Patent ID: 8638437
Filing Date: 2014-01-28
Classification: G01B,G01J,G01N

Abstract:
1. A method of aligning a sample comprising the steps of: a) providing a system comprising: such that in use said source of a beam of electromagnetic radiation provides a beam of electromagnetic radiation which has astigmatism introduced thereto by said means for introducing (CL) astigmatism, and is acted on by said imaging means (L 1 ) (L 2 ) to create an image of the source (LS) on said multi-element detector (MED) or single element position sensitive detector (SEPSD); b) defining a criteria for what constitutes sample alignment; said method further comprising the step of: c) while: until the location of, and geometric attributes of said monitored beam image pattern formed by said multi-element detector (MED) or single element position sensitive detector (SEPSD) meet said step b predetermined criteria for what constitutes sample alignment.