| It's totally doable! Although it does take some non-household equipment and chemicals. But much of the equipment you need can be purchased off ebay for relatively cheap. It's actually a hobby project I'm working on right now, to create some large transistors and simple circuits. My goal is 10um process (aka 1970's technology), but I'd be pretty happy with something a few orders of magnitude higher. Jeri Ellsworth is the first that I'm aware of having created some large transistors (NMOS process) in her garage and documented the process: - https://hackaday.com/2010/05/13/transistor-fabrication-so-si... - http://4hv.org/e107_plugins/forum/forum_viewtopic.php?85399.... And Sam Zeloof very recently did similar: - https://hackaday.com/2017/02/25/the-fab-lab-next-door-diy-se... - Lots of other cool stuff on his blog too, like a SEM he restored in his garage, sputtering experiments, etc: http://sam.zeloof.xyz/ As for me, I'm tackling the maskless lithography step first and repurposing a pico projector with modified optics, laser and translation XY stage. More details being blogged actively here: https://hackaday.io/project/25260-makerfoundry > Would the physics work at that large scale? It could be a cool way to demonstrate the concepts. Transistors definitely work at the macro scale (see Jeri and Sam's transistors), but they do have some funky properties. Their switching speed is slow, and due to impurities in the process tend to be unstable or have weird thresholds. Edit: Since folks keep mentioning toxic chemicals, thought I'd list some that are involved. They are unpleasant, but not terribly awful in the grand scheme of chemicals. Mostly just strong acids and bases, but not a whole slew of neurotoxins or anything: - Piranha solution (sulfuric acid + hydrogen peroxide) - RCA clean 1 (ammonia hydroxide + hydrogen peroxide) - RCA clean 2 (hydrochloric acid + hydrogen peroxide) - Oxide strip (hydrofluoric acid) - Various photoresist developers (potassium hydroxide, sodium hydroxide, tetramethylammonium hydroxide) - Wet etchants (similar to developers, KOH, NaOH, etc) So yeah, some strong acids and bases there, but nothing that isn't handled in undergrad ochem lab courses. The only nasty one in there really is HF, simply because of it's propensity to dissolve bone and not feel the burn until it's seeped in. But Jeri Ellsworth has shown that it's doable to use the dilute HF cleaner you can find in the super market (Rust Remover) which is ~3% iirc, and much less toxic. When I worked in a wet bio lab, we handled nastier stuff routinely (acrylamide, ethidium bromide, etc) with a lot less caution (gloves, labcoat, goggles, common sense, you're good). |