Patent ID: 6214732
Filing Date: 2001-04-10
Classification: B24B,H01L

Abstract:
A method for detecting endpoint in a chemical mechanical polishing operation, comprising the steps of:(a) polishing a metal-containing film using a chemical mechanical polishing operation including an acidic slurry;(b) withdrawing an effluent slurry stream from said polishing operation;(c) directing a sample of said stream into a sampling vessel;(d) providing a solid electrolyte coupled to a reference electrode within said sampling vessel and wherein said stream sample forms a liquid-phase working electrode contacting said solid electrolyte and thereby forming an electrochemical cell, said solid electrolyte selected to allow for chemical interaction between said reference electrode and said working electrode;(e) measuring an electric potential difference between said working electrode and said reference electrode; and(f) adjusting said polishing operation responsive to a change in said difference.