Patents by Inventor Alan C. Thomas

Alan C. Thomas 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).

  • Publication number: 20030098644
    Abstract: Particles of electroluminescent phosphor having a moisture proof coating are re-coated by treating the phosphor in a fluidized bed with a mixture of water vapor and an organotrichlorosilane compound for approximately thirty minutes. The resultant siloxane coating further improves the moisture resistance of the phosphor.
    Type: Application
    Filed: November 13, 2001
    Publication date: May 29, 2003
    Inventor: Alan C. Thomas
  • Publication number: 20030071574
    Abstract: At least one layer of cascading material overlying an EL lamp converts the light emitted by the EL lamp into infrared light. The EL lamp is supported within in a container transparent to at least infrared light, along with at least one battery and an inverter to provide power for the lamp in portable applications. The lamp is rolled to form a cylinder and fits within the inside diameter of the container. The lamp can be turned on or off by means of a switch interrupting current from a battery or to the lamp.
    Type: Application
    Filed: October 9, 2001
    Publication date: April 17, 2003
    Applicant: Durel Corporation
    Inventors: Charles I. Zovko, Alan C. Thomas
  • Publication number: 20020133800
    Abstract: A method for employing a plurality of reusable reticles in an integrated circuit manufacturing process employing lithographic exposure of a semiconductor wafer. Initially there is provided a matrix of a plurality of reticles, each matrix comprising a plurality of tuples of reticles, each reticle tuple comprising one or more reticles. The method then includes defining at least one set of valid groups of reticles in the matrix for use in a desired lithographic exposure process, defining a set of conditions for determining availability of all reticles in the valid groups in the lithographic exposure process, and comparing the availability conditions to the reticles in the set of valid groups and eliminating valid groups which do not meet the availability conditions, leaving non-eliminated valid groups.
    Type: Application
    Filed: January 16, 2001
    Publication date: September 19, 2002
    Applicant: International Business Machines Corporation
    Inventors: John T. Federico, Perry G. Hartswick, Alan C. Thomas
  • Patent number: 6451508
    Abstract: A method for exposing a workpiece in a dual exposure step-and-repeat process starts by forming a design for a reticle mask. Deconstruct the design for the reticle mask by removing a set(s) of the features that are juxtaposed. Form unexposed resist on the workpiece. Load the workpiece and the reticle mask into the stepper. Expose the workpiece through the reticle mask. Reposition the workpiece by a nanostep. Then expose the workpiece through the reticle mask after the repositioning. Test whether the plural exposure process is finished. If the result of the test is NO the process loops back to repeat some of the above steps. Otherwise the process has been completed. An overlay mark is produced by plural exposures of a single mark. A dead zone is provided surrounding an array region in which printing occurs subsequent to exposure in an original exposure. Stepper-framing-blades are moved over the dead zone to prevent additional exposures after an initial exposure.
    Type: Grant
    Filed: April 28, 2000
    Date of Patent: September 17, 2002
    Assignees: International Business Machines Corporation, Infineon Technologies North America Corp.
    Inventors: Scott J. Bukofsky, Gerhard Kunkel, Alan C. Thomas
  • Patent number: 6436585
    Abstract: A method of making a photolithography mask for use in creating an electrical fuse on a semiconductor structure comprises initially determining a pattern for a desired electrical fuse, with the pattern including a fuse portion of substantially constant width except for a localized narrowed region of the fuse portion at which the electrical fuse is designed to blow. The method then includes providing a photolithography mask substrate and creating on the photolithography mask substrate a fuse mask element adapted to absorb transmission of an energy beam. The fuse mask element has a first mask portion of substantially constant width corresponding to the desired electrical fuse pattern portion of substantially constant width, and a second mask portion corresponding to the localized narrowed region of the fuse portion. The second mask portion comprises either an additional mask element spaced from the first mask portion, a narrowed width portion, or a gap in the first mask portion.
    Type: Grant
    Filed: February 25, 2000
    Date of Patent: August 20, 2002
    Assignees: International Business Machines Corporation, Infineon Technologies North America Corp.
    Inventors: Chandrasekhar Narayan, Axel Brintzinger, Fred L. Einspruch, Henning Haffner, Alan C. Thomas
  • Patent number: 6427090
    Abstract: A system is provided for controlling the time at which a durable item, such as a reticle used in a lithography process in semiconductor manufacturing, is requalified for use. A counting device counts occurrences of predefined events, such as the number of jobs in which the reticle is used or the number of times it is placed in a lithography tool. The reticle is not removed from use until a limiting number of jobs or tool placements is reached, or the reticle is needed for processing the requalification job. The system also includes a requalification device for the durable item.
