Effects of cluster carbon implantation at low temperature on damage recovery after rapid thermal annealing

Cluster C implantation at low temperature has been studied in terms of amorphous Si (a-Si) formation and elimination of B implanted induced end of range defects (EORDs). Thickness of a-Si can be controlled by C equivalent energy and dose. Monomer C never creates a-Si layer at less than 1E15/ cm² at 25°C implant. Dose increase and temperature decrease starts to create a-Si layer. On the other hand, cluster C7 implant creates a-Si layer at less than 5E14/cm² dose even at 25°C, and -30°C implant increases the a-Si thickness by around 7~8nm in each C dose. A large amount of EORDs remain in cluster B10 25°C implant sample after RTA at 950°C. The situation does not change a lot with B10 -30°C implant. On the other hand, cluster C7 co-implant with B10 at 25°C, however, greatly reduces EORD density. EORD free can be realized in C7 co-implant with B10 at -30°C. Cluster C7 co-implant at -30°C assists the EORD elimination. Sheet resistance of cluster C and B10 co-implanted at -30°C sample is remarkably low compared with only B10 implanted sample. It can be concluded that cluster C implantation at -30°C is very effective for eliminating EORDs and obtaining high carrier activation.