Well, this chap managed to make his own chips at home: http://sam.zeloof.xyz/category/semiconductor/

Plus an electron microscope!

Sam is super impressive, but to be fair he bought premade wafers and bought a used SEM.

Jeri Ellsworth has gone "deeper" into the process and made a few transistors, although at a much larger scale:

https://www.youtube.com/watch?v=w_znRopGtbE

https://www.youtube.com/watch?v=-Qph8BNrnLY

To me this is far more impressive than any of the other stuff posted here. It's actually doing it rather than talking about it or faking the first 99.9% of it.

Did he do his own etching? I'd say buying blank wafers would be a perfectly reasonable place to start, but if you're buying printed wafers, then you might as well buy the whole chip.

Yeah, I don't think people will be pulling pure silicon crystals at home any time soon.

That’s actually quite doable in a garage, assuming you are satisfied with, say, two inch wafers. (Currently, they are approaching 18 inches!)

It’s much easier to produce silicon ingots than to do wafer fab, because of the currently tiny line widths.

But, it would make more sense to simply buy wafers (or epitaxial wafers).

If they do, I imagine they’d leave it at that instead of going on to make a chip.

I believe he bought them with the gates etched & fets doped, and did his own metal. Something like that.

He used wafers with premade structures on it.

No, Sam Zeloof started from blank silicon wafers and did four layers of photolithography to produce PMOS gates. He used boric acid for the boron diffusion. He sputtered an aluminum layer on top for the metal and etched it with phosphoric acid.

http://sam.zeloof.xyz/first-ic/

So he "only" did metal deposition to make the interconnects? I haven't read the story, but I was thinking that there's no way you would handle some of the toxic chemicals used for doping.

They are not really that toxic. You do have to have a chemistry background and use a fume hood and a process sink with acid neutralization capability, like you find in many chem labs.

Good dopant choices would be phosphorus oxychloride and oxidized boron nitride wafers.

As I recollect, he started with silicon wafers with an epitaxy layer. He then did the usual oxidations, diffusions, and metallization, along with all the photolithographic steps. No small feat!

Ok. I was never a process guy, but worked with some back in the day and they told me that one of their phosphorus sources was phosgene gas.

Silane, phosphene, and diborane gases are used to form epitaxial layers on silicon wafers. Those are truly dangerous gases. However, a simple wafer process using the reagents I mentioned can produce very credible ICs, if one buys the epi wafers.

If you knew enough VHDL you can make your own digital chips including CPUs using off the shelf FPGAs...

https://blog.classycode.com/implementing-a-cpu-in-vhdl-part-...

Yeah, certainly true, but FPGAs are beholden to the same supply chain. This doesn’t fix the issue at all.

Helps a lot though, it's much easier to be a consumer of a commodity (the FPGA) than to make the supply chain produce your bespoke product.

how steep is the learning curve for VHDL?

I made a simplified MIPS (no FPU, 4-stages pipeline with a basic interrupt controller and nothing out of order or the like) in VHDL for a uni course. We had some simpler exercises before that (e.g., PS2 keyboard controller) and with that I found it quite OK.

One just needs to avoid falling for the similarities with programming too much, and rather think in terms of signal and have the clock in mind.

The worst things are the tooling, e.g., I expected Quartus to crash or hang at any moment, I early wrote a TCL script to setup the project and FPGA pin mapping to be able to scratch the Quartus project at any time and just recreate it in seconds without losing any work (or my mind).

There's ghdl (open source) which I found quite nice, but that's only for virtual development and (at least then) had no support for getting out a bitstream to load onto a real FPGA, so often I used it for test benches and some quicker development tries before actually loading it onto the FPGA every so often.

I find VHDL unpleasant (and Verilog only slightly less so, even if it's the worse language) but the hard part for someone with a programming background isn't the language per se, it's learning how to design digital logic, which is very different from writing software.

Any university graduate-level fabrication lab class has the equipment to do this. A self-aligned, metal-gate process is relatively simple. You can probably build something akin to a 6502 in it.

The main issue is creating the masks. I'm not sure where you would get rubylith and the associated machinery for contact printing in this day and age.

As a side note: the thing stopping commodity VLSI is the CAD tools, not the silicon. Silicon runs are around $50K or so for an old node and Fab Shuttle/MPW(multi-project wafer) runs are often under $10K.

I don’t know if $60k sounds cheap to you, but I’d hardly call it a commodity.

Injection molds cost $50K all the time and are considered commodity.

Just because you, personally, aren't willing to spend the money doesn't mean something isn't a commodity.

The author misleads you with a point I brought up, it is not possible without globaliziation providing essential raw materials components that have no replacement unless that is your local environment. Spruce Pine has silicon that gives the US microchip supremacy that has dominated for the entire duration of manufacturing. It will never be commoditized that you can take off the shelf raw materials from anywhere locally and refine them. In the structure of globalism I linked to how google is allowing home designers to produce older technology chips.

https://www.electronicsweekly.com/news/business/diy-chip-10k... https://www.hackster.io/news/efabless-google-and-skywater-ar...

