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:
Sep. 16, 1997
Filed:
Apr. 26, 1996
Thomas J Martiska, Boylston, MA (US);
Stephen Darling, Worcester, MA (US);
Allegro Microsystems, Inc., Worcester, MA (US);
Abstract
A method of fabricating a patterned polyimide film on a semiconductor wafer including spin coating the wafer with a polyimide precursor solution, baking the polyimide precursor solution in order to remove solvents from and to slightly cure the solution to form a polyimide film, and rinsing the polyimide film with deionized water immediately following the baking step prior to further processing. The rinsing in part serves to further remove solvents associated with the polyimide film. The process continues with photolithography techniques in which the wafer spin coated with a selected photoresist to form a photoresist film immediately following the rinsing step, and a baking of the photoresist film. Thereafter, the photoresist film is exposed to radiation through a photomask, and developed with a solution to form a pattern. The pattern is then etched into the polyimide film with the solution. The remaining portions of the photoresist are removed with a chemical stripper. The wafer is then baked to fully cure the pattern formed in the polyimide film. The present invention provides an improved semiconductor fabrication process which yields better defined patterns and greatly enhances the uniformity and repeatability of the photolithographic process.