[IEEE 2018 IEEE 6th Workshop on Wide Bandgap Power Devices and Applications (WiPDA) - Atlanta, GA, USA (2018.10.31-2018.11.2)] 2018 IEEE 6th Workshop on Wide Bandgap Power Devices and Applications (WiPDA) - Analysis of 1.2 kV 4H-SiC Trench-Gate MOSFETs with Thick Trench Bottom Oxide

摘要： The 1.2 kV-rated trench-gate SiC power MOSFET with thick trench bottom oxide is analyzed and compared with previous trench-gate SiC power MOSFET structures. Speci?c on-resistance (Ron,sp), breakdown voltage (BV), threshold voltage (VT H ), gate-drain capacitance (Cgd,sp) and gate charge (Qgd) were extracted using numerical simulations for trench bottom oxide thickness between 500 ?A and 8000 ?A. It was found that the electric ?eld in the trench bottom oxide was below 4 MV/cm for oxide thickness beyond 4000 ?A. An analytical model is proposed to allow estimation of the electric ?eld in the trench bottom oxide. The Ron,sp for the thick bottom oxide structure was 1.9 m? ? cm2 (at Vgs of 20 V), Cgd,sp (at Vds= 1000 V) was 417 pF/cm2 and Qgd,sp (at Vgs =20 V, Rg=10 ?, Vds=800V) was 671 nC/cm2, which is signi?cantly better than most planar-gate devices. This structure has superior speci?c on-resistance compared with previous trench-gate and planar-gate structures.