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. 23, 1999
Filed:
Feb. 13, 1997
Applicant:
Inventors:
Assignee:
Semiconductor Energy Laboratory Co., Ltd., Kanagawa, JP;
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
H01L / ;
U.S. Cl.
CPC ...
438585 ; 438197 ; 438694 ; 438751 ; 438754 ;
Abstract
An etching material comprising at least phosphoric acid, acetic acid, and nitric acid, with chromic acid added therein. Also claimed is an etching process using the etching material above, provided that the process comprises selectively etching, by using the solution, an aluminum oxide layer formed on the surface of a material containing aluminum as the principal component thereof.