[HN Gopher] Second IC
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Second IC
Author : parsecs
Score : 365 points
Date : 2021-08-13 23:45 UTC (23 hours ago)
(HTM) web link (sam.zeloof.xyz)
(TXT) w3m dump (sam.zeloof.xyz)
| intricatedetail wrote:
| This bothers me that these days average engineer can't afford to
| buy or rent reasonable sized space to do experiments like this.
| My dream is to build my own IC but I am sure doing that in my
| living room would likely turn it into something uninhabitable.
| I've been looking at renting some space in an industrial zone,
| but that's out of reach money wise even in a remote area.
| dang wrote:
| Related threads:
|
| _Homemade IC (2018)_ -
| https://news.ycombinator.com/item?id=21239145 - Oct 2019 (40
| comments)
|
| _Home Chip Fab_ - https://news.ycombinator.com/item?id=20657398
| - Aug 2019 (131 comments)
|
| _A home-made lithographically-fabricated integrated circuit_ -
| https://news.ycombinator.com/item?id=16955549 - April 2018 (116
| comments)
| kken wrote:
| It's a pretty clever process as some of the more critical steps
| (gate oxide, poly deposition) are done elsewhere. This allows for
| very stable transistors without a lot of Vth shift. I also like
| his use of resits for the ILD.
|
| Maybe it would be possible to replace some of the more agreessive
| acids used for poly and Al etch with KOH and lowly concentrated
| HF.
|
| Also, one could also use alloy doping with aluminium to create
| the junctions and skip the need for a high temperature diffusion.
| But that would probably not result in a 10um process and present
| yield issues...
| mrfusion wrote:
| It would be so cool if microprocessors went the Linux route and
| the best in class were created from open source projects.
|
| Well one can dream.
| grishka wrote:
| Isn't that what FPGAs are good for?
| Filligree wrote:
| FPGAs are nowhere near as fast as the equivalent ASIC, not to
| mention the toolchains are an utter disaster. There's a very
| narrow window in which they're useful, which certainly
| doesn't include anything meant to be best in class.
| amelius wrote:
| It's time for some big software companies like Google to
| commoditize their complement. So who knows ...
| vitiral wrote:
| This is such amazing stuff!
| dtgriscom wrote:
| Related thread: https://news.ycombinator.com/item?id=28179241
| marktangotango wrote:
| Really cool stuff, I was wondering if anyone was doing diy
| photolithography.
| [deleted]
| actually_a_dog wrote:
| > Now we know that it's possible to make really good transistors
| with impure chemicals, no cleanroom, and homemade equipment.
|
| The good news here is that 2 of those 3 issues are pretty easily
| solvable. With some work, and a ton of HEPA air purifier
| machines, you could probably turn an area the size of a small
| shed or 1 car garage into a class 10000 cleanrom pretty easily.
| It would be simplest if this area were embedded in a larger area,
| like a 2 car garage, but, you could probably squeeze it into just
| a plain old 1 car garage.
|
| Chemicals, you can buy online from scientific supply houses.
| Some, like acetone, you can buy from less specialized sources in
| high purity. Water and alcohol, you can either buy at high purity
| pretty easily, or buy lower grade stuff and purify it.
|
| Of course, at the point where you're going for higher purity
| stuff like this, you might want to switch from acetone as a
| solvent to DMSO. DMSO itself is safe to handle and doesn't
| evaporate like acetone will.
|
| > Silane
|
| Yeah, nasty stuff. Toxic as hell, ignites spontaneously when
| exposed to air. I used to work near a rather large storage tank
| that contained the stuff. Needless to say, I am glad there never
| was an accident. :-) Very wise to avoid this stuff.
|
| ---
|
| https://www.americancleanrooms.com/class-10000-clean-room/
|
| https://en.wikipedia.org/wiki/Dimethyl_sulfoxide
|
| https://en.wikipedia.org/wiki/Silane
| adrian_b wrote:
| His achievements are great, but the only reason why he could
| this without a cleanroom and with less pure chemicals is that
| he succeeded to find on eBay a batch of silicon wafers with the
| MOS gate oxide already grown on them.
