
A High School Student Building Integrated Circuits - rbanffy
https://spectrum.ieee.org/semiconductors/devices/the-high-school-student-whos-building-his-own-integrated-circuits
======
ChuckMcM
Fun times. It is fortunate he has the means to pursue this interest, I would
have been so jealous of him when I was in HS!

I wonder what he is using to do metalization. There is the sputtering setup
and the etching setup. Some nasty stuff involved in that. You can of course do
quite a bit with polysilicon conductors but if he wants to do more useful
things (as opposed to 'look it wiggles!' sorts of things) I'm guessing he will
need some permits from the city :-). There is a reason nearly all the old fab
sites in the bay area coincide with superfund cleanup sites :-(.

~~~
wrycoder
I worked in small scale fabs back in the day. One and a half inch wafers. It’s
not nearly as hazardous as you make out, but it does require training in
chemistry. I’m a physicist, but I also did a pre-med, so I had the necessary
chemistry background to be safe.

Sputtering requires a small amount of high vac equipment - diffusion pump plus
LN cold trap is fine. Sputtering titanium plus gold is straightforward and
non-toxic. Etching the pattern requires small amount of aqua regia, which is,
of course, a strong acid, but can be easily neutralized to non-toxic by-
products. Aluminum evaporation and etching is even easier. The complexity and
cost comes in four areas: nanoscale features, large wafers, high throughput,
and a process that doesn’t need professional chemists to perform.

~~~
kurthr
Yeah, but doing it without a lab makes it a lot more difficult to do safely
and with multiple likely dangerous (toxics, oxidizers, mutagens) byproducts
(including the Si dopants) doing it at home is sketchy. Could one person do it
in something the size of a garage? Yes, I think 20-40 probably do every year
in a university clean room. But building that for a single person is an
exercise in both chutzpah and perhaps (toxic) waste. It's a lot more tempting
to cut safety corners when you're doing it for the first time, and haven't
made THAT mistake yet.

There is a manual for it though (thanks abecedarious).

[http://nanofab.caltech.edu/images/stories/classes/aph9/Aph9_...](http://nanofab.caltech.edu/images/stories/classes/aph9/Aph9_Manual_CurrentVerNov2014.pdf)

~~~
wrycoder
Absolutely right. This isn't something anyone should even contemplate in the
kitchen! If they are thinking about it, then they don't know what they don't
know. Experience in chemistry is needed, and that's unfortunately a lot rarer
now in the US than it was 50 years ago. People (and governments) have
developed a (mostly unwarranted) fear of it.

The minimum processing requirement (aside from the furnaces and metallizing
equipment etc.) is a polyethylene sink hood with at least 100 ft per min flow
and a neutralizing tank connected to the drain line, along with fume exhausted
chemical storage below. If you can't acquire or build that, you shouldn't
proceed further. I did a lot of commercial work in a three foot hood with a
large Corning hotplate.

You also need an arrangement to recycle your organic solvents.

~~~
Pica_soO
People are not this dumb- they have come to associate large scale chemical
(aka chemistry) processing with environment and health issues- and although
nobody in the various industries likes to hear it- they are usually right.
Every city has some paved over "dead" zone from the 50s and 60s, before we
learned to offshore the burden to third world countrys.

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nraynaud
Not to be a grinch, but I followed a lot of his videos, and I think he has not
yet actually put 2 transistors on the same die, it's the technological
threshold for an IC. I think he is working on making patterns (and that's
interesting, because nobody is working on cheap masking), he made some
individual transistors with masking tape, but not combined yet.

But his videos are very cool, and I'm looking forwards to more. I didn't
realize he was that young.

~~~
petra
>> nobody is working on cheap masking

There's maskless lithography, which is cheap, as far as those things go:
[https://en.wikipedia.org/wiki/Maskless_lithography](https://en.wikipedia.org/wiki/Maskless_lithography)

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abecedarius
Caltech had a freshman course like this in the mid-80s, using a homebrew low-
tech process. The dire warnings about hydrofluoric acid have stuck with me
ever since. It was fun to try to lay out your gate to take as little area as
possible -- fun you can revisit at [http://www.zachtronics.com/kohctpyktop-
engineer-of-the-peopl...](http://www.zachtronics.com/kohctpyktop-engineer-of-
the-people/)

I was 17 at the time too, but doing it on your own is something else.

~~~
kurthr
APh9 -a great class. Of course you can still buy HF chrome cleaner in a spray
bottle! [https://hpd.nlm.nih.gov/cgi-
bin/household/brands?tbl=brands&...](https://hpd.nlm.nih.gov/cgi-
bin/household/brands?tbl=brands&id=22001046)

It doesn't look as strong as the 2% solution PepBoys used to sell, though.

~~~
s0rce
I think some rust removers also contain HF.

~~~
zzazzdsa
Yep, Whink brand rust remover is 4% HF. It's a somewhat useful source of
hydrofluoric acid in a pinch. I recall a procedure for making uranium
tetrafluoride from uranium trioxide (which in turn was extracted from uranium
ore) using that brand of rust remover as the acidic fluoride source.

