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. 24, 2015
Filed:
Mar. 08, 2012
Hiroshi Takamura, Ibaraki, JP;
Ryo Suzuki, Ibaraki, JP;
Hiroshi Takamura, Ibaraki, JP;
Ryo Suzuki, Ibaraki, JP;
JX Nippon Mining & Metals Corporation, Tokyo, JP;
Abstract
Provided is a polycrystalline silicon wafer produced by a melting and unidirectional solidification method, where the polycrystalline silicon wafer has a diameter of 450 mm or more, a thickness of 900 μm or more, and an average crystal grain size of 5 to 50 mm, and is made up of one piece. The present invention provides a large-sized polycrystalline silicon wafer having a wafer size of 450 mm or more, of which: mechanical properties are similar to those of monocrystalline silicon wafers; the crystal size is large; the surface roughness is low; the surface has a high cleanliness; the polished surface has less unevenness by having a definite crystal orientation; and the sag value is similar to that of monocrystalline silicon wafers.