A HfO2 based 800V/300°C Au-free AlGaN/GaN-on-Si HEMT technology

Innovative 800V/300°C AlGaN/GaN-on-Si high electron mobility transistors (HEMTs) fabricated with a 4-inch Si CMOS compatible technology are presented in this paper. High performance AlGaN/GaN MIS gated HEMT (MIS-HEMT) and passivated HEMT (i-HEMT) were fabricated using 5nm-thick HfO₂, and 30nm-thick CVD Si₃N₄ as the gate and passivation insulator, respectively. Contact resistance maps yield reduced R_c of 1.32±0.26 Ωmm for Au-free compared to 0.86±0.58 Ωmm for conventional Au-based Ohmic metallization. The off-state breakdown voltage is around 800V with a specific on-resistance of 2 mΩcm². Gate and drain leakage currents as well as dynamic I-V trapping are significantly improved with the MIS-HEMT architecture with almost no trade-off to the on-state.