Evaluation of Trap Signatures in Fe-doped 0.12 µm InAlN/GaN HEMTs by DCT, Y22 and Y21 Techniques

International audienceElectrically active defects in 0.12 µm InAlN/GaN high-electron mobility transistors (HEMTs) with Fe-doped buffer are extensively analyzed by drain current transient (DCT), output and forward-transfer admittance (Y22 and Y21) parameters. The DCT, Y22, and Y21 properties are measured at several temperatures (30 °C to 165 °C) to determine the trap parameters using Arrhenius analysis. The measurements are also performed at two distinct drain voltage conditions to quantify the field-assisted (Poole-Frenkel) carrier emission effect on the trap activation energy. All these defect characterizations indicate the Fe-related acceptor trap in the buffer, however each technique yields quite different energies (EC – 0.62 to EC – 0.43 eV), and capture cross-sections (5×10-15 cm2 to 6×10-17 cm2). A shallow trap at EC – 0.13 eV is identified from Y21, which is attributed to the surface trapping. This work is an essential initial step toward estimating the zero-field (actual) activation energy of a trap, by quantitatively incorporating the electric field effects on the emission rate