of snow on the roof, (2) determining ambient outdoor air temperature, (3) determining the temperature of air in the attic and (4) if there is an accumulation of snow on the roof and if the ambient outdoor air temperature is at or below freezing and if the attic air temperature is sufficient to cause melting of the snow on the roof, exhausting air from the attic.

It is well known in the United States, at least, that the formation of ice dams and icicles on the roofs of homes and other small buildings in winter weather is responsible for an excessive amount of damage to the homes, buildings and even the contents therein. The causes of ice damming and icicles are also well known, namely that when accumulated snow on a sloped roof top is caused to melt while ambient outdoor air temperatures are at or below the freezing temperature of water, or drop to such temperatures, the melt run-off flows downwardly on the sloped roof until it reaches an area of colder temperature, that is, sufficiently colder than the melt run-off is causing it to re-freeze, which normally occurs along the lower edge of the roof line, and/or within gutters and downspouts. Even though the ambient outdoor air temperature may not be warm enough to cause initial melting of such snow, such melting may nevertheless result due to other causes, such as from a rise in temperature within the unheated attic area of the home or building resulting from heat that escapes into the unheated attic area from the heated rooms therebelow. This rise in temperature can be more than insignificant as a snow covered roof acts as an excellent insulation to prevent heat loss through the snow covered roof.
While some older homes and buildings may have heated attics, present day home building practices usually provide an unheated attic, or at least an unheated air space between the top floor ceiling and the roof structure. Because such unheated attics and air spaces tend to become exceptionally cold in the wintertime, and exceptionally warm in the summertime, it is common practice to insulate the ceilings in the upper floors of the home or building from such unheated attics or air spaces, thereby insulating the living quarters from the outdoor air temperature, whether hot or cold. While the top floor ceiling is normally insulated, it is not normal practice to insulate the roof structure over the attic or air space. Thus, heat loss can normally be expected through the roof structure itself and while a snow cover will tend to insulate the attic air space, it does little to prevent heat loss into the roof structure itself. Accordingly, even though the attic air temperature may be only slightly above a freezing outdoor ambient air temperature, such a slight degree of warmth can be expected to warm the roof structure sufficiently to melt a considerable snow accumulation on the roof.
Normally, the melt run-off, as described above, will flow downwardly on a sloped roof under the snow cover until it reaches an area which is at or below the freezing temperature, such as roof surfaces not directly adjacent to the slightly warmed attic area, like the overhang area of the roof over the facia, and/or in gutters and downspouts, where the melt run-off then re-freezes to form ice. As the mass of such re-frozen run-off builds up, it can form what is commonly referred to as an "ice dam", which may form at the edge of the roof and tend to block the path of additional melt run-off. When ice dams form in gutters and downspouts, the gutters and downspouts can become blocked so that the run-off will overflow the edges of the gutters dripping downwardly to form icicles, which can accumulate and grow over time to very considerable sizes. It is of course well known that large icicles can present a significant danger to persons who must pass thereunder, not to mention damage to the gutters and downspouts themselves as a result of the weight of such icicles. In addition to the threat to personal safety and possible damage to gutters and downspouts, damage often results from the fact that the additional run-off, if so blocked at or near the edge of the roof by an ice dam, will tend to cause the blocked melt run-off to pool or back-up, seeping under the roof shingles and into the house or building so that the supporting wooden roof structure under the roof shingles not only becomes wet and water damaged, but the run-off can further seep or leak through the roof structure to cause water damage to the building walls and wall structures and even the building contents.
Unfortunately, traditional methods to alleviate the problems of ice dams and icicles are addressed primarily to treating the symptoms rather than the causes, in that home and building owners may often find themselves out-of-doors in cold winter weather knocking down icicles and/or chipping away ice dams. It is even more unfortunate that this effort itself often leads to damage to roof shingles, gutters and downspouts, with the very strong probability that the cycle will be repeated, with the ice dams and icicles reforming again.
One system that is available on the market to treat the causes of ice dams and icicles is the installation of one or more lengths of electrical heating cable which are usually installed in a zig-zag pattern adjacent to and along the lower edge of the roof. When properly installed, these heating cables are intended to heat at least certain roof areas to maintain one or more open molten water pathways along the edge of the roof thereby permitting molten run-off access to the gutters, to thereby prevent the formation of ice dams along the edge of the roof. To be completely effective, however, these electric heating cables should also be installed along the full width of the gutters and full length of the downspouts to a lever below grade, which unfortunately, is seldom the case.
In addition to the above discussed prior art concerning problems caused in winter weather, it is acknowledged that attic exhaust fans are well known which are used to overcome problems caused in hot summer weather. Such prior art attic fans normally include an electric motor driven fan adapted to exhaust exceptionally hot air from the attic of a home or building. Such exhaust fans are usually disposed at a high point of the attic ceiling, normally adjacent to a gable peak or apex between a pair of sloped roof surfaces. Such fans are generally mounted within a circular opening directly through the roof structure, such that the fan blade is aligned with and parallel to the roof, with the electric motor operatively connected to the fan blade, extending downwardly into the attic below the fan blades, and a "mushroom cap" type of cover secured to the roof directly over the fan blades to prevent the ingress of rain water and the like. A screen is also normally provided below the fan blades to prevent the ingress of insects and other unwanted solid debris. In the prior art, such exhaust fans have been solely utilized for the purposes of exhausting excessively hot attic air from the attic in summer weather to prevent heat conduction into ceiling surfaces therebelow, thereby assisting in efforts to keep the building cool with an air conditioning system. Indeed, despite the fact that the ceilings may be well insulated, such attic exhaust fans are well known to reduce electricity usage and bills by reducing air conditioner use.
Such attic fans of the prior art normally have a thermostatically controlled on-off switch which is adapted to turn the fan "on" when attic air reaches a temperature of 105.degree. F. to 115.degree. F. Even though the building ceiling is usually insulated against ambient air in the attic, it is known that, at least during exceptionally hot weather, enough heat is conducted through the insulated ceiling to warm such a ceiling and the air temperature in the upper rooms of the building, thereby reducing the effect of the air conditioning system in the building.

Method and apparatus for preventing the formation of ice dams and icicles on the roof of a house


A system for retaining a cross fire tube in a multi-combustor gas turbine engine is disclosed. The system comprises a flow sleeve having a generally annular body, and a flange at a forward end thereof and having one or more recessed portions. A cross fire tube extends through one or more openings in the flow sleeve and is secured in place by a retention clip. The retention clip includes a plurality of fingers which engage the cross fire tube and a mounting plate engaging the one or more recessed portions of the flow sleeve flange so as to create a clip engagement having a lower profile than prior art configurations.

