Determining calibration parameters for a lithographic process

摘要

A technique for determining a set of calibration parameters for use in a model of a photo-lithographic process is described. In this calibration technique, images of a test pattern that was produced using the photo-lithographic process are used to determine corresponding sets of calibration parameters. These images are associated with at least three different focal planes in an optical system, such as a photo-lithographic system that implements the photo-lithographic process. Moreover, an interpolation function is determined using the sets of calibration parameters. This interpolation function can be used to determine calibration parameters at an arbitrary focal plane in the photo-lithographic system for use in simulations of the photolithographic process, where the set of calibration parameters are used in a set of transmission cross coefficients in the model of the photo-lithographic process.

主权项

1. A computer-implemented method for determining a set of calibration parameters for use in a model of a lithographic process, comprising:
obtaining a plurality of sets of calibration parameters associated with a plurality of images of a test pattern produced using a lithographic system that implements the lithographic process, each of the plurality of images of the test pattern corresponding to a distinct focal plane in the lithographic system; and determining an interpolation function based on the plurality of sets of calibration parameters, the interpolation function providing a set of calibration parameters corresponding to an arbitrary focal plane in the lithographic system that implements the lithographic process, and the set of calibration parameters used in a set of transmission cross coefficients in the model of the lithographic process.