Improved double-recessed P-buffer 4H-SiC MESFETs with partial heavy doped channel

An improved double-recessed P-buffer 4H-SiC MESFETs with partial heavy doped channel (HD-MESFET) is proposed in this paper. Compared with the double-recessed p-buffer layer (DRB-MESFET), because of the concentration gradient from the heavy doped area to the channel under the low gate, which prevents the lateral expansion of the depletion layer toward source under the gate, and increases its longitudinal width, thus the DC and frequency characteristics of the device are improved. The simulations indicate that the drain saturation current of the proposed structure increased by 18.4%. Despite a slight decrease in the breakdown voltage, the maximum output power density was still increased by 16.5%. In addition, the DC transconductance increased by 32%. Moreover, the proposed structure has an effective promotion in threshold voltage, which improves the effectiveness of the device performance.