A gas turbine engine typically comprises a multi-stage compressor coupled to a multi-stage turbine via an axial shaft. Air enters the gas turbine engine and passes through the compressor where its temperature and pressure increase as it passes through subsequent stages of the compressor. The compressed air is then directed to one or more combustors where it mixes with a fuel source to create a combustible mixture. This mixture is ignited in the one or more combustors to create a flow of hot combustion gases. These gases are directed into the turbine causing the turbine to rotate, thereby driving the compressor. The output of the gas turbine engine can be mechanical thrust via exhaust from the turbine or shaft power from the rotation of an axial shaft, where the axial shaft can drive a generator to produce electricity.
In a typical industrial gas turbine engine, the combustor section comprises a plurality of can-annular combustors. In this configuration, a plurality of individual combustors is arranged about the axis of the gas turbine engine, where each combustor receives a portion of the compressed air from the compressor. However, in order to eliminate the need for ignition sources in each combustor for use at start-up as well as any time a combustor flashes back or when a flame is unintentionally extinguished, the plurality of individual combustors is connected by a plurality of cross fire tubes. In operation, one combustor can be ignited, and the flame will pass through the cross fire tubes to an adjacent combustor, thereby igniting a combustible mixture in an adjacent combustor.
A cross fire tube arrangement in accordance with the prior art is disclosed in FIGS. 1-4. Referring initially to FIG. 1, a flow sleeve 100 is shown and includes a plurality of openings 102 in the wall of the flow sleeve. The flow sleeve 100 also includes a plurality of lugs 104, which are used for positioning a combustion liner within the flow sleeve 100. Also located within the flow sleeve 100 are a plurality of brackets 106, which are more clearly depicted in FIG. 2. The cross fire tubes 108 are placed through the openings 102 and brackets 106, as shown in FIG. 3.
Referring now to FIG. 4, the cross fire tubes 108 are secured in the flow sleeve/liner by a clip 110. The clip 110 includes a hook portion 112 which can be used to help install and remove the clip 110 from the flow sleeve 100. As a result of the configuration of the bracket 106 and clip 110, each of these features extend inward and into a flow path between the flow sleeve 100 and combustion liner (not shown), thus interfering and restricting the flow of air passing between the flow sleeve 100 and a combustion liner. In a common configuration, the bracket 106 and clip 110 extend over half an inch into the flow path of the passing airflow thus adversely impacting air flow to a combustor and combustion dynamics and emissions.


A semiconductor device and a fabrication method thereof are provided. The semiconductor device includes a semiconductor substrate which comprise a first type well and a second type well, and a plurality of junction regions therebetween, wherein each of the junction regions adjoins the first and the second type wells. A gate electrode disposed on the semiconductor substrate and overlies at least two of the junction regions. A source and a drain are in the semiconductor substrate oppositely adjacent to the gate electrode.

1. Field of the Invention
The present invention relates to a method for fabricating a semiconductor device, and in particular relates to a method for fabricating a semiconductor device for increasing operation voltage.
1. Description of the Related Art
High voltage MOS transistors are widely used in many electronic devices, such as central processing unit voltage supply devices, power supply manager system devices and AC/DC inverters and the like. Because high voltage MOS transistors are usually operated under high operation voltage, a high electric field may be formed, resulting in a large number of hot electrons near the junction region of the channel and the drain. The hot electrons will excite the electrons near the drain to the conduction band to form an electron-hole pair, thereby affecting covalent electrons near the drain. Most of the electrons ionized by hot electrons may move to the drain to increase drain current (Isub), and a small portion of the ionized electrons may be injected into and trapped by the gate oxide, resulting in changing the threshold voltage of a gate electrode. Additionally, the holes resulting from hot electrons may flow to the substrate to produce a drain current (Isub). Thus, when the operation voltage increase, the number of electron-hole pair increases and results in "carrier multiplication".
FIG. 1 shows a cross-section view of a traditional high voltage MOS transistor with a lateral diffused drain. As FIG. 1 shows, a high voltage MOS transistor 130 is formed on a semiconductor wafer 110. The semiconductor wafer 110 has a P-type silicon substrate 111 and a P-type epitaxial layer 112 formed on the P-type silicon substrate 111. The high voltage MOS transistor 130 has a P-type well 121, N-type source region 122 formed in the P-type well 121, an N-type drain region 124 formed in the P-type epitaxial layer 112, and a gate electrode 114.
When the drain current mentioned above flows through the P-type silicon substrate 111, the resistance (Rsub) of the P-type silicon substrate 111 may produce an induced voltage (Vb). If the induced voltage is large enough, forward bias may occur between the P-type silicon substrate 111 and the source region 122 to form a parasitic bipolar transistor 140. When the parasitic bipolar transistor 140 is turned on, the current from the drain region 124 flowing to source region 122 is rapidly increased, resulting in electrical breakdown to cause the high voltage MOS transistor 130 to malfunction.
In some high voltage MOS devices, in order to provide a high voltage, "double diffused drain" structures are used in the source and drain. FIG. 2 shows a high voltage MOS transistor with a double diffused drain structure disclosed by U.S. Pat. No. 5,770,880. A substrate 210 has an N-type body 212. A gate 220 on a gate oxide 222 is formed between a source 230 and a drain 240. The source and drain are substantially the same and interchangable, therefore only the drain is described in the flowing. Every drain has a double diffuse region comprising a first heavily doped contact region 214 and a lightly doped region 216. The diffusion regions are formed by implanting P-type ions such as boron into the exposed surface of the substrate after forming an open 219 on the oxide layer and performing an annealing process to make P-type ions diffuse into the substrate 210 to form the doped regions 214 and 216. The contact region 214 is usually limited on the surface of the N-type body 212 and do not extend into the N-type body 212. The second lightly doped region 216 extends into the N-type body 212 and a portion of the second lightly doped region 216 is under the gate electrode 220. A junction region is formed between the doped region 216 and N-type body 212 and the junction region determines the breakdown voltage value of the device. The diffusion doped region 216, having a low doping concentration gradient, may decrease the reverse bias electric field near the body-drain junction region. Specifically, this allows the device to operate under a high voltage before reaching the breakdown voltage. However, fabricating the device mentioned above requires a complicated process and additional masks may be needed, thus increasing costs. Therefore, a new semiconductor device and a fabrication method thereof are needed to improve the breakdown voltage of the device without incurring extra costs.

