A home-made lithographically-fabricated integrated circuit

[ISL]

Awesome. For those considering exploring some of these steps in their own garage -- the chemistry is dangerous, perhaps HF in particular, as it doesn't hurt, it just kills you a few hours later.

Can you do this in a garage? Absolutely, but learn everything you need to know from an ensemble of safety-minded mentors before you strike out on your own.

It's not just about safety for you, proper disposal of these chemicals is essential for the many generations to come. Sometimes it is inexpensive, sometimes it is costly. You need to know how before you start, or it costs a lot more.

(Also, you can get someone else to pay for the hardware, the infrastructure, the material, the resists, the reagents, the safety training, and the waste disposal if you work/volunteer at a university's photolithography facility. They'll probably pay you, too.)

[jakeogh]

Nice HF technical overview: https://ehs.unc.edu/files/2015/09/hydrofluoricacid.pdf (tldr; nope; read it.)

I needed to dissolve(ha!) fluorite once. You can get it started by adding a few drops of conc H2SO4 to your beautiful aqua regia solution. It goes deeper red, some happy bubbles appear, and as long as it stays put, makes it's own "aqua nasty"(pg88) as you gently add your powdered sample.

I thought AQR+SA was called aqua nasty, but I cant get any hits other than this AA pdf with explicit HF added. Maybe an actual chemist can chime in, is there another name for the aqua regia +H2SO4 mix?

https://archive-resources.coleparmer.com/Manual_pdfs/28750-1...

[phkahler]

>> For those considering exploring some of these steps in their own garage -- the chemistry is dangerous, perhaps HF in particular, as it doesn't hurt, it just kills you a few hours later.

I was hoping that with 50 years of development behind us, the home fabricators could use less complex methods and less hazardous chemicals. In other words, can the folks who lived it help people like this by saying "If we had to do it over, I'd go about it like...."

Any suggestions? If you had to reboot the chip fab business on a budget what would be a more practical approach?

[Cerium]

I'm here to second the recommendation to work, volunteer, or take a class at a university. I took a class on MEMS at my university, and for only a few hundred bucks got access to a fully stocked lab with proper training and supervision. It was a good experience I would recommend to anyone interested.

[chaostheory]

> It's not just about safety for you, proper disposal of these chemicals is essential for the many generations to come.

Yes Gordon Moore created a superfund site or two in California.

[crankylinuxuser]

And I would argue that individuals have the right to commence with research and creation. Science is not 'easy stuff that harms nobody'. The Curies suffered radiological poisoning but furthered chemistry and physics a great deal. I would think that "computer science" has mollified people in thinking that science is painless, harmless venture of fun exploration. Go read up about the countless physicists and chemists who tried to crack fluorine.

If you are a scientist, and not in a sciency-y setting (lab), have a laminated clipboard stating chemical threats, electrical threats, biogenic threats, and particulate threats.

You may end up killing yourself. If you do, you did so in the name of science. Please, don't have others die because you failed to properly notify first responders of a threat.

[88e282102ae2e5b]

I understand why it's necessary, but I was shocked that he uses piranha in his home garage. I cannot echo the above sentiment enough.

[Spooky23]

Thanks for saying this. I worked for a few years at a semiconductor fab r&d facility. (As a tenant) Seemingly everything associated with this stuff is toxic and polluting. The old timer war stories include stuff like accidental releases that stripped paint from all of the cars in the adjacent lot.

Nasty stuff — the wisdom promoting garage stuff like this is questionable. :)

[nightbrawler]

For those curious about the HF danger mentioned above, Wikipedia has an interesting (and scary) summary:

https://en.wikipedia.org/wiki/Hydrofluoric_acid#Health_and_s...

[Itsdijital]

Good 'ole HF

http://blogs.sciencemag.org/pipeline/archives/2004/03/03/thi...

[Geee]

Besides IC fabrication, you can also use HF for making mouthwash: https://www.youtube.com/watch?v=gHoUCyQR7h8

[mozumder]

And then you have Phosphene gas used to dope silicon, where people have died changing empty supply tanks.

