An airship hull is provided that is sufficiently light and cost effective so as to make lifting body type airships practical vehicles for carrying people and cargo. The present invention hull design includes three main structural features, i.e., a rigid internal main frame which carries all primary moment and shear loads induced in the vehicle, the vehicle's skin which forms a semi-rigid barrier membrane for the lighter-than-air lifting gas, and a rigid aeroshell frame interposed between the main frame and the skin. The aeroshell frame and skin, in combination, are referred to as the aeroshell. The aeroshell carries the aerodynamic pressure loads induced on the airship.

1. Field of the Invention
The present invention relates generally to the field of airships or buoyant vehicles and, more particularly, to a lightweight, lift producing, airframe and shell structure ("hull") for a rigid body airship. A lift producing hull is highly advantageous because it allows an airship to take off in a statically negative condition, i.e., in a condition where the hull and payload weight exceed the maximum buoyancy supplied by the lifting gas.
2. Background of the Invention
Airships generate buoyant lift by displacing the surrounding air with a hull containing a lighter than air gas. Generally, there are three conventional types of airships, i.e., rigid, semi-rigid, and non-rigid designs. Most commonly, conventional airships have featured a cigar shaped hull, i.e., an elongated hull of circular cross-section. The conventional rigid airship uses a hull having an internal framework supported by multiple gas bags or cells. Similarly, the hull of a semi-rigid airship typically has a stiff internal lower keel for supporting a gondola underneath. A non-rigid airship on the other hand, has no rigid internal structure to support the hull. To maintain hull shape, semi-rigid and non-rigid airships rely upon lifting gas pressure, i.e., the skin of the hull of both types is primarily composed of a fabric material and the lifting gas has a small positive pressure which maintains the hull's shape. Rigid airships have a rigid external skin and therefore do not rely on lifting gas pressure to maintain structural integrity. At least one of each of the aforementioned conventional types of airship has been constructed and flown in the past.
Of the three conventional types of airships, i.e., fully rigid, semi-rigid and non-rigid, all have one salient feature in common, they depend solely upon the buoyancy generated by the lifting gas to create lift. These designs have numerous disadvantages. Conventional semi and non-rigid airships rely on internal pressure to maintain their form and therefore have limited forward airspeed because air pressure loads deform the nose of the hull. Conventional cigar-shaped rigid airships have the disadvantages of excessive weight due to the frame carrying all of the bending moments and aerodynamic loads. A cigar shaped hull is also unable to produce significant aerodynamic lift which further limits the payload capacity of the airship. Moreover, all conventional airships have the disadvantage of requiring ballast for payload exchange and thus require a ground handling crew to ballast the airship upon landing, further limiting utility.
In all types of airship, the hull may be regarded as a beam loaded by various forces which create moment and point loads in the hull. The first of the forces is buoyancy, where buoyancy is achieved by the lift created by the lighter than air lifting gas. Buoyancy introduces a distributed moment load over the hull. Buoyancy forces act upwardly or positively on the airship's hull. Air ship hulls are also affected by downwardly acting forces. These forces comprise the weight of the hull and any components attached to the hull. Of necessity, airships in addition to the weight of the hull include other downwardly acting weights such as engines, cockpits, fuel tanks, ballast, methods for compressing and storing the lifting gas and the like. Each of these weights introduces point loads into the hull and thereby creates a moment distribution across the surface of the hull. The moment distribution across the hull is further affected by the gas pressure bending moment. The gas pressure bending moment is an effect created by the tendency of helium to collect at the top of the hull, above the neutral axis of the hull which thereby introduces a differential in longitudinal loads (or a bending moment) through the hull.
In recent years, a new class of hybrid airships has been proposed. Hybrid airship designs feature a hull in the shape of a lifting body. These designs have the advantage of being able to generate aerodynamic lift in addition to the lift provided by the lifting gas. With the addition of aerodynamic lift, an airship can take off in a statically heavy condition and can thereby carry a heavier payload then would be possible with a conventional non-lifting body hull. Since substantial forward airspeed is need to generate aerodynamic lift, a rigid hull structure is needed to maintain hull shape under the stress imposed by aerodynamic loads. While rigid lifting body or hybrid airships have been proposed, to the inventors' knowledge, no such craft are presently operational. The reason for the lack of a successful lifting body airship is believed to be because aerodynamic lift introduces additional bending moments into the airship's hull which are substantially greater than those of conventional non-lifting body designs. These additional bending moments require a hull structure substantially stronger and hence heavier than that of a conventional rigid airship. Previously proposed rigid, lifting body airships have proposed hull designs incorporating conventional aircraft technology. These hulls however, if built, would likely prove so heavy as to render the designs nonfunctional much less practical for commercial or military use.
In view of the above, there is a need in the art for a hull design for a rigid, lifting body airship, that is light, simple, inexpensive to build and can readily withstand the loads imposed by aerodynamic lift.


A control system for a tractor with a semi-mounted plough (2) hitched to it comprises a control system (13) for setting a delay between the lifting/lowering of the tractor linkage (3) and the rear of the plough (2) to cause the individual ploughshares to enter to leave work along a given line parallel to a field boundary. To accommodate field boundaries which are not perpendicular to the ploughing direction, adjustment values representative of the angle of each field boundary to the ploughing direction may be entered into a control unit (13) to cause the delay between lifting/lowering of the front and rear of the plough to be adjusted automatically as each field boundary is reached to take account of the angle of that boundary and also whether the plough is being taken out of or put into work.

The present invention relates to a semi-mounted plough control system for an agricultural tractor.
A semi-mounted plough has a support wheel at the center or at the far end on which the plough is supported via a hydraulic cylinder for height adjustment. This means that the height of the near end of the plough, which is mounted on a tractor 3-point linkage and the height of the far end of the plough are controlled by separate hydraulic lines.
It is known, to provide an electronic control system to co-ordinate the lifting and lowering of each end of a semi-mounted plough. Such a system is described fully in U.S. Pat. No. 5,261,495, which is incorporated herein by reference. Using this system, the front end of the plough is caused to enter work before the rear end of the plough so that the diagonally arranged individual ploughshares enter work in the same plane, perpendicular to the direction of travel of the tractor. This makes for even boundaries to the worked area of a field. The same type of control is applied on removing the plough from work.
In the above system, a value is inputted to the control system before ploughing commences which is representative of the length of the plough. The control system uses this value together with the sensed speed of the tractor to determine a time delay between the lowering of the front and rear of the plough into work and a similar time delay between removal of the front and rear of the plough from work. Once the value for the implement length has been input into the control system, it is often not necessary to adjust the settings on the control unit during ploughing. In fact, there are alternative systems which are associated with a particular plough rather than being part of a tractor based control system which will have the implement length value fixed at an appropriate value.
A problem arises, however, when the direction of the furrows is not perpendicular to the field boundaries at each end of the furrows. In this event, to create a neat boundary to the worked area, it is necessary to cause the individual ploughshares to enter work at spaced apart locations with respect to the direction of travel of the tractor to follow the boundary line of the field. It is possible to do this using the known control system, by inputting an adjusted value for the implement length at the beginning of the ploughing operation. This value would be worked out by the operator based on experience so that it takes into account both the actual length of the plough and also the geometry of the field. The problem with this, however, is that this value for "plough length" is only appropriate for one end of the worked area of the field, unless the field boundaries are parallel. Even where the boundaries are parallel, the appropriate "plough length" will be different for entry and exit from work at one end of the field, where a reversible plough is used. Since reversible ploughs are used almost universally now, this means that the "plough length" value needs to be adjusted on every headland turn, at a time when the operator is also having to make a tight turn, change gear and operate lifting/lowering of the linkage. It is difficult for the operator to perform all these functions satisfactorily and this also makes for tiring work because this series of operations has to be performed on every headland turn.


Heat in a stream of combustion products obtained from a glassmelting furnace heated by oxy-fuel combustion is passed to incoming glassmaking materials in a heat exchanger without requiring reduction of the temperature of the stream yet without causing softening of the glassmaking material.

