Effective Suppression of IV Knee Walk-Out in AlGaN/GaN HEMTs for Pulsed-IV Pulsed-RF With a Large Signal Network Analyzer

• Published in: IEEE microwave and wireless components letters 2006-12, Vol.16 (12), p.681-683
• Main Authors: Seok Joo Doo, Roblin, P., Jessen, G.H., Fitch, R.C., Gillespie, J.K., Moser, N.A., Crespo, A., Simpson, G., Jon King
• Format: Article
• Language: English
• Subjects: Aluminum gallium nitride; Applied sciences; Devices; Electronics; Exact sciences and technology; Excitation; Gallium nitride; Gallium nitrides; GaN; HEMTs; high electron mobility transistor (HEMT); High electron mobility transistors; Knee; Knees; large signal network analyzer (LSNA); load-line; MODFETs; Networks; Pulse measurements; Radio frequencies; Radio frequency; RF signals; Semiconductor devices; Semiconductor electronics. Microelectronics. Optoelectronics. Solid state devices; Signal analysis; Thermal loading; Transistors; traps
• ISSN: 1531-1309; 2771-957X; 1558-1764; 2771-9588
• DOI: 10.1109/LMWC.2006.885632

IV knee walk-out in AlGaN/GaN high electron mobility transistors (HEMTs) on a Sapphire substrate is analyzed using dynamic radio frequency (RF) load-lines acquired with a large signal network analyzer (LSNA) for both continuous-wave (CW) and pulsed-IV/RF excitations. When thermal effects and traps are bypassed using pulsed-IV biasing and pulsed-RF excitations, the IV knee walk-out observed in CW load-lines is found to be effectively suppressed and the device delivers the maximum output power expected for class A operation. It is also demonstrated using pulsed-IV/RF measurements at various substrate temperatures that the IV knee walk-out primarily arises from thermal effects at high bias rather than trapping in the on-wafer devices characterized