alt.hn

12/7/2025 at 3:03:09 AM

Z2 – Lithographically fabricated IC in a garage fab

 https://sam.zeloof.xyz/second-ic/

by embedding-shape

12/7/2025 at 5:56:50 AM

The timing of this share is crazy, since I was just looking around a few days ago to see if there were any guides or even kits for doing photolithography at home. It's part of my mission to demystify modern technology for my kids. I couldn't find anything, so this is excellent to see. Far too complex for my kids ages, but it might be cool to replicate at least part of this amazing project when they're older.

by mwcz

12/7/2025 at 7:07:29 AM

There is a great video on creating lithographic masks on Ben Krasnow's Applied Science channel - https://youtu.be/YAPt_DcWAvw?si=RXaS-GY7czqo_TJZ

The photographic steps are pretty accessible.

by bpye

12/8/2025 at 12:40:39 AM

Was just going to post this. Ben's channel is a treasure trove.

by jcims

12/7/2025 at 2:48:48 PM

Wonderful, thank you!

by mwcz

12/7/2025 at 8:29:28 PM

The Hacker Fab [1] project at Carnegie Mellon is creating and publishing guides to building simple fab equipment including photolithography and a sputtering system. For somewhat more complex equipment, I appreciate [2] from the founders of InchFab [3].

But maybe the easiest way to do (very low resolution) photolithography at home is to use dry film photoresist, which is like tape you can stick onto a copper PCB you then expose and etch; a cheap roll is ~$20 from eBay/Amazon.

[1] https://docs.hackerfab.org/home [2] https://dspace.mit.edu/handle/1721.1/93835 [3] https://www.inchfab.com/

by alted

12/8/2025 at 12:02:32 AM

They also have a discord server that seems pretty healthily active (I'm a long time lurker)

by junon

12/7/2025 at 6:54:42 AM

Cyanotype Paper is safe fun for kids to try Sun printing silhouettes.

Another project is growing large salt crystals in saturated solution.

The Unitech Electric Static Wand Toy off amazon was also popular last year (poorly built mini Van de Graaff generator.)

Glow in the dark wall paint and a 5 second strobe light is also a classic silhouette demo.

Could also look for linear polarizing sheets, thermochromic sheets, and "Magnetic Viewing film".

Some will like this stuff, others only want to stare at a screen. =3

by Joel_Mckay

12/7/2025 at 2:45:06 PM

Thank you, those are some awesome ideas. We've tried about half of them, but the rest are going straight on the list. Much appreciated.

by mwcz

12/7/2025 at 6:57:15 AM

Silk screen printing is probably the easiest way to introduce the concepts to kids. There are a lot of maker spaces/artist collectives and classes that have the basic tools and resources to do it.

by duped

12/7/2025 at 11:42:48 AM

You could also try to replicate something like the Monster 6502: https://monster6502.com/

It's not lithography, but you can build a working processor out of small surface mount chips, and you can solder these chips with lead-free solder. That seems very achievable for a motivated engineer, and probably involves much less toxic chemicals?

by snek_case

12/7/2025 at 7:59:11 AM

Or even gel plate printing, where you get to build multiple layers, one of them being a laser printed photo that is used as a resist.

by semi-extrinsic

12/7/2025 at 5:03:33 AM

Replicating late 70s chip fab in one's parents' garage. Incredible honestly, given that the microprocessor is probably the most complex human invention.

by N_Lens

12/7/2025 at 6:23:18 AM

This is impressive work. Every time I see hobbyist-scale semiconductor projects, it reminds me how much innovation still happens outside big labs. Curious how far this approach can scale.

by Simplita

12/7/2025 at 9:08:46 AM

The semiconductor device industry and Silicon Valley would have never appeared if the early companies working in this field would have been controlled by people obsessed about secrecy and "IP protection".

During the fifties and the sixties, and even until the early seventies, it was common for everyone to publish research papers very unlike those that are published today, where the concrete information is minimal.

