Novel Power MOSFET With Partial SiC/Si Heterojunction to Improve Breakdown Voltage by Breakdown Point Transfer (BPT) Terminal Technology

Abstract

In this paper, a new vertical double-diffused metal-oxide semiconductor field effect transistors (VDMOS) is proposed with the partial SiC/Si heterojunction (Partial SiC/Si VDMOS) under the drain electrode in this paper for the first time. The breakdown point transfer technique (BPT) is used to transfer the breakdown point from the radius of curvature is large to the radius of curvature is small in the interface between Pwell and Ndrift region, which causes the longitudinal peak value of electric field to be raised, and the higher breakdown voltage (BV) can be obtained. At the same time, the formation of highly doped N-type silicon trench alleviates interface state problems caused by current flowing through SiC/Si heterojunction and further optimized the whole SiC/Si heterojunction (SiC/Si VDMOS). The limit line of the silicon has been broken because the result is improved between the BV and the specific on-resistance (Ron,sp). Compared with the conventional Si VDMOS, the BV is increased from 238V to 342V, and the Ron,sp is reduced from 14.24mΩ·cm2 to 13.92mΩ·cm2.

Keywords

• VDMOS
• partial SiC/Si heterojunction
• breakdown point transfer technique
• interface state