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:
May. 18, 1993
Filed:
Aug. 21, 1992
Taira Matsunaga, Yokohama, JP;
Bunshiro Yamaki, Fujisawa, JP;
Kabushiki Kaisha Toshiba, Kawasaki, JP;
Abstract
In an integrated circuit device including a bipolar transistor, MOSFET, and protective diode for the MOSFET, all formed over a semiconductor substrate, the protective diode for holding an adequate electrostatic breakdown voltage for a gate oxide layer of the MOSFET is provided by forming a second conductivity type buried area continuous with, and in contact with, a second conductivity type region at a boundary between the first conductivity type semiconductor substrate and a first conductivity type second semiconductor layer. By doing so, a substantive junction depth Xj is made deeper as a whole with respect to the second conductivity type region. It is, therefore, possible to obtain a protective diode of adequate electrostatic breakdown-voltage characteristic which does not adversely affect the operation of the MOSFET even if a relatively thin semiconductor layer is employed. The resultant integrated circuit device equipped with the aforementioned protective diode can reveal an improved high frequency characteristic.