Room-temperature evolution of vacancy-type damage created by 2 keV B+ implantation of Si

Beam-based positron annihilation spectroscopy has been applied to the study of near-surface vacancies created by 2 keV B+ ions implanted into Cz Si. The use of a controllable-energy positron beam means that the probe can be tuned to maximize the response to the subsurface damage. Time-dependent changes have been observed in the near-surface vacancy concentration profile. For example, after one week at room temperature, exposure of an implanted sample to white light for 1 h resulted in the migration of ∼95% of the measurable damage to sinks—primarily, it is assumed, to the surface. The relative importance of temperature, air, and light has been investigated.