The method of Rutherford backscattering spectrometry in combination with channelling was used to study the accumulation of structural defects in Si at room temperature as a result of irradiation with P+ and F+ atomic ions and also with cluster PFn+ ions (n = 1, …, 4) with the energy of 2.1keV/amu and with identical generation rate of primary defects. The conditions for correct comparison of the results of bombardment with atomic and cluster ions composed of atoms of various types were suggested. It was found that the characteristics of accumulation of structural defects in Si in the case of bombardment with PFn+ cluster ions differ widely from those under irradiation with both atomic ions that were involved in the cluster ion (P+ and F+) and with atomic heavy ions that had atomic mass close to that of the mass of a PFn+ cluster. It was shown that, with irradiation conditions being the same, cluster ions produce much more radiation defects in the surface region than do atomic ions; i.e., a molecular effect was observed. Plausible mechanisms of this phenomenon were considered.

Accumulation of Structural Defects in Silicon Irradiated with PFn+ Cluster Ions with Medium Energies. A.Y.Azarov, A.I.Titov: Semiconductors, 2007, 41[1], 5-10