Semiconductor device and fabrication method thereof

Vanguard International Semiconductor Corporation


An apparatus (10) is disclosed for measuring the mass flow of pneumatically conveyed particles along a transport tube 14. The apparatus includes a fluidized bed of the particles 16 and an application device or collection box 18. The improvement comprises means for unfluidizing the fluidized particles in communication with the fluidized bed. Additionally, one or more augers 22 are provided for delivering particles at a predetermined air pressure in predetermined amounts in communication with the means for unfluidizing and one or more pumps 24 are provided downstream from the one or more augers 22. A sensor 26 is downstream from the one or more pumps. The particles then are conveyed from the sensor to the collection box. A method is also provided to measure the mass flow of pneumatically conveyed particles along a transport tube with an apparatus which includes a fluidized bed of the particles and a collection box. The improvement comprises unfluidizing the fluidized particles in the fluidized bed, delivering the unfluidized particles via a hopper through an auger, and pneumatically conveying the unfluidized particles through a pump situated downstream from the auger. Finally, the mass flow is sensed by a sensor downstream from the pump.

Precise measurement of the flow rate of powder conveyed by a fluid is relevant to various technologies besides powder painting--food processing, toner manufacturing, and coal processing industries to name a few.
It is known to provide powder flow rate measuring devices between a fluidized powder storage tank and a powder conveyor device including a compressed air pump which imparts to the air-powder mixture sufficient energy to enable it to be conveyed in a transport to a device at which it is applied.
The prior art includes two main types of flow meters: (1) the so-called true mass flow meter, which responds directly to mass flow rate, and (2) the inferential mass flow meter, which commonly measures volume flow rate and fluid density separately. PERRY'S HANDBOOK OF CHEMICAL ENGINEERING. When measuring mass flow of pneumatically conveyed powder paint particles, one potential "true mass flow meter" relies on the Coriolis effect. However, Coriolis meters are inappropriate for powder painting production applications due to impact fusion. When particles are pneumatically conveyed through curved tubing, inertia of the particles causes some of them to collide with the walls of the tube. The energy of the impact results in fusion of some of the particles to the tube walls. Experience with the problem indicates that 1/2-inch tubes can become entirely blocked in less than three months.
Inferential mass flow meters are limited by problems associated with particle velocity and the volume ratio of powder to air (or concentration if powder density is constant).
Capacitance has also been used as a method for particle concentration measurement. The dielectric constant of a dilute particle-air mixture is is a function of the concentration of that mixture. If tubing is configured to be a capacitor, changes in particle-air concentration will change the dielectric constant, which in turn will change the capacitance of the capacitor. U.S. Pat. No. 3,636,763 is illustrative of such approaches. Other approaches in using capacitance technology to measure particle velocity are disclosed in U.S. Pat. Nos. 3,595,078 and 3,635,082.
It is now conventional to use the Doppler effect to measure velocity and concentration of fluids using laser and ultrasonic energy sources for the Doppler devices. Laser-based systems, however, are intrusive--they must be mounted so that the laser beam "sees" the flow. This limits their effectiveness in powder applications because powder buildup on the sensor window would blind a laser-based system and render it useless. Also, ultrasonic approaches tend to suffer from problems stemming from environmental noise. Additionally, the sensors tend to be very dependent upon solids content. Ultrasonic sensors are disclosed in U.S. Pat. No. 4,882,934.

Apparatus and method for measuring the mass flow of pneumatically conveyed particles


Several 2D and 3D HiNAND flash memory arrays with 1-level or 2-level broken BL-hierarchical structures are provided for Multiple Whole-WL and All-BL simultaneous operations in Dispersed Blocks. The global bit line (GBL) is divided to multiple 1(top)-level broken metal2 GBLs plus optional lower-level broken metal1 local bit lines (LBLs). A preferred Vinhibit supply higher than Vdd can be selectively supplied via horizontal metal0 power line LBLps to charge selected broken GBLs/LBLs which can also be selectively discharged via a String source line. Charge-sharing technique for precharging and discharging of broken GBL/LBL capacitors for NAND cell data sensing is used in Read and Verify operations with reduced power consumption and latency. Recall technique to restore the desired Program Data stored in the broken GBL/LBL capacitors is used for Multiple-WL and All-BL Program and Program-Verify operation with reduced program current for highest program yield superior P/E cycles.

The present invention generally relates to advanced NAND memory technology. More specifically, the invention provides a repeatedly electrically erasable and programmable 2D or 3D NAND memory array comprising a unified multi-level hierarchical broken Bit Line (BL) structure that enables superfast and low-power Multiple Word Line (WL) and All-BL Simultaneous Erase, Erase-Verify, Program, Program-Verify and Read operations.
Conventionally, a 2D NAND flash includes several 2-dimensional (2D) planes on a common Triple P-well within a deep N-well on top of a common silicon P-substrate. When 2D NAND flash technology is scaled down below 2×nm for increasing NAND memory size, it hits the wall to meet the Moore's scaling law, good data reliability and short latency. The reliability issues include short data retention life cycle, high power-consumption and low Program, Erase and Read cycles. The slow latency issues include slow page-Read, page-Program, page-Program-verification, block-Erase and page-Erase-verification, etc.
The WL page size can be defined either in a large physical page size such as whole WL or a smaller logic size such as ½ or ¼ of a whole physical WL. The NAND's data storage types can be SLC, MLC, TLC, XLC or even an analog one that stores more than 16 states per one physical NAND cell, regardless of 2D or 3D NAND memory.
Recently, many new 3D NAND flash memory cells and array architectures have been proposed by using 3D transistors and Strings with a cylindrical column type structures such as a multiple-layer stacked vertical-channel (VCh1) 3D NAND technology from Toshiba, SanDisk and Samsung, or a vertical-gate (Vgat) NAND String technology from Samsung, and Macronix (Taiwan) and other 3D NAND flash technologies from Hynix, and Micron.
Although a 3D NAND flash memory has many advantages to use the less advanced technology nodes to increase NAND density over 1 Tb with a smaller silicon area than 2D NAND, it encounters new process disadvantages such as high aspect ratio, stair-case etching etc, more WL disturbance and new challenges to use the new scheme of gate-induced-drain-leakage (GIDL) current to erase the 3D NAND flash cells, etc.
Irrespective of 2D or 3D NAND flash pros and cons under development, there are many common long-held old and new problems not being completely solved and instead being mitigated when further scaling below 2×nm. For example, the conventional 20-year good SBPI (Self-Boosting-Program-Inhibit) scheme has been found un-reliable in Program and Program-Inhibit operations due to larger proximity coupling effects such as the charging and discharging of adjacent BL-BL coupling noises.
In other words, the conventional SBPI operations are strongly affected by the stored Vts of two surrounding NAND cells dispersed in the adjacent left and right BLs. These coupling noise effects greatly degrade the NAND data reliability and integrity, thus more errors and less P/E/R cycles are produced. As a result, more sophisticated ECC algorithms are required to use those NAND memories made of more advanced nodes below 3×nm.
As NAND density will be quickly exceeding 1 Tb with the circuit layout scaled down to 10 nm or below, more power consumptions and latencies in Read, Program, and Erase operations are commonly found in product specs. It is desirable to improve NAND memory technology to solve the above problems. The present invention provides a superfast, superior, and unified broken-BL hierarchical NAND array structure plus DRAM-like BL Charge-sharing and Sensing plus a novel Recall circuit aimed for implementing Multiple-WL and All-BL simultaneous Erase, Erase-Verify, Program, Program-Verify, and Read operations on today's 2D and 3D NAND flash designs without cell and process changes, as described throughout the specification and all figures.

