The implantation of Be ions into heterostructures at room temperature or liquid N temperatures was investigated. It was found that room-temperature implantation created dislocation loops at the first interface; a distance which was far short of the maximum projected range. Implantation at low temperatures caused twinning. The latter could be removed by annealing (900C, 1200s), without leading to the interdiffusion of Al. The presence of dislocation networks tended to enhance intermixing. The Be concentrations were sufficiently low to prevent Be-induced intermixing.

S.Mitra: Semiconductor Science and Technology, 1990, 5[11], 1138-40