Performance analysis of HfO2/InAlN/AlN/GaN HEMT with AlN buffer layer for high power microwave applications
P. Murugapandiyan, A. Mohanbabu, V. Rajya Lakshmi, V. N. Ramakrishnan, Arathy Varghese, Mohd Wasim, S. Baskaran, R. Saravana Kumar, V. Janakiraman
Abstract
We present a performance enhancement evaluation of n + doped graded InGaN drain/source region-based HfO2/InAlN/AlN/GaN/AlN on SiC metal-oxide-semiconductor high electron mobility transistor (MOS-HEMTs) with a T-shaped gate. Impact on the device characteristics with the inclusion of a HfO2 surface passivation layer and an AlN buffer layer in the MOS-HEMT structure as a performance booster has been analyzed for the HEMT device with 30 nm gate length using Silvaco ATLAS TCAD. The proposed MOS-HEMT exhibits an outstanding performance, with an enhanced power gain cut-off frequency (fmax) of 366 GHz, a current gain cut-off frequency (ft) of 426 GHz, and a off-state breakdown voltage (Vbr) of 81 V. The high-k (high permittivity) HfO2 based metal oxide semiconductor HEMT device experiences a low off-state gate leakage current (Ig ~ 10−11A/mm) and a high Ion/Ioff ratio of 109. The InAlN/GaN/AlN heterostructures demonstrate improved two-dimensional electron gas (2DEG ~ 5.3 × 1013 cm−2), carrier mobility (μ) of 1256 Cm2/V-s and drain current density of (Ids) 2.7 A/mm. A large signal analysis performed at 30 GHz yielded a maximum of 28% power-added efficiency. The high JFoM of 34.506 THz V (Johnson Figure of Merit = ft × Vbr) and (ft.fmax)1/2 of 394.86 GHz indicate the potential applicability of the HfO2/InAlN/GaN MOS-HEMTs in high-frequency and high-power applications.