Variation of gate sidewall angle in V-shaped gate HEMTs impacts the device electrical performance, including self-heating efects, high-frequency operation and the breakdown electric feld. In this paper, the infuence of θ on the electrical characteristics of a nanoscale V-shaped gate HEMT is investigated. The electrical characteristics of the device are calculated as a function of gate sidewall angle to predict an appropriate θ which yields optimum performance. Our results reveal that although smaller sidewall angles allow for a higher device maximum operating temperature by improving self-heating efects, they render a smaller breakdown voltage and have a negligible efect on the drain current as well as the threshold voltage. Furthermore, reducing the sidewall angle deteriorates the device cut-of frequency by increasing the gate-source and gate-drain capacitances. This study underscores the fundamental role of the appropriate gate sidewall angle on device performance.
