Abstract: Apparatus and methods are disclosed for inscribing a pattern on a reticle blank to produce a lithography reticle. As a reticle blank is inscribed using a charged particle beam (e.g., electron beam), some of the incident charged particles pass through the reticle blank and are backscattered from underlying structure (e.g., from a stage used to hold the reticle blank during inscription). These backscattered particles reduce the pattern resolution on the reticle. The present apparatus and methods reduce the number of backscattered particles re-entering the reticle blank, thereby improving pattern resolution.

Abstract: Hollow-beam apertures and methods for using same are disclosed, especially for achieving alignment of the beam center with the center of the hollow-beam aperture. The hollow-beam apertures define beam-transmissive portions (e.g., through-holes) that form a hollow beam propagating downstream of the hollow-beam aperture. Also included is a relatively thick region that causes absorption of at least a portion of the incident beam and may also cause localized scattering of the beam. Absorption of charged particles generates an electrical current that can be measured. From such current measurements accompanying controlled displacement of the incident beam, a measurement of the lateral beam-intensity distribution can be obtained. I.e., the current typically is maximal whenever the beam center is aligned with the center of the hollow-beam aperture. Lateral beam adjustment can be achieved using an aligner (deflector assembly).

Abstract: The present invention provides CPB projection apparatus and transfer methods for transferring a pattern from a mask onto a wafer with precise linear-distortion correction of transferred images without creating significant astigmatic blur of the image. A preferred embodiment of the projection apparatus includes an illumination-optical system and a projection-optical system. The illumination-optical system includes a CPB source for emitting a charged-particle beam, and first and second condenser lenses. A field-limiting aperture limits the field of the charged-particle flux. A first astigmatic-aberration correction coil is positioned at a principal plane of either the first or second projection lens and corrects linear distortion of a resulting projected image. A third condenser lens collimates the beam to form an image of the field-limiting aperture on a selected subfield of the mask. A projection-lens system demagnifies the image formed by the mask and projects the demagnified image on a wafer.

Abstract: A charged-particle-beam pattern-transfer apparatus is provided wherein a CPB is emitted from the CPB source, is focused by first and second condenser lenses, and is illuminated onto a mask. A deflector deflects the CPB to a selected subfield of the mask. The CPB transmitted by subfield is projected by a first projection lens toward a back-focal-plane aperture. The portion of the CPB that passes through the back-focal-plane aperture is projected by a second projection lens onto a wafer. Coulomb effect induced shifts in focal-point position, and changes in image magnification, projected-image rotation, and astigmatic blur and astigmatic distortions of the image are each corrected by application of electric current supplied to each component of a correction system, the correction system preferably comprising a set of correction lenses and two stigmators.

Abstract: A charged-particle-beam pattern-transfer apparatus is provided wherein a CPB is emitted from the CPB source, is focused by first and second condenser lenses, and is illuminated onto a mask. A deflector deflects the CPB to a selected subfield of the mask. The CPB transmitted by subfield is projected by a first projection lens toward a back-focal-plane aperture. The portion of the CPB that passes through the back-focal-plane aperture is projected by a second projection lens onto a wafer. Coulomb-effect-induced shifts in focal-point position, and changes in image magnification, projected-image rotation, and astigmatic blur and astigmatic distortions of the image are each corrected by application of electric current to respective components of a correction system, the correction system preferably comprising a set of correction lenses and two stigmators.

Abstract: Methods are disclosed for improving the accuracy of pattern registration between various layers formed on a sensitive substrate by microlithography using a charged-particle beam, especially registration accuracy as affected by rotation of image portions relative to corresponding image portions in an earlier applied layer. Errors in rotational angle of a pattern transferred to the n.sup.th layer and the arrangement direction of the transferred pattern on the substrate are measured. During projection of the (n+m).sup.th (e.g., the (n+1).sup.th) layer, the rotational angle of images that have passed through the mask subfields is corrected according to the measured rotational angle. Also, the deflection direction of the images on the substrate that have passed through the mask subfields is corrected according to the measured arrangement direction. The transfer subfields in the (n+m).sup.th layer can be accurately stitched together and corresponding transferred pattern in the n.sup.th and (n+m).sup.

Abstract: Charged-particle-beam transfer-exposure apparatus are disclosed exhibiting reduced hybrid distortion. A charged particle beam passes through a mask and through a projection-lens assembly to form an image of a selected mask region on a wafer. Signals corresponding to the functions d.sub.x1 (X.sub.w, Y.sub.w, Z, I, s), d.sub.y1 (X.sub.w, Y.sub.w, Z, I, s), d.sub.x2 (X.sub.w, Y.sub.w, Z, I, s), d.sub.y2 (X.sub.w, Y.sub.w, Z, I, s), . . . , are generated by a computer and routed to respective deflectors to minimize deflection aberrations, wherein X.sub.w, Y.sub.w are the coordinates of the deflected transfer region on the wafer, Z is the wafer height, I is the beam current passing through the pattern area in a mask region, and s is a variable pertaining to scattering of charged particles in the pattern. The signals routed to the various deflectors also take into account the function g(X.sub.w, Y.sub.w, Z, I, s) which corrects deflection distortion.