Conventional glassmaking methods require establishing in a glassmelting furnace temperatures that are high enough to melt the glassmaking material (by which is meant one or more materials such as sand, soda ash, limestone, dolomite, feldspar, rouge, which are collectively known as "batch" and/or broken, scrap and recycled glass, known as "cullet"). The required high temperature is generally obtained by combustion of hydrocarbon fuel such as natural gas. The combustion produces gaseous combustion products, also known as flue gas. Even in glassmaking equipment that achieves a relatively high efficiency of heat transfer from the combustion to the glassmaking materials to be melted, the combustion products that exit the melting vessel typically have a temperature well in excess of 2000° F., typically in a range of 2600 to 2950 F, and thus represent a considerable waste of energy that is generated in the glassmaking operations unless that heat energy can be at least partially recovered from the combustion products. The prior art has addressed this problem by using flue gas-to-air heat exchangers known as regenerators. In a conventional air fired regenerative furnace, waste heat in the flue gas is partially recovered in the regenerators by preheating the incoming combustion air and the exit temperature of the flue gas after passing through the regenerators is reduced to about 800 to 1000° F.
Combustion of the hydrocarbon fuel with gaseous oxidant having an oxygen content higher than that of air (which is 20.9 vol. %) (known as "oxy-fuel combustion") provides to the glassmaking operation numerous advantages compared to combustion of the fuel with air. Among those advantages are higher flame temperature and higher available heat without requiring oxidant preheating, which affords higher heat transfer and shorter melting times, and reduced overall volume of the gaseous combustion products that exit the glassmelting furnace, which affords a reduction in the size of the gas-handling equipment that is needed. The combustion products that exit the glassmelting furnace typically have a temperature well in excess of 2000° F., typically in a range of 2500 to 2900 F, and thus represent a considerable waste of energy in spite of its reduced volume. Thus, the gaseous combustion products of oxy-fuel combustion can contain even more heat energy, compared to the large volume combustion products of conventional air-fired combustion with regenerators, which should be used to advantage to improve the overall energy efficiency of the glassmaking operation.
While the glassmaking art is aware of using heat in the hot gaseous combustion products from the glassmelting furnace to preheat incoming glassmaking material which is to be melted in the manufacture of the glass, the heretofore known technology has believed that the temperature of the hot combustion products should not exceed about 1000 to 1300° F. as it commences heat exchange with the glassmaking material. This maximum temperature is imposed by considerations of the capability of the materials from which the heat exchanger is constructed to withstand higher temperatures, and considerations of the tendency of the glassmaking material to begin to soften and become adherent (or "sticky") if it becomes too hot during the heat exchange step, leading to reduced throughput and even plugging of the heat exchanger passages. The temperature at which the glassmaking material becomes adherent or sticky depends on the batch composition and the material in contact with the glassmaking material and is believed to be in a range between 1000 and 1300° F. for a common batch to make soda lime glass for bottles and windows. In a conventional air fired regenerative furnace, the flue gas exit temperature after the regenerators is about 800 to 1000° F. and there is no need to cool down the flue gas prior to a batch/cullet preheater.
When the gaseous combustion products exiting the glassmelting furnace are at high temperatures such as the temperatures obtained by oxy-fuel combustion, the conventional belief has been that they need to be cooled to the range of from 1000 to 1300° F. before heat exchange with the incoming glassmaking materials can commence. Numerous examples exist showing the prior art's belief that the temperature of the flue gas must be reduced before the flue gas is used to heat incoming glassmaking materials. Such examples include C. P. Ross et al., "Glass Melting Technology: A Technical and Economic Assessment", Glass Manufacturing Industry Council, August 2004, pp. 73-80; G. Lubitz et al., "Oxy-fuel Fired Furnace in Combination with Batch and Cullet Preheating", presented at NOVEM Energy Efficiency in Glass Industry Workshop (2000), pp. 69-84; U.S. Pat. No. 5,412,882; U.S. Pat. No. 5,526,580; and U.S. Pat. No. 5,807,418.
However, reducing the temperature of this stream of combustion products by adding to it a gaseous diluent such as air, and/or spraying a cooling liquid such as water into the stream, is disadvantageous as such approaches reduce the amount of recoverable heat remaining in the gaseous combustion products, increase the size of the gas handling equipment that is needed, and adds additional equipment and process expense.

This patent is subject to a terminal disclaimer.

Heating glassmaking materials with radiative heat transfer


A multi-layer structure roller includes a tubular-shaped metal-made outer cylinder section located at the outer-most position, a tubular-shaped metal-made middle cylinder section located on the inside of the outer cylinder section, and an tubular-shaped metal-made inner cylinder section located on the inside of the middle cylinder section, in which coefficient of linear expansion of the middle cylinder section is greater than the coefficient of linear expansion of the outer cylinder section, the outer cylinder section and the middle cylinder section are coupled by using the difference in heat-expansion caused by heating both cylinder sections in the state sandwiching an elastic body between both cylinder sections to be laminated, tapers are respectively provided at the inner circumference of the middle cylinder section and the outer circumference of the inner cylinder section to fit the taper of the middle cylinder section, certainly coupled with the outer cylinder section to sandwich the elastic body by expanding with heating, the taper of the inner cylinder section, being in the cooling shrinking state or the room-temperature state, and further, the middle cylinder section and the inner cylinder section are combined in the fitted state of the tapers with prevention from shrinkage caused when the middle cylinder section is changed to the room-temperature. The middle cylinder section can be attached onto the outer circumference surface with an elastic body.

1. Field of the Invention
This invention relates to a multi-layer structure roller and a method for producing the same, which is capable of being used for forming a roller used in order to carry out a polishing (gloss) process or an embossing (grained pattern) process on the surface of a thermoplastic resin sheet (or film) or a roller in order to make a film of an extremely thin film.
2. Description of the Related Art
Conventionally, when making or processing a film of a thermoplastic resin sheet (or film), especially, when forming a sheet by cool-caking the melted or softened resin film, and simultaneously, carrying out a polishing (gloss) process or an embossing (grained pattern) process, a rubber roller and a metal roller formed with a mirror face or an emboss face (a face having an asperities pattern) are used generally.
FIG. 6 shows a general situation when the process is carried out by using a metal roller 80 and a rubber roller 81 as described above. In the case of FIG. 6, a demineralizating-range or melted sheet is pressed between the metal roller 80 and the rubber roller 81 to be pressed with each of rollers 80 and 81, thereby the emboss pattern or polishing on the surface of the metal roller 80 is transferred onto the sheet 82. At this time, the rubber roller 81 is deformed elastically, whereby a surface-rolled area 84 formed by the metal roller 80 and the rubber roller 81, which sandwich the sheet 82, is to be surface-rolled.
The case of FIG. 6 has the following advantage. That is, generally, when the sheet is transferred by pressing between a combination of the higher-degree metal roller and the metal roller, the surface-rolled consists only of lines, whereby the transfer is not sufficient. However, in the case of FIG. 6, the surface-rolled area 84 is to be rolled because of the elastic deformation of the rubber roller, resulting in sufficient transfer.
As shown in FIG. 7, the process may be carried out by providing a metal-made endless belt 92 between a metal roller 90 and rubber roller 91. In FIG. 7, the metal-made endless belt 92 is wound and hitched between the rubber roller 91 and a cooling roller 93, in which the surface of the endless belt 92 is a mirror face or an emboss face. A sheet 94 is pressed between the rubber roller 91, wound with the endless belt 92, and the metal roller 90, having the mirror face or the emboss face. The endless belt 92, wound on the rubber roller 91, and the metal roller 90 are pressed on the sheet 94 to transfer the polishing or the emboss pattern on the metal roller 90 or the endless belt 92 onto the sheet. At this time, the rubber roller 91 is elastically deformed, with the result that a surface-rolled area 95, formed between the metal roller 90 and the endless belt 92 (the rubber roller 91) in the state that the sheet 94 is sandwiched between them, is to be surface-rolled. Therefore, the case shown in FIG. 7 has an advantage of obtaining sufficient transfer.
However, when the process is carried out by using the metal roller 80 and the rubber roller 81 as shown in FIG. 6, produces a disadvantage whereby the surface of the sheet 82 rolled with the rubber roller 81 becomes rough. Further, another disadvantage is produced, in which the sheet 82 is crumpled by increasing the temperature of the rubber roller 81, namely, deficiency by exfoliation of the sheet.
When the process is carried out by using the endless belt 92 as shown in FIG. 7, for the endless belt 92 as an intermediate, the sheet 94 and the rubber roller 91 are not directly rolled, resulting in no disadvantages such as deficiency by exfoliation or the rough face as shown in FIG. 6.
The method used for carrying out the process using the endless belt 92 as the intermediate is an extremely effective method, however, the method produces a disadvantage in that the apparatus increases in complexity and cost. Further, another disadvantage, a snake-inhibiting device for preventing the endless belt 92 from snaking, is needed. And still another disadvantage, the device has to be larger in order to increase the endurance of the endless belt 92.
It is extremely difficult to process the aforementioned precision emboss process (the emboss of about 10-100.mu.) onto the metal roller or the surface of a metal plate. In some cases, only engraving onto the small area (e.g., 9 inch.times.9 inch) of the metal plate is possible, therefore, the engraved metal plate is used as a transferring plate or as an original plate of a replica in order to be used as the transferring plate replicated by, for example, electro-forming (a sculpturing method for correctly replicating the same metal model as the original plate by applying electroplated coatings).
The aforementioned transferring plates are all flat plates, thereby the micro-emboss sheet should be produced with use of a batch type of, for example, vacuum press, resulting in the disadvantage of critically low productivity.
As a consequence, in order to dramatically increase the productivity of the micro emboss sheet, a method has been required, in which the transferring plate of the flat plate is processed to a roller-shape to securely form a required micro emboss roller.

Multi-layer structure roller and a method for producing the same


Motion sensing dock lighting systems are disclosed. An example lighting system for use at a loading dock where a material handling device is used to load or unload a vehicle parked at the loading dock includes a motion sensing system to be spaced apart from the material handling device. The motion sensing system is to provide an operation signal in response to the material handling device undergoing a change in travel direction within the vehicle. The example lighting system also includes a lamp to be operatively connected in signal communication with the motion sensing system so as to receive the operation signal from the motion sensing system. The lamp is to have a first illuminating mode and a second illuminating mode, and the lamp is to switch between the first illuminating mode and the second illuminating mode in response to the operation signal.

