Scaled (LG = 0.1 μm) GaN HEMT technology is currently pursued for high-frequency applications (such as 5G), requiring high current/speed and blocking capability. However, traps introduced with intentional Fe doping yield time-dependent breakdown voltage (VBR), seriously affecting reliability. Here, we investigate the role of Fe traps by pulsed I-V characterization performed at different pulse durations (TOFF). A TOFF-dependent VBR is observed on tested devices and is ascribed to the time-dependent occupancy of deep acceptors in the buffer layer. More specifically, the decrease in VBR for short pulses is attributed to the increased leakage due to the reduced ionization of Fe-traps. This interpretation is supported by 2D numerical simulations.
Fe-Traps Influence on Time-dependent Breakdown Voltage in 0.1-μm GaN HEMTs for 5G Applications / Cioni, M.; Zagni, N.; Chini, A.. - (2022), pp. 11-11B35. (Intervento presentato al convegno 2022 IEEE International Reliability Physics Symposium, IRPS 2022 tenutosi a Dallas, TX, USA nel 2022) [10.1109/IRPS48227.2022.9764502].