Patent ID: 8589831

Claim:
A method of accurately determining effects of one or more processing variations caused by a use of multiple masks in a multi-patterning lithography process, comprising: operating a computer system to define a plurality of skew sensitive indices corresponding to a variation in an operating parameter due to one or more processing variations caused by a multiple mask exposure process; operating the computer system to assign one of the plurality of skew sensitive indices to one or more sections of a route on a multi-patterning layer based upon a section's sensitivity to the one or more processing variations; generating one or more skew variations by operating the computer system to respectively multiplying skew sensitive indices assigned to the one or more sections with runlengths of the one or more sections; and determining a skew variation sum, indicative of the effects of the one or more processing variations, by operating the computer system to sum the one or more skew variations.