RF Performance Analysis of Conventional and Recessed Gate AlGaN/GaN MOSHEMT using β–Ga 2 O 3 as Dielectric Layer

Abstract

Abstract—In this research paper, a novel heterostructure AlGaN/GaN metal-oxide-semiconductor high electron mobility transistor (MOSHEMT) is proposed, using an ultra-wide bandgap Oxide Gallium (β-Ga2O3) as dielectric layer growth on GaN substrate. The transfer and RF characteristics of the developed device with a recessed T-gate are compared with a conventional T-gate structure by using a two-dimensional (2D) simulation of the TCAD Silvaco Software at 300 K. A positive value of the threshold voltage VTH of 0.56 V and the highest peak transconductance (Gm, max) of 1.15 S/μm were achieved for 2 nm recess gate depth. A very small sub-threshold slope of 66mV/dec was reached. The microwave frequency performances of this device showed an outstanding result. The E-mode device exhibited a cut-off frequency (Ft) of 49 GHz, and a maximum frequency (Fmax) of 60 GHz while the MOSHEMT with conventional gate structure attained to only 38 GHz and 47 GHz respectively. The simulation results make this improved AlGaN/GaN MOSHEMT using a β-Ga2O3 as a dielectric layer suitable for high-frequency electronic applications.