Improvement of Crystalline Quality of Si Films on CaF2/Si Structures by Ion Implantation and Solid Phase Recrystallization

Crystalline quality of Si films grown on CaF2/Si heteroepitaxial structures has been improved by solid phase recrystallization of ion implanted amorphous layers. Both the Si/CaF2/Si(100) and Si/CaF2/Si(111) structures were bombarded with P+ ions to amorphize the surface region of the top Si films, and subsequently annealed at temperatures of 550–750°C. It has been found from ion channeling measurements that the crystalline quality of the Si films on CaF2/Si(100) structures is significantly improved after recrystallization at 750°C, but the quality of the Si films on CaF2/Si(111) structures is not improved by this method.