Patents by Inventor Eric V. Johnstone

Eric V. Johnstone 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).

  • Multi-tone photomask and method for manufacturing the same
    Patent number: 6803160
    Abstract: A multi-tone photomask and method for manufacturing the same are disclosed. A photomask includes a filter layer formed on at least a portion of a substrate. The filter layer includes a first pattern formed by a first etch process. A barrier layer including the first pattern is formed on at least a portion of the filter layer by a second etch process. An absorber layer including a second pattern is formed on at least a portion of the barrier layer by a third etch process. The barrier layer further acts as an etch stop for the third etch process.
    Type: Grant
    Filed: December 12, 2002
    Date of Patent: October 12, 2004
    Assignee: DuPont Photomasks, Inc.
    Inventors: Eric V. Johnstone, Franklin D. Kalk
  • Multi-tone photomask and method for manufacturing the same
    Publication number: 20030118920
    Abstract: A multi-tone photomask and method for manufacturing the same are disclosed. A photomask includes a filter layer formed on at least a portion of a substrate. The filter layer includes a first pattern formed by a first etch process. A barrier layer including the first pattern is formed on at least a portion of the filter layer by a second etch process. An absorber layer including a second pattern is formed on at least a portion of the barrier layer by a third etch process. The barrier layer further acts as an etch stop for the third etch process.
    Type: Application
    Filed: December 12, 2002
    Publication date: June 26, 2003
    Applicant: DuPont Photomasks, Inc.
    Inventors: Eric V. Johnstone, Franklin D. Kalk