Study of the structural perfection and distribution/redistribution of silicon in epitaxial GaAs films grown by molecular beam epitaxy on (100), (111)A, and (111)B substrates

Silicon distribution before and after thermal annealing in thin doped GaAs layers grown by molecular beam epitaxy on (100)-, (111)A-, (111)B-oriented substrates is studied by X-ray diffraction and SIMS. The surface morphology of the epitaxial films inside and outside an ion etch crater that arises d uring SIMS measurements is studied by atomic force microscopy. Distinctions in the surface relief inside the crater for different orientations have be en revealed. Observed differences in the doping profiles are explained by f eatures of the surface relief developing in the course of ion etching in SI MS measurements and by enhanced Si diffusion via growth defects. (C) 2001 M AIK "Nauka/ Interperiodica".