Numerical Investigation of the DC and RF Performances for a 4H-SiC Double Delta-Doped Channel MESFET Having Various Delta-Doping Concentrations
A double delta-doped channel 4H-SiC MESFET is proposed to kick out degradation of the DC and RF performances caused by the surface traps, by forming a quantum-well-like potential well and separating an effective channel from the surface. To obtain an optimum device structure, the DC and RF performances of double delta-doped channel MESFETs having various delta-doping concentrations but the same pinch-off voltage with that of conventional MESFET were also investigated. The SilvacoTM simulation results show that the double delta-doped channel MESFET achieved more improvement of the drain current, the cut-off frequency, and the maximum oscillation frequency for higher delta-doping concentration near the gate. In all cases, DC and RF performances for double delta-doped channel MESFETs are much improved than those of the conventional MESFET.