12 research outputs found
Origin of Low-Frequency Negative Transconductance Dispersion in p-HEMT
Measurements of low-frequency transconductance dispersion at different
temperatures and conductance deep level transient spectroscopic(CDLTS) studies
of an AlGaAs/InGaAs pseudomorphic HEMT were carried out. The experimental
results show the presence of defect states at the AlGaAs/InGaAs
hetero-interface. A mobility degradation model was developed to explain the low
frequency negative transconductance dispersion as well as the apparent
hole-like peaks observed in the CDLTS spectra. This model incorporates a time
dependent change in 2DEG mobility due to ionised impurity scattering by the
remaining charge states at the adjoining AlGaAs/InGaAs hetero-interface