Formation and Properties of Three Copper Pairs in Silicon

摘要

Copper in silicon is a feared contaminant in device processing. It diffuses quickly as an interstitial and forms electrically active precipitates that are difficult to dissolve. Several complexes assigned to copper pairs have been observed but have yet to be unambiguously identified and fully characterized. We present the results of joint theoretical-experimental studies of several pair structures. The theoretical work involves ab-initio molecular-dynamics simulations, and the results include configurations, binding energies, electronic structures, vibrational modes and formation dynamics. The experimental work combines electrical and optical techniques. One characteristic of the photoluminescence spectra is the presence of phonon replicas that imply the existence of very similar low-frequency and localized vibrational modes in two distinct copper pairs. These modes are theoretically identified.