Some loading docks of a building include an exterior doorway with an elevated platform for loading and unloading vehicles, such as trucks and trailers. To compensate for height differences between the loading dock platform and an adjacent bed of a truck or trailer, many loading docks have a dock leveler. Some dock levelers include a deck or ramp that is pivotally hinged along its back edge to vary the height of its front edge. An extension plate or lip extends outward from the deck's front edge to span the gap and thus create a bridge between the rear of the truck bed and the front edge of the deck. This allows personnel and material handling equipment to readily move on and off the vehicle during loading and unloading operations.
If the truck or trailer is enclosed, as opposed to being an open flat bed trailer, the inside of the trailer can be quite dark, making it difficult to see deep inside the trailer. So, a light fixture pointing into the trailer can be installed and used near the doorway of building. Such light fixtures are available in various shapes and sizes.


A tool for use with a canning pot and a canning rack includes a pair of spaced-apart legs joined at a handle adapted for manipulation by a user. The spaced-apart legs terminate at a hook, which is adapted to grasp the rack and operable to place and remove the rack in the canning pot. A canning system includes a canning pot, a canning rack, and a rack lifter including a pair of tools, each including a pair of legs joined by a handle and terminating in a hook operable to grasp the rack. A method for canning food includes heating a first quantity of water in a canning pot, placing at least one jar in a canning rack, and placing the canning rack including the at least one jar in a first quantity of water using a pair of tools for selectively grasping the canning rack.

Canning is a safe and economical way to preserve food quality at home. Canning home-grown food may save you significant money when compared to buying commercially canned food. Further, canning favorite and special products to be enjoyed by family and friends is often a fulfilling experience and a source of pride for many people. Moreover, if vegetables are handled properly and canned promptly after harvest, they can be more nutritious than fresh produce sold in local stores.
Because of the high percentage of water in most fresh foods, they are very perishable and spoil or lose quality because of the growth of undesirable microorganisms, such as bacteria, molds, and yeast; the activity of food enzymes; reactions with oxygen; and moisture loss. Microorganisms live and multiply quickly on the surfaces of fresh food and on the inside of bruised, insect-damaged, and diseased food.
Proper canning practices, however, can mitigate the perishable qualities of food. Proper canning practices include carefully selecting and washing fresh food; peeling some fresh foods; hot packing many foods; adding acids (lemon juice or vinegar) to some foods; using acceptable jars and self-sealing lids; and processing jars in a boiling-water or pressure canner for the correct period of time. Collectively, these practices remove oxygen; destroy enzymes; prevent the growth of undesirable bacteria, yeasts, and molds; and help form a high vacuum in jars. Good vacuums form tight seals, which keep liquid in and air and microorganisms out.
Many canning practices are concerned with preventing the growth of the bacterium Clostridium botulinum, which may cause botulism, a deadly form of food poisoning. Botulinum spores are found on most fresh food surfaces but, because they grow only in the absence of air, are harmless in fresh foods. Thus, most canning processing times ensure destruction of the largest expected number of heat-resistant microorganisms in canned foods, including botulinum spores. Properly sterilized canned food will be free of spoilage if lids are sealed and jars are stored below 95° F.
Further, whether food should be processed in a pressure canner or boiling-water canner to control botulinum bacteria depends on the acidity of the food. Acidity may be natural, as in most fruits, or added, as in pickled food. Low-acid canned foods are not acidic enough to prevent the growth of these bacteria, while acid foods contain enough acid to block their growth, or destroy them more rapidly when heated. The term "pH" is a measure of acidity; the lower its value, the more acid the food. The acidity level in foods can be increased by adding lemon juice, citric acid, or vinegar.
Low-acid foods have pH values higher than 4.6. They include red meats, seafood, poultry, milk, and all fresh vegetables except most tomatoes. Most mixtures of low-acid and acid foods also have pH values above 4.6 unless their recipes include enough lemon juice, citric acid, or vinegar to make them acid foods. Acid foods have a pH of 4.6 or lower. They include fruits, pickles, sauerkraut, jams, jellies, marmalades, and fruit butters.
Botulinum spores are very hard to destroy at boiling-water temperature; the higher the canner temperature, the more easily they are destroyed. Therefore, all low-acid foods should be sterilized at temperatures of 240° to 250° F., attainable with pressure canners operated at 10 to 15 pounds per square inch of pressure as measured by gauge (PSIG). At temperatures of 240° to 250° F., the time needed to destroy bacteria in low-acid canned food ranges from 20 to 100 minutes. The exact time depends on the kind of food being canned, the way it is packed into jars, and the size of the jars. The time needed to safely process low-acid foods in a boiling-water canner ranges from 7 to 11 hours; the time needed to process acid foods in boiling water varies from 5 to 85 minutes.
Accordingly, it is very important in the art of home canning to destroy undesirable bacteria such as Clostridium botulinum by processing the cans in a pressure canner or boiling-water canner. But using such high-pressure and high-heat devices presents other safety concerns to users, such as the handling of equipment used in the canning process. One such concern is with the handling of canning racks, which are used to submerse the jars in two main types of canners for heat processing home-canned foods; boiling-water canners and pressure canners.
For example, when handling jars in a conventional canning process, jar lifters are used to individually place and remove jars in a rack of the canner. The rack positions the one or more jars in the canner such that water substantially surrounds each jar. While the rack is removable from the canner, the jar lifters are used to place the jars in the rack and remove the jars from the rack because, typically, the rack is at least partially submersed in hot water. Thus, to avoid injury to the user from the hot water, the jar lifters provide a safe way to move the jars to and from the hot water. This process suffers from the inefficiency that only a single jar may be removed at one time, despite the fact that the rack itself is removable from the canner.


An insulating film comprising an organic silicon material having a C—Si bond and a Si—O bond is used for a semiconductor integrated circuit, and for polishing of its surface, a polishing compound comprising water and particles of at least one specific rare earth compound selected from the group consisting of a rare earth oxide, a rare earth fluoride, a rare earth oxyfluoride, a rare earth oxide except cerium oxide and a composite compound thereof, or a polishing compound having the above composition and further containing cerium oxide particles, is used. It is possible to provide a high quality polished surface which is free from or has reduced defects such as cracks, scratches or film peeling.

In recent years, low power and high speed are required for semiconductor integrator circuits, and drastic increase in density and high densification are required, and multilayered structures of circuits and miniaturization of wiring patters by e.g. copper or aluminum are in progress.
With respect to the multilayered structures of circuits, the irregularities on the surface of a circuit formed by e.g. exposure, has an influence over a circuit to be formed thereon in a multilayered structure. This influence tends to be significant in the wiring pattern at the upper layer, and makes it difficult to satisfy both resolution and depth of focus in photolithography, or causes a defect such as breakage of wire of the circuit.
Accordingly, an insulating film formed on a semiconductor substrate is planarized by chemical mechanical polishing (CMP), and a new wiring is optically exposed by photolithography to form a circuit thereon, and such an operation is repeatedly carried out to laminate circuits.
In this CMP, the irregularities on the surface to be polished have to be flattened by polishing in as short time as possible and at the same time, defects on the semiconductor substrate surface at the time of polishing, such as cracks, scratches or film peeling, which cause the irregularities on the surface to be polished, have to be suppressed as far as possible.
On the other hand, by miniaturization of processing line width by miniaturization of the wiring pattern by using e.g. copper or aluminum, due to narrowed space between wirings, the capacitance between wirings tends to increase, the signal delay time tends to be long, and the increase in speed of a semiconductor integrated circuit will be inhibited. Thus, insulation between wirings is carried out by tightly filling e.g. the space between such miniaturized wirings with a material having a low dielectric constant.
Heretofore, as a material of an insulating film, inorganic material such as a SiO2 film having a relative dielectric constant of about 4.2 has been used (e.g. JP-A-06-216096 (paragraphs 0172, 0173), JP-A-10-94955 (paragraph 0028), JP-A-2000-79564 (paragraph 0011)). However, in recent years, due to further increase in density of wirings, an insulating film having a dielectric constant lower than ever is required.
Such an insulating film, an organic silicon material film having a C—Si bond and a Si—O bond is proposed. Such an organic silicon material film having an C—Si bond and a Si—O bond can not be said to have high mechanical strength as compared with a conventional SiO2 film, however, it generally has a low dielectric constant, comparable in thermal stability and has characteristics exceeding a conventional SiO2 film in many points such as a property to form a flat surface at the time of film formation, and a characteristic to fill the gap at the time of film formation.
When such an organic silicon material having a C—Si bond and a Si—O bond, which is used as an insulating film for example, is polished with a conventional polishing compound comprising particles of e.g. silica, alumina or ceria as abrasive grains and water as a main medium, if polishing is carried out under the same pressure (2.8×104 to 3.4×104 Pa) as in a case of polishing a conventional insulating film made of an inorganic material so as to obtain a high polishing speed (polishing rate), defects such as cracks, scratches or film peeling, which may cause the irregularities on the organic silicon material film having a C—Si bond and a Si—O bond in some cases. This is considered to be a phenomenon resulting from low mechanical strength of the organic silicon material film having a C—Si bond and a Si—O bond as compared with an inorganic material insulating film. Further, if the pressure during polishing is decreased to prevent such defects, no adequate polishing speed could be obtained.
Further, in the case of ceria which is used as widely as silica as abrasive grains for a conventional SiO2 film, the polishing speed was found to significantly decrease when used for polishing the organic silicon material film having a C—Si bond and a Si—O bond.
As mentioned above, an appropriate polishing compound has not been found for an insulating film comprising an organic silicon material having a C—Si bond and a Si—O bond, which is a bottleneck in effective production of a multilayered semiconductor integrated circuit.

