Of Roach Killer and Rust Remover: Sam Zeloof’s Garage-Made Chips

A normal life in hacking, if there is such a thing, seems to follow a predictable trajectory, at least in terms of the physical space it occupies. We generally start small, working on a few simple projects on the kitchen table, or if we start young enough, perhaps on a desk in our childhood bedroom. Time passes, our skills increase, and with them the need for space. Soon we’re claiming an unused room or a corner of the basement. Skills build on skills, gear accumulates, and before you know it, the garage is no longer a place for cars but a place for pushing back the darkness of our own ignorance and expanding our horizons into parts unknown.

It appears that Sam Zeloof’s annexation of the family garage occurred fairly early in life, and to a level that’s hard to comprehend. Sam seems to have caught the hacking bug early, and by the time high school rolled around, he was building out a remarkably well-equipped semiconductor fabrication lab at home. Sam has been posting his progress regularly on his own blog and on Twitter, and he dropped by the 2018 Superconference to give everyone a lesson on semiconductor physics and how he became the first hobbyist to produce an integrated circuit using lithographic processes.

Sam didn’t go into the genesis of his interest in DIY ICs, but it’s clear from a brief shop tour on his YouTube channel that it only came about in the last few years. In 2016, the shop seemed to contain none of the equipment that Sam would need to make his dream come true – the high-vacuum chamber, the turbomolecular pump, the tube furnace, the chemistry lab, and the optical and electron microscopes. Sam rattles off this gear in his talk like it was no big deal to obtain, and indeed tells us he scored most of it off eBay for a song. It doesn’t hurt that the family home is near Princeton; college dumpsters make for the best diving.

Relatively easy though the equipment may have been to come by, knowing what to do with it was another matter. The first part of Sam’s talk, a review of the physics of semiconductors, assures us that he has given himself the education needed to put the tools to work. Sam’s first semiconductors, simple PN junction diodes and photovoltaics, came along pretty early in the process. His first MOSFETs were born in early 2017, about the time that his homebrew fab lab caught our attention.

Compared to what he had in mind, though, these early successes were just a warm-up act. Sam wanted to make an IC using the same photolithographic techniques used by commercial chip fabs. He had to learn how to handle the silicon wafers, heat treat them to create an oxide layer, pattern them using a DLP projector of his own devising, learn to apply dopants sourced from roach killer and weighed with a homebrew microgram balance made from a panel meter movement, and pull a vacuum nearly equal to that of outer space in order to harness thousands of amps to deposit thin metal films. The end result: the “Z1” chip, a PMOS dual differential amplifier. Sam said the fabrication process took about 12 hours total, and while he didn’t have a wire bonder to mount it to a lead frame at the time, the chip was tested and it worked.

After we ran the original piece on Sam, his mother Beth Deene contacted me to say thanks. She related that at the time, Sam was struggling with his high school’s administration, who refused to approve an independent study that would have given him more time to pursue his project. She lamented that they “couldn’t see the value in what he’s attempting to do.” It’s hard to believe in this day of STEM programs that any educator could be that ignorant; indeed, even a minimally gifted administrator would have been shouting Sam’s accomplishments from the rooftops as an example of what great things the district’s students were capable of. The mind boggles.

Regardless of the hurdles, or perhaps because of them, Sam pressed on. He started at Carnegie-Mellon this fall, and while he now has access to their $100 million fab lab, he’ll probably miss the garage where it all started.

27 thoughts on “Of Roach Killer and Rust Remover: Sam Zeloof’s Garage-Made Chips

  1. Me. I think this is like building a nuclear reactor in your Garage.

    Great job Sam.
    And as for the high school’s administration, they should get there heads out of the sand.
    Putting it nicely.

  2. He’ll probably come out of uni thinking the same thing about the professors. Education is not for making anyone intelligent, only to expose the mind to information.
    Anyone wanting to become intelligent has only to get their hands dirty and fail miserably until satisfied!

    1. Don’t bag on his professors until you’ve met them!

      But your basic point about active participation is spot on. When I was a freshman, a couple of us wanted to debunk the “penny from Empire State building” myth, and went to a prof to ask. He went to the chalkboard and we first started working through the ideal case, but then he said it probably wouldn’t work anyway b/c of turbulence and tumbling.

      We then designed some penny spinners to try to keep the coin vertical as it fell — for minimum wind resistance. Took the design back to the prof, and he helped us improve them a bit more, and got us access to the roof of the physics building where we timed a bunch of different pennies falling, trying to estimate the time at the halfway point and the ground.

      It wasn’t even close! Pennies get to terminal velocity, despite our best efforts, well within the fall from a 10-story building.

