Patents by Inventor Rita Prasad Subrahmanyan

Rita Prasad Subrahmanyan 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).

  • Carboxylic acid etching solution and method
    Patent number: 5824601
    Abstract: A sacrificial oxide etching solution of carboxylic acid and HF having a high etch selectivity for silicon oxide relative to polysilicon, metal, and nitride. The solution is useful in the fabrication of microstructures having integrated electronics on the same chip. A carboxylic acid anhydride can be added to this solution to substantially remove all free water so that the etch selectivity to metal is improved. One specific solution is formed by mixing acetic acid, acetic anhydride, and aqueous HF.
    Type: Grant
    Filed: June 30, 1997
    Date of Patent: October 20, 1998
    Assignee: Motorola, Inc.
    Inventors: Patrick P. H. Dao, Paul William Dryer, Ping-Chang Lue, Michael J. Davison, Terry Andrew Willett, Margaret Leslie Kniffin, Rita Prasad Subrahmanyan