Method of forming contact plugs in semiconductor device having different sized contact holes

摘要

The present invention discloses a forming method for metal wiring in a semiconductor device with different sized contact holes. The metal wiring in a semiconductor device according to the present invention is formed by the following processes. First, a semiconductor substrate on which an insulation film having a plurality of different sized contact holes is formed is provided. A barrier metal layer is then formed on the substrate and a first tungsten film is formed on entire surface of the barrier metal layer thick enough to fill relatively smaller contact hole among the different sized contact holes. Next, the first tungsten film and the barrier metal layer are removed to expose the top surface of the insulation film. A second tungsten film is formed selectively on the contact holes thick enough to completely fill relatively larger contact hole among the different sized contact holes and the surface of the substrate is then planarized.