Lithographic system, lithographic method and device manufacturing method

摘要

A lithographic system includes a lithographic apparatus and a scatterometer. In an embodiment, the lithographic apparatus includes an illumination optical system arranged to illuminate a pattern and a projection optical system arranged to project an image of the pattern on to a substrate. In an embodiment, the scatterometer includes a measurement system arranged to direct a beam of radiation onto a target pattern on said substrate and to obtain an image of a pupil plane representative of radiation scattered from the target pattern. A computational arrangement represents the pupil plane by moment functions calculated from a pair of orthogonal basis function and correlates the moment function to lithographic feature parameters to build a lithographic system identification. A control arrangement uses the system identification to control subsequent lithographic processes performed by the lithographic apparatus.

主权项

1. A method of using a lithography system, the method comprising:
projecting, using a projection system, a beam of radiation onto a target on a substrate; obtaining pupil plane images from the target on the substrate for a plurality of parameters of a lithographic apparatus, each of the pupil plane images corresponding to a respective parameter of the plurality of parameters of the lithographic apparatus, each parameter of the plurality of parameters of the lithographic apparatus being different from other parameters of the plurality of parameters of the lithographic apparatus; determining a magnitude of vibration in the lithographic apparatus based on at least two of the pupil plane images obtained at different times; calculating moment functions based on intensities of the pupil plane images, each of the moment functions being a representative of a corresponding one of the pupil plane images; determining a lithographic system identification based on correlations between the moment functions and the plurality of parameters of the lithographic apparatus or features of the target; and adjusting, using a lithography controller, one or more parameters from among the plurality of parameters of the lithographic apparatus based on the lithographic system identification to control a lithographic process.