Two Dimensional Modeling of Nonuniformly Doped MESFET Under Illumination

A two dimensional numerical model of an optically gated GaAs MESFET with non uniform channel doping hasbeen developed. This is done to characterize the device as a photo detector. First photo induced voltage (Vop) atthe Schottky gate is calculated for estimating the channel profile. Then Poisson’s equation for the device issolved numerically under dark and illumination condition. The paper aims at developing the MESFET 2-Dmodel under illumination using Monte Carlo Finite Difference method. The results discuss about the opticalpotential developed in the device, variation of channel potential under different biasing and illumination andalso about electric fields along X and Y directions. The Cgs under different illumination is also calculated. Ithas been observed from the results that the characteristics of the device are strongly influenced by the incidentoptical illumination.