A system and method is discussed for providing programmable test conditions for a built-in self test circuit of a flash memory device. The present invention employs a flash memory having BIST circuit for testing the memory and a BIST interface circuit adapted to adjust the test conditions of the memory tests. The BIST interface circuit is operable to receive one or more global variables associated with the test conditions of a plurality of tests used on the flash memory and to output results of the memory tests based on the value of the variables. The global variables are used to adjust the test conditions and to trim one or more references used in various flash memory tests and operations. The system may further include a serial communications medium for communicating the global variables to the BIST interface and test results from the interface.

Improvements in semiconductor processes are making possible integrated circuits of increasing size and complexity. The semiconductor processing technologies that produce these integrated circuits have advanced to the point where complete systems, including memories, can now be reduced to a single integrated circuit or application specific integrated circuit (ASIC) device. These integrated circuits (also referred to as "die" or "chips") may use many functions that previously could not be implemented on a single die. It is a common practice for the manufacturers of such integrated circuits to thoroughly test device functionality at the manufacturing site. However, due to the complex nature of today's integrated circuits and an attendant sensitivity to variations in manufacturing processes, manufacturers are constantly confronted with new testing challenges.
Before manufacturers release integrated circuits for shipment, the devices typically undergo a variety of testing procedures. In ASIC devices incorporating integrated memories, for example, specific tests are performed to verify that each of the memory cells within the integrated memory array(s) is functioning properly. This testing is necessary because perfect yields are difficult to achieve. It is not uncommon for a certain percentage of unpackaged ASIC die to contain memory cells which fail testing processes, due largely to non-systemic manufacturing defects. Such manufacturing issues are likely to increase as process geometries continue to shrink and the density of memory cells increases. Even today, up to 1 Gbits or more of dynamic random access memory (DRAM), static random access memory (SRAM) or flash memory can be integrated onto a single integrated circuit.
A number of ASIC memory testing strategies have evolved, many of which involve use of an external memory tester or Automated Test Equipment (ATE). If memory is accessible from input/output (I/O) pins, a hardware test mode can be utilized. In this mode, a production test system accesses the memory directly by writing to and reading from the memory bits. The main disadvantage of using such standard test modes is that the test system must test the devices interactively. Consequently, only a limited number of devices can be tested at a given time, and a significant amount of overhead time is incurred due to tester limitations (e.g., power up time is needed on certain pins while the mode is being accessed and while the tester is controlling the chip and checking the results).
If an embedded memory is embedded within an ASIC, built-in self-test (BIST) is often considered the most practical and efficient test methodology and is becoming increasingly popular with semiconductor vendors. BIST allows timely testing of the memory with a reasonably high degree of fault coverage, without requiring continual interactive (sequential) control via external test equipment.
BIST refers in general to any test technique in which the testing algorithm or test vectors are generated internal to a discrete memory, an integrated circuit, or ASIC device. The testing algorithm used in BIST may be generally implemented in embedded circuitry of the device. Test vectors are sequences of signals that are applied to integrated circuitry to determine if the integrated circuitry is performing as designed. BIST can be used to test these memories located anywhere on the device.
In the BIST approach, a test pattern generator and test response analyzer are incorporated directly into the device to be tested. BIST operation is controlled by supplying an external clock and via use of a simple commencement protocol. BIST testing is typically distilled to the level of a "passed" or "failed" result. At the end of a typical structured BIST test, or "run", a simple pass/fail signal is asserted, indicating whether the device passed or failed the test. Intermediate pass/fail signals may also be provided, allowing individual memory locations or group of locations to be analyzed.
Unlike external testing approaches, at-speed testing with BIST is readily achieved. BIST also alleviates the need for long and convoluted test vectors and may function as a surrogate for functional testing or scan testing. Since the BIST structures exist and remain active throughout the life of the device, BIST can be employed at the board or system level to yield reduced system testing costs, reduce device rejects during production, and to reduce field diagnosis costs.
Many different types and styles of memory exist to store data for computers and similar type systems, wherein BIST circuits may be implemented. For example, random access memory (RAM), dynamic random access memory (DRAM), static random access memory (SRAM), read only memory (ROM), programmable read only memory (PROM), electrically programmable read only memory (EPROM), electrically erasable programmable read only memory (EEPROM) and flash memory are all presently available to accommodate data storage. Each type of memory has its own particular advantages and disadvantages.
Flash memory has become a popular type of memory because it combines the advantages of the high density and low cost of EPROM with the electrical erasability of EEPROM. Flash memory can be rewritten and can hold its contents without power, and thus is nonvolatile and is suitable for BIST circuitry and testing methods. Flash memory is used in many portable electronic products, such as cell phones, portable computers, voice recorders, etc. as well as in many larger electronic systems, such as cars, planes, industrial control systems, etc.
Individual memory cells are organized into individually addressable units or groups, which are accessed for read, program, or erase operations through address decoding circuitry. The individual memory cells are typically comprised of a semiconductor structure adapted for storing a bit of data and includes appropriate decoding and group selection circuitry, as well as circuitry to provide bias and reference voltages and currents to the cells being operated upon. Carefully trimming or controlling such bias and reference voltages is essential to proper memory operations, but requires considerable test time if conventional testers are used to test devices which do not have BIST.
The erase, program, and read operations are commonly performed by application of appropriate voltages to certain terminals of the memory cell. In an erase or write operation the voltages are applied so as to cause a charge to be removed or stored in the memory cell. In a read operation, appropriate voltages are applied so as to cause a current to flow in the cell, wherein the amount of such current is indicative of the value of the data stored in the cell. The memory device includes appropriate circuitry to sense the resulting cell current in order to determine the data stored therein, which is then provided to data bus terminals of the device for access by other devices in a system in which the memory device is employed.
In a NOR configuration, the control gate is connected to a wordline associated with a row of memory cells to form sectors of such cells. In addition, the drain regions of the cells along a given column are connected together by a conductive bitline. Respective flash cells associated with a given bitline have stacked gate terminals coupled to a different wordline, while all the flash cells in the array generally have their source terminals coupled to a common source terminal. In operation, individual flash cells are addressed via the respective bitline and wordline using the peripheral decoder and control circuitry for programming (writing), reading or erasing functions.
Programming circuitry controls a bit of a cell by applying a signal to the wordline, which acts as a control gate, and changing bitline connections such that the bit is stored by the source and drain connections. Erasing is performed as a blanket operation wherein an array or sector of cells can be simultaneously erased. Generally, a gate voltage is applied to the control gates via the wordline(s) and a drain voltage is applied to the drains via the bitlines, while the sources may be configured to float.
In the blanket erasing of flash memory, cells within an array or sector are typically erased concurrently and can be accomplished by one or more applications of short erase pulses. After each erase pulse, an erase verification can be performed to determine if each cell in the array is now "erased" (blank), or yet remains "un-erased" or "under-erased", (i.e., whether the cell has a threshold voltage above a predetermined limit). If an under-erased cell is detected, an additional erase pulse can be applied to the entire array. With such an erase procedure, however, cells that are sufficiently erased initially will also be repeatedly erased, leading to some cells becoming "over-erased" before other cells are sufficiently erased. A memory cell having a threshold voltage erased below a predetermined limit is commonly referred to as being over-erased. An over-erased condition is undesirable for many reasons.
In addition, testing algorithms used in BIST often attempt to determine a representative group of memory cells associated with a representative erase threshold level, by selecting edge columns, edge rows, or diagonal groupings of memory cells representative of the entire sector or array. Each grouping selection has a unique advantage, attempting to provide the representative erase level or a corresponding representative number of erase pulses required. Regardless of the grouping selected, however, a truly representative erase threshold level for the sector or array of memory cells is elusive, as differences exist between memory arrays and/or the particular ASIC application wherein the array resides. Further, the aforementioned grouping choices may not be sufficiently representative of the desired erase threshold level, and also may be difficult to implement in BIST circuitry.
As a result of the aforementioned tests required by BIST, implementing such test choices, voltages, and other variations in BIST circuitry traditionally requires mask changes that may be prohibitively expensive and time consuming.
Thus, as device scaling trends continue, there is a desire to improve on the capabilities and flexibility of BIST, while minimizing the design complexity and real estate required of BIST circuitry. Accordingly, a need exists for a method of adjusting the test conditions of BIST tests implemented in BIST circuits for self testing a flash memory device.

Input of test conditions and output generation for built-in self test


A method and apparatus for etching material layers with high uniformity of a lateral etch rate across a substrate using a gas mixture that includes a passivation gas. The passivation gas is provided to a peripheral region of the substrate to passivate sidewalls of the structures being etched.

