Simulation based electrostatic study of different multigate quantumwell field effect transistors by changing the gate oxide thickness and metal work function

Abstract

This paper analyses the C-V characteristics by altering the gate oxide thickness and metal workfunction used in the gate of non-planer, multi-gate InGaAs channel Quantum Well Field-Effect Transistor (QWFET). In this paper, we tried to distinguish the different aspects of modern day transistors which lead us to the conclusion about the upcoming worldwide uses of QWFET in many electronic devices. Simulations were carried out using COMSOL Multiphysics linked with MATLAB simulator by incorporating various electrostatic parameters of different semiconductor materials in suitable domains with suitable boundary conditions. Poisson solver coupled with Schrodinger equation is used to obtain charge density in each point of the channel region of QWFET, and integrating the overall charge density we obtain total charge. In this way, charge accumulated in the channel region is obtained by altering gate voltage and a graph of charge versus gate voltage is obtained, which is further differentiated with respect to gate voltage to obtain graphs of gate capacitance versus gate voltage by changing the above mentioned parameters.