摘要
A novel Trench MOS Barrier Schottky (TMBS) diode embedded UMOSFET in 4H-SiC is proposed and demonstrated in this work. MOSFETs with TMBS/UMOS ratio of 0, 1/3, and 1/2 are fabricated and evaluated. A UMOSFET where the trench depth is 1.5 mu m and the mesa width is 1.6 mu m shows a R-on,R- sp of 5.8 m Omega cm(2) and a BV of 2040 V. Devices with TMBS cells embedded show no breakdown voltage degradation, and slightly increased R- on,R- sp of 6.9 and 7.3 m Omega cm(2) for devices with TMBS/UMOS ratios of 1/3 and 1/2 respectively. The third quadrant reverse conduction voltage VSD is reduced from 6.3 V to 4.2 V and 3.5 V at a JD of 200 A/cm(2) for devices with TMBS/UMOS =1/3 and 1/2, respectively. DC characteristics at elevated temperatures are measured, from which the temperature dependence of R- on,R- sp and V-TH in the first quadrant and VSD in the third quadrant can be extracted. Finally, the maximum unipolar operating voltage and current are extracted to provide guidelines for operation without bipolar degradation.