Ion Implantation and Synthesis of Materials - Studium

3 Dynamics of Binary Elastic Collisions3.1 IntroductionIn ion beam modification of materials, the energetic ions interact with the solidthrough atom interatomic potential. These interactions are the basis of thedevelopment of expressions for ion range and ion damage in solids. Consider thepassage of an energetic ion in a solid during an ion implantation experiment(Fig. 3.1). As the ion travels through the solid, it undergoes collisions with thestationary target atoms, which deflect the ion from its initial direction. The ionalso collides with electrons in the solid and loses energy in these collisions. Themajor changes in its flight direction are due to the ion's collision with individuallattice atoms. This chapter will focus on two-body collisions, or binary collisions,involving energetic ions and target atoms.r 1r 2Ion StopsR pTarget SurfaceFig. 3.1. The passage of an energetic ion in a solid during an ion implantation experiment,showing the total ion path and the projected range, R p . As the ion travels across the solid, itundergoes collisions with stationary target atoms, which deflect the ion from its initialdirection23