Patent ID: 7351968
Filing Date: 2008-04-01
Classification: G01N,H01J

Abstract:
1. A process of detecting defects on a substrate, the process comprising: directing a first incident beam to be incident on a first multi-pixel imaging region; simultaneously detecting electrons emitted from a plurality of pixels within the first multi-pixel imaging region; generating a first image data set comprising signal values representing image content of the plurality of pixels within the first multi-pixel imaging region; directing a second incident beam to be incident on a second multi-pixel imaging region for comparison with the first multi-pixel imaging region; simultaneously detecting electrons emitted from a plurality of pixels within the second imaging region; generating a second image data set comprising signal values representing image content of the plurality of pixels within the second multi-pixel imaging region; storing the first and second image data sets in memory; determining a misalignment between the first and second image data sets with a resolution of a fraction of one pixel; aligning the image data sets by adjusting one of the image data sets to correct the misalignment; and comparing the aligned first and second image data sets to detect differences therebetween.