The present invention relates to a membrane electrode unit comprising a polymer membrane doped with a mineral acid as well as two electrodes, characterized in that the polymer membrane comprises at least one polymer with at least one nitrogen atom and at least one electrode comprises a catalyst which is formed from at least one precious metal and at least one metal less precious according to the electrochemical series.

The present invention relates to high-performance membrane electrode units, which can particularly be used in so-called polymer electrolyte membrane fuel cells.
A fuel cell usually contains an electrolyte and two electrodes separated by the electrolyte, in which one of the two electrodes is supplied with a fuel, such as hydrogen gas or a mixture of methanol and water, and the other electrode is supplied with an oxidant, such as oxygen gas or air. In the process, chemical energy generated by the resulting fuel oxidation is directly converted into electric power.
One requirement of the electrolyte is that it is permeable to hydrogen ions, i.e. protons, but not to the fuels mentioned above.
Typically, a fuel cell comprises several individual cells, so-called MEUs (membrane electrode unit), each of which contains an electrolyte and two electrodes separated by the electrolyte.
As electrolyte for the fuel cell, solids, such as polymer electrolyte membranes, or liquids, such as phosphoric acid, are applied. Polymer electrolyte membranes have recently attracted interest as electrolytes for fuel cells.
Polymer electrolyte membranes with complexes of alkaline polymers and strong acids are known from WO96/13872, for example. To produce these, an alkaline polymer, for example polybenzimidazole, is treated with a strong acid, such as phosphoric acid.
Furthermore, fuel cells whose membrane comprises inorganic support materials, such as for example glass-fibre fabrics or glass-fibre veils, which are saturated with phosphoric acid, are also known, for example from U.S. Pat. No. 4,017,664.
In the alkaline polymer membranes known in the prior art, the mineral acid (mostly concentrated phosphoric acid) used—to achieve the required proton conductivity—is usually added following the forming of the polyazole film. In doing so, the polymer serves as a support for the electrolyte consisting of the highly concentrated phosphoric acid. In the process, the polymer membrane fulfils further essential functions, particularly, it has to exhibit a high mechanical stability and serve as a separator for the two fuels mentioned at the outset.
An essential advantage of such a membrane doped with phosphoric acid is the fact that a fuel cell in which such a polymer electrolyte membrane is employed can be operated at temperatures above 100° C. without the humidification of the fuels otherwise necessary. This is due to the characteristic of the phosphoric acid to be able to transport the protons without additional water via the so-called Grotthus mechanism (K.-D. Kreuer, Chem. Mater. 1996, 8, 610-641).
Further advantages for the fuel cell system are achieved through the possibility of operation at temperatures above 100° C. On the one hand, the sensitivity of the Pt catalyst to gas impurities, in particular CO, is reduced substantially. CO is formed as a by-product in the reforming of hydrogen-rich gas from carbon-containing compounds, such as e.g. natural gas, methanol or benzine, or also as an intermediate product in the direct oxidation of methanol. Typically, the CO content of the fuel has to be lower than 100 ppm at temperatures <100° C. However, at temperatures in the range of from 150-200°, 10,000 ppm CO or more can also be tolerated (N. J. Bjerrum et. al., Journal of Applied Electrochemistry, 2001, 31, 773-779). This results in substantial simplifications of the upstream reforming process and therefore reductions of the cost of the entire fuel cell system.
The output of a membrane electrode unit produced with such membranes is described in WO 01/18894 and in Electrochimica Acta, Volume 41, 1996, 193-197 and amounts to less than 0.2 A/cm2 with a platinum loading of 0.5 mg/cm2 (anode) and 2 mg/cm2 (cathode) and a voltage of 0.6 V. When using air instead of oxygen, this value drops to less than 0.1 A/cm2.
A big advantage of fuel cells is the fact that, in the electrochemical reaction, the energy of the fuel is directly converted into electric power and heat. In the process, water is formed at the cathode as a reaction product. Heat is also produced in the electrochemical reaction as a by-product. In applications in which only the power for the operation of electric motors is utilised, such as e.g. in automotive applications, or as a versatile replacement of battery systems, part of the heat generated in the reaction has to be dissipated to prevent overheating of the system. Additional energy-consuming devices which further reduce the total electric efficiency of the fuel cell are then needed for cooling. In stationary applications, such as for the centralised or decentralised generation of electricity and heat, the heat can be used efficiently by existing technologies, such as e.g. heat exchangers. In doing so, high temperatures are aimed for to increase the efficiency. If the operating temperature is higher than 100° C. and the temperature difference between the ambient temperature and the operating temperature is high, it will be possible to cool the fuel cell system more efficiently, for example using smaller cooling surfaces and dispensing with additional devices, in comparison to fuel cells which have to be operated at less than 100° C. due to the humidification of the membrane.

High-performance membrane electrode unit and the use thereof in fuel cells


A wear testing device includes a plurality of holding portions that hold rubber samples. The rubber samples held by each of the plurality of holding portions are independently and simultaneously pressed against a circumferential surface of a rotation body in rotation by a pressing mechanism so that abrasion debris of each of the rubber samples produced via this contact falls downward.

In the related art, a DIN (German Institute for Standardization) abrasion tester and a Williams abrasion tester are known testers for evaluating the wear resistance of rubber. These testers perform a test basically on one rubber sample at a time. Thus, to obtain test results from a plurality of rubber samples, sufficient time is needed or a plurality of testers are needed.
An example of a device that simultaneously tests a plurality of rubber samples is a testing device in which a plurality of rubber samples (test pieces) are attached to a first shaft and a plurality of counterpart pieces are attached to a second shaft (see Japan Utility Model Patent No. 3003469). This testing device has a structure whereby the opposing rubber samples and the counterpart pieces are pressed together at a predetermined pressing force by a pressing device and are rotationally driven while running against one another to wear the rubber samples.
However, this testing device has a structure whereby the rubber samples are pressed against the counterpart pieces as a group and not individually. Thus, when rubber samples having a different amount of wear per unit time are simultaneously tested, the pressing force against the relatively easily worn rubber sample is reduced. This prevents an accurate determination of the relative wear resistance of the rubber samples, and thus there is room for enhancement.


When a difference between a diaphragm target position and a detected state of a diaphragm is less than a neutral zone width, a driving control operation of the diaphragm is prohibited. The neutral zone width can be changed depending on the state of the diaphragm.

1. Field of the Invention
The present invention relates to an imaging device, such as a lens apparatus and a camera, which has a diaphragm control mechanism. More specifically, the present invention relates to a control apparatus and a control method capable of accurately controlling a diaphragm and capable of stabilizing a diaphragm action free from a hunting phenomenon.
2. Description of the Related Art
An imaging apparatus, such as a video camera, can include a position servo control mechanism capable of controlling a mechanical diaphragm provided therein. According to a conventional position servo control system, a Hall element can be used as a position sensor detecting the position of diaphragm blades (sectors).
The control system can obtain a difference between an output of the position sensor (the Hall element) and a target position of the diaphragm, and can produce a voltage signal representing the obtained difference. Furthermore, the control system can apply gain adjustment and phase compensation processing to the signal. The voltage signal is supplied to a diaphragm driving coil. The current corresponding to the applied voltage flows in the diaphragm driving coil. As a result, positional changes occur in the blades of the diaphragm and can be recognized as an output change in the position sensor. By repeating the above-described action, the control system can accomplish the diaphragm control.
However, when the position signal includes noises or any change occurs in frequency characteristics (for example, due to change of temperature), the diaphragm may not accurately stop at the target position and the diaphragm may cause a hunting phenomenon in the vicinity of the target position. That is, the diaphragm repeats opening and closing movements. If the servo action period is long, the hunting phenomenon appears as a change in the light quantity. If the servo action period is short, the diaphragm generates action sounds.
To solve this problem, it is possible to provide a neutral zone. According to a conventional technique, when a deviation between a detected diaphragm position and a target diaphragm position is less than a predetermined value, the deviation is regarded as 0 and no driving action is taken. For example, a neutral zone applicable to the exposure control of a camera is discussed in Japanese Patent Application Laid-open No. 10-276363.
Providing a neutral zone is generally effective to eliminate or suppress a hunting phenomenon. The stability of the diaphragm control can be improved. However, if an excessively large neutral zone is set, the deviation increases largely. On the other hand, if the deviation is decreased, the stability deteriorates.
FIG. 2A shows a relationship between an f-number indicating the state of the diaphragm and an output of the Hall element representing the diaphragm position. When the f-number increases discretely (i.e., by the steps of 1.4, 2.0, 2.8, 4.0 . . . ), the light quantity decreases in decrements of ½. However, the output of the Hall element (i.e., the diaphragm position) does not decrease in decrements of ½ and increases and decreases nonlinearly.
When the diaphragm value varies in the vicinity of a fully closed position of the diaphragm blades (refer to F22), a corresponding output change in the Hall element is small. On the other hand, when the diaphragm value varies in the vicinity of a fully opened position of the diaphragm blades (refer to the F1.4), a corresponding output change in the Hall element is large.
Accordingly, if a shifting motion of the diaphragm blades is controlled so as to produce a constant output change in the Hall element, the light quantity change is large in the f-number region corresponding to F22 and small in the f-number region corresponding to F1.4. As a result, as shown in FIG. 2B, the sensitivity in the light quantity change responsive to the position change of the diaphragm blades is high in the f-number region corresponding to F1.4 and low in the f-number region corresponding to F22.
Accordingly, when a neutral zone has a width corresponding to an output change of the Hall element responsive to the position change of the diaphragm blades in the f-number region corresponding to F1.4 (i.e., the region having a lower sensitivity in the light quantity change), the determined neutral zone is excessively wide for the f-number region corresponding to F22. Accordingly, the diaphragm stops with a large deviation in the light quantity when the f-number is equal to F22 or in its vicinity.
Therefore, in light of the aforementioned, it would be desirable to provide an apparatus and technique capable of setting an appropriate neutral zone for a diaphragm control apparatus and an optical apparatus including the diaphragm control apparatus.

