Effect of amorphization and carbon co-doping on activation and diffusion of boron in silicon

We investigate the impact of amorphization and C co-implantation on B diffusion and activation properties after conventional spike rapid thermal annealing (RTA). We observe that after complete recrystallization at 600 degrees C the B tail deepens by 5 nm (at 5x10(18) at./cm(3)) due to B diffusion in a-Si. After spike RTA it becomes 12 nm deeper with respect to an as-implanted profile, which proves that both diffusion mechanisms in a-Si and c-Si are important. However, the B diffusion in c-Si is sensitive to the fraction of substitutional C incorporated into c-Si. The best junction depth is X-j=16.5 nm, with abruptness of 2 nm/decade and R-s=583 Omega/square. (c) 2006 American Institute of Physics.