Optical end point detection methods in semiconductor planarizing polishing processes

摘要

A semiconductor processing method of detecting polishing end point from a polishing planarization process includes: a) impinging laser light onto an area of an outermost surface of a semiconductor substrate at an angle of incidence of at least 70 DEG from a line normal relative to the substrate (at least 60 DEG for s-polarized light), the impinged laser light predominantly reflecting off the area as opposed to transmitting therethrough; b) measuring intensity of the light reflected off the area; c) polishing the substrate outermost surface; d) repeating step "a" then step "b"; and e) comparing a prior measured intensity of reflected light with a later measured intensity of reflected light to determine a change in degree of planarity of the semiconductor substrate outermost surface as a result of polishing.