Effects of amorphizing species' ion mass on the end-of-range damage formation in silicon

The effects of preamorphizing ion mass on the end-of-range (EOR) damage and subsequent enhanced diffusivity have been investigated. Amorphizing silicon with implants of 22 keV Si-28(+), 32 keV Ge-73(+), 40 keV Sn-119(+), and 45 keV Pb-207(+) provided the mass comparisons. Cross-sectional transmission electron microscopy analysis showed that the amorphous layer depths were approximately 400 A. After postimplantation annealing at 750 degreesC for 30 min, plan-view transmission electron microscopy (PTEM) revealed that increasing the ion mass decreased the defect size and density. Quantitative analysis of PTEM results also showed that increasing ion mass decreased the population of interstitials trapped in the EOR. Secondary ion mass spectrometry depth profiles of grown-in boron marker layers showed that increasing the ion mass decreased the time average diffusivity enhancements of boron (<D-B>/D-B(*)). (C) 2002 American Institute of Physics.