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:
Jul. 13, 1999
Filed:
Oct. 31, 1996
Applicant:
Inventors:
Robert T Fayfield, St. Louis Park, MN (US);
Brent D Schwab, Hudson, WI (US);
Assignee:
FSI International, Inc., Chaska, MN (US);
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
C09K / ; C23F / ; C23C / ;
U.S. Cl.
CPC ...
216 58 ; 216 79 ; 216 62 ; 216 65 ; 216 66 ;
Abstract
The uniformity of SiO.sub.2 etching over the surface area of a substrate using a conventional SiO.sub.2 etching reaction, such as a HF/ROH reaction where R is H or alkyl, is improved when the substrate is pretreated before the etch reaction. In the pretreatment the substrate within a process chamber is exposed to UV illuminated halogen gas. Suitable halogen gases are fluorine and chlorine. Oxygen may optionally also be included with the halogen gas. The pretreatment renders the etching uniformity results substantially independent of the storage history of the wafer.