Optical properties of ion-implanted silicon and separation by implantation of oxygen silicon-on-insulator substrates in the infrared: Study of B+ and P2+ implantation doping

The optical properties of ion implanted silicon and silicon-on-insulator substrates have been studied by Fourier transform infrared spectroscopy. The influence of the implanted-ion mass in changing the refractive index of a silicon target has been examined by implanting 80 keV 11B+ and 62P2+ ions respectively. A refractive index rise not exceeding 2% and total amorphization were observed respectively in the vicinity of the Si surface after boron and phosphorous implantations. Free carrier profiles generated after thermal annealing at 950 oC/30 min and 1150 oC/120 min were modeled by Pearson and half-Gaussian distributions respectively. The phosphorous implantation was also performed in silicon-on-insulator substrates, yielding after annealing nearly homogeneous free-carrier profiles in the top-Si layer and optical mobility values comparable to those of bulk-Si.