The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Dec. 01, 1992
Filed:
Aug. 05, 1991
Hiroyuki Kaneko, Yokohama, JP;
Makoto Uchiyama, Zushi, JP;
Hidetoshi Nojiri, Yokosuka, JP;
Norihiko Kiritani, Yokosuka, JP;
Nissan Motor Co., Ltd., Yokahama, JP;
Abstract
An electrochemical etching method for producing semiconductor diaphragms from a semiconductor wafer comprised of a first semiconductor layer of a first conductivity type and a second semiconductor layer formed on the first semiconductor layer, the second semiconductor layer having a second conductivity type different than the first semiconductor layer. The semiconductor wafer is placed in an etching solution with respect to a counter-electrode immersed in the etching solution. The semiconductor wafer has a plurality of chips each of which includes at least one third semiconductor layer of the first conductivity type. The third semiconductor layer extends through the second semiconductor layer to the first semiconductor layer. A first positive potential is applied to the first and third semiconductor layers with respect to the counter-electrode. A second positive potential is applied to the second semiconductor layer with respect to the first semiconductor layer.