Abstract: Charged-particle-beam (CPB) apparatus and methods are disclosed that achieve efficient correction of imaging conditions such as shape-astigmatic aberrations, etc., caused by differences in the distribution of pattern elements within respective subfields of the reticle. Indices based on the pattern-element distributions within subfields are stored, together with corresponding optical-correction data for the subfields. As the subfields are exposed, respective data are recalled and the exposure is performed with optical corrections made according to the data. The indices are determined beforehand from pattern data at time of reticle manufacture. The tabulated data are rewritable with changes in apparatus parameters such as beam-current density and beam-divergence angle. Intermediate data can be determined by interpolation of tabulated data.

Abstract: Reticles and apparatus for performing charged-particle-beam microlithography, and associated methods, are disclosed, in which the pattern to be transferred to a sensitive substrate is divided according to any of various schemes serving to improve throughput and pattern-transfer accuracy. The methods and apparatus are especially useful whenever a divided stencil reticle is used that includes complementary pattern portions.

Abstract: Methods are disclosed for reducing effects of thermal expansion of a sensitive substrate arising during microlithographic exposure of the substrate using a charged particle beam. Thermal expansion ordinarily causes lateral shift of exposure position of dies (chips) on the substrate which tends to reduce the positional accuracy with which images of the dies are formed on the substrate. Generally, regions of the substrate where entire dies are formed are exposed first, followed by regions (especially peripheral regions) exposed with only portions of dies. In addition, the substrate can be mounted on a wafer chuck configured to circulate a heat-transfer gas in contact with the substrate to remove heat from the substrate. In addition, the wafer chuck can be maintained at a constant temperature by circulating a liquid coolant through a conduit in the body of the wafer chuck.

Abstract: Substrate-holding devices (“wafer chucks”) and methods are disclosed for use in any of various apparatus and methods for processing a substrate. For example, the wafer chucks are especially useful with microlithography apparatus and methods, especially such apparatus and methods employing a charged particle beam. The devices and methods achieve controlled reduction of substrate heating and rapid substrate exchange during substrate processing. The wafer chuck has an adhesion surface and a heat-transfer-gas (HTG) channel. In an exemplary configuration, the HTG channel is connected to an HTG supply and a gas-evacuation system. Heat-transfer gas is caused to flow through the channel during a predetermined time period when the substrate is being held (typically by electrostatic force) on the adhesion surface. At a first time instant, execution of the fabrication process on the substrate (adhered to the adhesion surface) is commenced.

Abstract: Segmented reticles are disclosed for used with charged-particle-beam projection-microlithography apparatus. Such reticles comprise multiple mask subfields and a support grid, of intersecting struts, having an upstream-facing surface and a downstream-facing surface. Alignment marks are situated on the upstream- or downstream-facing surface. The projection-microlithography apparatus comprise a beam source, an illumination system, and a subfield-selection deflector. A second deflector downstream of the reticle further deflects the beam to impart a change in a parameter of the beam to correct reticle distortion. A correction-optical system can further change one or more characteristics of the beam downstream of the reticle to correct reticle distortion. A detector determines actual alignment-mark positions relative to ideal positions, and a controller calculates therefrom a required change to be imparted to the charged particle beam to correct the reticle distortion.

Abstract: Projection-microlithography masks and methods are disclosed for aligning a mask in a pattern-transfer apparatus and transferring a pattern image as defined by the mask onto a sensitive substrate using a charged-particle beam or other suitable microlithography energy source. A mask of the present invention can include a pattern defined on a plurality of thin mask reticles or films. The mask reticles are secured to a single retention member. The mask further includes fiducial marks defined on the retention member, and fine alignment marks defined on each of the mask reticles, to facilitate alignment of the mask and correction of pattern-image errors resulting from distortion or movement of the mask reticles prior to exposing the substrate to the pattern image.

Abstract: Projection-microlithography masks and methods are disclosed for aligning a mask in a pattern-transfer apparatus and transferring a pattern image as defined by the mask onto a sensitized substrate using a charged-particle beam or other suitable microlithography energy source. A mask of the present invention can comprise a pattern defined on a plurality of thin mask reticles or films. The plurality of mask reticles are secured to a single retention member. The mask further comprises fiducial marks, defined on the retention member and fine-alignment marks defined on each of the mask reticles, to facilitate alignment of the mask and correction of pattern-image errors resulting from distortion or movement of the mask reticles prior to exposing the substrate to the pattern image.

Abstract: Apparatus and methods are disclosed for performing highly precise mark detection by obtaining a large signal as a result of the efficient capture of secondary electrons (SEs) emitted from a surface of a specimen. A charged-particle beam is directed at a location (e.g., a mark) on the specimen (e.g., reticle or wafer). SEs emitted from the location are detected using one or more secondary-electron collectors or detectors. To guide the SEs toward the secondary-electron collectors or detectors, a magnetic flux is created that extends radially outward in the vicinity of the surface of the specimen. E.g., an objective lens is situated above the specimen adjacent the specimen surface, and an electromagnetic lens is placed below the specimen adjacent the lower surface of the specimen. The magnetic fields produced by these lenses can be mutually repulsive to form a resultant magnetic flux near the upper surface of the specimen that extends radially outward parallel with the upper surface of the specimen.

Abstract: Mask holders are disclosed for holding a mask used during a microlithographic exposure. The mask holder comprises an outer frame and an inner frame. The outer frame contacts the periphery of a main surface of the mask to hold the mask. The inner frame is connected to the outer frame, and contacts an inner portion of said main surface of the mask to hold the mask. The mask holder can include one or more electrostatic and/or vacuum chucks, a thermally conductive material that contacts the mask whenever the mask is being held by the mask holder, and/or an electrically conductive material to discharge accumulated electrical charge on the mask during use.