The effect of implantation of P ions on the photoluminescence of Si nanocrystals in SiO2 layers

The effects of implanting 10¹³–10¹⁶ cm^?2 P ions and subsequent annealing at 600–1100°C on the photoluminescence of Si nanocrystals formed preliminarily in SiO₂ layers were studied. Quenching of the 780-nm luminescence band related to nanocrystals was observed immediately after the implantation of 10¹³ cm^?2 P ions. The recovery of emission from partially damaged nanocrystals was noticeable even after annealing at 600°C; however, heat treatments at 1000–1100°C were needed when the amorphization-threshold dose was exceeded. Intensification of luminescence was observed as a result of heat treatments of SiO₂ layers implanted with low doses of P ions; if the P content was higher than ～0.1 at. %, the recovery of luminescence was promoted. The former effect is attributed to impact crystallization of nanoprecipitates. The latter effect is attributed to the promotion of crystallization by an impurity and (along with the dose dependence of postannealing luminescence) is considered an indication that P atoms penetrate into the Si nanocrystals. Contrary to a number of estimations, introducing P does not result in the quenching of luminescence due to Auger recombination. This discrepancy is attributed to the interaction of charge carriers with the nuclei of donors.