Alpha-elastic recoil detection analysis of the energy distribution of oxygen ions implanted into silicon with plasma immersion ion implantation

Plasma immersion ion implantation was used to implant oxygen ions into silicon with applied voltage pulses of -40 kV and 2.5 mu s length. Positive ions, O-2(+) and O+, with a continuous energy distribution between O and 40 keV were implanted. Between 3x10(4) and 3x10(5) pulses, corresponding to nominal doses from 2x10(16) to 2x10(17)/cm(2), were used. The resulting oxygen depth profiles were measured with elastic recoil detection analysis using 13.4 MeV alpha particles. Rutherford backscattering was used to determine possible co-implanted contaminants. The obtained depth profiles were simulated using a linear superposition of calculated single-energy profiles. The results obtained for the energy distribution of the incident ions are compared with calculations obtained from a theoretical model, and the agreement is very good. The incident flux is found to be composed of 34(5)% O-2(+) and 66(5)% O+ ions with an Fe contamination of similar to 0.5%. (C) 1997 American Institute of Physics.