Reducing the impact of charged particle beams in critical dimension analysis

摘要

Measuring a feature on a wafer, the feature including at least two edges. Scanning the wafer with an electron beam over the length of a first scan interval that includes at least a portion of a first edge of the feature. Preventing the electron beam from illuminating the wafer while moving the scan position of the electron beam across a portion of the wafer to a second scan interval that includes at least a portion of a second edge of the feature. Scanning the wafer with an electron beam over the length of the second scan interval. Determining a distance between the first and second edges of the feature.