    Type: Grant
    Filed: August 18, 1999
    Date of Patent: July 30, 2002
    Assignee: International Business Machines Corporation
    Inventors: John T. Federico, Perry G. Hartswick, Alan C. Thomas, Anne Marie Pelella
  • Patent number: 6303275
    Abstract: A method of forming a resist layer of uniform thickness across a surface patterned with a varying density of high aspect ratio features. A selected material layer having an affinity to a resist coat to be applied over the selected material layer is applied to a wafer having a plurality of recesses before applying a resist coat. After the resist coat is applied over the selected material layer, the selected material diffuses partially into the resist coat to condition a portion of the resist coat to be insoluble in the presence of a developer which is applied after the resist coat. Those portions of the resist coat into which the selected material layer has not diffused then are removed by a developer leaving a uniform resist coat thickness across the wafer.
    Type: Grant
    Filed: February 10, 2000
    Date of Patent: October 16, 2001
    Assignee: International Business Machines Corporation
    Inventors: Robert A. Coles, John W. Golz, Qinghuang Lin, Alan C. Thomas, Christopher J. Waskiewicz, Teresa J. Wu
  • Patent number: 6268907
    Abstract: The present invention provides a method and an optical lithographic system which eliminates the standing wave effect typically observed in photoresists without the need for altering the thickness of the photoresist, utilizing an anti-reflective coating material, or changing the light source. Specifically, the present invention compensates for standing waves by exposing the photoresist with light from a light source at different phases. That is, in the present invention there is a change in light exposure from a single dose at one phase to a plurality of doses at different phases; therefore dispersing the effects of the standing wave at each of those phases which in turn eliminates the standing wave.
    Type: Grant
    Filed: May 13, 1998
    Date of Patent: July 31, 2001
    Assignee: International Business Machines Corporation
    Inventors: Donald J. Samuels, Alan C. Thomas
  • Patent number: 5953128
    Abstract: Focus and exposure parameters may be controlled in a lithographic process for manufacturing microelectronics by creating a complementary tone pattern of shapes and spaces in a resist film on a substrate. Corresponding dimensions of the resist shape and space are measured and the adequacy of focus or exposure dose are determined as a function of the measured dimensions. Etching parameters may also be controlled by creating a complementary tone pattern of etched shapes and spaces on a substrate. Corresponding dimensions of the etched shape and space are measured and the adequacy of etching parameters are determined as a function of the measured dimensions.
    Type: Grant
    Filed: August 28, 1997
    Date of Patent: September 14, 1999
    Assignee: International Business Machines Corporation
    Inventors: Christopher P. Ausschnitt, Timothy A. Brunner, Alan C. Thomas
  • Patent number: 5618751
    Abstract: A trench capacitor with a buried plate is formed with a single etching process by the expedient of filling the trench so formed and lined with diffusion source material with resist by baking and reflowing the resist which also serves to adjust exposure sensitivity of the resist such that exposure and development of the resist removes the resist to a repeatable and uniform depth. Remaining resist allows etching of the diffusion source layer to a very accurate dimension. Thus only a readily formed oxide or TECS layer is needed to confine impurities during diffusion to form the buried plate. An isolation collar can be formed after recess of the fill to avoid formation of step corners and erosion of the isolation collar by repeated fill and etch back processes while permitting maximum capacitance to be achieved for a given trench "footprint".
    Type: Grant
    Filed: May 23, 1996
    Date of Patent: April 8, 1997
    Assignee: International Business Machines Corporation
    Inventors: Kevin M. Golden, Pai-Hung Pan, Kevin J. Stewart, Alan C. Thomas
  • Patent number: 4853594
    Abstract: An electroluminescent lamp including a phosphor layer disposed between corresponding lamp electrodes that are adapted to apply an excitation potential to cause the phosphor layer to emit light, the front lamp electrode being light-transmsisive to radiation from the phosphor layer, has an improved front lamp electrode consisting of a thin layer of light-transmissive binder containing a distribution of discrete gallium-doped zinc oxide particles. A method of forming the lamp is also described.
    Type: Grant
    Filed: August 10, 1988
    Date of Patent: August 1, 1989
    Assignee: Rogers Corporation
    Inventor: Alan C. Thomas