Electron traps in dislocation-free In-alloyed liquid encapsulated Czochralski GaAs and their annealing properties

Abstract

Electron traps in dislocation-free In-alloyed liquid encapsulated Czochralski (LEC) GaAs have been studied by deep level transient capacitance spectroscopy. Five traps are observed with activation energies ranging from 0.26 to 0.79 eV below the conduction band. The energies are closely equal to the ones observed in undoped LEC GaAs. However, a notable difference between the In-alloyed crystal and the undoped crystal exists in effects of annealing on the deep levels. For the In-alloyed crystal, all levels except EL2(0.79 eV) are unstable under the annealing at 850 °C, while for the undoped crystal, levels EL5(0.41 eV) and EL2 remain stable.