Design of combined microscopical and scatterometrical imaging device of surface inspection

Since the primary image in microscopic devices is nothing else than the scatter image of the aperture under investigation, an imaging scatterometer could be used as a microscope as well. It is self-evident to seek a combination: in both domains only the power distribution can be obtained with low effort, so a direct conversion into each other via Fourier transform is not the way to go. On the other hand, both domains have their advantages: while the original image shows the large structures, in other words the lower frequencies, the scatter image resolves the high spatial frequencies. The current paper deals with theoretical and practical aspects of basic design concepts. A corresponding paper is dedicated to concepts of the combined data analysis.