GENERATION OF MISFIT DISLOCATIONS IN ULTRA-THIN SEMICONDUCTOR-FILMS

The lattice structure of thin films of GaP an GaAs has been studied for thicknesses around the critical value for the generation of misfit dislocations. Atomic layer molecular beam epitaxy was used for growth at low temperatures, on flat surfaces, and with accurate in-situ measurement of thickness. TEM images show surprisingly uniform distributions of misfit dislocations for thickness above 6 monolayers of GaP. A diffusionless, long-range cooperative mechanism is proposed for the relaxation process.