X‐Ray Investigation of Lattice Deformations in Silicon Induced through High‐Energy Ion Implantation

Abstract

X-ray interference fringes observed in X-ray topographs of silicon crystals bombarded with high energy ions (dose > 10¹⁵ ions/cm²) are described. The X-ray fringes are used to analyze the deformation state of the crystal. It is shown that the bombarded crystal is a special kind of bicrystal composed of a thick perfect bulk crystal topped by a thin practically perfect layer crystal. Both crystals have the same crystallographic orientation and the same lattice constant but are separated by a small rigid body displacement. Contrast and geometry of the observed X-ray patterns agree with the theoretical patterns calculated by Bonse and Hart [1] on the basis of a layer/bulk bicrystal model, and are also supported through transmission electron microscopy results. The ion range calculated from the interference fringes is in good agreement with the experimentally determined range.