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. 19, 2007
Filed:
Jul. 15, 2004
Hironaru Yamaguchi, Yokohama, JP;
Kiyoshi Ogata, Tokyo, JP;
Takuo Tamura, Yokohama, JP;
Jun Gotoh, Mobara, JP;
Masakazu Saito, Mobara, JP;
Kazuo Takeda, Tokorozawa, JP;
Hironaru Yamaguchi, Yokohama, JP;
Kiyoshi Ogata, Tokyo, JP;
Takuo Tamura, Yokohama, JP;
Jun Gotoh, Mobara, JP;
Masakazu Saito, Mobara, JP;
Kazuo Takeda, Tokorozawa, JP;
Hitachi Displays, Ltd., Chiba-ken, JP;
Abstract
The average film thickness of an amorphous silicon film formed on a substrate is measured. Then, the amorphous silicon film is irradiated with a laser beam to form a polysilicon film, and the grain size distribution of the polysilicon film is measured. An optimum value of energy density of laser beam irradiation is calculated on the basis of grain size values measured at two points A and B of the polysilicon film. Then, the average film thickness of an amorphous silicon film formed on a subsequent substrate is measured. A value of energy density of laser beam irradiation for the subsequent amorphous silicon film is calculated on the basis of the two average film thicknesses. Accordingly, a uniform polysilicon film of large grain sizes is formed on the whole surface of a large-size substrate to provide polysilicon TFTs in a large area.