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:
Apr. 03, 2007
Filed:
Nov. 30, 2004
Kinya Ohtani, Kanagawa, JP;
Kinya Ohtani, Kanagawa, JP;
NEC Electronics Corporation, Kawasaki, Kanagawa, JP;
Abstract
A semiconductor substrate used for fabricating vertical devices, such as vertical MOSFET, capable of maintaining low ON-stage resistance and of ensuring a necessary level of OFF-stage breakdown voltage is provided. A heavily-doped arsenic layer of 0.5 to 3.0 μm thick is inserted between a heavily-doped phosphorus layer 11 composing the drain of a vertical MOSFET and an n-type drift layer. The heavily-doped arsenic layer functions as a barrier layer which prevents phosphorus from diffusing from the heavily-doped phosphorus layer into the n-type drift layer. This is successful in maintaining spreading of the depletion layer during OFF time of the vertical MOSFET to thereby improve the OFF-stage breakdown voltage, and in maintaining the low ON-stage resistance.