Vacancy-type defects in electroless Cu were investigated using both positron annihilation technologies and secondary ion mass spectroscopy. The density of vacancy-type defects in electroless Cu was greater than that in electrolytic Cu. The defects were vacancy–impurity complexes; the open volume of such defects was similar to that of superposition of small vacancy clusters and divacancy. No other major vacancy-type defect was observed at the interface between electroless Cu and the subsequent electrolytic Cu.

A Study on Vacancy-Type Defects in the Electroless Cu Measured with a Monoenergetic Positron Beam. K.Yamanaka, A.Uedono: Scripta Materialia, 2009, 61[1], 8-11