1. Field of the Invention
The present invention generally relates to a method and apparatus for fabricating devices on semiconductor substrates. More specifically, the present invention relates to a method and apparatus for performing an etch process in a semiconductor substrate processing system.
2. Description of the Related Art
Ultra-large-scale integrated (ULSI) circuits may include more than one million micro-electronic devices (e.g., transistors, capacitors, and the like) that are formed on a substrate (e.g., silicon (Si) wafer) and cooperate to perform various functions within the device. Manufacture of ULSI circuits generally comprises processes where one or more material layers of a film stack on the substrate are etched (e.g., plasma etched) to form structures of the devices being fabricated.
One problem associated with a conventional etch process is the non-uniformity of a lateral etch rate across the substrate due to a substrate edge effect. Herein lateral etch rate non-uniformity is defined as a ratio of a difference between the maximal and minimal lateral etch rate to the sum of such values across the substrate. More specifically, the lateral etch rate at peripheral locations (i.e., near an edge of the substrate) is higher than the lateral etch rate near a center of the substrate. Non-uniformity in the lateral etch rate results in non-uniformity in the critical dimensions of the structures formed by the etch process.
During the etch process, non-volatile by-products passivate sidewalls of the structures being formed and, as such, reduce the etch rate. Non-uniformity of the etch rate across the substrate is caused by a higher concentration of the by-products near the center of the substrate than in the peripheral region. In operation, a concentric pattern of exhaust pumping in the etch process chamber results in a low concentration of the by-products near the edge of the substrate and, correspondingly, in a high local lateral etch rate.
Structures being formed using the conventional etch process are typically over-etched in the peripheral region that may extend about 10-20 mm from the edge of the substrate. Such a region represents approximately 19-36% and 13-25% of usable real estate for the 200 mm and 300 mm substrate, respectively. A loss of accuracy for topographic dimensions (e.g., critical dimensions (CDs), or smallest widths) of the etched structures in the peripheral regions of the substrates may significantly affect performance and increase costs of fabricating the integrated circuits and micro-electronic devices.
Therefore, there is a need in the art for an improved method for etching material layers with high uniformity of a lateral etch rate across a substrate in manufacture of micro-electronic devices.

Method and apparatus for etching material layers with high uniformity of a lateral etch rate across a substrate


A zoom lens system consists, in order from an object side to an image-forming side, of a first negative lens group G1, a second positive lens group G2, and a third positive lens group G3. The first lens group G1 consists of one negative lens and one positive lens, the second lens group G2 consists of a cemented lens composed of a positive lens and a negative lens, and one meniscus lens that is concave on the image-forming side, the third lens group G3 consists of a single positive lens, and a combined focal length f2 of the second lens group, a focal length Lf23 of the meniscus lens of the second lens group, a combined focal length fw of the zoom lens system at a wide angle end, a combined focal length f3 of the third lens group, a radius of curvature Ro of an object side surface of the positive lens in the cemented lens, and a radius of curvature Ri of an image-forming side surface of the positive lens in the cemented lens satisfy the following conditions0<|f2/Lf23|<0.3−2.0<Ri/Ro<−1.00.25<fw/f3<0.45.

The present invention relates to a zoom lens system that is suited to mounting in a digital camera or an information terminal such as a mobile phone that is equipped with a digital camera function.
A digital camera that uses an image pickup device such as a CCD or a CMOS to obtain an image formed by a lens as digital data is known. An information terminal such as a mobile telephone, a cellular phone etc., in which a digital camera is incorporated is also known.
Japanese Laid-Open Patent Publication No. 2001-296476 discloses a zoom lens composed of three lens groups with negative, positive and positive refractive powers in that order from the object side, where the first group consists of two lenses, the second group consists of four lenses, and the third group consists of one lens, making a total of seven lenses. To make such zoom lens systems even more compact, there is demand for a further reduction in the number of lenses that construct the lens system.


A method of manufacturing a semiconductor film capable of inhibiting the quality of a semiconductor film from destabilization is obtained. This method of manufacturing a semiconductor film includes steps of introducing source gas for a semiconductor, controlling the pressure of an atmosphere formed by the source gas to a prescribed level, heating a catalytic wire to at least a prescribed temperature after controlling the pressure of the atmosphere to the prescribed level and forming a semiconductor film by decomposing the source gas with the heated catalytic wire.

1. Field of the Invention
The present invention relates to a method of manufacturing a semiconductor film and a method of manufacturing a photovoltaic element, and more particularly, it relates to a method of manufacturing a semiconductor film and a method of manufacturing a photovoltaic element each comprising a step of forming a semiconductor film by decomposing source gas with a catalytic wire.
2. Description of the Background Art
A method of manufacturing a semiconductor film comprising a step of forming a semiconductor film by decomposing source gas with a catalytic wire is known in general, as disclosed in Japanese Patent No. 3453214, for example.
According to the aforementioned Japanese Patent No. 3453214, a gas mixture of gas (source gas) of a silicon compound such as silane (SiH4) and gas of another material such as hydrogen (H2) is introduced into a catalytic body (catalytic wire) supplied with power to be heated to at least the thermal decomposition temperature of the source gas, thereby decomposing the silicon compound and forming a silicon film (semiconductor film) on the surface of a substrate.
However, the aforementioned Japanese Patent No. 3453214 discloses neither the timing for starting supplying power to (starting heating) the catalytic body (catalytic wire) nor the timing for introducing the source gas in formation of the silicon film (semiconductor film). In general, heating of the catalytic body is started and the source gas is introduced at the same time. In this case, a constant time is required for stabilizing the pressure of an atmosphere formed by the source gas after the introduction of the source gas, and hence the semiconductor film is formed in a state where the pressure of the atmosphere formed by the source gas is not yet stabilized in the initial state. In this case, the quality of the semiconductor film formed in the state where the pressure of the atmosphere formed by the source gas is not yet stabilized is disadvantageously destabilized.

Method of manufacturing semiconductor film and method of manufacturing photovoltaic element


An improved structure of a chip socket is composed of a chip socket which is a square fixing seat, and a center of the fixing seat is provided with a cavity for holding a chip. Inner sides of the cavity are arranged with insertion slots for terminals, the cavity of fixing seat is provided with a fixing plate, and a side of the fixing plate is extended and arranged with insertion slots which are corresponding to pins of the terminals.

a) Field of the Invention
The present invention relates to a chip socket structure, and more particularly to a chip socket structure wherein insertion slots of a fixing plate are corresponding to terminals, such that when pins of the terminals are correspondingly inserted into the insertion slots of fixing plate, they can be tidily arranged inside the insertion slots.
b) Description of the Prior Art
Referring to FIG. 1 and FIG. 2, a center of conventional chip socket A is provided with a cavity A2 for holding a chip A2, and peripheries of the cavity A2 are arranged with insertion slots A4 for terminals A3 which are connected with each pin A6 with connection plates A5. After the chip A2 is implanted, the connection plates A5 are broken off to separate the pins A6 from one another, and the pins A6 are extended in an approximately horizontal direction to form a suspension state at insertion parts A7. Therefore, after the chip socket A are assembled, the pins A6 are easy to form an irregular configuration, such that when a surface mounting technology is applied to weld the chip socket A on a circuit board, the pins A6 cannot be fixed horizontally and a void solder phenomenon is formed.
Accordingly, how to eliminate the aforementioned drawbacks is a technical issue to be solved by the inventor of present invention.

Abstract: Through the correspondence of insertion slots of the fixing plate to the terminals at insertion slots, the pins of terminals can be tidily arranged inside the insertion slots, such that the pins can be maintained at a horizontal direction and there will be no void solder phenomenon caused by welding the pins, when the chip socket is welded with a surface mounting technology.


Silicon infiltration technology, e.g., siliconizing or reaction-bonding, is used to produce ceramic-rich composite bodies having utility as ballistic armor. In the main embodiment of the invention, the ballistic armor includes a reaction-bonded silicon carbide body (RBSC). Good ballistic performance can be advanced by loading the porous mass or preform to be infiltrated to a high degree with one or more hard fillers, and by limiting the size of the morphological features making up the composite body. This control of “grain size” can be accomplished by controlling the size of the largest particles making up the porous mass to be infiltrated, but also of importance is controlling the processing conditions, particularly by controlling the factors that cause grain growth, coarsening of microstructure, and/or grain coalescence.