Apparatus and method for controlling diaphragm of imaging apparatus


A vitrified bond tool including: (a) a support body; (b) a vitrified bond layer which is formed on a working surface of the support body; and (c) a plurality of abrasive grains which are held by the vitrified bond layer so as to be fixed relative to the working surface of the support body and which are spaced apart from each other with spacing between the adjacent ones of the abrasive grains. This vitrified bond tool is advantageously manufactured according to a method including the steps of (i) forming a pattern layer which includes a vitrified bond, in a predetermined pattern on the working surface of the support body; (ii) sprinkling the abrasive grains over the pattern layer before the pattern layer is dried; and (iii) firing the pattern layer and the abrasive grains which are bonded to the pattern layer and are arranged in the predetermined pattern on the working surface of the support body.

1. Field of the Invention
The present invention relates in general to a vitrified bond tool, and more particularly to such a vitrified bond tool including super abrasive grains and used as a dressing tool for dressing a polishing tool such as a polishing pad which is used for a chemical mechanical polishing of a semiconductor wafer.
2. Discussion of the Related Art
In a process of manufacturing a semiconductor, there is commonly practiced a chemical mechanical polishing (herein after referred to as xe2x80x9cCMPxe2x80x9d) operation. In recent years, since a larger number of sheets of wafers are laminated with a larger scale of integration of electronic circuit, CMP operation is widely practiced for flattening surfaces of the wafers. In CMP operation, a polishing pad and a semiconductor wafer are rotated relative to each other, with application of a polishing fluid including fine abrasive grains to the polishing pad, for polishing the semiconductor wafer. In CMP operation for a semiconductor wafer, a high degree of flatness in the polished surface of the wafer is required by polishing a considerably small amount of the surface of the wafer. For satisfying this requirement, the polishing pad has to be dressed very frequently. The polishing pad has been conventionally dressed by using an electro-deposited diamond tool, which includes a base metal made of stainless or other metallic material, and diamond abrasive grains bonded to the base metal with Ni metal (electro-deposition bond).
JP-A-10-71559 discloses a dresser for dressing a polishing pad used for polishing a semiconductor wafer. This dresser includes a base metal and a diamond thin film. The to base metal has, in its working surface, a multiplicity of protrusions formed by using a wire-EDM (electro-discharge machining) or a metallic mold. The diamond thin film is formed on the working surface of the base metal by a vapor phase synthetic method.
JP-A-10-193266 discloses a method of a vitrified bond tool, which was proposed by the present inventors. This method is characterized by including the step of positioning a screen having a predetermined printing pattern, on a support body; the step of applying a paste including abrasive grains and vitrified bond which are dispersed in the paste, onto the support body through the screen; and the step of sintering the applied paste.
However, the operation for dressing the polishing pad with the electro-deposited diamond tool, in which the diamond abrasive grains are bonded to the base metal by Ni metal as an electro-deposition bond, suffers from elution of Ni metal into the polishing fluid whereby the workpiece is contaminated by Ni metal, particularly, where the polishing fluid is a strong-acid fluid. Further, the electro-deposited diamond tool has a drawback that all of the abrasive grains are not bonded to the base metal with sufficiently large bonding strength, due to the random arrangement of the abrasive grains in the abrasive layer, so that some of the abrasive grains which are not firmly bonded to the base metal are removed from the base metal and accordingly stay on the polishing pad. The workpiece is scratched or damaged by the abrasive grains thus staying on the polishing pad.
The dresser disclosed in JP-A-10-71559, in which abrasive grains are not used, requires a process of forming the multiplicity of protrusions in its base metal and also a process of forming the diamond thin film by the vapor phase synthetic method, thereby resulting in a considerably increased manufacturing cost. Dressers disclosed in JP-A-10-44023 and JP-A-10-138120 are costly to manufacture, too.
In the method disclosed in JP-A-10-193266, in which the paste including the abrasive grains and the vitrified bond therein is applied onto the support body through the screen, the abrasive grains are unlikely to be sufficiently dispersed in the paste, due to possible sedimentation of the abrasive grains, where each of the abrasive grains has a diameter larger than 40 xcexcm. Thus, the paste applied onto the support body could be fixed to the support body in the sintering step, with agglomeration of the abrasive grains.
It is therefore a first object of the present invention to provide a vitrified bond tool having a construction which minimizes removal of the abrasive grains from the support body and accordingly prevents contamination or damage of a polishing tool and a workpiece to be polished by the polishing tool, and which is inexpensive to manufacture.
A second object of the invention is to provide a method suitable for manufacturing such a vitrified bond tool.
The first object indicated above may be achieved according to a first aspect of this invention, which provides a vitrified bond tool comprising: (a) a support body; (b) a vitrified bond layer which is formed on a working surface of the support body; and (c) a plurality of abrasive grains which are held by the vitrified bond layer so as to be fixed relative to the working surface of the support body and which are spaced apart from each other with spacing between adjacent ones of the abrasive grains.
In the vitrified bond tool according to the first aspect of the invention, the abrasive grains bonded to the vitrified bond tool are positioned relative to each other so as to be spaced apart from each other, so that each of the abrasive grains is bonded at an increased area of a surface thereof to the vitrified bond layer. Thus, all of the abrasive grains are bonded to the vitrified bond layer with sufficiently large bonding strength, thereby preventing removal of the abrasive grains from the vitrified bond layer or the support body, when this vitrified bond tool is used as a polishing or grinding tool for polishing or grinding a workpiece, or as a dressing tool for dressing a polishing or grinding tool. The workpiece polished or ground by this vitrified bond tool, or the polishing or grinding tool dressed by this vitrified bond tool and a workpiece polished or ground by the polishing or grinding tool is advantageously prevented from being contaminated and damaged by removal of the abrasive grains. The vitrified bond tool maintains its cutting sharpness throughout successive polishing or grinding operations, and accordingly exhibits an excellent polishing or grinding performance with high stability. In view of these advantages, the vitrified bond tool of this invention is suitable for dressing a polishing pad which is required to assure a high degree of flatness in a surface of a semiconductor wafer by polishing a considerably small amount of the surface of the wafer.
The vitrified bond tool provides other advantages. For example, the support body constituting a part of the vitrified bond tool may consist of a conventional support body. That is, a conventional support body can be used as the support body of the present vitrified bond tool, without necessity of a particular machining to the conventional support body.
In the present vitrified bond tool, agglomeration of the abrasive grains is prevented, so that each of the abrasive grains sufficiently exhibits its own polishing or grinding capacity. This makes it possible to reduce the amount or number of the abrasive grains to be used for each vitrified bond tool of the invention, thereby leading to a reduced manufacturing cost.
In the present vitrified bond tool in which each of the abrasive grains is bonded at an increased area of its surface to the vitrified bond layer, all of the abrasive grains are bonded to the vitrified bond layer with sufficiently large bonding strength, even with a reduced thickness of the vitrified bond layer. The reduced thickness of the vitrified bond layer facilitates protrusions of the abrasive grains from the vitrified bond layer after a firing step, i.e., after the manufacture of the tool, so that the vitrified bond tool does not have to be subjected to a truing operation, prior to an initial use thereof. That is, the vitrified bond tool exhibits an expected polishing or grinding performance even in the initial use without the truing operation.
The support body of the vitrified bond tool of the invention may be made of a ceramic or glassy material such as a silicon nitride or an alumina, without including any metallic material. Also in this view, the vitrified bond tool of the invention is suitable for dressing the polishing pad used to perform CMP operation for a semiconductor wafer which should be free from a metallic contamination.
It is desirable that thermal expansion coefficients of the abrasive grains, the vitrified bond layer and the support body are substantially equal to each other. That is, the difference between the abrasive grains and the vitrified bond layer in thermal expansion coefficients and the difference between the support body and the vitrified bond layer in thermal expansion coefficients are preferably not larger than 5xc3x9710xe2x88x926, more preferably not larger than 4xc3x9710xe2x88x926, and still more preferably not larger than 3xc3x9710xe2x88x926, for preventing cracking of the tool in the firing step.
According to a first preferred form of the first aspect of the invention, the abrasive grains protrude from a surface of the vitrified bond layer such that a distance over which each one of the abrasive grains protrudes from the surface of the vitrified bond layer corresponds to 20-70% of a diameter of the abrasive grain. This construction permits the abrasive grains to be held by the vitrified bond layer with a sufficiently high bonding strength, thereby preventing removal of the abrasive grains from the vitrified bond layer or the support body. If the protruding distance of each abrasive grain is larger than 70% of the diameter of the abrasive grain, the abrasive grain cannot be held by the vitrified bond layer with a sufficiently high bonding strength. If the protruding distance of each abrasive grain is smaller than 20% of the diameter of the abrasive grain, the dressing capacity of the vitrified bond tool is reduced.
According to a second preferred form of the first aspect of the invention, the abrasive grains are positioned relative to each other so as to be dotted on the working surface of the support body.
According to a third preferred form of the first aspect of the invention, the abrasive grains are positioned relative to each other such that the spacing between the adjacent ones of the abrasive grains is held in a predetermined range.
According to a fourth preferred form of the first aspect of the invention, the abrasive grains are positioned relative to each other by a precursor of the vitrified bond layer. It is noted that the precursor of the vitrified bond layer may be interpreted to correspond to a pattern layer which is described below.
The vitrified bond tools of the second, third and fourth preferred forms of the invention provide the same advantages as those of the vitrified bond tool of the first aspect of the invention as described above, and some additional advantages which will be clarified by description of preferred embodiments and examples as described below.
According to a fifth preferred form of the first aspect of the invention, the vitrified bond tool is designed as a dressing tool to be brought in sliding contact with a polishing surface of a polishing pad, for eliminating clogging in the polishing surface. The vitrified bond tool of this fifth preferred form further comprises, in addition to the plurality of abrasive grains as a plurality of first abrasive grains, a plurality of second abrasive grains whose average diameter is smaller than an average diameter of the first abrasive grains; wherein the working surface of the support body is a dressing surface which is forced onto the polishing surface of the polishing pad and which constitutes a part of a surface layer of the support body, at least the surface layer of the support body being made of an inorganic material; and wherein the second abrasive grains are held by the vitrified bond layer and are disposed on the dressing surface of the support body, such that the second abrasive grains are mingled together with each other, and such that the second abrasive grains are positioned between the first abrasive grains and are spaced apart from the first abrasive grains.
According to this fifth preferred form, in the dressing surface of the support body in which at least the surface layer is made of an inorganic material, the first abrasive grains which are spaced apart from each other are held by the vitrified bond layer, i.e., an inorganic bond layer, while the second abrasive grains whose average diameter is smaller than the average diameter of the first abrasive grains are also held by the vitrified bond layer such that the second abrasive grains are mingled together with each other. This construction prevents elution or effluence of a metallic component, even if a strong-acid fluid is used as the polishing fluid, thereby eliminating a risk of contamination of the workpiece. Further, the presence of the second abrasive grains between the adjacent ones of the first abrasive grains prevent the vitrified bond layer from being brought in contact with the polishing pad, thereby avoiding breakage of the vitrified bond layer.
