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.