Patent ID: 6323938
Filing Date: 2001-11-27
Classification: G03F

Abstract:
A method for characterizing performance of a photolithography system, comprising the acts of:exposing at least one image of a critical dimension mark on a photosensitive material on a substrate using the photolithography system, whereby the critical dimension mark is tailored for line width or critical dimension measurement of the photolithography system;exposing at least one sigma sensitive parameter image on the photosensitive material using the photolithography system, whereby the sigma sensitive parameter image is sensitive to partial coherence variation or sigma variations of the photolithography system, and wherein the acts of exposing use the same exposure conditions, wherein each of a plurality of locations for the sigma sensitive parameter image has a corresponding location for the image of the critical dimension mark;selecting a reference location of the exposed critical dimension mark image and the sigma sensitive image;for each of the plurality of locations and the reference location for the sigma sensitive parameter exposed image, measuring a value;for each of the plurality of corresponding locations and the reference location for the exposed image of the critical dimension mark, measuring a value;determining for each of the plurality of locations for the sigma sensitive parameter image, a difference between the measured value and the measured value at the reference location;determining for each of the plurality of locations for the image of the critical dimension mark, a difference between the measured value and the measured value at the reference location, whereby a relationship at each location between the difference for the sigma sensitive parameter image and the corresponding difference value for the image of the critical dimension mark characterizes the photolithography system.