Abstract: The invention provides a polishing pad by which optical materials such as lenses, reflecting mirrors etc., or materials requiring a high degree of surface planarity, as in the polishing of silicone wafers, glass substrates or aluminum substrates for hard disks, or general metal polishing, can be flattened with stability and high polishing efficiency. The invention also provides a polishing pad for semiconductor wafers, which is superior in planarizing characteristic, is free from scratches and can be produced at low cost. There is provided a polishing pad which is free from dechucking error so that neither damage to wafers nor decrease in operating efficiency occurs. There is provided a polishing pad which is satisfactory in planarity, within wafer uniformity, and polishing rate and produces less change in polishing rate. There is provided a polishing pad which can make planarity improvement and scratch decrease compatible.

Abstract: A polishing pad includes a polishing layer having abrasive grains dispersed in a resin and is characterized in that the resin is a resin containing ionic groups in the range of 20 to 1500 eq/ton.

Abstract: The invention provides a polishing pad by which optical materials such as lenses, reflecting mirrors etc., or materials requiring a high degree of surface planarity, as in the polishing of silicone wafers, glass substrates or aluminum substrates for hard disks, or general metal polishing, can be flattened with stability and high polishing efficiency. The invention also provides a polishing pad for semiconductor wafers, which is superior in planarizing characteristic, is free from scratches and can be produced at low cost. There is provided a polishing pad which is free from dechucking error so that neither damage to wafers nor decrease in operating efficiency occurs. There is provided a polishing pad which is satisfactory in planarity, within wafer uniformity, and polishing rate and produces less change in polishing rate. There is provided a polishing pad which can make planarity improvement and scratch decrease compatible.

Abstract: A polishing pad includes at least a polishing layer and a cushion layer and is characterized in that the difference in hardness in Shore D hardness between the polishing layer and the cushion layer is 3 or more.

Abstract: The invention provides a polishing pad by which optical materials such as lenses, reflecting mirrors etc., or materials requiring a high degree of surface planarity, as in the polishing of silicone wafers, glass substrates or aluminum substrates for hard disks, or general metal polishing, can be flattened with stability and high polishing efficiency. The invention also provides a polishing pad for semiconductor wafers, which is superior in planarizing characteristic, is free from scratches and can be produced at low cost. There is provided a polishing pad which is free from dechucking error so that neither damage to wafers nor decrease in operating efficiency occurs. There is provided a polishing pad which is satisfactory in planarity, within wafer uniformity, and polishing rate and produces less change in polishing rate. There is provided a polishing pad which can make planarity improvement and scratch decrease compatible.

Abstract: A method of producing a polishing pad having a polishing layer is characterized in that the polishing layer is produced by a photolithographic method including: forming a sheet molding from a curing composition containing at least an initiator and an energy ray-reactive compound to be cured with energy rays; exposing the sheet molding to energy rays to induce modification thereof, to change the solubility of the sheet molding in a solvent; and developing the sheet molding after irradiation with energy rays, to partially remove the curing composition with a solvent thereby forming a concave and convex pattern at least one surface.

Abstract: The polishing pad of this invention is a polishing pad effecting stable planarizing processing, at high polishing rate, materials requiring surface flatness at high level, such as a silicon wafer for semiconductor devices, a magnetic disk, an optical lens etc. This invention provides a polishing pad which can be subjected to surface processing to form a sheet or grooves, is excellent in thickness accuracy, attains a high polishing rate, achieves a uniform polishing rate, and also provides a polishing pad which is free of quality variations resulting from an individual variation, easily enables a change the surface patterns, enables fine surface pattern, is compatible with various materials to be polished, is free of burrs upon forming the pattern. This invention provides a polishing pad which can have abrasive grains mixed at very high density without using slurry, and generates few scratches by preventing aggregation of abrasive grains dispersed therein.

Abstract: The invention provides a polishing pad by which optical materials such as lenses, reflecting mirrors etc., or materials requiring a high degree of surface planarity, as in the polishing of silicone wafers, glass substrates or aluminum substrates for hard disks, or general metal polishing, can be flattened with stability and high polishing efficiency. The invention also provides a polishing pad for semiconductor wafers, which is superior in planarizing characteristic, is free from scratches and can be produced at low cost. There is provided a polishing pad which is free from dechucking error so that neither damage to wafers nor decrease in operating efficiency occurs. There is provided a polishing pad which is satisfactory in planarity, within wafer uniformity, and polishing rate and produces less change in polishing rate. There is provided a polishing pad which can make planarity improvement and scratch decrease compatible.

