Pattern Mask Patents (Class 378/35)
  • Patent number: 6455204
    Abstract: An X-ray mask including (a) an X-ray permeable membrane and (b) an X-ray absorber formed in a pattern on the X-ray permeable membrane. The X-ray absorber is composed of an alloy having one of the following groups: (a) tantalum (Ta), ruthenium (Ru), and germanium (Ge); (b) tantalum (Ta), ruthenium (Ru), and silicon (Si); (c) rhenium (Re) and germanium (Ge); and (d) tungsten (W) and germanium (Ge). The X-ray mask provides advantageous features, such as having high ability for absorbing X-ray therein, possible reproduction of a thin film having low stress and having a densified crystal structure.
    Type: Grant
    Filed: September 19, 2000
    Date of Patent: September 24, 2002
    Assignee: NEC Corporation
    Inventor: Takuya Yoshihara
  • Publication number: 20020132171
    Abstract: The present invention provides a method of and system for reducing the absorption of light by opaque material in a photomask. The method includes providing a photomask substrate, and applying an opaque material to one side of the photomask substrate. The interface between the opaque material and photomask substrate reflects at least 80 percent of the light through the photomask.
    Type: Application
    Filed: December 20, 2000
    Publication date: September 19, 2002
    Applicant: Advanced Micro Devices, Inc.
    Inventors: Harry J. Levinson, Fan Piao, Christopher A. Spence
  • Patent number: 6453458
    Abstract: The present invention provides a method for segmenting and mapping a two-dimensional conventional circuit pattern to a flat mask for projection onto a three-dimensional surface. The circuit pattern is first segmented into a plurality of circuit segments enclosed in a plurality of base units of an imposed grid system. Subsequently, locations and the boundary conditions for a plurality of mask segments on the mask are determined such that no unneeded overlapping at the boundaries of the projected image on the spherical shaped semiconductor device is possible. The mask, along with a photolithography system having a plurality of mirrors, projects the circuit pattern onto the spherical shaped semiconductor device.
    Type: Grant
    Filed: July 9, 1999
    Date of Patent: September 17, 2002
    Assignee: Ball Semiconductor, Inc.
    Inventors: Atsuyuki Fukano, Zhiqiang Feng, Hideki Koide
  • Patent number: 6444372
    Abstract: A reticle or mask for use in projecting a circuit pattern on a photosensitive resist covered wafer having a transparent substrate with a reflective or dielectric layer thereon. An opaque or blocking layer, for example chrome or chromium, is placed over the reflective layer. The opaque layer then has a predetermined circuit pattern etched therein. In one embodiment, the opaque layer and the reflective layer are the same size. In another embodiment, the opaque layer has a size larger than the reflective layer. This permits the opaque layer to be adjacent the substrate which is advantageous when projection optics having a high numerical aperture are used. The reticle of the present invention has particular advantage when high throughput photolithographic tools are used having an illumination source of high energy flux with a wavelength of between 157 nanometers and 365 nanometers. Illumination in this wavelength range has considerable absorption in chrome, a common opaque material used in reticles.
    Type: Grant
    Filed: October 25, 1999
    Date of Patent: September 3, 2002
    Assignee: SVG Lithography Systems, Inc.
    Inventor: Andrew W. McCullough
  • Publication number: 20020118347
    Abstract: A print circuit board is demarcated with arbitrary areas. The print circuit board at one area is partly sucked and fixed on an alignment stage. After alignment with a mask, a pattern of the mask is transferred to the board. Next, shift is made to another area to repeat the same operation, thereby sequentially exposing all the areas to light.
    Type: Application
    Filed: December 18, 2001
    Publication date: August 29, 2002
    Inventor: Takahiro Shimada
  • Patent number: 6441885
    Abstract: Thermal distortion of reticles or masks can be significantly reduced by emissivity engineering, i.e., the selective placement or omission of coatings on the reticle. Reflective reticles so fabricated exhibit enhanced heat transfer thereby reducing the level of thermal distortion and ultimately improving the quality of the transcription of the reticle pattern onto the wafer. Reflective reticles include a substrate having an active region that defines the mask pattern and non-active region(s) that are characterized by a surface that has a higher emissivity than that of the active region. The non-active regions are not coated with the radiation reflective material.
