ELIMINATION OF THE TITANIUM NITRIDE FILM DEPOSITION IN TUNGSTEN PLUG TECHNOLOGY USING PE-CVD-Ti AND IN-SITU PLASMA NITRIDATION

摘要

An effective barrier layer to chemical attack of fluorine during chemical vapor deposition of tungsten from a tungsten fluoride source gas is fabricated by the present invention. A titanium nitride conformal barrier film (140) can be formed by in-situ nitridation of a thin titanium film (136). The substrate (28) is placed in a module (20) wherein the pressure is reduced and the temperature raised to 350 DEG C to about 700 DEG C. A titanium film (136) is then deposit by plasma-enhanced chemical vapor deposition of titanium tetrahalide and hydrogen. This is followed by formation of titanium nitride (140) on the titanium film (136) by subjecting the titanium film (136) to a nitrogen containing plasma (141) such as an ammonia, an N2 or an NH3/N2 based plasma (141). Tungsten (142) is then deposited on the film of titanium nitride (140) by plasma-enhanced chemical vapor deposition. All the titanium deposition and nitridation steps may be conducted in the same processing module (20) without removing the substrate (28) from the module (20) until the reaction steps are completed. The tungsten deposition step may be preformed in a separate processing module or in the module (20) used to deposit and process the titanium.