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:
Jul. 22, 1997
Filed:
May. 25, 1995
Kazutoshi Kaji, Taihaku-ku, Sendai-shi, 982, JP;
Shueh Lin Yau, Sendai, JP;
Kingo Itaya, Sendai, JP;
Toshihiko Sakuhara, Sendai-shi, Miyagi-ken, 982, JP;
Research Development Corporation of Japan, Saitama-ken, JP;
Other;
Abstract
A silicon substrate is etched by dipping it in a NH.sub.4 F solution while charging it with a potential more negative than an open-circuit potential. The NH.sub.4 F solution preferably has NH.sub.4 F concentration of 10M or less. The potential applied to the silicon substrate is controlled within the range of from the open-circuit potential to a more negative potential by -1.5 V vs. SCE. Since the etched silicon substrate has flatness in atomic order, it is suitable for the precise fabrications to manufacture high-density ir high-functional semiconductor devices.