METHODS AND SYSTEMS FOR DETERMINING RETICLE DEFORMATIONS

摘要

The present disclosure relates to techniques for improving the accuracy of the determination of the deformation of a reticle. Process corrections may be determined and applied in dependence on the determined deformation to reduce reticle induced errors in a lithographic process.A lithographic apparatus is a machine constructed to apply a desired pattern onto a substrate.A lithographic apparatus can be used, for example, in the manufacture of integrated circuits (ICs). A lithographic apparatus may, for example, project a pattern of a patterning device (e.g., a mask, a reticle) onto a layer of radiation-sensitive material (resist) provided on a substrate.To project a pattern on a substrate a lithographic apparatus may use electromagnetic radiation.The wavelength of this radiation determines the minimum size of features which can be formed on the substrate. A lithographic apparatus, which uses extreme ultraviolet (EUV) radiation, having a wavelength within the range 4-20 nm. for example 6.7 nm or 13.5 nm, may be used to form smaller features on a substrate than a lithographic apparatus which uses, for example, deep ultraviolet (DUV) radiation with a wavelength of 157 nm or 193 nm or 248 nm.