Published online by Cambridge University Press: 22 February 2011
The redistribution of boron implanted into TaSi2/poly-Si gates after high temperature anneals has been studied as a function of the implantation dose and energy as well as implantation scheme, i.e. boron implantation either into the silicide or into the poly-Si prior to TaSi2 deposition. SIMS measurements indicate that boron can easily diffuse from TaSi2 into poly-Si and vice versa at 900 °C. Independent of the implantation scheme, the boron concentration within poly-Si was found to saturate at approximately 1 × 1019 at/cm3 for boron doses greater than 5 × 1014 at/cm2. The excess of boron always accumulates within the silicide. The observed boron redistribution behavior within polycrystalline TaSi2/poly-Si layers is discussed in terms of combined lattice and grain boundary diffusion as well as grain boundary segregation.