Title :
Trap-related effects in AlGaAs/GaAs HEMTs
Author :
Canali, C. ; Magistrali, F. ; Paccagnella, A. ; Sangalli, M. ; Tedesco, C. ; Zanoni, E.
Author_Institution :
Dipartimento di Elettronica e Inf., Padova Univ., Italy
fDate :
2/1/1991 12:00:00 AM
Abstract :
Some AlGaAs/GaAs HEMTs display output resistance and transconductance frequency dispersions that are strongly dependent on the applied drain bias VDS. These frequency and bias dependences have been observed in devices showing a `kink´ effect in the DC current/voltage characteristics. All such phenomena appear to be closely correlated and, because of the presence of deep levels in the AlGaAs layer, may be correlated to DX centres. Electron trapping and detrapping times, which, at low VDS, are about 3 and 10 μs, respectively, can be reduced by almost one order of magnitude by an increase in the drain voltage. Consequently, the related frequency-dependent phenomena disappear at frequencies higher than few megahertz
Keywords :
III-V semiconductors; aluminium compounds; deep levels; electron traps; gallium arsenide; high electron mobility transistors; AlGaAs-GaAs; DC current/voltage characteristics; DX centres; HEMTs; applied drain bias; bias dependences; deep levels; drain voltage; electron detrapping; electron trapping; frequency dependent effects; frequency-dependent phenomena; kink effect; output-resistance frequency dispersion; transconductance frequency dispersions; trap-related effects;
Journal_Title :
Circuits, Devices and Systems, IEE Proceedings G
