AlGaN/AlN/GaN MOS-HEMTs with Al2O3 gate dielectric formed by using ozone water oxidation technique

This work presents Al_0.3Ga_0.7N/AlN/GaN metal-oxide-semiconductor high electron mobility transistors (MOS-HEMTs), grown on the Si substrate, with high-k Al₂O₃ gate dielectric. The present AlGaN/AlN/GaN MOS-HEMT design (the control Schottky-gate HEMT) has showed two-terminal gate-drain breakdown voltage (BV_GD)/turn-on voltage (V_on) of -146.6/1.12 (-96.4/0.98) V, maximum extrinsic transconductance (g_{m, max}) of 167.3 (124.2) mS/mm, saturated I_DS density at V_GS = 0 V (I_DSS0) of 701.4 (538.2) mA/mm, maximum I_DS density (I_{DS, max}) of 927.9 (646) mA/mm, A_V of 211.8 (172.5), unity-gain cut-off frequency (f_T) of 16.8 (11) GHz, maximum oscillation frequency (f_max) of 18.8 (14) GHz, 2.4-GHz output power (P_out) of 17.2 (15.7) dBm, power gain (G_S) of 14.1 (13.4) dB, and power-added efficiency (PAE) of 32.2% (27.4%). Consequently, superior improvements of 52.2% in BV_GD, 43.6% in I_{DS, max}, 34.7% g_{m, max}, and 52.7%/34.3% in f_T/f_max are achieved as compared with a control HEMT device.