COMPARISON OF THE EFFECTS OF ION-IMPLANTATION INDUCED INTERDIFFUSION IN GAAS/ALGAAS AND INGAAS/GAAS SINGLE QUANTUM-WELLS

Implants of arsenic and gallium ions have been made into InGaAs/GaAs and GaAs/AlGaAs single quantum wells to a dose of 10(13) atoms/cm2. In each case the implantation energies are varied so as to get the peak of the implantation profile at the centre of the well. Using repetitive anneals and photoluminescence from the n = 1 electron to heavy hole transition, it has been possible to follow the evolution of the diffusion coefficients for the interdiffusion with anneal time. Following gallium implantation no effect was observed on the diffusion coefficient for intermixing in either material system. However, a region of very rapid intermixing which occurred either during implantation or the first anneal was seen in both materials. This is attributed to either radiation enhanced diffusion or the movement of interstitials created by the ion beam. Following arsenic implantation, the GaAs/AlGaAs material behaved identically to the gallium implanted samples. The InGaAs/GaAs materials, however, showed a region of intermixing where the diffusion coefficient was enhanced by an order of magnitude before returning to approximately the unimplanted control value.