|
| Growing the MOS gate oxide without extreme cleanness has no
| chance of succeeding.
|
| The difficulty of this process has caused a delay of many
| decades between the time when the MOS transistor was first
| imagined (in 1928 by Julius Edgar Lilienfeld, then also in 1935
| by Oskar Heil) and the time when working MOS transistors were
| made for the first time, around 1960.
| amelius wrote:
| Are these unfinished wafers commonly used/sold in the
| industry?
| baybal2 wrote:
| Want to stress how extreme cleanliness have to be. Free
| halogen ions from the air are enough to mess it up.
|
| That's why early fabs had very unusual placement
| requirements: not close to chicken farms, agriculture, water,
| or sewage treatment plants.
|
| Intel famously got seasonal yield losses which they traced to
| agricultural activities, and seasonal chicken coup cleaning.
| amelius wrote:
| How much m^3 do you need to grow these structures? Couldn't
| it be done in a very confined space?
| pottertheotter wrote:
| Are they able to clean the air well enough now that it's
| not an issue?
| eurasiantiger wrote:
| It's not really feasible to separate noble gases out of
| the atmosphere in a building HVAC system.
| gravypod wrote:
| Couldn't you just use positive pressure of O2 and
| nitrogen? Push all other gasses out? Would cost a lot but
| it is doable.
| baybal2 wrote:
| More recent tools do work that way. The whole "tool line"
| is flushed with process atmosphere.
| amelius wrote:
| Probably the buildings are so big nowadays that it's
| geometrically impossible to have farms nearby the actual
| plant.
| kragen wrote:
| A class 10000 clean _bench_ might be more practical. A lot
| easier to keep your cleanroom clean when the humans are outside
| of it, just sticking gloved arms in from time to time.
|
| Be careful about purifying alcohol. Some backward countries
| have religiously-based legal prohibitions on this. My own
| backward country tightly controls acetone as a "precursor" to
| "stupefacients".
|
| Nice thing about silane is that you don't have to worry about
| accidentally breathing it. There's a cheap and simple process
| for manufacturing it on demand from magnesium silicide, so you
| don't have to store it either.
| amelius wrote:
| > With some work, and a ton of HEPA air purifier machines, you
| could probably turn an area the size of a small shed or 1 car
| garage into a class 10000 cleanrom pretty easily.
|
| I wonder if it would be possible to automate the entire process
| with robotics and reduce the effective "clean" space even
| further.
|
| There was this post a while back about a company that used thin
| cassettes to keep the wafers clean when moving between process
| steps.
| s0rce wrote:
| Is DMSO really a replacement for acetone in most applications?
| ta988 wrote:
| In some applications. It is dangerous if it dissolves things
| because now they can get under your skin easily. The problem
| is that it is not easily removed (requires much more energy
| than acetone) and it oxidizes. It is also more viscous and
| freezes at pretty high temperature (around 20degC).
| etaioinshrdlu wrote:
| I want Sam to turn this into a startup somehow. There has got to
| be something better than the semiconductor industry we have
| today, which has ridiculous barriers to entry.
| chroem- wrote:
| It's not strictly semiconductor-related, but if there's one
| thing I would like to see, it's low cost, made-to-order
| integrated analog computers. The low power consumption of
| analog devices would offset the larger feature size, and
| hopefully the process could be made cheap/flexible enough so
| that needing a different IC design for each use case would be a
| non-issue.
| hobo_mark wrote:
| You can get your chip fabbed at the Skywater foundry for 10K
| (can't remember how many dies that buys you), the open source
| toolchain does support analog if you know what you are doing.
| 2muchcoffeeman wrote:
| I imagine this will end up like 3D printing though.