Abstract: Charged-particle-beam (CPB) exposure apparatus are disclosed that project a mask pattern onto a substrate while reducing aberrations. The mask pattern is typically subdivided into mask subfields, separated from each other by struts or the like, that are individually projected onto the substrate in an ordered manner to produce a die pattern in which constituent transfer subfields are properly stitched together. The apparatus comprises a projection-optical system, comprising multiple deflectors, between the mask and the substrate. The deflectors are connected to and controllably actuated by a controller in a manner serving to reduce third-order deflection aberrations to zero. Control of the deflectors is such that the charged-particle beam, propagating from the mask, has a trajectory that is a function of the location of the beam in a mask plane transverse to the optical axis and the location of the beam in a substrate plane transverse to the optical axis.

Abstract: Charged-particle-beam projection-exposure apparatus are disclosed for transferring patterns from a mask to a sensitized substrate. By measuring the height and tilt of regions of the sensitized substrate relative to the location of the projected image of the mask before the regions are exposed to the charged particle beam, the charged-particle-beam optical system and the wafer tilt and position can be corrected, maintaining a high-quality image of the mask on the sensitized substrate. Measuring the height and tilt of a region of the sensitized substrate before exposure of that region begins has several advantages. The measurements permit adjustments so that high-resolution images of the mask are transferred to the sensitized substrate even if wafer height and tilt vary rapidly. In addition, because the measurements of tilt and height occur away from the exposure region, height and tilt measuring devices do not restrict the placement or size of charged-particle-beam optical elements.

Abstract: A scan type electron microscope has an electron beam generating source for generating an electron beam with which a sample is irradiated; a sample chamber, supplied with a gas for effecting a gas amplification, for housing the sample; a secondary electron detecting means, installed in the sample chamber, for detecting secondary electrons gas-amplified by the gas after being generated from the sample with the irradiation of the electron beam; and an electrode, disposed between the sample and the secondary electron detecting means, for absorbing positive ions produced when the secondary electrons are gasamplified by the gas. The electrode may be constituted by a further fine tube extended from a pressure limiting aperture to a position just above the sample and formed with a path of the electron beam. The absorption of the positive ions prevents a positive charge-up of the sample, whereby a voltage between the sample and the secondary electron detecting means can be kept at a fixed level.

Abstract: A data processing system comprises a main memory for receiving an input access virtual address, data, and a write instruction, converting the access virtual address into a real address, storing the data at the real address in accordance with the write instruction, and generating a response upon writing of the data; an execution section for selectively and sequentially executing a series of microinstructions in accordance with an input wait signal, generating a write instruction and an access virtual address upon execution of a write microinstruction, and outputting the write instruction, the access virtual address, and the data to the main memory; and a controller for generating a wait signal in accordance with the access virtual address and the write instruction from the execution section, and the response from the main memory, and outputting the wait signal to the execution section.

Abstract: A magnetic field gradient coil system for use in a magnetic resonance imaging apparatus forming a magnetic field gradient in a direction of a Z-axis of an X, Y, Z orthogonal coordinate system having its origin at a selected position in the imaging apparatus comprises one pair of first coils and one pair of second coils having their centers on the Z-axis and having the same radius, the coils of each coil pair disposed symmetrically with respect to an XY plane including the origin, the coils of the second coil pair disposed more distant from the origin than the coils of the first coil pair, the coils of the first and second coil pairs disposed on one side of the origin supplied with current in the same direction, the coils disposed on the other side of the origin supplied with current opposite to the direction of current in the coils on the one side of the origin, each of the coils of the first coil pair disposed where the value of the Z-axis magnetic field component of first order at a selected position on the

Abstract: A method of inhibiting polymerization of styrenes is disclosed, comprising the process of jointly using nitrosophenols and p-tertiarybutyl catecol for composing the polymerization inhibiting agent usable during the distillation process of styrenes.

Abstract: A cache memory control system has a segment descriptor with a 1-bit cache memory unit designation field, and a register for storing data representing the cache memory unit designation field. An output from the register is supplied to one cache memory unit, whereas inverted data of the output from the register is supplied to the other cache memory unit.

Abstract: A superconductor which includes a housing of a highly pure copper having a slot therein for accommodating a plurality of monolithic superconductor members and a reinforcing member. A highly pure aluminum lid or cover is adapted to be disposed in an opening of the slot, with outer surfaces of the lid or cover having arranged thereon highly pure copper. The lid or cover, the monolithic superconductor members, the reinforcing member, and the housing are integrated and bonded together by a bonding material such as, for example, solder.

Abstract: A side-valve type internal-combustion engine has a cylinder head formed with a recess or recesses each of which forms a combustion chamber with the associated cylinder and which is large enough to permit the alternate flow of suction or exhaust gas between the suction (inlet) or exhaust valve and the cylinder. In plan, the configuration of the recess is generally L-shaped and covers the both valves and part of the cylinder. One leg of the L-shaped recess provides a straight line passage between the suction or inlet valve and the cylinder, while the exhaust valve and the cylinder are connected in series by the one leg of the recess from the cylinder to the suction valve and then by the other leg from the suction valve to the exhaust valve. The height of the recess is reduced in the region directly above the exhaust valve to a level considerably lower than the rest of the recess so that the upper wall surface of the recess is very close to the exhaust valve when it is in its uppermost position.