<p>A 10 kV-class SiC superjunction (SJ) metal–oxide–semiconductor field-effect transistor (MOSFET) with a split dummy gate (SDG-SJ) is proposed and investigated by technology computer-aided design (TCAD) simulation. To mitigate the compromise issue between the specific on-resistance (<i>R</i>_{on, sp}) and breakdown voltage (BV) in the conventional SiC MOSFET (Con-MOS), the SJ structure is introduced in the ultrahigh-voltage (UHV) MOSFET. Compared to the Con-MOS, the static figure of merit (FOM) (BV²/<i>R</i>_{on, sp}) of the SDG-SJ is improved by a factor of 5.6, which can be attributed to the increased drift region doping concentration and effective electric field modulation. Moreover, the split dummy gate structure is utilized in the proposed device to further improve the dynamic characteristics. The results show that the SDG-SJ exhibits lower reverse transfer capacitance and saturation current, which contributes to enhanced switching and short-circuit capability. The dynamic FOM (<i>R</i>_{on, sp} × <i>Q</i>_GD) of the SDG-SJ is reduced by about 98% compared to the conventional SiC SJ MOSFET (Con-SJ). These exceptional static and dynamic characteristics demonstrate the great potential of the proposed SDG-SJ for UHV applications. Moreover, no supplemental process is required for the fabrication of the proposed device compared to the Con-SJ.</p>