摘要:
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.
摘要:
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.
摘要:
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.
摘要:
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.
摘要:
A substrate conveyor apparatus carries a substrate on which patterns are formed, carries the substrate in a state protected by a protective cover when the substrate is not used, and carries a cover protection means that covers the inner surface of the protective cover when the substrate is used. The substrate conveyor apparatus has a grounding means that grounds the substrate or the protective cover.
摘要:
With respect to a substrate conveyor apparatus that, being a substrate conveyor apparatus that carries substrates on which patterns are formed, carries the substrates in a state protected by a protective cover when the substrate is not used, a substrate conveyor apparatus having a cover protection means that conceals the inner surface of the protective cover when the substrate is used.
摘要:
Microlithography methods and apparatus are disclosed that allow reticle deformations to be measured and corrected quickly and accurately. Multiple alignment marks (comprising a “first set” and “second set” of reticle-position-measurement marks) are formed on the reticle. A first set of reticle-deformation data is obtained by detecting the positions of at least some of the first set of reticle-position-measurement marks using an inspection device that is separate from the microlithography apparatus with which the reticle will be used for making lithographic exposures. The first set of reticle-deformation data is stored in a first memory. The reticle then is mounted in the microlithography apparatus, in which a second set of reticle-deformation data is obtained by detecting the positions of at least some of the second set of reticle-position-measurement marks. The second set of reticle-deformation data is stored in a second memory. Lithographic exposures are performed, using the reticle so measured, while correcting the respective positions and/or deformations of the respective subfields on the fly, according to both sets of reticle-deformation data recalled from the respective memories.
摘要:
An exposure apparatus transfers a pattern from a mask onto a sensitive substrate. A film protects the mask, and a film frame, between the mask and the film, holds the film spaced away from a surface of the mask. The film has a first transmittance for radiation of a necessary wavelength and has a second transmittance for radiation of an unnecessary wavelength; the first transmittance is higher than the second transmittance. The film might reflect or absorb the unnecessary wavelength. The necessary wavelength may be an exposure wavelength and may also be in the range of extreme ultra violet radiation. An atmosphere around the mask transitions from an air atmosphere to a reduced-pressure atmosphere, or from a reduced-pressure atmosphere to an air atmosphere, at a speed that allows a difference between a pressure applied to one surface of the film and a pressure applied to the other surface of the film to be held at a predetermined value or smaller.
摘要:
Methods and apparatus for alignment of masks and wafers in charged-particle-beam (CPB) pattern-transfer use optical position sensors to determine the positions of a mask or a mask stage with respect to an axis of a CPB optical system. The optical position sensor uses optical reference marks provided on the mask or mask stage. Determination of the position of the mask of the mask stage permits a coarse alignment of the mask or the mask stage. CPB reference marks are provided on masks, mask stages, wafers, and wafer stages, permitting alignment of the mask stage or the mask with respect to the wafer stage or wafer, respectively, using the charged particle beam. The charged particle beam is scanned with respect to the wafer or wafer-stage CPB reference marks to determine a deflection corresponding to an alignment of the CPB reference marks of the mask and wafer (or mask stage and wafer stage). Use of the charged particle beam for such alignment permits a fine alignment.
摘要:
Electrostatic reticle chucks are disclosed that provide strong reticle-holding force and that can be used in a subatmospheric-pressure environment as encountered in charged-particle-beam microlithography. The chucks are suited especially for holding reticles made from a silicon reticle substrate. The attractive force is established between a reticle-contacting surface of the chuck comprising a dielectric material, and the reticle. Depthwise beneath the dielectric material is at least one electrode. The dielectric material has a property such that, when the electrode is energized, the reticle is attracted to the reticle-contacting surface by a Johnsen-Rahbek force. To such end, by way of example, the dielectric material has a volume resistivity of no greater than 1013 &OHgr;-cm. The Johnsen-Rahbek force holds the reticle much more strongly than the Coulomb force produced by conventional reticle chucks.