一种改善双大马士革刻蚀缺陷的工艺方法分析

Study and Implementation of Low Temperature injection Substitution in 40nm Process

阐述工艺线宽的不断微缩以及铜互连层数的不断增加,对后段刻蚀工艺中的缺陷提出更高要求。缺陷物在腔体内形成之后容易在刻蚀当中掉落在晶圆表面,从而形成阻挡刻蚀的缺陷。除减少缺陷物的形成之外,避免缺陷物在刻蚀当中掉落也是一种有效的缺陷改善手段,而这一目的可以通过研究不同刻蚀步骤之间的差异,优化不同步骤之间的衔接方式来达成。探讨以双大马士革刻蚀工艺中的阻挡刻蚀缺陷为研究对象,确定了其掉落在晶圆表面的具体刻蚀步骤,并以一种新的步骤衔接方式,以最小的工艺实现缺陷的明显改善。

This paper describes that the continued scaling in logic technology and the increasing number of copper interconnection layers,have posed great challenges such as stricter requirements on defects in BEOL.Defects formed in the chamber can easily fall on the wafer during etch process,thereby forming defects that block etch.In addition to eliminating the formation of defects,preventing defects from falling is also an effective defect improvement means,which can be achieved by studying the differences and optimizing the connection between etching steps.This work takes the block etch defect in the dual damascene etch process as the research object,finding the specific etching steps where defects are fallen,and achieves significant improvements in defects with a new step connection method.