Frequency performance of a SiC MESFET with a moderately doped buffer layer

Abstract

ABSTRACTIn this work, we study the impact of a moderately doped P buffer layer below N-type active channel of a Silicon Carbide Metal Semiconductor Field Effect Transistor (SiC MESFET)​​​​​ on its frequency performance. The effect of depletion layer width in the channel developed at the channel–buffer junction has been investigated assuming two separate field regions under the gate. An improved method to calculate mutual and drain conductance of the device is suggested for conventional two-region model. The cut-off frequency and maximum frequency of the device have been calculated and their variations over buffer layer doping density have been presented. The theoretically calculated values of cut-off frequency and maximum frequency of the device have been compared with the experimental value reported earlier and a considerably good agreement has been observed.