A study of vacancy-type defects introduced by the carburization of Si by monoenergetic positron beams

Vacancy-type defects introduced by the carburization of Si were studied by means of monoenergetic positron beams. Doppler broadening spectra of the an nihilation radiation were measured for Si substrates with carbon films at t emperatures between 298 and 1473 K. The line-shape parameter S, which corre sponds to the annihilation of positrons near the interface between the carb on film and the Si substrate, started to increase above 1173 K. This was at tributed to the trapping of positrons by vacancy-type defects introduced by carburization. The major species of the defects detected by positron annih ilation was identified to be vacancy clusters in the Si substrate. (C) 2001 American Institute of Physics.