Patents by Inventor Akimori Hiroyuki

Akimori Hiroyuki 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: 4999318
    Abstract: A method for forming vias, interconnecting selected wiring layers of an integrated circuit device, which overcomes oxide formation on the wiring metal surface which is exposed at the etched via bottom before filling the via with interconnecting metal. The method first etches the vias through the insulating layer, with a step or stair like wall formation, to expose the underlying metal surface. The exposed metal surface is then sputter etched to remove the undesired oxide layer which forms on the metal surface at the via bottom after being exposed by the etch through process. During the sputter etch oxide removal process, the stair like via wall prevents re-oxidation of the exposed metal surface by stray silicon oxide particles dislodged from the via wall during the sputter process.
    Type: Grant
    Filed: July 6, 1989
    Date of Patent: March 12, 1991
    Assignee: Hitachi, Ltd.
    Inventors: Tokunaga Takahumi, Tsuneoka Masatoshi, Akimori Hiroyuki, Horiuch Mitsuaki