Analytical Modeling of Capacitance-Voltage Characteristics of GaN Nanowire Junctionless MOSFET

This paper presents a physically based analytical model for electrostatic properties of GaN Nanowire (NW) Junctionless (JL) MOSFET. The evolution of the model involves the solution of quasi two dimensional Poisson equation with appropriate boundary condition incorporating the influence of NW radius, oxide thickness and doping concentration. The solution results in a relationship between surface potential and applied gate voltage. The extraction of surface potential facilitates the calculation of mobile carrier density which is subsequently used to formulate gate capacitance as a function of gate bias. Furthermore, an analytical model of threshold voltage for long channel GaN NW JL MOSFET has been developed. The impact of various device parameters such as NW radius, oxide thickness and doping concentration on the gate capacitance and threshold voltage has been rigorously investigated. A comparative study between the results obtained from model and 3-D TCAD simulation has confirmed that the analytical model produces satisfactory result in both depletion and accumulation region.