Method of lithography or controlling lithography and method of lithography

Abstract

In a lithographic method, a measured overlay error map is determined using metrology of a first pattern formed on an integrated circuit (IC) chip by a lithography step performed using a first lithography method. A set of feedforward terms of a first type corresponding to the first lithography method are determined from the measured overlay error map, and are then transformed to a set of feedforward terms of a second type corresponding to a lithography method different from the first lithography method. Overlay compensation for a lithography step to be performed using the second lithography method is determined using at least the set of feedforward terms of the second type. The first lithography method may be optical lithography and the second lithography method may be nano imprint lithography, or vice versa.

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