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. 21, 1992
Filed:
Apr. 25, 1989
Hidehiko Shiraiwa, Gresham, OR (US);
Hisatsugu Shirai, Kawasaki, JP;
Nobuhiro Takahashi, Kawasaki, JP;
Shinichi Nomura, Higashimorokata, JP;
Fujitsu Limited, Kawasaki, JP;
Kyushu Fujitsu Electronics Limited, Kagoshima, JP;
Abstract
A method for preventing contamination caused by residues of etched off patterns etched by photolithographic etching. A considerable amount of small contamination spots on a semiconductor chip are found to be caused by tiny residues of etched off patterns. These residues are formed primarily around the periphery of device areas and mark patterns when their outsides are etched off. The occurence of such residues of etching is increased by anisotropic etching. These residues are dislodged by succeeding steps of the pattern making process, and disperse over the substrate causing small contamination spots. To avoid the detrimental effects of the etching residues, the edges of the mark patterns and device areas are covered with an edge cover which is formed in a step to following the pattern etching process.