Polishing compound for insulating film for semiconductor integrated circuit and method for producing semiconductor integrated circuit


A woven fabric is wove using warps (6) and wefts (7) having coated threads (6a) and (7a), respectively, every other thread, with the remaining threads being uncoated threads (6b), (6c). The coated threads (6a), (7a) are melted by a heat setting treatment, thereby fusing the coated threads (6a) in the warps (6) to the wefts (7) and the coated threads (7a) in the wefts (7) to the warps (6). The woven fabric becomes an uncoated woven fabric on which a thin coating film has not been formed. Accordingly, the uncoated woven fabric has a predetermined amount of air permeability. The threads will not become frayed or tattered and the amount of air permeability will not change even when the uncoated woven fabric is cut.

This invention relates to an uncoated woven fabric, which comprises a woven fabric, ideal for use in an air bag for vehicles or the like, as well as a method of manufacturing the uncoated woven fabric.
An air bag device provided on a stationary portion of the vehicle body of an automobile in front of a seat of the automobile has an air bag inflated instantaneously by the pressure of a reaction gas emitted by an inflator secured to the steering wheel or dashboard, thereby protecting a seated passenger from injury caused by a vehicular collision. Thus, the air bag device performs a very important function.
The shape of the air bag in such an air bag device differs depending upon the location at which the air bag is mounted. For example, as shown in FIG. 6, an air bag 1 for the driver's seat comprises a substantially circular bag body having a disk-shaped base fabric 1a attached to a fixed portion of the vehicle body, such as the steering wheel, and a circular base fabric 1b facing the driver. The base fabrics 1a, 1b are superimposed and sewn together at A along their circumferential edges and turned over. The air bag 1 has an opening 2 provided in the base fabric 1a, which is secured to the vehicle body, into which the inflator (not shown) that generates the reaction gas is inserted. The air bag 1 is further provided with vent holes 3 from which the reaction gas is discharged after the driver is impacted against the air bag 1.
As shown in FIG. 7, a passenger air bag 4 is provided in the instrument panel and has a complicated shape owing to the fact that the space between the assistant driver's seat and the instrument panel is large. The passenger air bag 4 includes a front panel 4a, a rear panel 4b and a pair of side panels 4c, 4d. The edges of these panels are overlapped and sewn together and turned over to form the air bag 4.
In general, the driver and passenger air bags 1, 4 both consist of a synthetic resin such as polyimide resin and are formed from a suitable number of base fabrics in which a thin coating film 5 (shown only on the driver's air bag 1 in FIG. 6) of chloroprene rubber or silicone rubber is provided on the inner surface. By providing the thin coating film on the inner surface of the base fabric, the base fabric is protected from the high temperature and high pressure of the reaction gas jetted from the inflator when the air bag is inflated.
In order to lighten the air bag device and make it more compact, there has recently been greater demand for an air bag base fabric that can lighten the air bag and reduce the volume of the package. Since progress has been made in lowering the temperature of the reaction gas by virtue of an improvement in the performance of the inflator and the development of aspirator-type air bag devices, air bags which use a fabric on which a thin coating film is not formed (such a fabric shall also be referred to as an "uncoated fabric" hereinafter) have become the focus of interest. Since the uncoated fabric does not have a thin coating film such as chloroprene rubber or silicone rubber formed thereon, the thickness of the base fabric is reduced by an amount equivalent to the thickness of the thin coating film, and therefore the air bag is reduced in both weight and package volume.
In a case where an uncoated woven fabric is used, there are occasions where the threads of the uncoated woven fabric become frayed or tattered when the fabric is subjected to cutting. In general, when such an uncoated woven fabric is subjected to a heat-resistance aging test in which it is maintained at a temperature of 80.degree..about.120.degree. C. for 600.about.1000 hrs, the threads becomes ball shaped owing to contraction of the threads and locations are produced where the spaces between threads widen and other locations where the spaces become small. As a result, there are instances where there is a change in properties, such as a change in the amount of air permeability of the base fabric.

Uncoated woven fabric and method of manufacturing same


A method is disclosed for testing pinned layers of magnetic disk drive read heads having at least one pinned layer, where the magnetic orientation of the pinned layers has been set in an initial direction. The method includes applying a large magnetic test field at a reverse canted reset angle. First test responses from the disk drive read heads are then measured in a small magnetic test field. A large magnetic test field is applied at normal canted reset angle. The disk drive heads are then subjected to a full suite of performance tests in a small magnetic test field to verify their acceptability. These second test responses are then compared to the first test responses to identify read heads having weakly pinned layers.

1. Field of the Invention
The present invention relates generally to magnetic storage devices and particularly to hard disk drives having magnetic heads including pinned magnetic layers within a read head sensor.
2. Description of the Prior Art
A computer disk drive stores and retrieves data by positioning a magnetic read/write head over a rotating magnetic data storage disk. The head, or heads, which are typically arranged in stacks, read from or write data to concentric data tracks defined on surface of the disks which are also typically arranged in stacks. The goal in recent years is to increase the amount of data that can be stored on each hard disk. If data tracks can be made narrower, more tracks will fit on a disk surface, and more data can be stored on a given disk. The width of the tracks depends on the width of the read/write head used, and in recent years, track widths have decreased as the size of read/write heads has become progressively smaller. This decrease in track width has allowed for dramatic increases in the areal density data storage density of disks.
For reading the magnetic data stored on the disks, a sensor called a spin valve is commonly used which includes one or more ferromagnetic pinned layers and a ferromagnetic free layer. The first pinned layer is generally fabricated on an antiferromagnetic (AFM) pinning layer which fixes the magnetic moment of the pinned layer at an angle of 90 degrees to the air bearing surface (ABS). In this type of MR sensor, the resistance of a layered magnetic sensor varies due to both spin-depending transfer of conduction electrons between the pinned magnetic layers and the free layer through a non-magnetic spacer layer, and spin-depending scattering at the interfaces between the layers accompanying the transfer of conduction electrons. The in-plane resistance between the pinned ferromagnetic layers and the free layer, which are separated by the non-magnetic spacer layer varies in proportion to the cosine of the angle between the magnetization in the free and pinned layers.
In ferromagnetic materials, scattering of electrons depends on the spin of the carriers. Resistivity is proportional to the scattering of electrons. Electrons with spins parallel to the magnetization direction experience very little scattering and hence provide a low-resistance path. If magnetization of part of this layer structure is pinned and the magnetization of the free layer is gradually rotated from a parallel to an anti-parallel direction, the resistance of the structure increases in proportion to the cosine of the angle of magnetizations of the layers. This change in resistance is thus used to read the data bits on the disk.
The sensitivity of a magnetoresistive sensor is quantified as magnetoresistive coefficient dr/R where dr is the change in resistance of the tunnel junction sensor from minimum resistance to maximum resistance and R is the resistance of the tunnel junction sensor at minimum resistance.
As referred to above, it is common practice in the industry to pin the pinned layer by using a layer of anti-ferromagnetic (AFM) material, but in recent years there have been structures developed which are "self-pinned", such that the sensor can dispense with the AFM layer.
Since it is the angle of magnetization between the free and the pinned layers that enables the data to be read, and since the free layer magnetization must be free to change direction with the magnetic orientation of the data-bits, it is the pinned layers that provide the steady foundation for the magnetization angle. If the pinned layer orientation changes from its correct, fixed direction, the angle between the magnetization directions in the pinned layers and the free layer changes, causing the output characteristics of the read head to deteriorate. It is of crucial importance therefore that the magnetization of the pinned layers remain stable and unchanging.
Weakness of pinning in the pinned layer is thus of concern in the manufacturing of disk drive and disk drive components. The factors which cause the strength of the pinned layer to degrade are not completely understood, but it is thought that such factors as mechanical stress caused by head/disk interaction, and electrical stress caused by electrical transients or by temperature fluctuations may contribute to this weakness. At its extreme, there the read head signal can flip its sign (positive to negative or vice versa). This is becoming a growing problem in read sensors in which the elements are becoming so miniaturized that the superparamagnetic limit for magnetic materials is being approached.
At present, there is no method for testing the strength of pinning of the pinned layers which is used for mass production. The strength of the pinning is a vital factor in the overall performance and reliability of the read head, and thus, of the disk drive as a whole.
Thus, there remains a great need for a method that can test the strength of pinning of the pinned layers at an early stage in the manufacturing process, so that weak components can be screened out, and the overall reliability of the read heads and thus of the entire hard disk drive may be enhanced.

Reverse magnetic reset to screen for weakly pinned heads

Hitachi Global Storage Technologies Netherlands, B.V.


A fixture, system, and method for coating a glove with a coating material are described. A fixture includes a support member and a clamping member movable relative to the support member to a closed position. The clamping member is configured to be at least partially received in a cuff of the glove. In the closed position, the cuff is captured between the clamping member and the support member. In this configuration, a majority of an external surface of the glove is exposed for being coated. A glove-coating system can include one or more fixtures on a conveyor that move the fixture around various processing stages of the glove-coating system. In certain methods of coating a glove, coating material is applied to the glove while the glove is suspended from the fixture. The coated glove can be removed from the fixture without being everted.

In certain conventional processes for making plastic gloves, hand molds are dipped in a coagulant solution before being coated with a polymer for forming the glove (e.g., a latex, a vinyl, a nitrile, etc.). The liquid glove material is then cured in an oven, and the cured glove is everted to separate the glove from the mold. Because the glove is everted when removed from the mold, it is not possible to apply an exterior coating (e.g., an anti-microbial coating or the like) to an external surface until after the glove is removed from the mold. Thus, secondary processes are used to apply coating materials to the external surfaces of plastic gloves.

