Interactions between implantation defects and phosphorus diffusion in crystalline silicon were studied. Defect engineering permitted ultra-shallow n+/p junction formation using phosphorus, carbon and germanium co-implants, and spike annealing. Experimental data suggested that the positioning of a pre-amorphized layer using germanium implantation played an important role in phosphorus diffusion. It was found that extending the overlap of germanium pre-amorphization and carbon profiles resulted in a greater reduction of phosphorus transient-enhanced diffusion, by trapping more excess interstitials. This conclusion was consistent with the end-of-range defects calculated by Monte Carlo simulation and annealed carbon profiles.

Effects of Germanium and Carbon Coimplants on Phosphorus Diffusion in Silicon. K.C.Ku, C.F.Nieh, J.Gong, L.P.Huang, Y.M.Sheu, C.C.Wang, C.H.Chen, H.Chang, L.T.Wang, T.L.Lee, S.C.Chen, M.S.Liang: Applied Physics Letters, 2006, 89[11], 112104