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:
Mar. 11, 2003
Filed:
Feb. 21, 2001
Kazuyoshi Yoshida, Tokyo, JP;
Nobuyuki Ikezawa, Tokyo, JP;
NEC Corporation, Tokyo, JP;
Abstract
A method for fabricating a semiconductor device including the steps of: sequentially forming an oxide film and a polycrystalline silicon film overlying a substrate; and selectively dry-etching the polycrystalline silicon film in consecutive two processes including a main etching process for dry-etching the polycrystalline silicon film under existence of Cl , HBr and CF and an over-etching process for dry-etching the polycrystalline silicon film under existence of HBr and oxygen. In the process, the polycrystalline silicon film is etched in the main etching process with the excellent dimension controllability and is etched in the over etching process with the higher selective ratio between the polycrystalline silicon film and the gate oxide film.