DIAGNOSING THE BUFFER LAYERS OF MULTILAYER EPITAXIAL STRUCTURES OF GAAS BY A PHOTOLUMINESCENCE METHOD

This paper describes the photoluminescence spectra (T=77 and 4.2 K) of multilayer epitaxial GaAs structures grown on a semi-insulating subst rate. A comparative analysis of the concentration of background impuri ties and defects in the high-resistance buffer layers is carried out b y analyzing their conductivity. It is shown that a photoluminescence m ethod can be used to diagnose the buffer layers. The main criterion fo r the perfection of the layers is that they do not contain the rather deep impurity and structural defects of type D-V-Ga, Ga-As (D-V-GA), V -As-Zn-Ga, and V-As-Si-As (D is a donor-type defect) that are responsi ble for the photoluminescence bands with emission peaks at 1.20, 1.32, 1.35, 1.38, and 1.41 eV,respectively. (C) 1996 American Institute of Physics.