Fluorine-vacancy complexes in ultrashallow B-implanted Si

Shallow fluorine-vacancy FV complexes in Si have been directly observed using variable-energy positron annihilation spectroscopy and secondary ion mass spectrometry. The FV complexes, introduced to combat the deactivation and transient-enhanced diffusion of ultrashallow boron, were observed in preamorphized Si wafers implanted with 0.5 keV B and 10 keV F ions at a dose of 1015 cm−2, and then annealed isothermally at 800 °C for times ranging from 1 to 2700 s. The results are in agreement with a model which predicts that the complexes are of the form F3nVn, with n most probably being 1 and/or 2. © 2006 American Institute of Physics. DOI: 10.1063/1.2335594