Effects of Additional Vacancy-Like Defects Produced by Ion Impealations on Boron Thermal Diffusion in Silicon
- Received Date: 2004-12-27
- Accepted Date: 1900-01-01
- Available Online: 2005-11-05
Abstract: The effects of additional vacancy-like defects on thermal diffusion of B atoms in silicon were investigated by using secondary ion mass spectroscopy. B atoms were introduced into silicon by 30keV B ion implantation at a dose of 2×1014cm-2, while the additional vacancy-like defects were produced by two different ways. One was via 40 or 160keV He ion implantation at a dose of 5×1016cm-2 and followed by an annealing at 800°C for 1h, which produced a well-defined cavity band near the projected range of He ions. The other was via 0.5MeV F or O ion implantation at a dose of 5×1015cm-2,which creates excess vacancy-like defects around the 1/2 projected range of F or O ions. Our results clearly show that the additional vacancy-like defects could suppress the boron diffusion during subsequent thermal annealing at 800°C for 30 min. The suppressing effects were found to depend on both the ion type and ion energy. The results were qualitatively discussed in combination with the results obtained by using transmission electron microscopy and Rutherford backscattering spectroscopy.