Low-noise and high-power AlN/GaN MIS-HEMTs on silicon for mm-wave low-voltage applications

Abstract

The SiN_x/AlN/GaN metal-insulator-semiconductor high electron mobility transistors (MIS-HEMTs) on silicon have been fabricated for low-supply-voltage applications. The devices, featuring a gate length (L_g) of approximately 140 nm, exhibited excellent DC characteristics: a contact resistance (R_c) of 0.24 Ω·mm, a maximum saturated drain current (I_dmax) of 1.86 A/mm at a gate voltage (V_gs) of 2 V, an on-resistance (R_on) of 1.4 Ω·mm, and a peak transconductance (Gm_max) of 466 mS/mm at a drain voltage (V_ds) of 6 V. In RF measurements, the devices achieved ultra-low minimum noise figure (NF_min) of 0.54 (0.66) dB at V_ds of 5 (6) V at 30 GHz, along with a good two-tone linearity, the ratio of output third-order intercept point (OIP₃) to direct current output power (P_dc), denoted as OIP₃/P_dc is 12.4 (9.9) dB at V_ds of 5 (6) V. Pulsed-wave (PW) power measurements indicated the devices have both high output power (P_out) of 1.1 (1.6) W/mm and power-added efficiency (PAE) of 50.2 (49.4 %) at V_ds of 5 (6) V. These results demonstrate the SiN_x/AlN/GaN MIS-HEMTs on silicon have promising potential in low-supply-voltage mm-wave low-noise and high-power applications.