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:
Aug. 14, 2007
Filed:
May. 10, 2004
Masataka Ito, Kanagawa, JP;
Kenji Yamagata, Kanagawa, JP;
Yasuo Kakizaki, Kanagawa, JP;
Kazuhito Takanashi, Kanagawa, JP;
Hiroshi Miyabayashi, Kanagawa, JP;
Ryuji Moriwaki, Kanagawa, JP;
Takashi Tsuboi, Kanagawa, JP;
Masataka Ito, Kanagawa, JP;
Kenji Yamagata, Kanagawa, JP;
Yasuo Kakizaki, Kanagawa, JP;
Kazuhito Takanashi, Kanagawa, JP;
Hiroshi Miyabayashi, Kanagawa, JP;
Ryuji Moriwaki, Kanagawa, JP;
Takashi Tsuboi, Kanagawa, JP;
Canon Kabushiki Kaisha, Tokyo, JP;
Abstract
An SOI substrate which has a thick SOI layer is first prepared. Then, the SOI layer is thinned to a target film thickness using as a unit a predetermined thickness not more than that of one lattice. This thinning is performed by repeating a unit thinning step which includes an oxidation step of oxidizing the surface of the SOI layer by the predetermined thickness not more than that of one lattice and a removal step of selectively removing silicon oxide formed by the oxidation. The SOI layer of the SOI substrate is chemically etched by supplying a chemical solution to the SOI layer, and the film thickness of the etched SOI layer is measured. When the measured film thickness of the SOI layer has a predetermined value, a process of chemically etching the SOI layer ends.