Synopsys, Inc.

Xin Zhou

Robert E Gleason

Yaogang Lian

Jun Peng

Guoqiang Bai

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.

Determining calibration parameters for a lithographic process

A technique for providing information about defects in a mask pattern is described. In this technique, defects in the mask pattern may be determined based on differences between a calculated pattern produced at an image plane in the photolithographic process, when the mask pattern, illuminated by an associated source pattern, is at an object plane in the photolithographic process, and a target pattern that excludes the defects. Then the defect information may be provided to the user, such as a spatial map of the determined defects, where the spatial map is associated with at least the portion of the mask pattern.

Spatial map of mask-pattern defects

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 photo-lithographic process, where the set of calibration parameters are used in a set of transmission cross coefficients in the model of the photo-lithographic process.

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Saratoga, CA, United States of America

Xin Zhou