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:
Feb. 23, 1999
Filed:
Nov. 07, 1997
Nippondenso Co., Ltd., Kariya, JP;
Abstract
A high breakdown voltage semiconductor device formed in an SOI structure is disclosed. An MOS transistor composed of a drift layer, p well, a source, a gate, and a drain is formed in an island region surrounded by insulators on a semiconductor substrate. Furthermore, an electricfield-alleviating layer is formed in a bottom portion of the Si island region. The electric-field-alleviating layer is a semiconductor layer of exceeding low concentration, e.g., intrinsic, and therefore a virtual PIN structure is structured among the p well and the drift layer. Because the electric-field-alleviating layer corresponds to an I layer of the PIN structure, a depletion layer is created within the electric-field-alleviating layer when high voltage is applied to the MOS transistor, the high voltage is distributed throughout this depletion layer, and high breakdown voltage can be obtained.