Patent ID: 6292265
Filing Date: 2001-09-18
Classification: B24B,H01L

Abstract:
A method for optical control of the quality of a process of chemical mechanical planarization (CMP) performed by a polishing tool applied to an article by detecting whether there exists at least one of, erosion and dishing effects on the article caused by the CMP process, wherein the article has a patterned area which contains a plurality of stacks each formed by a plurality of different layers, the surface of the processed article having at least one pattern in the form of spaced-apart metal regions separated by non-metal regions, the method comprising the steps of:(a) selecting at least one predetermined measurement site within the patterned area of the article;(b) illuminating said at least one predetermined measurement site in the article with incident radiation of a preset substantially wide wavelength range;(c) detecting spectral characteristics of light components reflected from the at least one illuminated site of the article, and generating data representative thereof; and(d) analyzing said data for determining a thickness of at least one layer of the article within said at least one illuminated site to determine whether the thickness value is indicative of the existence of at least one of erosion and dishing effects being thereby indicative of the quality of the CMP process applied to the article, the analysis of said data utilizing a proper optical model based on at least some features of the article and operable to determine data representative of photometric intensities of light components of different wavelengths reflected from the article.