Reference thickness endpoint techniques for polishing operations

摘要

A method and system for determining endpoint in a chemical mechanical polishing operation by measuring the amount of linear displacement of a member such as an assembly which secures the substrate being polished and urges the surface being polished towards the rotating polishing pad. The thickness of material being removed corresponds to the amount of linear displacement, and endpoint is achieved and therefore detected when a desired material thickness has been removed. The linear displacement can be measured using various techniques such as by using a dial gauge, laser or profilometer.