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. 01, 2020
Filed:
Feb. 13, 2015
Hitachi, Ltd., Tokyo, JP;
Itaru Yanagi, Tokyo, JP;
Kenichi Takeda, Tokyo, JP;
HITACHI, LTD., Tokyo, JP;
Abstract
A method for producing a membrane device includes: forming an insulating film as a first film on a Si substrate; forming a Si film as a second film on the entire surface or a part of the first film; forming an insulating film as a third film on the second film; forming an aperture so as to pass through a part of the third film positioned on the second film and not to pass through the second film; etching a part of the substrate on one side of the first film with a solution that does not etch the first film; and etching a part or all of the second film on the other side of the first film with a gas or a solution that does not etch the first film and has an etching rate for the third film lower than an etching rate for the second film.