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, 2012
Filed:
Nov. 04, 2009
Koichiro Tanaka, Isehara, JP;
Hirotada Oishi, Atsugi, JP;
Koichiro Tanaka, Isehara, JP;
Hirotada Oishi, Atsugi, JP;
Semiconductor Energy Laboratory Co., Ltd., Atsugi-shi, Kanagawa-ken, JP;
Abstract
It is an object to achieve continuous crystal growth without optical interference using a compact laser irradiation apparatus. A megahertz laser beam is split and combined to crystallize a semiconductor film. At this point of time, an optical path difference is provided between the split beams to reduce optical interference. The optical path difference is set to have a length equivalent to the pulse width of the megahertz laser beam or more and less than a length equivalent to the pulse repetition interval; thus, optical interference can be suppressed with a very short optical path difference. Therefore, laser beams can be applied continuously and efficiently without energy deterioration.