An analytical physics-based model for low-field mobility in nitride high-electron-mobility transistor considering the momentum relaxation and two-dimensional electronic gas effective mass

Abstract

Accurate modeling of two-dimensional electron gas (2DEG) parameters in AlGaN/GaN high-field electron mobility transistors is essential to gain a deep physical understanding of electron transport. To date, no fully analytical model relates the low-field mobility of 2DEG to the scattering mechanisms. This work presents a model that analytically describes the momentum relaxation time of electrons, low-field electron mobility, and the effective mass of a 2DEG. The proposed model for the momentum relaxation time has been validated through numerical simulation and shows good agreement over a broad range of parameters. Moreover, the total low-field electron mobility, effective mass, and momentum relaxation time of 2DEG were examined by comparing them with optical Hall effect measurements data for the AlGaN/GaN high electron mobility transistor structure with different mole fractions. The comparison showed a good agreement, ensuring the validity of the model. The model can be utilized within physics-based models to enhance their predictive capabilities.