Patent Document ID: 20120191236
Application ID: 13012179
Patent Flag: 0

Claim One:
1. A method for dynamically controlling variation during an exposure step of a patterning process using an exposure tool comprising: measuring a set of one or more pattern attributes at a set of discrete locations on a substrate; selecting one or more basis functions representing one or more variations in the set of one or more pattern attributes over the set of discrete locations; constructing an orthogonal set of functions from the set of one or more basis functions; fitting the orthogonal set of functions to the measured set of one or more pattern attributes at the set of discrete locations; determining, as a result of said fitting, a set of coefficients of the orthogonal set of functions; and minimizing a variation in the one or more pattern attributes by adjusting the exposure tool or the patterning process according to one or more said determined set of coefficients.