Observations on the development of secondary defects in heavily damaged ion-implanted (100) and (111) silicon

Secondary defects produced by the annealing wafers of (100) and (111) silicon, implanted to a high dose (1016-l020 ions/cm3), were investigated using weak-beam electron microscopy. When annealed, the liquid-nitrogen multiple-voltage implanted (111) wafers showed a high density of faults, twins and dislocation tangles. Below this layer stacking fault tetra-hedra were found. This is the first report of their existence in ion-implanted silicon. A meandering perfect dislocation network was found in all (100) and (111) implants where the amorphous layer does not extend to the top surface. A model is proposed to explain these observations, based on the influence of stresses arising from damage on the defects nucleated at the crystalline “amorphous” interface.