System, method, and medium for an endpoint detection scheme for copper low-dielectric damascene structures for improved dielectric and copper loss

摘要

A system, method and medium of detecting a transition interface between a first dielectric material and an adjacent second dielectric material in a semiconductor wafer during a chemical-mechanical polishing process includes impinging an incident light of a predetermined wavelength on the semiconductor wafer at a first time, detecting at least one first intensity of at least one first reflected light, impinging the incident light of the predetermined wavelength on the semiconductor wafer at a second time, detecting at least one second intensity of at least one second reflected light, and determining a difference between the at least one first intensity and the at least one second intensity. If the difference between the at least one first intensity and the at least one second intensity is above a predetermined threshold, the chemical-mechanical polishing process is terminated.