Focus blur measurement and control method

Abstract

A method for optimizing imaging and process parameter settings in a lithographic pattern imaging and processing system is disclosed. The method includes correlating the dimensions of a first set of at least one control pattern printed in a lithographic resist layer, measured at three or more locations on or within the pattern which correspond to differing dose, defocus and blur sensitivity. The method then includes measuring the dimensions on subsequent sets of control patterns, printed in a lithographic resist layer, at three or more locations on or within each pattern, of which a minimum of three locations match those measured in the first set, and determining the effective dose, defocus and blur values associated with forming the subsequent sets of control patterns by comparing the dimensions at the matching locations with the correlated dependencies. A method for determining blur, focus and exposure dose error in lithographic imaging is also disclosed.