Influence of processing parameters on selectivity in a CVD-process of copper using Cu/sup +1/(hfac)(TMVS)

Copper is a promising metallization material for ULSI, because it has a lower resistivity and a higher EM resistance than aluminum alloys. Shrinking geometries and multilevel metallization cause the problem of filling vias and contact holes with high aspect ratio. CVD processes have the potential for good step coverage even for high aspect ratios. Unless there are very promising results in dry etching of copper no standardized process is available yet. Patterning of copper is done in most cases by chemical mechanical polishing (CMP) in a damascene process, but some difficulties still remain using this process. Selective CVD could be a way to overcome these problems. The paper presents the results of investigating factors which affect the selectivity of a Cu MOCVD process.