Investigation of traps in AlGaN/GaN HEMTs by current transient spectroscopy

Deep levels in AlGaN/GaN HEMTs on Si substrate are known to be responsible for trapping processes like: threshold voltage shift, leakage current, degradation in saturation current and hysteresis effect. The related deep levels are directly characterized by Conductance Deep Level Transient Spectroscopy (CDLTS) method. Hereby we have detected four carrier traps with activation energy of 0.83, 0.50, 0.20 and 0.07 eV and capture cross-section respectively of σ = 3.14 × 10− 14 cm2, σ = 2.57 × 10− 15 cm2, σ = 3.03 × 10− 17 cm2 and σ = 2.65 × 10− 15 cm2. All these traps are located between the substrate and the two-dimensional electron gas (2DEG) channel.