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:
Jun. 27, 2006
Filed:
Jun. 27, 2002
Kenji Hori, Tokyo, JP;
Kenji Hori, Tokyo, JP;
Mitsubishi Materials Silicon Corp., Tokyo, JP;
Abstract
A method for cleaning polysilicon comprises steps of cleaning solid or granular polysilicon with an aqueous solution of dissolved ozone, and of cleaning with hydrofluoric acid the polysilicon receiving the above cleaning based on an aqueous solution of dissolved ozone, wherein the above steps are executed once in this order, or the above steps are repeated once or more in this order. Subsequent to the last cleaning step using hydrofluoric acid, a still other step of cleaning the polysilicon with pure water and then drying it is preferably added. This method for cleaning polysilicon allows organic materials, particles and metal impurities adsorbed on the surface of polysilicon to be removed at a low cost, and to increase the freeing rate.