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:
Feb. 12, 2013
Filed:
Feb. 02, 2010
Joerg Haberecht, Freiberg, DE;
Joerg Haberecht, Freiberg, DE;
Siltronic AG, Munich, DE;
Abstract
Epitaxially coated silicon wafers, are coated individually in an epitaxy reactor by a procedure in which a silicon wafer on a susceptor in the epitaxy reactor, is pretreated in a first step with a hydrogen flow rate of 1-100 slm and in a second step with hydrogen and an etching medium at a hydrogen flow rate of 1-100 slm, and an etching medium flow rate of 0.5-1.5 slm, at an average temperature of 950-1050° C., and is subsequently coated epitaxially, wherein, during the second pretreatment step, the power of heating elements is regulated such that there is a temperature difference of 5-30° C. between a radially symmetrical central region of the silicon wafer and an outer region of the silicon outside the central region.