1. Field of the Invention
This invention relates to ballistic armor structures produced using silicon infiltration technology. More particularly, the invention relates to infiltration techniques to form ceramic-rich composite armor bodies, e.g., reaction-bonded silicon-carbide bodies.
2. Discussion of Related Art
In many armor applications, weight is not a critical factor, and traditional materials such as steel can offer some level of protection from airborne kinetic energy threats such as ballistic projectiles and shell fragments. Steel armors offer the advantage of low cost and the fact that they also can serve as structural members of the equipment into which they are incorporated. In recent decades, certain hard ceramic materials have been developed for certain armor applications. These ceramic-based armors, such as alumina, boron carbide and silicon carbide provide the advantage of being lighter in mass than steel for the same level of protection. Thus, in applications in which having an armor having the lowest possible mass is important, such as (human) body armor and aircraft armor, low specific gravity armor materials are called for. The lower the density, the greater the thickness of armor that can be provided for the same areal density. In general, a thick armor material is more desirable than a thinner one because a greater volume of the armor material can be engaged in attempting to defeat the incoming projectile. Moreover, the impact of the projectile on a thicker armor plate results in less tensile stress on the face of the plate opposite that of the impact than that which would develop on the back face of a thinner armor plate. Thus, where brittle materials like ceramics are concerned, it is important to try to prevent brittle fracture due to excessive tensile stresses on the back face of the armor body; otherwise, the armor is too easily defeated. Rather, by preventing such tensile fracture, the kinetic energy of the projectile perhaps can be absorbed completely within the armor body, which energy absorption manifests itself as the creation of a very large new surface area of the armor material in the form of a multitude of fractures, e.g., shattering.
U.S. Pat. No. 5,372,978 to Ezis discloses a projectile-resistant armor consisting predominantly of silicon carbide and made by a hot pressing technique. Up to about 3 percent by weight of aluminum nitride may be added as a densification aid. The finished product features a microstructure having an optimal grain size of less than about 7 microns. Fracture is intergranular, indicating energy-absorbing crack deflection. Moreover, the economics of manufacturing are enhanced because less expensive, less pure grades of silicon carbide can be used without compromising the structural integrity of the material.
U.S. Pat. No. 4,604,249 to Lihleich et al. discloses a composition particularly suited for armoring vehicles. The composition is a composite of silicon carbide and steel or steel alloy. Silicon and carbon particulates, optionally including silicon carbide particulates, are mixed with an organic binder and then molded to form a green body. The green body is then coked at a maximum temperature in the range of about 800° C. to about 1000° C. The temperature is then rapidly raised to the range of about 1400° C. to about 1600° C. under an inert atmosphere of at least one bar pressure. In this temperature range, the silicon and carbon react to form silicon carbide, thereby producing a porous body. The pores are then evacuated in a vacuum chamber, and the body is immersed in molten steel or steel alloy. The metal fills up the pores to produce a dense composite armor material.
U.S. Pat. No. 3,725,015 to Weaver discloses composite refractory articles that, among other applications, have utility as an armor material for protection against penetration by ballistic projectiles. These compositions are prepared by cold pressing a mixture of a powdery refractory material and about 10 to 35 parts by volume of a carbon containing substance, such as an organic binder material or elemental carbon to form a preform, heat-treating the preform to convert the carbonaceous material to carbon, and then contacting the heated preform with a molten metal bath, the bath containing at least two metals and maintained at a temperature between 1700° C. and 1900° C. The molten metal infiltrates the preform, the refractory material matrix sinters and at least one of the metallic constituents reacts with the carbon to produce a metal carbide. Because the thermal expansion coefficient of the metal mixture is close to or slightly greater than that of the refractory matrix, the composite shape cools to room temperature essentially free of cracks and residual stress. Weaver states that, while there are no rigid particle size parameters except those dictated by the properties desired in the final product, a maximum size of about 350 microns for the particles of the powdered materials that make up the mixture to be pressed is preferred.
U.S. Pat. No. 3,796,564 to Taylor et al. discloses a hard, dense carbide composite ceramic material particularly intended as ceramic armor. Granular boron carbide is mixed with a binder, shaped as a preform, and rigidized. Then the preform is thermally processed in an inert atmosphere with a controlled amount of molten silicon in a temperature range of about 1500° C. to about 2200° C., whereupon the molten silicon infiltrates the preform and reacts with some of the boron carbide. For armor applications, Taylor places a limit of 300 microns as the maximum size for the granular boron carbide component. The formed body comprises boron carbide, silicon carbide and silicon. Taylor states that such composite bodies may be quite suitable as armor for protection against low caliber, low velocity projectiles, even if they lack the optimum properties required for protection against high caliber, high velocity projectiles.
U.S. Pat. No. 3,857,744 to Moss discloses a method for manufacturing composite articles comprising boron carbide. Specifically, a compact comprising a uniform mixture of boron carbide particulate and a temporary binder is cold pressed. Moss states that the size of the boron carbide particulate is not critical; that any size ranging from 600 grit to 120 grit may be used. The compact is heated to a temperature in the range of about 1450° C. to about 1550° C., where it is infiltrated by molten silicon. The binder is removed in the early stages of the heating operation. The silicon impregnated boron carbide body may then be bonded to an organic resin backing material to produce an armor plate.
U.S. Pat. No. 3,859,399 to Bailey discloses infiltrating a compact comprising titanium diboride and boron carbide with molten silicon at a temperature of about 1475° C. The compact further comprises a temporary binder that, optionally, is carbonizable. Although the titanium diboride remains substantially unaffected, the molten silicon reacts with at least some of the boron carbide to produce some silicon carbide in situ. The boron carbide filler is generally limited to about 150 microns in size, but since the titanium diboride component does not appear to react with the silicon under the local process conditions, there is no critical upper limit of its particle size. When certain shaping techniques such as extrusion are employed, however, it is often desirable to limit the particle size to about 125 microns or less. The flexural strength of the resulting composite body was relatively modest at about 140 MPa. A variety of applications are disclosed, including personnel, vehicular and aircraft armor.
Each of the above-described armor inventions suffers from one shortcoming or another. Hot pressing is expensive and shape-limited. Hot pressed or sintered ceramics do not hold dimensional tolerances as well as reaction-bonded silicon carbide ("RBSC"). Iron matrix composite materials are heavy in relation to ceramic armors. An infiltration temperature of 2200° C. is too high, and will likely result in exaggerated grain growth. A preform containing 35 volume percent of reactable carbon will yield excessive amounts of in-situ SiC.
As the preceding synopsis of the patent literature indicates, reaction-bonded or reaction-formed silicon carbide has been proposed and evaluated as a candidate armor material as long ago as the 1960's.
In the Third TACOM Armor Coordinating Conference in 1987, Viechnicki et al. reported on the ballistic testing of a RBSC material versus sintered and hot pressed silicon carbide materials. Not only was the RBSC substantially inferior to the other silicon carbides, Viechnicki et al. came to the general conclusion that purer, monolithic ceramics with minimal amounts of second phases and porosity have better ballistic performance than multiphase and composite ceramics. (D. J. Viechnicki, W. Blumenthal, M. Slavin, C. Tracy, and H. Skeele, "Armor Ceramics—1987," Proc. Third TACOM Armor Coordinating Conference, Monterey, Calif. (U.S. Tank-Automotive Command, Warren, Mich., 1987) pp. 27-53).
Accordingly, in spite of the price advantage of RBSC relative to sintered or hot pressed silicon carbide, what the market has preferred has been a sintered or hot pressed monolithic ceramic product. As of the beginning of the year 2000, there was little or no RBSC armor on the market.
The details of a ballistic impact event are complex. One widely held theory of defeating a ballistic projectile is that the armor should be capable of fracturing the projectile, and then erode it before it penetrates the armor. Thus, compressive strength and hardness of a candidate armor material should be important. The above-mentioned armor patent to Taylor discloses a modulus of rupture as high as 260 MPa, and furthermore states that for armor applications the strength should be at least 200 MPa.
There seems to be a consensus in the armor development community that hardness is indeed important in a candidate armor material, and in particular, that the hardness of the armor should be at least as great as the hardness of the projectile. As for the strength parameter, however, those testing armor materials have had a difficult time correlating mechanical strength (both tensile and compressive) with ballistic performance. In fact, except for hardness, there is no single static property that is a good predictor of good armor characteristics in ceramic materials. Instead, the guidance that has been provided from the armor developers to the materials developers based upon actual ballistic tests has been that candidate armors in general should possess a combination of high hardness, high elastic modulus, low Poisson's ratio and low porosity. (Viechnicki et al., p. 32-33)
U.S. Pat. No. 5,205,970 to Brun et al. discloses a method for making silicon carbide bodies having improved surface finish. In particular, reaction-bonded or reaction-formed silicon carbide bodies are produced by reactively infiltrating silicon into a porous carbonaceous preform to form a silicon carbide body. Excess infiltrant is provided to provide for complete infiltration and filling of porosity in the preform. After infiltration, the excess infiltrant appears as excess droplets on the surface of the reaction-formed body. The formed body is then placed in contact with a wicking means, such as a piece of carbon cloth and re-heated above the infiltrant melting temperature. Excess infiltrant is wicked from the surface of the body into the wicking means by capillary force. Moreover, the wicking means is readily removed from the formed body, as the excess infiltrant that had previously bonded the wicking means to the body has been removed. Any residual wicking means material remaining on the reaction-formed body can be removed by light grinding or diamond polishing.
Another patent to Weaver, namely U.S. Pat. No. 4,019,913, discloses a method for making a high strength RBSC body. Specifically, about 3 micron diameter silicon carbide powder was roll mixed with about 18 percent by weight of colloidal graphite and distilled water. After drying and screening, a tile was cold pressed to yield a silicon carbide filler loading of about 52-53 percent by volume. The preform tile was then infiltrated with silicon at a temperature of about 2070° C. in a nitrogenous atmosphere. The resulting composite body had a final density of about 3.02 g/cc and had a flexural strength of about 530-550 MPa.
Neither Brun nor Weaver '913 advances any suggestion that their materials would be suitable armor materials.
The instant inventors have re-visited RBSC as a candidate armor material because they believe that a RBSC material can be developed whose anti-ballistic performance is competitive with other armor ceramics, such as the hot pressed armors, but at reduced cost.