NAND array hiarchical BL structures for multiple-WL and all-BL simultaneous erase, erase-verify, program, program-verify, and read operations


A multi-layer printed circuit board structure, a connector module and a memory storage device are provided. The multi-layer printed circuit board structure includes a first layout layer and a second layout layer. The first layout layer includes a shielding element and at least one pad. The shielding element provides the grounding voltage. The second layout layer is disposed corresponding to the first layout layer and includes at least one wire, and one end of each wire is coupled to one of the pads. A predefined proportion of the wire is covered by a projection plane of the shielding element projected on the second layout layer.

1. Technology Field
The present invention is directed to a layout of a printed circuit board (PCB) and more particularly, to a multi-layer printed circuit board (MLPCB) structure, a connector module and a memory storage device.
2. Description of Related Art
With advancement of technologies for manufacturing printed circuit boards (PCB) and electronic components, the printed circuit boards and the electronic components are tended to be designed with small sizes to meet the demands for miniaturization of electronic products. However, reduction of a size of a printed circuit board results in less area available for layout on the printed circuit board. A layout design of a multilayer printed circuit board (MLPCB) is therefore proposed to increase the layout area based on a premise that the size of the printed circuit board is not increased. Generally, in the layout design of the multilayer printed circuit board, signal layers are disposed on outer layers of the multilayer printed circuit boards, while a power layer and a ground layer are disposed on an inner layer of the multilayer printed circuit board. However, in such layout manner, signals transmitted on the signal layers may cause electromagnetic interference (EMI) to electronic apparatuses nearby.
Nothing herein should be construed as an admission of knowledge in the prior art of any portion of the present invention. Furthermore, citation or identification of any document in this application is not an admission that such document is available as prior art to the present invention, or that any reference forms a part of the common general knowledge in the art.

Multi-layer printed circuit board structure, connector module and memory storage device


A method for purifying a cucurbituril from a mixture. The method includes the step of forming a complex between the cucurbituril and a cucurbituril guest. The complex has altered physical and/or chemical properties to the cucurbituril which allow the complex to be separated from at least one other component of the mixture. The mixture includes the cucurbituril, the other component and a solvent.

The cucurbit[n]uril (CB[n]) family has been extensively studied in recent years on account of their scope within the fields of molecular recognition and aqueous self-assembly.[1] CB[7], a member of the CB[n] family, has a substantially higher water solubility than CB[6] and CB[8] and a larger binding cavity than its water soluble brother, CB[5].[2]
Recent reports have shown that CB[7] is an excellent host for binding and stabilising a wide range of small molecules, such as fluorescent dyes,[3] controlling aggregate formation of guest molecules,[4] and for use in light-harvesting systems.[5] However, a major drawback which has limited the study and application of CB[7] is its difficult isolation and purification from the synthesised mixture of CB[n] homologues.
Traditional isolation methods of CB[7] are based on the different solubilities of CB[n] in various solvents, such as acetone/water and methanol/water mixtures, limiting the overall yield of CB[7] to just under 3%.[6, 7] Nau et al. [8] has reported a more direct approach to preparing CB[7] by controlling the direct reaction of formaldehyde, glycoluril and sulfuric acid, followed by a similar isolation methodology based on solubility of CB[7] in an acetone/water mixture. This method gives a substantially better yield with higher purity, however, the separation and purification is still based primarily on solubility differences in a variety of mixed solvents. For the standard separation routes, it is difficult to obtain CB[7] in high purity as both CB[5] and CB[7] have low solubility in the mixed solvent systems (either acetone/H2O or MeOH/H2O), requiring multiple solvent-based separation cycles.
Another isolation method which has been reported by Isaacs et al. uses column chromatography with a harsh acidic eluent HCO2H (88%):HCl (0.2 M) (1:1 v/v).[9] This can be a highly toxic process which results in acidic products and may limit the viability of scale-up.
The use of alkyl imidazolium salts to form complexes with cucurbituril compounds has been described [18], although this disclosure was made after the priority date of the present application.
Herein is reported a new cucurbituril isolation method which is convenient for obtaining pure cucurbituril material, is inherently more environmentally friendly and suitable for large scale purification by exploiting the reversible association and dissociation of a host-guest complex in a controlled manner.

Methods for the purification of cucurbituril


Methods for fabricating a shallow trench isolation (STI) of a semiconductor device are disclosed. A disclosed method includes: forming a trench on a semiconductor substrate, forming an oxide layer on the semiconductor substrate and the trench, forming a photoresist pattern on the oxide layer exposing the oxide layer on a bottom surface of the trench, forming STI films on sidewalls of the trench by etching the exposed oxide layer using the photoresist pattern as an etch protection layer, removing the photoresist pattern, developing an epitaxial layer between the STI, and planarizing the epitaxial layer and the oxide layer.

Typically, a trench of a semiconductor device is formed by sequentially depositing a pad oxide layer (SiO2) and a nitride layer (SiNx) on a silicon substrate. The pad oxide layer and the nitride layer are patterned to expose the silicon substrate. Then, the exposed silicon substrate is etched to a predetermined depth using the patterned nitride layer as an etch protection layer to thereby form a trench pattern in the silicon substrate.
Subsequently, a thermal oxide layer is formed inside the trench pattern via a thermal oxidation process. Another oxide layer is deposited over the thermal oxide layer within the shallow trench. The oxide layer is thermally treated to form a shallow trench isolation (STI) structure within the trench pattern. The STI formed on the semiconductor substrate is planarized through a chemical mechanical polishing process (CMP) to complete the STI film.
However, the conventional STI fabrication method has drawbacks. For example, it is difficult to reduce the linewidth of the STI film. Further, scratches and particles may occur during the CMP process.
To clarify multiple layers and regions, the thickness of the layers are enlarged in the drawings. Wherever possible, the same reference numbers will be used throughout the drawing(s) and accompanying written description to refer to the same or like parts. As used in this patent, stating that any part (e.g., a layer, film, area, or plate) is in any way positioned on (e.g., positioned on, located on, disposed on, or formed on, etc.) another part, means that the referenced part is either in contact with the other part, or that the referenced part is above the other part with one or more intermediate part(s) located therebetween. Stating that any part is in contact with another part means that there is no intermediate part between the two parts.

