Interface structure evolution and impurity effects during solid-phase-epitaxial growth in GaAs

The time-resolved reflectivity technique is shown to be able to characterize interface structure during solid-phase epitaxy in GaAs. A detailed study of interface structure during regrowth and recrystallization kinetics is made for different implanted impurities and implantation parameters in GaAs. It is shown that the interface roughens on a macroscopic scale during the regrowth process and that this evolution has an intrinsic character in the implanted material. Activation energy is shown to be independent of implantation conditions. Substitutional impurity implantation does not produce variations in regrowth kinetics whereas argon implantation drastically decreases the growth rate. Results are interpreted in terms of interface roughening due to nonrelaxing atomic configurations in the disordered phase. The evolution of the interface has been related to an increase of disorder in the regrown layers.