Movement of defects and atoms during ion beam induced crystallization

Depth dependence of ion beam induced epitaxial crystallization in Si has be en studied to investigate the diffusion of defects responsible for crystall ization. Regrowth rates for 3 MeV Au, 3 MeV Si and 5 MeV Au were measured b y ion channeling for different depths. Decreases in regrowth rates were cle arly observed near the surface (< 1000 Angstrom). Calculated damage profile s also decreased near the surface but the measured regrowth rates decreased more. Impurity oxygen atoms recoiling from surface native oxide partially contribute to the decrease at shallow regions below similar to 300 Angstrom . The decrease in regrowth rates at deeper regions suggests the long range diffusion of defects responsible for crystallization. (C) 2001 Elsevier Sci ence B.V. All rights reserved.