Abstract

We present the first impact ionization investigation by electroluminescence of InxAl1-xAs /InxGa1-xAs metamorphic High Electron Mobility transistors on GaAs. Two Indium content are investigated. First we observe the decrease of the detrimental effect of impact ionization with the decrease of the Indium content. Second, the electroluminescence measurements illuminate the functional relationship between impact ionization and the kink effect. In these metamorphic HEMT’s, we suggest that both kink effect and impact ionization threshold are originated to detrapping process of deep levels in the large band gap layer.