Hydrogen, fluorine ion implantation effects on polycrystalline silicon grain boundaries

The influences of hydrogen and fluorine ion implantation on polycrystalline silicon (poly-Si) grain boundaries have been investigated. Effective passivation of poly-Si grain boundaries was achieved by hydrogen ion implantation at 300–400°C. From fluorine implantation experiments, we confirmed that fluorine atoms in poly-Si were redistributed with a diffusion tail after annealing at above 600°C. A diffusion tail of fluorine redistribution was not observed in single crystalline silicon. We think that it is possible to passivate poly-Si grain boundaries by controlling the diffusion of fluorine.