3D Simulation Study of Laterally Gated AlN/β-Ga2O3 HEMT Technology for RF and High-Power Nanoelectronics

Abstract

AbstractIn this work, we present the effect of buried gate dimensions on electron mobility in a laterally gated AlN/β-Ga2O3 high-electron-mobility-transistor (HEMT) using 3D numerical simulations. The recessed parts of the gate laterally control the two-dimensional-electron-gas (2DEG) density in the channel as opposed to vertical control in the conventional planar HEMT. The constant low-field mobility model accounting for lattice temperature and field-dependent mobility model accounting for negative differential carrier mobility are evoked to analyze the electric field and carrier concentration by varying the channel width (WC). A maximum drain current density of 0.8 and ~1 A/mm is obtained using a constant low-field and field-dependent mobility model, respectively, in the device with a gate length (LG) of 0.1 µm and channel width of 100 nm. It is found that with increasing bias voltage, electron mobility starts decreasing due to rising lattice temperature in the constant low-field mobility model, whereas higher electric field-led carrier velocity saturation is attributed to lower mobility in the field-dependent mobility model.Keywords3D Simulation2DEGβ-Ga2O3AlNLinearityLateral-Gate HEMT