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

A scanning electron microscope configured to evaluate one or more properties of a sample, the sample comprising a plurality of repeating features, the scanning electron microscope comprising:

• a scanning arrangement configured to scan a site on the sample by irradiating it with a plurality of source particles and detecting resulting signals produced by the sample;
• and
• a controller configured to direct operation of the scanning electron microscope, and to evaluate one or more predetermined properties at the site at least partially based on measurements of the detected signals;
• the controller being further configured to:
• direct the scanning arrangement to scan equivalent sites of interest on each of the plurality of repeating features for a scan-duration, each of the scan-durations being substantially less than a predetermined acquisition-duration and the sum of the scan-durations being at least as long as the acquisition-duration, wherein evaluation of the one or more predetermined properties requires scanning the site of interest for the acquisition-duration;
• aggregate measurements of the detected signals produced by each of the equivalent sites of interest;
• and
• evaluate the one or more predetermined properties of the sites of interest on the plurality of repeating features based at least partially on the aggregated measurements.