DC and microwave characteristics of AlN spacer based Al₀.₃₇Ga₀.₆₃N/GaN HEMT on SiC substrates for high power RF applications

Abstract

The DC and RF performance of 30nm gate length enhancement mode (E-mode)AlGaN/AlN/GaN High electron mobility transistor (HEMT) on SiC substrate with heavily doped source and drain region have investigated using Synopsys TCAD tool drift diffusion model at room temperature. The proposed device features are recessed T - gate structure, InGaN back barrier and Si₃N4 passivated device surface. The HEMT exhibits a maximum drain current density of 2.1 [A/mm], transconductance gm of 1680 [mS/mm], current gain cut-off frequency frequency ft of 220 GHz and power gain cut-off frequency fmax of 245 GHz. At room temperature the measured carrier mobility (µ), sheet charge carrier density (ns) and breakdown voltage are 1400 (sm²/V - s), 1.6 X10¹³(Cm‾²) and 14V respectively. The excellent DC and microwave performance of the proposed HEMT is promising candidate for future high power RF applications.