Improvement of InP Crystal Quality on GaAs Substrates by Thermal Cyclic Annealing

Abstract

We have studied the effect of thermal cyclic annealing (TCA) on the crystal quality improvement of MOCVD grown InP on GaAs substrates. The crystal quality has been evaluated by the etch pit density (EPD), X-ray diffraction and photoluminescence (PL) measurement. It is found that the TCA is effective in reducing the dislocation density, and that the annealing at 700°C is essential to confine the point defects near the InP/GaAs interface. The EPD is reduced from 6×10 7 cm -2 to 3×10 7 cm -2 , and the defect-related PL peak intensity is decreased below the residual level in the 5 µm-thick InP on GaAs.