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:
May. 25, 2010
Filed:
Jan. 30, 2008
Akio Yazaki, Yokohama, JP;
Mikio Hongo, Yokohama, JP;
Takeshi Sato, Kokubunji, JP;
Takahiro Kamo, Tokyo, JP;
Akio Yazaki, Yokohama, JP;
Mikio Hongo, Yokohama, JP;
Takeshi Sato, Kokubunji, JP;
Takahiro Kamo, Tokyo, JP;
Hitachi Displays, Ltd., Mobara-shi, JP;
Abstract
In crystallization of a silicon film by annealing with a linear-shaped laser beam having an ununiform width of the short axis of the beam, the profile (intensity distribution) of the laser beam is evaluated, and the result is fed back to an oscillating condition of the laser beam or an optical condition which projects this onto the silicon film, whereby a display device comprising a high-quality crystalline silicon film is produced. In the present invention, (1) the energy distribution of the linear-shaped laser beam is measured by a detector type CCD camera moved stepwise in the directions that its long axis and short axis extend, respectively, (2) a value obtained by dividing an accumulated intensity E in the long axis direction obtained by accumulating the detected signals in a direction parallel to the short axis by the square root of the width W of the short axis of the linear-shaped laser beam in each position in the long axis: E/√{square root over ( )}(W), is determined in all the positions of a cross section of the linear-shaped laser beam. Since a laser power which is suitable for lateral crystal growth of the silicon film has a close correlation with E/√{square root over ( )}(W), this value is used as an evaluation result mentioned above in the present invention.