In the early research papers about semiconductor devices and integrated circuits, it was normal to give complete recipes, including quantities of chemicals, temperatures and times for the processing steps and so on. After reading such papers, you could reproduce the recipes and make the device described and you could measure for yourself to see how true are the claims presented in the paper.

That open sharing of information has led to a very quick evolution of the semiconductor technologies during the early years, until more traditional business-oriented management has begun to restrict the information provided to the public.

It is said that such sharing of information still exists in China in many fields, and it is the source of their rapid progress.

by adrian_b

12/7/2025 at 11:42:13 AM

> until more traditional business-oriented management has begun to restrict the information provided to the public.

Curious to know why you think this cutthroat approach is 'traditional'. Is there another historical background to it? Every account that I've seen, including the origin story of free software (at MIT) and even the rest of your own explanation, seem to suggest that such institutionalized confiscation and hoarding of knowledge is a recent phenomenon - since about the 70s. Am I missing something?

by goku12

12/7/2025 at 8:41:39 PM

That's a fair and good interjection. The truth is probably that at society scale, both approaches are traditional.

The open sharing approach is traditional for research and academia, while the information restricting approach is traditional for business-oriented thinking.

So, a young field will typically start out fairly open and then get increasingly closed down. The long-term trajectory differs by field, and the modern open-source landscape shows that there can be a fair bit of oscillation.

We're seeing the same basic shape of story play out in generative AI.

by nhaehnle

12/8/2025 at 8:27:51 AM

Sounds good enough. Thanks!

by goku12

12/7/2025 at 4:32:59 AM

cant wait to see what his latest venture will bring about

https://atomicsemi.com/

allegedly jim keller is one of the investors!

by webdevver

12/7/2025 at 9:46:48 AM

Does that name make childish Americans giggle in the same way as this childish Brit?

by jimnotgym

12/7/2025 at 1:56:39 PM

A semi in British slang is a partially erect penis. I guess “atomic semi” would sound like “partially erect micro-penis” to a Brit.

by christophilus

12/7/2025 at 6:31:45 PM

I couldn't decide between micro-penis, and some kind of comic-book hulk type appendage. But your description was very eloquent, so I'll go with that.

by jimnotgym

12/7/2025 at 12:51:19 PM

Not American, not a Brit here. Care to explain?

by kkkqkqkqkqlqlql

12/7/2025 at 1:31:44 PM

I'm neither either, but Jim Keller is a (the most?) legendary microprocessor engineer, and responsible for so much in the semiconductor industry. Kind of what Messi is for football, but for processors.

by embedding-shape

12/7/2025 at 10:24:34 AM

no, we don't have that slang.

by djmips

12/7/2025 at 12:55:00 PM

Had no idea he'd started a company, always found his blog posts so inspirational. Really hope he succeeds!

by zipy124

12/7/2025 at 3:46:16 PM

This isn't just awesome, this is world changing. Fabricating our own hardware at home is the hardware equivalent of writing our own free software at home. This will help ensure our long term computing freedom.

by matheusmoreira

12/7/2025 at 3:51:14 PM

Personally I agree, but the world doesn't seem to. Their first project (https://sam.zeloof.xyz/first-ic/) was all the way back in 2018, and it doesn't seem like it changed all too much (yet), while since I read the first blog post in 2018, I also thought we would have reached a much more mature DIY ecosystem by now.

