| 摘要 |
PROBLEM TO BE SOLVED: To prevent the occurrence of seams along the center lines of plugs at the removal of a tungsten film by specifying the film forming condition at the formation the tungsten film over the whole surface of a substrate by the CVD method. SOLUTION: After a base oxide film 1 is formed on a semiconductor substrate, an Al wiring 2 is formed on the film 1 and an interlayer insulating film 3 is formed over the whole surface of the substrate and planarized. Then through-holes 4 are formed to the Al wiring 2 through the insulating film 3, and a barrier layer is formed by forming a TiN film over the whole surface of the substrate including the internal surface of the holes 4. Successively, the holes 4 are filled by thinly growing tungsten crystallites on the internal surfaces of the holes 4 and forming a CVD tungsten film over the whole surface of the substrate. At the formation the tungsten film, a temperature T of the substrate and a pressure P in the film forming chamber are respectively adjusted to T>475 deg.C and 90<P<=150 Torr, so that the film may become a high-density tungsten film 5. Then the tungsten film 5 is removed from the surface of the substrate by the CMP method, and an Al wiring 6 is laid on obtained tungsten plugs 9.
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