Novel vertical power MOSFET with partial GaN/Si heterojunction to improve breakdown voltage by breakdown point transfer terminal technology

Abstract

In this paper, the vertical power MOSFET with partial GaN/Si heterojunction is proposed, and the partial GaN/Si heterojunction double-diffused MOSFET (partial GaN/Si VDMOS) and U-shaped MOSFET (partial GaN/Si UMOS) are simulated. Thanks to the breakdown point transfer technology, the breakdown point is transferred from the high electric field area to the low electric field area, therefore, the breakdown voltage (BV) is improved. Different types of dangling bonds are introduced to simulate the influence of different interface state densities on the forward characteristics of the device, the proposed structure alleviates the influence of interface state occurring in the whole GaN/Si heterojunction VDMOS and UMOS (GaN/Si VDMOS and GaN/Si UMOS). The results show that the BV and the specific on-resistance of partial GaN/Si VDMOS are 325 V and 10.17 mΩ cm2, and of partial GaN/Si UMOS are 279 V and 2.34 mΩ cm2, all of which break the limit relation of silicon.