Ion-channeling analysis of boron clusters in silicon

We have measured axially channeled Rutherford backscattering spectra of Si1 -xGex nanofilms in silicon(001). A step in the yield of the host crystal wa s found for off-normal axes at the depth of the nanofilm. The step was meas ured as a function of the angle between the incoming beam and the [011] axi s and shows two maxima. It is found that Monte Carlo simulations assuming t etragonal distortion reproduce the experimental results. A universal curve was derived which enables determination of the tetragonal distortion from i on-channeling experiments, for a given film thickness. The results are comp ared with XRD measurements. (C) 2001 American Institute of Physics.