Investigation of ion-implanted crystals by means of directional effects in charged particle reaction yields

Abstract

The paper describes a method for the study of ion-implanted crystalline materials. This method allows simultaneous investigations of the sites of the implanted atoms and of the damage of the substrate structure caused by the implantation. It is based upon the orientation dependence of charged particle reaction yields in single crystals. A short summary of the underlying theory is given, and the experimental procedure is discussed. The utility of the method is demonstrated in an investigation of implanted Fe and Si crystals. The results show a remarkable difference between Fe and Si as to the amount and distribution of the implanted ions and the damage. At a dose of 8 x 10 13 60 keV Sb ions/cm 2 , Si is completely disordered in a region corresponding to the range distribution, and the implanted ions cannot be assigned to well-defined sites. Fe is only moderately damaged after a dose of 2 x 10 16 150 keV Sn ions/cm 2 (which have about the same projected range in Fe as the 60 keV ions in Si), and ca . 85% of the implanted ions are on lattice sites. This result provides a direct explanation of the difference between implanted metallic and non-metallic Mössbauer samples.