The support body of the vitrified bond tool of this fifth preferred form may be made of a suitable ceramic material which has a high degree of chemical stability and sufficiently high degrees of strength and toughness for serving as a dressing tool. Such a ceramic material may be a sintered body of an inorganic material selected from alumina Al2O3, silicon nitride Si3N4, silicon carbide SiC, zirconia and mullite, or a glass having a high melting point. The vitrified bond layer of the vitrified bond tool of the fifth preferred form may be made of borosilicate glass, crystallized glass, silica glass, alumina, silicon nitride, silicon carbide, mullite, zirconia or other ceramic powders having sufficiently high degree of strength and toughness and a fusing point lower than that of the support body. Such suitable selections of materials for the support body and the vitrified bond layer are effective to avoid effluence of a metallic component into the polishing fluid thereby preventing the workpiece from being contaminated by an effluent metallic component, and also to avoid removal of the abrasive grains from the support body or the vitrified bond layer thereby preventing the workpiece from being scratched.
According to one advantageous arrangement of the fifth preferred form, the vitrified bond layer consists of a borosilicate glass including at least SiO2 and B2O3 such that the content of SiO2 therein is 40-70 wt % and the content of B2O3 therein is 10-30 wt %. The chemical composition of the borosilicate glass may include, for example, 40-70 wt % of SiO2, 0-20 wt % of Al2O3, 10-30 wt % of B2O3, 0-10 wt % of at least one kind of metal oxide RO which is selected from alkaline earth metals, and 0-10 wt % of at least one kind of metallic oxide R2O which is selected from alkaline metals. This arrangement makes it possible to burn or fire the vitrified bond layer at a low temperature, thereby facilitating the manufacturing of the vitrified bond tool.
According to another advantageous arrangement of the fifth preferred form, the first abrasive grains have a higher degree of hardness than the second abrasive grains. The first and second abrasive grains may be made of diamond, CBN, alumina, silicon carbide, silicon nitride, mullite, silicon dioxide (SiO2) or other material. For example, the first abrasive grains may be diamond abrasive grains having grain size of #100/#120, while the second abrasive grains may be alumina abrasive grains having grain size of #150/#180. According to this arrangement, the first abrasive grains which serve to dress the polishing pad have a comparatively high degree of hardness, while the second abrasive grains which serve to prevent contact of the vitrified bond layer with the polishing pad have a comparatively low degree of hardness and are made of a material comparatively cheap, thereby reducing the manufacturing cost of the vitrified bond tool.
According to still another advantageous arrangement of the fifth preferred form, the ratio of the number of the second abrasive grains to the number of the first abrasive grains is 1-10, or more preferably 2-5. This arrangement is effective to increase a load applied to each one of the first abrasive grains, thereby providing an excellent dressing performance. If the above-described ratio is lower than 1 or 2, namely, if the number of the first abrasive grains relative to the number of the second abrasive grains is too increased, the load applied to each first abrasive grain is made too small, resulting in a reduced dressing performance. On the other hand, if the above-described ratio is higher than 5 or 10, namely, if the number of the first abrasive grains relative to the number of the second abrasive grains is too reduced, the load applied to each first abrasive grain is made too large, undesirably increasing possibility of removal of the abrasive grains.
The above-indicated second object may be achieved according to a second aspect of this invention, which provides a method of manufacturing the vitrified bond tool as defined in the above-described first aspect of this invention. The present method comprises the steps of: (i) forming a pattern layer which includes a vitrified bond, in a predetermined pattern on the working surface of the support body; (ii) sprinkling the abrasive grains over the pattern layer before the pattern layer is dried; and (iii) firing the pattern layer and the abrasive grains which adhere to the pattern layer and are arranged in the predetermined pattern on the working surface of the support body.
The vitrified bond tool of the present invention can be manufactured according to this method of the second aspect of the invention with high efficiency and at a reduced cost. The present method provides the vitrified bond tool in which the abrasive grains are arranged in a direction parallel to the working surface of the support body so that the abrasive grains constitute a single layer, and in which a lower portion of each abrasive grain is embedded in the vitrified bond layer while an upper portion of each abrasive grain is not covered by the vitrified bond layer and protrudes from the vitrified bond layer. Further, the present method makes it possible to arrange the abrasive grains on the support body in various patterns. By suitably arranging the abrasive grains on the support body depending upon its purpose, it is possible to manufacture the vitrified bond tool having the abrasive-grains-holding capacity and the polishing capacity suitable for the purpose.
The present inventors proposed, in JP-A-10-193266, the vitrified bond tool characterized by including the support body, and the abrasive grains cooperating with each other to form an abrasive layer which is bonded by the vitrified bond to the support body. The present inventors have now accomplished the present invention, as a result of a further study, which provides the vitrified bond tool wherein the positions of the abrasive grains relative to the working surface of the support body are more exactly controllable two-dimensionally or three-dimensionally.
According to a first preferred form of the second aspect of the invention, the method further comprises the steps of: (iv) forming a backing layer which includes a vitrified bond, on the working surface of the support body; and (v) forming a pattern layer which includes a vitrified bond, in a predetermined pattern on the backing layer.
According to a second preferred form of the second aspect of the invention, the method further comprises the step of (vi) applying one of a paste and a slurry including a vitrified bond, on the working surface of the support body, for thereby forming a coating layer which surrounds each of the abrasive grains on the working surface of the support body.
The vitrified bond tool defined above in the fifth preferred form of the first aspect of the invention can be manufactured according to a method comprising the steps of: (vii) mixing the first and second abrasive grains with each other with a predetermined ratio of the number of the second abrasive grains to the number of the first abrasive grains; (viii) printing an abrasive-grains-adhering paste on the dressing surface, such that the pattern layer is formed of the abrasive-grains-adhering paste, on the dressing surface, in a dotted pattern consisting of a plurality of dots each having a diameter which is smaller than an average diameter of the first abrasive grains and which is larger than 30% of the average diameter of the first abrasive grains; (ix) sprinkling the first and second abrasive grains over the pattern layer formed on the dressing surface, so that ones of the first and second abrasive grains adhere to the pattern layer; (x) removing the others of the first and second abrasive grains which are not bonded to the pattern layer; and (xi) firing the pattern layer and the above-described ones of the first and second abrasive grains, so that the above-described ones of the first and second abrasive grains are held by the vitrified bond layer, so as to be fixed relative to the dressing surface of the support body.
According to the present method, the mixture of the first and second abrasive grains are sprinkled over the pattern layer which is formed on the dressing surface, in the dotted pattern consisting of the plurality of dots each having the diameter which is smaller than the average diameter of the first abrasive grains and which is larger than 30% of the average diameter of the first abrasive grains, so that ones of the first and second abrasive grains adhere to the pattern layer. The others of the first and second abrasive grains which do not adhere to the pattern layer are removed, and then the pattern layer and the adhering ones of the first and second abrasive grains are fired in the firing step, so that the adhering ones of the first and second abrasive grains are held by the vitrified bond layer, so as to be fixed relative to the dressing surface of the support body.
In the vitrified bond tool manufactured according to the present method, the first abrasive grains are held by the vitrified bond layer so as to be fixed relative to the dressing surface and are spaced apart from each other, while the second abrasive grains are held by the vitrified bond layer so as to be fixed relative to the dressing surface and are mingled together with each other such that the second abrasive grains are positioned between the first abrasive grains and are spaced apart from the first abrasive grains. Since at least the surface layer which is partially constituted by the dressing surface is made of the inorganic material, there is no risk of effluence of a metallic component even if a strong-acid fluid is used as the polishing fluid. Since the second abrasive grains whose average diameter is smaller than the average diameter of the first abrasive grains are positioned to be spaced apart from each other or to be spaced apart from the first abrasive grains, each of the second abrasive grains is bonded at an increased area of a surface thereof to the vitrified bond layer with a sufficiently large bonding strength. Further, the presence of the second abrasive grains between the first abrasive grains on the vitrified bond layer prevent the vitrified bond layer from being brought in contact with the polishing pad, thereby avoiding breakage of the vitrified bond layer.
The abrasive-grains-adhering paste may be, preferably, a slurry liquid having a high degree of viscosity, and includes an inorganic-bonding-agent powder which is dispersed in an organic solvent, water or other solvent, and further includes, as needed, a dispersing agent serving to restrain agglomeration of the inorganic-bonding-agent powder, a thickener serving to increase the viscosity of the abrasive-grains-adhering paste for facilitating the printing of the paste on the dressing surface, and a caking agent serving to bond the inorganic-bonding-agent powder to the substrate when the abrasive-grains-adhering paste is dried. It is noted that the dispersing agent, thickener and caking agent are dissipated at the firing step.
Preferably, the present method may further include the step of applying an inorganic-bonding-agent paste on the entirety of the dressing surface of the support body, before the abrasive-grains-adhering paste is printed. In this inorganic-bonding-agent applying step, the inorganic-bonding-agent paste is applied onto the dressing surface of the support body with a sufficiently large amount thereof which permits the first abrasive grains to be bonded to the support body with a sufficiently large bonding strength. Thus, the abrasive-grains-adhering paste is printed with a thickness thereof not so large as where this inorganic-bonding-agent applying step is not implemented, namely, where the first and second abrasive grains have to be fixed to the support body by only the abrasive-grains-adhering paste. In other words, where this inorganic-bonding-agent applying step is implemented before the abrasive-grains-adhering paste is printed, the thickness of the abrasive-grains-adhering paste no longer has to be so large, as long as the thickness of the printed abrasive-grains-adhering paste is sufficiently large for permitting the first and second abrasive grains to merely adhere to the abrasive-grains-adhering paste. Therefore, the operation for printing the abrasive-grains-adhering paste is facilitated without a risk of dripping of the dots of the dotted pattern of the abrasive-grains-adhering paste, which dripping would be caused where the thickness of the printed abrasive-grains-adhering paste is very large.
The dots of the pattern layer are arranged on the dressing surface, preferably, with a density of the dots being constant over the entirety of the dressing surface such that the number of the dots per unit area is constant over the entirety of the dressing surface. This arrangement is effective to substantially equalize loads applied to the respective first abrasive grains, to each other, thereby increasing the polishing efficiency and preventing removal of the first abrasive grains.
Each of the dots preferably has a diameter corresponding to 30-70% of the average diameter of the first abrasive grains, so that each one of the first abrasive grains adheres to the corresponding one of the dots when the abrasive grains are sprinkled over the pattern layer formed on the dressing surface.

