| 摘要 |
PURPOSE: A method for forming a tungsten bit line of a semiconductor device is provided to prevent a deterioration in characteristics of the bit line during a succeeding heat process for forming a capacitor. CONSTITUTION: After an interlayer dielectric(12) is formed on a semiconductor substrate(11), a bit line contact(13) through which a junction region in the substrate(11) is exposed is formed in the interlayer dielectric(12). Thereafter, an alloy layer(14A) of titanium and tungsten is formed both in the bit line contact(13) and on the interlayer dielectric(12). The alloy layer(14A) may include titanium of 5 to 15 weight percents. Next, by a rapid thermal anneal process under nitrogen gas, the interface between the junction region in the substrate(11) and the alloy layer(14A) is turned into a titanium/tungsten silicide layer(15) having a hexagonal structure, and further, the top surface of the alloy layer(14A) is turned into a titanium nitride layer(14B). Here, the titanium/tungsten silicide layer(15) and the titanium nitride layer(14B) constitute a diffusion barrier(14). A tungsten bit line(16) is then formed on the diffusion barrier(14).
|
