Analysis of fast and slow trap states on electrical performance of AlGaN/GaN HEMTs

Abstract

Experimental observations of simultaneous existence of fast and slow trap states in AlGaN/GaN HEMTs are presented here. The presence of traps with time constants (0.1 ms ~ 0.1 s) and activation energies (0.3 eV~0.54 eV) was detected from transconductance dispersion and admittance curves. These fast traps may assist the high gate leakage currents in AlGaN/GaN HEMTs. The slower traps having the time constants of more than 0.1 s, along with faster traps, may be responsible for hysteresis in the observed output I-V characteristics.