|
| A 3D printer is fantastic to prototype your own designs. Or to
| build custom parts in low volume.
|
| But it will never replace traditional manufacturing at scale.
| And even CAD is a massive barrier to entry.
|
| And 3D printing is far more useful for everyday things but we
| still haven't figured out a model to make the technology
| accessible to the general public.
|
| This is a very impressive project though. I'm envious.
| Robotbeat wrote:
| Well 3D printing is super great for fast, functional
| prototyping. So if that's all it is, it'd be great!
| ygjb wrote:
| But the model for it to be accessible to the general public
| is readily available, it's just not evenly distributed.
|
| I can go to several local fed-ex offices here in Vancouver
| and they will print on demand a file that I provide them, for
| a very reasonable cost (given that they eat the cost of
| misprints and supervision of the process).
|
| There are a number of fairly successful print on demand
| businesses that are niche specialized as well, heroforge is a
| great example.
| redis_mlc wrote:
| > fed-ex offices
|
| Kinko's. FTFY. :)
| robinsoh wrote:
| > There has got to be something better than the semiconductor
| industry we have today, which has ridiculous barriers to entry.
|
| I am curious about your exact meaning. When you say barriers to
| entry, it sounds like you're implying the "semiconductior
| industry we have today" is actively putting up barriers to
| prevent you from entering? Is that what you are trying to say?
| If so, please elaborate so that we can understand what these
| barriers you are facing are.
|
| Or is it just that you're acknowledging that it actually costs
| many billions to build up a commercially viable fab?
| robinsoh wrote:
| I notice no response and yet downvotes. Parent claims there
| are "ridiculous barriers to entry" implying patent thickets
| by the "semiconductor industry we have today" or something
| along those lines. I can't help but notice no further
| explanation was provided to substantiate parent's claims.
| politician wrote:
| We have that problem of trusting our compilers, and the guys
| that are trying to build a completely clean bootstrap of gcc
| (?). The ability to manufacture some known-safe hardware might
| help that project.
| tverbeure wrote:
| Turning old processes into a startup is what Melexis did 30+
| years ago: they acquired obsolete fabs in Eastern(?) Europe and
| repurposed them to make sensors, which don't need state of the
| art processes.
|
| The 180nm open source eFabless shuttle runs that are sponsored
| by Google are done by X-fab, which is owned by Melexis' founder
| as well.
|
| I don't see how this garage stuff (impressive as it is!) can be
| turned into a startup. It's not as if there is some kind of
| breakthrough here?
| jdboyd wrote:
| I wonder if it could support specialty audio chip
| manufacturing.
| exDM69 wrote:
| A company called Alfa in Latvia does this, they use
| outdated semiconductor fabs (probably from Soviet union
| era) to make reproductions of vintage synth chips from the
| 80s, CEM33xx etc.
| eurasiantiger wrote:
| Exit via Cirrus Logic.
| [deleted]
| parsecs wrote:
| I was thinking about something like that too. How hard would it
| be to have a semiconductor-manufacturing-as-a-service with
| lower inertia like those PCB manufacturing services? The
| hobbyist affordable board houses these days generally have
| extremely good processes and quality that even beat some
| "industrial" board houses, as they're thoroughly refined by
| fabricating hobbyist boards with sometimes really awful DFM
| considerations
| baybal2 wrote:
| Masks are expensive
| cibyr wrote:
| Which is probably why Sam's process uses a DLP projector
| install of masks.
| s0rce wrote:
| A mask at this scale would just be a few hundred dollars I
| think (chrome on glass)?
| baybal2 wrote:
| The cheapest Taiwanese mask shops who work for discrete
| device manufacturers will bill you 10x at least.
| colechristensen wrote:
| You have to find the capability / price point sweet spot and
| you could probably create a big market, that kind of thing
| has been happening more and more lately... but it takes a lot
| of domain knowledge and luck.
