Parametric study of metal semiconductor field effect transistor (MESFET)

Abstract

MESFETs (Metal Semiconductor Field Effect Transistor) are usually fabricated in compound semiconductor (Group III-V, Group IV-IV) technologies lacking high quality surface passivation such as gallium arsenide (GaAs), indium phosphide (InP), or silicon carbide (SiC), and are faster but more expensive than silicon-based Junction Field Effect Transistors (JFET) or Metal Oxide Silicon Field Effect Transistors (MOSFET). The gallium arsenide (GaAs) having electron mobility six times higher than silicon (Si). It became an essential instrument in modern electronics as well because of its inherent properties such as high temperature conductivity, very low intrinsic concentration, high frequency, higher band-gap, higher electric field strength breakdown. The MESFETS are the most active components used in microwave communication system. To achievement the better performance of these components’ circuits, it become necessary to develop techniques for high end numerical simulation based on physical and structural mechanisms that govern the operation of these devices and circuits. The properties of MESFET could be determined from an original analytical study based on the resolution of the semiconductor fundamental equations. This thesis analyze several parameters of MESFET such as, Drain-Source Current as a function of Drain-Source Voltage, Transconductance as a function Gate-Source Voltage, , Variation of Gate-Drain Capacitance with Drain-Source Voltage, Variation of Gate-Source Capacitance with Respect to Gate-Source Voltage, Variation of Total Internal Device Capacitance with Gate Length and Modelling of MESFET DC Characteristics in different Temperature using Finite Element Analysis Software COMSOL Multi Physics.