Perfecting Large Area, High Resolution SEM Imaging with 3D-Stitching
For large area, high resolution SEM imaging applications in semiconductor reverse engineering, materials science, and life sciences (e.g. connectomics), traditional SEM instruments are inherently limited by small, uncalibrated fields of view (FOVs) and imprecise sample positioning. These limitations affect image capture throughput, requiring more stage drive time and larger image overlaps. Furthermore, these limitations introduce stitching errors in 3 dimensions of the image data, X, Y, and Z. Throughput and stitching errors are cited challenges in large area, high resolution SEM . Software corrections to the stitching errors have so far proven insufficient because it cannot tenably correct stitching errors in large image datasets and it can even introduce additional errors into the image data via the scaling, rotation, and twisting of the images.
The CHIPSCANNER addresses these challenges by combining the resolution and flexibility of the SEM instrument with the accuracy (of the order 10 nm), stability, and automation of the electron beam lithography (EBL) instrument. With its unique combination of high resolution SEM imaging (up to 50,000 pixels x 50,000 pixels for each image), myriad electron detectors, laser interferometer stage positioning, and FOV mapping, the CHIPSCANNER produces the most accurate large area, high resolution images directly acquired by an SEM instrument. Since the absolute position of each pixel is known ultimately to the accuracy afforded by the laser interferometer stage, these images can be stacked (3D-stitched) with the highest possible accuracy.
References:  A A Wanner et al, Journal of Microscopy 259 (2015), pp. 137-142.