Fixture, system, and method for coating plastic glove


The invention provides a method and process for transmitting data without using additional CPU cycles and memory accesses to calculate checksums. The transmitting device obtains data from internal or external data source and stores data in memory. Data is then divided into zones and checksums are calculated for each zone. Checksums are recorded on a checksum array. A data pointer containing an address for data stored in memory, a description of the data and address for the checksum array is transferred through data transfer protocol to network and transmission layers. Network and transmission layers are then able to access and send data without having to either copy data through data transfer protocol to network and transfer layers or read all of the data to calculate the checksums. This method and process uses fewer CPU cycles and memory accesses to transmit data and is, therefore, more efficient than the prior art.

1. Field of the Invention
This invention relates to the transmission of data through a communications network and incorporates a unique process for calculating data checksums.
2. Related Art
In computer networks, data is often transmitted from one computer to another using a data transfer protocol. Some of the major protocols in use include Open Systems Interconnection (OSI), Transfer Control Protocol/Internet Protocol (TCP/IP), Decnet, Telnet, XNS, IPX, AppleTalk and others. The invention is intended to work with protocols now in existence or protocols which may be developed in the future, but the invention is particularly useful when the protocol uses a checksum which may be defined to allow transfer of data in small pieces.
The transmitting computer obtains the data to be transmitted from a data source (such as a hard disk, DMA or other source) and caches the data in memory. The data is then copied from the application layers to the network layers and ultimately transmitted to the communications network.
One problem is that copying the data through a data transfer protocol takes numerous CPU cycles and memory accesses and, thus, slows the transmission process. A method that is sometimes used to avoid copying the data through data transfer protocol is creating a data pointer in the application layer and sending that pointer to the network and transmission layers instead of copying the data itself. Fewer CPU cycles and memory accesses are used to transmit the data pointer than to copy the data itself. The network layers use the data pointer to locate the data cached in memory and transmit it through the communications network.
One problem with the method of using a data pointer to speed up the transmission process is that it is that much of the efficiency of transferring the data pointer is lost when the transport layer subsequently needs to read all the data to calculate the checksum. It takes fewer CPU cycles and memory accesses to transfer a data pointer than to copy data through protocol. But CPU cycles and memory accesses are required to read the data cached or stored in memory in order to calculate the checksums. Thus, the economy otherwise gained by transferring a data pointer instead of copying data is diminished because the CPU cycles and memory accesses are required to read the data to calculate the checksums.

System to limit access when calculating network data checksums


This invention provides an undercoating layer material and a filler material containing a resin component having at least a substituent group which is capable of releasing a terminal group to form a sulfonic acid residue upon application of predetermined energy, and a solvent. The resin component has at least a repeating unit represented by formula (1):