Vitrified bond tool and method of manufacturing the same


A module wrapping assembly for a module builder having a first roller rotationally coupled to the module builder about a first axis, a bracket pivotally coupled to the module builder about a bracket axis, and a second roller rotationally coupled to the bracket about a second axis. Wherein, the second axis is offset from the bracket axis. Further wherein, the bracket is pivotable about the bracket axis to reposition the second axis relative to the first axis.

Round module builders or balers use belts and rollers to manipulate harvested material into a desired form. A round hay baler and a round module builder for cotton both typically use belts under tension running on a series of rollers to compact the harvested material into a cylindrical shape. The belts travel along the rollers to generate a forming chamber wherein the harvested material is collected and formed into the desired shape and density. Once the harvested material is formed to the desired size, a wrap delivery system delivers a wrap material into the forming chamber to wrap the module with the wrap material prior to ejecting the module from the forming chamber.
The wrap material is typically distributed from a wrap roll positioned adjacent to the forming chamber. The wrap roll is positioned on rollers and the wrap material is fed through the rollers to ultimately enter the forming chamber. At least one of the rollers is powered at a speed configured to stretch the wrap material as it spans from the rollers to the forming chamber. Often, two rollers are positioned next to one another to pinch the wrap material as it passes there between.

Wrap delivery system with pivoting roller


The present invention relates to a method and a system for manufacturing wafer-like slices from a body of a substrate material, especially for use in the manufacture of semiconductor devices. The method comprises providing a slicing device with a cutting wire equipped on its surface with abrasive particles; providing an aqueous cooling and lubricating fluid, said fluid having an ionic strength corresponding to an electrical conductivity of about 30 IJS/cm or less; cutting said body with said cutting wire into slices while dispensing said cooling and lubricating fluid into a kerf area where said cutting wire contacts and cuts said body, said cooling and lubricating fluid promoting removal of powdered substrate material from said kerf area resulting in spent fluid; and removing said spent fluid from said cutting device and recovering said powdered substrate material from said spent fluid.

The present invention relates to a method and a system for manufacturing wafer-like slices from a body of a substrate material, especially for use in the manufacture of semiconductor devices.
Typically, the substrate material is silicon or other semiconductor material, alone or in combination with other materials.
Conventional methods and systems for manufacturing wafer-like slices from a body of a substrate material use sawing machines to cut the body by abrasion into slices. The substrate material in the saw kerf is disintegrated into powder.
There are two different principles for cutting the body of substrate material into wafer-like slices.
One of the two principles (A) combines smooth wires pulled through the hard substrate material while abrasive slurries composed of a viscous liquid (e.g., polyethylene glycol or mineral oil) and abrasive solid particles (e.g., silicon carbide) provide the means for abrading the substrate material in the saw kerf and additionally act as coolant and lubricant as well as carrier for the disintegrated powdery substrate material.
The other principle (B) uses armed wires which are equipped on their surface with abrasive particles, e.g., diamond particles. An aqueous fluid, typically drinking water, is applied for cooling and lubrication. It also serves as a carrier for the disintegrated substrate material. The armed wires have a larger diameter than the smooth wires used according to principle (A). Therefore, the saw kerf resulting in principle (B) is wider than in principle (A).
The general disadvantage of both principles is the substantial loss of valuable substrate material. In many cases, the saw kerf is approximately as wide as the remaining slices. Hence, about 50% of the valuable material is ground into powdery particles, and only 50% remain as solid wafer components or slices which may be used to produce, e.g., silicon wafers for photovoltaic cells and integrated semiconductor circuits. In view of the high purity and the high costs of many of the substrate materials, this loss results in an enormous waste of material and is also a potential source for environmental pollution.
Principle A further suffers from the contamination of the abrasive slurry that is circulated in the system by ground substrate material (so-called kerf loss), metal traces of the wire and the fines of the abrasive material itself generated by wear. As the degree of contamination of the abrasive slurry grows over time, the efficiency of the sawing operation decreases. When the slurry finally becomes ineffective or exhausted, it is drained from the system and must be discarded and replaced by new slurry or sent to a regeneration process prior to re-use. Moreover, the viscous, spent, contaminated slurry sticks to the wafer surfaces and complicates the cleaning of the wafers after cutting.

Method and system for manufacturing wafer-like slices from a substrate material


Provided is an information transmission method and apparatus. The method applied to a first base station includes: acquiring related information of a terminal, where the related information is uplink information or downlink information, and includes traffic data and/or control information; sending the related information to the second base station through a common transmission channel between base stations. When the related information is uplink information, the first base station is a current serving base station of the terminal, the second base station is a previous serving base station of the terminal, and the uplink information is supplied to the second base station to be decoded. When the related information is downlink information, the second base station is the current serving base station, the first base station is the previous serving base station, and the downlink information is sent to the terminal to be decoded. Further provided is a computer storage medium.

A Long Term Evolution (LTE) network includes an Evolved Universal Terrestrial Radio Access Network (E-UTRAN) and a Core Network (CN). The E-UTRAN includes an evolved Node B (eNB). The CN includes a Mobile Management Entity (MME) and a Serving Gateway (S-GW) and the like. The eNB is connected to the CN via an S1 interface and the eNBs are connected to each other via an X2 interface. One eNB may manage one or more Cells. A User Equipment (UE) is also called as a terminal, an interface between the UE and a cell is called as a Uu port (air interface), and an LTE network architecture can be shown in FIG. 1.
In the existing LTE system, as stipulated in the current protocol, the terminal needs to access a base station to communicate with the base station, that is, the UE initiates a random access process.
To reduce the load of communication equipment or improve the effective utilization of spectrum resources, certain states of some terminals, such as a light connection state or an inactive state, are currently proposed. In such specific state, the connection through the Uu interface between the terminal and the base station is disconnected, but the connection through the S1 interface between the upper layer device and the base station on the network side of the terminal is maintained.
However, how to send uplink information and how to receive downlink information by the UE under such specific state is a problem to be solved in the prior art.

Information transmission method and apparatus, and computer storage medium


A substrate may include: a base material having a predetermined thickness; an electrode section formed on one side surface in a thickness direction of the base material, and having a plurality of electrodes; and a concave section formed on at least a part of the surface on which the electrode section is formed, on the base material.

