ANNEALING OF GAAS/ALAS SUPERLATTICES

A 60 nm GaAs/AIAs superlattice has been annealed under a variety of conditions. In the case of samples annealed in an arsenic rich atmosphere, the disordering of the superlattice was observed to be non-uniform. This non-uniformity of the disordering is in contrast to the observed disordering of the sample annealed under arsenic dissociative pressure. In this case the disordering of the superlattice was uniform throughout the sample. Until now evidence for the depth dependency of the interdiffusion process relied solely on the interpretation of photoluminescence results. The data obtained from these experiments clearly indicate that the interdiffusion of GaAs/AIAs superlattices cannot be represented by one interdiffusion coefficient, as proposed by Tan and Gosele. In addition, it is demonstrated that the interdiffusion coefficient presented by Tan and Gosele overestimates the true interdiffusion coefficient at 1000° C. © 1990 Chapman and Hall Ltd.