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:
Sep. 15, 2015
Filed:
Nov. 08, 2013
Shanghai Huahong Grace Semiconductor Manufacturing Corporation;
Abstract
A radio frequency (RF) laterally diffused metal oxide semiconductor (LDMOS) device is disclosed which additionally includes a lightly-doped P-type buried layer under a P-type channel region and a moderately-dope P-type buried layer in the lightly-doped P-type buried layer. The two buried layers result in a lower base resistance for an equivalent parasitic NPN transistor, thereby impeding the occurrence of snapback in the device. Additionally, an equivalent reverse-biased diode formed between the channel region and the buried layers is capable of clamping the drain-source voltage of the device and sinking redundant currents to a substrate thereof. Furthermore, the design of a gate oxide layer of the RF LDMOS device to have a greater thickness at a proximal end to a drain region can help to reduce the hot-carrier effect, and having a smaller thickness at a proximal end to the source region can improve the transconductance of the RF LDMOS device.