ACCEPTOR COMPENSATION IN SILICON INDUCED BY CHEMOMECHANICAL POLISHING

The acceptor compensation in polishing of p-type silicon with ammonia or amine-containing silica sol slurries has formerly been explained by the well-known inactivation of boron with atomic hydrogen or by the action of lattice self-interstitials. We give evidence by neutron activation analysis, energy-dispersive x-ray analysis, secondary ion mass spectroscopy and photoluminescence spectroscopy that traces of copper in the slurry are responsible for this effect. A mechanism for the chemomechanical polishing of silicon and the incorporation of copper into the wafer is suggested.