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. 26, 2002
Filed:
Apr. 27, 2000
Applicant:
Inventor:
Clifton Walk Draper, Hopewell, NJ (US);
Assignee:
Agere Systems Guardian Corp., Orlando, FL (US);
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
H01L 2/1469 ;
U.S. Cl.
CPC ...
H01L 2/1469 ;
Abstract
The present applicant has discovered that the application of an etch-rate reducing liquid that selectively wets the mask can permit anisotropic wet etching. In a preferred embodiment, the application of a hydrocarbon liquid film to a masked silica surface permits wet etching of straight silica walls without undercutting the mask. It is believed that the oil selectively wets the polymer mask, but not the silica surface. The oil will thus be selectively present at the point where the mask meets the silica. Since the HF etchant does not dissolve the oil, the etching produces straight walls instead of undercutting the mask.