The theoretical analysis of breakdown model for a deep trench superjunction (DT-SJ) SiC VDMOS is presented in this paper. The vertical electric field distribution is derived by the electric field decomposition. Then, a fitting dependence of the critical electric field on the doping concentration for the device is obtained, based on which, the model of breakdown voltage is given for the DT-SJ SiC VDMOS. Analytical results are compared with simulative results with the same thicknesses of drift region from 8 μm to 16 μm and the doping concentrations from 4 × 1016 cm-3 to 8 × 1016 cm-3. It is numerically demonstrated that the errors between model and simulation are less than 3% when N pillar and P pillar have the same width of 1μm.
