Inventors:
Jiri Pecen - Palo Alto CA
Saket Chadda - Colorado Spring CO
Rahul Jairath - San Jose CA
Wilbur C. Krusell - Palo Alto CA
Assignee:
Lam Research Corporation - Fremont CA
International Classification:
G01B 1106
US Classification:
356630, 451 6, 451303, 451 41, 438690
Abstract:
An apparatus and method for in-situ monitoring of thickness during chemical-mechanical polishing (CMP) of a substrate using a polishing tool and a film thickness monitor. The tool has an opening placed in it. The opening contains a monitoring window secured in it to create a monitoring channel. A film thickness monitor (comprising an ellipsometer, a beam profile reflectometer, or a stress pulse analyzer) views the substrate through the monitoring channel to provide an indication of the thickness of a film carried by the substrate. This information can be used to determine the end point of the CMP process, determine removal rate at any given circumference of a substrate, determine average removal rate across a substrate surface, determine removal rate variation across a substrate surface, and optimize removal rate and uniformity.