Methods for fabricating an STI film of a semiconductor device


A syringe barrel includes: a barrel body including a nozzle portion at a distal end thereof; and a cap removably mounted to the nozzle portion and configured to seal a distal end opening of the nozzle portion. The cap includes: an inner cap formed of an elastic material and configured to come in liquid tight contact with the nozzle portion in a mounted state in which the cap is mounted to the nozzle portion, and a cylindrical outer cap formed of a material having a higher hardness than the inner cap and fixed around the inner cap. The inner cap includes: a base portion, and a cylindrical wall extending from the base portion in a proximal direction and surrounding the nozzle portion.

The present disclosure relates to a syringe barrel, a syringe barrel manufacturing method, and a pre-filled syringe.
In a conventional pre-filled syringe that is pre-filled with a liquid, a cap to close a nozzle portion in a liquid tight manner is mounted to a distal end of a barrel in order to inhibit leakage of a liquid inside the syringe from a syringe distal end opening prior to use of the syringe, particularly during transportation (refer to, for example, JP 2736245 B2).
The cap disclosed in JP 2736245 B2 includes an inner cap formed of an elastic material and a hard outer cap fixed around the inner cap, with an outer screw provided on the outer cap being configured to be engaged with an inner screw provided at a Luer collar fixed at a distal end portion of a syringe barrel, so as to cause the inner cap to seal the distal end portion of the syringe barrel in a liquid tight manner.

Syringe barrel, method for manufacturing same, and pre-filled syringe


A shoe, especially an athletic, leisure or rehabilitation shoe, with an upper part consisting, at least partially, of a flexible material which covers the ankle of the foot (3/4 mid-height) or rises above the ankle (high top) and which is provided with an instep cover coveting the instep of the foot (which is movable like a tongue or forms the tongue or a part of it) on which a central rotary closure is provided, with which at least the instep length of at least one tightening element can be shortened for closing the shoe and can be extended for opening it, and the tightening element is alternately guided respectively from a guide element on the upper side part to a guide element of the instep cover. To achieve a quick closure of such a shoe with a central rotary closure, while maintaining its usual size for low top shoes, also in shoes to be opened wide and in those with a high top upper, for example, in basketball or volleyball shoes, in addition to a central rotary closure, a sliding closure is provided that can be engaged or disengaged at least in the closed position, and which is also coupled with the tightening element and which makes possible a tightening in one sliding direction and a relaxing of the tightening element or elements in the other sliding direction.

This invention relates to a shoe, especially an athletic, leisure or rehabilitation shoe, with an upper part consisting, at least partially, of a flexible material which covers the ankle of the foot (3/4 mid-height) or rises above the ankle (high top). More specifically, the invention relates to a shoe of this type which is provided with an instep cover covering the instep of the foot (which is movable like a tongue or forms the tongue or a part of it) on which a central rotary closure is provided, with which at least the instep length of a tightening element can be shortened for closing the shoe and can be extended for opening it, and the tightening element is alternately guided respectively from a guide element on the upper side part to a guide element of the instep cover.
Such a sport shoe is known, for example, from commonly owned, co-pending U.S. patent application No. 08/010,385, and low top versions of such shoes are disclosed in U.S. Pat. Nos. 5,177,882 and 5,117,567. In using the known central closure of the noted patents for shoes which have a very large open throat area or in shoes with a high top upper, which by nature have a greater throat area, the central rotary closure has to be able to accommodate a large lengthwise section of the tightening element in the closed position. Therefore, it has to have a correspondingly large winding space for the tightening element. Otherwise, to obtain an effective closure, as disclosed in the noted co-pending patent application, a more complex double-reel central closure must be used with multiple tightening elements.
Sliding closures for shoes are also known; for example, a sliding closure is known from U.S. Pat. No. 2,994,935 which extends over the entire length of the tongue. It consists of a relatively rigid material. A good matching of the shoe in this sliding area to the shape of the foot is, therefore, not possible. A shortening of the sliding path of the sliding closure is not possible because of the necessary opening angle of the upper side parts and the, thus, necessary large instep length of the tightening element. Therefore, such sliding closures could not catch on in the market.
Similarly, zipper-type closures are known, for example, from U.S. Pat. No. 2,345,057 and French Utility Model Publication 2501977. These closures, which are attached to the shoe upper by conventional shoe laces, also, extend over the entire length of the tongue.

Shoe, especially an athletic, leisure or rehabilitation shoe having a central closure


Inventive embodiments are directed to components, subassemblies, systems, and/or methods for electric traction drives employing a continuously variable transmission (CVT) having a variator provided with a plurality of tilting traction planets and opposing traction rings. In one embodiment, an electric traction drive is provided with an electromotive device configured to transfer power to or from a traction sun of a CVT. In other embodiments, an electric traction drive is provided with an electromotive device that couples to certain components of a CVT such as a traction ring, a carrier assembly, and a main axle. Various inventive shifting assemblies having shift cams and shift cam cages can be used to facilitate adjusting the transmission speed ratio of a CVT. Various related devices include embodiments of, for example, a power input apparatus, a speed ratio shifter, a shift cam actuator, a shift nut, and a carrier assembly configured to support the tilting traction planets.