1. Field of the Invention
The present invention relates to a substrate, and more specifically, to a substrate having a plurality of electrodes formed on a base material to protrude and a semiconductor device using the substrate.
Priority is claimed on Japanese Patent Application No. 2012-081929, filed Mar. 30, 2012, the content of which is incorporated herein by reference.
2. Description of the Related Art
All patents, patent applications, patent publications, scientific articles, and the like, which will hereinafter be cited or identified in the present application, will hereby be incorporated by reference in their entirety in order to describe more fully the state of the art to which the present invention pertains.
A semiconductor device having a three-dimensional structure has attracted interest as an effective structure which avoids various obstacles with which a semiconductor device having a two-dimensional structure has been confronted, such as limits of lithography techniques in miniaturization, increase of wiring resistance caused by miniaturization of a wiring or by increase of wiring length, increase of parasitic effects, tendency of the operation speed to be saturated along therewith, and high electrical field effects due to miniaturization in element dimension, and continues to be improved in integration level by integrating semiconductor elements three-dimensionally in a stacked multi-layer structure by stacking semiconductor active layers.
In manufacturing a semiconductor device having a three-dimensional structure, a stacked-type semiconductor device constructed by bonding wafers having many minute electrodes formed thereon is considered.
For such a stacked-type semiconductor device, in order to protect bonded electrodes, a resin may be injected into a gap between wafers. Here, when many minute electrodes are formed, the gap between wafers becomes smaller and it becomes difficult to inject a resin into the gap. Regarding this problem, techniques for maintaining a gap between wafers by providing an insulating spacer on a stacking surface of a wafer are disclosed in Japanese Unexamined Patent Application, First Publication No. 2010-114350.


The invention relates to a method for determining the change in position of an item of luggage in order to examine a suspect region in this item of luggage.

Currently it is possible to analyze items of luggage completely for explosives. The underlying analysis methods prove very reliable but also laborious. Such a laborious analysis can take place in airports only in so-called third-stage apparatuses. There, the quantity of items of luggage processed is much smaller than with the first- and second-stage apparatuses. With these third-stage apparatuses a high detection rate and a low false alarm rate is required. In order to be able to use such a third-stage apparatus as a second-stage apparatus also, the analysis time must be clearly reduced.
This problem has been solved to date by allowing no physical separation between a first-stage and a second-stage apparatus (see U.S. Pat. No. 5,182,764) or preventing a physical movement or rotation of the item of luggage (see WO 03/065077 A2). However this is very costly and hardly feasible in practice.

Method for determining the change in position of an item of luggage in order to examine a suspect region in this item of luggage


The invention relates to a method and a system for the simultaneous reconstruction of the three-dimensional vessel geometry and the flow characteristics in a vessel system. According to one realization of the method, vessel segments (41) of a parametric models are fitted to differently oriented X-ray projections (P1, Pk, PN) of the vessel system that are generated during the passage of a bolus of contrast agent, wherein the fitting takes the imaged contrast agent dynamics and physiological a priori knowledge into account. In an alternative embodiment, the vessel geometry is reconstructed progressively along each vessel, wherein a new segment of a vessel is added based on the continuity of the vessel direction, vessel radius and reconstructed contrast agent dynamics.

For vascular diseases (e.g. neurovascular, peripheral, or coronary), important diagnostic information is gained from the shape of the vascular system in observation and its flow dynamics. Such information can for example assess tumors, ischemic stenoses, and arterio-venous malformations. A system that allows the such diagnostics is known from the US 2003/0040669 A1, according to which the vessel geometry is reconstructed in three dimensions based on a first sequence of rotational projections. The flow characteristics are then determined from a second sequence of projections from a constant direction, and matched with the three-dimensional vessel model. Due to the necessary generation of two image sequences, the patient load with contrast agent and X-radiation is however rather high for this method. Furthermore, as the dynamic flow is observed in one fixed projection geometry, flow information is only available for a subset of vessels which run approximately parallel to the image plane without occlusion from other vessels, therefore not providing complete diagnostic information.

System for the determination of vessel geometry and flow characteristics


A frequency shift keying modulating circuit produces a first frequency according to a surface acoustic wave transducer natural resonant frequency and a second frequency according to the surface acoustic wave in combination with a reactive element. The frequency selected is determined by the state of a PIN switching diode in parallel with the reactive element.

This invention relates generally to a radio frequency transmitter. More specifically, the invention is related to a low power transmitter having particular utility for use in a remote keyless entry, alarm or similar system for a motor vehicle.
A remote system for a motor vehicle has a base unit in a vehicle and a remote unit carried by the operator. A remote unit is typically low power battery operated and quite small, designed about the size of keychain. Such remote units are generally configured to at least transmit a stream of binary data utilizing known radio frequency transmission modulation techniques. The most common technique utilized in this application is Amplitude Shift Keying (ASK). Experience has shown that ASK may exhibit performance limitations in certain radio frequency hostile environments resulting in reduced range and noise immunity.
One type of alternate radio frequency modulation technique which proves more robust than ASK is Frequency Shift Keying (FSK). Problematic of prior art FSK circuitry is frequency drift and limited separation of generated carrier frequencies. Commonly employed varactor diode frequency pulling techniques yield less than the full frequency separation range possible, exhibits temperature instability characteristic of solid state electronics and requires precise control of a reverse bias voltage applied thereto. Other techniques make use of a multiplicity of reactive element circuit paths for frequency pulling but likewise tend to be temperature drift sensitive and accomplish less than the full range of potential frequency separation. Multiple circuit paths and related switching circuitry reduce overall reliability and increase overall cost due to circuital complexity.


A computer-based virtual assistant the behavior of which can be changed by the user, comprising a voice user interface for inputting information into and receiving information from the virtual assistant by speech, a communications network, a virtual assistant application running on a remote computer, the remote computer being electronically coupled to the user interface via the communications network, wherein the behavior of the virtual assistant changes responsive to user input. A computer-based virtual assistant that also automatically adapts its behavior is disclosed, comprising a voice user interface for inputting information into and receiving information from the virtual assistant by speech, a communications network, a virtual assistant application running on a remote computer, the remote computer being electronically coupled to the user interface via the communications network, wherein the remote computer is programmed to automatically change the behavior of the virtual assistant responsive to input received by the virtual assistant. As detailed below, the virtual assistant adapts to the user in many different ways based on the input the virtual assistant receives. Such input could be user information, such as information about the user's experience, the time between user sessions, the amount of time a user pauses when recording a message, the user's emotional state, whether the user uses words associated with polite discourse, and the amount of time since a user provided input to the virtual assistant during a session.

Mobile professionals, such as physicians, attorneys, sales representatives and other highly mobile professionals often find it difficult to communicate with clients, customers, colleagues and assistants. These mobile professionals travel frequently and are not accessible via a desk telephone or traditional, wired computer network. They typically employ human assistants to relay important information, maintain their schedules and filter out all unnecessary interruptions. The virtual assistant of the present invention allows the mobile professional to access personal, company, and public information, including contacts, schedules, and databases from any interactive device, such as telephone.
Electronic assistants with voice interfaces are known. U.S. Pat. No. 5,653,789 to Miner, et al. discloses a method implemented by a computer-based electronic assistant to receive and manage incoming calls to a subscriber. The electronic assistant in Miner, however, does not disclose a virtual assistant whose underlying behavior can be changed by the user or who has any degree of automatic adaptivity.
Voice response systems (VRS) that automatically adapt to the user are known. For example, U.S. Pat. No. 5,483,608 to O'Sullivan discloses an interactive VRS that automatically adapts to suit the speed at which the caller interacts with the system. The VRS disclosed in O'Sullivan is programmed to measure the response times of the caller and adjust the playing speed of the application dialogue's voice messages accordingly using an algorithm incorporated into the application software of the voice response system. Thus, if the caller is responding relatively fast and without error to the voice message prompts, the system will gradually speed up subsequent voice message prompts. If the caller is responding more slowly to the voice message prompts or is making errors in their responses, the system will slow down subsequent voice message prompts. The system disclosed in O'Sullivan, however, does not perform the actions of a virtual assistant, nor does it permit the user to control how the system adapts.
Another caller adaptive VRS is disclosed in U.S. Pat. No. 5,553,121 to Martin et al. Martin et al. discloses a system for varying the voice menus and segments presented to the user of a voice response system according to the competence of the user. The response time of a user to voice prompts is measured and an average response time is determined. It is assumed that the lower the average response time, the greater the competence of the user. The average response time is used as an index to a table of ranges of response times. Each range has respective voice segments associated therewith. The voice segments comprise oral instructions or queries for the user and vary according to the anticipated competence of the user. If the average response time changes such that the voice segments indexed are different to the current voice segments then a data base containing information relating to user competence is updated to reflect such a change. Accordingly, when the user next interacts with the voice response system a new set of voice segments more appropriate to the user's competence will be played. The system in Martin et al. also discloses determining user competence by identifying individual callers using existing caller identification technology. The call identification code of a telephone call can be used as an index to data stored in a user database comprising information relating to the competence of a user. Alternatively, the user can be asked to enter a password before further access is allowed to the system. The password can then serve as an index to the stored data associated with the user. The stored data identifies which set of voice data is appropriate for use during an interaction with said user. Alternatively, determining the number of times per day that a user accesses the system or the length of time which a user has subscribed to such a system may also be indicative of their competence. Again, VRS disclosed in Martin does not perform the functions of a virtual assistant, nor does it permit the use to have any significant degree of control over the behavior of the system.
Further, while the prior art systems adapt automatically to the caller, the degree of adaptation is relatively limited. For example, the prior art systems do not disclose a virtual assistant that automatically uses words associated with polite discourse when the user's input contains words associated with polite discourse. Prior art systems also do not disclose a virtual assistant that adapts to the user based on the user's emotional state.


