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. 25, 1999
Filed:
Jul. 11, 1997
Fwu-Iuan Hshieh, Saratoga, CA (US);
Koon Chong So, San Jose, CA (US);
MagePower Semiconductor Corp., San Jose, CA (US);
Abstract
A power MOSFET (Metal Oxide Semiconductor Field Effect Transistor) device formed on a semiconductor substrate having a body region of a first conductivity type diffused in a semiconductor substrate with an epitaxial layer of a second conductivity type. There is also a source region of a second conductivity type formed in the body region. A portion of the body region adjacent to the source region is compensated by ion implanting a material of the second conductivity type in the portion of the body region such that the impurity concentration of the body region at the portion is reduced. As a consequence, with reduced impurity charge in the body region adjacent to the source, the threshold voltage of the MOSFET device is lowered but at no comprise in punch-through tolerance because the reduction in charge is remote from the origin of the depletion layer which is located at the boundary between the body region and the epitaxial layer.