Hi So yesterday I was having some brainstorming with two guys from here in Portugal, who're going to join our maskless stepper aligner project. We were talking a bit about the substrate too. I think I'll use small glass squares, because for an initial stepper mechanism it's easier to just target single die exposure of like 1cm x 1cm or so, using the laser exposure technique used for photo epoxy 3D printers. I found some modules which might be suitable, so that we don't have to design it from scratch. Photoreactive dopant accepting polymer would really be a game changer tho. Otherwise we could try to "just" scale down a normal additive printer design to a micrometer scale... It will require multiple nozzles tho, because we need to feed more than just one material... p-doped, n-doped and isolator...
Cheers -lev
On Wednesday, March 9, 2022 5:07:33 AM WET Jacob Lifshay wrote:
On Tue, Mar 8, 2022, 14:25 David Lanzendörfer leviathan@libresilicon.com
wrote:
Hi Jacob Thanks for your contribution! So much appreciated! <3 Hmm... while the initial circuits may not be suitable for hardcore number crunching for hashing blocks, we might be able to use it for prototyping our layouts at home, which already would be awesome progress, especially if it could be done with chemicals which can be bought without ending up on a terror watch list. It would be interesting to see, whether we could build simple circuits like a 555 or maybe even a simple RISC-V MCU with it. Hagen shared another document here BTW: https://sci-hub.ee/https://doi.org/10.1002/adma.201302278
What's in your opinion the best way for patterning of structures using such polymer?
unfortunately, that's exactly the kind of question where I won't have a particularly useful answer, since that would require experience, and/or lots of research into the specifics of how such polymers behave, the different methods by which polymers can be patterned, etc. That's more the domain of materials engineering rather than chemistry... That said, I'd make a wild guess that electro-spinning may work well similar to how FDM 3D Printing works, except that the flow of fluid through the nozzle could be quickly changed by changing the electric field, rather than just adjusting a filament-feeder servo.
I was thinking, we could mix some photoreactive polymer like the
photoresist commonly used for photomasks in semiconductor manufacturing and then modify the chemical formulas in order to give them those dopant accepting properties.
that seems likely to break the photoreactive properties and/or the dopability. that said, it never hurt to try, though it may be time-consuming and expensive (specialty chemicals aren't generally cheap).
Then we could even use acryllic glas or so as a substrate (given the surface
is enough smooth)
hmm, i'd use something like glass, or some other ceramic material, since the solvents used can likely easily dissolve acrylic (iirc dcm, which is used in a lot of commercial acrylic solvents/bonders, is very chemically similar to chloroform, which i think is what they were using in that rsc.org paper). glass is easily cleaned, and is quite chemically similar to the SiO2 that they were using in the rsc.org paper, though you may have to watch out for contaminants contained in the glass, which depends on the exact composition of glass you have. I remember hearing about how sodium ions in common glasses can contaminate semiconductors, though that is Si-based semiconductors rather than organic semiconductors. fused silica may be a better option, since it is SiO2, though is more expensive.
Jacob