AlGaN/GaN high electron mobility transistors (HEMTs) with
sapphire (Al2O3) substrates reveal anomalies like kink effect,
current collapse, hysteresis phenomena on Ids-Vds and
Ids-Vgs. These parasitic effects can be attributed to the
presence of traps in the hetero-structure. Deep defects analysis was
performed by conductance deep level transient spectroscopy (CDLTS) under
drain pulse. Four electron traps have been detected with activation energy
and capture cross-section of 2.62 eV, 1.18 eV, 0.97 eV, 0.48 eV, σn = 2.4 × 10-17 cm2 and σn = 2.37 × 10-14 cm2, σn = 2 × 10-12 cm2 and σn = 4.67 × 10-14 cm2 respectively. The localisation and the identification of these traps have occurred and a correlation between defects and parasitic effects has been discussed.