    Type: Grant
    Filed: July 10, 2001
    Date of Patent: August 27, 2002
    Assignee: EUV LLC
    Inventors: Steven E. Gianoulakis, Avijit K. Ray-Chaudhuri
  • Publication number: 20020114999
    Abstract: A thin transition-metal based scattering layer of a mask blank for use in EPL systems is formed by providing the thin transition-metal scattering layer directly over membrane layers on a lot of substrates, thereby forming a continuous contact between the single transition metal-based scattering layer and the membrane layer. Preferably, the single transition metal-based scattering layer is a single tantalum-silicon composite scattering layer having a stoichiometry of TaxSi. The deposition parameters for depositing the thin transition-metal based scattering layer are adjusted to provide the scattering layer uniformly over all substrates within the lot. A first substrate from the lot of substrates is then selected, an initial stress measurement of the scattering layer is determined and then the substrate is annealed at a first temperature.
    Type: Application
    Filed: December 21, 2000
    Publication date: August 22, 2002
    Applicant: International Business Machines Corporation
    Inventors: Cameron J. Brooks, Kenneth C. Racette
  • Publication number: 20020110743
    Abstract: In a reflection type mask blank for EUV exposure, a multilayer film is formed on a substrate to reflect EUV light. An intermediate layer is formed on the multilayer film. An absorber layer is formed on the intermediate layer to absorb the EUV light The intermediate layer is formed by a material containing Cr and at least one element selected from the group consisting of N, O, and C.
    Type: Application
    Filed: February 14, 2002
    Publication date: August 15, 2002
    Applicant: HOYA CORPORATION
    Inventors: Tsutomu Shoki, Morio Hosoya
  • Patent number: 6428939
    Abstract: A clear phase shifting mask, particularly adapted to imaging nanostructures using X-ray lithography, includes a membrane having generally planar top and bottom surfaces the membrane being substantially transparent to the incoming radiation. In addition, the mask includes a pair of phase shift regions supported on the membrane, each of the regions defining a corresponding edge. During an imaging operation, the mask generates an aerial image defining, for each of the corresponding edges, an edge bright peak and an edge dark peak. By suitable choices of widths on the mask, the edge bright peaks can be caused to constructively interfere to form an enhanced intensity image bright peak. According to another embodiment, aphase shifting mask that images two-dimensional features on a target using the bright peak of the corresponding aerial image includes a membrane and a phase shifting material supported by the membrane.
    Type: Grant
    Filed: March 20, 2001
    Date of Patent: August 6, 2002
    Assignee: Wisconsin Alumni Research Foundation
    Inventors: Lei Yang, James W. Taylor, Francesco Cerrina
  • Publication number: 20020101956
    Abstract: An X-ray projection exposure apparatus includes a mask chuck, a wafer chuck, an X-ray illuminating system, and an X-ray projection system. The masks chuck holds a reflection X-ray mask having a mask pattern thereon. The wafer chuck holds a wafer onto which the mask pattern is transferred. The X-ray illuminating system illuminates the reflection X-ray mask, held by the mask chuck, with X-rays. The X-ray projection optical system projects the mask pattern of the reflection X-ray mask onto the wafer held by the wafer chuck with a predetermined magnification. The mask chuck includes a mechanism for generating static electricity for attracting and holding the reflection X-ray mask by an electrostatic force. The invention also includes a device manufacturing method using such an X-ray projection exposure apparatus to transfer a mask pattern onto the wafer using the X-ray projection exposure apparatus.
    Type: Application
    Filed: March 7, 2002
    Publication date: August 1, 2002
    Inventors: Shinichi Hara, Masami Tsukamoto
  • Publication number: 20020102472
    Abstract: A method for measuring critical dimensions on photomasks, and more specifically to a method for measuring critical dimensions on photomasks using an electrical test structure. The test structure 30 may be comprised of a cross resistor 32 for van der Pauw sheet resistance measurements, a bridge resistor 34, and a split-bridge resistor 36.
    Type: Application
    Filed: January 31, 2001
    Publication date: August 1, 2002
    Inventor: David Y. Chan
  • Publication number: 20020098422
    Abstract: In a method of annealing a workpiece which has a substrate and a light absorption film on the substrate, a laser beam is irradiated onto a workpiece to only heat the light absorption film without any temperature rise of the substrate and to anneal an internal stress of the light absorption film. A wavelength of the laser beam is selected so as to be absorbed into the light absorption film. The workpiece may be a photo mask blank (or a photo mask) or a phase shift mask blank (or a phase shift mask).
