摘要 |
In the forming process of buried wirings by filling wiring trenches formed in an insulator with a conductive film mainly made of Cu, the buried wirings are formed to have a uniform-height regardless of the width and density of the wiring trenches. When polishing a barrier conductor film comprised of a Ta film in the CMP process for forming the buried wirings, the polishing agent which can control the removal rate of the underlying insulator of a silicon oxide film relative to the barrier conductor film to almost one twentieth or less is used as the slurry, and the pad made of polyurethane with a hardness of 75 degrees or more measured by the Type E durometer in conformity with the JIS K6253, which is comprised of the foam including non-uniform pores with a diameter of about 150 mum or larger and a density of about 0.4-0.6 g/cm<3>, is used as the polishing pad.
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