The effects of Ti film thickness and rapid thermal annealing (RTA) ambient on the properties of narrow TiSi2 lines were studied. Decreasing the Ti film thickness improves the critical line width of silicidation. Excessive nitridation suppresses the silicidation at Ti film thickness thinner than 30 nm in atmosphere N-2 RTA. Using a low-pressure N-2 RTA process (30 mTorr), a 0.10 mu m line width with low resistivity was accomplished at the Ti film thickness of 20 nm without lateral overgrowth.