1) Field of the Invention
The present invention relates to an undercoating material used preferably for forming wiring on a semiconductor substrate, a filler material and a wiring formation method using the same. The undercoating material referred to herein indicates (a) an undercoating layer which is formed on a substrate before formation of a photoresist layer on the substrate whereby a reflected exposure light from the surface of the substrate at the time of patterning of a photoresist is prevented from entering the photoresist, to achieve improvement in the resolution of the photoresist pattern, (b) an undercoating layer suitable for a silicon bilayer resist, which is characterized by improving the patterning accuracy of a resist by constituting a photoresist layer used in lithography for wiring, from two layers, that is, an undercoating layer including an organic film and a silicon-containing upper resist layer, and (c) an undercoating layer suitable for multilayer process, which improves the patterning accuracy of a resist by constituting a photoresist layer used in lithography for wiring, from a multilayer structure including at least an undercoating layer including an organic film, an intermediate layer, and an upper photoresist layer. The filler material referred to herein indicates (d) a material for filling an etching space for forming a dual damascene structure composed at least of a first etching space formed in a low-dielectric layer on a substrate and a second etching space communicating with the first etching space and different in shape and dimension to those of the first etching space.
2) Description of the Related Art
As is well-known, a semiconductor substrate includes a dielectric layer (insulating layer) laminated on a substrate such as silicon wafer, wherein a semiconductor wiring structure is constituted by forming a patterned conductive layer (wiring layer) in the dielectric layer on the semiconductor substrate.
For formation of the wiring structure, two methods are mainly used. The first method involves forming a conductive layer uniformly on the dielectric layer, then forming a photoresist on the conductive layer, irradiating (light-exposing) the photoresist with a pattern light and develop it to form a resist pattern, patterning the conductive layer by etching using the resist pattern as a mask to form a wiring layer, removing the resist pattern and laminating a dielectric layer thereon thereby constituting a wiring layer in the dielectric layer.
The second method involves forming a photoresist pattern on the dielectric layer, then forming a wiring groove (trench) in the dielectric layer by etching using the resist pattern as the mask, removing the resist pattern, embedding a conductive material in the wiring groove and laminating a dielectric layer thereon thereby forming a semiconductor wiring structure.
When the wiring structure is multi-layered, the step of forming a wiring layer in each method is repeatedly carried out to laminate a plurality of wiring layers, and a step of forming a via wire is necessary between the steps of forming wiring layers. The step of forming the via wire is a step which involves forming a via hole in a dielectric layer serving as an interlaminar insulating layer between lower and upper wiring layers, and depositing a conductive material into the via hole by a gaseous phase process or embedding a conductive material therein thereby forming a via wire connecting the lower wiring layer electrically to the upper wiring layer.
In either of the two wiring methods, there arises the phenomenon that upon patterning by exposing the photosensitive layer to light, the exposure light penetrates the resist layer, the penetrating light is reflected by the surface of the undercoating layer, and the reflected light enters a portion which should not be exposed to light. Such an entrance of the reflected light into the photoresist layer results in deterioration of the patterning resolution of the photoresist. In the conventional method, therefore, a resin composition containing a material absorbing exposure light is applied onto a semiconductor substrate to form an undercoating layer before formation of a photoresist layer on the substrate, and then a photoresist layer is formed on the undercoating layer. The undercoating layer is also referred to as an anti reflective coating film from the viewpoint of its action.
As the material of the anti reflective coating film, various materials have been proposed. For example, a resin composition including a polymer having an iminosulfonate group and a solvent is proposed as described in Japanese Patent Application Laid-open No. H10-319601.
As described in Japanese Patent Application Laid-open No. 2000-512336, a light-absorbing polymer including a polymer having a hydroxystyrene unit that has a specific substituent group including a sulfonate is developed, and as described in Japanese Patent Application Laid-Open No. 2000-512402, an anti reflective coating film material including the light absorbing polymer and a solvent is proposed.
In addition to the major property of anti-reflection, the undercoating layer for preventing reflection of exposure light is required to be removable by any method after the etching treatment of the lower conductive layer or the dielectric layer using the photoresist pattern as the mask.
Discussing the conventional undercoating layer from the viewpoint of removal of the undercoating layer after used as an anti reflective coating film, the anti reflective coating film material disclosed in the Japanese Patent Application Laid-open No. H10-319601 uses a polymer having an iminosulfonate group as a resin component, and the resin component is insoluble in a stripping solution for photoresist. In the techniques disclosed in the Japanese Patent Application Laid-open No. H10-319601, therefore, an upper photoresist pattern is removed with the stripping solution, and then the remaining undercoating layer is removed by O2 plasma ashing.
The resin components disclosed in the Japanese Patent Application Laid-open Nos. 2000-512336 and 2000-512402 are also insoluble in the stripping solution for photoresist so that after a photoresist pattern is removed with the stripping solution, the remaining undercoating layer is removed by O2 plasma ashing.
As is well known, in the semiconductor wiring structure, a dielectric layer with which wiring layers are covered and thereby electrically separated from other wiring layers is required to have a dielectric constant as low as possible so as not to influence the electric characteristics of the wiring layers. Specifically, the dielectric constant (k) of the dielectric material is as low as 3.0 or less in majority of cases. However, a material having such low dielectric constant is poor in resistance to O2 plasma ashing so that by exposure to O2 plasma, its surface is easily deteriorated, or the dielectric constant is increased.
When the conventional anti reflective coating film is formed on a semiconductor substrate having the dielectric layer of such low dielectric constant, O2 plasma ashing for removing the anti reflective coating layer may cause deterioration such as corrosion of the dielectric layer or rise in the electric constant, and as a result, there arises a problem that the electric characteristics of the wiring layer are adversely affected.
In production of the semiconductor wiring structure, the patterning of the photoresist and the undercoating layer by lithography is carried out for forming the wiring layer on the semiconductor by etching or for forming the wiring groove for embedding the wiring layer, as described above. The regulatory factor in the lithographic step includes many factors such as regulation of current intensity and voltage in a stepper for generating exposure light, adjustment of a focal point of a lens, accuracy of a photomask, accuracy of an attachment position, and coating properties and curing characteristics of a photoresist composition. When these regulatory factors vary for some reason, there occurs patterning insufficiency, due to which the lithographic step has to be conducted again. In this case, disposal of the semiconductor substrate and use of a new semiconductor substrate lead to waste of resources and exert an adverse effect on the environment. In the production process, it is thus required to recover the semiconductor substrate by removing the photoresist layer and undercoating layer that have been subjected to insufficient lithography. Removal of the undercoating layer in a recovering step for re-generating the semiconductor substrate is referred to as rework treatment, which is an important process in terms of economical efficiency in the production of the semiconductor wiring structure. Discussing the conventional anti reflective coating film from the viewpoint of such rework treatment, the conventional anti reflective coating layer is not suitable because there is a problem that it should be removed by O2 plasma ashing easily causing deterioration in the characteristics of a semiconductor substrate after rework treatment.
On the other hand, high integration is an everlasting task for a device having the wiring structure described above, and there is demand for finer wiring. For achieving finer wiring, it is necessary to improve the patterning resolution of the photoresist for lithography and to improve the patterning resolution of the wiring layer or the wiring groove formed by etching using a resist-pattern as the mask that has been obtained by exposure. As the thickness of the resist layer becomes thinner, the accuracy of pattern transfer to the resist using the exposure device and the wiring pattern mask can be improved. On the other hand, such a thin resist layer results in difficulty in maintaining the resistance of the resist layer in the step of etching the undercoating layer using the resist pattern as the mask, and disadvantageous effect in the etching resolution of the wiring layer or the wiring groove. To improve resist resistance, thicker layer is preferable. Therefore, there is an antinomic requirement in the determination of the photoresist thickness for improving the accuracy of lithography with a photoresist. As a technique for solving the problem to improve the accuracy of lithography with the photoresist, there is provided a wire formation method using a silicon bilayer resist and a wire formation method using a multilayer resist (Japanese Patent Application Laid-open No. H10-92740).
The former wire formation method is a lithographic technique for improving pattern transfer accuracy in spite of a thick resist layer by forming a resist not into a monolayer structure but into a two-layer structure. In this technique, a thick undercoating layer consisting of an organic polymer material is formed on a substrate, and an upper thin resist layer consisting of a silicon-containing photoresist material highly resistant to oxygen plasma etching is formed thereon. Thereafter, a wiring pattern is transferred to the upper resist layer to form an upper resist pattern. The undercoating layer is then patterned by oxygen plasma etching using the resulting upper resist pattern as a mask. The resist layer thus obtained is a layer that is thick as a whole with high pattern transfer accuracy.
Materials for constituting the silicon bilayer resist are, for example, disclosed in Japanese Patent Application Laid-open No. 2002-033257. In this application, the undercoating layer is referred to as a first resist layer, and the upper resist layer is called a second resist layer.
It is described therein that, as a general material constituting the first resist layer, a condensed polymer compound such as novolak resin, phenol resin and cresol resin and a vinyl polymer having an aromatic ring such as a phenyl group or a condensed aromatic ring such as naphthyl group or anthryl group in its side chain is used, and that various kinds of known photoresists can also be preferably used.
It is described therein that, as the silicon-containing photosensitive composition used in the second resist layer, a known one can be used.
In the silicon bilayer resist process, it is necessary to remove the resist by any method after finishing etching of the deeper conductive layer or dielectric layer using the resist pattern as the mask. In Japanese Patent Application Laid-open No. 2002-033257, a silicon-containing upper resist layer is removed by wet stripping treatment unique to this patent application, and the remaining undercoating layer is removed by O2 plasma ashing.
It is well-known that in the semiconductor wiring structure, a dielectric layer with which wiring layers are covered and thereby electrically separated from other wiring layers is required to have a dielectric constant as low as possible so as not to influence the electric characteristics of the wiring layers. Specifically, the dielectric constant (k) of the dielectric material is as low as 3.0 or less in majority of cases. However, a material having such low dielectric constant is poor in resistance to O2 plasma ashing so that by exposure to O2 plasma, its surface is easily deteriorated, or the dielectric constant is increased.
When a resist pattern made of the conventional silicon bilayer resist is formed on a semiconductor substrate having the dielectric layer of such low dielectric constant to form a wiring layer, O2 plasma ashing for removing the undercoating layer on the substrate may cause deterioration such as corrosion of the dielectric layer or rise in the electric constant, and as a result, there arises a problem that the electric characteristics of the wiring layer are adversely affected.
In production of the semiconductor wiring structure, the patterning of the photoresist and the undercoating layer by lithography is carried out for forming the wiring layer on the semiconductor by etching or for forming the wiring groove for embedding the wiring layer, as described above. The regulatory factor in the lithographic step includes many factors such as regulation of current intensity and voltage in a stepper for generating exposure light, adjustment of a focal point of a lens, accuracy of a photomask, accuracy of an attachment position, and coating properties and curing characteristics of a photoresist composition. When these regulatory factors vary for some reason, there occurs patterning insufficiency, due to which the lithographic step has to be conducted again. In this case, disposal of the semiconductor substrate and use of a new semiconductor substrate lead to waste of resources and exert an adverse effect on the environment. In this production process, it is thus required to recover the semiconductor substrate by removing the photoresist layer and undercoating layer that have been subjected to insufficient lithography. Removal of the undercoating layer in the recovering step for re-generating the semiconductor substrate is referred to as rework treatment, which is an important process in terms of economical efficiency in the production of the semiconductor wiring structure. Discussing the conventional undercoating layer from the viewpoint of such rework treatment, the conventional undercoating layer is not suitable because there is a problem that it should be removed by O2 plasma ashing easily causing deterioration in the characteristics of a semiconductor substrate after rework treatment.
As the technique of making a photoresist layer into a substantially two-layer structure, a technique of arranging, below the resist layer, an undercoating layer for the purpose of preventing exposure light from being reflected is known besides the technique of using the silicon bilayer resist. The undercoating layer is composed of a resin composition having a high ability to absorb the exposure light, and plays a role in preventing reflection of exposure light by absorbing patterning light for the upper resist thereby preventing the light from reaching the surface of the substrate. It may be considered that the material for forming the undercoating layer can also be used to form an undercoating layer in the silicon bilayer resist. If the anti reflective coating film can be removed without using O2 plasma ashing, the problem in the wiring formation method using the silicon bilayer resist can be solved.
As a material for the ant reflective coating film, various compositions have been proposed. For example, a resin composition containing a polymer having an iminosulfonate group and a solvent is proposed (Japanese Patent Application Laid-open No. H10-319601).
A light-absorbing polymer containing a polymer having a hydroxystyrene unit that has a specific substituent group containing a sulfonate has been developed, (Japanese Patent Application Laid-open No. 2000-512336) and a anti reflective coating film material including the light absorbing polymer and a solvent has been proposed (Japanese Patent Application Laid-open No. 2000-512402).
The anti reflective coating film material disclosed in the Japanese Patent Application Laid-open No. H10-319601 uses a polymer having an iminosulfonate group as a resin component, and the resin component is insoluble in a stripping solution for photoresist. In the techniques disclosed in the Japanese Patent Application Laid-open No. H10-319601, therefore, the upper photoresist pattern is removed with the stripping solution, and then the remaining undercoating layer is removed by O2 plasma ashing.
The resin components disclosed in the Japanese Patent Application Laid-open Nos. 2000-512336 and 2000-512402 are also insoluble in the stripping solution for photoresist, and after the photoresist pattern is removed with the stripping solution, the remaining undercoating layer is removed by O2 plasma ashing.
Accordingly, even if the conventional anti reflective coating film is employed as the undercoating layer in the silicon bilayer resist, the problem attributable to removal of the undercoating layer cannot be solved.
