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:
Nov. 25, 2014
Filed:
Oct. 19, 2011
Applicant:
Stefan Detterbeck, Villach, AT;
Inventor:
Stefan Detterbeck, Villach, AT;
Assignee:
Lam Research AG, Villach, AT;
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
C09K 13/00 (2006.01); C09K 13/04 (2006.01); C09K 13/08 (2006.01); C03C 15/00 (2006.01); C25F 3/00 (2006.01); H01L 21/3213 (2006.01); H01L 27/102 (2006.01); H01L 27/105 (2006.01);
U.S. Cl.
CPC ...
C09K 13/08 (2013.01); H01L 27/1021 (2013.01); H01L 27/1052 (2013.01); H01L 21/32134 (2013.01);
Abstract
A liquid composition for wet etching has improved selectivity for polysilicon over silicon dioxide, even when the polysilicon is heavily doped and/or the silicon dioxide is a low temperature oxide. The composition comprises 0.05-0.4 percent by weight hydrofluoric acid, 15-40 percent by weight nitric acid, 55-85 percent by weight sulfuric acid and 2-20 percent by weight water. A method and apparatus for wet etching using the composition are also disclosed.