Fig. 1. (Color online) Schematic cross-sections of (a) the CT-UMOS and (b) proposed SS-UMOS (G & NG) (Please refer to Table 1 for detailed parameters).

Fig. 2. (Color online) Process flow of the proposed SS-UMOS (G & NG) structure of SiC MOSFET.

Fig. 3. (Color online) (a) The transfer characteristic curves (V_DS = 5 V), (b) output characteristic curves and current density of (c) CT-UMOS, (d) GSS-UMOS, (e) NGSS-UMOS. (V_GS = 15 V,V_DS = 20 V)

Fig. 4. (Color online) (a) Breakdown characteristic curves, (b–d) corresponding electric field distributions (V_GS = 0 V,V_DS = 1200 V), two-dimensional electric fields of (e) CT-UMOS and (f) GSS-UMOS (V_GS = 0 V,V_DS = 1200 V), and current density distribution of (g) CT-UMOS and (h) GSS-UMOS at breakdown voltage.

Fig. 5. (Color online) (a) Feedback capacitance C_GD as a function of drain voltageV_DS at gate voltage V_GS = 0 V and (b) voltage V_GS as a function of gate chargeQ_G and the inset is the testing circuit forQ_G.

Fig. 6. (Color online) (a) Test circuit of switch characteristics, (b) voltage and current characteristic of the GSS-UMOS in the switching transients, (c) detailed comparisons of the turn-on and turn-off transients for the CT-UMOS and SS-UMOS (G & NG) at switching frequency of 33 kHz, (d) the switching frequency is 50 kHz, (e) the switching frequency is 75 kHz, (f) comparison of the switching loss at different switching frequencies.

Fig. 7. (Color online) The relationship between the total power loss and switching frequency.