Patents by Inventor Frances P. Alvarez

Frances P. Alvarez 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: 5077234
    Abstract: A planarization method utilizing three resist layers is disclosed. In a substrate where the surface geometry contains trenches or steps of constant height separated by varying distances, after a CVD oxidation layer is formed, a first resist layer (plugs) is formed in wide trenches. A second resist layer is formed on the substrate to provide a gross global planarization of the substrate, which is etched back until all of the resist is removed from the active areas. A third resist layer is then formed on the substrate to provide a near planar surface. All of the resist and CVD oxide is removed from the active areas.
    Type: Grant
    Filed: June 29, 1990
    Date of Patent: December 31, 1991
    Assignee: Digital Equipment Corporation
    Inventors: John P. Scoopo, Frances P. Alvarez, Gregory J. Grula