Abstract: Microlithographic exposure methods and microelectronic-device fabrication methods are disclosed that include a microlithography step in which a pattern is defined on a segmented reticle. The pattern includes pattern elements split among respective subregions that are exposed onto a resist layer of a wafer or other substrate using a charged-particle-beam (CPB) microlithography apparatus. In a first reticle subregion, a first pattern-element portion is defined having a mating end that is complementary to a mating end of a second pattern-element portion defined in a second reticle subregion. A mating end, rather than simply being blunt, typically has a protrusion and/or recess. If a first mating end has a protrusion, the protrusion is complementary to a corresponding protrusion on a second mating end, or to a recess on the second mating end. A mating end can have both at least one protrusion and at least one recess.

Abstract: Fiducial mark bodies are provided for use in CPB microlithography apparatus and methods. Such bodies are especially useful for attachment to the wafer stage of such apparatus, for measuring a distance between a reference position of the CPB-optical system of the apparatus and a reference position of an optical-based alignment sensor of the apparatus. The mark bodies provide improved accuracy of these and other positional measurements. A typical mark body is made of a substrate plate (e.g., quartz or quartz-ceramic) having a low coefficient of thermal expansion. Mark elements are defined on the substrate plate by a layer of heavy metal (e.g. are Ta, W, or Pt). The mark body includes a surficial or interior layer of an electrically conductive light metal that prevents electrostatic charging of the mark body and can be connected to ground.

Abstract: Wafer chucks and related substrate-holding devices are disclosed for use in holding the substrate while any of various processes are being performed on the substrate. For example, the devices are useful for holding a semiconductor wafer during microlithography performed on the wafer, especially in a vacuum environment. The wafer chucks can include devices for confirming that the substrate is adhered completely and properly to the “adhesion surface” of the wafer chuck before commencing flow of a heat-transfer gas to the wafer chuck. Such status-confirming devices can be, e.g., height gauges or electrical contacts that measure an electrical property that changes with changes in contact pressure of the contacts against the substrate.

Abstract: Methods are disclosed for determining and accounting for errors in a moving mirror of an interferometer used for determining the position of a stage or the like in a microlithography system or other system requiring highly accurate positioning. In an embodiment, straight lines that approximate respective curves of mirror surfaces (29a), (29b) are determined with respect to a coordinate system defined on a wafer table. The straight lines are determined by a least-squares method. Also determined are angles (&PSgr;u) and (&PSgr;v) formed by straight lines (Lu) and (Lv) relative to coordinate axes (u) and (v), respectively. Intersections with the coordinate axes u, v are (Bu, 0) and (0, Bv), respectively. The distances to points U1 and V1 on mirror surfaces 29a and 29b with respect to straight lines Lu and Lv are &ohgr;u(v) and &ohgr;v(u), respectively, and the angles with the tangent lines of the points U1 and V1 are &bgr;u(v) and &bgr;v(u), respectively.

Abstract: Methods and devices are disclosed for controlling blur resulting from the space-charge effect and geometrical aberration in a charged-particle-beam microlithography apparatus. Based on the pattern-element densities of the exposure units to be transferred to the substrate, a relationship between the total blur and the beam semi-angle, the current density, and/or the beam-acceleration voltage is determined. An optimal beam semi-angle, current density, and/or beam-acceleration voltage is calculated to: (1) minimize the blur during the transfer-exposure of an exposure unit having a certain pattern-element density; (2) make the blur constant during the transfer-exposure of a group of exposure units having various pattern-element densities; or (3) maximize the patterned-beam current during the transfer-exposure of an exposure unit having a certain pattern-element density and blur tolerance.

Abstract: Charged-particle-beam microlithography apparatus are disclosed that include a system for performing alignment of a reticle and a wafer. The wafer includes at least one alignment mark that is irradiated by a charged particle beam. The irradiated alignment mark produces backscattered electrons that are detected, resulting in a backscattered-electron (BSE) data signal. Among various candidate techniques for measuring the position of the alignment mark, the apparatus automatically selects (based on the BSE data signal) a particular technique that will provide the best accuracy under the prevailing conditions of measurement.

Abstract: Reticles and reticle-evaluation methods are provided that allow charged-particle-beam (CPB) reticles to be evaluated quickly and accurately. The reticles include one or more device-pattern regions. Alignment-pattern regions are arranged in respective rows along the “upper” and “lower” edges of the device-pattern region(s). Each device-pattern region includes multiple subfields into which a device pattern is divided and defined. Also flanking each device-pattern region are respective evaluation-pattern regions situated along the “left” and “right” edges of the device-pattern region(s). Each evaluation-pattern region includes multiple small membrane regions each having a respective subfield that defines a respective evaluation pattern. The evaluation pattern includes various lines having respective widths, positions, and shapes that are measured and evaluated.

Abstract: Electrostatic wafer chucks are disclosed for use in holding a substrate (e.g., semiconductor wafer) during processing of the substrate in a vacuum chamber or other reduced-pressure environment. A representative wafer chuck provides improved control of the vacuum level in the vacuum environment while providing a mechanism (lift pins) for raising and lowering the substrate relative to the chuck. The chuck body defines a wafer-mounting surface that contacts the under-surface of the substrate. The chuck body defines a gap between the under-surface of the substrate and the chuck for conducting a heat-transfer gas, and multiple feed-through holes extending through the chuck body. Surrounding each feed-through hole is at least a first protrusion configured to separate the respective feed-through hole from the gap. A respective lift pin in each feed-through hole extends from the chuck body across the gap to the under-surface of the substrate.

