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:
Mar. 09, 2004
Filed:
Dec. 10, 1999
Shigenobu Maeda, Tokyo, JP;
Takashi Ipposhi, Tokyo, JP;
Hirotada Kuriyama, Tokyo, JP;
Hiroki Honda, Tokyo, JP;
Renesas Technology Corp., Tokyo, JP;
Abstract
A channel region ( ), a source region ( ) and a drain region ( ) are formed on a polycrystalline semiconductor layer ( ). The characteristic of a polycrystalline TFT ( ) is dispersed by the amount of crystal grain boundaries ( ) contained in the channel region ( ). A drain current is reduced as the amount of the crystal grain boundaries ( ) contained in the channel region ( ) is increased. In order to utilize a code obtained by encoding the electric characteristic of the TFT ( ) for identification of a semiconductor chip, a system or the like, the TFT ( ) is mounted on the semiconductor chip, the system or the like along with an encoder circuit. Thus, a barrier against illegal use of a user terminal is improved at a low cost.