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. 13, 2001
Filed:
Mar. 31, 1998
Applicant:
Inventor:
Akira Mitsuiki, Tokyo, JP;
Assignee:
NEC Corporation, Tokyo, JP;
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
H01L 2/1302 ;
U.S. Cl.
CPC ...
H01L 2/1302 ;
Abstract
In the process of simultaneously etching a polysilicon layer in a groove of a memory cell section and a polysilicon layer in a peripheral circuit section, a Cl,/HBr-based gas is used as a first etching step, and this etching is performed until polysilicon in the peripheral section is removed. Next, the gas is switched to a C1,/HBr/O,-based gas to remove an etched particulate resist film having accumulated in the groove. As a final step, the polysilicon layer remaining in the groove is etched with a HBr/O,-based gas having a high selectivity ratio against an oxide film.