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:
Sep. 08, 1998
Filed:
Mar. 18, 1996
Yasukazu Iwasaki, Yokosuka, JP;
Norihiko Kiritani, Yokosuka, JP;
Makiko Mitamura, Fujisawa, JP;
Takatoshi Noguchi, Yokosuka, JP;
Makoto Uchiyama, Miura, JP;
Nissan Motor Co., Ltd., Yokohama, JP;
Abstract
An etching process for a silicon semiconductor substrate to produce a semiconductor pressure sensor or a semiconductor acceleration sensor. The etching process comprises the following steps: (a) carrying out an etching of the semiconductor without application of a voltage to the semiconductor so as to accomplish a pre-etching step, the pre-etching step including dipping the semiconductor in hydrazine hydrate; and (b) carrying out an electrochemical etching of the semiconductor by applying pre-etching step so as to accomplish a final etching step, the final etching step including dipping the semiconductor in an alkali system etching solution containing at least hydrazine (N.sub.2 H.sub.4), potassium hydroxide (KOH), and water (H.sub.2 O), the alkali system etching solution containing potassium hydroxide in an amount of not less than 0.3% by weight.