The latter of the aforementioned wiring formation methods (Japanese Patent Application Laid-open No. H10-92740) or the multilayer process is the technique of forming the resist not into the single layer but into the multilayer structure, whereby (1) the uppermost photoresist layer to which the pattern is first transferred through the mask is made thin to improve both resolution and focal depth in lithography and (2) the anti reflective coating film etc. having less film interfering effect and high resistance to etching is formed as a multilayer below the uppermost layer, to give a resist pattern excellent in dry etching resistance with high pattern transfer accuracy. In this technique, a composite anti reflective coating film is first formed on a substrate. This composite anti reflective coating film is a multilayer composed for example of a carbon film and a silicon oxide film and if necessary a silicon nitride barrier layer therebetween. An upper thin photoresist layer is formed on the multilayer. Thereafter, a wiring pattern is transferred by lithography to the upper photoresist layer, to form an upper resist pattern. The silicon oxide film as an intermediate layer is then subjected to etching with the resulting upper resist pattern as the mask to transfer the pattern. Subsequently, the carbon film as an undercoating layer is subjected to etching using the upper resist pattern and the intermediate layer pattern as the mask, to transfer the wiring pattern. Finally, the upper resist pattern and the intermediate layer pattern are removed, whereby a carbon film (undercoating layer) pattern excellent in dry etching resistance with high pattern transfer accuracy is obtained. The substrate is etched according to the pattern with the undercoating layer pattern as the mask.
In the multilayer resist, it is necessary to remove the finally remaining undercoating layer (carbon film) pattern by any method after finishing patterning by etching processing of the lower conductive layer or dielectric layer. In Japanese Patent Application Laid-open No. H10-92740, the pattern is removed by O2 plasma ashing.
It is well-known that in the semiconductor wiring structure, a dielectric layer with which wiring layers are covered and thereby electrically separated from other wiring layers is required to have a dielectric constant as low as possible so as not to influence the electric characteristics of the wiring layers. Specifically, the dielectric constant (k) of the dielectric material is required to be as low as 3.0 or less. However, a material having such low dielectric constant is poor in resistance to O2 plasma ashing so that by exposure to O2 plasma, its surface is easily deteriorated, or the dielectric constant is increased.
When a resist pattern made of the conventional multilayer resist is formed on a semiconductor substrate having the dielectric layer of such low dielectric constant to form a wiring layer, O2 plasma ashing for removing the undercoating layer on the substrate may cause deterioration such as corrosion of the dielectric layer or rise in the electric constant, and as a result, there arises a problem that the electric characteristics of the wiring layer are adversely affected.
In production of the semiconductor wiring structure, the patterning of the photoresist and the undercoating layer by lithography is carried out for forming the wiring layer on the semiconductor by etching or for forming the wiring groove for embedding the wiring layer, as described above. The regulatory factor in the lithographic step includes many factors such as regulation of current intensity and voltage in a stepper for generating exposure light, adjustment of a focal point of a lens, accuracy of a photomask, accuracy of an attachment position, and coating properties and curing characteristics of a photoresist composition. When these regulatory factors are varied for some reason, there occurs patterning insufficiency, due to which the lithographic step has to be conducted again. In this case, disposal of the semiconductor substrate and use of a new semiconductor substrate lead to waste of resources, and exert an adverse effect on the environment. When insufficiency in lithography is found out in such a production process, it is therefore necessary to recover the semiconductor substrate by removing the resist remaining on the substrate. Removal of the defective resist in the recovering step for re-generating the semiconductor substrate is referred to as rework treatment, which is an important process in terms of economical efficiency in the production of the semiconductor wiring structure. Discussing the conventional undercoating layer from the viewpoint of such rework treatment, the conventional undercoating layer is not suitable because there is a problem that it should be removed by O2 plasma ashing easily causing deterioration in the characteristics of a semiconductor substrate after rework treatment.
A phenomenon called poisoning that often occurs upon use of a low-dielectric layer as an interlaminar insulating layer for supporting the wiring layer is recently problematic in the step of forming a resist pattern, and there is a need for solving it.
The poisoning phenomenon occurs easily upon use of the low-dielectric layer as the interlaminar insulating layer, and cannot be prevented by the conventional undercoating material. Accordingly, there is demand at present for development of an undercoating material capable of maintaining easiness of removal after use and of preventing the poisoning phenomenon in the wiring structure forming process using the low-dielectric layer.
As the technique of making a photoresist layer into a substantially multilayer (two-layer) structure, a technique of arranging, below the resist layer, an undercoating layer for the purpose of preventing exposure light from being reflected is known besides the technique of using the multilayer resist. The undercoating layer is composed of a resin composition having a high ability to absorb the exposure light, and plays a role in preventing reflection of exposure light by absorbing patterning light for the upper resist thereby preventing the light from reaching the surface of the substrate. If the anti reflective coating film can be removed without using O2 plasma ashing, and can prevent the adverse influence of poisoning on the resist layer, the problem in the wiring formation method using the multilayer resist can be solved.
As a material for the anti reflective coating film, various materials have been proposed. For example, a resin composition containing a polymer having an iminosulfonate group and a solvent is proposed. (Japanese Patent Application Laid-open No. H10-319601)
A light-absorbing polymer containing a polymer having a hydroxystyrene unit that has a specific substituent group containing a sulfonate has been developed, (Japanese Patent Application Laid-open No. H2000-512336) and an anti reflective coating film material including the light absorbing polymer and a solvent has been proposed. (Japanese Patent Application Laid-open No. H2000-512402)
The anti reflective coating film material disclosed in the Japanese Patent Application Laid-open No. H10-319601 uses a polymer having an iminosulfonate group as a resin component, and the resin component is insoluble in a stripping solution for photoresist. In the techniques disclosed in the Japanese Patent Application Laid-open No. H10-319601, therefore, the upper photoresist pattern is removed with the stripping solution, and then the remaining undercoating layer is removed by O2 plasma ashing.
The resin components disclosed in the Japanese Patent Application Laid-open Nos. 2000-512336 and 2000-512402 are also insoluble in the stripping solution for photoresist so that after the photoresist pattern is removed with the stripping solution, the remaining undercoating layer is removed by O2 plasma ashing.
Accordingly, even if the conventional anti-reflective coating film is employed as the undercoating layer in the multilayer resist, the problem attributable to removal of the undercoating layer cannot be solved.
In light of a fundamental wiring structure in a semiconductor integrated circuit, it is well-known that the fundamental wiring structure is a structure wherein a lower wiring layer formed directly or indirectly on a semiconductor substrate and an upper wiring layer formed via an interlaminar insulating layer on the lower wiring layer are connected through a via wire formed so as to penetrate the interlaminar insulating layer. By combining a plurality of such wiring structures, the multilayer wiring structure of a semiconductor integrated circuit is formed.
As a method of realizing the multilayer wiring structure by using copper excellent in electro-migration resistance, a dual damascene process is known. In the dual damascene process, a dual damascene structure composed at least of a first etching space formed in a low-dielectric layer on a substrate and a second etching space communicating with the first etching space and different in shape and dimension to those of the first etching space is formed. The above-described wiring structure is realized by embedding a conductive material in the dual damascene structure.
The fundamental dual damascene process is described in more detail by reference to FIGS. 1A to 1D and FIGS. 2E to 2H.
As illustrated in FIG. 1A, an interlaminar insulating layer 2 is formed on substrate 1. SiO2, carbon doped oxide (SiON), spin-on-glass (hereinafter, "SOG") or the like are used as a material for forming the interlaminar insulating layer 2. A resist layer 3 is formed and patterned on the interlaminar insulating layer 2. The interlaminar insulating layer 2 is etched selectively with the patterned resist layer 3 as the mask, and then the resist layer 3 is removed, whereby a wiring groove (trench) 4 is formed as illustrated in FIG. 1B. A barrier metal 5 is then deposited on the surface of the interlaminar insulating layer 2 having the wiring groove 4 formed therein as described above, whereby the adhesion between copper to be embedded in the wiring groove 4 and the interlaminar insulating layer 2 is improved while a barrier metal film for preventing diffusion of copper into the interlaminar insulating layer 2 is formed on the wiring groove 4. As illustrated in FIG. 1C, copper is then embedded in the wiring groove 4 by electrolytic plating etc., to form a lower wiring layer 6.
Copper adhering to the surface of the interlaminar insulating layer 2, and the remaining barrier metal 5, are then removed by chemical polishing (hereinafter, "CMP"), to flatten the surface of the interlaminar insulating layer 2, and then a first low-dielectric layer 7, a first etching stopper film 8, a second low-dielectric layer 9 and a second etching stopper film 10 are laminated thereon in this order. A resist mask 11 having a pattern for forming a via hole is then formed on the second etching stopper film 10. As illustrated in FIG. 1D, the resist mask 11 is used in etching, whereby a via hole 12 penetrating the second etching stopper film 10, the second low-dielectric body 9, the first etching stopper layer 8 and the first low-dielectric layer 7 and reaching the surface of the lower wiring layer 6 is formed. As illustrated in FIG. 2E, embedded material 13 such as a photoresist material is then charged into the via hole 12. The embedded material 13 is etched back so that as illustrated in FIG. 2F, the material 13 having a desired thickness was left in the bottom of the via hole 12, and a resist mask 14 having a trench-forming pattern is formed on the second etching stopper film 10. As illustrated in 2G, the second etching stopper film 10 and the second low-dielectric layer 9 are etched using the resist mask 14, whereby a trench 15 is formed and simultaneously the embedded material 13 remaining at the bottom of the via hole 12 is removed. Thereafter, copper is embedded in the via hole 12 and the trench 15, to form a via wire 16 and upper wiring layer 17, as illustrated in FIG. 2H. A multilayer wiring structure having the lower layer wiring layer 6 connected electrically through the via wire 16 to the upper wiring layer 17 is thus realized.
In the multilayer wiring structure obtained by the process, the trench corresponds to the first etching space or the second etching space, and the via hole corresponds to the second etching space or the first etching space. In the process illustrated in FIG. 1, therefore, the dual damascene structure is constituted by the trench 15 and the via hole 12 connected to the bottom of the trench 15.
In the method of forming the dual damascene structure, an embedded material is used. The role of the embedded material is as follows. That is, upon etching for forming the trench after forming the via hole, existence of a exposed portion of the substrate at the bottom of the via hole may cause damage on the lower wiring layer on the substrate by the etching gas for forming the trench, which may result in defects in wiring. The embedded material is thus charged into the via hole to protect the lower wiring layer in the trench formation step.
As the embedded material, a photoresist composition is conventionally used. However, when such a photoresist composition is charged into the via hole, the composition may form bubbles to cause defect in embedding. It is therefore proposed to use, as a new filler material, a solution having a heat-crosslinking compound dissolved in an organic solvent. (Japanese Patent Application Laid-open No. 2002-033257)
In the constitution using the organic film as an filler material, there is however a problem that removal of the embedded material remaining in the via hole is not easy after use, thus requiring its removal by oxygen plasma ashing. In this case, the low-dielectric layer may be damaged by an ashing gas (mainly an oxygen-based gas). The damage includes a change of Si—R bond into Si—OH bond or an increase in dielectric constant (k) in the low-dielectric layer.
A photoresist is used in forming a wiring layer, and exposed to light in patterning, but there is a known problem that the exposure light is reflected by the surface of the undercoating layer, and the reflected light enters a non-light-exposed region, to reduce the patterning resolution of the resist. A technique of arranging, below the resist layer, an undercoating layer for the purpose of preventing exposure light from being reflected is known, and the undercoating layer is composed of a resin composition having a high ability to absorb the exposure light, and plays a role in preventing reflection of exposure light by absorbing patterning light for the upper resist thereby preventing the light from reaching the surface of the undercoating layer. It may be considered that the material for forming the lower anti reflective coating film can also be used as a n embedded material for forming the dual damascene structure. If the anti reflective coating film can be removed without using O2 plasma ashing, the problem in the dual damascene structure formation method can be solved.
As a material for the anti reflective coating film, various materials have been proposed. For example, a resin composition containing a polymer having an iminosulfonate group and a solvent is proposed. (Japanese Patent Application Laid-open No. H10-319601)
A light-absorbing polymer containing a polymer having a hydroxystyrene unit that has a specific substituent group containing a sulfonate has been developed, (Japanese Patent Application Laid-open No. 2000-512336) and an anti reflective coating film material including the light absorbing polymer and a solvent has been proposed. (Japanese Patent Application Laid-open No. 2000-512402)
The anti reflective coating film material disclosed in the Japanese Patent Application Laid-open No. H10-319601 uses a polymer having an iminosulfonate group as a resin component, and the resin component is insoluble in a stripping solution for photoresist. In the techniques disclosed in the Japanese Patent Application Laid-open No. H10-319601, therefore, the upper photoresist pattern is removed with the stripping solution, and then the remaining undercoating layer is removed by O2 plasma ashing.
The resin components disclosed in the Japanese Patent Application Laid-open Nos. 2000-512336 and 2000-512402 are also insoluble in the stripping solution for photoresist so that after the photoresist pattern is removed with the stripping solution, the remaining undercoating layer is removed by O2 plasma ashing.
Accordingly, even if the conventional anti reflective coating film is employed as the embedded material for forming a dual damascene structure, the problem attributable to removal of the embedded material cannot be solved.
On the other hand, use of a spin-on-glass material as the filler material for forming a dual damascene structure is conceivable. Use of the spin-on-glass material as the filler material is disclosed in for example U.S. Pat. No. 6,329,118. The spin-on-glass material can be removed with a stripping solution, and thus the remaining embedded material can be removed without using O2 plasma ashing, and the problem of deterioration in the low-dielectric layer can be eliminated.
However, a phenomenon called poisoning that often occurs upon use of the low dielectric layer as the interlaminar insulating layer for supporting the wiring layer is recently problematic in the step of forming the dual damascene structure, and this problem also occurs even upon use of the spin-on-glass material as the filler material or the filler material removable by O2 plasma ashing, and there is a need for solving it.
The above-described poisoning causes a significant defect in the shape of the second etching space 15 obtained in the wiring formation process illustrated in FIG. 2G. FIG. 3 is a schematic view showing a normal etching space and an etching space having defect in shape. FIG. 3A is an enlarged plan view of an essential part where the trench (second etching space) 15 can be formed normally without the poisoning phenomenon, and 3B is an enlarged plan view of an essential part where the poisoning phenomenon occurred to cause defects in the shape of the trench (second etching space) 15. In FIG. 3, the same element as in FIGS. 1 and 2 is given the same symbol to simplify the description. FIG. 3B is illustrated with relatively higher magnification than FIG. 3A. As illustrated in the figures, the embedded material and the photoresist layer are deteriorated by the poisoning phenomenon due to a basic substance generated from the low-dielectric layer 9, and the resist pattern is formed such that the via hole (first etching space) 12 is covered therewith, and the shape of the trench 15 is significantly deformed.
The above-described poisoning phenomenon occurs easily upon use of the low dielectric layer as the interlaminar insulating layer, and cannot be prevented by the conventional filler material for forming the dual damascene structure. Accordingly, there is demand at present for development of the filler material capable of preventing the poisoning phenomenon while maintaining a property of entering into the etching space and easiness of removal after use in the process for forming a dual damascene structure using a low-dielectric layer.

