NATIVE POINT-DEFECTS IN SI WITH A COSI2 FILM - SINGLE-CRYSTAL VERSUS POLYCRYSTALLINE

We have determined the native point defects concentrations in silicon with single and polycrystalline CoSi2 films by annealing Sb and B dopi ng superlattices at 850 degrees C/60 min in N-2. The polycrystalline f ilm results in enhanced Sb diffusion in Si, indicating a vacancy super saturation (C-V/C-V)similar to 2.4+/-0.8, while the single crystal fi lm maintains a vacancy concentration near equilibrium. Boron diffusion is retarded by the same amount by both films, indicating an interstit ial undersaturation (C-I/C-Isimilar to 0.3+/-0.1). This directly impl ies that CoSi2 grain boundaries are the cause of the higher vacancy su persaturation that is well known to occur during standard Co silicidat ion.