[Confiks]

Have a mini-course into maskless photolithography[1][2], and find out how an old DLP projector combined with some advanced optics can yield this: http://sam.zeloof.xyz/wp-content/uploads/2017/02/IMG_2917-e1...

Take a tour in a home fab: https://www.youtube.com/watch?v=TrmqZ0hgAXk

His website and Youtube channel are so richly filled with knowledge that so desperately needs to be in the public domain, instead of being locked in corporate structures.

[1] https://www.youtube.com/watch?v=XVoldtNpIzI

[2] http://sam.zeloof.xyz/maskless-photolithography/

[analognoise]

"His website and Youtube channel are so richly filled with knowledge that so desperately needs to be in the public domain, instead of being locked in corporate structures."

All of this information is public domain, what are you talking about? This is extremely well understood stuff.

[femto]

IEEE has a background piece for those (like me) wondering "who is this guy?"

https://spectrum.ieee.org/semiconductors/devices/the-high-sc...

Impressive.

[thefourthchime]

His inspiration, Jeri Ellsworth is just (if not more) impressive. Check out her youtube.

https://www.youtube.com/watch?v=PdcKwOo7dmM

[innovator116]

Impressive to replicate silicon semiconductor process. But wouldn't it be more feasible to develop as good enough process node, flexible, thin film semiconductor devices? Have been observing developments of plastic based transistors, inks, processes like nanoimprint lithography, Cleanroom in a STEM microscope and Chad Mirkin's Tera Print system. Can a small scale nanfab emerge using tech such as Nano-Ops http://nano-ops.net/nanoscale-printing/ ?

I imagine flexible, thin film, large panel based semiconductor SoC. It will not be just a mere microcontroller or IoT node, but a full fleged computing form factor. Think your wall as big plastic computer.

[bb88]

So there is reel to reel OLED screen technology out there (basically a printing press for OLED screens).

http://www.flexolighting.eu/ (These guys have some pictures of the process).

It's probably also possible to print transistors directly. Here's a paper from 2017 that outlays that process.

https://www.nature.com/articles/s41598-017-01391-2

[iancmceachern]

This has lots of advantages. It removes the need for smaller and smaller chips, it spreads the heat out (a major limitation in electronics packaging today), and it adds a lot of new possibilities.

It's a giant pcb and ic combined, both custom to each other and the application.

[Taniwha]

I'd rather see that done with a 3d-printing process that way rather than making giant flat things you end up making far more compact bulk 3D things

[sjclemmy]

When I read things like this I start to think about the following question: Given no technology at all (i.e. after an apocalypse!), how would one go about creating a computer (as we know them). What sort of knowledge would you need? The science of these things is basically multi decades of trial and error in various disciplines. Imagine a manual that explained how to create everything from scratch!

[terminado]

Geeze, I though you needed a clean room to do this kind of work. I guess, being a hobby, with less concern for effort, loss of product, or cost versus profit, one might summon the will to try, try again, when confronted with botched fabrication runs.

Even with millimeter-scale components, I'd still think dust and debris could be a real problem. Is it just that 12 hour runs are short enough to just accept an imperfect production output, since it's a personal project, or is dust not as big a deal at this scale as I'd imagine?

[AstralStorm]

You do not need a cleanroom, just some laminar airflow to prevent dust contamination. That is easy to achieve with a bunch of fans and lab clothing.

Static electricity damage is prevented by grounding everything. (Important during lithography.)

The hard part is getting a reliable plasma oven and the requisite chemicals plus running the process to reliability.

[anfilt]

The smaller you go the more worried you should be about dust, and particles. Also the more layers to your process. Also no mention of yield.

[fizixer]

I was looking for how he managed the clean room or did he not go too small. Found the answer in the IEEE article shared by another commenter (he didn't go below 10 micron tech node).

But now I have a follow up question, if getting a clean room is obviously harder, isn't "clean box" more doable? E.g., if you line up a bunch of tables, and put a long box on top that acts like a poor man's assembly line. The insides of that box are only accessible through gloves that are attached to holes on the sides of the box, and plenty of glass windows to look inside (kinda like the box in movie 'Life'). How cost effective and feasible (i.e., gets the job done) would that be compared to a clean room? maybe you could go sub-micron with it if not sub-100nm.

