Patents by Inventor A. L. Shields

A. L. Shields 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).

  • Metal etch solution and method
    Patent number: 4345969
    Abstract: A solution is disclosed for the one-step etching of a three layer titanium-nickel-copper metallization. The etch solution comprises about 1.8 to 2.0 moles/liter hydrofluoric acid, about 2.5 to 4.0 moles/liter acetic acid, about 8.7 to 9.0 moles/liter nitric acid, and balance water. Use of the solution permits the patterned etching of sequential layers of titanium, nickel, and copper without excessive attack of underlying silicon dioxide layers.
    Type: Grant
    Filed: March 23, 1981
    Date of Patent: August 24, 1982
    Assignee: Motorola, Inc.
    Inventors: Kristi L. James, A. L. Shields