[HN Gopher] How to make a CPU - a simple picture-based explanation
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How to make a CPU - a simple picture-based explanation
Author : robertelder
Score : 333 points
Date : 2021-11-10 15:10 UTC (7 hours ago)
(HTM) web link (blog.robertelder.org)
(TXT) w3m dump (blog.robertelder.org)
| calebm wrote:
| Looks like magic
| wrycoder wrote:
| Maxwell and Lord Kelvin would have no idea what it was all
| about.
| GhettoComputers wrote:
| The article doesn't correspond to reality.
|
| >3) Now you have 98% concentrated silicon dioxide. Purify it to
| 99.9% pure silicon dioxide.
|
| >4) Purify it further to 99.9999999% polysilicon metal.
|
| >While cutting-edge nanometer scale features are not likely to be
| accessible for a hobbyist, micron-scale amateur chip fabrication
| does appear to be quite feasible. I have not tried this myself,
| but Sam Zeloof has, and you should definitely check out his
| YouTube channel. I think you could probably even build some basic
| chips with far less equipment than he has if you get the optics
| right. You could probably make it a hobby business selling cusom
| chips to other tech people!
|
| >A Word Of Caution: In case it wasn't already clear, I don't
| advise that anyone actually attempt making integrated circuits in
| their apartment in the manner shown in this video. The
| 'photoresist' and 'developer solution' in this video is just a
| colored prop. The real chemicals are usually hazardous and you
| should only work with them with proper safety gear in a well
| ventilated area or in a fume hood.
|
| Its outdated and in reality you would go to Shenzhen or use a
| custom fab to make custom designed chips with raw materials
| sourced from special exotic materials that only make sense for
| scaled operation.
|
| I highlighted the steps 3 and 4 because its not how its done at
| all. High grade silicon is obtained in a pure state and doped for
| the chips rather than obtaining random types and refining them.
|
| Its not even easy compared to homemade nuclear reactors, which
| need a lot of natural sources of uranium to enrich but can be
| done, the refinement is more related to older germanium chips.
| nereye wrote:
| Somewhat related, it does not seem too expensive (~$100 per
| chip, minimum *50) to get an ASIC done (purely from a fab
| perspective and ignoring the large elephant in the room of
| coming up with a design in the first place), e.g. see
| https://www.zerotoasiccourse.com/ (no affiliation).
|
| As for the design, one way is to re-use existing IP and join it
| together, e.g. see https://efabless.com/ etc.
| wrycoder wrote:
| He's explaining, as crudely as possible, what's going on in the
| semiconductor industry as a whole. Even Shenzen and TSMC are
| only small parts of it.
|
| High purity polysilicon is still produced by zone refining.
| GhettoComputers wrote:
| Yes it is refined and doped, my point is that he leaves out
| the sourcing of essential materials that you don't refine but
| must get that is already pure, it has to be purer than any
| random silicon its like saying just get any sand that people
| will assume comes from beaches for construction when its
| essential that they are not worn or have rounded edges,
| except this is so specialized that it must come from one mine
| in the world. The limit was well understood in Soviet Russia
| with their inability to source the raw materials of
| comparable purity to produce microchips, even if the design
| was the same, the USSR was not able to produce them without
| what is considered essential to chips of good quality. https:
| //www.sciencedirect.com/science/article/abs/pii/S00652...
|
| Even today China cannot match the quality of American chips
| and relies on US raw materials from Spruce Pine for
| manufacturing chips. It isn't optional, its like saying you
| can make a 1:1 steak with nothing but beef bones or chicken.
| https://ashvegas.com/bbc-report-spruce-pines-high-quality-
| qu...
|
| >This ultra-pure mineral is _essential_ for building most of
| the world's silicon chips - without which you wouldn't be
| reading this article.
| wrycoder wrote:
| The BBC article is referring to high purity quartz, not
| silicon. It is used to make a quartz crucible - a large cup
| - of that high purity quartz. It's essential that the
| crucible not contaminate the polysilicon.
|
| (A note in passing: the semi industry doesn't use hyperpure
| silicon. They use a lesser grade and add epitaxial layers.)
|
| The crucible can stand the high temperature of molten
| silicon. The purified polycrystalline silicon is melted in
| the crucible. Then a single crystal 'seed' is dipped in the
| molten silicon and slowly withdrawn, while rotating. That's
| how you make a high purity single crystal silicon ingot.
|
| Before it's zone refined, the poly is synthesized by
| reducing high purity silane gas (SiH4), which was in turn
| produced from quartz sand.
|
| It would be interesting to know if the industry is still
| using natural quartz crucibles - the latest wafer size is
| now 450 mm - nearly 18 inches. Maybe someone else here can
| comment whether the traditional pulling process will be
| used at 450 mm.
| cwoolfe wrote:
| After all that hard work, sell it at a few cents per chip.
| kayson wrote:
| Circuit designer here - feel free to ask any questions about the
| manufacturing process, design etc.
|
| Having a thorough understanding of the process, I thought this
| was hilarious. But if you really want to understand the process,
| it's pretty terrible. It spends 10 steps on making a wafer, and
| then the bulk of the actual process is condensed to 16.
| 7373737373 wrote:
| Do you think chips in the 10k-100k transistor range will some
| day be able to be produced by hobbyists? Or are the chemicals
| simply too dangerous and machines too expensive to be
| affordable at that scale?
| kayson wrote:
| No, I don't think so. But it's not because of the chemicals
| or machines. There's not really any demand for it. Most
| hobbyist "ICs" are fully digital and can already be realized
| on an FPGA. For simpler applications, you can probably
| program a microcontroller to do what you want.
