Mapping the Uniformity of Deep Level Defects Distribution by Scanning Photoluminescence

Deep level defects in undoped semi-insulating GaAs were investigated by photo-luminescence technique at room temperature. The 0.69eV band is associated with the main mid-gap level EL2, and the 0.76eV band is suggested to be caused by some native point defects related to excess As, such as As anti-site defect. Two-dimensional and pseudo three-dimensional plots of the EL2 related band have been observed for as grown and annealed wafers.