MBE-Regrown Ohmics in InAlN HEMTs With a Regrowth Interface Resistance of 0.05 Ω

Nonalloyed ohmic contacts regrown by molecular beam epitaxy were made on InAlN/AlN/GaN/SiC high-electron-mobility transistors (HEMTs). Transmission-line-method measurements were carried out from 4 K to 350 K. Although the total contact resistance is dominated by themetal/ n⁺-GaNresistance (~0.16Ω), the resistance induced by the interface between the regrownn⁺GaN and HEMT channel is found to be 0.05–0.075Ωover the entire temperature window, indicating a minimal barrier for electron flow at the as-regrown interface. The quantum contact resistance theory suggests that the interface resistance can be further reduced to be$<$0.02Ω· mmin GaN HEMTs.