Metastable CuVO* Complex in Silicon

Abstract

The reaction of the mobile interstitial Cui atom and the A-center (vacancy-oxygen complex) was recently reported to produce at 350 K the rather stable CuVO complex. Chemomechanical polishing in a copper-contaminated slurry allowed to lower the copper in-diffusion temperature down to 295K. The development of the CuVO complex is shown to proceed via formation of the metastable precursor (CuVO*) which introduces two deep levels in the lower half of the band gap. The CuVO* defect is unstable at room temperature and transforms completely into the CuVO complex by a 30 min anneal at 350 K. The proposed structure for the CuVO* complex of a Cui atom trapped nearby the A-center is supported by recent ab-initio calculations.