Process for producing 6-aminocapronitrile and/or hexamethylenediamine by hydroformylating 3-pentenenitrile, isolating a formylvaleronitrile (FVN) mixture from the hydroformylation reaction product, reductively aminating the FVN mixture and isolating the desired product.

The present invention relates to a process for the production of 6-aminocapronitrile (ACN) and/or hexamethylenediamine (HMD) by a process in which 3-pentenenitrile (3-PN) is hydroformylated to produce a hydroformylation reaction product which contains a mixture of isomers of formylvaleronitrile, isolating the mixture of isomers from the hydroformylation reaction product, and then reductively aminating the mixture of FVN isomers to produce a reductive amination reaction product which contains ACN and/or HMD, either or both of which can be isolated by fractional distillation.
German Patent Application 19631521 discloses a process in which at least one of 2-, 3-, and 4-pentenenitrile is reacted with carbon monoxide and hydrogen in the presence of a catalyst containing at least one Group VIII metal to produce a mixture containing 5-FVN, 4-FVN, and 3-FVN. 5-FVN is first isolated from the mixture and then reacted with ammonia and hydrogen in the presence of a catalyst that contains at least one Group VIII metal to produce ACN and/or HMD. The application discloses the use of distillation as a preferred means of separating 5-FVN from the mixture of 5-FVN, 4-FVN, and 3-FVN.
German Patent Application 19631522 discloses a process for the preparation of ACN and/or HMD by reacting 5-FVN with ammonia and hydrogen in the presence of a catalyst selected from the group consisting of metals or metal compounds of rhenium, copper and elements of Group VIII.
The purification of 5-FVN by fractional distillation from a mixture of 3-, 4-, and 5-formylvaleronitriles can be difficult, due to the instability of the formyl, i.e. aldehyde, group and the level of vacuum necessary to separate and purify the 5-FVN. The instability of the aldehyde group can lead to a loss of FVN due to aldol condensation, and the high vacuum needed for the distillation is impracticable commercially. There is need, therefore, for a process for making HMD and/or ACN in a manner that minimizes 5-FVN loss from aldol condensation, and avoids the need for low pressure fractional distillation to separate 5-FVN from a mixture of 3-, 4-, and 5-formylvaleronitriles.

Process for the production of 6-aminocapronitrile and/or hexamethylenediamine


A light-receiving package for flat-plate mounting which can make monitor reception sensitivity of an optical signal constant without increasing the size of a module. The light-receiving package for flat-plate mounting is provided with a first subassembly in which a photo diode is fixed to a front surface of a retaining holder, a back surface of the retaining holder is a flat surface capable of moving parallel on a plane parallel to a light-receiving surface of the photo diode and a second subassembly which has a rectangular U-shaped concave holder for retaining the retaining holder, and a flat-plate base disposed on a substrate and in which a surface of the flat-plate base that is mounted on the substrate is a flat surface capable of moving parallel to a substrate surface, the rectangular U-shaped concave holder and the flat-plate base are fixed, at least one of surfaces of the concave holder having a rectangular U-shape being a flat surface is a flat surface capable of moving parallel to the back surface of the retaining holder.

A conventional monitor PD 102 has a coaxial structure with a fiber, and, as shown in FIG. 6, an optical signal is tapped to an optical fiber 103 of an optical module 101 to connect the monitor PD 102 by fusion bonding and, thus, to monitor an output of the optical signal (for example, see Patent Literature 1).
FIG. 7 shows a conventional example in which the monitor PD 102 is integrated in the optical module 101 (for example, see Patent Literature 2). In the prior art, the monitor PD 102 is in a form in which a PD bare chip is mounted on a carrier such as ceramic.

Light-receiving package for flat-plate mounting, and optical module

NIPPON TELEGRAPH AND TELEPHONE CORPORATION


In a general aspect, a computer-implemented method can include provisioning a virtual network on a hypervisor server. The method can also include querying the hypervisor server to determine an allowable range for a number of virtual ports of a first port group of a virtual switch implemented on the hypervisor server, the first port group being associated with the virtual network. The method can further include provisioning at least one virtual machine on the virtual network including assigning a respective virtual port of the first port group to the virtual machine. The method can still further include monitoring usage of the virtual ports of the first port group and, in response to the usage of the virtual ports of the first port group exceeding a threshold, instructing the hypervisor server to provision a second port group on the virtual switch, the second port group being associated with the virtual network.

Cloud computing services are generally classified into three "layers", or types of service. These layers, which typically are referred to as conceptually "sitting on top" of one another are, from bottom to top, Infrastructure-as-a-Service (IaaS), Platform-as-a-Service (PaaS) and Software-as-a-Service (SaaS).
IaaS refers to providing virtual computing infrastructure (e.g., cloud-computing infrastructure) resources, such as virtual processors, virtual volatile memory (e.g., random access memory (RAM)), virtual non-volatile memory (e.g., disk storage), virtual networking, etc. For instance, an IaaS provider may own and manage a set of physical computing resources (e.g., in a data center network) that are virtualized through a virtualization layer (which can also be referred to as a hypervisor, a hypervisor server, a virtualization server, etc.). A hypervisor (which can also be referred to as a virtual machine monitor (VMM)) can be implemented as computer software, firmware and/or hardware, which can be used to create (provision) and run virtual machines. A computer on which a hypervisor is implemented and is used to run (host) one or more virtual machines can be referred to as a host machine. Each virtual machine implemented on a hypervisor may be referred to as a guest machine of that host machine.
Clients (users) of an IaaS provider's services can access the virtualized computing resources to implement (provision) virtual servers and/or virtual computers (which can also be referred to, collectively, as virtual machines) including installing (implementing) desired operating systems and/or user software applications on the virtual machines. Such virtualized computing resources can also be used to implement (provision) virtual private networks (e.g., virtual local area networks (VLANs)) and virtual (cloud) data storage.
PaaS refers to providing virtual computing platforms over a network, such as the Internet or private computing networks, as two examples. PaaS providers may provide their customers (users) with virtual computing platforms that include specific, respective operating systems (O/Ss) and runtime environment components. Such PaaS virtual computing platforms can be used for developing and deploying software applications, application hosting, data storage and/or collaboration tools, as some examples.
SaaS refers to providing end-user software applications (services) over a network (e.g., cloud-based application or services). For instance, SaaS providers may provide entertainment and/or business applications to end-users over the Internet using, for example, IaaS and PaaS infrastructures for delivering those services to their customers (users). Some examples of SaaS applications are media streaming (e.g., movies and/or music), business conferencing tools and business productivity (such as word processors, spreadsheet editors, and so forth).
One challenge when providing cloud computing services is efficiently using virtualized computing resources that are provided at an IaaS layer. For example, when provisioning a virtual network using virtualized computing resources that are provided from a hypervisor (virtualization server), it is desirable to provision those resources, such as a number of virtual port groups (each having a number of virtual ports) provisioned, based on expected usage of the virtual network (e.g., an anticipated number of virtual workloads that will be connected at a given time). Over provisioning (e.g., provisioning too many virtual port groups) may result in inefficient use of the available virtual computing resources, as provisioned resources may sit idle.
Likewise, virtual computing resources can be underutilized if a virtual network has available virtual computing resources and available network addresses (e.g., Internet Protocol (IP) addresses) but does not have any available virtual ports to (virtually) connect additional virtual workloads (virtual machines) to the virtual network. Such underutilization can result from a number of factors, such as changes in the available virtual computing resources, the specific configuration of virtual switches that are used to implement the virtual ports of the virtual network, changes in the number of virtual workloads provisioned on a given virtual network, and so forth. Accordingly, alternative approaches for provisioning virtual ports are desirable.


The press-fit section 31 is made up of a lance member 33 for engagement with the latch apertures 26a and 29b of terminal legs 26 and 29 of central and peripheral terminals 3 and 4 and a press-fit portion 36 formed by a pair of linear protrusions 34L and 34R and a pair of pressdown pieces 35L and 35R so that by engaging the lance member 33 with the latch apertures 26a and 29b and holding the terminal legs 26 and 29 between the pressdown pieces 35L and 35R and the linear protrusions 34L and 34R, the terminal leges 26 and 29 are connected to the press-fit terminal 5 with the crimping section 30 crimped on an electrical wire 39.

1. Field of the Invention
The present invention relates to lamp sockets on which lamps, such as automobile headlights, are mounted.
2. Description of the Prior Art
Recently, lamps, such as automobile headlights, which are as bright as daylight, have been developed. Such lamps require that the voltage must rise to high potentials instantly. In order to meet such a requirement, it has been practiced to weld electrical wires to the lamp terminals of lamp sockets for the lamps.
However, such welding requires welding equipment and welding operations, resulting in the high manufacturing costs.


A semiconductor device includes: a semiconductor substrate; an IGBT cell; and a diode cell. The substrate includes a first layer on a first surface, second and third layers adjacently arranged on a second surface of the substrate and a fourth layer between the first layer and the second and third layers. The first layer provides a drift layer of the IGBT cell and the diode cell. The second layer provides a collector layer of the IGBT cell. The third layer provides one electrode connection layer of the diode cell. A resistivity ρ1 and a thickness L1 of the first layer, a resistivity ρ2 and a thickness L2 of the fourth layer, and a half of a minimum width W2 of the second layer on a substrate plane have a relationship of (ρ1/ρ2)×(L1·L2/W22)<1.6.

