SIMULATION OF STATIC SURFACE STATES IN AlGaN/GaN HEMT INCLUDING HOT ELECTRON AND QUANTUM EFFECTS

Abstract

Two-dimensional simulations of hot electron and quantum effects in AlGaN / GaN HEMT devices are performed. The effect of surface states is accounted for by defining effective net surface charges in our simulation. Simulation results show that surface states and surface traps which model the electron depletion play an important role in the electrical characteristic of AlGaN / GaN HEMT. Hot electrons play an important role in the charge transport by spilling over into the bulk GaN where they are captured by traps. Excessive net surface charges make the 2DEG much hotter through the role of vertical electric field above the channel. Lattice scattering and electron tunneling are enhanced with the increasing density of net surface charges, and electron mobility and saturation velocity are significantly reduced.