Annealing temperature effects on the structure of ferromagnetic Mn-implanted Si

The dependence of the magnetization of Mn-implanted Si on the postimplant annealing temperature is studied. p-type Si wafers were implanted with 300 keV Mn+ ions at 350 degrees C to a fluence of 2 X 10(16) cm(-2) and then annealed at 500-900 degrees C for 5 min. Ferromagnetic hysteresis loops were obtained at 10 K using a superconducting quantum interference device magnetometer. The saturation magnetization increases with the postimplant annealing temperature, reaching an optimum field strength of 0.2 emu/g at 800 degrees C. An out diffusion of Mn is observed at higher temperatures that coincides with a decrease in the saturation magnetization. The calculated point-defect profile that was generated by the implantation process peaks around the Mn-depleted region, suggesting that the residual implant damage may play a role in the ferromagnetic behavior of Mn-implanted Si. (c) 2006 American Vacuum Society.