Field of the Invention
The field of the inventive embodiments disclosed here relates generally to systems and methods for electromechanical or electromotive drives, and more particularly the inventive embodiments relate to drives that use methods and assemblies that incorporate electrical device components and continuously or infinitely variable transmission components.
Description of the Related Art
To provide a continuously variable transmission (CVT) or an infinitely variable transmission (IVT), various traction roller transmissions in which power flows through traction rollers between torque input and output rings have been developed. In such transmissions, the traction rollers mount on structures that when pivoted cause the traction rollers to engage the torque rings in circles of varying diameters depending on a desired transmission ratio.
A known CVT includes a shaft about which input and output rings rotate. The input and output rings mount on the shaft and contact a plurality of traction rollers disposed equidistantly and angularly about the shaft. The traction rollers are in frictional or, tractional contact with both rings and transmit power from the input ring to the output ring. An idler located concentrically over the shaft and between the balls applies a force to keep the traction rollers in contact with the input ring and output ring.
An electric motor producing variable speed and constant power is highly desired in some vehicle and industrial uses. In such constant power applications, torque and speed vary inversely. For example, torque increases as speed decreases or torque decreases as speed increases. Some electric motors can provide constant power above their rated power; for example, a 1750 rpm AC motor can provide constant power when speed increases above 1750 rpm because torque can be designed to decrease proportionally with the speed increase. However, a motor by itself cannot produce constant power when operating at a speed below its rated power. Frequently torque remains constant or even decreases as the motor speed decreases. Controllers can be used to increase current, and torque, into the electric motor at low speeds, but an increase in the wire diameter of the windings is required to accommodate the additional current to avoid overheating. This is undesirable because the motor becomes larger and more expensive than necessary for typical operating conditions. The electronic controller also increases expense and complexity. Another method to achieve sufficient low speed torque is to use a bigger motor. However, this increases cost, size, weight, and makes the motor more difficult to package with the machine it powers. Thus, there exists a need for an improved method to provide variable speed and constant power with an electric motor. The continuously variable transmission can be integrated with an electric motor for some applications.

Fallbrook Intellectual Property Company LLC


A mobile audio stream broadcasting method has steps as follows: establishing a fist Bluetooth (BT) connection between a mobile device and at least one of a plurality of BT speakers; detecting connection signal strength and designating the BT speaker with maximum of connection signal strength as a first BT target speaker; establishing a second BT connection; transmitting an audio stream data to the first BT target speaker for broadcasting music via the second BT connection; detecting connection signal strength of the first BT target speaker continuously and automatically via the first BT connection; determining whether connection signal strength of the first BT target speaker is lower than a preset threshold value; if connection signal strength of the first BT target speaker is lower than the preset threshold value, then disconnecting the first and the second BT connections between the mobile device and the first BT target speaker.

1. Field of the Invention
The instant disclosure relates to a mobile audio stream broadcasting method and a mobile audio stream broadcasting system; in particular, to a mobile audio stream broadcasting method and a mobile audio stream broadcasting system which can automatically switch or disconnect the connection according to the location of a mobile device.
2. Description of Related Art
Bluetooth is a wireless communication technology able to be applied to computer, mobile phone, and other electric devices. The operation of Bluetooth is to transport with the bandwidth of 2.45 GHz. In addition to digital data, the audio information can be transmitted also. Each device using Bluetooth communication technology has a 48-bit address set according to the IEEE 802 standard, which allows an one-to-one connection or an one-to-many connection and allows a maximum transmitting distance of 10 meters. The Bluetooth technology not only allows a big amount of transmission and also gives the transmitting speed reaching to 1 MB per second. Also, the Bluetooth technology allows setting codes for protection, and allows the frequency to change for 1,600 times per minute. Thus, it is hard to have an interception and wouldn't be interfered by the electromagnetic wave. With the well-developed technology, currently, the smart phone can be matched with wireless peripheral equipments having Bluetooth chips via the Bluetooth wireless transmitting technology, and then the user can use the matched wireless peripheral equipments together with the smart phone. In particular, the Bluetooth speaker is one of the focused and popular products, which makes the user to broadcast the audio data stored in the smart phone anytime and anywhere. The generally Bluetooth speaker is an one-to-one device, which means that one smart phone is corresponded to one speaker. Even for the speaker having multi-drop connection, it is generally for several smart phones to be corresponded to one speaker.

Mobile audio stream broadcasting method and system


This invention provides a novel pyrin-only protein (POP2), polypeptides, and nucleic acids encoding them and methods for making and using them. POP2 is a 294 nt single exon gene located on human chromosome 3 encoding a 97 amino acid protein with sequence and predicted structural similarity to other pyrin domains. Highly similar to pyrin domains in CATERPILLER (CLR, NLR, NALP) family proteins, POP2 is less like the prototypic Pyrin and ASC pyrin domains. POP2 is expressed principally in peripheral blood leukocytes and displays both cytoplasmic and nuclear expression patterns in transfected cells. TNFα-stimulated and p65 (RelA) induced NF-κB-dependent gene transcription is inhibited by POP2 in vitro by a mechanism involving changes in NF-κB nuclear import or distribution. While colocalizing with ASC in perinuclear specks, POP2 also inhibits the formation of specks by the CLR protein CIAS1/NALP3. POP2 is a negative regulator of NF-κB activity that may influence the assembly of pyrin-domain dependent complexes.

