Advanced quasi-self-consistent Monte Carlo simulations on high-frequency performance of nanometer-scale GaN HEMTs considering local phonon distribution

As a means of investigating both the electrical and thermal properties in nanometer-scale electron devices within a reasonable computing time, we previously proposed a quasi- self-consistent Monte Carlo simulation method, including spatially dependent electron-phonon scattering rates, and a replica technique for phonon generation which enable us to calculate long-time phonon transport. Using this advanced Monte Carlo method, we succeeded in simulating the high- frequency characteristics of nanometer-scale gallium-nitride high-electron-mobility transistors (HEMTs). The simulations suggest that a shorter gate HEMT exhibits larger performance degradation in cut-off frequency due to the local-heating effect. We also report Monte Carlo simulations of nm-scale GaN HEMTs with heat-removal structures on the surface.