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. 01, 2009
Filed:
Mar. 25, 2005
Naoki Makita, Nara, JP;
Misako Nakazawa, Kanagawa, JP;
Hideto Ohnuma, Kanagawa, JP;
Takuya Matsuo, Osaka, JP;
Naoki Makita, Nara, JP;
Misako Nakazawa, Kanagawa, JP;
Hideto Ohnuma, Kanagawa, JP;
Takuya Matsuo, Osaka, JP;
Semiconductor Energy Laboratory Co., Ltd., Kanagawa-Ken, JP;
Sharp Kabushiki Kaisha, Osaka, JP;
Abstract
Problems in prior art regarding an n-channel TFT in the source/drain gettering method are solved. In the n-channel TFT, its source/drain regions contain only an n-type impurity. Therefore, compared to a p-channel TFT whose source/drain regions contain an n-type impurity and a higher concentration of p-type impurity, the gettering efficiency is inferior in a channel region of the n-channel transistor. Accordingly, the problem of inferior gettering efficiency in the n-channel TFT can be solved by providing at an end of its source/drain regions a highly efficient gettering region that contains an n-type impurity and a p-type impurity both with the concentration of the p-type impurity set higher than the concentration of the n-type impurity.