High-density G-centers, light-emitting point defects in silicon crystal

Abstract

We propose a new method of creating light-emitting point defects, or G-centers, by modifying a silicon surface with hexamethyldisilazane followed by laser annealing of the surface region. This laser annealing process has two advantages: creation of highly dense G-centers by incorporating carbon atoms into the silicon during heating; freezing in the created G-centers during rapid cooling. The method provides a surface region of up to 200 nm with highly dense carbon atoms of up to 4 × 1019 cm−3 to create G-centers, above the solubility limit of carbon atoms in silicon crystal (3 × 1017 cm−3). Photoluminescence measurement reveals that the higher-speed laser annealing produces stronger G-center luminescence. We demonstrate electrically-driven emission from the G-centers in samples made using our new method.