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:
Dec. 22, 2009
Filed:
Oct. 26, 2006
Setsuo Nakajima, Kanagawa, JP;
Ritsuko Kawasaki, Kanagawa, JP;
Setsuo Nakajima, Kanagawa, JP;
Ritsuko Kawasaki, Kanagawa, JP;
Semiconductor Energy Laboratory Co., Ltd., Atsugi-shi, Kanagawa-ken, JP;
Abstract
Protrusions called ridges are formed on the surface of a crystalline semiconductor film formed by a laser crystallization method or the like. A heat absorbing layer are formed below a semiconductor film. When the semiconductor film is crystallized by laser, a temperature difference is produced between a semiconductor filmpositioned above a heat absorbing layerand a semiconductor filmof the other region to produce a difference in thermal expansion at the boundary of the outside endof the heat absorbing layer. This difference produces a strain to form a surface wave. The surface wave starting at the outer periphery of the heat absorbing layer is formed in the vicinity of the heat absorbing layer. When the semiconductor layer is solidified after it is melted, the protrusions of the surface wave remain as protrusions after the semiconductor film is solidified.