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 considering surface donors at E_C − 0.5 eV and buffer traps at E_C − 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 µm gate length. Moreover, simulated GL and DL transient responses of AlGaN/GaN HEMT with a longer gate length (0.5 µm) are validated with the reported experimental results. The impact of barrier trap at E_C − 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.

本文描述了表面和缓冲层陷阱对静态IV，输出导纳（Y ₂₂）和AlGaN / GaN HEMT的瞬态特性的器件仿真研究。TCAD模拟模型考虑了E _C − 0.5 eV处的表面施主和E _C − 0.47 eV处的缓冲阱，已用于定量地重现测得的DC，Y ₂₂频率色散，栅极滞后（GL）和漏极滞后（DL）栅长为0.25 µm的AlGaN / GaN HEMT的瞬态。此外，已报道的实验结果验证了具有更长栅极长度（0.5 µm）的AlGaN / GaN HEMT的模拟GL和DL瞬态响应。势垒陷阱对E _C的影响−还研究了HEMT特性上的0.45 eV。结果表明，通过将模拟结果与实验数据进行匹配，可以确定导致特定诱集降解的诱集剂（表面或缓冲液）及其浓度和捕获截面。