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. 26, 1994
Filed:
Apr. 30, 1992
Applicant:
Inventor:
Hermanus L Peek, Eindhoven, NL;
Assignee:
U.S. Philips Corp., New York, NY (US);
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
H01L / ;
U.S. Cl.
CPC ...
1566591 ; 437 35 ; 437 67 ;
Abstract
For manufacturing an implantation mask on a semiconductor surface which is provided with grooves, a positive photoresist is provided on the surface. Portions of the photoresist which are to form the implantation mask are illuminated in a first step and rendered insoluble in the developer in an image reversal step. The photoresist is then illuminated without mask and developed, so that the portions not illuminated during the first step are removed. The implantation mask thus obtained has a receding profile, the openings at the area of the grooves becoming wider in the direction of the bottom of the grooves.