Scan linearity: a hidden factor in SEM magnification calibration

Abstract

Scan linearity of a review (cross-section) Scanning Electron Microscope (SEM) has been studied using Nanometrology’s proprietary software and reference samples. Nonlinearity across the field of view was measured at greater than 6.5% before and under 1% after correction by the SEM company’s engineer. The scan non-linearity was measured with precision better than 0.2% across the field of view. This is in spite of the nonuniformity of the reference sample which was measured at greater than 2.5%. The precision of the non-uniformity measurement of the reference sample was better than 0.1%.