    Type: Application
    Filed: December 3, 2001
    Publication date: July 25, 2002
    Applicant: HOYA CORPORATION
    Inventor: Osamu Nozawa
  • Patent number: 6421820
    Abstract: A semiconductor device can be fabricated using a photomask that has been modified using an assist feature design method (see e.g., FIG. 4A) based on normalized feature spacing. Before the device can be fabricated, a layout of original shapes is designed (402). For at least some of the original shapes, the width of the shape and a distance to at least one neighboring shape are measured (404). A modified shape can then be generated by moving edges of the original shape based on the width and distance measurements (406). This modification can be performed on some or all of the original shapes (408). For each of the modified shapes, a normalized space and correct number of assist features can be computed (410). The layout is then modified by adding the correct number of assist features in a space between the modified shape and the neighboring shape (412). This modified layout can then be used in producing a photomask, which can in turn be used to produce a semiconductor device.
    Type: Grant
    Filed: December 13, 1999
    Date of Patent: July 16, 2002
    Assignees: Infineon Technologies AG, Internation Business Machines Corporation
    Inventors: Scott M. Mansfield, Lars W. Liebmann, Shahid Butt, Henning Haffner
  • Patent number: 6418187
    Abstract: An X-ray mask structure and X-ray exposure method using the same are disclosed, wherein the mask has an X-ray absorptive material pattern, a supporting film for supporting the pattern, and a holding frame for holding the supporting film, wherein a suction port is arranged to be communicated with an external gas drawing system, and wherein a supply port is provided so that a gas can be supplied therethrough, for prevention of dust adhesion to the mask.
    Type: Grant
    Filed: July 9, 1999
    Date of Patent: July 9, 2002
    Assignee: Canon Kabushiki Kaisha
    Inventors: Keiko Chiba, Shigeru Terashima
  • Patent number: 6415431
    Abstract: A method and apparatus are provided for repairing clear defects in photomasks such as attenuated photomasks having a patterned MoSi film on a glass substrate. The method and apparatus use an energy source in the form of an energy beam to undercut the sidewalls of the clear defect forming a clear defect having angled sidewalls. A repair material is then deposited in the angled opening to repair the clear defect. In a preferred embodiment, two repair steps are used with the first repair step using a first repair material to deposit a first repair material on the angled sidewalls of the clear defect and a second step using a second repair material to contact the first repair material and to fill the remainder of the clear defect opening. An apparatus for repairing clear defects and photomasks repaired by the method and apparatus of the invention is also provided.
    Type: Grant
    Filed: February 18, 2000
    Date of Patent: July 2, 2002
    Assignee: International Business Machines Corporation
    Inventor: Timothy E. Neary
  • Patent number: 6413681
    Abstract: A diamond film is formed on a silicon single crystal substrate by a microwave plasma CVD or hot filament CVD process using a source gas. The source gas consists essentially of 3.0% to 8.0% by volume of CH4, 87.0% to less than 97.0% by volume of H2, and more than 0.0% to 5.0% by volume of O2. A diamond film having a sufficient crystallinity to serve as a membrane for x-ray lithography and a precisely controlled tensile stress can be formed.
    Type: Grant
    Filed: November 24, 1999
    Date of Patent: July 2, 2002
    Assignee: Shin-Etsu Chemical Co., Ltd.
    Inventor: Hitoshi Noguchi
  • Publication number: 20020081498
    Abstract: A reflective membrane mask is composed at least partially of an electrically conductive material and is aligned horizontally over a sample to be processed. Bending of the reflective membrane mask is compensated for by disposing an electrode plate above the membrane mask and parallel to it, which electrode plate is provided with a number of electrodes that are electrically isolated from one another. Electrostatic forces, that correct for any deformation of the membrane mask, are produced by applying an electrical potential difference between each electrode and the membrane mask.
    Type: Application
    Filed: October 17, 2001
    Publication date: June 27, 2002
    Inventor: Albrecht Ehrmann
  • Publication number: 20020076622
    Abstract: A structure and method are provided for correcting the optical proximity effects on a tri-tone attenuated phase-shifting mask. An attenuated rim, formed by an opaque region and an attenuated phase-shifting region, can be kept at a predetermined width across the mask or for certain types of structures. Typically, the attenuated rim is made as large as possible to maximize the effect of the attenuated phase-shifting region while still preventing the printing of larger portions of the attenuated phase-shifting region during the development process.
