SYSTEM AND METHOD FOR ALIGNMENT IN SEMICONDUCTOR DEVICE FABRICATION

摘要

A method of determining overlay error in semiconductor device fabrication includes receiving an image of an overlay mark formed on a substrate. The received image is separated into a first image and a second image, where the first image includes representations of features formed on a first layer of the substrate and the second image includes representations of the features formed on a second layer of the substrate. A quality indicator is determined for the first image and a quality indicator is determined for the second image. In an embodiment, the quality indicators include asymmetry indexes