I have no practical use for something like this but I have always wanted to build one. Archive: https://archive.today/zPvAK From the post: >>If you want to build semiconductors at home, it seems like the best place to start might be to find a used scanning electron microscope on eBay. At least that’s how [Peter Bosch] kicked off his electron beam lithography project, and we have to say the results are pretty impressive.