Photoluminescence study of radiative channels in ion-implanted silicon.

Abstract

Efficient radiative defects are introduced in boron-doped silicon by carbon- and oxygen-ion implantations and subsequent annealing up to 500 \ifmmode^\circ\else\textdegree\fi{}C. They exhibit sharp and intense low-temperature photoluminescence transitions in a range between 767.0 meV (P line) and 1080.0 meV (Y line). From correlations between the line intensities and the oxygen and carbon contents in the samples, it is argued that the P center and the H center (925.4 meV) are carbon- and oxygen-related defects. The L line (1003.8 meV) is influenced by carbon, and it appears to be independent of oxygen. The X line (1040.0 meV) and the W line (1018.0 meV) are attributed to centers that are formed from intrinsic point defects. The generation and annealing of the G line (969.4 meV) and the C line (789.0 meV) in implanted Czochralski-grown material are reminescent of those in particle-irradiated silicon. However, for the G defect in implanted float-zone material, an alternative formation mechanism is proposed. Among the other observed photoluminescence lines, the two lines at 1101.4 and 1103.8 meV are reported here for the first time. The optical centers responsible for these two lines are tentatively suggested to involve oxygen and carbon.