Method of calibrating a lithographic apparatus, device manufacturing method and associated data processing apparatus and computer program product

Abstract

A lithographic apparatus is calibrated by reference to a primary reference substrate. Using an apparatus which need not be the same as the one being calibrated, there is obtained an apparatus-specific fingerprint of the primary reference substrate. Using the same set-up there is then obtained an apparatus-specific fingerprint of a secondary reference substrate. The apparatus-specific fingerprint of the primary reference substrate is subtracted from the apparatus-specific fingerprint of the secondary reference substrate to obtain and store an apparatus-independent fingerprint of the secondary reference substrate. The secondary reference substrate and stored apparatus-independent fingerprint are subsequently used together in place of the primary reference substrate as a reference for the calibration of the lithographic apparatus to be calibrated. Initial set-up for a cluster of lithographic tools can be performed with less use of the costly primary reference substrate, and with less interruption to normal production. The initial set-up can be integrated with on-going monitoring and re-calibration of the apparatuses.