Redistribution of deep levels in semi-insulating GaAs wafer by rapid thermal processing

Abstract

The distributions of deep levels in semi-insulating GaAs before and after rapid thermal processing (RTP) at 800 °C are obtained by the contactless measurement of the optically injected excess carrier signal height by reflectance microwave prober method. The deep levels in the liquid-encapsulated Czochralski-grown 2 in. GaAs wafer are redistributed by RTP, and its spatial variation shows a W-shaped pattern along the 〈100〉 radial direction. Furthermore, the distribution of deep levels in the RTP wafer corresponds to the crystallographic slip generation pattern, which is relief of the thermal stress during RTP, examined by x-ray topography. The redistribution of the deep levels is due to the production of the principal deep level EL2 by RTP.