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:
Mar. 10, 1998
Filed:
Apr. 26, 1996
Yasuyuki Harada, Tokyo, JP;
Shigeyoshi Netsu, Kuala Lumpur, MY;
Pre-Tech Co., Ltd., Tokyo, JP;
Shin-Etsu Handotai Co., Ltd., Tokyo, JP;
Abstract
An improvement is proposed in the cleaning treatment of semiconductor silicon wafers in which the conventional step of cleaning with an aqueous solution of an alkali is replaced with a cleaning treatment with a temporarily alkaline pure water which is produced electrolytically by the application of a DC voltage between a cathode and an anode bonded to the surfaces of a hydrogen-ion exchange membrane so that the alkaline cleaning treatment can be performed under mild conditions so as to eliminate the troubles due to formation of COPs unavoidable in the conventional process. In addition, the pure water rinse following the alkali cleaning of the wafers before transfer to the succeeding acidic cleaning step can be omitted to greatly contribute to the improvement of productivity. The apparatus used therefor comprises a rectangular vessel divided into a central cathode compartment, in which the wafers are held in a vertical disposition within an up-flow of pure water, and a pair of anode compartments by partitioning with a pair of hydrogen-ion exchange membranes, on both sides of which a cathode plate and anode plate are bonded.