Electro-thermal characterization of GaN HEMT on Si through selfconsistent energy balance-cellular Monte Carlo device simulations

In order to assess the mechanisms of self-heating observed in GaN HEMTs on Si substrates, we have performed the electro-thermal characterization of an experimental device in terms of the simulation of its DC characteristics through an expanded full band Monte Carlo particle-based simulator self-consistently coupled to an energy balance heat equation for phonons. The accurate temperature profiles obtained for the acoustic and optical phonon modes, showed that the location of the hot spot in the channel is not at the peak of the electric field, but it is shifted towards the drain up to 34nm. Also, the modeled IdVdsVgs space is improved as a result of including the self-heating effects, which modify the charge transport in the active layer of the device through the temperature dependence of the scattering mechanisms considered in the simulations.