Geometry based three dimensional reconstruction of a semiconductor specimen by solving an optimization problem, using at least two sem images acquired at different illumination angles

Abstract

There is provided a system and a method comprising obtaining a first (respectively second) image of an area of the semiconductor specimen acquired by an electron beam examination tool at a first (respectively second) illumination angle, determining a plurality of height values informative of a height profile of the specimen in the area, the determination comprising solving an optimization problem which comprises a plurality of functions, each function being representative of a difference between data informative of a grey level intensity at a first location in the first image and data informative of a grey level intensity at a second location in the second image, wherein, for each function, the second location is determined with respect to the first location, or conversely, when solving the optimization problem, wherein a distance between the first and the second locations depends on the height profile, and the first and second illumination angles.