Nickel segregation on dislocation loops in implanted silicon

Segregation of Ni was observed by atom probe tomography at the edges of a pseudo-hexagonal dislocation loop within As+-implanted (0 0 1) Si wafers, after Ni deposition but before heat treatment. Thanks to crystallographic information retained within the atom probe tomography data, the orientation of the loop was determined to be within the {1 1 1} plane and elongated along the <11¯0> direction. The presence of pseudo-hexagonal dislocation loops was confirmed by transmission electron microscopy. Concentrations of more than 10 at.% in Ni were measured at the edges of the loop.