Electrical Characteristics of MESFET Using GaAs, InP and GaN as Substrates

The theoretical analysis of electrical properties of MESFETs has been carried out with different materials of narrow as well as wide energy bandgap III-V binary compound semiconductors. The gate-to-source capacitance (C-gs) and transconductance (g(m)) have been studied as a function of gate-to-source voltage (V-gs). It is revealed that wide bandgap semiconductor is best suited at high frequency because it has lower capacitance. The transconductance also depends on temperature and decreases with temperature. This is because of the increasing scattering phenomenon within the channel. The wide bandgap semiconductors offer higher transconductance which enables them to be used as high-speed switch. The aim of this work is to improve the understanding of MESFET device performances based on different III-V binary compound materials and also to find out the most suitable material combination for MESFET.