Ceramic-rich composite armor, and methods for making same


A combination pressure relief and vacuum relief valve for mounting on a storage tank is disclosed as having two vertical mounting connections of different elevations; a pressure relief valve mounted on one connection; and a vacuum relief valve mounted on the other connection such that said vacuum relief valve is higher in elevation than said pressure relief valve. The valve is sanitary for use in food and pharmaceutical production and storage and has highly polished surfaces to prevent processed material from sticking. The valve also includes special sloping surfaces in the body and connections to prevent processed material from standing in the valves. The pressure valve and vacuum valve may be removed separately or rotated separately for mounting. The combination valve may be attached on storage tanks or other vessels or conduits.

1. Field of the Invention
The present invention generally relates to tank venting valves for relieving the internal pressure or vacuum in tanks at a predetermined pressure/vacuum. More particularly this invention relates to weight/spring loaded tank vents. More particularly the invention relates to tank venting valves for use in sanitary service for processing food and pharmaceuticals.
2. Related Art
The basic valve design is known as a "weight loaded tank vent". The design utilizes a weighted cover over a nozzle. The cover, also known as a pallet, forms a barrier to the nozzle opening. The weight of the pallet determines at what pressure the pallet will lift open to relieve pressure in the tank. The opening pressure is known as the "set pressure". The set pressure can easily be determined by dividing the weight of the pallet assembly by the open area of the nozzle. If a higher set pressure is desired, more weight is added to the pallet.
Another type of pressure relieving device is a spring loaded tank vent. The spring loaded type is used for set pressures above that which is practical for weight loaded operation due to either a high set pressure and there is not enough room for the weights on the pallet or where the size of the vent nozzle dictates a large weight on the pallet.
A third type of tank vent is pilot operated. Pilot operated tank vents utilize the tank pressure acting on an area larger than the nozzle area to create a higher downward force to hold down a pallet or seat plate against the tank pressure. For this reason pilot operated tank vents seal tighter than weight or spring loaded vents until the set or opening pressure is reached. The set pressure is adjustable by means of a spring in the pilot.


A recording and reproducing system for digitizing the image signal and compression coding the signal by in-field and inter-field, or in-frame and inter-frame coding, wherein the inter-field or inter-frame coding is used as the primary coding method, in field or in-frame coding is applied at a regular interval, and when scene changes are detected, in-field or in-frame coding is mandatorily applied to the field or frame immediately after the scene change. Furthermore, a new in-field or in-frame coding cycle is started at the field or frame immediately after the scene change to absorb the increased information resulting from in-field or in-frame coding by increasing the compression ratio of the inter-field or inter-frame coding means within the period to the next in-field or in-frame coded field or frame. The generation of additional information is further reduced and the increase in information produced by the field or frame immediately after the scene change is absorbed by a data substitution, specifically by absorbing the increase in information generated by the field or frame immediately after the scene change by using the same data as that of the immediately preceding field or frame for the field or frame immediately before or after the scene change.

1. Field of the Invention
The present invention relates to a signal processing method for bandwidth compression coding of an image signal, and to a recording and reproducing device for recording this information to a recording medium such as an optical disk or a video tape and reproducing the information from this medium.
2. Prior art
Known image signal compression coding methods include in-field, in-frame, inter-field, and inter-frame. Inter-field and inter-frame coding use the correlation between the current field or frame and the fields or frames chronologically before and after the current field or frame to achieve a generally high compression ratio compared with in-field or in-frame compression coding, but requires in-frame or in-field coding to refresh the signal at a regular period because errors, when they occur, are propagated along the time axis.
During scene changes, however, when there is a significant change in the image, there is no time axis correlation between the adjacent fields or frames. Inter-field or inter-frame coding is therefore meaningless, and can actually result in image deterioration under certain circumstances.
Furthermore, the total amount of compression coded information increases and the effective compression ratio therefore decreases when in-field or in-frame coding is extensively used.

Image signal recording and reproducing system with use of bandwidth compression coding

Matsushita Electric Industrial Co., Ltd.


A method for identifying a disk loaded in a digital disk player as being either a single layer disk or a dual layer disk, and for setting a predetermined servo gain with respect to reproduction from each of two signal recording layers of a dual layer disk to achieve accurate servo control. The player counts the number of S curves occurring in a focus error signal generated during a focus search, and a system controller identifies the disk as being a dual layer disk or a single layer disk on the basis of the number of S curves or, alternatively, on the basis of the amplitude of the focus error signal. After a dual layer disk loaded in the player, the system controller determines servo gain coefficients with respect to first and second signal recording layers of the disk on the basis of signal amplitudes read from the signal recording layers, and stores the servo gain coefficients in a memory. At the time of reproduction, the system controller controls a servo gain by setting in a gain control section the stored servo gain coefficient corresponding to a selected one of the signal recording layers from which recording data is to be reproduced.

1. Field of the Invention
The present invention relates to a digital disk player and, more particularly, to a digital disk player which reproduces a record by reading from a dual layer disk having two signal recording layers or from a single layer disk having only one signal recording layer, and in which servo gain is controlled when reading from a dual layer disk.
2. Description of the Related Art
There are two types of disks for use with digital video disk (DVD) players: a single layer disk having only one signal recording layer and a dual layer disk having two signal recording layers. FIG. 4A shows the structure of a single layer disk having a signal recording layer RL, a transparent plastic layer SR (substrate) and a protective layer PL for protecting the signal layer. FIG. 4B shows the structure of a dual layer disk, which includes a dual layer structure constructed by combining two disks having signal recording layers RL1 and RL2, and transparent plastic layers (substrates) SR1 and SR2, respectively, with a spacing layer SPL interposed therebetween. In FIGS. 4A and 4B, objective lenses LS are also illustrated.
Conventional techniques for reproduction from compact disks (CDs) can be used for reproduction from single layer disks, but not from dual layer disks, because these techniques were developed without considering dual layer disk technology.
Optical disk players such as CD players, laser disk players and DVD players have a focus servo controller for converging a laser beam on a signal recording surface of a disk, and a tracking servo controller for positioning the beam at the center of a selected track formed on the signal recording surface. The focus servo controller generates a focus error signal having a voltage value which varies according to the distance between a position of an objective lens and a particular in-focus position (the position of the objective lens when the focal point of the objective lens coincides with the signal recording surface), and controls the position of the objective lens with respect to the disk so that the error signal becomes zero. The tracking servo controller generates a tracking error signal according to a deviation of the beam from the track center, and controls the beam position so that the error signal becomes zero.
It would be convenient for users if digital disk players were designed to be able to reproduce data both from single layer disks and from dual layer disks. Current digital disk players do not perform this function. Such a digital disk player design must be able to identify a disk loaded in the digital disk player as being either a single layer disk or a dual layer disk because reproduction from single layer disks and dual layer disks is based on different standards.
One type of disk read by digital disk players has a dual layer structure constructed, as shown in FIG. 7, by combining two disks having signal recording layers RL1 and RL2, respectively formed on transparent substrates SR1 and SR2, with a spacing layer SPL interposed therebetween. An objective lens LS is provided for reproduction from the disk, as shown in FIG. 7. The reflectivity of such a dual layer disk is 25 to 40%, and the first signal recording layer RL1 and the second signal recording layer RL2 have different reflectivities. The reflectivity of the first signal recording layer is smaller than that of the second signal recording layer.
Due to the different reflectivities of the first and second signal recording layers of a dual layer disk, servo error signals (focus error signal, tracking error signal) respectively reproduced from the first and second signal recording layers RL1 and RL2 differ in amplitude from each other. If the servo gain of a digital disk player is controlled by being adapted for one of the signal recording layers, then servo control cannot be performed accurately during reproduction from the other signal recording layer.


A personal defense system having a protective spray container with an upper end spray actuator, a dispensing cap constructed and arranged to house the spray actuator and have a fixed relationship with the dispensing nozzle thereof, a holster for the container having an interlocking structure with the dispensing cap to prevent relative rotation, and also including a security system releasably attached to the hoister.

