Linearity analysis of III-Nitride/β-Ga2O3 Nano-HEMT for emerging RF/Microwave applications

Abstract

This research article proposes a III-nitride Nano-HEMT designed on improved lattice-matched substrate material of β-Ga₂O₃. The Silvaco Atlas tool is utilized to investigate the linearity characteristics of proposed AlGaN/GaN/β-Ga₂O₃ HEMT design for emerging RF/Microwave applications. The proposed device is equipped with an Al_0.12Ga_0.88N back-barrier design that strengthens the charge carrier concentration at GaN/AlGaN heterojunction by raising its conduction band discontinuity. The drop in Al concentration in back-barrier prompted to entire relaxation of lattice. It also efficiently reduces the substrate leakage current, improves RF/Microwave parameters, and bends the conduction band upwardly convex; all of these contribute an improvement in two-dimensional electron gas (2DEG) confinement. Furthermore, field plate arrangement modifies the electric field, adds more feedback capacitance from drain to gate terminal, and triggers a hole current to be suppressed, and the hole depletion area to enlarge. The investigation conducted through simulations demonstrated that the adoption of AlGaN as a back barrier contributed to a noteworthy decrease in leakage current, a positive shift in threshold voltage (-0.18 V), an improved peak transconductance (624 mS/mm), a transconductance generation factor of 8.8 V^− 1, and better intrinsic gain (A_v) and early voltage (V_EA). These excellent findings demonstrate the viability of the proposed Nano-HEMT design for RF/Microwave applications.