Study on the effect of incorporating nitrogen ions on titanium disilicide thin film formation for ULSI applications

Abstract

The impact of N+ ions on the formation of TiSi2 thin film is studied. The substrates used were 200 mm diameter p-type (100)-oriented silicon wafers. Nitrogen were introduced through the ion implantation technique. All samples were processed until formation of the first metal layer to facilitate electrical testing of narrow poly-Si and active diffusion sheet resistance. The thickness of the film was determined by scanning electron microscopy. Cross sectional transmission electron microscopy was carried out to characterize their defects. Partial activation of N+ ions as n-type dopant was observed, which caused a negative-shifting in threshold voltage and a junction-deepening effect.