MECHANICAL STRAIN AND DEFECTS IN THE END-OF-RANGE REGION IN SILICON IMPLANTED WITH GE-IMPLANTED WITH C+ IONS( AND CO)

Internal mechanical strain in (100) bulk Si implanted with 150 keV Ge ions at a dose of 2 x 10(15) cm(-2) and co-implanted with 65 keV C+ i ons over the dose range 3 x 10(13) to 1 x 10(16) cm(-2) has been inves tigated by double-crystal x-ray diffractometry. The crystal structure of the regrown implanted layers has been studied by plan view and cros s-section TEM. These investigations have shown that there is a source of strain at the depth of the end-of-range damage in the implanted and annealed crystals. The addition of C atoms in this region reduces the mechanical strain and eliminates the formation of the extended defect s. This effect is due to the trapping of Si interstitials by carbon at oms. It is speculated that strain compensation may also prevent the fo rmation of extended defects in the end-of-range region.