If you are interested in self-sufficient decentralized communities, microchips are not essential for a good society or long life. https://aeon.co/ideas/think-everyone-died-young-in-ancient-s... They're useful for being able to make non specialized hardware that can run general programs that many can support. Microchips do calculations and are more useful in scaling, analog computers can take some roles but it will be more wasteful to produce specialized hardware.

I don't know if vaccuum tubes need globaliziaton to make but you are not going to make decentralized microchips with local goods, they are not fungible raw materials like food.

I don't think it's inherent that doped silicon will stay the dominant microelectronics substrate and I think it's plausible that people will find new ways to grow it that don't require excellent raw materials.

Where is the evidence for this change or why is it plausible? Unless you have some information I don't, it has never been the case and there isn't a reason to expect it. I hope it can happen, but manufacturing shows no signs that we may make it from a more common material, if anything they will use an even rarer more difficult process because purity of materials is very important and the result of lower quality silicon is so bad that nobody uses it, the chip shortage and reliance on a few places isn't ideal but there is no alternative except not to use them, which is possible. There is a lot of interest for everyone to have it but its not plasible, it can be minized but the refinement is very important, and there isn't any reason for a small community to stop buying globally thir plans at the highest quality plants have better yields, better quality, and they will be more energy efficient. Homegrown parts will not even work because it relies on economies of scale.

However, it is plausible to not rely too much on microchips in general, a pot can control fan speed with older motors, but we lose brushless fans. You may really enjoy post collapse guides if you are interested in what can be made locally.

http://www.survivorlibrary.com/

There are great youtube videos on like primative technology as well that makes things from scratch, even steel cannot be made locally without the proper materials so there needs to be some sort of global/larger community unless they live in a resource rich environment (the US does not have metals like Eurasia does).

Making chips at home, by building the required setup from generic parts, is feasible. So is achieving nuclear fusion at home, by building a fusor.

Both are educational and cool, and neither makes economical sense.

I wonder what other processes could be used instead of photolithography to etch the silicon, deposit metal, etc? If you had a machine that started with a doped wafer, and worked one gate at a time, instead of a whole layer at a time, it would be way slower, but could, in theory be testable as it goes, and produce arbitrarily complex chips.

Also, I wonder what other materials might work, even if they are much slower, lower power, etc. Copper Oxide, for example?

I have similar questions. I wonder what wild alternatives can be substituted. Meaning, instead of thinking of making transistors on a silicon chip, can we make transistors on any other material or in any other fashion (say tapping into existing structures in nature) in a much easier way? Can we somehow exploit synthetic biology? Etc. etc. To replace the many assumed and developed processes and steps of the supply chain with much more feasible and easier approaches might result in a more efficient process in general.

Basically, we need functional understanding of all components, and hierarchical functional equivalents/isomorphisms. Aka "What is the end function of logic gates?" "To do X" "Are there simpler, easier, faster, more feasible structures that do X? Any way whatsoever? Does not need to relate to the current discipline or our established approahces" and iterate that question over all components and steps of the chip making process.

yeah you are onto something. massive supply chains have a ton of carbon footprint. which some people that doesn't matter but for someone like myself, i am a bigger fan of less carbon emissions. i wonder if there is a way we can build an etching machine and print chips somehow, the process seems a little clearer after watching this simplified video. i think it can be done, everything complex is just a bunch of simple steps, solve each step and get closer to the goal. might be fun to create a github type community where people push their ideas to a source control platform where others can chime in and give their input. so like open source chip manufacturing, kinda like how 3d printers started out with makerbot and other open source printer projects.

i think it can be done and it would be fun. we have to filter out people who have a vested interest in chip manufacturers because they may try to over complicate the process to protect their purse. so like a vouch system, where we know the people coming in have the right heart and won't purposely screw up moral

I think it's extremely unlikely that a small scale DIY process would be more energy efficient than using existing fabs.

> massive supply chains have a ton of carbon footprint

Are you talking about distribution? Because I would have thought the small size/weight of wafers would mean those costs would be fairly small. Maybe (silicon) packaging could be done locally, but even then packaged chips weigh little.

While energy, and thus CO2, is a significant part of solar cell production (because of the sheer scale), the attributed CO2 output of the chip industry is tiny compared to the commercial value of the chips produced.

so carbon tax would be effective in this scenario?

Current C-suite culture should suffice.

You can buy or rent Yokogawa modular machines for making chips. Fits in a room.

https://cdn.aff.yokogawa.com/9/400/details/minimal-fab-one-s...

*I added a reference link

Any idea what something like that costs?

It'd be really awesome if it could be done at home. We need the ability to make hardware at home just like we can download a compiler and make software at home. Computing freedom depends on it.