DC and microwave characteristics of 20 nm T-gate InAlN/GaN high electron mobility transistor for high power RF applications

Abstract

The DC and microwave characteristics of 20 nm gate length (Lg) InAlN/GaN High electron mobility transistor (HEMT) on SiC substrate with heavily doped source and drain region have investigated for both depletion mode (D-mode) and Enhancement mode (E-mode) operation using Synopsys TCAD tool. The simulation is performed at room temperature by using drift-diffusion model. The device having the features of recessed T - gate structure, InGaN back barrier and Al2O3 passivated device surface. The proposed novel Lg = 20 nm, W = 2 × 40 μm D-mode (E-mode) HEMT exhibited a peak drain current density (Idmax) of 2.7 (2.6) A/mm, transconductance (gm) of 1.04 (1.63) S/mm, current gain cut-off frequency (ft) of 310 (343) GHz and power gain cut-off frequency (fmax) of 364 (236) GHz. The measured carrier mobility (μ), sheet charge carrier density (ns) and breakdown voltage are 1580 (1615) cm2/V−s, 1.9 × 1013 (1.93) Cm−2 and 10.7 (12.8) V respectively. The superlatives of the proposed HEMTs are bewitching competitor for future sub-millimetre wave high power RF VLSI circuit applications.