Using an electron beam to image the tiniest of defects and patterns on microchips, the scanning electron microscope (SEM) has long been a mainstay of the semiconductor industry. But as the industry continues to miniaturize chip components—essential for computers, implantable drug dispensers, cellphones, and other devices—the demand for ever-more detailed information from SEM images has grown.

Although the exquisite, atomic-scale resolution of an SEM leaves little room for improvement, researchers at the National Institute of Standards and Technology (NIST), funded by the CHIPS metrology program, have begun a multiyear study to reduce uncertainties in the measurements inferred from SEM images. To do so, NIST physicist John Villarrubia and his colleagues are conducting a series of experiments in which electrons scatter off different materials. By comparing the results of the scattering experiments to theory, the team hopes to establish a more precise connection between SEM images and the features of the object under study.

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