This invention relates to a process for forming a metal interconnect comprising the steps of forming a concave in an insulating film formed on a substrate, forming a barrier metal film on the insulating film, forming an interconnect metal film over the whole surface such that the concave is filled with the metal and then polishing the surface of the substrate by chemical mechanical polishing, characterized in that the polishing step comprises a first polishing step of polishing the surface such that the interconnect metal film partially remains on the surface other than the concave and a second polishing step of polishing the surface using a polishing slurry controlling a polishing-rate ratio of the interconnect metal to the barrier metal to 1 to 3 both inclusive, until the surface of the insulating film other than the concave is substantially completely exposed. According to this invention, dishing and erosion can be prevented and a reliable damascene interconnect with a small dispersion of an interconnect resistance can be formed.
本发明涉及一种形成
金属互连器件的工艺,包括以下步骤:在基板上形成的绝缘膜上形成凹面,在绝缘膜上形成阻挡
金属膜,在整个表面上形成互连
金属膜,使凹面充满
金属,然后通过
化学机械抛光对基板表面进行抛光、其特征在于,抛光步骤包括:第一抛光步骤,抛光表面,使互连
金属膜部分留在凹面以外的表面上;第二抛光步骤,使用抛光浆料抛光表面,控制互连
金属与阻挡
金属的抛光速率比为 1 至 3(包括 1 和 3),直到凹面以外的绝缘膜表面基本上完全暴露出来。根据本发明,可以防止分层和侵蚀,并形成可靠的大马士革互连,互连电阻的分散程度很小。