Identification of GaN Buffer Traps in Microwave Power AlGaN/GaN HEMTs Through Low Frequency S-Parameters Measurements and TCAD-Based Physical Device Simulations

IEEE Journal of the Electron Devices Society

Julien Couvidat¹  Raphael Sommet¹  Nandha Kumar Subramani¹  Jean-Christophe Nallatamby¹  Raymond Quere¹  Ahmad Al Hajjar¹ 

[1] University of Limoges, CNRS, XLIM, UMR 7252, Brive, France;

关键词: Gallium-nitride (GaN);    high electron mobility transistor (HEMT);    buffer traps;    TCAD simulation;    low frequency S-parameters;   

DOI  :  10.1109/JEDS.2017.2672685

来源: DOAJ

【 摘 要 】

In this paper, the type, activation energy (E_a) and cross section (σ_n) of the GaN buffer traps existing in the AlGaN/GaN high-electron mobility transistors are investigated through low frequency (LF) S-parameters measurements. Furthermore, we present the 2-D physics based TCAD numerical simulation analysis of this device. The dc simulation results are calibrated to match with the experimentally measured I-V characteristics and this allows to qualitatively estimate the concentration of traps (N_T) present in the GaN buffer. Knowing the measured trap energy level and the estimated trap concentration N_T, TCAD physical simulations are performed at various temperatures in order to extract the LF-Y₂₂ admittance parameter. Interestingly, the LF-Y₂₂ simulation results are found to be in good agreement with the measurements and this result strongly suggests that LF admittance dispersion is an effective tool in identifying the traps present in the GaN buffer. Moreover, this paper reveals that acceptor-like traps with an apparent concentration of 5.0 × 10¹⁶ cm^-3 and with the apparent trap energy level of 0.4 eV below the conduction band are located in the GaN buffer.

【 授权许可】

Unknown