Investigation of enhancement mode HfO2 insulated N-polarity GaN/InN/GaN/In0.9Al0.1N heterostructure MISHEMT for high-frequency applications

摘要

In this paper, we examined normally-OFF N-polar InN-channel Metal insulated semiconductor high-electron mobility transistors (MISHEMTs) device with a relaxed In0.9Al0.1N buffer layer. In addition, the enhancement mode operation of the N-polar structure was investigated. The effect of scaling in N-polar MISHEMT, such as the dielectric and the channel thickness, alter the electrical behavior of the device. We have achieved a maximum drain current of 1.17 A/mm, threshold voltage (V-T) = 0.728 V, transconductance (g(m)) of 2.9 S mm(-1), high I-ON/I-OFF current ratio of 3.23x10(3), lowest ON-state resistance (R-ON) of 0.41 Omega mm and an intrinsic delay time (tau) of 1.456 Fs along with high-frequency performance with f(t)/ f(max) of 90 GHz/109 GHz and 180 GHz/260 GHz for T-CH = 0.5 nm at V-ds = 0.5 V and 1.0 V. The numerically simulated results of highly confined GaN/InN/GaN/In0.9Al0.1N heterostructure MISHEMT exhibits outstanding potential as one of the possibility to replace presently used N-polar MISHEMTs for delivering high power density and frequency at RF/power amplifier applications.