Development of 4.5 mΩ-cm2, 1.2 kV 4H-SiC power DMOSFETs

Abstract

In this paper, a 4.5 mΩ-cm², 1.2 kV power DMOSFETs in 4H-SiC were reported. The devices utilized 10 um thick n-type epilayers with a doping concentration of 9×10¹⁵ cm⁻³ for drift layer. The active area size of 1.2 kV DMOSFET device is 4.5 ×10⁻²cm². The device was able to support a blocking voltage of 1.5 kV with gate electrode shorted to the source electrode. The device shows a leakage current density of 3.8 uA/cm² at a block voltage of 1.2 kV. At room temperature, the 4H-SiC DMOSFET showed a specific on-resistance (Ronsp) of 4.5 mΩ-cm², at a gate bias of 20V (Eox=4.0 MV/cm), which was 44% reduction in Ron,sp, compared to a previously reported. The device demonstrated extremely fast, low loss swithing characteristics(tdon=8ns, tr=14ns, tdoff=44ns, tf=43ns), which suggest that this device can offer significant improvement in switching performance over commercially available silicon power MOSFETs.