Don't get me wrong, I'm excited too about it, and can't wait to personally do some experiments as well, although not at the same scale. But I'm not sure it's world changing, at least until I've actually seen any changes :)

by embedding-shape

12/7/2025 at 6:38:00 PM

Finicky chemicals and relatively expensive equipment. But he’s founded a company with Jim Keller. We occasionally see them post a photo with zero context, but we do know some things. Like they are targeting lots volume stuff and basically building fab equipment. But not much more.

by shash

12/7/2025 at 6:26:57 PM

It's really amazing, great work! And please keep sharing progress and, if you want, how can other people follow on your footsteps!

by BiraIgnacio

12/7/2025 at 7:10:35 PM

It's not my work!

by matheusmoreira

12/7/2025 at 1:49:26 PM

I was like, this seems like a small machine could automate a lot of it, now that the number of steps are down to around what ECN2 film dev requires…

Of course, that’s what they are doing it seems! https://atomicsemi.com/

by buildbot

12/7/2025 at 1:28:24 PM

remember when JLCPCB became popular a few years ago and completely flipped hobby electronics upside down? I don't know how possible it is but it would be really cool if that happens in a few years with semiconductors. it's kind of mad that they've dominated our lives since the 1970s but you can only make them if you're a large company with millions of dollars (or several years, a big garage and lots of equipment as seen here). or tiny tapeout.

by unleaded

12/7/2025 at 5:08:02 PM

It's not technologically feasible unless plastic aka flexible ICs take off.

by mepian

12/7/2025 at 6:01:13 PM

Why?

It seems to me that if there were as much of a customer base for custom ICs as there is for PCBs, a fabricator like TSMC could easily offer a batch prototyping service on a 28 nm node, where you buy just a small slice of a wafer, provided you keep to some restrictive design and packaging rules.

by mitthrowaway2

12/7/2025 at 6:43:53 PM

They already do offer that - it’s called a multi-project wafer or MPW. But it’s prohibitively expensive on a per-chip basis. It’s mostly used for prototyping or concept proving and not for commercial use.

One problem is, you need to create a photolithography mask set for any volume size of fabrication and those aren’t cheap. But that’s far from the _only_ problem with small volume.

by shash

12/7/2025 at 3:49:16 PM

This is an absolutely vital development for our computing freedom. Billion dollar industrial fabs are single points of failure, they can be regulated, subverted, enshittified by market forces. We need the ability to make our own hardware at home, just like we can make our own freedom respecting software at home.

by matheusmoreira

12/7/2025 at 4:34:22 AM

should have added this happened in 2021

by itsthecourier

12/7/2025 at 6:18:06 AM

oh man, I remember hearing about this back then and I got excited that there had been an update. From what I hear he’s gone off to college now but will hopefully be back to cooking up semiconductors once he graduates

by jedbrooke

12/7/2025 at 6:41:52 AM

He founded a company with Jim Keller called Atomic Semi since then.

by eco

12/7/2025 at 7:21:15 AM

Although this is in 2021, it's great to see that Sam Zeloof also made Atomic Semi [0].

A display of "just doing things", no permission needed and no need for barriers and red tape.

It is another reason why I have huge promise for Substrate [1] founded by James Proud (UK native moved to US) another display of "just doing things".

However in Europe and the UK, it's "this law allows you to do this, this and this", "we've changed the law, here is a massive immediate fine", "ban encryption" (this nearly happened), "ban maths", "we are the first to regulate and ban this".

It is no wonder the US will continue to be great at building things.

[0] https://atomicsemi.com/

[1] https://substrate.com/

by colesantiago

12/7/2025 at 9:31:17 AM

It’s also worth seeing how many US superfund sites are on former chip fabs. Intel, AMD, Fairchild etc. all just dumped things down the drains.

Regulations can be bad but they can also stop environmental disasters from happening.

by iNerdier

12/7/2025 at 11:57:23 AM

> Regulations can be bad but they can also stop environmental disasters from happening.

