Range parameters of deep ion implants in group IV semiconductors

Ions of selected elements of the periodic system were implanted into amorphous layers of C, Si and Ge with specific energies of up to 1 MeV/amu. The resulting profiles were measured with specific nuclear reactions (A1 < A2) and Rutherford backscattering (A1 > A2) up to depths of 10 μm. In all cases, the first and second range moments of the concentration profiles were determined as a function of implantation energy, whereas both the next two higher moments could be derived only in those cases where the complete ion distribution was measurable down to the surface position. Here, for a few typical examples, also lateral distributions, by measuring implants with varied angle of incidence, were obtained and analyzed with respect to the first two even lateral moments. The results of a detailed comparison of the range parameters are discussed in terms of scaling properties within the framework of LSS theory. As regards the projected ranges predicted by TRIM calculations, significant deviations from our experimental values occur within the interval of +20% and -60%. These discrepancies are attributed to the electronic stopping powers used by the TRIM program. (orig.)