Samples were implanted with 0.55 to 2MeV Er ions at 350C, and were studied by using Rutherford back-scattering and channelling spectroscopic techniques. Angular scan profiles through the <110> and <100> channels, recorded in the (100) plane, were measured. In particular, the angular scan profiles for Er indicated that the flux peaked in the <110> channel. This suggested that the Er atoms were located mainly in the middle of the <110> channel; corresponding to hexagonal interstitial positions. Monte Carlo simulations were performed for the assumed hexagonal interstitial locations of the implanted Er atoms. They reproduced well the experimentally determined back-scattering spectra and angular scan profiles. It was also shown that annealing at 600C resulted in an increase in the hexagonal interstitial fraction. Additional short-term annealing at 900C led to the precipitation of an Er-Si phase, and an associated marked increase in the back-scattering yield from the Er-doped layer.

A.Kozanecki, J.Kaczanowski, R.Wilson, B.J.Sealy: Nuclear Instruments and Methods in Physics Research B, 1996, 118[1-4], 709-13