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:
Jun. 09, 1987
Filed:
Jan. 25, 1985
Kazuji Yamada, Hitachi, JP;
Yutaka Kobayashi, Hitachi, JP;
Kanji Kawakami, Mito, JP;
Satoshi Shimada, Hitachi, JP;
Masanori Tanabe, Hitachi, JP;
Shigeyuki Kobori, Hitachi, JP;
Hitachi, Ltd., Tokyo, JP;
Abstract
A method of making a silicon diaphragm pressure sensor includes forming an oxide film on one surface of a monocrystalline silicon substrate. A polycrystalline silicon layer is formed on the oxide film. The oxide film may be partly removed before the formation of the polycrystalline silicon layer. The polycrystalline silicon layer is heated and melt to recrystallize the same, thereby converting the polycrystalline silicon layer into a monocrystalline silicon layer. On the monocrystalline silicon layer may be epitaxially grown an additional monocrystalline silicon layer. By using the oxide film as an etching stopper, a predetermined portion of the substrate is etched over a range from the other surface of the substrate to the oxide film, thereby providing a diaphragm of the pressure sensor.