Patents by Inventor Donald M. Tennant

Donald M. Tennant has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Patent number: 5521031
    Abstract: The operating principle of the attenuated phase mask is incorporated in a reflecting structure for use with extreme ultraviolet radiation. A working projection-reduction system for use with 0.18 .mu.m and smaller features combines the mask with all-reflecting optics.
    Type: Grant
    Filed: October 20, 1994
    Date of Patent: May 28, 1996
    Assignee: AT&T Corp.
    Inventors: Donald M. Tennant, Donald L. White, Obert R. Wood, II
  • Patent number: 5510230
    Abstract: The fabrication of integrated circuit devices built to design rules of 0.18 .mu.m and below uses patterning radiation in the EUV spectrum. Optimized processing conditions take advantage of independently developed EUV characteristics such as short resist absorption lengths.
    Type: Grant
    Filed: October 20, 1994
    Date of Patent: April 23, 1996
    Assignee: AT&T Corp.
    Inventors: Donald M. Tennant, Donald L. White, Obert R. Wood, II
  • Patent number: 5413884
    Abstract: A technique is disclosed for utilizing direct-write electron-beam photolithography and holographic optical exposure to form gratings in optoelectronic structures. The direct-write e-beam process is used to form rectangular grating teeth in a mask substrate, where the mask is then used as a phase mask to transfer the pattern to the optoelectronic device. Advantageously, the utilization of a direct write e-beam technique to form the grating pattern on the photomask allows for the formation of any desired number and location of abrupt phase shifts, multiple grating pitches, alignment fiducials, and any other desired features. Therefore, a single exposure of the direct write e-beam mask allows for a plurality of different grating patterns to be simultaneously printed.
    Type: Grant
    Filed: December 14, 1992
    Date of Patent: May 9, 1995
    Assignee: American Telephone and Telegraph Company
    Inventors: Thomas L. Koch, Frederick W. Ostermayer, Jr., Donald M. Tennant, Jean-Marc Verdiell
  • Patent number: 5356662
    Abstract: The invention in one aspect involves a method for repairing an optical system. The optical system includes at least one optical element which comprises, in turn, a substrate having a principal surface, and a multilayer coating overlying the principal surface. The substrate comprises a first material, and the multilayer coating comprises plural second and at least third material layers in alternation. The method includes the steps of removing the multilayer coating from the substrate, and redepositing a new multilayer coating on the substrate. The old multilayer coating is removed in a single etching step while preserving the quality of the principal surface to such an extent that the peak reflectivity of the new multilayer coating is at least 80% the reflectivity of the old multilayer coating.
    Type: Grant
    Filed: January 5, 1993
    Date of Patent: October 18, 1994
    Assignee: AT&T Bell Laboratories
    Inventors: Kathleen R. Early, Donald M. Tennant, Warren K. Waskiewicz, David L. Windt
  • Patent number: 5304437
    Abstract: Fabrication of reflective masks, designed for use with x-ray delineating radiation in the construction of sub-micron devices, is expedited by use of a barrier layer intermediate the multilayer reflector and the absorber layer. The barrier is designed to reduce damage to the multilayer reflector during two stages of fabrication--during initial patterning and during subtractive or additive mask repair. Composition of the barrier is so chosen as to minimize such damage during its removal in baring of the reflector, and also as to have requisite stability in regions retained during mask life.
    Type: Grant
    Filed: April 3, 1992
    Date of Patent: April 19, 1994
    Assignee: AT&T Bell Laboratories
    Inventor: Donald M. Tennant
  • Patent number: 5265143
    Abstract: In one aspect, the invention involves an optical element in an x-ray imaging system. The element comprises a substrate overlain by a multilayer coating. The multilayer coating comprises plural first and at least second material layers in alternation. This coating is soluble in at least one etchant solution at an etching temperature less than 100.degree. C. The optical element further comprises a barrier layer intermediate the substrate and the multilayer coating. The barrier layer is relatively insoluble in the etchant solution at the etching temperature. In a second aspect of the invention, the optical element comprises a substrate and a multilayer coating as described above, and further comprises a release layer that underlies the multilayer coating. The release layer comprises a material that is relatively soluble in at least one etchant solution at an etching temperature less than 100.degree. C. In contrast to release layers of the prior art, the inventive release layer comprises germanium.
    Type: Grant
    Filed: January 5, 1993
    Date of Patent: November 23, 1993
    Assignee: AT&T Bell Laboratories
    Inventors: Kathleen R. Early, Richard E. Howard, Donald M. Tennant, Warren K. Waskiewicz, David L. Windt
  • Patent number: 4344816
    Abstract: Bodies having conical structures with dimensions on the order of the wavelength of visible light are prepared by a specific process. This process involves the formation of a mask by depositing a material that forms the mask onto the body to be etched and choosing the mask material so that it does not substantially wet the surface of the body. The mask thus fabricated has hill-type formations where the spacings between these formations are of the order of the wavelength of visible light. An etchant that etches the mask at a specific rate relative to the underlying body is then used to perform the etching procedure. Exemplary bodies produced by the procedure include tungsten textured bodies that exhibit light emissivities significantly higher than those possessed by the corresponding untreated tungsten material.
    Type: Grant
    Filed: December 19, 1980
    Date of Patent: August 17, 1982
    Assignee: Bell Telephone Laboratories, Incorporated
    Inventors: Harold G. Craighead, Richard E. Howard, Donald M. Tennant