Effect of Doped AlGaN Width Variation on Analog Performance of Dual Gate Underlap MOS-HEMT

Abstract

A Symmetric Heterojunction Underlap Double Gate (U-DG) GaN/AlGaN Metal Oxide Semiconductor High Electron Mobility Transistor (MOS-HEMT) having negatively doped AlGaN region and AlGaN spacer has been studied for varying values of doped AlGaN width in this work. This paper shows a detailed performance analysis of the Analog Figure of Merits (FoMs) with varying doped width. The effect of doping on analog performances of the device has also been scrutinized. The Figure of Merits (FoMs) like variation of Drain Current (I DS ) with Gate Voltage (V GS ) and Drain Current with Drain Voltage (V DS ), Transconductance (g m ), Output Resistance (R 0 ) and Intrinsic Gain (g m R 0 ) have been under investigation alongside the consequences of altering the width of doped AlGaN layer. Conduction band diagrams for both ON and OFF states are used to explain the device behaviour. Studies show that by reducing the width of the doped region in the MOS-HEMT device, better gate controllability is obtained along with higher ON current.