    Type: Application
    Filed: December 20, 2000
    Publication date: June 20, 2002
    Inventors: Christophe Pierrat, Youping Zhang
  • Patent number: 6404481
    Abstract: Techniques are disclosed to compensate for distortions in lithography by locally heating the membrane in a lithographic mask. The techniques may be used both to shrink and to expand areas of the mask locally, in order to adjust for varying magnitudes and signs of distortion. In one embodiment the correction method comprises two steps: (1) A send-ahead wafer is exposed and measured by conventional means to determine the overlay errors at several points throughout the field. (2) During exposure of subsequent wafers, calibrated beams of light are focused on the mask. The heating from the absorbed light produces displacements that compensate for the overlay errors measured with the send-ahead wafer. Any source of distortion may be corrected—for example, distortion appearing on the mask initially, distortion that only develops on the mask over time, or distortion on the wafer.
    Type: Grant
    Filed: May 25, 2000
    Date of Patent: June 11, 2002
    Assignees: Board of Supervisors of Louisiana State University and Agricultural and Mechanical College, Massachusetts Institute of Technology
    Inventors: Martin Feldman, Henry I. Smith, Ken-Ichi Murooka, Michael H. Lim
  • Patent number: 6396068
    Abstract: An illumination system includes several discharge sources that are multiplexed together to reduce the amount of debris generated.
    Type: Grant
    Filed: October 2, 2000
    Date of Patent: May 28, 2002
    Assignee: EUV LLC
    Inventors: William C. Sweatt, Glenn D. Kubiak
  • Patent number: 6393604
    Abstract: Plural patterns of cell projections made in an aperture are stored in a register. Cells in designed data are compared with the cell projections stored in the register by an interlayer operation, to judge whether or not a cell which coincides with any one of the cells in the designed data is present among the patterns of the cell projections stored in the register. In the case that the judgement that the coinciding cell is present is given, the coinciding cell projection is e acted and outputted as data for direct-writing. In the case that the judgement that no coinciding cell is present is given, if a cell whose reference frequency is over a given value is present, this cell is extracted and registered as a new cell projection.
    Type: Grant
    Filed: November 8, 1999
    Date of Patent: May 21, 2002
    Assignee: NEC Corporation
    Inventors: Yasuhisa Yamada, Yuzo Ogawa
  • Patent number: 6387572
    Abstract: A substrate for reflective EUV lithography that includes a first layer that has a low coefficient of thermal expansion and a second layer, formed on the first layer, that has a high surface quality. The second layer may have a coefficient of thermal expansion that is higher than the coefficient of thermal expansion of the first layer.
    Type: Grant
    Filed: September 13, 1999
    Date of Patent: May 14, 2002
    Assignee: Intel Corporation
    Inventors: Tom X. Tong, Kramadhati V. Ravi
  • Patent number: 6381300
    Abstract: A mask of certain type has a transparent base and a transparent film formed on the transparent base. The transparent film has at least one mask member formed in a predetermined mask pattern and having a relatively low exposure beam transparency. The mask member sometimes has a placement error from a designed placement. This is mainly because an in-plane stress distribution of the transparent film is nonuniformity. The transparent film is partially decreased in thickness to unity the in-plane stress distribution.
    Type: Grant
    Filed: August 31, 2000
    Date of Patent: April 30, 2002
    Assignee: Kabushiki Kaisha Toshiba
    Inventor: Mizunori Ezaki
  • Patent number: 6381005
    Abstract: An exposure device for transferring a pattern on a mask onto a wafer. The exposure device includes a frame for supporting the mask, a mask holding device including a correction mechanism for correcting the pattern on the mask by applying force to the mask frame, and a device for changing at least one of the attitude and position of the correction mechanism, in accordance with the attitude of the mask. The positional relationship between the correction mechanism and the mask does not vary even if the attitude of the mask is changed to adjust the exposure gap between the wafer and the mask. Accordingly, the amount of change in magnification to be corrected can be kept constant and precise magnification correction can be achieved.
    Type: Grant
    Filed: April 28, 1998
    Date of Patent: April 30, 2002
    Assignee: Canon Kabushiki Kaisha
    Inventors: Kazuyuki Kasumi, Takeshi Miyachi
  • Publication number: 20020045109
    Abstract: In a mask for beam exposure, a membrane structure for endless patterns and a stencil structure for terminated patterns are provided in combination.
