DocumentCode :
1192757
Title :
Trapping Effects in the Transient Response of AlGaN/GaN HEMT Devices
Author :
Tirado, José María ; Sánchez-Rojas, José Luis ; Izpura, JoséIgnacio
Author_Institution :
Dept. of Electr., Electron., Control & Commun. Eng., Univ. of Castilla-La Mancha, Toledo
Volume :
54
Issue :
3
fYear :
2007
fDate :
3/1/2007 12:00:00 AM
Firstpage :
410
Lastpage :
417
Abstract :
In this paper, the transient analysis of an AlGaN/GaN high-electron mobility transistor (HEMT) device is presented. Drain-current dispersion effects are investigated when gate or drain voltages are pulsed. Gate-lag and drain-lag turn-on measurements are analyzed, revealing clear mechanisms of current collapse and related dispersion effects. Numerical 2-D transient simulations considering surface traps effects in a physical HEMT model have also been carried out. A comparison between experimental and theoretical results is shown. The presence of donor-type traps acting as hole traps, due to their low energy level of 0.25 eV relative to the valence band, with densities >1e20 cm-3 (>5e12 cm-2), uniformly distributed at the HEMT surface, and interacting with the free holes that accumulated at the top surface due to piezoelectric fields, accounts for the experimentally observed effects. Time constants next to 10 ms are deduced. Some additional features in the measured transient currents, with faster time constants, could not be associated with surface states
Keywords :
III-V semiconductors; aluminium compounds; gallium compounds; high electron mobility transistors; hole traps; semiconductor device models; transient response; wide band gap semiconductors; 0.25 eV; 2D transient simulations; AlGaN-GaN; AlGaN/GaN HEMT devices; AlGaN/GaN high-electron mobility transistor device; HEMT model; donor-type traps; drain-current dispersion effects; drain-lag turn-on measurements; gate-lag turn-on measurements; hole traps; piezoelectric fields; surface traps effects; transient response; trapping effects; Aluminum gallium nitride; Current measurement; Dispersion; Gallium nitride; HEMTs; MODFETs; Numerical simulation; Transient analysis; Transient response; Voltage; AlGaN/GaN high-electron mobility transistor (HEMT); current collapse; device simulation; dispersion effects; donor traps; drain lag; gate lag; hole traps; surface states; trapping effects;
fLanguage :
English
Journal_Title :
Electron Devices, IEEE Transactions on
Publisher :
ieee
ISSN :
0018-9383
Type :
jour
DOI :
10.1109/TED.2006.890592
Filename :
4114862
Link To Document :
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