Blocking- and channeling-ERDA with heavy ions

Abstract

A 2-dimensional position sensitive ionization chamber was used for structural analysis of single crystalline materials by blocking- and channeling-ERDA. Radiation damage of swift heavy ions in Ge was measured by blocking-ERDA. Clear indications of annealing effects with increasing electronic stopping power were found. A transition from blocking to channeling behavior was observed for recoils from larger depth in measurements on single crystalline Si. Capture to channeling is shown to be a general phenomenon for ions with large energy loss in additional experiments on thin Si membranes. The large solid angle of the ionization chamber is advantageous in channeling-ERDA to minimize radiation damage. The position sensitivity was used in this application to align the desired crystalline direction. The lattice strain of buried CoSi 2 layers in (100) Si was measured by channeling-ERDA. The corresponding angular shift could be separated from the steering effect due to the small critical angles of high energy heavy ions. These examples demonstrate the increased potential of ERDA when channeling or blocking conditions are used.