    Type: Application
    Filed: October 17, 2001
    Publication date: April 18, 2002
    Applicant: NEC Corporation
    Inventor: Yasuhisa Yamada
  • Patent number: 6368942
    Abstract: A method for fabricating masks for extreme ultraviolet lithography (EUVL) using Ultra-Low Expansion (ULE) substrates and crystalline silicon. ULE substrates are required for the necessary thermal management in EUVL mask blanks, and defect detection and classification have been obtained using crystalline silicon substrate materials. Thus, this method provides the advantages for both the ULE substrate and the crystalline silicon in an Extreme Ultra-Violet (EUV) mask blank. The method is carried out by bonding a crystalline silicon wafer or member to a ULE wafer or substrate and thinning the silicon to produce a 5-10 &mgr;m thick crystalline silicon layer on the surface of the ULE substrate. The thinning of the crystalline silicon may be carried out, for example, by chemical mechanical polishing and if necessary or desired, oxidizing the silicon followed by etching to the desired thickness of the silicon.
    Type: Grant
    Filed: March 31, 2000
    Date of Patent: April 9, 2002
    Assignee: EUV LLC
    Inventor: Gregory F. Cardinale
  • Patent number: 6366640
    Abstract: There is disclosed an X-ray mask comprising, on a support substrate 11a, an X-ray transmission film 12 for transmitting X-rays and an X-ray absorber pattern 13a formed on the X-ray transmission film 12 for absorbing the X-rays. The X-ray absorber pattern 13a is formed of a material which contains tantalum, boron, nitrogen and/or oxygen.
    Type: Grant
    Filed: November 12, 1999
    Date of Patent: April 2, 2002
    Assignee: Hoya Corporation
    Inventor: Tsutomu Shoki
  • Patent number: 6366639
    Abstract: In an X-ray exposure method of this invention, an X-ray mask unit in which a patterned X-ray absorber is formed on a membrane is supported. This patterned X-ray absorber contains one of an element having a density/atomic weight of 0.085 [g/cm3] or more and an L-shell absorption edge at a wavelength of 0.75 to 1.6 nm and an element having a density/atomic weight of 0.04 [g/cm3] or more and an M-shell absorption edge at a wavelength of 0.75 to 1.6 nm. Synchrotron radiation having maximum light intensity at a wavelength of 0.6 to 1 nm is applied onto the X-ray mask unit. This improves the exposure accuracy in X-ray exposure.
    Type: Grant
    Filed: June 22, 1999
    Date of Patent: April 2, 2002
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Mizunori Ezaki, Kenichi Murooka
  • Patent number: 6355385
    Abstract: Methods are disclosed for manufacturing reticle blanks, and reticles therefrom, for use in charged-particle-beam microlithography. The subject reticles exhibit substantially less tensile stress and thus substantially less pattern distortion, than conventional reticles. In a representative method, a silicon substrate is provided that includes an active silicon layer and a silicon support portion. At least on the silicon support portion, a wet-etching mask is formed that defines a prescribed pattern of openings corresponding to a desired pattern of windows. The silicon support portion, exposed in the openings, is wet etched depthwise toward the active silicon layer. After completing etching, a protective film of an oxygen-impermeable material is formed over the wet-etched product. The product is annealed, followed by removal of the protective film.
    Type: Grant
    Filed: May 19, 2000
    Date of Patent: March 12, 2002
    Assignee: Nikon Corporation
    Inventor: Shin-ichi Takahashi
  • Patent number: 6355384
    Abstract: A method for fabricating a patterning mask is disclosed in which a membrane layer is deposited on a first surface of a substrate. Patterned and unpatterned portions of the substrate are then defined on a second surface of the substrate. A majority of the thickness of substrate in the unpatterned portions is then dry etched to partially define a strut having sidewalls that are substantially perpendicular to the first surface. Wet etching is then performed to etch through the remaining thickness of the substrate to expose the bottom surface of the membrane layer and completely define the strut. Scattering elements may then be formed over the membrane layer. In one embodiment, the substrate is silicon and has a (110) orientation and an edge of the silicon struts is aligned to a {111} plane. In another embodiment, an edge of the silicon struts is aligned to a {221} plane.
    Type: Grant
    Filed: March 6, 2000
    Date of Patent: March 12, 2002
    Assignee: Motorola, Inc.
