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:
May. 19, 2015
Filed:
Jul. 18, 2013
Tokyo Electron Limited, Tokyo, JP;
Koji Maruyama, Miyagi, JP;
Mikio Yamamoto, Miyagi, JP;
TOKYO ELECTRON LIMITED, Tokyo, JP;
Abstract
A method of etching a substrate by plasma via a mask having a predetermined pattern at back of a silicon layer of the substrate, a semiconductor device being formed at front of which supported by a support substrate, includes a main etching step in which plasma is generated by supplying a process gas including a mixed gas whose flow ratio of fluorine compound gas, oxygen gas and silicon fluoride gas is 2:1:1.5 or a process gas including a mixed gas in which at least the ratio of one of the oxygen gas and the silicon fluoride gas, using the fluorine compound gas as a standard, is larger than the above ratio, and the substrate is etched by the plasma; and an over etching step in which the substrate is further etched by plasma while applying a high frequency for bias whose frequency is less than or equal to 400 kHz.