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:
Nov. 06, 1990
Filed:
Sep. 28, 1988
Helene Prigge, Unterschleissheim, DE;
Anton Schnegg, Burghausen, DE;
Gerhard Brehm, Emmerting, DE;
Herbert Jacob, Burghausen, DE;
Wacker-Chemitronic Gesellschaft fur Elektronik-Grundstoffe mbH, Burghausen, DE;
Abstract
A polishing process in which haze-free semiconductor wafers can be obtained in a single-stage process in which an initial phase of the polishing operation is carried out in the usual manner in the alkaline region. This initial stage is followed by a final phase in which polishing is carried out, at a pH of 3 to 7, in the presence of additives in the polishing agent which reduce the amount of material removed by polishing. Consequently, it may be possible to dispense with polishing agent components which act mechanically. Both phases can be carried out on one and the same equipment without interrupting the polishing operation.