Scanning electron microscope and methods for evaluating properties of a sample therewith

Abstract

A scanning electron microscope (SEM) is provided, configured to evaluate one or more properties of a sample comprising a plurality of repeating features. The SEM comprises a scanning arrangement to scan a site on the sample by irradiating it with source particles and detecting resulting signals, and a controller to operate the SEM and evaluate properties at the site based on the signals. The scanning arrangement scans equivalent sites of interest on the features for a scan-duration which is less than an acquisition-duration necessary for evaluation of a property of interest. The sum of the scan-durations is no less than the acquisition-duration. The controller aggregates measurements of the detected signals produced by each of the equivalent sites of interest, and evaluates one or more predetermined properties of the sites of interest on the plurality of repeating features based at least partially on the aggregated measurements.

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