Trapping centers in heavy ion irradiated silicon

Low fluence heavy ions incident on high resistivity Si produce lattice defects which act as trapping centers, and produce also an important local field of strain. The strain field intensity increases with the increase of the difference in atomic size and mass between the ion and the Si atom host. We investigate the correlation between the change of trapping parameters and the strain field. The strain field produced by Bi ions in Si is two times more intense than in Si irradiated with I ions, and effects the Gaussian broadening of trapping levels and the temperature dependence of cross sections.