Inverter circuits for driving loads such as motors correspond to DC/AC converters which convert DC voltages to AC voltages so as to supply the converted AC voltages to the motors, namely the loads. Inverter circuits for driving inductive motors are arranged by, for instance, insulated gate bipolar transistors (IGBTs) corresponding to switching elements, and free wheel diodes (FWDs). In one inverter circuit, an IGBT is employed as a switching element, and an FWD bypasses/circulates a current which flows through a motor while the IGBT is turned OFF in order that the current flowing through the motor is not changed by switching operations of the IGBT. More concretely speaking, a DC power supply is connected to the motor, if the IGBT which has applied the voltage to the motor is turned OFF, then the current which has flown through the motor passes through the FWD to flow as a reverse DC current due to energy stored in an inductance "L" of the motor. Thus, the motor is brought into a status equivalent to such a condition that the reverse DC voltage is applied to the motor. As a consequence, the current of the motor is not rapidly interrupted by switching the IGBT, so that the AC voltage can be essentially applied from the DC power supply by the switching operation.
IGBTs corresponding to the structural elements of the above-described inverter circuits are mainly classified into a so-called "punch through (PT)" type IGBT, a non-punch through (NPT) type IGBT, and a field stop (FS) type IGBT. The field stop (FS) type IGBT is disclosed in JP-A-2004-103982, and corresponds to an intermediate type IGBT with respect to a PT type IGBT and an NPT type IGBT. A PT type IGBT has such a structure that a P conductivity type (P+) substrate having a thick thickness is employed as a collector layer, and an N conductivity type (N+) buffer layer has been inserted between the collector layer and an N conductivity type (N−) drift layer. An NPT type IGBT has such a structure that a P conductivity type (P+) collector layer has been formed on a rear plane of an N conductivity type (N−) substrate (body layer) having a thin thickness and functioning as a drift layer. Also, an FS type IGBT has such a structure that a buffer layer has been inserted between a drift layer and a collector layer of an NPT type IGBT, and the N conductivity type (N−) substrate (body layer) corresponding to the drift layer has be made thinner. The above-described buffer layer is called as a field stop (FS) layer, and N conductivity type carrier concentration has been designed as low concentration.
As previously described, IGBTs and FWDs have been combined with each other in inverter circuits. Very recently, in order to make the above-described inverter circuits compact, such semiconductor devices have been considered which have been manufactured by parallel-forming IGBT cells and diode cells in a single semiconductor substrate. These semiconductor devices have been disclosed in, for example, JP-A-2005-57235 and JP-A-6-196705. JP-A-2005-57235 has disclosed a semiconductor device manufactured by that an NPT type IGBT is formed in combination with a diode. JP-A-6-196705 has disclosed another semiconductor device manufacture by that both an NPT type IGBT and a PT type IGBT are formed in combination with a diode.
FIG. 14 is a sectional view for schematically indicating a conventional semiconductor device 90, namely a semiconductor device manufactured by that a PT type IGBT has been formed in combination with a diode, which is similar to the semiconductor device disclosed in JP-A-6-196705.
In the semiconductor device 90 shown in FIG. 14, an IGBT and a diode cell have been parallel-formed in a single semiconductor substrate 1. In this semiconductor device 90 of FIG. 14, a region 90i surrounded by a dot and dash line corresponds to the IGBT cell, whereas a region 90d surrounded by a two-dot and dash line corresponds to the diode cell. In this drawing, equivalent circuit symbols have been superimposed with respect to the respective regions to be illustrated. The IGBT 90i is expressed as a structure in which an MOS transistor 90m and a bipolar transistor 90b have been connected to each other in a manner as shown in this drawing. A current flowing through the MOS transistor 90m constitutes a base current of the bipolar transistor 90b.
In the semiconductor device 90 of FIG. 14, an N conductivity type (N−) first semiconductor layer (body layer) 1a formed from the major plane of the semiconductor substrate 1 up to the vicinity of the rear plane thereof is a drift layer of carrier of the IGBT 90i and the diode 90d. A P conductivity type (P+) second semiconductor layer 2 formed in a surface layer portion of the semiconductor substrate 1 on the side of the rear plane-thereof is a collector layer of the IGBT 90i (emitter layer of bipolar transistor 90b). Also, in an N conductivity type (N+) third semiconductor layer 3 formed by covering the second semiconductor layer 2, a region 3a functions as a cathode electrode connection layer of the diode 90d, and another region 3b located over the second semiconductor layer 2 functions as a buffer layer 3b of the IGBT 90i. The region 3a is connected to an electrode of the rear plane and is adjacent to the second semiconductor layer 2.
While the IGBT formed in the semiconductor device 90 of FIG. 14 has the PT type IGBT structure having the buffer layer 3b, since the N body layer 1a corresponding to the drift layer of the carrier can be made thinner, there is a merit that an ON voltage which constitutes the basic characteristic of the IGBT can be lowered.
On the other hand, the Inventors of the present patent application could reveal the below-mentioned problem as a result of analyzing of characteristics as to the semiconductor device 90 of FIG. 14. That is, in the semiconductor device 90 having such a structure that the IGBT 90i having the FS layer (namely, buffer layer) 3b and the diode 90d have been parallel-formed in one semiconductor substrate 1, a snap back occurs in a current-to-voltage (Ic-Vce) characteristic which constitutes a basic characteristic of an IGBT.
FIG. 15 is a diagram for schematically representing the above-described problem as to the occurrence of the snap back in the current-to-voltage (Ic-Vce) characteristic.
In a normal IGBT where a snap back does not occur, as indicated by a solid line "XVA" in this drawing, when a voltage VCE is increased from 0 V, a current Ic rises at a threshold voltage VCE(th) of approximately 0.4 to 0.8 V. To the contrary, in an IGBT where a snap back occurs, as shown by an arrow solid line "XVB" of this drawing, even when the voltage VCE is increased from 0 V, the current IC does not rise from the voltage VCE of several V up to approximately 10 V When the voltage VCE reaches an operating point "XVC (VCE1, IC1)", the voltage VCE jumps up to another operating point "XVD" in a discontinuous manner, and the voltage VCE drops, and then, the current IC suddenly rises. This discontinuous characteristic corresponds to a snap back phenomenon. A drop voltage VSB shown in FIG. 15 is referred to as a "snap back voltage."
IGBTs where snap backs occur can be hardly controlled. For example, if a snap back happens to occur in IGBTs which are connected parallel to each other, then a distribution of currents becomes unbalanced. As a result, parallel operations of the IGBTs may be troubled. In such a parallel connection system of these IGBTs, in order that essential trouble does not occur in the parallel operations, the snap back voltage VSB is required to be lower than at least the threshold voltage VCE(th).
In other words, in a semiconductor device manufactured by that an IGBT cell having a low ON-voltage and a diode cell have been parallel-formed in a single semiconductor substrate, it is required to suppress an occurrence of a snap back.

Semiconductor device having IGBT cell and diode cell and method for designing the same


A piezoelectric glass ceramic represented by the formula(M1Ox)-(M2Oy)—SiO2 wherein M1 is one or more metals and/or metalloids, M2 is one or more metals and/or metalloids, x is a value equal to the valence of M1, and y is a value equal to the valence of M2. The piezoelectric glass ceramic has a total alkali metal concentration of less than about 1000 parts per million by weight (ppmw). A process of preparing a piezoelectric glass ceramic and a piezoelectric glass ceramic body prepared therefrom.

1. Field of the Disclosure
The present disclosure is related to the field of piezoelectric materials. More particularly, the present disclosure is related to piezoelectric glass ceramic materials suitable for high temperature applications.
2. Description of Related Art
Piezoelectric sensors and actuators have experienced tremendous growth and wide spread application since the initial work with Pb(Ti,Zr)O3, hereinafter "PZT", in the early 1950's. Since then, PZT-based piezoelectric devices have dominated the world market. They are widely used in underwater sonar, vibration dampening equipment, medical ultrasound transducers, high frequency buzzers and speakers, fuel injection actuators, and precision positioners. These devices have also been incorporated into "Smart Systems" or "Smart Structures," utilizing these device's dual nature as both a sensor and an actuator. Some proposed applications are for variable control surfaces or noise/vibration suppression in aerospace and automotive applications.
However, the current temperature limitations of PZT-based devices have restricted these types of applications. The PZT-based devices are limited by the Curie temperature (TC) of these materials; the temperature indicating the complete loss of piezoelectric properties, typically less than 350° C. It is noted, however, that property degradation typically occurs at temperatures lower than the TC, for example, at approximately ½ TC, associated with an irreversible depoling reaction.
Research has not provided a way to increase the Curie temperature (Tc) for PZT-based materials.
Although devices based on PZT materials have been around for over 50 years, as temperature requirements for particular applications continue to rise, more and more standard materials (e.g, PZT materials) simply do not function at these conditions, particularly above 500° C. This particular temperature range, now actively sought by sensor and device manufacturers, is currently the sole domain of select single crystals, e.g., langatate, langasite, GaPO4 and YCOB and its variants.
Ferroelectric ceramics have been pushed to higher temperatures for well over two decades now, but essentially none are functionally useful at temperatures significantly above 500° C. As indicated above, single crystals have been developed that do seem to meet most or all of the requirements, but these single crystals are expensive to produce.
Piezoelectric glass ceramic materials provide an alternative to conventional piezoelectric materials such as PZT ceramics. Since PZT apart from zirconium and titanium contains lead, piezoelectric glass ceramics have a potential to replace PZT as an alternative lead-free material.
U.S. Pat. No. 7,591,961 discloses lithium-based piezoelectric glass ceramic materials Li2O—B2O3—SiO2 that are translucent at least in the visible light range or in the infrared range. U.S. Patent Application Publication No. 2007/0199348 discloses a method of preparing lithium-based piezoelectric glass ceramic materials Li2O—B2O3—SiO2. While these lithium-based piezoelectric glass ceramic materials are functional at ambient conditions, they are not useful at temperatures above 200° C. due to the high mobility of lithium itself.
These lithium-based piezoelectric glass ceramic materials are not deemed useful for high temperature applications because of their sensitivity to thermal changes, and are not competitive with existing high temperature materials. Therefore, because of these property deficiencies, the lithium-based piezoelectric glass ceramic materials are not considered viable candidates for high temperature applications for state-of-the-art, technically demanding material fields.

