Abstract: An abrasive disc comprises a disc substrate having a peripheral portion, plural abrasive chips each having an abrasive layer on a metal piece and being arranged in the peripheral portion of the disc substrate with a predetermined space, a suspension plate placed between the disc substrate and abrasive chips, and an elastic sheet placed between the disc substrate and the suspension plate so as to isolate the disc substrate from the suspension plate in order to absorb mechanical shock generated in operation of the abrasive disc. The abrasive chips are fastened to the suspension plate. Each of the abrasive chips has abrasive surfaces including a top abrasive surface and peripheral surfaces and the outer peripheral portion and the inner peripheral portion are declined to the top surface.

Abstract: An abrasive disc which has plural abrasive chips having an abrasive layer on a metal piece and being arranged in a peripheral portion of a disc substrate with a predetermined space comprises a suspension plate placed between the disc substrate and abrasive chips and an elastic sheet placed between the disc substrate and the suspension plate, wherein the disc substrate consists of a plastic resin including fiber, the abrasive chips have stakes therein and the suspension plate has through-holes to which the stakes are deformed therein. Each of the abrasive chips has abrasive surfaces including a top abrasive surface and peripheral surfaces and the outer peripheral portion and the inner peripheral portion are declined to the top surface. The abrasive discs have a combination of different abrasive chips fabricated by different bonding metals for the fabrication of the abrasive chips.

Abstract: A pattern can be written in accordance with a distortion which changes depending upon exposure conditions of the optical exposure system and exposed pattern features, and a pattern can be written with a high alignment accuracy by the optical exposure system and an electron beam lithography system or two optical exposure systems. A pattern which is exposed by optical exposure system divided into very small areas shown by broken lines, and pattern feature amounts (fx), (fy) at each area are calculated. A correction amount is obtained by using the pattern feature amount and the position within an exposure field as parameters based on exposure distortion examined by a standard pattern predeterminedly.

Abstract: An electron beam writing apparatus comprises: an electron beam source for projecting an electron beam; a first mask provided with a first rectangular aperture for passing the electron beam projected by the electron beam source to shape the electron beam in a primary shaped beam having a rectangular cross section; a second mask provided with a second rectangular aperture for passing the primary shaped beam to shape the primary shaped beam in a secondary shaped beam having a rectangular cross section, and triangular apertures for passing the primary shaped beam to form a secondary shaped beam having a triangular cross section; a first electron beam deflecting system for moving the primary shaped beam on the surface of the second mask; and a second electron beam deflecting system for moving the secondary shaped beam on the surface of a workpiece on which a pattern is to be written.

Abstract: An electron beam lithography system which generates phase shift pattern data relating to main patterns, and exposes the phase shift pattern on a mask plate by using an electron beam in accordance with instruction from a computer. An electron beam lithography system is provided which can remarkably decrease a time needed for preparing phase shift pattern data. The apparatus is furnished with a parameter table for storing equations to generate phase shift pattern data, and generates the phase shift pattern data by assigning original pattern data into equations in accordance with a corresponding instruction for applying a phase shift method, and automatically exposes the phase shift pattern.

Abstract: A lithographic method and a lithographic apparatus ar disclosed in which the height of a silicon wafer making up an object of lithography is accurately measured. A lithographic apparatus such as an electron beam apparatus having a height-measuring instrument built therein is effectively used for forming a pattern on the order of submicrons.

Abstract: An electron beam lithograhy apparatus capable of uniformly exposing the surface of a sample by an electron beam including a generator for generating the electron beam, members for shaping the electron beam, members for focusing the shaped electron beam on the surface of the sample, devices for permitting the focused electron beam to scan the surface of the sample, and devices for deflecting the electron beam to blank, unblank and blank in turn, wherein when the electrom beam is deflected in one direction, a sequence of blanking, unblanking and blanking is made of the beam.

Abstract: A ring grinding tool suitable for use in grinding or polishing a workpiece, particularly having a curvature, is provided. The tool comprises at least one rubber-made supporting layer reinforced with a metal wire and having a surface adapted for mating and contacting a rotary wheel, at least one porous elastic layer provided on the supporting layer, at least one elastic protective layer made of a rubber sheet provided on the porous elastic layer and a plurality of flat abrasive pieces provided on the elastic protective layer.

Abstract: A charged particle beam apparatus in which a beam of charged particles emitted from a beam source is focussed on a target in a predetermined size and shape through a plurality of aperture members. Each of the aperture members is combined with a respective deflecting unit which effects a two-dimensional scan with the charged particle beam in response to a scan signal supplied thereto. The center axis of the aperture formed in the aperture member is arithmetically determined on the basis of time-based variation in the quantity of the charged particles trapped by the aperture member during the scan operation. Further, deviation of the arithmetically determined center axis of the aperture from a reference axis is determined. The aperture member is slided on a plane extending perpendicularly to the center axis of the aperture to cancel out the deviation.