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:
Jan. 18, 2005
Filed:
Jun. 25, 2003
Shuichi Kikuchi, Oizumi-machi, JP;
Masafumi Uehara, Oizumi-machi, JP;
Eiji Nishibe, Oizumi-machi, JP;
Katsuyoshi Anzai, Oizumi-machi, JP;
Shuichi Kikuchi, Oizumi-machi, JP;
Masafumi Uehara, Oizumi-machi, JP;
Eiji Nishibe, Oizumi-machi, JP;
Katsuyoshi Anzai, Oizumi-machi, JP;
Sanyo Electric Co., Ltd., Osaka, JP;
Abstract
A withstand voltage against electrostatic discharge of a high voltage MOS transistor is improved. An N-type drain layer is not formed under an N-type drain layer, while a P-type buried layer is formed in a region under the N-type drain layer. A PN junction of high impurity concentration is formed between the N-type drain layer and the P-type buried layer. In other words, a region having low junction breakdown voltage is formed locally. The surge current flows through the PN junction into the silicon substrate before the N-type drain layer below a gate electrode is thermally damaged. Hence, the ESD withstand voltage is improved.