Abstract
The aim of this work is to study the origin of parasitic effects observed on the output characteristics of InAlAs/InGaAs/InP HEMTs with various buffer layers. I-ds-V-ds measurements as a function of the temperature have first been performed. Several anomalies were observed such as kink and hysteresis effects. C-DLTS measurements have also been performed. From the obtained results, we have established a strong correlation between parasitic effects observed on the output characteristics and deep levels located near the buffer layer interface. (c) 2007 Elsevier B.V. All rights reserved.