1. Field of the Invention
The invention relates generally to spray dispensing canisters, and more particularly to improvements in a jacketed tear gas dispenser and security system for personal defense.
2. Prior Art
In the past, tear gas defense systems have not been either as accepted or as useful as they should be as personal defense weapons even though the term "tear gas" is almost a household word in identifying a substance or product for disabling a potential assailant or attacker, whether human, canine or otherwise. The present invention does not per se relate to any specific tear gas or other disabling formulation or to the construction of the spray canister therefor. However, it is generally known that there are two types of tear gas formulations, called "CN" and "CS", and both types employ active ingredients that effect tear glands and/or breathing and also have other ingredients such as glidants to enable dispensing from aerosol containers as a uniform and controllable spray.
For many years tear gas and like disabling products have been packaged in various forms, including pressurized aerosol canisters, for use by law enforcement officers as a "reasonable force" weapon to subdue or control suspects. This type of weapon in the hands of trained police officials is used as a substitute for guns, nightsticks or billyclubs to prevent unnecessary injuries or even fatalities while serving to immobilize suspects and prisoners. Existing spray canisters are generally designed to fire a series of 20-30 streams or sprays of tear gas fluid up to about 25 feet. Such an ejection as a fluid stream aids in aiming and ensures against "blow back" into the policeman's face.
In recent years, the use of tear gas has been widely advocated as a personal defense weapon. In the personal defense field, the carrying of protective spray devices to ward off or temporarily disable a thief, mugger or other assailant has become more common. It should be recognized that the primary danger time is at night, and generally when moving to or from the car at home, business or the like. However, an attack by a vicious dog or a would-be mugger can occur at any time, and any defense system is only as effective as the preparedness and vigilance of the individual. In the past, tear gas dispensers for personal use, despite information and training, usually become carried haphazardly in a purse or pocket or left lying in a car rather than being kept readily at hand for immediate use if needed. Heretofore, there has been no reliable system encouraging the carrying of the spray canister as a part of defense preparedness in daily living patterns.
Another problem with aerosol canisters in the past has included incidents involving the accidental or inadvertent discharge of the pressurized contents by the pushing or jamming of the actuator member against other small objects or articles, as in a purse, car glove box or the like. In fact, it is a human habit to twist and turn, push and prod and otherwise handle various objects in a purse or pocket, such as keys, change, etc. Prior tear gas canisters have been designed so that such mishandling could result in inadvertent discharge, as aforesaid, or even in a turned misalignment of the spray discharge opening or its valve actuator so that the defense product cannot be fired properly without resetting it.
U.S. Pat. No. 4,220,263 discloses a holstered aerosol container and permanently attached keyring in which the container is free to turn to a blocked position in the holster and is only capable of being actuated by pressing on a retaining strap of the holster. The device of the '263 patent prevents simultaneous use of the protective spray and the keyring. U.S. Pat. No. 3,445,046 shows a holstered aerosol container having a top actuator shielded by the holster, but accessible through a side opening although the container is capable of being turned in the hoister. U.S. Pat. No. 3,240,397 shows a spray dispenser having a guard-type actuator cap, and U.S. Pat. No. 2,940,641 shows a spray dispenser with an outer casing having a telescoping cap actuator.


Disclosed is a video display an auto-convergence error in a projection television receiver (TV) capable of preventing generation of an error when an auto-convergence is performed. The apparatus includes a screen for displaying an image signal, first to eighth sensing units having first and second optical sensors for sensing a pattern displayed on the screen, first and second amplifying units for receiving and amplifying sensed values sensed by the first to fourth sensing units and the fifth to eighth sensing units with predetermined multiple amplification factors, first and second comparators for receiving and comparing amplified values outputted from the first and second amplifying units, an inverter for inverting output values of the first and second comparators, an operation unit for AND-gating the outputs of the amplifying units and outputs of the inverter, and a microcomputer for receiving an output of the operation unit, judging a degree of convergence correction, and outputting a corresponding control signal.

1. Field of the Invention
The present invention relates generally to a video display appliance, and more particularly, to an apparatus for preventing an auto-convergence error in a projection television receiver (TV) which prevents generation of an error when an auto-convergence is performed.
2. Description of the Related Art
Generally, diverse types of video display appliances including a small-sized analog television receiver (TV) to a large-sized projection TV of more than 60 inches have been provided to consumers.
A conventional apparatus for transmitting/receiving digital video data, as shown in FIG. 1, includes a transmitter part 100 which includes a video processor 102 and a digital-to-analog (DA) converter 104, and a receiver part 106 which includes an analog-to-digital (AD) converter 108 and a video processor 110.
A projection TV is an appliance which displays an image on a screen by projecting R, G, B colors on the screen using R, G, B Braun tubes, and its sensitivity items are W/U (White Uniformity), B/U (Bright Uniformity), convergence, focus, distortion, etc.
The convergence is to gather R (Red), G (Green), B (Blue) beams emitted from electron guns onto one spot on a screen by a magnetic field of a deflection yoke. If the electron beams are not properly deflected due to an abnormal operation of the deflection yoke or an influence of a magnetic field, a mis-convergence is generated, which deteriorates the color balance. That is, if the convergence is normally performed and the R, G, B beams accurately converge on a spot, an image of a white color is displayed. If a mis-convergence is generated, lines having colors of R, G, B may appear near by the image of the white color, and this deteriorates the picture quality.
Accordingly, in order to clearly display the image of the white color, the R, G, B beams should be gathered onto one spot, which is called an auto-convergence.
According to this auto-convergence, a specific pattern is produced on the screen, the degree of mis-convergence is detected using an optical sensor, and this mis-convergence is collected.
Hereinafter, a conventional convergence control apparatus for a projection TV will be explained with reference to the accompanying drawings.
FIG. 1 is a block diagram illustrating the construction of a conventional convergence control apparatus in a projection TV. FIG. 2 is a view showing a sensing method for an optical sensor according to the movement of a measurement pattern, and FIG. 3 is a waveform diagram illustrating an output waveform of an optical sensor according to the movement of the measurement pattern.
The conventional convergence control apparatus in a projection TV, as shown in FIG. 1, includes a screen 10 for displaying an image signal, first to eighth sensing units 11 to 18 mounted in a specified area of the screen 10, an amplifying unit 20 for receiving and amplifying sensed values outputted from the first to eighth sensing units 11 to 18 with a predetermined amplification factor, a comparing unit 30 for receiving amplified values outputted from the amplifying unit 20 through inverting (−) terminals and non-inverting (+) terminals and comparing the inputted amplified values, an inverter 40 for inverting the output value of the comparing unit 30, a D-type flip-flop 50 for latching an output value of the inverter 40, and a microcomputer 60 for receiving data through the D-type flip-flop 50 and outputting a control signal for a convergence control.
The first, third, fifth and seventh sensing units 11, 13, 15 and 17 among the first to eighth sensing units are positioned in the middle parts of borders of the screen 10, and the second, fourth, sixth and eighth sensing units are positioned at the corners of the screen 10, respectively. Also, the sensing units 11 to 18 are classified into a first group composed of the first to fourth sensing units 11 to 14 and a second group composed of the fifth to eighth sensing units 15 to 18, and each of the first to eighth sensing units 11 to 18 includes first and second optical sensors A and B as shown in FIG. 2.
The amplifying unit 20 includes a first amplifying unit 21 for receiving and amplifying the sensed values outputted through the first optical sensors A and the second optical sensors B of the first to fourth sensing units 11 to 14, and a second amplifying unit 22 for receiving and amplifying the sensed values outputted through the first optical sensors A and the second optical sensors B of the fifth to eighth sensing units 15 to 18.
Here, the first amplifying unit 21 includes a first amplifier 21a for receiving and amplifying values sensed through the first optical sensors A of the first to fourth sensing units 11 to 14, and a second amplifier 21b for receiving and amplifying values sensed through the second optical sensors B of the first to fourth sensing units 11 to 14. The second amplifying unit 22 includes a third amplifier 22a for receiving and amplifying values sensed through the first optical sensors A of the fifth to eighth sensing units 15 to 18, and a fourth amplifier 22b for receiving and amplifying values sensed through the second optical sensors B of the fifth to eighth sensing units 15 to 18.
The comparing unit 30 includes a first comparator 31 for receiving and comparing output values of the first and second amplifiers 21a and 21b, and a second comparator 32 for receiving and comparing output values of the third and fourth amplifiers 22a and 22b.
The operation of the conventional convergence control apparatus for a projection TV will now be explained.
If an auto-convergence control mode is selected, the position of a pattern is sensed through the first to eighth sensing units 11 to 18. The sensed values outputted through the first optical sensors A of the first to eighth sensing units 11 to 18 are inputted to the second and fourth amplifiers 21b and 22b, and the sensed values outputted through the second optical sensors B of the first to eighth sensing units 11 to 18 are inputted to the first and third amplifiers 21a and 22 the amplification factor of which is twice the amplification factor of the second and fourth amplifiers 21b and 22b.
The amplified value b1 outputted through the first amplifier 21a is inputted to the inverting (−) terminal of the first comparator 31, and the amplified value al outputted through the second amplifier 21b is inputted to the non-inverting (+) terminal of the first comparator 31, so that a compared value c1 is outputted from the first comparator 31. Also, the amplified value b2 outputted through the third amplifier 22a is inputted to the inverting (−) terminal of the second comparator 32, and the amplified value a2 outputted through the fourth amplifier 22b is inputted to the non-inverting (+) terminal of the second comparator 32, so that a compared value c2 is outputted from the second comparator 31.
The output values of the first and second comparators 31 and 32 are AND-gated, and then inputted to the inverter 40. The inverted value outputted through the inverter 40 is latched in the D-type flip-flop 50, and then inputted to the microcomputer 60.
Here, the sensing method according to the movement of the measurement pattern performed through the first to eighth sensing units 11 and 18 will be explained with reference to FIGS. 2 and 3.
If the pattern moves downwards in the case that the measurement pattern is red (or green or blue), the third sensing unit 13 performs the sensing process. As shown in FIG. 2, when the pattern is at a first sensing point t1, the pattern falls on neither of the first and second optical sensors A and B, and no light is sensed by both the first and second optical sensors A and B. In this case, low-level signals are applied to the first and second amplifiers 21a and 21b, and this causes low-level signals to be outputted from the first and second amplifiers 21a and 12b as shown in FIG. 3.
The low-level signals outputted from the first and second amplifiers 21a and 21b are inputted to the non-inverting (+) terminal and the inverting (−) terminal of the first comparator 31, and the first comparator 31 outputs a high-level signal. This is because several pull-up resistors are connected to the non-inverting (+) terminal of the first comparator 31.
Also, as shown in FIG. 2, if the pattern moves further and reaches a second sensing point t2, ½ of the pattern falls on the first optical sensor A, but no pattern falls on the second optical sensor B and no light is sensed by the second optical sensor B. In this case, the output value of the second amplifier 21b is larger than the output value of the first amplifier 21a, and thus the first comparator 31 continuously outputs a high-level signal.
If the pattern moves further and reaches a third sensing point t3, the pattern falls on the first optical sensor A in full, but ½ of the pattern falls on the second optical sensor B. In this case, the output value of the second amplifier 21b, which has received the sensed value of the first optical sensor A, becomes twice the output value of the first amplifier 21a, which has received the sensed value of the second optical sensor B (i.e., A=2B). However, since the amplification factor of the first amplifier 21a is twice the amplification factor of the second amplifier 21b, the output value of the first amplifier 21a is equal to the output value of the second amplifier 21b, and thus the first comparator 31 outputs a low-level signal thereafter.
In the same manner, the second comparator 32 outputs a low-level signal. The outputs of the first and second comparators 31 and 32 are AND-gated, and this AND-gated signal is inverted into a high-level signal through the inverter 40. This inverted high-level signal is inputted to the D-type flip-flop 50 as its clock so that the D-type flip-flop latches data, and then inputted to the microcomputer 60.
The microcomputer 60 judges the time point where its port goes from a low level to a high level as the third set position t3, judges the degree of the mis-convergence by measuring the distance from the initial position of the pattern to the third set position t3, and outputs a corresponding collection control signal.
The conventional auto-convergence error preventing apparatus in a projection TV, however, has the following problems:
First, if it is assumed that the pattern falls on the second set position t2 while the pattern is moved in order for any one of the optical sensing units mounted on the border of the screen to search for the third set position t3, the output of the comparator must be the high-level signal. However, if a surrounding light is inputted to other optical sensing units, the outputs of the corresponding comparators are varied, and this may cause the microcomputer to misrecognize the set position.
Second, if an external light is inputted to other sensing units besides the sensing unit subject to sensing, it affects the present sensing position, and it is difficult to measure the position accurately.
Third, as it is difficult to measure the position accurately, the convergence cannot be accurately controlled which deteriorates the picture quality.

