Ion beam induced epitaxy experiments in silicon under channeling and random alignments

This paper examines issues arising in ion beam induced epitaxial crystallisation (IBIEC) of both surface and buried amorphous silicon layers at 320°C under random and channeled alignment of MeV C⁺ beams. These issues include: random versus channeled energy loss, multiple scattering in amorphous layers, direct displacement versus cascade effects on IBIEC and Rutherford backscattering depth scales. Multiple scattering within amorphous layers and channeled energy loss for MeV He⁺ and C⁺ beams were directly measured using Rutherford backscattering/channeling (RBS-C) and markers. When the above issues were taken into account the IBIEC measurements indicated that epitaxial growth is stimulated by silicon displacements very close to the amorphous-crystalline interface. However, effects in buried amorphous layers show that displacements at the interface due to cascades rather than primary ion displacements play a major role in determining random versus channeled behaviour.