Undercoating material for wiring, embedded material, and wiring formation method

Abstract: wherein n is an integer of 1 or more, X represents a C1 to C10 linear or branched alkyl chain, an aromatic or alicyclic alkyl chain or an alkyl ester chain, and Y is a substituent group forming a sulfonic acid residue upon application of predetermined energy.


In a multi-piece solid golf ball comprising a solid core, a mantle and a cover, the solid core is made of a rubber composition that includes a base rubber containing a polybutadiene synthesized using a rare-earth catalyst, a small amount of organic peroxide, an unsaturated carboxylic acid and/or a metal salt thereof, an organic sulfur compound and an inorganic filler. The mantle is made of a thermoplastic resin composition. The cover is made primarily of a thermoplastic polyurethane material. This construction provides the golf ball with a combination of outstanding flight performance and soft feel with cover's scuff resistance and coating's abrasion resistance, that is unprecedented.

1. Field of the Invention
The present invention relates to golf balls which have an outstanding flight performance, a soft "feel" upon impact, cover's scuff resistance and paint coating's abrasion resistance.
2. Prior Art
Golf balls of varying structures are known in the art. A number of proposals have been made on solid golf balls, especially multi-piece solid golf balls having a solid core enclosed with a plurality of cover layers in order to further improve their carry, controllability (spin rate) and feel. The present assignee, among others, has already disclosed many outstanding golf balls.
For example, JP-A 9-215775 describes a multi-piece solid golf ball which is improved in carry, controllability, straight run and rolling on the green, and cover durability by optimizing the inertia moment of the ball in accordance with the hardness of the cover outermost layer, and optimizing dimple parameters.
JP-A 10-151225 discloses a golf ball having a solid core, a mantle and a cover, in which the specific gravity of solid core is less than those of mantle and cover, the Shore D hardness of mantle is higher than that of cover, and the inertia moment of the overall ball is set at 83 g-cm2 or greater, whereby the golf ball is endowed with a soft feel and a satisfactory spin receptivity for a particular type of club, without detracting from carry and durability, that is, the golf ball having the advantages of carry, durability, feel and spin controllability.
JP-A 10-151226 discloses a golf ball having a solid core, a mantle and a cover, in which the solid core has a deflection of at least 2.5 mm under a load of 100 kgf, the Shore D hardness of mantle is at least 13 units higher than that of cover, and the inertia moment of the overall ball is set at 83 g-cm2 or greater, whereby the golf ball is endowed with a soft feel and a satisfactory spin receptivity for a particular type of club, without detracting from carry and durability, that is, the golf ball having the advantages of carry, durability, feel and spin controllability.
JP-A 11-104273 discloses a golf ball having a solid core, a cover inner layer and a cover outer layer, in which the solid core has a deflection of at least 2.4 mm under a load of 100 kgf, the cover inner layer is formed primarily of an ionomer resin to a Shore D hardness of 28-58, the cover outer layer is formed primarily of a thermoplastic polyurethane elastomer to a Shore D hardness of 30-55, whereby the golf ball has an increased carry, controllability on iron shots, a good feel when hit with any of wood, iron and putter clubs, resistance to burring on control shots with an iron club, and durability.
JP-A 2001-54588 describes a golf ball having a solid core, a cover inner layer and a cover outer layer, in which the solid core has a deflection of at least 1.1 mm under a load of 30 kgf, the cover inner layer has a Shore D hardness of 45-61, the cover outer layer has a Shore D hardness of 35-55, the sum of dimple trajectory volumes obtained by multiplying a dimple volume by the square root of a dimple diameter is in a range of 530-750, whereby the golf ball features an elongated flight performance with a relatively low trajectory, an increased carry, controllability on iron shots, a good feel when hit with any of wood, iron and putter clubs, resistance to burring on control shots with an iron club, and durability.
JP-A 2002-85587, 2002-85588 and 2002-85589 disclose golf balls featuring an excellent flight performance, good spin characteristics, a good feel when hit with any of wood, iron and putter clubs, resistance to burring on control shots with an iron club, and durability.
These prior-art golf balls all have an excellent feel and an excellent carry and other flight characteristics, and can be suitably adapted to various requirements dictated by the skill level of the golfer and the intended use of the ball (e.g., recreational or competitive). Yet, given the ever-high expectations of golfers, there exists a need for golf balls endowed with an even better performance.


A translation lookaside buffer (TLB) of a computing device is a cache of virtual to physical memory address translations. A TLB flush promotion threshold value indicates when all entries of the TLB are to be flushed rather than individual entries of the TLB. The TLB flush promotion threshold value is determined dynamically by the computing device by determining an amount of time it takes to flush and repopulate all entries of the TLB. A determination is then made as to the number of TLB entries that can be individually flushed and repopulated in that same amount of time. The threshold value is set based on (e.g., equal to) the number of TLB entries that can be individually flushed and repopulated in that amount of time.

Many computer processors support virtual memory, which is a mechanism that allows different programs to share physical memory. A memory manager assigns a virtual memory space to each program and each program operates with reference to its assigned virtual memory space. The memory manager controls translating memory addresses in the virtual memory space to memory addresses in the shared physical memory. One component used by the memory manager is a translation lookaside buffer, which caches memory address translations. Situations can arise in which at least a portion of the translation lookaside buffer is to be flushed. However, it can be difficult to determine whether the entire translation lookaside buffer is to be flushed or only particular entries of the translation lookaside buffer are to be flushed, which can result in reduced performance of the processor.

Dynamically determining a translation lookaside buffer flush promotion threshold value