Apparatus for preventing auto-convergence error in projection television receiver


Disclosed is a method of fabricating a semiconductor memory device including the step of irradiating ultraviolet rays on a metal interconnection at a bonding pad part, so that the metal interconnection can be prevented from being corroded because of a corrodent element in the process of erasing charges stored in a charge storage part. An oxide coating film is formed on the surface of the metal interconnection at the bonding pad part, and ultraviolet rays are irradiated onto the oxide coating film for erasing of charges from the floating gate.

1. Field of the Invention
The present invention relates to a method of fabricating a semiconductor memory device and a semiconductor memory device, and more particularly to a method of fabricating a non-volatile semiconductor memory device having the step of erasing charges cumulated in a charge storage part such as a floating gate by irradiating ultraviolet rays onto the surface of a metal wiring line of a bonding pad and such a semiconductor memory device.
2. Description of the Related Art
Semiconductor memories using MOSFETs (Metal Oxide Semiconductor Type Field Effect Transistor) are generally used for storing digital data. Among these semiconductor memories, an EEPROM (Electrically Erasable Programmable Read Only Memory) and a flash memory, which are electrically programmable ROMs, are used to store the program code of the cellular phone and a system BIOS (Basic Input Output System) of the mother board of the personal computer (PC).
The programmable ROMs as described above have the structure of storing information by accumulating charges in a charge storage part such as a floating gate.
It is known that hot electrons occur due to plasma used in the etching or ashing step of the process for fabricating the semiconductor memory devices with the floating gates and charges resulting from the hot electrons are injected in the floating gate. This may cause a memory malfunction. Further, if too many charges are stored, an insulating film that is in contact with the floating gate may be destroyed. In order to avoid these problems, the fabrication process is additionally provided with the step of erasing the charges stored in the floating gate by ultraviolet rays.
In the fabrication process for the general semiconductor memory devices including the programmable ROMs, it is known that a multilayer metallization is formed by the combination of deposition of a thin insulation or metal film, resist deposition, pattern transfer by photolithography, selective thin film removal by etching, and resist removal. Memory elements are formed by the combination of the multilayer metallization fabrication technique and MOS transistor fabrication technique. Further, the memory elements are packaged in order to prevent age deterioration of the memory elements function and implement the input/output function. In order to interconnect the input/output terminals of the package and the memory input/output signals on the semiconductor substrate, bonding pads electrically coupled with the memory elements formed on the substrate are formed.
However, the conventional fabrication method has the following problems. As has described, the final step on the substrate is to form the bonding pads. Thereafter, the charges stored in the floating gates are erased by irradiation of ultraviolet rays. In the step of forming the bonding pad parts, dry ashing such as plasma ashing using oxygen-based gas is employed to remove the resist. Then, wet ashing is performed using solution that contains hydroxylamine in order to completely remove the resist. During the above process, the metal oxide film formed on the metallization is removed, so that the metallization is exposed.
In this case, chlorine (Cl) and another ion are deposited on the metallization exposed during the etching process for the bonding pad parts, and react with moisture in the atmosphere. This causes corrosion of the aluminum metallization after etching. For example, corrosion occurs by the following reaction: Al+4CL−→AlCl4−+3e−,AlCl4−+3H2O→Al(OH)3+3H++4Cl−.
Even in the clean room, the density of Cl may exceed a reference situation in which the wafer may be contaminated so that ions of 300×E10 [molecule/cm2] have been deposited thereon after it remains for 24 hours in the uncontrolled state. Further, the solution for use in wet ashing may contain slight Cl. These factors may cause corrosion.
Furthermore, corroding may be enhanced by such a mechanism that Cl− ions and a reaction product deposited on the wafer by the resist removal apparatus and from another environment until the process of removing the charges stored in the floating gates by ultraviolet rays after the etching process for the bonding pad parts react with oxygen in the atmosphere with high optical energy of ultraviolet rays being used as activation energy when irradiating.

Method of fabricating semiconductor memory device and semiconductor memory device driver


Methods and systems are provided for controlling exhaust emissions by adjusting an injection profile for different fuels injected into an engine cylinder from different fuel injectors during engine start and crank. By splitting fuel injection during start and cranking so that fuel of lower alcohol content is port injected and fuel of higher alcohol content is direct injected as one or multiple injections, the soot load of the engine can be reduced and fuel economy can be improved.

