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:
Dec. 17, 2002
Filed:
Mar. 10, 1999
Yuichi Nakayoshi, Miyazaki, JP;
Naoki Yamada, Miyazaki, JP;
Komatsu Electronic Metals Co., Ltd., Kanagawa, JP;
Abstract
The present invention provides a method for appraising the condition of a polishing cloth, and a method for manufacturing semiconductor wafers employing the disclosed appraisal method, allowing acceptably low light point defect numbers of semiconductor wafers to be maintained. The disclosed method comprises polishing the semiconductor wafer using a polishing cloth, washing the wafer, and drying the wafer. The size of particles comprising light point defects is chosen, and the number of light point defects on the semiconductor wafer is counted. Typically, the diameter of particles comprising light point defects is set as 0.12 &mgr;m or greater. The polishing cloth is exchanged when the number of light point defects counted exceeds a prescribed number.