Abstract: Microlithographic exposure methods and microelectronic-device fabrication methods are disclosed that include a microlithography step in which a pattern is defined on a segmented reticle. The pattern includes pattern elements split among respective subregions that are exposed onto a resist layer of a wafer or other substrate using a charged-particle-beam (CPB) microlithography apparatus. In a first reticle subregion, a first pattern-element portion is defined having a mating end that is complementary to a mating end of a second pattern-element portion defined in a second reticle subregion. A mating end, rather than simply being blunt, typically has a protrusion and/or recess. If a first mating end has a protrusion, the protrusion is complementary to a corresponding protrusion on a second mating end, or to a recess on the second mating end. A mating end can have both at least one protrusion and at least one recess.

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: Fiducial mark bodies are provided for use in CPB microlithography apparatus and methods. Such bodies are especially useful for attachment to the wafer stage of such apparatus, for measuring a distance between a reference position of the CPB-optical system of the apparatus and a reference position of an optical-based alignment sensor of the apparatus. The mark bodies provide improved accuracy of these and other positional measurements. A typical mark body is made of a substrate plate (e.g., quartz or quartz-ceramic) having a low coefficient of thermal expansion. Mark elements are defined on the substrate plate by a layer of heavy metal (e.g. are Ta, W, or Pt). The mark body includes a surficial or interior layer of an electrically conductive light metal that prevents electrostatic charging of the mark body and can be connected to ground.

Abstract: Fiducial mark bodies are provided for use in CPB microlithography apparatus and methods. Such bodies are especially useful for attachment to the wafer stage of such apparatus, for measuring a distance between a reference position of the CPB-optical system of the apparatus and a reference position of an optical-based alignment sensor of the apparatus. The mark bodies provide improved accuracy of these and other positional measurements. A typical mark body is made of a substrate plate (e.g., quartz or quartz-ceramic) having a low coefficient of thermal expansion. Mark elements are defined on the substrate plate by a layer of heavy metal (e.g. are Ta, W, or Pt). The mark body includes a surficial or interior layer of an electrically conductive light metal that prevents electrostatic charging of the mark body and can be connected to ground.

Abstract: Electrostatic wafer chucks are disclosed for use in holding a substrate (e.g., semiconductor wafer) during processing of the substrate in a vacuum chamber or other reduced-pressure environment. A representative wafer chuck provides improved control of the vacuum level in the vacuum environment while providing a mechanism (lift pins) for raising and lowering the substrate relative to the chuck. 1. The chuck body defines a wafer-mounting surface that contacts the under-surface of the substrate. The chuck body defines a gap between the under-surface of the substrate and the chuck for conducting a heat-transfer gas, and multiple feed-through holes extending through the chuck body. Surrounding each feed-through hole is at least a first protrusion configured to separate the respective feed-through hole from the gap. A respective lift pin in each feed-through hole extends from the chuck body across the gap to the under-surface of the substrate.

Abstract: Microelectronic-device fabrication methods are disclosed that include a microlithography step in which a pattern is defined on a mask divided into multiple subregions. The pattern includes pattern elements split among respective subregions that are exposed onto a resist layer of a wafer using a charged-particle-beam microlithography apparatus. In a first mask subregion, a first pattern-element portion is defined having a mating end that is complementary to a mating end of a second pattern-element portion defined in a second mask subregion. A mating end, rather than simply being blunt, typically has a protrusion and/or recess. If a first mating end has a protrusion, the protrusion is complementary to a corresponding protrusion on a second mating end, or to a recess on the second mating end. A mating end can have both at least one protrusion and at least one recess.

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: Charged-particle-beam microlithography apparatus are disclosed that include a system for performing alignment of a reticle and a wafer. The wafer includes at least one alignment mark that is irradiated by a charged particle beam. The irradiated alignment mark produces backscattered electrons that are detected, resulting in a backscattered-electron (BSE) data signal. Among various candidate techniques for measuring the position of the alignment mark, the apparatus automatically selects (based on the BSE data signal) a particular technique that will provide the best accuracy under the prevailing conditions of measurement.

Abstract: Methods are disclosed for performing reticle-substrate alignments in the context of charged-particle-beam (CPB) microlithography. More specifically, the subject methods pertain to detecting an amount of relative rotation between the “transfer-receiving” (e.g., substrate) side and the “transfer-originating” (e.g., reticle) side in one operation simply by detecting marks that are disposed near an axis of the CPB-optical system. A charged particle beam is passed through an alignment mark(s) situated relative to an alignment axis of the reticle and thus indicates reticle orientation. One or more respective index marks are defined on the substrate relative to an alignment axis of the substrate, thereby indicating substrate orientation. E.g., two index marks can be provided on the substrate, one convex and the other concave, but otherwise similarly shaped. The index marks can be situated linearly aligned with each other or at an angle to each other.

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: Wafer chucks and related substrate-holding devices are disclosed for use in holding the substrate while any of various processes are being performed on the substrate. For example, the devices are useful for holding a semiconductor wafer during microlithography performed on the wafer, especially in a vacuum environment. The wafer chucks can include devices for confirming that the substrate is adhered completely and properly to the “adhesion surface” of the wafer chuck before commencing flow of a heat-transfer gas to the wafer chuck. Such status-confirming devices can be, e.g., height gauges or electrical contacts that measure an electrical property that changes with changes in contact pressure of the contacts against the substrate.