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.

Date of Patent:
Jul. 06, 2010

Filed:

Jan. 20, 2005
Applicant:

Makoto Iida, Fukushima, JP;

Inventor:

Makoto Iida, Fukushima, JP;

Assignee:
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
H01L 21/00 (2006.01); C30B 21/04 (2006.01); C30B 15/26 (2006.01);
U.S. Cl.
CPC ...
Abstract

A method for producing semiconductor wafers, from a semiconductor ingot, wherein an oxygen concentration distribution in the growth axis direction is measured in the ingot state (F), a position at which the oxygen concentration is maximum or minimum in a range of a predetermined length is determined as a cut position according to the measurement results (F), the ingot is cut in a perpendicular direction to the growth axis at the cut position into blocks each having the oxygen concentrations being maximum and minimum at both ends thereof (F), each of the blocks is sliced, and thereby semiconductor wafers are produced. Thereby, there can be provided a technique by which when semiconductor wafers are produced from a semiconductor ingot, wafers having oxygen concentration being in a predetermined standard range can be certainly produced.


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