A novel vertical deep trench RESURF DMOS (VTR-DMOS)

Abstract

A new super junction (SJ)-DMOS device, the vertical deep trench RESURF DMOS or VTR-DMOS, is proposed. The VTR-DMOS is a conventional vertical N-channel DMOS with a deep trench adjacent to the gate. The trench creates a vertical sidewall into which boron is solid source diffused to form a P-type doping pillar which is charge balanced to the N-type epitaxial drift region. 2-D simulations comparing a VTR-DMOS to a conventional VDMOS indicate a 5.5/spl times/ improvement in silicon-only Rsp for a BVdss>700 V.