Ultr shallow p$^{+}$-n junction with Co/Ti bilayer silicidde contact was formed by ion implantation of BF$_{2}$ [energy : (30, 50)keV, dose:($5{ imes}10^{14}$, $5{ imes}10^{15}$/$ extrm{cm}^2$] onto the n-well Si(100) region and by RTA-silicidation and post annealing of the evaporated Co(120.angs., 170.angs.)/Ti(40~50.angs.) double layer. The sheet resistance of the silicided p$^{+}$ region of the p$^{+}$-n junction formed by BF2 implantation with energy of 30keV and dose of $5{ imes}10^{15}$/$ extrm{cm}^2$ and Co/Ti thickness of $120{AA}$/(40~$50{AA}$) was about $8{Omega}$/${ox}$. The junction depth including silicide thickness of about $500{AA}$ was 0.14${mu}$. The fabricated p$^{+}$ -n ultra shallow junction depth including silicide thickness of about $500{AA}$ was 0.14${mu}$. The fabricated p$^{+}$-n ultra shallow junction with Co/Ti bilayer silicide contact did not show any agglomeration or variation of sheet resistance value after post annealing at $850^{circ}C$ for 30 minutes. The boron concentration at the epitaxial CoSi$_{2}$/Si interface of the fabricated junction was about 6*10$6{ imes}10^{19}$ / $ extrm{cm}^2$./TEX>.