Improved performance of 4H-silicon carbide metal semiconductor field effect transistors with multi-recessed source/drain drift regions

An improved structure of 4H-silicon carbide metal semiconductor field effect transistors with multi-recessed source/drain drift regions (MRD-MESFET) is proposed in this paper. The multi-recessed source/drain drift regions have been introduced to improve both the breakdown voltage and capacitances characteristics. Simulated results indicate that the breakdown voltage of the MRD-MESFET is 141 V compared to 119 V of the reported structure with only single-recessed source/drain region (SRD-MESFET). The output maximum power density is almost 19.1% larger than that of the SRD-MESFET. Also, the cut-off frequency and the maximum oscillation frequency of the proposed structure improve and are 17 GHz and 68 GHz compared to 15 GHz and 59 GHz of the SRD-MESFET due to the decrease in gate–source capacitance, respectively. The lowest gate–source capacitance and the gate–drain capacitance of the MRD-MESFET are obtained with an optimized drain deeper recessed drift region length of 0.2 μm which contribute to superior RF characteristics of MESFETs.