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:
Apr. 30, 1985
Filed:
Jul. 28, 1983
Kenneth G Moerschel, Bethlehem, PA (US);
AT&T Technologies, Inc., New York, NY (US);
Abstract
A production control process includes a method of highlighting pinholes in a surface layer (37), such as a photoresist layer, of an article (31), such as a semiconductor wafer. The photoresist typically covers a dielectric base layer, such as an oxide layer (28). After a typical photoresist application, a typical test wafer (31) is submitted to an etching operation wherein pinhole sized defects in the photoresist layer (37) cause like defects to be etched through the underlying oxide layer (28). Thereafter, the wafer is submitted to an electrolytic treatment step, wherein the preferred process involves treating a positive photoresist in an alcohol with the wafer being cathodically coupled into the treating circuit. Activating light can be used simultaneously with the treatment. As an alternative, the photoresist is exposed prior to the electrolytic treatment of the wafer. During the electrolytic treatment the electrolytic fluid is activated in the immediate area of pinholes to act on the photoresist and dissolve the photoresist immediately about each of the pinholes. The resulting enlarged areas (46) of missing photoresist about each of the pinholes are readily recognized by visual inspection of the wafer (31) at the conclusion of the electrolytic treatment.