Surface properties of hydrogen-implanted SrTiO3 using high energy ion scattering techniques

Full text: The near-surface region of single crystals may be transformed into partially or fully amorphous material with significant changes in properties during the ion implantation process. There is a renewed interest in the use ion implantation to alter the near-surface properties of SrTiO3 due to the current activities in the semiconductor industry. We have investigated the surface structure and the type of defects in clean and hydrogen irradiated SrTiO3(001) using high energy ion backscattering and channelling (HEIS) techniques. A SrTiO3(001) sample was irradiated with 40 keV H ions at 120 K with an ion fluence of 7.5x1016 atoms/cm2 at Implant Sciences Corporation. High energy ion backscattering and channeling spectrum including angular yield curves were measured from the virgin and hydrogen implanted regions using 1.0 - 3.0 MeV He+ ions at the Environmental Molecular Sciences Laboratory (EMSL). The defect dechanneling factors were calculated for the virgin and irradiated regions using the critical angles determined from the angular yield curves. The dependence of the defect dechanneling parameter on the incident energy was investigated and it was observed that the generated defects are mostly interstitial atoms and amorphous clusters. Ion scattering simulations were performed using the VEGAS code and were compared with experimental results. Computer simulations of the experiment for the clean surface show good agreement with the experimental data