Patents by Inventor Barbara J. Sapjeta

Barbara J. Sapjeta 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).

  • Etching of copper-containing devices
    Patent number: 5620558
    Abstract: The linewidth in patterns produced by etching copper layers is more easily maintained using a specific etching medium. In particular, this medium includes aqueous hydrofluoric acid, copper chloride, and an additional chloride salt. The etching medium is also particularly useful for bilayer metal constructions such as the copper/titanium structure found in many multichip modules.
    Type: Grant
    Filed: March 28, 1994
    Date of Patent: April 15, 1997
    Assignee: Lucent Technologies Inc.
    Inventors: Karrie J. Hanson, Barry Miller, Barbara J. Sapjeta, Akshay V. Shah, Ken M. Takahashi
  • Process for etching titanium at a controllable rate
    Patent number: 5376236
    Abstract: A process for removing titanium from a device is disclosed. The titanium is etched at a controllable rate. The etchant oxidizes the titanium, and the oxidized titanium forms a complex in the etchant. When the concentration of this complex in the etchant nears its solubility limit, it precipitates and forms a film on the titanium metal surface. This film reduces the rate of the etch, enabling the amount of titanium removed by the etchant to be controlled.
    Type: Grant
    Filed: October 29, 1993
    Date of Patent: December 27, 1994
    Assignee: AT&T Corp.
    Inventors: Karrie Jo Hanson, Barbara J. Sapjeta, Ken M. Takahashi
  • Etching of copper-containing devices
    Patent number: 5298117
    Abstract: The linewidth in patterns produced by etching copper layers is more easily maintained using a specific etching medium. In particular, this medium includes aqueous hydrofluoric acid, copper chloride, and an additional chloride salt. The etching medium is also particularly useful for bilayer metal constructions such as the copper/titanium structure found in many multichip modules.
    Type: Grant
    Filed: July 19, 1993
    Date of Patent: March 29, 1994
    Assignee: AT&T Bell Laboratories
    Inventors: Karrie J. Hanson, Barry Miller, Barbara J. Sapjeta, Akshay V. Shah, Ken M. Takahashi