|
| A good example of this is how Arduino broke open the hobbyist
| electronics market which went from circuit programmers and
| prototype boards that would run in hundreds of dollars on the
| low end to $20 or something to get in at the ground level.
| 0xcde4c3db wrote:
| There are companies working on scaling e-beam lithography,
| which might be along the lines you're looking for [1] [2]
|
| [1] https://en.wikipedia.org/wiki/Electron-beam_lithography
|
| [2] http://www.multibeamcorp.com/
| hobo_mark wrote:
| Given the relative affordability of Skywater's service
| nowadays, I imagine we will eventually see custom silicon
| projects on Kickstarter and the like.
| taway21812 wrote:
| Does anyone have a rough sense what the cost of Sam's equipment
| is, and how someone can emulate this on a budget with second hand
| purchases?
|
| Also roughly, would anyone know the cost per batch of chips? I'd
| love to run thing as a learning exercise for middle or high
| school students and wonder how costly it would be.
| exDM69 wrote:
| His lab would cost a fortune if you were buying the equipment
| new from the manufacturer. But he has been able to source a lot
| of decommissioned semiconductor fab equipment through eBay and
| donations etc. Like his wire bonding machine. He has spent
| years of effort setting it all up, so it's not something for a
| one off project.
|
| But replicating his simpler transistor experiments should be
| doable on a smaller budget. Also check out Jeri Ellsworth's DIY
| transistor project. Some nasty chemicals and special equipment
| is necessary but nothing too much for a hobbyist.
| redis_mlc wrote:
| I think you're grossly underestimating the difficulty and
| patience needed to make ICs. Better just to show a film.
|
| A more reasonable hands-on school project would be using
| EasyEDA or KiCad and making a PCB using either a low-end CNC
| machine or chemical processing.
|
| (I had shop class in high school using lathes, etc. and
| chemistry class with actual reagents, but just from a risk
| standpoint that's mostly unthinkable today. Both can kill a
| student.)
| tverbeure wrote:
| I don't know the minimum amount equipment needed to make these
| chips, but his garage is stuffed with old but still expensive
| equipment (if you need to buy it on eBay.) Things like a wire
| bonder, an electron microscope, a vacuum chamber etc.
|
| I think that most of these were donated to him though.
| hhh wrote:
| Sam is one of my favorite content creators, all his stuff is
| amazing.
| monocasa wrote:
| Would love to know the ancillary stuff like waste disposal.
| Playing with this stuff without making a new superfund site is
| arguably just as difficult as the core work.
| perihelions wrote:
| The "HF" doesn't stand for "high five!"?
| jwbwater wrote:
| HF is no big deal, haven't you watched breaking bad? Piece of
| cake, just use plastic containers. What could go wrong?
| s0rce wrote:
| Its actually easy to dispose of, just neutralize with
| calcium carbonate (forms safe insoluble calcium fluoride)
| and dispose of down the drain or in the trash. Just don't
| get it in on your skin in the process. There are other
| options to neutralize as well.
| ncmncm wrote:
| I was surprised to find that 1% dilute HF is both adequate to
| purpose, and safe to handle.
| xnormal wrote:
| Low concentration HF is frequently uses in artistic glass
| etching. With reasonable precautions it's not more
| dangerous than cleaning your drain with caustic soda. Just
| don't be stupid.
| ncmncm wrote:
| What matters is that if you splash some on your hand, you
| have time to rinse it off before the flesh melts off your
| bones.
| kragen wrote:
| Safe is relative. _I 'm_ such a genius that I managed to
| injure myself doing a reaction with a single reagent,
| namely, making amorphous plastic sulfur. I accidentally
| caught the sulfur on fire, you see. If you ever find
| yourself in this situation, resist the temptation to try to
| blow it out; you will regret inhaling near a sulfur fire.
| akanet wrote:
| I recently visited the Berkeley Nanolab. As I recall, the main
| waste products are either acids that are neutralized before
| being returned to the city sewer system, or exotic gases that
| are vented in dilute enough quantities to be safe.
