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Decoration of nitrogen vacancies by oxygen atoms has been studied by near-edge X-ray absorption fine structure (NEXAFS) around B K-edge in several boron nitride (BN) structures, including bamboo-like and multi-walled BN nanotubes. Breaking of B-N bonds and formation of nitrogen vacancies under low-energy ion bombardment reduces oxidation resistance of BN structures and promotes an efficient oxygen-healing mechanism, in full agreement with some recent theoretical predictions. The formation of mixed O-B-N and B-O bonds is clearly identified by well-resolved peaks in NEXAFS spectra of excited boron atoms.

Hydrogen implantation and subsequent thermal annealing is found to result in a well-defined band of cavities in Si. This band is an extremely efficient gettering layer for Cu which is also introduced into the near surface of Si by ion implantation. Profiling of implanted Cu indicates that ∼95% of an initial 3×1015 cm−2 Cu implant is redistributed following annealing at a temperature of 780 °C from a near-surface damaged layer to a narrow band of cavities of width ∼1000 Å at a depth of ∼1 μm. Furthermore, the Si between the surface and the cavity band is essentially defect-free and that some cavities contain the bulk Cu3Si phase.

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Formation of defects in hexagonal and cubic boron nitride ͑h-BN and c-BN, respectively͒ under low-energy argon or nitrogen ion-bombardment has been studied by near-edge x-ray absorption fine structure ͑NEXAFS͒ around boron and nitrogen K-edges. Breaking of B-N bonds for both argon and nitrogen bombardment and formation of nitrogen vacancies, V N , has been identified from the B K-edge of both h-BN and c-BN, followed by the formation of molecular nitrogen, N 2 , at interstitial positions. The presence of N 2 produces an additional peak in photoemission spectra around N 1s core level and a sharp resonance in the low-resolution NEXAFS spectra around N K-edge, showing the characteristic vibrational fine structure in high-resolution measurements. In addition, several new peaks within the energy gap of BN, identified by NEXAFS around B and N K-edges, have been assigned to boron or nitrogen interstitials, in good agreement with theoretical predictions. Ion bombardment destroys the cubic phase of c-BN and produces a phase similar to a damaged hexagonal phase.