Influence of carbon on erbium lattice location in Si:Er

Abstract

AbstractThe 1.5 µm luminescence from Si:Er is known to strongly depend on impurities (e.g. carbon) in silicon. In this work, we investigate the effect of carbon co-doping on the lattice location of Er atoms in Si by Rutherford backscattering(RBS)/channeling techniques. A float-zone (FZ) Si (100) wafer was first amorphized to a depth of ~ 0. 3 µm by Si ions implanted to a dose of ~ 1×1015cm2 at liquid nitrogen temperature. Carbon ions were then implanted into the amorphous silicon, which was recrystallized via solid phase epitaxial growth (SPEG) at 600°C following C implant. Finally Er ions were implanted into the C-doped and C-free Si crystals, with the substrate temperature at 25°C and 300°C respectively. The RBS/channeling results show that the Er redistribution and Si crystallinity are strongly affected by C co-doping. The incorporation of C into Si can significantly suppress Er surface segregation, and modify the lattice location of Er atoms in Si. We discuss these effects in terms of the formation of Er-C defect complexes.