alt Hacker NewsIn general, hobby photo-lithography projects already use DMD/DLP projectors, and some inexpensive optics.
Huygens Optics:
https://www.youtube.com/watch?v=_w0Z2Y5vaAQ
Sam Zeloof:
https://www.youtube.com/watch?v=Nxz_ENnmgtI
In general, getting vanity silicon made is usually much less expensive than trying to bootstrap a fab line. =3
I think half the fun for people that do things like this is figuring out how to out innovate a multi-billion dollar company so that they can make something 1/4th as good but at 1/10000th the price. I bet there are some -really- innovative people out there that would figure alternatives to a lot of the expensive parts of the process and figure out how to be able to produce 2000's level chips at home. I'm not one of them though :)