
A home-made lithographically-fabricated integrated circuit - DEFCON28
http://sam.zeloof.xyz/first-ic/#
======
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.)

~~~
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?

~~~
sevensor
I used to work in a fab. As far as I know, there's no acceptable way to remove
native oxide without HF. We do have another etch process -- dry etch -- that
uses plasma instead, but it causes surface damage, and you don't want that
under the gate. Also, dry etch chambers are a lot more work to maintain than a
fume hood where you do wet etch. Furthermore, dry etch has its own set of
hazards, and you have to deal with a lot more potentially toxic vapor.

~~~
sevensor
Thinking a little more outside the box, you might look into using germanium
instead of silicon. I don't know much about the germanium system, except that
it supposedly grows less oxide. You're still going to have to deposit and
remove oxide somehow, though, which means CVD reactors and silane. It's not
going to be easy to get away from explosive toxic gases and dirty processes.

~~~
kurthr
Not to mention DiBorane and Arsene... 1000C anneal cycles, teratogenic
photoresist ethers, UHV equipment, and muti-kW RF sources. It's possible to
demonstrate um scale MOS with a small lab, but not safely in anything
resembling a normal garage. Hoping to replicate a multi-$B process at home is
a fool's errand.

~~~
sevensor
While we're at it, a modern scanner costs many million dollars, weighs tons,
and sits on its own separate foundation on pilings that go down to bedrock so
that it doesn't pick up vibrations from the air handling systems. DIY it ain't
:)

~~~
DoctorOetker
what is a scanner in this context? what is its role?

or is this a stepper? or scanning electron microscope?

~~~
sevensor
A scanner is a photolithography tool like a stepper, except instead of
exposing the entire shot at once, it sweeps (scans) a narrow rectangular
exposure across the shot, and then steps to the next one. This allows for
lighter, more precise optics. Confusingly, there's a piece of standard office
equipment with the same name. Even more confusingly, Canon makes both kinds!
Be sure you call the right technician for service.

------
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...](http://sam.zeloof.xyz/wp-
content/uploads/2017/02/IMG_2917-e1522160324771.jpg)

Take a tour in a home fab:
[https://www.youtube.com/watch?v=TrmqZ0hgAXk](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](https://www.youtube.com/watch?v=XVoldtNpIzI)

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

~~~
Confiks
Yeah, I went a bit overboard in my amazement that this exploration into
building integrated circuitry with affordable tools was so well documented.
Such practical information and experience is hard to come by in world where
the manufacturing of integrated circuits has been iterated on with very
expensive machinery for at least 50 years.

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

[https://spectrum.ieee.org/semiconductors/devices/the-high-
sc...](https://spectrum.ieee.org/semiconductors/devices/the-high-school-
student-whos-building-his-own-integrated-circuits)

Impressive.

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

[https://www.youtube.com/watch?v=PdcKwOo7dmM](https://www.youtube.com/watch?v=PdcKwOo7dmM)

~~~
restalis
[5:16] _"...oh, I didn't die having go in there messing with the hydrofluoric
acid. My bones do feel a little gelatinous though."_

I'm not sure if I should admire or condone this kind of attitude in a science
related context.

~~~
henriquemaia
> I'm not sure if I should admire or condone this kind of attitude in a
> science related context.

It makes no difference whatsoever to the whole what you’ve pointed out here.

Throughout the video, she states she’s responding to critics. Her whole
attitude is of teasing those who accuse her of not knowing what she does
(calling her chips fake, etc).

When she says that, it’s perfectly clear that she’s being very (and I mean
very) sarcastic.

We can discuss if her use of sarcasm is useful or not, but then we will be
discussing the specifics of her presentation, not her skills at doing the
chemical process she just demonstrated.

Since this is a video about “Making Microchips at Home”; since she’s
responding to critics; I think we can allow her some room to throw some
sarcasm to the mix, even if it does not work out completely as intended.

On a side note: it would be nice if people on the internet would allow others
some “humanity"; by that meaning giving them room to err, like saying silly
things when they are annoyed — instead of nitpicking bits of unimportant
information.

The Internet is already too noiseful as it is.

~~~
ijin
Normally I would agree with you. But these days when anyone can find support
for, as well as buy, almost anything on the Internet our freedom to be
imprecise and still responsible has unfortunately diminished significantly.
That of course doesn't justify a lot of other comments, or attitudes, people
have to deal with when wanting to make something.

~~~
zaroth
> our freedom to be imprecise and still responsible has unfortunately
> diminished significantly

I disagree. The responsibility has and should always remain entirely with the
person taking the action. If speaking imprecisely on the Internet is a
liability then nobody can speak at all.

Random YouTube maker videos have virtually zero duty of care to their
audience.

I say _virtually_ because I could imagine a maliciously crafted video designed
to lull a watcher into inadvertently blowing themselves up, but even in the
case of a prank video which gives knowingly false/dangerous instructions I’m
still not sure of this is something people can or should be held liable for.

If you are handling dangerous chemicals, it is your own personal
responsibility to have proper tools, training, and certification to do so
safely. Being able to find false information on the internet doesn’t in any
way absolve you from the responsibility or shift the blame to someone else.

A moral/legal system which would shift liability to a random YouTube video has
a lot of highly undesirable side-effects in terms of stifling free speech, and
free exchange of ideas.

~~~
ijin
It's not really about liability, but whether it's warranted to object. You can
say whatever you want, but you can't expect others to not say what they want
back unless what you are saying is measured. Objecting to what other people
are saying isn't stifling of free speech, it is free speech itself.

~~~
zaroth
Yes, certainly, no one should expect anything they say or write to be beyond
reproach or free from criticism. That’s very different from saying they
shouldn’t be free to say it in the first place, which is how I (mis-)perceived
your initial comment.

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

------
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!

~~~
bleke
I'm interesting in this too and wondering why nobody did huge task and
compiling everything into one book, starting from refining materials to making
8051/Z80 era pc

~~~
bradyd
There is a book about building a toaster from scratch like this called "The
Toaster Project" [1]. The conclusion is that it's extremely difficult and
nearly impossible for even a simple device like a toaster. A computer would be
significantly more difficult.

[1] [http://www.thetoasterproject.org/](http://www.thetoasterproject.org/)

------
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.

------
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.

------
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...](https://harpers.org/archive/1998/11/the-radioactive-boy-scout/)

------
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.

------
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).

------
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](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/](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.

~~~
q3k
> The logic of how a CPU works is more interesting.

Maybe for you. I find silicon fabrication to be much more interesting.

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

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

------
Taniwha
Bravo!

------
mozumder
OK now grow your own SI wafers using repeated Czochralski process based on
silicon you made by melting sand.

~~~
archgoon
This seems to be a little silly. Sure, that'd be cool, but I mean, he didn't
claim to have manufactured his own oscilloscopes here either.

~~~
mozumder
Just putting out next step learning challenges. I'm loving what he's doing,
it's a great project, I hope he continues it by exploring different aspects of
it.

Other challenges include smaller lithography and CMOS fabrication using a
self-aligned gate process. But there are pitfalls ahead, including chemicals
that can kill with in trace doses...

I fabricated my own ICs as a teen in my freshman year of college as part of
our program, but that obviously wasn't at home. It was still awesome, just
going through the entire process.