It makes me wonder how bad the situation is, when you feel the need to start your sentence with 'regulations can be bad', while corporations fight you for their right to release PFAS into your drinking water sources.

by goku12

12/7/2025 at 7:42:45 AM

Of note, Sam’s co-founder in Atomic Semi is none other than Jim Keller (!)

by nighthawk454

12/7/2025 at 1:20:15 PM

Is the "regulation bad" / "Europe bad" angle actually relevant here, or did you just take the opportunity to use this thread as your soapbox?

by perching_aix

12/7/2025 at 8:13:01 AM

As much as I hate to say it Substrate is probably a fraud

https://www.reddit.com/r/Semiconductors/s/jpuI772PJB

If Europe has an overregulation problem, the US may also have a grifter problem

by LarsDu88

12/7/2025 at 9:21:40 AM

I wonder if the pipeline is fully operational? US Grants -> investor -> scam company-> ?????

by actionfromafar

12/7/2025 at 2:36:03 PM

Current US president pardoned Trevor Milton, ceo of fake hydrogen car company Nikola.

Right now its ok to be a fraudster so long as you make at least a billion dollars doing the fraud.

by LarsDu88

12/7/2025 at 4:49:58 AM

Awesome! I wouldn't have thought that it is possible to make ICs in a garage. Of course it requires a lot of knowledge, etc. But still, not a multi-billion dollar clean room with specialist equipment.

by GianFabien

12/7/2025 at 9:19:07 AM

You could make in a garage some decent analog integrated circuits, e.g. audio amplifiers or operational amplifiers or even radio-frequency circuits for not too high frequency ranges.

However you cannot make useful digital circuits. For digital circuits, the best that you can do is to be content to only design them and buy an FPGA for implementing them, instead of attempting to manufacture a custom IC.

With the kind of digital circuits that you could make in a garage, the most complex thing that you could do would be something like a very big table or wall digital clock, made not with a single IC like today, but with a few dozen ICs.

Anything more complex than that would need far too many ICs.

by adrian_b

12/8/2025 at 7:56:19 AM

Not true. You are confusing "digital" with "microprocessor". You wouldn't be able to do any single-chip microprocessor, of course, but something like 74181 is very doable at this scale, and building a 1970s-era computer out of a few dozen of these is something enthusiasts still do. The main problem isn't logic, it's memory - memory needs density (thin film magnetics anyone?).

Then, of course, if by "useful" you mean "commercially viable", it is indeed not going to be competitive against either TSMC or your local 500nm foundry ever.

by tliltocatl

12/8/2025 at 9:59:09 AM

A CPU made with ALUs like 74181 would take alone a PCB of ATX or eATX size densely populated with integrated circuits and consuming much more power than an entire computer consumes today, while being slower than a tiny microcontroller with a cost of less than a dollar, which also includes enough memory for a practical application.

I call such a CPU as not useful.

It can be a very useful experience to design such a CPU, but you can simulate the design in a logic simulator and you gain nothing by building it.

As a valuable computer building experience, it is more useful to use much older components than digital integrated circuits, where you can see nothing without special instruments, e.g. you can build interesting computer blocks, like adders, registers, counters etc., made with electromechanical relays or with neon glow lamps, where you can see with your eyes how they function.

by adrian_b

12/7/2025 at 11:59:32 AM

What are the factors you expect to limit the integration scale in a garage fab?

by goku12

12/7/2025 at 6:12:00 PM

Variance, data rate/cost, and lithography.

You can do lithography small but slow and expensive. But small means you need a stack, which is even more expensive. At small sizes, defectivity/variation are really difficult.

So if you want a paradigmatic shift, you need low cost patterning, and the best way I can see is to use clever chemistry and a much different design style.

by brennanpeterson

12/8/2025 at 8:27:03 AM

Don't you think that a lot more improvement in variability and integration can be achieved with better optics? (for the photolithography, of course. I don't remember what they used for plasma etching and ion implantation.) I don't believe that they have explored a lot on that front yet.

> So if you want a paradigmatic shift, you need low cost patterning, and the best way I can see is to use clever chemistry and a much different design style.

Is that a speculation, or do you have a more concrete idea about what needs improvement and how? I'm especially curious about the 'much different design style' part. Could you elaborate that?

by goku12

12/7/2025 at 11:48:23 PM

I heard of one intriguing alternative to photo lithography. Microfluidic channels in a plate (injection molded). I saw a couple research papers in 2021.

by FarmerPotato

12/8/2025 at 12:15:05 AM

This is great!