[sonium]

Also if you don't really care about yield, many things are not that critical. I did a PhD in semi-conductor physics, and most processes for silicon are actually surprisingly robust (compared to processes of any other material). Also many things are just done the way because people know it worked before, which does not mean you can't use less fancy equipment and it would still work.

[Gibbon1]

What I understand is while semiconductor machines live in clean rooms, the wafers never leave the hyper clean environment inside the machines. And when wafers move from machine to machine it's via sealed enclosures.

Using long plastic box with a 3 axis gantry inside might be doable.

[sanxiyn]

"clean box" is already used. It's called FOUP: https://en.wikipedia.org/wiki/FOUP

[basementcat]

I predict a future Hacker News submission titled "I turned my garage into an EPA Superfund Site"

[kens]

You should really read "The Radioactive Boy Scout", about a teenager who attempts to build a nuclear reactor. The EPA ends up dismantling his shed in moon suits.

https://harpers.org/archive/1998/11/the-radioactive-boy-scou...

[DoctorOetker]

The Radioactive Boy Scout and Sam Zeloof are two complete opposites of the spectrum though

[raverbashing]

Well we had that Boy Scout once... not sure it turned into an EPA Superfund site though

[shortoncash]

This is incredible work. I would have loved to have attempted this when I was in college. The field seemed so inaccessible, and now it makes me happy to see some homebrewer accomplishing things like this.

[dschuetz]

That's great! Are we anywhere near to making homebrew ICs on silicon at home? Yes, apparently we are! But it seems we are still far away from DIY kits, or even complete prototyping devices (like 3D printers).

[olskool]

If he could get feature size down to 10 microns someone might have a shot at making a microprocessor.

[AstralStorm]

At that scale his hacked together (amazingly cheap) optical lithography equipment will not serve. (See how well it did with 1um lines. That is the main problem.) Nor especially the photoresist process.

Perhaps it can do 5um with a different resist.

[agumonkey]

I'd gladly reproduce some vintage style computer with a large number of his ICs. Just for fun :) a B5000 maybe

[orbital-decay]

Can the process be streamlined into a single amateur-friendly device/lab? Yes, I mean a chip printer, as a commercial product.

[Nokinside]

Chip printer that would make IC's that are better than what amateur can make from readily available cheap components on a PCB board would be used in the industry first.

There is small number of field-programmable analog array (FPAA) products and FPGA/FPAA hybrids in the market. I hope they become better and more available (never used one myself).

[pasabagi]

I think the chemicals would be the rub. HF is very nasty, as is 'piranha solution'. Both are extremely corrosive, obviously - so it would be hard to build a 'printer' that could deal with the handling and disposal.

Not to mention, a lot of the dopants are pretty nasty too.

[syntaxing]

Instead of using all these dangerous chemicals, can you use use an alternative like Ion Beam Etch (IBE) or some sort of plasma etching system (given that a person can build one and has the money for everything like turbopumps and grids)? Or is it mandatory to use something like HF to etch?

[kurthr]

Lots of comments on the previous article (before he had a chip to test) as well.

https://news.ycombinator.com/item?id=15990766

[baybal2]

I remember, there is a Swiss guy in HK who is trying to reanimate an abandoned nineties era fab for use by of opensource electronics.

[coldacid]

Cheers to this kid's drive and inventiveness, but I won't be at all surprised when his house becomes a Superfund site.

[ChrisGammell]

Had a chance to interview Sam last week, he's as bright as you'd assume: https://theamphour.com/390-an-interview-with-sam-zeloof/

[Tistel]

There are less dangerous ways to explore "building a CPU from scratch" that hit on the really interesting bits. "Digital Computer Electronics" by Malvino and Brown. You are given logic gates (and, or, nor, nand etc) and build up from there to a working CPU. The articles referenced about HF are terrifying. I am a programmer, but, have worked in a chemistry lap. Its just endless stinky stuff that will kill you in a variety of ways. The logic of how a CPU works is more interesting.

[vaxin]

Uoou... now this is really cool, this guy is incredible :)

[John_KZ]

Lovely, I've always wanted to do something similar.