    Inventors: William J. Dauksher, Pawitter S. Mangat
  • Publication number: 20020028392
    Abstract: Multilayer film stacks and gray scale processing methods are employed for fabricating phase-shifting masks (PSMs) utilized in lithography. Desired optical transmission and phase-shifting functions of the mask are achieved by controlling the optical properties and thickness of constituent film layers. The mask can be tuned for optimal performance at various wavelengths to an extent beyond that obtainable using a single layer film to control both attenuation and phase shifting of incident light. The processing methods exploit multi-level electron beam or optical beam lithography techniques, and the etch selectivity afforded by selection of appropriate materials for the film stack, to obtain improved yields and reduced processing costs for fabrication of PSMs. In particular, diamond-like carbon (DLC) materials formed by ion beam deposition and having a stress of 1 GPa or less are utilized as etch stop layers.
    Type: Application
    Filed: March 12, 2001
    Publication date: March 7, 2002
    Inventors: Michael Jin, Sing Lee, James Reynolds
  • Publication number: 20020025019
    Abstract: An exposure method for exposing a workpiece in a proximity exposure system, includes a first exposure step for printing, by exposure, an image of a first mask pattern on a predetermined portion of the workpiece, and a second exposure step for printing, by exposure, an image of a second mask pattern, different from the first mask pattern, on the predetermined portion of the workpiece, wherein exposures in the first and second exposure steps are performed superposedly, prior to a development process.
    Type: Application
    Filed: October 18, 2001
    Publication date: February 28, 2002
    Inventors: Mitsuaki Amemiya, Shunichi Uzawa
  • Patent number: 6351515
    Abstract: A membrane mask for use in an electron beam lighography or X-ray lighography has a membrane film formed on a silicon wafer, and a mask body pattern formed on the membrane film. The membrane film has a heavy-metal-implanted area underlying a portion of the mask body pattern other than the opening of the mask body pattern. The implanted area achieves a higher contrast ratio in the pattern obtained from the membrane mask.
    Type: Grant
    Filed: April 18, 2001
    Date of Patent: February 26, 2002
    Assignee: NEC Corporation
    Inventor: Fumihiro Koba
  • Publication number: 20020021781
    Abstract: An X-ray mask has a mask pattern, a protection means for forming a dust-proof space for protecting the mask pattern, and an inner atmospheric pressure adjustment hole for ventilating between the dust-proof space and the outer atmosphere. The X-ray mask can be either a transmission type mask in which the mask pattern is formed on a membrane, or a reflection type mask in which a multilayered film reflection layer and the mask pattern are formed on a substrate.
    Type: Application
    Filed: October 5, 2001
    Publication date: February 21, 2002
    Inventors: Keiko Chiba, Masami Tsukamoto, Yutaka Watanabe, Shinichi Hara, Hiroshi Maehara
  • Publication number: 20020006180
    Abstract: An X-ray projection exposure apparatus includes a mask chuck, a wafer chuck, an X-ray illuminating system, and an X-ray projection system. The masks chuck holds a reflection X-ray mask having a mask pattern thereon. The wafer chuck holds a wafer onto which the mask pattern is transferred. The X-ray illuminating system illuminates the reflection X-ray mask, held by the mask chuck, with X-rays. The X-ray projection optical system projects the mask pattern of the reflection X-ray mask onto the wafer held by the wafer chuck with a predetermined magnification. The mask chuck includes a mechanism for generating static electricity for attracting and holding the reflection X-ray mask by an electrostatic force. The invention also includes a device manufacturing method using such an X-ray projection exposure apparatus to transfer a mask pattern onto the wafer using the X-ray projection exposure apparatus.
    Type: Application
    Filed: September 7, 2001
    Publication date: January 17, 2002
    Inventors: Shinichi Hara, Masami Tsukamoto
  • Patent number: 6333961
    Abstract: Reflection masks are disclosed for use in microlithography (especially soft-X-ray microlithography) in which the linewidth of a circuit pattern defined by such a mask is transferred onto a wafer with reduced adverse effects from reflectance non-uniformities of the mask. A representative reflection mask includes a multilayer mirror that reflects soft X-rays of a prescribed wavelength and a soft-X-ray-absorber layer defining pattern elements. The multilayer mirror is configured to have a thickness period that varies through the thickness dimension of the multilayer mirror.
    Type: Grant
    Filed: August 9, 2000
    Date of Patent: December 25, 2001
    Assignee: Nikon Corporation
    Inventor: Katsuhiko Murakami
  • Patent number: 6334209
    Abstract: Disclosed is an exposure mask inspecting method for use in manufacturing semiconductor devices. This inspecting method calculate gradients of a correlation curve of a variation in critical dimension of an exposure mask and a variation in critical dimension of a resist, extracts portions having large slopes of the correlation curve, and slopes the portions having large slopes of the correlation curve as to-be-measured portions at the time of verifying the specifications of the surface critical dimension of the exposure mask.
