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:
Dec. 14, 1999
Filed:
Sep. 25, 1996
Applicant:
Inventor:
Cozy Ban, Tokyo, JP;
Assignee:
Mitsubishi Denki Kabushiki Kaisha, Tokyo, JP;
Primary Examiner:
Int. Cl.
CPC ...
B05D / ; B05C / ;
U.S. Cl.
CPC ...
156345 ;
Abstract
Semiconductor nitride film etching systems are provided using a hot phosphoric-acid-based treatment solution, wherein the systems contain means for measuring phosphoric acid concentration, silicon concentration, fluorine concentration, or specific gravity or a combination thereof, and additives of the treatment solution are controlled or the treatment solution is exchanged. The concentration of components of the treatment solution, particularly the concentration of silicon, is controlled, thus providing stabilization of the etching rate of a silicon nitride film, and stable control of the etching selection ratio.