Improved performance of 4H-SiC MESFETs with Γ-gate and recessed p-buffer layer

An improved 4H-SiC MESFET with Γ-gate and recessed p-buffer layer (ΓRP-MESFET) is proposed in this paper. The channel electric field and the gate depletion layer have been modulated by utilizing Γ-gate and introducing recessed p-buffer layer simultaneously in the ΓRP-MESFET structure. The simulated results show that the drain saturation current and the breakdown voltage of the proposed structure are about 18.5% and 19.4% larger than those of the double recessed structure (DR-MESFET), respectively. Therefore, the maximum output power density of 8.17 W/mm can be achieved, which is about 42% higher than that of the reported one. The cut-off frequency (fT) of the proposed structure is 19.8 GHz, which is higher than that of the conventional structure due to its smaller gate-source capacitance (Cgs).