Development of 8 mΩ-cm2, 1.8 kV 4H-SiC DMOSFETs

8 m Omega-cm(2), 1.8 kV power DMOSFETs in 4H-SiC are presented in this paper. A 0.5 Pun long MOS gate length was used to minimize the MOS channel resistance. The DMOSFETs were able to block 1.8 kV with the gate shorted to the source. At room temperature, a specific on-resistance of 8 m Omega-cm(2) was measured with a gate bias of 15 V. At 150 degrees C, the specific on- resistance increased to 9.6 m Omega-cm(2). 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 at elevated temperatures. The device demonstrated extremely fast, low loss switching characteristics. A significant improvement in converter efficiency was observed when the 4H-SiC DMOSFET was used instead of an 800 V silicon superjunction MOSFET in a simple boost converter configuration.