Drain Current DLTS Measurements of MBE-Grown GaAs/InyGa1-yAs/AlxGa1-xAs HEMTs

Modulation-doped GaAs/In
0.25
Ga
0.75
As/Al
0.3
Ga
0.7
As HEMT structures were grown using different MBE-growth temperatures and In
0.25
Ga
0.75
As channel thicknesses. Drain current DLTS measurements performed on these samples using a Fourier-Transform technique show that the concentrations of both bulk and interface traps depend greatly on growth temperature. In addition, a broadening of one of the DLTS peaks was observed for high channel thickness and is shown to be related to a high increase in dislocation concentration.