Boron segregation in As-implanted Si due to electric field and transient enhanced diffusion

Boron segregation toward implanted arsenic profile in Si during annealing was investigated under various annealing conditions. It is found that both the implant damage created by the arsenic implantation and arsenic deactivation enhance the diffusion of the embedded boron layer toward the shallow As implanted profile. This phenomena was found in both 650 degree Celsius furnace annealed (FA) and 1000 degree Celsius rapid thermally annealed (RTA) samples. For the 650 degree Celsius FA sample, the boron segregation peak was found located at the junction formed by implanted As, where residual dislocation loops at the original amorphous/crystalline (A/C) interface was also observed. However, no A/C interface dislocation loops were found to be present for the RTA samples. Additional anomalous boron segregation was observed for the 1000 degree Celsius RTA plus 750 degree Celsius FA samples. The additional boron segregation is not correlated with defect layers. It is, therefore, concluded that the anomalous boron segregation is caused by the electric field resulting from the formation of p-n junction.