Retardation of boron diffusion in silicon by defect engineering
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By judiciously placing vacancy and interstitial defects at different depths, we are able to enhance or retard boron diffusion. This opens up a new approach for the formation of shallow P+n junction in silicon. After preimplantation with 50 or 500 keV Si+ions to produce a surface vacancy-rich region, we studied the diffusion of deposited B on predamaged samples with annealing between 900 and 1010°C. Boron diffusion retardation was observed in both implantation conditions after low temperature annealing with enhancement occurring in a 50 keV implanted sample at high temperature. Choosing high energy implantation to separate vacancies and interstitials can reduce the boron diffusion significantly. Such suppression became more obvious with higher implant doses. A junction less than 10 nm deep (at 1 × 1017cm-3according to carrier concentration profiles) can be formed. © 2001 American Institute of Physics.
author list (cited authors)
Shao, L., Lu, X., Wang, X., Rusakova, I., Liu, J., & Chu, W.