Extensive ab initio calculations were performed for type-C defects on (001). Various models which were pertinent to sub-surface defects were studied. Substitutional B atoms in the second surface layer were predicted to be a possible atomic source of this type of defect. However, H and O - coupled with second-layer vacancies and substitutional C - were not expected to be responsible for type-C defects. The B in the second surface layer was spin-polarized and was expected to be sensitive to oxidation. It was structurally stiff and appeared to be metallic at high temperatures.

Atomic and Electronic Origins of a Type-C Defect on Si(001) T.Miyazaki, T.Uda, K.Terakura: Physical Review Letters, 2000, 84[18], 4128-31