CAPACITANCE AND DRAIN CURRENT DEEP-LEVEL TRANSIENT SPECTROSCOPY MEASUREMENTS ON MOLECULAR-BEAM EPITAXY-GROWN GAAS IN0.25GA0.75AS/AL0.3GA0.7AS HIGH-ELECTRON-MOBILITY TRANSISTORS/

Modulation doped GaAs/In0.25Ga0.75As/Al0.3Ga0.7As high electron mobili ty transistor structures were grown using different molecular beam epi taxy growth temperatures and In0.25Ga0.75As channel thicknesses. Drain current deep level transient spectroscopy (DLTS) and standard capacit ance DLTS measurements were carried out on these devices using a Fouri er transform technique. The results show that traps in the barriers as well as those in the buffer have an influence on the drain current of such transistors. 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, as confirmed by cathodol uminescene measurements.