Impact of InGaN back barrier layer on performance of AIInN/ AlN/GaN MOS-HEMTs

摘要

In the present work, we have discussed the effect of InGaN back barrier on device performances of 100 nm gate length AlInN/AlN/GaN metal oxide semiconductor high electron mobility transistor (MOS-HEMT) device and a wide comparison is made with respect to without considering the back barrier layer. The InGaN layer is introduced in the intension to raise the conduction band of GaN buffer with respect to GaN channel so that there is an improvement in the carrier confinement and at the same time witnessed excellent high frequency performance. The simulations are carried out using 2D Sentaurus TCAD simulator using Hydrodynamic mobility model by taking interface traps into consideration. Due to high value of two-dimensional electron gas (2DEG) density and mobility in AlInN/AlN/ GaN MOS-HEMT device, higher drain current density is achieved. Simulation are carried out for different device parameters such as transfer characteristic (I_d-V_g), transconductance factor (g_m), drain induced barrier lowering (DIBL), Subthreshold slope (SS), conduction band energy, transconductance generation factor (g_m/I_d) and electric field. We have also examined the RF performance such as, total gate capacitance (C_(gg)), current gain cutoff frequency (f_T) and power gain cutoff frequency (f_(max)) of the proposed devices. Use of InGaN back barrier tends to increase threshold voltage towards more positive value, reduced DIBL, and improves SS and significant growth in (g_m/I_d) by 5.5%. It also helps to achieve better frequency response like substantial increase in f_T up to 91 GHz with current gain 60 dB as compare to 67 GHz with 56 dB for the device without considering back barrier and increase in f_(max) up to 112 GHz with respect 94 GHz. These results evident that use of InGaN back barrier in such devices can be better solution for future analog and RF applications.