Abstract: The invention provides a polishing pad by which optical materials such as lenses, reflecting mirrors etc., or materials requiring a high degree of surface planarity, as in the polishing of silicone wafers, glass substrates or aluminum substrates for hard disks, or general metal polishing, can be flattened with stability and high polishing efficiency. The invention also provides a polishing pad for semiconductor wafers, which is superior in planarizing characteristic, is free from scratches and can be produced at low cost. There is provided a polishing pad which is free from dechucking error so that neither damage to wafers nor decrease in operating efficiency occurs. There is provided a polishing pad which is satisfactory in planarity, within wafer uniformity, and polishing rate and produces less change in polishing rate. There is provided a polishing pad which can make planarity improvement and scratch decrease compatible.

Abstract: A method of producing a polishing pad having a polishing layer is characterized in that the polishing layer is produced by a photolithographic method including: forming a sheet molding from a curing composition containing at least an initiator and an energy ray-reactive compound to be cured with energy rays; exposing the sheet molding to energy rays to induce modification thereof, to change the solubility of the sheet molding in a solvent; and developing the sheet molding after irradiation with energy rays, to partially remove the curing composition with a solvent thereby forming a concave and convex pattern at least one surface.

Abstract: A polishing pad includes at least a polishing layer and a cushion layer and is characterized in that the difference in hardness in Shore D hardness between the polishing layer and the cushion layer is 3 or more.

Abstract: A polishing pad includes a polishing layer having abrasive grains dispersed in a resin and is characterized in that the resin is a resin containing ionic groups in the range of 20 to 1500 eq/ton.

Abstract: The invention provides a polishing pad by which optical materials such as lenses, reflecting mirrors etc., or materials requiring a high degree of surface planarity, as in the polishing of silicone wafers, glass substrates or aluminum substrates for hard disks, or general metal polishing, can be flattened with stability and high polishing efficiency. The invention also provides a polishing pad for semiconductor wafers, which is superior in planarizing characteristic, is free from scratches and can be produced at low cost. There is provided a polishing pad which is free from dechucking error so that neither damage to wafers nor decrease in operating efficiency occurs. There is provided a polishing pad which is satisfactory in planarity, within wafer uniformity, and polishing rate and produces less change in polishing rate. There is provided a polishing pad which can make planarity improvement and scratch decrease compatible.

Abstract: The polishing pad of this invention is a polishing pad effecting stable planarizing processing, at high polishing rate, materials requiring surface flatness at high level, such as a silicon wafer for semiconductor devices, a magnetic disk, an optical lens etc. This invention provides a polishing pad which can be subjected to surface processing to form a sheet or grooves, is excellent in thickness accuracy, attains a high polishing rate, achieves a uniform polishing rate, and also provides a polishing pad which is free of quality variations resulting from an individual variation, easily enables a change the surface patterns, enables fine surface pattern, is compatible with various materials to be polished, is free of burrs upon forming the pattern. This invention provides a polishing pad which can have abrasive grains mixed at very high density without using slurry, and generates few scratches by preventing aggregation of abrasive grains dispersed therein.

Abstract: The present invention provides a method of extracting and isolating nucleic acids from a material containing nucleic acids using a nucleic acid-binding particulate carrier. More specifically, the present invention provides a nucleic acid extraction method using a particulate carrier having a particle diameter of 0.5 to 15.0 &mgr;m, a pore diameter of 50 to 500 nm and a pore volume of 200 to 5000 mm3/g. According to the method of the invention, nucleic acids can be efficiently extracted from a biological material, in particular a material containing a large amount of contaminants, such as a clinical sample.

Abstract: This invention provides an apparatus for extracting nucleic acids from nucleic acid-containing samples. The nucleic acid extraction apparatus of the invention comprises (1) a group of extraction vessels each comprising a reactor tube in which a sample, a reagent solution, and a magnetic carrier are admixed and reacted, a drain cup for pooling an unwanted component solution, and a nucleic acid recovery tube all as secured to a support, (2) a distribution means for introducing a solution into each of the extraction vessels, (3) a stirring means for mixing the solution and magnetic carrier in the reactor tube, (4) a holding means for holding the magnetic carrier stationary within the vessel, (5) a discharging means for discharging the solution from the reactor tube while the magnetic carrier is held stationary, (6) a heating means for heating the solution and magnetic carrier in the reactor tube, and (7) a transfer means for serially transferring the vessels to the given positions.

Abstract: This invention provides an apparatus for extracting nucleic acids from nucleic acid-containing samples, particularly biological samples, and more particularly to a nucleic acid extraction apparatus well suited for the nucleic acid extraction method utilizing a nucleic acid-binding magnetic carrier.

Abstract: Method for judging a color difference between a color of an object and a reference color and apparatus therefor in which it is judged at first if the color difference exists within a predetermined range in which it is difficult to determine whether or not the color difference is definite and, if it exists within the predetermined range, the color difference is judged whether it is substantial or nealigible according to rules according to Fuzzy inference.