Engines may be configured with direct fuel injectors that inject fuel directly into a combustion cylinder (direct injection), and/or with port fuel injectors that inject fuel into a cylinder port (port fuel injection). Multi-fuel engine systems can use both port and direct injection with different fuel types provided to the different injectors. For example, direct injection of ethanol fuel may be used with port injection of gasoline fuel. Therein, the direct injection of the alcohol fuel may take advantage of the increased charge cooling effects of the alcohol fuel's higher heat of vaporization and increased octane. This helps to address knock limitations, especially under boosted conditions. Further, the port injection of the gasoline fuel may take advantage of the higher power output of the gasoline fuel.
Direct injected engines, however, also generate more particulate matter emissions (or soot) due to diffuse flame propagation wherein fuel may not adequately mix with air prior to combustion. Since direct injection, by nature, is a relatively late fuel injection, there may be insufficient time for mixing of the injected fuel with air in the cylinder. Similarly, the injected fuel may encounter less turbulence when air is flowing past the valves. Consequently, there may be pockets of rich combustion that may generate soot locally, degrading exhaust emissions.
One approach for reducing particular matter emissions generated by direct injection of fuel is shown by Bidner et al. in US2011/0162620. Therein, an amount of fuel injected into the cylinder, between the direct injector and the port fuel injector, is adjusted based on the amount of particulate matter (PM) produced by the engine. For example, as a soot load increases, a fuel injection amount from the direct injector is decreased while a fuel injection amount from the port injector is correspondingly increased.
However, the inventors herein have identified potential issues with such an approach. In multi-fuel engine systems, where the fuel that is port injected is different (e.g., with a different alcohol content or a different fuel volatility) from the fuel that is direct injected, the shift towards more usage of the direct injected fuel may not sufficiently reduce PM emissions to meet the mandated low PM emission standards. For example, during selected engine operating conditions, the direct injection may be performed too late such that by the time the direct injection occurs, the emitted PMs are higher than emission standards. As another example, the higher soot load generated by the port injected fuel may eclipse the lower soot load generated by the direct injected fuel, obscuring the PM reduction resulting from the direct injection. The problem may be further exacerbated in multi-fuel engine systems due to the varying availability of the different fuels. For example, due to reduced availability of a first fuel (with a higher alcohol content or a higher fuel volatility) that is coupled to the direct injector, direct injection of the first fuel may be reduced and port injection of a second fuel (with a lower alcohol content or a lower fuel volatility) may be increased. As another example, increased port injection may be enabled for alternate reasons such as increased residence time of a fuel in the corresponding fuel tank. Further still, the fuel volatility may have interactions with the injector type. For example, port fuel injection can have problems with fuel volatility while direct injection is relatively insensitive to fuel volatility. As a result, fuels having higher volatility (e.g., fuels with higher T50 values) can greatly degrade cold port injected fuel combustion but have a much smaller effect on direct injected fuel combustion. As such, this can degrade combustion stability and increase potential for engine misfire. Overall, fuel economy and cold-start exhaust emissions may be degraded.
The above issues may be at least partly addressed by a method for an engine comprising: during a first combustion event since engine start, port injecting a first amount of a first fuel during a closed intake valve event; and direct injecting a second amount of a second fuel over multiple injections of the first combustion event, the first fuel having a lower alcohol content than the second fuel. In an alternate embodiment, the first fuel may have a lower fuel volatility than the second fuel. In this way, benefits from different fuel types as well as from a fuel injection split between port injection of a first fuel and (single or multiple) direct injection(s) of a second fuel can be synergized.
In one example, during an engine start, an engine control system may inject a first fuel having a lower alcohol content, or a lower fuel volatility (such as gasoline) for the first cylinder combustion event, as a first port injection delivered during a closed intake valve event (e.g., during an exhaust stroke of a previous cylinder). Further, a second fuel having a higher alcohol content, or a high fuel volatility (for example, a gasoline-ethanol blend such as E85) may be injected, on the first cylinder combustion event, as a second direct injection, the direct injected fuel delivered over multiple direct injections. For example, the direct injected second fuel may be delivered with at least one injection during an intake stroke, and at least one injection during a compression stroke. This may constitute a first injection profile. The first injection profile may be continued during cranking for a number of combustion events, based on the cylinder event number, until a threshold cylinder event number is reached. The number of combustion events over which the first injection profile is maintained may be based at least on the alcohol content or fuel volatility of the first and/or second fuel. For example, as the alcohol content of the second fuel increases, the number of combustion events may be increased (e.g., up to cylinder event number 24). Alternatively, as the fuel volatility of the second fuel increases, the number of combustion events may be increased. Further, the first ratio of port injected first fuel to direct injected second fuel may also be increased as the alcohol content of the second fuel relative to the alcohol content of the first fuel increases.
By injecting a first fuel with less alcohol content, or less volatility, as a port injection and a second fuel with more alcohol content, or more volatility, as a direct injection, an exhaust catalyst temperature can be rapidly increased to a light-off temperature, improving engine performance at engine cold-starts. By also splitting the direct injection so that some of the direct injected higher alcohol fuel is injected during the intake stroke and the remaining part of the fuel is injected during the compression stroke, the catalyst light-off temperature can be attained without raising exhaust particulate matter (PM) emissions and degrading engine combustion stability. At the same time fuel economy is improved. After a target cylinder combustion event number is reached, the injection profile may be transitioned to a second injection profile that is configured for engine idle speed control. The second injection profile may include, for example, only port injection of the first fuel, only direct injection of the second fuel (e.g., only in the intake stroke or only in the compression stroke), and/or a split ratio that is different from the split ratio of the first injection profile, with a higher percentage of second fuel direct injected. In still further embodiments, the injection profile during an engine cold start may vary based on the engine temperature at the cold start (e.g., based on whether it is a nominal temperature engine cold start or a very cold temperature engine cold start).
In this way, by using a split injection profile that splits fuel injection of different fuels between a port injection and multiple direct injections based on the properties of each available fuel, each fuel can be leveraged to reduce an activation time for an exhaust catalyst while also reducing gaseous and particulate matter emissions. At the same time, a higher amount of spark retard can be tolerated without affecting combustion stability. As such, this allows fuel injection to be optimized so as to enable the benefits of a fuel injection split between a port injection of a first fuel and direct injection of a second, different fuel to be synergized with the benefits of multiple direct injections, and be further synergized to take advantage of the different alcohol content of the different fuels. Overall, engine performance and exhaust emissions are improved, and further, fuel economy is also improved.
It should be understood that the summary above is provided to introduce in simplified form a selection of concepts that are further described in the detailed description. It is not meant to identify key or essential features of the claimed subject matter, the scope of which is defined uniquely by the claims that follow the detailed description. Furthermore, the claimed subject matter is not limited to implementations that solve any disadvantages noted above or in any part of this disclosure.


A short-wavelength light-emitting element such as an ultraviolet light-emitting element or blue light-emitting element is arranged in a container which has a window with a window board formed of calcium fluoride crystals. Fluoride crystals are ones which contain either metal or metal halide, or both of them. In a production method of fluoride crystals in which the cavity of a crucible is filled with raw material powder and this crucible is heated in a vertical Bridgman furnace, a production method of fluoride crystals of the present invention is the one in which the shortest diameter of a cross section of the cavity of the crucible is small. In a crucible, whose cavity is filled with raw material powder, heated in a vertical Bridgman furnace to produce fluoride crystals, a crucible is the one in which the shortest diameter of a section of the cavity is small.

In the past, in a light-emitting element device using a short-wavelength light-emitting element such as an ultraviolet light-emitting element or blue light-emitting element, this short-wavelength light-emitting element 1 such as an ultraviolet light-emitting element or blue light-emitting element has been covered, for example, with epoxy resin 2 as shown in FIG. 5.
Also, in a light-emitting element device which uses this short-wavelength light-emitting element 1 such as an ultraviolet light-emitting element or blue light-emitting element and is intended to obtain visible light through wavelength conversion, an element such as phosphorus has been mixed into this covering epoxy resin 2 so as to obtain yellow light.
Further, calcium fluoride crystals (fluorite) are generally known to be highly resistant to ultraviolet rays such as KrF and ArF excimer lasers (Published Japanese Patent Application No. 2001-33379).
However, this short-wavelength light-emitting element 1 such as an ultraviolet light-emitting element or blue light-emitting element is high in the energy of light, which thus decomposes couplings of the epoxy resin 2 or the like covering this short-wavelength light-emitting element 1 and causes devitrification. As a result, regarding a light-emitting element device using this short-wavelength light-emitting element 1, there has been such inconvenience in which light-emitting efficiency lowers noticeably or similar effects are caused, as it is used.
Further, when in order to perform wavelength conversion in a light-emitting element device using this short-wavelength light-emitting element 1 an element such as phosphorus, for example, is mixed into the covering epoxy resin 2 to obtain a light-emitting element device emitting yellow light, with the energy of this short-wavelength light, the decomposition of the epoxy resin 2 progresses as it is used, light-emitting efficiency deteriorates, and this phosphorus atom becomes directly attached to the surface of wiring of a diode constituting this short-wavelength light-emitting element 1, corroding this wiring and causing an inconvenience in which reliability is lowered greatly.
Meanwhile, the development of calcium fluoride which is great in hardness, excellent in acid resistance, small in dislocation density, and small in strain amount is being hoped for.

