Trapping effects on AlGaN/GaN HEMT characteristics

This paper describes device simulation studies of surface and buffer trapping effects on static I-V, output-admittance (Y22), and transient characteristics of AlGaN/GaN HEMTs. The TCAD simulation model consid-ering surface donors at EC -0.5 eV and buffer traps at EC -0.47 eV have been used to quantitatively reproduce the measured DC, Y22 frequency dispersion, gate-lag (GL) and drain-lag (DL) transients of AlGaN/GaN HEMT with 0.25 ?m gate length. Moreover, simulated GL and DL transient responses of AlGaN/GaN HEMT with a longer gate length (0.5 ?m) are validated with the reported experimental results. The impact of barrier trap at EC -0.45 eV on the HEMT properties is also explored. It is shown that by matching simulation results with experimental data, it is possible to identify the trap (surface or buffer) responsible for a particular trapping induced degradation as well as its concentration and capture cross-section.

Automated summary

This paper presents device simulation studies on static I-V, output-admittance (Y22), and transient characteristics of AlGaN/GaN HEMTs, focusing on surface and buffer trapping effects. By matching simulation results with experimental data, it is possible to identify the trap responsible for specific trapping induced degradation, as well as its concentration and capture cross-section.