Activation of NF-κB regulates numerous cellular processes including cytokine and adhesion molecule expression, cell-cycle regulation and cell growth. Constitutive or excessive NF-κB activity is thus observed in inflammatory diseases, autoimmunity and cancer. Notably, active NF-κB also protects against apoptosis which may contribute to the accumulation of inflammatory, self-reactive or cancerous cells.
Extensive research has been conducted throughout the last decade towards understanding the molecular mechanism, signaling pathways and physiological role of proteins containing the death domain fold (DDF) associated with NF-κB signaling and apoptosis induction. Four related protein-protein interaction domains comprise the DDF superfamily: the death domain (DD); the death effector domain (DED); the caspase recruitment domain (CARD) and the pyrin domain (PYD). These domains share a similar tertiary structure, a 5 to 6 α-helical bundle that likely function as homotypic interaction modules. Acting as signaling adapters and recruiters of proteins into sub-cellular complexes domains of this type participate in the promotion and regulation of apoptosis, innate immunity and cancer development.
Pyrin motifs are generally found at the N-terminus of multidomain proteins. Pyrin (marenostrin), the founding member of the family, is associated with Familial Mediterranean Fever (FMF), an autosomal recessive disease characterized by sporadic attacks of fever and intense abdominal, joint and chest pain. Following its PYD, Pyrin contains a B-box zinc finger and a SPRY domain believed to function as adaptor and ligand binding units, respectively. Interferon inducible (IFI) genes, which code for the HIN-200 family of hematopoetic nuclear proteins and contain one or two copies of a 200-amino-acid domain believed to mediate protein/protein interactions, are preceded by a PYD. Evidence supporting the role of HIN-200 proteins in controlling cell proliferation and differentiation has been previously documented. The pyrin domain of Apoptosis speck protein containing a CARD, ASC (TMS1/Pycard) is followed by a CARD domain. ASC associates with PYD- or CARD-containing proteins through homotypic interactions via both domains. In proapoptotic cells, ASC assembles in large multimeric perinuclear complexes or 'specks' by interacting with PYD-containing proteins. The physiological significance of these interactions and that of the speck structure itself remains unclear. ASC also participates in the formation of the inflammasome complex that processes pro IL-1β into the mature form and is up-regulated in neutrophils during inflammation. Two thirds of the 21 members of the recently discovered CATERPILLER (CLR) gene family thought to play an important role in vertebrate immunity functioning as intracellular pathogen-recognizing units, encode a PYD followed by a nucleotide binding domain (NBD) and leucine-rich repeats domain (LRR). CLR proteins have been postulated as modulators of ongoing inflammatory responses and as inducers of apoptosis. Some PYD-containing proteins of the CLR family have been reported to induce NF-κB activation in conjunction with ASC, including PYPAF5, Monarch, and CIAS1. Not surprisingly, mutations in CIAS1/NALP3 associated with the inflammatory syndromes familial cold urticaria, Muckle-Wells, and chronic infantile neurologic cutaneous articular syndrome, showed increased capacity for ASC-dependent NF-κB activation. Other CLRs, such as PAN2/PYPAF4 mediate NF-κB suppression. Although the NBD/LRR of CIAS1 inhibits NF-κB nuclear import, the pyrin domain of PAN2/PYPAF4 inhibits NF-κB, a function that may be mediated through the IKK complex.
The NF-κB family of transcription factors is comprised of five members in mammals: p65 (Rel A), Rel B, c-Rel, p50/p105 and p52/p100, existing as homo- or heterodimers bound to the IκB inhibitory complex in the cytosol. Upon induction by proinflammatory stimuli such as TNF-α or LPS, IκBα is phosphorylated by the IκB kinase (IKK) complex, ubiquitinated and degraded by the 26S proteasome. This process unmasks NF-κB's nuclear localization sequence, leading to its translocation into the nucleus. Binding of NF-κB to its cognate DNA response elements induces the transcription of a host of cytokines and growth factors (e.g. IL-2, II-8, IFN-β, M-CSF, G-CSF, VEGF), as well as various transcription factors and signaling regulators (e.g. IκBα, IRF-1, IRF-2). The pivotal role of NF-κB in biological processes modulating the immune response suggests that localization and subsequent activation must be rigorously controlled. Dysregulation of these events leads to aberrant gene expression associated with numerous human diseases including cancer, neurodegenerative disorders, arthritis and chronic inflammation.
Solitary pyrin domains may disrupt pyrin domain interactions, potentially blocking the formation of speck and/or inflammasome complexes and their downstream effects. Genes comprised exclusively of a PYD have recently been identified in the human genome and in the genomes of pox viruses. Pyrin-only protein 1 (POP1), is encoded by a gene in the close proximity to ASC, suggesting that Pop1 might have arisen from an ancient gene duplication event. POP1 is predominantly expressed in immune tissues where it appears to inhibit NF-κB- and surprisingly enhances caspase-1-activation. Other genes encoding Pyrin-only proteins have been found in the genomes of Capripoxviridae, Leporipoxviridae, Suipoxviridae, and Yatapoxviridae. Recently, Johnston et al. reported that M13L-PYD (a Pyrin-only protein) from myxoma virus inhibits both NF-κB activity and Caspase-1-dependent IL-1b production and M13L deletion was sufficient to inhibit virus replication in vivo. (Johnston, J. B., et al. A poxvirus-encoded pyrin domain protein interacts with ASC-1 to inhibit host inflammatory and apoptotic responses to infection. Immunity 23:587). Therefore, PYDs have an active role as suppressors of host immunity. Modulating NF-κB signaling pathways is one potential mechanism for such suppression.
The completion of the human genome and the sequencing of the genomes of other species have resulted in the emergence of novel genes and the identification of new gene families. The recently described CLR family encompasses PYD-proteins with roles in both innate and acquired immunity. Because of our interest in this gene family, we sought to identify new PYD-encoding genes.

POP2: NKκB-inhibiting polypeptides, nucleic acids and methods of use


The present disclosure provides a screenshot method for an information interaction interface, including: detecting a screenshot operation; acquiring information corresponding to the information interaction interface in response to the screenshot operation, wherein the information corresponding to the information interaction interface includes at least one piece of display information currently displayed in the information interaction interface; displaying an editing interface including at least one piece of editable information, wherein each piece of editable information corresponds to one piece of display information; and editing display content of the editing interface in response to an operation on the editing interface to generate a final display picture including at least the edited display content. In addition, the present disclosure also provides a screenshot apparatus for an information interaction interface, a computing device, and a computer-readable storage medium.

With the continuous development of electronic technology, a terminal device has more and more functions. When running social applications such as WeChat and QQ, users often take screenshots of information interaction interfaces, such as dialogue interfaces, to share information, such as dialogue information. This method is relatively convenient and quick to operate, so it has been widely used. However, when taking a screenshot of the dialogue interface, the screenshot picture will include all the dialogue content in the current dialogue interface. Therefore, on the one hand, the valuable dialogue information to be shared is often discontinuous, especially for a group chat dialogue interface, which often includes irrelevant dialogue information, worthless dialogue information, and information that cannot be seen by others, so it is inevitable that there will be interference or leakage of information. On the other hand, the valuable dialogue information to be shared often cannot appear in one dialogue interface, which makes it necessary to take screenshots twice or more times, resulting in a decrease in the efficiency and convenience of operations.
Currently, there are two main ways to remove dialogue information from the screenshot pictures of the dialogue interface of social applications: the first way is to take a screenshot of the dialogue interface first, and then edit the screenshot picture through an image editing software to delete or smear some dialogue information in the screenshot picture; the second way is to delete some dialogue information in the dialogue record first, and then take a screenshot. However, the above two ways have their own problems: the problem of the first way is mainly that it requires the help of an image editing software, such that the operation efficiency and convenience are not high, and the integration of valuable dialogue information cannot be achieved; the main problem of the second way is that it may cause the original dialogue record in the social application to be lost.

Screenshot method and apparatus for information interaction interface, computing device and storage medium


In a cleaning step of a substrate-processing device, vacuum drawing is made for the space between an inner chamber and an outer chamber that receives the inner chamber. Temperature of the inner chamber is set higher than the temperature of the inner chamber during substrate processing and set lower than the temperature of a substrate support member. After that, a cleaning gas containing hexafluoroacetylaceton (Hhfac) is supplied in the inner chamber, and substances to be cleaned off adhering inside the inner chamber are removed.