    Type: Grant
    Filed: September 2, 1999
    Date of Patent: December 25, 2001
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Koji Hashimoto, Shigeki Nojima
  • Publication number: 20010051304
    Abstract: A reflective mask having non-reflective and reflective regions. The reflective regions are reflective of light at an inspection wavelength and a semiconductor processing wavelength and the non-reflective regions are substantially non-reflective of light at the inspection wavelength and the semiconductor processing wavelength. The contrast of reflected light off of the non-reflective and reflective regions is greater than 0.210 at either of the two wavelengths.
    Type: Application
    Filed: July 5, 2001
    Publication date: December 13, 2001
    Inventors: Alan R. Stivers, Edita Tejnil
  • Patent number: 6327332
    Abstract: An exposure method for posing a workpiece in a proximity exposure system, includes a first exposure step for printing, by exposure, an image of a first mask pattern on a predetermined portion of the workpiece, and a second exposure step for printing, by exposure, an image of a second mask pattern, different from the first mask pattern, on the predetermined portion of the workpiece, wherein exposures in the first and second exposure steps are performed superposedly, prior to a development process.
    Type: Grant
    Filed: October 22, 1999
    Date of Patent: December 4, 2001
    Assignee: Canon Kabushiki Kaisha
    Inventors: Mitsuaki Amemiya, Shunichi Uzawa
  • Patent number: 6324250
    Abstract: An exposure method for transferring a pattern of a mask onto a workpiece in a proximity exposure system, includes a first exposure step for exposing a predetermined portion of the workpiece, while maintaining a first spacing between the mask and the workpiece, and a second exposure step for exposing the predetermined portion of the workpiece, while maintaining a second spacing, different from the first spacing, between the mask and the workpiece, wherein exposures in the first and second exposure steps are performed superposedly, prior to a development process.
    Type: Grant
    Filed: October 22, 1999
    Date of Patent: November 27, 2001
    Assignee: Canon Kabushiki Kaisha
    Inventors: Mitsuaki Amemiya, Shunichi Uzawa, Yutaka Watanabe
  • Patent number: 6319635
    Abstract: A multilayer film is used as a buffer layer to minimize the size of defects on a reticle substrate prior to deposition of a reflective coating on the substrate. The multilayer buffer layer deposited intermediate the reticle substrate and the reflective coating produces a smoothing of small particles and other defects on the reticle substrate. The reduction in defect size is controlled by surface relaxation during the buffer layer growth process and by the degree of intermixing and volume contraction of the materials at the multilayer interfaces. The buffer layers are deposited at near-normal incidence via a low particulate ion beam sputtering process. The growth surface of the buffer layer may also be heated by a secondary ion source to increase the degree of intermixing and improve the mitigation of defects.
    Type: Grant
    Filed: December 6, 1999
    Date of Patent: November 20, 2001
    Assignee: The Regents of the University of California
    Inventors: Paul B. Mirkarimi, Sasa Bajt, Daniel G. Stearns
  • Patent number: 6319636
    Abstract: A cell projection mask, comprising: a frame for supporting means; a membrane formed over the frame, for making a stress due to electron beam to maintain balance; and an absorber formed over the membrane, for absorbing or reflecting the electron beam, wherein the absorber is comprised of a silicon layer and includes at least one or more ion implanting layers.
    Type: Grant
    Filed: December 23, 1999
    Date of Patent: November 20, 2001
    Assignee: Hyundai Electronics Industries Co., Ltd.
    Inventor: Young Mog Ham
  • Patent number: 6317480
    Abstract: An X-ray mask including a mask support formed into the shape of a frame, an X-ray-transparent film which is supported so as to extend over the surface of the frame-shaped mask support and which permits transmission of X-rays, and a desired X-ray-absorbing film pattern laid on the X-ray-transparent film, wherein the mask support has a thickness which by itself affords sufficient mechanical strength; and a step is formed along the periphery of the mask support.
    Type: Grant
    Filed: April 23, 1999
    Date of Patent: November 13, 2001
    Assignee: Hoya Corporation
    Inventors: Tsutomu Shoki, Akinori Kurikawa, Takamitsu Kawahara, Ryo Ohkubo
  • Patent number: 6317866
    Abstract: In a charged particle beam drawing data preparing method of preparing drawing pattern data used in a charged particle beam drawing apparatus that forms a micropattern with a charged particle by converting CAD data, it is verified by using interlayer calculation whether a difference exists between the CAD data and the drawing pattern data. When it is verified that a difference exists between the CAD data and the drawing apparatus pattern data, drawing pattern data that compensates for this difference is generated by using interlayer calculation.
