Title :
Trap studies in GaInP/GaAs and AlGaAs/GaAs HEMT´s by means of low-frequency noise and transconductance dispersion characterizations
Author :
Chan, Yi-Jen ; Pavlidis, Dimitris
Author_Institution :
Dept. of Electr. Eng. & Comput. Sci., Michigan Univ., Ann Arbor, MI, USA
fDate :
5/1/1994 12:00:00 AM
Abstract :
The presence of traps in GaInP/GaAs and AlGaAs/GaAs HEMT´s was investigated by means of low frequency noise and frequency dispersion measurements. Low frequency noise measurements showed two deep traps (E a1=0.58 eV, Ea2=0.27 eV) in AlGaAs/GaAs HEMT´s. One of them (Ea2) is responsible for the channel current collapse at low temperature. A deep trap (Ea1´=0.52 eV) was observed in GaInP/GaAs HEMT´s only at a much higher temperature (~350 K). These devices showed a transconductance dispersion of ~16% at 300 K which reduced to only ~2% at 200 K. The dispersion characteristics of AlGaAs/GaAs HEMT´s were very similar at 300 K (~12%) but degraded at 200 K (~20%). The low frequency noise and the transconductance dispersion are enhanced at certain temperatures corresponding to trap level crossing by the Fermi-level. The transition frequency of 1/f noise is estimated at 180 MHz for GaInP/GaAs HEMT´s and resembles that of AlGaAs/GaAs devices
Keywords :
Fermi level; III-V semiconductors; aluminium compounds; deep levels; electron traps; gallium arsenide; gallium compounds; high electron mobility transistors; hole traps; indium compounds; random noise; semiconductor device noise; 1/f noise; 200 to 350 K; AlGaAs-GaAs; AlGaAs/GaAs HEMTs; Fermi-level; GaInP-GaAs; GaInP/GaAs HEMTs; HEMT; LF noise; channel current collapse; deep traps; frequency dispersion measurements; low temperature; low-frequency noise; transconductance dispersion characterization; Degradation; Dispersion; Frequency estimation; Frequency measurement; Gallium arsenide; HEMTs; Low-frequency noise; Noise measurement; Temperature; Transconductance;
Journal_Title :
Electron Devices, IEEE Transactions on
