The effect of As doping upon P diffusion in Si was studied by using first-principles calculations. It was found that a form of As-vacancy complex was energetically favourable; allowing As to consume the vacancy so as to prohibit vacancy-mediated P diffusion. Also, in the vicinity of As, the vacancy-mediated P diffusion barrier was increased, further decreasing the P mobility. The results provided useful guidance for designing As-doped barriers to block P diffusion in Si wafer processing and metal oxide semiconductor field-effect transistor device fabrication.

Confining P Diffusion in Si by an As-Doped Barrier Layer. L.Bai, D.Yu, G.H.Lu, F.Liu, Q.Wang, H.Yilmaz: Applied Physics Letters, 2007, 91[6], 061926