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:
Jan. 19, 2016
Filed:
Oct. 28, 2011
Tadahiro Ohmi, Sendai, JP;
Tomotsugu Ohashi, Singapore, SG;
Kazuhiro Yoshikawa, Inashiki-gun, JP;
Tatsuro Yoshida, Sendai-shi, JP;
Teppei Uchimura, Hamamatsu, JP;
Kazuki Soeda, Hamamatsu, JP;
Shigetoshi Sugawa, Sendai, JP;
Tadahiro Ohmi, Sendai, JP;
Tomotsugu Ohashi, Singapore, SG;
Kazuhiro Yoshikawa, Inashiki-gun, JP;
Tatsuro Yoshida, Sendai-shi, JP;
Teppei Uchimura, Hamamatsu, JP;
Kazuki Soeda, Hamamatsu, JP;
Shigetoshi Sugawa, Sendai, JP;
TOHOKU UNIVERSITY, Miyagi, JP;
Abstract
A method of etching capable of rapidly and flatly performing wet etching on a Si substrate using fluonitric acid represented by HF(a)HNO(b)HO(c) (where the unit of a, b and c is wt % and a+b+c=100). The etching rate of an SiOlayer with the highly concentrated fluonitric acid is significantly lowered by the appropriate selection of its composition as compared with the etching rate of the Si substrate, and etch the Si substrate until the SiOlayer is exposed. In this way, it is possible to rapidly etch the Si substrate and significantly enhance the flatness of the etched surface.