    Type: Grant
    Filed: August 19, 1998
    Date of Patent: November 13, 2001
    Assignee: NEC Corporation
    Inventor: Takao Tamura
  • Patent number: 6317479
    Abstract: An X-ray mask includes a mask pattern formed on a surface, a detachable protection cover attached on the surface for forming a dust-proof space for protecting the mask pattern, the protection cover being detached when the mask pattern is exposed with X-rays, and a hole for ventilating between the dust-proof space and an outer atmosphere.
    Type: Grant
    Filed: May 16, 1997
    Date of Patent: November 13, 2001
    Assignee: Canon Kabushiki Kaisha
    Inventors: Keiko Chiba, Masami Tsukamoto, Yutaka Watanabe, Shinichi Hara, Hiroshi Maehara
  • Patent number: 6316150
    Abstract: Thermal distortion of reticles or masks can be significantly reduced by emissivity engineering, i.e., the selective placement or omission of coatings on the reticle. Reflective reticles so fabricated exhibit enhanced heat transfer thereby reducing the level of thermal distortion and ultimately improving the quality of the transcription of the reticle pattern onto the wafer. Reflective reticles include a substrate having an active region that defines the mask pattern and non-active region(s) that are characterized by a surface that has a higher emissivity than that of the active region. The non-active regions are not coated with the radiation reflective material.
    Type: Grant
    Filed: August 24, 1998
    Date of Patent: November 13, 2001
    Assignee: EUV LLC
    Inventors: Steven E. Gianoulakis, Avijit K. Ray-Chaudhuri
  • Publication number: 20010038950
    Abstract: A mask structure to be used for X-ray exposure or the like in manufacturing semiconductor devices prevents contaminants from adhering and accumulating on the surface of a mask, thereby extending the life of the mask. In this mask structure, titanium oxide films are formed on front and back pellicles that protect a mask, composed of a support film and an X-ray absorber, from dust or the like. Titanium oxide decomposes contaminants by functioning as a photocatalyst, and prevents the adhesion and accumulation of contaminants by an antistatic function based on photoconductivity. When a titanium oxide film is formed on the surface of the mask itself, it is preferable that the film be formed outside the exposure area or the like.
    Type: Application
    Filed: September 28, 1998
    Publication date: November 8, 2001
    Applicant: Keiko Chiba
    Inventors: KEIKO CHIBA, HIDEO KATO, HIROSHI MAEHARA
  • Publication number: 20010038953
    Abstract: A reflection-type mask for use in exposing a pattern onto a photosensitive material, wherein the mask includes a reflection area, having a multilayer film, for reflecting exposure light, and a non-reflection area which does not reflect the exposure light, the reflection area and the non-reflection area forming a mask pattern, wherein at least one layer of the multilayer film consists of an impurity semiconductor, whereby bad influences, for example, caused by poor conduction of the multilayer film at mask-production stage, can be prevented.
    Type: Application
    Filed: April 26, 2001
    Publication date: November 8, 2001
    Inventors: Masami Tsukamoto, Keiko Chiba
  • Patent number: 6314554
    Abstract: A method of generating mask pattern data for graphics and an apparatus for the same are provided wherein each line segment as a processing unit for graphic arithmetic processing is stored as data in tree structure evenly divided into two for every partial region obtained by plurally dividing the overall pattern data, and this partial region is formed by equally dividing the pattern data by m in an X axis direction, and among the regions, those which includes line segments intensively are further divided to form data of tree structure evenly divided into two for every divided region.
    Type: Grant
    Filed: January 6, 1999
    Date of Patent: November 6, 2001
    Assignee: Sony Corporation
    Inventor: Ryuji Takenouchi
  • Publication number: 20010033634
    Abstract: A membrane mask for use in an electron beam lighography or X-ray lighography has a membrane film formed on a silicon wafer, and a mask body pattern formed on the membrane film. The membrane film has a heavy-metal-implanted area underlying a portion of the mask body pattern other than the opening of the mask body pattern. The implanted area achieves a higher contrast ratio in the pattern obtained from the membrane mask.
    Type: Application
    Filed: April 18, 2001
    Publication date: October 25, 2001
    Inventor: Fumihiro Koba