Multispecies nitrogen diffusion in silicon

Outdiffusion profiles of nitrogen, produced by 900 degrees C annealing and monitored by secondary ion mass spectroscopy, clearly show that the nitrogen community consists of three noninteracting components. The A component (dominant at higher nitrogen concentration) is represented by a species that outdiffuses by the dissociation mechanism. The B component (the only one at lower nitrogen content) exists mostly in a precipitated form. The C component is an independent outdiffusing species. The A component can be assigned to one of the even-sized species: N-2, N-4, or N-6. The most likely assignment, free of controversies, is to hexamers N-6 transported by dissociation into minor fast-diffusing trimers N-3. The B component, in its dissolved form, is then assigned to the N-2/N-1 subsystem of immobile dominant dimers and fast-diffusing minor monomers. For the C component, a tentative assignment is to N-4 or N-5.