Identification of the dissociative and kick-out diffusion mechanisms of Zn diffusion in GaAs by photoluminescence analysis

Abstract

Abstract Most investigations on Zn diffusion in GaAs were processed using the Zn–As alloy sources to prevent the As atoms from escaping GaAs wafers, while we found that the Zn diffusion would change fundamentally if Zn–Ga alloy sources were used. The Ga atoms from the diffusion sources suppressed the formation of the high-concentration surface region in Zn profiles, thus converting a kink-and-tail profile into a box profile. The photoluminescence (PL) analysis was used to identify the diffusion mechanisms. The Ga vacancy defects were found in the surface region of the kink-and-tail profile, indicating that the dissociative mechanism dominated; the PL spectrum in the tail region of kink-and-tail profile and the main region of box profile showed the same signals, no Ga vacancy defects were found, thus the kick-out mechanism dominated.