Piezoelectric glass ceramic compositions and piezoelectric devices made therefrom


A large pore polyamide resin is useful for large peptide and protein (protide) synthesis. A method of preparing the same comprises mixing a dimethylacrylamide monomer with an unsaturated or alkenoyl amine monomer, a cross-linker and water, homogeneously emulsifying the aqueous mixture with an organic solvent in the presence of an emulsifier, adjusting the pH of the aqueous mixture during polymerization to 6-8.5 to produce large pore resin beads, and isolating the beads. The beads may be used as a solid phase substrate for the synthesis of a polyamide/protide conjugate. The polyamide resin/protide conjugate may be used, without separation of the protide from the resin or subsequent purification, for immunizing mammals, including humans, against the protide, for affinity purifying immunological molecules binding to the protide, and for immunoassays.

1. Field of the Invention
The present invention relates to a large pore resin useful for the synthesis of high MW peptides and proteins (protides) and conjugates thereof, and to the use of the resin/high MW protide conjugate to induce an immune response in experimental animals. More particularly, the present invention relates to a novel large pore polyacrylamide resin, a method of preparing the polyacrylamide resin, a resin/high MW protide conjugate, a method of preparing a resin/high MW protide conjugate, a method of inducing immune response in a mammal with the conjugate, and a method of using the resin/high MW protide conjugate for the affinity purification of antibodies and for immunodiagnostic purposes.

Large pore polyamide resin and method of preparation thereof


A camera detects at least two magnetic tracks accompanying film frames which do not have information recorded thereon. The camera transports the film to place the foremost film frame accompanied with the unrecorded magnetic tracks to a specific position in the camera to avoid double exposure of an exposed film frame accompanied with an unrecorded magnetic track.

1. Field of the Invention
The invention relates to a photographic camera, and, in particular, to a photographic camera which is capable of intentionally rewinding a partly exposed film into a film cartridge and properly setting an unexposed frame of the film in the film cartridge.
2. Brief Description of Related Art
In recent years, a new type of photographic film has been proposed, which has a row of exposure frames accompanied with magnetic recording areas, respectively, and a film cartridge for accommodating the new type of film as shown in Japan Unexamined Patent Publication No. 3-75741. Cameras for use with the film cartridge have been developed which have created a new photographic system with worldwide standards. Some such cameras capable of magnetically recording information on exposure conditions on a magnetic recording area of each frame of the film at every exposure. Therefore, it is possible to recognize how many frames have already been exposed by reading the information on the magnetic recording areas, which makes it further possible to set the foremost unexposed frame of the film partly exposed to the camera exposure aperture (i.e., to use all of the unexposed frames of the reloaded film). However, it may happen that, for one of the exposed frames, magnetic recording is not made at exposure on the related frame or that proper reading of the information on the magnetic recording area is not accomplished. This will cause double exposure if the exposed frame of the reloaded film is placed at the camera exposure aperture.


A selectively doped trench isolation device is provided. The trench isolation device of the preferred embodiment includes a semiconductor substrate having a trench. A thin field oxide layer is grown on the side walls of the trench, and the trench is filled with a heavily doped polysilicon. The work function difference between the substrate and the heavily doped polysilicon increases the field threshold voltage of the gated trench isolation device so that smaller isolation structures can be formed between adjacent active devices in higher density integrated circuits.

1. Field of the Invention
The present invention relates to semiconductor device design and fabrication and more particularly to trench isolation of such devices.
2. Description of the Related Art
In the semiconductor industry, there is a continuing trend towards increasing the number of components formed in an area of an integrated circuit. This trend is resulting in Ultra Large Scale Integration (ULSI devices). This trend is driving the semiconductor industry to explore new materials and processes for fabricating integrated devices having sub-micron sized features so that more devices can be formed in the same area of an integrated circuit. This is particularly true for the manufacture of the Metal Oxide Semiconductor (MOS) or Complementary Metal Oxide Semiconductor (CMOS) Integrated Circuits (ICs).
Such ICs generally consist of an array of active devices such as transistors or capacitors. Typically, each of the capacitors and transistors are separated by an isolation structure that is adapted to electrically isolate adjacent active devices from each other. As device density has increased, the overall dimensions of the capacitors, transistors and the isolation structures on a chip have been reduced by the manufacturers to meet limited space requirements. Moreover, these devices are being placed in closer proximity to each other to increase device density. This situation presents a special challenge for the isolation structures as these devices must be smaller and yet still provide the necessary isolation. In fact, the integrity and the reliability of each active device greatly depends on ability to electrically isolate each active device from adjacent active devices as leakage currents from adjacent devices can result in failure. Thus, despite decreasing dimensions of isolation structures, each isolation structure must still maintain the required degree of isolation to prevent leakage currents between the individual active devices.
Active devices on a chip are generally spaced apart by the regions known as field regions in which the isolation structures are formed. In fact, isolation between the active devices is achieved by interposing the isolation structure, normally called a field device, therebetween to interrupt the parasitic conduction. In particular, it is understood that a difference in potential between adjacent active devices induces charge carriers to travel between the two active devices. The difference in potential is referred to as the threshold voltage required to produce this parasitic conduction.
In many applications, the isolation structure used to inhibit parasitic conduction is formed out of a generally non-conductive oxide material, such as silicon oxide. Preferably, the presence of the isolation structure increases the threshold voltage necessary to produce parasitic conduction to a point where the difference in potential between adjacent active devices never reaches the threshold voltage. This threshold voltage, in the context of isolation structures, is commonly referred to as the field threshold. With these types of isolation structures, the threshold voltage resulting from the formation of the isolation structure is proportionate to the thickness of the isolation structure. Hence, the thicker the structure, the greater the threshold voltage which results in less parasitic conduction during active device operation.
For clarity, the mechanism of parasitic conduction between active devices can be viewed as a parasitic device that is established between active devices. The parasitic device is analogous in operation to a field effect transistor. Consequently, the isolation structure, acting as a gate in a field effect transistor, increases the threshold voltage of the parasitic devices that spontaneously exist between the active devices and prevents inadvertent electrical coupling between the active devices. The goal in any isolation scheme, is to make this field threshold voltage as high as possible without adversely effecting the characteristics of adjacent devices. In the semiconductor industry, this is conventionally done by forming thick isolation structures in the field regions.
Such isolation structures are conventionally formed using processes such as LOCOS (For LOCalized Oxidation of Silicon) or trench isolation. In the LOCOS process, thick isolation structures known as field oxide regions are formed by oxidizing the regions between adjacent active devices. Although the high field threshold provided by such thick field oxide effectively isolates the active devices, the LOCOS process presents some disadvantages associated with the nature of the oxidation process. For example, thick isolation structures formed through oxidation consume a considerable amount of area on the chip limiting the amount of area available for active devices and thereby limiting the active device density. Moreover, during the oxidation process there is lateral encroachment into the active areas of the chip. This lateral encroachment is known as bird's beak encroachment and it further limits the size of the active areas of the chip and the active device density. This bird's beak encroachment remains a significant problem even as device dimensions and isolation structure dimensions are decreased to accommodate higher active device densities.
One alternative to the LOCOS process is known as trench isolation. Advantageously, trench isolation processes do not experience bird's beak lateral encroachment and resulting active area loss. Trench isolation generally involves etching a trench in the substrate between the active devices and filling the trench with an insulator such as silicon oxide. In order to provide high field threshold voltages and to prevent the formation of a conductive channel between neighboring active devices, the trench must have a sufficient depth and width.
However, scaling down trench dimensions to accommodate higher active device densities on an integrated circuit adversely affects the field threshold voltage and can result in parasitic conduction between the active devices. Consequently, while trench isolation techniques generally do not have the lateral encroachment problems associated with LOCOS isolation structures, trench isolation structures must still have relatively large minimum dimensions to maintain adequate isolation between adjacent active devices which inhibits significant increase in device density on an integrated circuit.
One solution to this problem is to use a channel-stop implant to dope side walls of the trench so as to further limit the formation of a conductive channel between the active devices. Channel-stop implants are usually the same dopant type as the dopant type of the substrate, but channel stop implants are implanted in higher doping concentrations to effectively limit the channel formation. However, doping trench walls is a tedious and technically difficult process, and the doped implant often has a tendency to diffuse into active device regions, resulting in undesirable changes in device characteristics.
One other alternative trench isolation method fills the trench with polysilicon. In this method device isolation can be achieved by applying a low bias to the polysilicon so as to prevent channel formation between the active devices. However, as the trench dimensions are reduced, the field threshold voltage of these isolation structures may not be adequately high enough to prevent channel formation. Moreover, as in the case of silicon oxide filled trenches, poly filled trenches may still require side wall channel stop implants.
Thus, in semiconductor integrated circuit technologies, there is need for isolation structures having high field threshold voltages and improved isolation characteristics so as to provide isolation between adjacent active devices in higher active device density applications. To this end, there is a need for isolation structures that reduce channeling between adjacent devices but do not require time consuming doping processes to achieve adequately isolating structures.

This patent is subject to a terminal disclaimer.

Selectively doped trench device isolation