Conventionally, as a film forming apparatus to form a film on a surface of a semiconductor substrate, e.g., a silicon wafer (hereinafter, referred to as wafer for simplicity), there has been known the film forming apparatus which forms a film chemically (refer to Japanese Patent Laid-Open Application No. 2002-151489). However, when the film is formed on the wafer continuously by using the film forming apparatus above-described, there is a problem that a deposit which is adhered to an inner wall of the chamber, a susceptor installed in the chamber and the like is separated from the inner wall of the chamber and the susceptor, thereby polluting the wafer.
Consequently, it is needed to clean the film forming apparatus periodically. However, there are still the drawbacks that conditions for the cleaning are not established such that the cleaning thereof is not performed efficiently.

Method of cleaning substrate-processing device and substrate-processing device


The present invention provides a method and apparatus for helping a user form a structured diagram from an unstructured information source. Starting with one or more key information elements such as some special words, the requests of a customer contained in the information source can be obtained by performing interactive and iterative searching in the unstructured information source such as text, audio, video and etc., the artifacts representing them are drawn in the diagram, and linkages are established between the artifacts and the corresponding contents in the information source. The present invention also proposes that the distribution of established linkages can be used to check whether all the requests in the information source have been extracted in the diagram. Further, various levels of warnings can be shown according to the density of linkage distribution. Therefore the user can draw a structured diagram more conveniently and quickly, and can perform checking and reusing more easily.

1. Field of the Invention
The present invention relates to a method and apparatus for helping user form a structured diagram from unstructured information source, wherein at least one artifact is formed in the structured diagram to represent at least one information element included in the unstructured information source, the information element being the objects or the interactive relations among the objects, involved in the unstructured information source.
2. Description of the Prior Art
Nowadays, visualization plays a critical role in a process for concisely and precisely describing a system. Usually, when people want to design a new system, they may start with collecting necessary information and knowledge in the form of text, audio or video. After finishing this phase, they need to set up the architecture of the system in a form of diagrams, such as modeling, sitemap, blueprint etc, as the basis for further development work, in which the essence of this system is most clearly displayed. This procedure is of particular importance to those large and complex systems. It is an important issue of system design to help people develop formal, structured diagrams from informal, unstructured information.
Taking IT architecture design as an example, there are already several formally defined diagrams to describe different aspects of a to-be-built IT system. In the case of using UML (Unified Modeling Language), there are class, object, use case, sequence, collaboration, state chart, activity component, and deployment diagram etc. A system architect develops these diagrams based on customer requirements which are normally present in text form (interview record, files provided by customer etc). There are already some tooling software to facilitate architects to generate these diagrams now. AWB (Architect's Workbench) is an example of such tooling software which is currently available. By reading and analyzing the text description in the AWB environment, the software helps an architect identify various artifacts like actor, use case etc. and build linkages between artifacts in the diagrams and their counterparts in the text files.
However, in an AWB practice, it is tedious and time consuming to read every word in the document, and then to go through the manual process to create various artifacts. It is a hard work especially for large and complex systems, since there might be hundreds or thousands pages of text for the architects to read.
Therefore, what is needed is a method and apparatus for more efficiently helping a user form a structured diagram conveniently and quickly from unstructured information source.

Method and apparatus for helping user form structured diagram from unstructured information source

International Business Machines Corporation


Planarization of a dielectric interlayer containing a dielectric gap filled layer is improved and facilitated by selective etching to reduce or eliminate steps in the gap filled dielectric layer before oxide deposition and polishing. Embodiments include gap filling a patterned metal layer with SOG or HSQ, forming a photoresist mask with an opening over steps having a height greater than about 3,000 .ANG., etching to reduce the height of the step by at least 70% depositing silicon oxide derived from TEOS or silane by PECVD and CMP.

The escalating demands for high densification and performance associated with ultra large scale integration semiconductor devices require design features of 0.25 microns and under, such as about 0.18 microns, increased transistor and circuit speeds, high reliability and increased production throughput for economic competitiveness. The reduction of design features to 0.25 microns and under challenges the limitations of conventional methodology, particularly conventional photolithographic and polishing techniques.
Conventional methodology for forming patterned metal layers comprises a subtractive etching or etch back step as the primary metal patterning technique. Such a method involves the formation of a first dielectric layer on a semiconductor substrate, typically appropriately doped monocrystalline silicon, with conductive contacts formed therein for electrical connection with an active region on the semiconductor substrate, such as a source/drain region. A metal layer is deposited on the first dielectric layer. The metal layer is typically a composite comprising a first metal layer such as tungsten or titanium, a second intermediate primary metal layer such as aluminum or an aluminum alloy, and an upper anti-reflective coating which also serves as an etch stop layer such as titanium nitride. A photoresist mask is formed on the metal layer having a pattern defining a plurality of conductive features in accordance with design requirements. The metal layer is then etched through the photoresist mask to form the conductive pattern comprising metal features separated by gaps, such as a plurality of metal lines with interwiring spacings therebetween. A dielectric layer, such as spin on glass (SOG) is then applied to the resulting conductive pattern to fill the gaps. Another dielectric layer is then deposited, such as silicon oxide derived from tetraethyl orthosilicate (TEOS) or silane by plasma enhanced chemical vapor deposition (PECVD). Planarization is then effected, as by etching or chemical mechanical polishing (CMP).
The conductive pattern typically comprises a plurality of metal features, some of which have different sizes. For example, a typical conductive pattern comprises a dense array of metal features, typically separated by gaps having a width of less than about 1 micron, e.g., about 0.375 microns for metal features of about 0.25 microns. A metal feature neighboring a leading or trailing metal feature of a dense array, however, may be considerably larger than the metal features of the dense array. For example, neighboring metal features may have an upper surface area greater than the upper surface area of a leading or trailing metal feature of a dense array such that, upon depositing a gap filling dielectric layer, a step is formed with increasing height between the relatively smaller leading or trailing metal feature and the relatively larger neighboring metal feature. Such steps can have a height in excess 3,000 .ANG. and may be as high as 1 micron or greater. It is extremely difficult to planarize an oxide layer deposited on such steps.
Moreover, as feature sizes shrink to 0.25 microns and under, planarization becomes even more critical in that irregular topography may exceed the depth of focus limitations of conventional photolithographic techniques. Accordingly, as design features shrink to 0.25 microns, it becomes increasing critical to minimize or reduce the formation of steps when gap filling patterned conductive layers.
There exists a need for semiconductor methodology for improved planarization of dielectric layers. There exists an even greater need for improved planarization of dielectric layers in manufacturing semiconductor devices having a feature size of about 0.25 microns or under.

Selective etching for improved dielectric interlayer planarization