I-V anomalies on InAlAs/InGaAs/InP HFETs and deep levels investigations

摘要

In this paper, static measurements and defect analysis performed on InAlAs/InGaAs/InP HFETs are presented. I_d-V_(ds)-T, I_d-V_(gs)-T and I_g-V_(gs)-T characteristics show anomalies (leakage current, degradation in saturation current, kink effect, distortions on I_d-V_d characteristics in saturation region after high voltage application, ...). Deep defects analysis performed by means of capacitance transient spectroscopy (C-DLTS) and frequency dispersion of the output conductance (G_(ds)(f)) prove the presence of deep defects with activation energies ranging from 0.12 to 0.75 eV. The presence of generation-recombination centers, acting like traps, is confirmed by I_g-V_(gs). The localization and the identification of these defects are presented. Finally, the correlation between the anomalies observed on output characteristics and defects is discussed.