Ion channeling study of cavities in silicon formed by He implantation

Cavities formed by desorption of He implantation in Si are studied by Rutherford backscattering and channeling spectrometry. Whereas axial channeling is better to determine the depth profile of the defects, planar channeling is more suited to locate the position of the cavities. Measurements as a function of scattering angle show that a large scattering angle is more sensitive to reveal the lattice disorder. Energy-dependent dechanneling measurements indicate an energy-independent behavior in the depth region where only cavities are present. At larger depths, the dechanneling cross section is inversely proportional to the analysing energy.