Electrical activation of boron coimplanted with carbon in a silicon substrate

摘要

It is demonstrated that the electrical activation in B+(5.0×1014cm−2at 50 keV) implanted Si samples submitted to furnace annealing can be noticeably affected by a C+coimplantation. It was found that a C+dose ten times lower than that of B+is not sufficient to influence the activation behavior of B. However, C+implanted to a dose equal to or ten times higher than the B+dose contributed, respectively, to the reduction or enhancement of the electrical activation of B after annealing in the temperature range of 450–700 °C. In addition, the reverse annealing of B is attenuated in the coimplanted samples and suppressed in samples where the C+implantation damage was annealed prior to the B+implantation. At temperatures ≳700 °C the electrical activation is not significantly affected by the C+coimplantation. A model considering interaction between C and Si self‐interstitial atoms during thermal annealing is proposed to account for the activation behavior of B in the dually implanted samples.