ARSENIC PRESSURE-DEPENDENCE OF GROUP-III ATOM INTERDIFFUSION IN GAAS-ALAS SINGLE-WELL HETEROSTRUCTURES

Annealing experiments were performed on undoped GaAs-AIAs single well heterostructures grown by MBE. The annealing experiments were performe d in evacuated and sealed silica ampoules. The temperature and time of annealing were fixed at 1000 degrees C and 4 h respectively while the As vapour pressure in the ampoules was varied from dissociative press ure to approximately 1.08 x 10(5) Pa. Compositional profiles were obta ined using dynamic SIMS. It was found that the amount of intermixing i n the layers was dependent both on As pressure and distance from the s ample surface. In contrast with previous results, the complex variatio n of interdiffusion with AS pressure observed in this work cannot be i nterpreted in terms of interdiffusion via group III vacancies and inte rstitials only.