BOTTOM SOURCE NMOS TRIGGERED ZENER CLAMP FOR CONFIGURING AN ULTRA-LOW VOLTAGE TRANSIENT VOLTAGE SUPPRESSOR (TVS)

摘要

A low voltage transient voltage suppressing (TVS) device supported on a semiconductor substrate supporting an epitaxial layer to form a bottom-source metal oxide semiconductor field effect transistor (BS-MOSFET) that comprises a trench gate surrounded by a drain region encompassed in a body region disposed near a top surface of the semiconductor substrate. The drain region interfaces with the body region constituting a junction diode. The drain region on top of the epitaxial layer constituting a bipolar transistor with a top electrode disposed on the top surface of the semiconductor functioning as a drain/collector terminal and a bottom electrode disposed on a bottom surface of the semiconductor substrate functioning as a source/emitter electrode. The body regions further comprises a surface body contact region electrically connected to a body-to-source short-connection thus connecting the body region to the bottom electrode functioning as the source/emitter terminal.

主权项

1. A low voltage transient voltage suppressing (TVS) device supported on a semiconductor substrate supporting an epitaxial layer thereon, said TVS device further comprising:
a bottom-source metal oxide semiconductor field effect transistor (BS-MOSFET) comprising a planar gate disposed adjacent to a drain region encompassed in a body region disposed near a top surface of said epitaxial layer wherein said epitaxial layer and semiconductor substrate functioning as a bottom source region of said BS-MOSFET and said drain region encompassed in said body region on top of said epitaxial layer constituting a bipolar transistor with a top electrode disposed on said top surface of said semiconductor substrate functioning as a drain/collector terminal and a bottom electrode disposed on a bottom surface of said semiconductor substrate functioning as a source/emitter electrode; said body regions being electrically connected to a body-to-source short-connection connecting said body region to said source region; and said drain/collector terminal is connected to said drain region and wherein said gate turning on said BS-MOSFET upon application of a threshold voltage of said BS-MOSFET thus triggering said bipolar transistor for clamping and suppressing a transient voltage substantially near a threshold voltage of said BS-MOSFET.