10.3 m/spl Omega/-cm/sup 2/, 2 kV Power DMOSFETs in 4H-SiC

Abstract

High voltage power DMOSFETs in 4H-SiC are presented in this paper. A 0.5 μm long MOS gate length was used to minimize the MOS channel resistance. The DMOSFETs were able to block 2 kV with gate shorted to the source. At room temperature, a specific on-resistance of 10.3 mΩ-cm was measured with a gate bias of 12 V. The specific on-resistance was reduced to 8 mΩ-cm with 17 V on the gate. At 150 C, the specific on-resistance increased to 14 mΩ-cm with a VGS of 12 V. The increase in drift layer resistance due to a decrease in bulk electron mobility was partly cancelled out by the negative shift in MOS threshold voltage. The device showed substantially lower parasitic capacitance values compared to a typical silicon power MOSFET with a comparable blocking voltage rating, which suggest that this device can offer significant improvement in switching performance over commercially available silicon power MOSFETs.