Calculating the surface topography of integrated circuit wafers from SEM images

The ability to make 3D measurements of surface topography is important to the control of quality in the fabrication of IC wafers. We describe a technique using shape from shading to produce a dense depth map from ICs imaged in the scanning electron microscope. The method minimizes error terms to ensure the resultant surface is everywhere continuous and accurately explains the observed image intensities. We describe how this method is extended when stereo images are available, and show results for synthetic and real images. © 1991.