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:
Sep. 07, 1993
Filed:
Jun. 18, 1992
Kabushiki Kaisha Toshiba, Kawasaki, JP;
Abstract
In a photothyristor, a main thyristor consisting of a P emitter layer, an N base layer, a P gate base layer and an N emitter layer is formed on a semiconductor substrate. Also a pilot thyristor surrounded with the main thyristor and consisting of a P emitter layer, an N base layer, a P gate base layer and an N emitter layer is formed. In the P gate base layer, a trigger light irradiation surface including the inner surface of a recess is formed on the center of the pilot thyristor. In the N base layer, a crystal defect layer is formed under the trigger light irradiation surface by the irradiation with a radiant ray. A breakdown voltage to protect the thyristor from overvoltage is controlled by the crystal defect layer.