I started programming on an 8 MHz Mac Plus in the late 1980s and got a bachelors degree in computer engineering in the late 1990s. From my perspective, a kind of inverse Moore's Law happened, where single-threaded performance stays approximately constant as the number of transistors doubles every 18 months.

Wondering why that happened is a bit like asking how high the national debt would have to get before we tax rich people, or how many millions of people have to die in a holocaust before the world's economic superpowers stop it. In other words, it just did.

But I think that we've reached such an astounding number of transistors per chip (100 billion or more) that we finally have a chance to try alternative approaches that are competitive. Because so few transistors are in use per-instruction that it wouldn't take much to beat status quo performance. Note that I'm talking about multicore desktop computing here, not GPUs (their SIMD performance actually has increased).

I had hoped that FPGAs would allow us to do this, but their evolution seems to have been halted by the powers that be. I also have some ideas for MIMD on SIMD, which is the only other way that I can see this happening. I think if the author can reach the CMOS compatibility they spoke of, and home lithography could be provided by an open source device the way that 3D printing happened, and if we could get above 1 million transistors running over 100 MHz, then we could play around with cores having the performance of a MIPS, PowerPC or Pentium.

In the meantime, it might be fun to prototype with AI and build a transputer at home with local memories. Looks like a $1 Raspberry Pi RP2040 (266 MIPS, 2 core, 32 bit, 264 kB on-chip RAM) could be a contender. It has about 5 times the MIPS of an early 32 bit PowerPC or Pentium processor.

For comparison, the early Intel i7-920 had 12,000 MIPS (at 64 bits), so the RP2040 is about 50 times slower (not too shabby for a $1 chip). But where the i7 had 731 million transistors, the RP2040 has only 134,000 (not a typo). So 50 times the performance for over 5000 times the number of transistors means that the i7 is only about 1% as performant as it should be per transistor.

I'm picturing an array of at least 256 of these low-cost cores and designing an infinite-thread programming language that auto-parallelizes code without having to manually use intrinsics. Then we could really start exploring stuff like genetic algorithms, large agent simulations and even artificial life without having to manually transpile our code to whatever non-symmetric multiprocessing runtime we're forced to use currently.

by zackmorris

12/7/2025 at 5:04:31 AM

(2021)

by pinewurst

12/7/2025 at 3:25:14 PM

Awesome!

by r2ob

12/7/2025 at 3:52:18 AM

Love this stuff.

Followed a couple of links and ended up on his brother's page, reading about another example of the anti-immigrant insanity that's taken hold of this country: https://adam.zeloof.xyz/2025/04/01/karim/ . So sad.

by foobarbecue

12/7/2025 at 6:20:03 AM

It’s heartbreaking.

by dented42

12/7/2025 at 9:17:29 AM

The US concentration camp industry is booming though.

by actionfromafar

12/7/2025 at 9:46:08 AM

I’m curious on the details. Isn’t marrying a citizen an instant path to residency and presumably rather quick way to get authorized for work? Are they holding him for having previously been in the states on an expired visa?

by teaearlgraycold

12/7/2025 at 9:51:59 PM

I don't know about this particular case, but ICE are grabbing people right out of naturalization hearings these days. Anything to try and hit that deportation quota.

by foobarbecue

12/7/2025 at 4:23:10 AM

[dead]

by ohbrother

12/7/2025 at 8:46:34 AM

Enforcing the law is not anti-immigramt insanity.

by charcircuit

12/7/2025 at 9:26:16 AM

The enforcement isn’t the insanity, the law is.

by taneq

12/7/2025 at 10:23:01 AM

The enforcement is the problem if it is not secure legally. If you want to handle it with an iron fist like a dictatorship sure you can create laws to that effect, but there should be some human values on the books that makes those laws humane.

by pastage

12/7/2025 at 5:34:42 PM

Considering practically every concept has the concept of a temporary visas, it must not be that insane of a concept.

