High figure-of-merit vertical double diffused MOSFET with the charge trenches on partial SOI

Abstract

n" substrate L Gate I I E E, dẼ . T (a) (b) n-type Si T E, E L d D E.Fig. I Structure of a TPSO! VDMOS and the trench cell (a) Structure of a TPSO! VDMOS. (b) Trench cell structure and charge distribut ion(M is in the middle of oxide trenches, N is in the comer of oxide trenches, respectively. M and N are in Si). Drain are the thickness, doping concentration and permittivity of the n' drift layer, respectively. D[ is the distance from the bottom of the buried oxide layer to the surface of the TPSOI VDMOS. HI. L[ and 8[ are the height, half of length and permittivity The n-drift region under the p body is divided into three parts. Region I is the silicon on insulator.Region II is the buried oxide layer. Region III is the silicon Abstract-A novel silicon-on-insulator (SOl) high figure-ofmerit vertical double diffused MOSFET (VDMOS) structure and its breakdown mechanism are presented in this paper. The structure is characterized by oxide trenches on the top interface of the buried oxide layer on partial SOl (TPSOI). The accumulation charges located in the trenches enhance the electric field in the buried oxide layer and uniform the electric field in the drift region, therefore the breakdown voltage (V br ) is enhanced. Simulation shows that the V br and the figure-of-merit of the TPSOI VDMOS increase by 66.8% and 148.1% in comparison with the conventional VDMOS, respectively.

A gate enhanced power U-shaped MOSFET integrated with a Schottky rectifier

“…The quality factor is equal to the ratio of the square of the breakdown voltage to the on-resistance. [10] So the higher the value of Q, the better the performance.…”

“…Conventional UMOSFET [12] 37 0.09 15.2 TPSOI VDMOS [10] 123.4 0.96 15.8 FLI-MOSFET [11] 61 0.42 8.86…”