Method and apparatus for measuring three-dimensional shape of specimen by using SEM

摘要

The present invention relates to a method and apparatus for measuring a three-dimensional profile using a SEM, capable of accurately measuring the three-dimensional profile of even a flat surface or a nearly vertical surface based on the inclination angle dependence of the amount of secondary electron image signal detected by the SEM. Specifically, a tilt image obtaining unit obtains a tilt image (a tilt secondary electron image) I( 2 ) of flat regions a and c 1 on a pattern to be measured by using an electron beam incident on the pattern from an observation direction phi( 2 ). Then, profile measuring units presume the slope (or surface inclination angle) at each point on the pattern based on the obtained tilt image and integrate successively each presumed slope value (or surface inclination angle value) to measure three-dimensional profiles S 2 a and S 2 c. This arrangement allows a three-dimensional profile to be accurately measured.