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. 13, 2007
Filed:
May. 07, 2003
Silicon single crystal wafer, an epitaxial wafer and a method for producing a silicon single crystal
Masahiro Sakurada, Fukushima, JP;
Nobuaki Mitamura, Fukushima, JP;
Izumi Fusegawa, Fukushima, JP;
Tomohiko Ohta, Fukushima, JP;
Masahiro Sakurada, Fukushima, JP;
Nobuaki Mitamura, Fukushima, JP;
Izumi Fusegawa, Fukushima, JP;
Tomohiko Ohta, Fukushima, JP;
Shin-Etsu Handotai Co., Ltd., Tokyo, JP;
Abstract
In a method for producing a silicon single crystal by Czochralski method, the single crystal is grown with controlling a growth rate between a growth rate at a boundary where a defect region detected by Cu deposition remaining after disappearance of OSF ring disappears when gradually decreasing a growth rate of silicon single crystal during pulling and a growth rate at a boundary where a high oxygen precipitation Nv region having a density of BMDs of 1×10numbers/cmor more and/or a wafer lifetime of 30 μsec or less after oxygen precipitation treatment disappears when gradually decreasing the growth rate further. Thereby, there is provided a silicon single crystal which does not belong to any of V region rich in vacancy, OSF region and I region rich in interstitial silicon, and has excellent electrical characteristics and gettering capability, so that yield of devices can be surely improved, and also an epitaxial wafer.