      But that’s not the point. The point is that we went to a prof with a fun question. Because he was a great teacher, he took time out to help. Some students aren’t self-directed, and some profs won’t give them the time of day. But when it all clicks, it’s awesome.

      Sam will find his way. :)

      1. Yeah, I don’t mean to bag the individuals (entirely). I had one of those fun and approachable professors, maybe even a few of them. My school was highly project based, and I was very engaged. Uni was good enough that I hope to do it some more in the future.
        All those projects, while enthusiastically genius in their own right, are ultimately dead in the water soon as next term or year rolls around. Most of the real world changing innovation is spawned in a garage, the military, or a big corporation’s research lab.

  3. High school administrators are generally not geeks. I nearly failed to get independent study credit for a prototype wearable computer in high school because the administrators didn’t see why anyone would ever want to carry a computer on their person at all times and what good all that tinkering could possibly do. Luckily my shop teacher was a geek and signed off on it after the administrators wouldn’t. Ultimately, though, even if your high school never gets it other geeks will and hiring managers at most tech companies are geeks, as are some of the admissions folks at schools with good engineering and applied science programs.

    Even that is nothing to the joy of taking something that was once mysterious and figuring it out. That is what really makes most of us tick and having followed along with Sam’s progress through Hackaday it seems pretty clear that even if none of us were cheering him on and vicariously enjoying the thrill of discovery and learning from the knowledge he shares as he goes he’d have toiled away in the garage for the sheer fun of it. That’s what makes geeks odd and wonderful.

  4. Well done, Sam. Great presentation, and I agree with the excellent advice you give at the end: always, always pursue knowledge and experience. Even if you fail a few times, you will learn.

    1. Thanks, Eric, but my husband and I are no more skilled at parenting than anyone else…we let both of our sons pursue whatever their interests are and support wherever that takes them. We’re very proud of both of our boys and it’s been very rewarding to watch them follow their dreams.
      Best regards, Beth and Haskel

      1. For what it’s worth, your husband is named after a programming language. And I think you describe the right thing to do with a smart kid, support him and let him explore. Some parents can be a letdown for a smart kid. Still, Sam deserves most of the praise for doing stuff plenty of 40 year olds couldn’t make work! Kilby and Noyce are famous for achieving less than Sam’s done, although they were 60 years earlier. Still, nobody does home microchip fabbing, far as I know. Maybe half a dozen people in the world.

    2. Thanks, Eric, but we are not any more skilled at parenting than anyone else…we let both of our sons pursue their interests and support wherever that takes them. We’re very proud of both of them and it has been very rewarding watching them follow their dreams.
      Best regards,
      Beth and Haskel

  5. Sort of puts a bit hope back into you when considering this younger generation. Far too often we see vulger and violent mask wearing youths causing all kinds of hateful uncivil trouble and then we see this guy doing fantastic things. There really is hope. :-)

      1. To save both you and me some time, I’m talking about mobs like ANTIFA and their lawless thuggery. The rise of many “great” dictators is often fueled by such rabble dominating the streets, drowning out dissent or anything that gets in their way. These kids need to get jobs and go hungry when they refuse to work, or at least be denied any iPhone upgrades. They are so detached from reality I don’t know if they are salvageable. I sure hope they can be set straight, but once bent up badly and with lots of drugs readily available things look rather bleak for them. …no guidance at home as children…no guidance at day-care…no guidance at school or university…it’s no wonder they are such lost NPC sheeple. It’s really sad and DANGEROUS if there are enough of them.

  6. Well done, Sam!

    You should put this on your resume (no, you’re not too young to have one) and start looking for an internship with one of the semiconductor companies. Try Analog Devices…

  7. How did the big tech giants start out? In the garage…the best board room / lab environment for all. Look at HP, Apple…heck even ENCOM (TRON reference)…all started out in a garage.

  8. Actually… thinking about it with realistic timelines in mind…. we indeed should be up to the time by now, for sure…, where the hobbyist has an avenue by which they can design and make or order their own chips just the same as back in the day we could design and order or make our own boards.

    Have fun with what you can do, not trying to discourage… just trying to tell you to watch out for those that are.

    1. There is an unsatisfied niche in the 20-2000-transistor range, believe it or not. PALs and other PLDs or gate arrays devices are nice but have some real limitations. Also, I have yet to see a realistic way to get reproductions of say, old game console IC’s. The more important consideration is that garage people try things the military and corporations would just never even think of or rather, dismiss outright.

      I looked into not just the old lithographic silicon wafer solutions, but printing circuit traces for ‘medium-customizability’ microscopic-scale boards. A literal printed circuit board would be nice way to do some things. Not sure you’d want to go past the complexity of a 555, though. ;)

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