Exposure system, test mask for monitoring polarization, and method for monitoring polarization

摘要

An exposure system includes an exposure tool configured to project grating patterns oriented in different directions onto test areas by a linearly polarized light, respectively, each of the grating patterns having a space width preventing higher order diffracted lights from an image formation, a data collector configured to collect sets of test optical intensity data on the test areas, and a polarization direction monitor configured to monitor a polarization direction of the linearly polarized light by comparing the sets of the test optical intensity data.