1500 V recessed-free GaN-based HEMTs with ultrathin barrier epitaxial structure

This Letter demonstrates a 1500-V enhancement-mode (E-mode) GaN-based high electron mobility transistors (HEMTs) based on the recessed-free structure. The E-mode GaN-based HEMTs fabricated based on the ultrathin barrier epitaxial structure have a small gate interface traps density (Dit) of ∼1012 cm−2 eV−1, which can be attributed to the avoidance of AlGaN etching in the gate region. Meanwhile, a small threshold voltage (Vth) hysteresis of 19 mV and a small subthreshold swing of 101 mV/dec are achieved in the fabricated devices with a Vth around 1.91 V. A small Vth shift of 0.05 V was achieved under positive gate voltage stress, indicating that the devices have good Vth stability. Meanwhile, a high yield of more than 90% has been achieved on 6-in. wafer, which provides a good scheme for the commercialization of E-mode HEMTs.