by charcircuit

12/7/2025 at 10:16:37 AM

It's basically an objective fact at this point that excessive immigration is really, really bad, just look at all the politicians flipping sides on the issue. Look at the stats on European countries with the highest immigration rates vs those with the lowest (e.g. Poland)

by oilkillsbirds

12/7/2025 at 1:58:41 PM

Then maybe do something to reduce the causes if it? Recently, China has done more to reduce immigration to Europe than Europe has.

by mcdonje

12/7/2025 at 11:29:41 AM

By what metric are you looking at european countries and determining Poland is doing the best? If given the choice between say Ireland and Poland, which place would you prefer to live?

https://www.statista.com/statistics/1541464/europe-quality-l...

https://www.visualcapitalist.com/ranked-european-countries-w...

by jjk166

12/7/2025 at 11:56:03 AM

Look at RATE of growth (GDP, employment, safety, etc.) since immigration started getting bad in places like the UK - compare it's growth directly to the UK, or even the entire EU

by oilkillsbirds

12/7/2025 at 12:14:44 PM

I’m no expert, but reducing something as complex as a whole country’s economic outlook to just the variable „immigration“ seems like an oversimplification to me.

by adrianN

12/7/2025 at 12:27:44 PM

Two things:

* developed countries obviously develop slower than developing ones. Is easier to improve if your economy is shit especially if you join a union of more advanced countries.

* polish immigration actually skyrocketed recently since Russia invaded Ukraine. It didn't harm employment, safety, growth rate or anything else yet.

by integralid

12/7/2025 at 4:17:17 PM

2025 GDP growth for Poland is projected for 3.2 to 3.8%; for Ireland it's projected to be 10 to 11%. Poland's unemployment rate is up in 2025 from 2019, Ireland's is down. Poland's crime rate remained relatively constant in the period from 2018 to 2021 at .71 per 100k while Ireland's dropped over the same period from .81 to .44 per 100k.

by jjk166

12/7/2025 at 11:11:43 AM

> Enforcing the law is not anti-immigramt insanity.

Interesting you mention that, a few threads ago you were adamant that the EU wanting to enforce their speech laws on Twitter was 100% anti-free-speech insanity though.

It would seem that for you the insanity of the sheer fact of enforcement (since you clearly weren't talking about the character of enforcement) depends on your underlying sentiment on the given topic. Is that really intentional on your part? Sounds a bit perilous to me reasoning wise, if so.

Or did you simply change your mind since our last discussion?

by perching_aix

12/7/2025 at 5:12:54 PM

There is a difference between the US enforcing visas within the borders of the country and the EU using their laws to affect an American website, allow slurping up data of Americans living in America outside of the EU's jurisduction. America already went to war to stop Europe from ruling over us. The legality of operating every jurisdiction is going to be more complicated due to having to deal with unreasonable demands of foriegn countries or contradicting laws. It's much more complicated than a country enforcing who can be within their borders with visas where the US has clear jurisdiction. If you were to ask me if I think X should respect US law like the DMCA I would say they should absolutely be following US law.

by charcircuit

12/7/2025 at 7:34:18 PM

So if Twitter complied with the demands such that flagged EU-illegal content still remains available to non-EU (e.g. US) visitors, thus not removing anything on the demands of a foreign jurisdiction, in your eyes it would suddenly no longer be a case of "anti-free-speech insanity"?

Cause the whole "they're ordering around an American company" defense falls apart pretty quickly when said American company also operates (read: is accessible from) within EU borders, and in general can be used by citizens of EU member states (independent of their location).

by perching_aix

12/8/2025 at 1:13:13 AM

I believe that would be a reasonable solution, but at the same time I would feel bad that the EU has elected people to do such a thing to their people, but ultimately it's not my problem that they got into this state and have a worse version of X.

by charcircuit

12/7/2025 at 9:54:12 AM

[dead]

by YouAreWRONGtoo