| monocasa wrote:
| To be clear, my comment isn't a callout; I unironically
| believe that it's explicitly being addressed. I'd just find a
| writeup around the subject interesting.
| tingletech wrote:
| the campus runs its own sewer since 1867. Feeds into East Bay
| MUD.
| parsecs wrote:
| I believe Sam avoids using anything that's super awful to deal
| with. There's well defined procedures for taking care of most
| chemicals that involve neutralizing them sufficiently to be
| flushed down the drain
| monocasa wrote:
| Even the specifics there of what subset of materials gets you
| to making chips without disposal issues would be super
| interesting to me. It's a complex space to navigate, and
| shrouded a bit in mystery and trade secrets.
| lashloch wrote:
| "Especially my amazing parents, who not only support and
| encourage me in any way they can but also give me a space to work
| in and put up with the electricity costs... Thank you!"
| mikewarot wrote:
| He's to the point now where he could make a small ASIC, or CPU,
| or maybe a high power FET (by paralleling a lot of them)
|
| I wish him all the best of luck.
| pyb wrote:
| Very cool and impressive.
|
| Here is another person who had a fab at home at some point :
| http://www.microfab.co.uk
|
| They were building not microchips but STJ sensors.
| lmilcin wrote:
| I wonder how far it would be possible to go with an open source /
| open hardware to have open process for IC development and
| production.
|
| What I mean is given relatively old process but new tooling and
| software, could we expect to make usable system that is
| completely transparent from security point of view? And resistant
| to future attempts at preventing people from having access to
| trustworthy hardware?
| showerst wrote:
| I'm thinking about trying to take this on myself, after
| watching and reading everything from Sam and Huygens Optics,
| and going through Chris Mack's course online.
|
| I think the problems for offering any kind of hardware solution
| for this is that everything involved is either "pretty easy" or
| "pretty darn hard".
|
| A decent UV laser, a workable optics bench, and 3/4 of the
| process chemicals are cheap and readily available. You can even
| build a "clean enough" fume hood. The processes are decently
| documented already in an open way.
|
| Super high precision 3x axis closed loop micrometer or piezo
| stages, a wire bonder, and good quality pre-layered wafers are
| so far beyond small distributor or hobbyist scale that they're
| relegated to elusive Ebay scores. The other 1/4 of the process
| chemicals require getting a big distributor like Sigma to work
| with you, and some of them really require chemistry training to
| work with safely, although it's great to see some of the
| workarounds. I believe Jeroen at Huygens Optics is a chemist by
| training. He's comfortable working with things like HF that you
| really don't want to promote to amateurs, but are essential to
| get past a few thousand transistors.
|
| Getting a complete process beyond the 70s era stuff at an
| amateur level is probably impossible right now. The absolutely
| insane requirements for silicon growing/cleaning alone are just
| more than one person can fit in their head, or their garage.
|
| I'd compare it to large liquid fueled rocket engines, which are
| another common nerd dream project. Plenty of people understand
| the principles, and a few college teams or the equivalent have
| built working ones, but there's probably just too much to know
| and understand to do it solo and with no serious budget.
| bob1029 wrote:
| This is all going to depend on exactly how much $$$ you have to
| spend. The major step-wise jumps in cost can usually be
| attributed to higher resolution photo techniques and the
| precision tools required.
|
| Most of the other processes can theoretically be carried out at
| garage-scale, as the precision is more about chemistry than
| dimension or scale.
| lmilcin wrote:
| People buy 3d printers. I'm sure there would be people
| interested in building their own silicon chips, even if it
| would be a lot more involved.
|
| I can imagine a little niche market for tools and services
| for that kind of production. I design electronics but I order
| my PCBs from jlcpcb because I can get much better product
| with much less hassle.
| jbverschoor wrote:
| Super cool. These kind of things are needed to keep things from
| being perceived as being "impossible"
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