Vacancy-type defects, which were introduced by carburisation, were studied by using mono-energetic positron beams. The Doppler broadening spectra of annihilation radiation were measured for Si substrates, with C films, at between 298 and 1473K. The line-shape parameter which corresponded to the annihilation of positrons, near to the interface between the C film and the Si substrate, began to increase above 1173K. This was attributed to the trapping of positrons by vacancy-type defects that were introduced by carburisation. The major defect species which were detected by positron annihilation were vacancy clusters in the Si substrate.

A Study of Vacancy-Type Defects Introduced by the Carburisation of Si by Monoenergetic Positron Beams. A.Uedono, M.Muramatsu, T.Ubukata, M.Watanabe, T.Ichihashi, R.Suzuki, T.Ohdaira, T.Mikado, S.Takasu: Journal of Applied Physics, 2001, 89[7], 3606-10