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:
Oct. 20, 1998
Filed:
Jun. 30, 1997
Patrick P Dao, Chandler, AZ (US);
Paul William Dryer, Gilbert, AZ (US);
Ping-Chang Lue, Scottsdale, AZ (US);
Michael J Davison, Mesa, AZ (US);
Terry Andrew Willett, Tempe, AZ (US);
Margaret Leslie Kniffin, Tempe, AZ (US);
Rita Prasad Subrahmanyan, Mesa, AZ (US);
Motorola, Inc., Schaumburg, IL (US);
Abstract
A sacrificial oxide etching solution of carboxylic acid and HF having a high etch selectivity for silicon oxide relative to polysilicon, metal, and nitride. The solution is useful in the fabrication of microstructures having integrated electronics on the same chip. A carboxylic acid anhydride can be added to this solution to substantially remove all free water so that the etch selectivity to metal is improved. One specific solution is formed by mixing acetic acid, acetic anhydride, and aqueous HF.