Short-wavelength light-emitting element arranged in a container with a window having a window board formed of a calcium fluoride crystals


A process for producing 2-hydroxy-4-methylthiobutanoic acid which includes conducting hydration and successive hydrolysis of 2-hydroxy-4-methylthiobutyronitrile in a reaction system containing 2-hydroxy-4-methylthiobutyronitrile and sulfuric acid, ammonium bisulfate being added to the reaction system at the time of the hydration and/or the hydrolysis, acquiring 2-hydroxy-4-methylthiobutanoic acid from the resulting organic layer, adding a water-miscible organic solvent to the by-produced aqueous layer to deposit ammonium sulfate, and separating and removing the ammonium sulfate from ammonium bisulfate, thereby permitting recycling and reusing of ammonium bisulfate, reduces the amount of sulfuric acid used, produces substantially no waste water containing sulfates and is of a low production cost and environmentally friendly.

Heretofore, 2-hydroxy-4-methylthiobutanoic acid has been produced by a process which comprises reacting 2-hydroxy-4-methylthiobutyronitrile with an equal molar or slight excess of sulfuric acid to hydrate and hydrolyze the nitrile compound, and separating the resulting reaction liquid into an aqueous layer and an oil layer containing 2-hydroxy-4-methylthiobutanoic acid. The aqueous layer, which contains ammonium bisulfate, is discarded without any after-treatment or discarded after neutralized with ammonia to form ammonium sulfate which is deposited and separated therefrom, see for example, U.S. Pat. No. 4,524,077 and U.S. Pat. No. 4,912,257. This process, however, is not an industrially recommendable process from the viewpoints of environmental friendliness as well as production cost, because it uses a large amount of sulfuric acid, forms a large amount of sulfates as by-products and moreover produces a large amount of sulfate-containing waste water.
A known process devised for reducing the amount of sulfuric acid used in the above-mentioned prior art process comprises thermally decomposing the by-produced sulfates to evolve SO.sub.3 and recovering the SO.sub.3 as sulfuric acid, see U.S. Pat. No. 5,498,790. However, this process requires complicated equipment for recovering sulfuric acid and requires a heavy investment for construction of the equipment.

Method for separating ammonium sulfate and ammonium bisulfate from each other and process for producing 2-hydroxy-4-methylthiobutanoic acid utilizing the method


An artificial ore, characterized in that it is prepared by melting one of silicon, a silicon compound, tourmaline and a ceramic, and adding iron, aluminum and calcium into the resultant melt to melt them, followed by cooling to a mass. The artificial core has good thermal properties such as heat conductivity, heat diffusion coefficient and fire resistance temperature, can dissociate molecules in a liquid, and further can prevent the electrification by static charge and the transmission of an electromagnetic wave.

Hitherto, a ceramic has been used extensively as a material having a good resistance to heat and a high degree of hardness. Such a ceramic is prepared by admixing raw materials such as alumina or the like and molding it, followed by sintering. The ceramic can be formed into various shapes upon molding so that it can be used for wide purposes.
Alumina as a representative ceramic has thermal properties including heat resistance of approximately 1,600° C., thermal conductivity of 36.0 (W/m/K), and a heat diffusion coefficient of 0.0119×103 (m2/s) (each value being measured at 300 K).
Although the conventional ceramic as described above has been used in a wide range of fields due to its heat resistance, anti-wearing property, readiness for processing and so on, the development of an artificial raw material having further improved thermal properties such as heat resistance has been desired.
Moreover, the conventional ceramic as described above has to be sintered after molding a mixture of the raw materials so that it requires a long time and a labor for the preparation thereof. Therefore, the development of an artificial ore easy for preparation has been desired.

Artificial ore and coating material or refractory block containing the artificial ore


A wire harness waterproof structure is provided that allows the water sealant to be visually checked, enables reliably filling of the periphery of a splice portion with the water sealant, and enables water in an unfilled region to easily drain. The wire harness waterproof structure includes electrical lines forming an intermediate splice portion, an exterior member surrounding the entire circumference of the intermediate splice portion and adjacent end portions, and a curing layer made up of a water sealant wherein a gap between the intermediate splice portion and the exterior member is filled. The waterproof sheet material is curved so as to surround the splice portion and the adjacent end portions. The sheet material has seeping holes allowing a portion of the curing layer to seep, and enable moisture to be drained to the outer surface in a region not filled with the water sealant.

In a wire harness installed in a vehicle such as an automobile, it is common to form a splice portion by partially stripping away the coverings of insulated sheathed electrical lines to partially expose the conductors (core lines) made up of conductor element wires, and then join the exposed conductor portions using a crimping terminal or ultrasonic welding. Also, in the case where waterproofing is required, such as the case where the splice portion is arranged in a water-exposed region in a vehicle, a waterproof structure that prevents corrosion of the splice portion is provided.
As a conventional waterproof structure of this type, there is known to be, for example, a waterproof structure in which tape with a thermal foaming adhesive material applied thereon is wrapped around a pair of sheathed end portions on the trunk line side from which the covering in an intermediate portion has been stripped and a sheathed end portion on the branch line side that is to be joined to the intermediate portion, and a waterproof sheet is cylindrically wrapped around and adhered to the sheathed end portions and the splice portion from the outside (e.g., see JP H7-245842A).
Also, there is known to be a technique in which the exposed conductor portions in intermediate portions of a pair of insulated sheathed electrical lines are joined together, a water sealant is applied around them, then the splice portion is covered with a flexible and light-permeable protective sheet, and the water sealant is brought into close contact with the periphery of the splice portion by applying appropriate tensile force to the protective sheet, for example, while causing the protective sheet to following the contraction during the light curing of the water sealant (e.g., see JP 2012-80633A).
JP H7-245842A and JP 2012-80633A are examples of related art.
However, in the former conventional wire harness waterproof structure that uses tape with a thermal foaming adhesive material applied thereon as described above, there is an unresolved issue in that if the amount of thermal foaming adhesive material is too high, it is likely to leak out from the two end portions of the cylindrical waterproofing sheet, but if the amount of thermal foaming adhesive material is too low, it is not possible for the thermal foaming adhesive material to reach the splice portion side.
Also, in the latter conventional wire harness waterproof structure in which a flexible protective sheet is used and caused to follow the deformation during curing of the water sealant, there is an unresolved issue in that even if the protective sheet is light-permeable, it is not possible to easily visually check from outside the protective sheet whether or not the water sealant has reliably penetrated into the spaces between the element wires, for example, or whether or not the water sealant has penetrated into the spaces between the end portions of the covering and the core line made up of a group of conductor element wires.
For this reason, conventionally, unless the waterproofing section in the vicinity of the splice portion is lengthened and the water sealant filling amount is set high, there is a possibility of water entering the splice portion in the case where the splice portion is arranged in a water-exposed area in the vehicle, for example. Also, it has not been possible to avoid the issue that once water has entered the splice portion covered by the waterproofing sheet, it is difficult for the water to be drained.
The present invention was achieved in order to solve conventional issues such as those described above, and an object thereof is to provide a wire harness waterproof structure that enables the water sealant filling state in the periphery of the splice portion to be easily visually checked from outside the protective sheet or the like, that enables reliably filling the periphery of the splice portion with the water sealant without using a large amount of water sealant, and also enables water that has entered an unfilled region to be easily drained.


A neural network module including an input layer having one or more input nodes arranged to receive input data, a rule base layer having one or more rule nodes, an output layer having one or more output nodes, and an adaptive component arranged to aggregate selected two or more rule nodes in the rule base layer based on the input data, an adaptive learning system having one or more of the neural network modules, related methods of implementing the neural network module and an adaptive learning system, and a neural network program.

Real world problems, such as massive biological data analysis and knowledge discovery, adaptive speech recognition and life-long language acquisition, adaptive intelligent prediction and control systems, intelligent agent-based systems and adaptive agents on the Web, mobile robots, visual monitoring systems, multi-modal information processing, intelligent adaptive decision support systems, adaptive domestic appliances and intelligent buildings, systems that learn and control brain and body states from a biofeedback, systems which classify bio-informatic data, and other systems require sophisticated solutions for building on-line adaptive knowledge base systems.
Such systems should be able to learn quickly from a large amount of data, adapt incrementally in an on-line mode, have an open structure so as to allow dynamic creation of new modules, memorise information that can be used later, interact continuously with the environment in a "life-long" learning mode, deal with knowledge as well as with data, and adequately represent space and time in their structure.
Well established neural network and artificial intelligence (AI) techniques have difficulties when applied for on-line knowledge based learning. For example, multi-layer perceptrons (MLP) and backpropagation learning algorithms have a number of problems, for example catastrophic forgetting, local minima problem, difficulties in extracting rules, inability to adapt to new data without retraining on old data, and excessive training times when applied to large data sets.
The self-organising map (SOM) may not be efficient when applied for unsupervised adaptive learning on new data, as the SOM assumes a fixed structure and a fixed grid of nodes connected in a topological output space that may not be appropriate to project a particular data set. Radial basis neural networks require clustering to be performed first and then the back propagation algorithm applied. Neuro-fuzzy systems cannot update the learned rules through continuous training on additional data without catastrophic forgetting.
These type of networks are not efficient for adaptive, on-line learning, although they do provide an improvement over prior techniques.