Electrostatics of nanowire transistors with triangular cross sections

The electrostatic properties of nanowire field effect transistors with triangular cross sections were investigated. The Poisson equation was solved for these structures; furthermore, two properties of the nanowire field effect transistors, the gate capacitance and current versus gate voltage, were calculated. The simulation results yielded the type, mobility, and concentration of the carriers, as well as the Ohmic contact resistance of the wire transistor. We examined how wire capacitance depends on various parameters: wire diameter, gate oxide thickness, charge density, and shape. It is shown that the capacitance of a triangular nanowire is less than that of a cylindrical nanowire of the same size, which could be significant in structures with thin gate oxides. The simulation results were compared with the previously reported experimental data on GaN nanowires.