DC SHEs on GaN HEMTs varying substrate material

AlGaN/GaN HEMTs with sapphire substrate have been measured and numerically simulated considering self-heating effects. A complete DC performance was realized to extract the main electrical parameters with the aim to obtain a proper characterization of the sample. Afterwards, an accuracy and simple methodology has been established to determine the device thermal resistance with other possible substrates, Si, SiC and Mo, which are more suitable due to their lower thermal conductivity. Finally, we modify a compact model for AlGaN/GaN transistors to include the extrinsic resistances obtained from numerical simulations with all substrates.