Design and Investigation of Recessed-T-Gate Double Channel HEMT with InGaN Back Barrier for Enhanced Performance

In this paper, a novel recessed T-gate double channel HEMT with InGaN back barrier has been designed and studied. The double channel is formed by the AlN layer's insertion below the InAlN/GaN interface, enhancing the drain current density (2.5A/mm). However, double channel HEMT suffers from a lack of gate controllability, due to which device performance decreases. This problem has been resolved by using the InGaN as a back barrier which enhances the carrier confinement of 2DEG by raising the conduction band for the GaN buffer and significantly enhances the gate controllability over a lower channel. Precisely a brief comparison has been done of the proposed device with conventional double channel HEMT. Performance parameters like drain current (Ids), transconductance (gm), intrinsic gain (Av), output conductance (gd), early voltage (VEA), TGF, parasitic capacitances (Cgs, Cgd), cut-off frequency (fT), maximum oscillation frequency (fmax), gain frequency product (GFP), transconductance frequency product (TFP), and gain transconductance frequency product (GTFP) have been investigated. Further, the improvement in linearity parameters such as VIP2, VIP3, IIP3, and 1-dB compression point has been observed by varying the back barrier distance from the lower channel.