Effect of Various W Film and Barrier Material on the Corrosion during W CMP

The Tungsten (W) has been widely used as contact or wire material in the integrated circuit (IC) fabrication because of its low resistance and superior gap-fill property. The damascene process based on chemical mechanical polishing (CMP), which is used to remove the protruding W, make it possible to use W as interconnection material. During the W CMP, the W loss, well known as dishing and erosion, leads to resistance increase. Recently, undesirable metal loss, such as corrosion, was observed at the interface between the W and barrier metal. In this paper, the effect of various W film and barrier material on W CMP performance was investigated through surface analysis and electrochemical analysis.