Study of grown-in defects and effect of thermal annealing in Al0.3Ga0.7As and GaAs LPE layers

Abstract

Studies of the grown-in deep-level defects in the undoped n-AlxGa1-xAs (x = 0.3) and GaAs epitaxial layers prepared by the liquid phase epitaxy (LPE) techniques have been made, using DLTS, I-V and C-V measurements. The effect of 300 °C thermal annealing on the grown-in defects was investigated as a function of annealing time. The results showed that significant reduction in these grown-in defects can be achieved via low temperature thermal annealing process. The main electron and hole traps observed in the Al0.3Ga0.7As LPE layer were due to the Ec-0.31 eV and Ev+0.18 eV level, respectively, while for the GaAs LPE layer, the electron traps were due to the Ec-0.42 and 0.60 eV levels, and the hole traps were due to Ev+0.40 and 0.71 eV levels.