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joshumax
This is the guy who gave me the incentive to buy a SEM off of govt. surplus
for my lab.

Very nice to see that the ieee is finally writing about his PCB fab setup!

~~~
VectorLock
Where'd you get the SEM from?

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userbinator
I guessed correctly that he was inspired by Jeri Ellsworth, and that the
article would mention her too. Great to see he went beyond what she did, and
although trying to clone a whole 4004 might seem far-off, it's really a matter
of replication once smaller structures can be made.

Furthermore, Intel actually released the mask set for the 4004 many years ago:
[http://www.4004.com/mcs4-masks-schematics-
sim.html](http://www.4004.com/mcs4-masks-schematics-sim.html)

Another relatively "simple" early microprocessor that might be doable is a
6502, it also has the (reverse-engineered) mask layers available:
[http://visual6502.org/images/6502/index.html](http://visual6502.org/images/6502/index.html)

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djaychela
I wonder if he could make something like the totally unobtainable Curtis
filter chips, or other devices which are long out of production but still
desirable? I'd think there would be a business in there if it is doable at a
sane price. Obviously I have no idea how complex the internals of such a chip
are - is an 'analogue' chip significantly different internally to the CPU
talked about in the article?

~~~
blackguardx
In general, analog chips are easier to fab because less transistors are
involved and thus minimum feature size isn't as important. Typical parts have
merely a handful of transistors.

Cutting-edge analog ICs are a different beast, though. Tightly controlled
processes are the norm and post-fab trimming is common.

~~~
vvanders
I've always heard that analog is harder because you need to characterize the
full behavior of the transistor as opposed to just setup and hold times for
digital.

Then again I only tinker with discrete components so it's an area that's
somewhat foreign to me.

~~~
blackguardx
It all depends on what you are trying to do. Some good analog parts use a
BiCMOS process with both BJTs and FETs, which is exotic and complicated. The
margins of any process are usually complicated, though. Just look at how many
billions it takes to develop a cutting edge digital process.

In my opninion it would be easier to do interesting analog parts in a home lab
than an interesting digital part. Making an opamp would be easier than a
processor and more interesting than an XOR gate (around same # of
transistors). Also, you can do some analog stuff with only NMOS or PMOS, which
simplifies things by at least 50% compared to CMOS.

For a home lab, you care about process and characterization, but variation
isn't as much of a concern because you won't be making that many. Also, just
look at the development of the semiconductor industry. Early factories (making
analog parts) didn't look that much different from what you could cobble
together in a garage. By the time they were doing integrated processors,
things were a lot more high-tech.

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Mountain_Skies
Wasn't surprised to see it was one of Jeri Ellsworth's videos that inspired
him. The production quality of her videos seem stuck in the early 90s but the
actual content is top notch inspiration. She has a great one on the importance
of failure that anyone struggling with not being perfect could benefit from.
Nice to see younger folks getting value from her sharing.

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drallison
I have worried for years that budding electronics folks don't get an
opportunity to tinker any more, now that everything is integrated. Apparently
I need not have worried.... Godspeed to this new generation.

------
deepnotderp
Super cool!

He should work with a lab like SNF/ANFF to make more advanced devices, you
should be able to get access to one of the Raith E-beam machines for an
acceptable price.

~~~
msds
E-beam litho is...uh...not cheap. The system in the shared fab I use (WNF)
costs around $450/hr with various discounts applied. Also, you're not going to
get much done in just an hour. Now, maskless laser lithography is reasonably
cheap...

However, you can get reasonable quality masks for $150ish, and if you don't
care about wafer yield, you can fit all of the layers on one mask. It's 1970s
tech - 1:1 contact exposure, but you can hit a few microns.

~~~
deepnotderp
Fair enough, I guess we have different ideas of what cheap is, $4500 for a
small prototype is fair enough for me (especially considering there's no other
way to get ~50nm lithographic resolution), but on the other I run a funded
company, so I suppose the story is different.

------
jacquesm
Very cool. There's one way to make sure that you're not getting any free
'riders' on your Silicon though it will be quite a while by the looks of it
before he'll be able to make a CPU that can do useful work outside of small
embedded projects by todays standards.

Wonder how he deals with the various solvents required as well, Silicon wafer
production is notoriously dirty.

~~~
mozumder
Phosphene gas to dope P-type Silicon is also extremely deadly. People have
died changing empty tanks of Phosphene gas.

