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A High School Student Building Integrated Circuits

400 points| rbanffy | 8 years ago |spectrum.ieee.org | reply

55 comments

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[+] ChuckMcM|8 years ago|reply
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|8 years ago|reply
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.

[+] nraynaud|8 years ago|reply
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.

[+] abecedarius|8 years ago|reply
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...

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

[+] s0rce|8 years ago|reply
HF is dangerous and you definitely need proper PPE and calcium gluconate + a shower accessible but lots of us, myself included, work with it routinely.

warning: I'm not advising you go home and start etching silicon oxide and cleaning wafers with vats of HF without doing adequate research and preparation to do it safely.

[+] joshumax|8 years ago|reply
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!

[+] userbinator|8 years ago|reply
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

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

[+] djaychela|8 years ago|reply
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|8 years ago|reply
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.

[+] drallison|8 years ago|reply
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.
[+] Mountain_Skies|8 years ago|reply
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.
[+] deepnotderp|8 years ago|reply
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|8 years ago|reply
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.

[+] rossdavidh|8 years ago|reply
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.
[+] jacquesm|8 years ago|reply
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|8 years ago|reply
Phosphene gas to dope P-type Silicon is also extremely deadly. People have died changing empty tanks of Phosphene gas.
[+] otakucode|8 years ago|reply
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.
[+] forkandwait|8 years ago|reply
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|8 years ago|reply
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.

[+] lerie82|8 years ago|reply
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|8 years ago|reply
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.
[+] binarysaurus|8 years ago|reply
He did independently. Sure, there is a cost barrier but I don't the HS is one.
[+] yohann305|8 years ago|reply
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...)
[+] antoniotorres|8 years ago|reply
Interesting, how open are IC designs? And what software do they use create complex circuits?
[+] CarVac|8 years ago|reply
I met him at the New York Maker Faire. Pretty awesome stuff he's doing!
[+] finance-geek|8 years ago|reply
Dont end up like this unfortunate boy: https://en.wikipedia.org/wiki/Ahmed_Mohamed_clock_incident
[+] dang|8 years ago|reply
Please don't haul flamebait in here.
[+] Danihan|8 years ago|reply
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.