Local Structure of Ion-Bombarded a-Sic Analyzed by EXAFS

Abstract. X-ray absorption spectroscopy on the Si k-edge was performed on a-Sic (6H) to monitor the evolution of the local structure around the Si atoms after ion bombardment. The samples were irradiated by 50 keV Na ions at fluences of 10 "- 10 " ions/cma at a temperature of 80 K. EXAFS analysis clearly reveals that the hetero-atomic short range order of the crystalline matrix is almost completely conserved over the crystalline-to-amorphous transition as indicated by RBS-C. Further irradiation at higher fluences results in a change of the atomic coordination and formation of homonuclear Si-Si bonds.