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:
Aug. 25, 2009
Filed:
Jun. 10, 2004
Katsuhiko Nishiwaki, Toyota, JP;
Katsuhiko Nishiwaki, Toyota, JP;
Toyota Jidosha Kabushiki Kaisha, Toyota-shi, JP;
Abstract
To present a semiconductor device capable of operating stably even at large current, by lessening current concentration into the corners of contact opening after switching off and suppressing local heat generation without raising the ON voltage. In an insulated gate transistor divided by P field regionand gate electrode, having N+ emitter regionand P+ emitter region, and controlling conduction between emitter and collector by voltage applied to gate electrode, the shape of contact openingcontacting emitter (N+ emitter regionand P+ emitter region) and emitter electrode is formed of curved lines at four corners. Hence, eliminating right-angle apex, hole current from the field region into the emitter electrode after switching off is prevented from concentrating at one point.