~~~
yohann305
links please

~~~
jacquesm
[https://www.google.com/search?q=phosphene+gas+msds](https://www.google.com/search?q=phosphene+gas+msds)

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otakucode
I have really wanted to do this myself. Buy some older fab equipment, and
produce NAND chips. Start selling 4TB SSDs for $100 or so. It's ridiculous how
long the price-fixing in the SSD industry has been permitted to persist, and
someone needs to take them out. We don't need even 10nm production for SSDs or
anything. Go ahead and fill a standard 3.5" drive cage with the device. Since
the chips function mostly in-parallel, you get speed increases just from
concurrent use. And I'd imagine you might find a subversive company willing to
sell you controller logic on the cheap. Just so absurd that such a basic part
as NAND chips can even get treated like a premium item despite being in
basically every product of any kind created in the past 10 years. Any other
component like that is commoditized and dirt cheap, especially when they
contain no rare materials.

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rossdavidh
This. Is. Awesome. Also, horribly frightening, if you've ever worked in old
fabs, they had some extraordinarily toxic stuff. My brain is torn in two
trying to figure out if I should cheer or shriek in fright. It reminds me of
the story of the kid who made a nuclear reactor.

~~~
downrightmike
Here's the guy:
[https://en.wikipedia.org/wiki/David_Hahn](https://en.wikipedia.org/wiki/David_Hahn)
His smug shot looks like he's been too close to the reactor. Looks worse than
deadpool.

~~~
jakenberg
Years of radiation exposure and the poor guy dies of alcohol poisoning.
'Murica.

~~~
mysterypie
> dies of alcohol poisoning

Cause of death was fentanyl. Earlier comment:
[https://news.ycombinator.com/item?id=15470983](https://news.ycombinator.com/item?id=15470983)

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forkandwait
Does anyone have a single, basic book recommendation that would describe chip
fab all in one place?

Also, it seems to me he or people like him should try to make microcontrollers
rather than "full" computer chips. I would buy something to drive blinky
lights for $5.00 that ran 1/5 as fast as an Atmel chip to support a free
chipmaking movement, but I can't see doing something for a general purpose
computer chip (with the same ratios at least).

~~~
fuzzfactor
If you take a look at the circuitry on some recent cheap multi-mode blinky
lights you can find a likely analog IC fabricated right there on the surface
of the small PCB and covered with a drop of epoxy, along with a few discrete
components and battery holder.

I found a more advanced digital application where the memory modules on our
automatic titrator's exchangeable burets are fabricated on about a 5x20mm
ceramic substrate and covered with the epoxy droplet with only the gold-plated
connector pads showing. Only a limited byte capacity is needed, enough to
contain the serial number and a line of variable text to store a couple user
variables.

Small feature size and physical chips off of a multi-IC silicon wafer are not
exactly essential for such a simple application.

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lerie82
My high school didnt even offer drivers ed, couldnt have a football team
because of drive-by shootings, shop class wasnt an option after my freshman
year (or metal shop) because of a fight that occurred, there were no
opportunities for this when I was coming up.

This is something high schools need to be investing in, literally this is what
is fueling our future, I think it's amazing, good job.

~~~
s0rce
I'm going to disagree. It is really interesting but I think the amount of
equipment, space and potentially dangerous chemicals (requiring extensive
supervision for high schoolers) and the associated PPE and proper
infrastructure to work safely aren't the best use of money/space for a high
school. Old equipment also requires a lot of maintenance to keep running. You
can learn about these things from a book, watching a plasma etcher or CVD
furnace run isn't exactly very exciting after all. Might be worth doing a few
of the simple processes but you need so much equipment to do the whole
process. The lithography approach mentioned is interesting and could be cool
in an undergrad/high school setting.

~~~
wrycoder
Right. A shared fab run is better: many designs are merged on one wafer, and
the resulting chips are packaged and returned to the designers. The cost is
split, each designer gets only a few chips per run. Right now, the turn-around
time is lengthy, but, like PCB fab these days, that could change.

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yohann305
props to him and his parents for supporting this. Hope this story will inspire
other kids. Personally i'm inspired, adding this to my "bucket list" of
satisfying things to do when i will have time (someday...i hope...)

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antoniotorres
Interesting, how open are IC designs? And what software do they use create
complex circuits?

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CarVac
I met him at the New York Maker Faire. Pretty awesome stuff he's doing!

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finance-geek
Dont end up like this unfortunate boy:
[https://en.wikipedia.org/wiki/Ahmed_Mohamed_clock_incident](https://en.wikipedia.org/wiki/Ahmed_Mohamed_clock_incident)

~~~
Danihan
You mean the kid who disassembled a clock radio, intentionally made it look
like a bomb in a suitcase, used it as a distractant in multiple classes,
eventually got appropraitely disciplined for it, but then got tons of free
stuff, scholarships from universities, free money and swag, and personally
invited to White House by the President?

Yeah, heaven forbid anyone be treated that poorly.

~~~
whatshisface
Woah, I've never heard the story told like _that_. Could you link me to an
article or something? If true that's pretty depressing, I've seen a lot of
kids randomly blessed by corporate PR teams that want to look like they're
supporting education but I thought at least that story was true. (It's not
hard to make a clock and electronics in public places have caused a silly bomb
scare before...)

~~~
Danihan
It's mostly explained that way on the Wikipedia article, if you read between
the lines a bit.

His sister was also suspended from school for a bomb threat, so it seems to be
a sort of recurring pattern with his family.