|
| Integrated circuits are appealing to industry because they're
| integrated - they can be smaller and they reduce cost (long
| term; still need the upfront investment). These are important
| things for many products, especially in RF, but they aren't
| really driving factors for hobbyists.
|
| That being said, people are trying!
| http://sam.zeloof.xyz/second-ic/
| 7373737373 wrote:
| Yeah, I saw and am amazed by his work, which made me wonder
| whether chip manufacturing could get as streamlined,
| compact and mainstream as 3d printing is today!
| R0b0t1 wrote:
| It's possible. The chemicals are not too dangerous, and yes,
| you can train yourself. Maybe it wouldn't fly in the EU.
| bullen wrote:
| Have you ever used https://www.fossi-foundation.org?
|
| If I had the skills I would immediately investigate how to
| couple a RISC-V CPU with some open GPU on that platform!
| kayson wrote:
| With most open source hardware efforts, like this, it's not
| really so much circuit design as it is just code. All of the
| open source efforts I've seen revolve around digital
| circuits, which are written in some kind of RTL and turned
| into an actual circuit by completely automatic processes.
| It's still great, and I fully support them, but there's a
| massive amount of non-digital that's crucial to getting these
| systems up and running. Not to mention that even if you have
| an open source CPU RTL, for example, you'll need access to a
| closed-source and often NDA-blocked PDK (process development
| kit), fabrication company, etc. I remember seeing some
| efforts at open sourcing the PDK part as well, but remember
| being unimpressed.
| gautamcgoel wrote:
| Suppose I want to make a custom ASIC with 20B transistors. I
| have a lot of money to spend but no semiconductor experience.
| How do I go about hiring good chip designers? How much $ should
| I realistically expect to spend on design, verification, and
| fabrication, respectively? I've heard $20M is the ballpark for
| a mask on a leading edge node. What is the marginal cost per
| CPU?
| kayson wrote:
| That sounds way too high for mask costs. You're definitely
| looking at 7 figures, but I don't think they've yet hit 8.
| Unfortunately the answer to all of your budget questions is:
| it depends. It's going to scale with the complexity of your
| requirements. Something like a custom ARM chip with heavily
| custom machine learning and signal processing, high speed
| clocking, etc, would probably need a decent sized team and a
| few years. On the other hand, there are tiny teams in Asia
| that crank out bitcoin mining ASICs like candy.
|
| I'm going to guess at a number and say you're probably
| looking at $10-20MM all in.
|
| As far as hiring good designers, you really need the relevant
| technical background to screen them. Assuming you need a
| team, I would suggest starting with someone in a director
| position at a large company with experience in your area of
| interest. They would be able to more concretely define the
| project and determine human resource requirements/allocation.
|
| If your ASIC is just large but not complex (meaning lots of
| repeated structures), and you can get away with just a few
| strong designers, I would suggest hiring a consultant to help
| you define the project and screen candidates. EE profs at
| your local university might be a good start.
|
| Feel free to shoot me an email (in my profile) if you want to
| describe your project in more depth and I'd be happy to offer
| what advice I can.
| freedomben wrote:
| Not what you were offering so feel free to ignore this, but I'm
| super curious about RISC-V. Do you know if any serious attempts
| are happening to make RISC-V based systems? And if not, do you
| know why? Is it too raw/un-polished?
| kayson wrote:
| Not my area sorry!
| mhh__ wrote:
| RISC-V probably has the most "serious" effort of anything
| other than ARM and X86.
| lordnacho wrote:
| What's the canonical book? I used to know this from my EE days,
| but it's been too long.
| kayson wrote:
| For circuit design or manufacturing?
|
| I haven't been in school for a while, so I'm not sure what's
| current. I really liked Baker's book - CMOS circuit design.
| It had a decent overview of the manufacturing process for the
| perspective of a designer, as well as good introductions to
| major design topics.
|
| Unfortunately, with modern processes, most of the textbook
| design equations and learning no longer apply so it becomes
| as much learning an art as it is science.
| lordnacho wrote:
| Both. Ah I think I might have had that book until my
| parents' basement flooded.
|
| Yeah of course when it comes to how things are actually
| done it's hard to know without actually working in the
| field. But I just wanted an overview.
| kayson wrote:
| I think the Baker book is good for an overview. I also
| used Pierret's Semiconductor Device Fundamentals in
| undergrad. It goes more in depth for device physics than
| it is a pure manufacturing text, but I recall it also had
| a nice overview.
| ic_dummy wrote:
| How are the pn junctions created? The article says I can
| "optionally" dope the wafers. Why is that optional? Are they
| doped to create both p and n areas, or just one type? Or are
| multiple wafers used? Or are areas somehow doped after etching?
| Thank you for entertaining my dumb software person questions.
| kayson wrote:
| This is one area the article did a very poor job of
| explaining. In some processes, you treat the entire wafer
| before you get started with the rest of the procedure. One
| example that does this is SOI (silicon on insulator)
| processes. Others may not need this "global" doping, and from
| what I know most bulk silicon cmos processes do not do this.
|
| Then you do the lithography (photoresist developing, etching,
| etc) to expose specific regions on the silicon that you want
| to dope to create devices like transistors, for example. So
| first you might expose all of the p-type transistor (PMOS)
| diffusion areas and dope them. Then you'd remove all the
| photoresist, repeat the procedure to expose n-type diffusions
| and dope that. And so on for the various needs of that
| particular wafer.
|
| PN junctions are created simply by having p-type doped
| silicon adjacent to n-type doped silicon. The boundary
| between the two is the PN junction. In practice what I
| usually see is a square of one type with a ring around it of
| the other, but these devices are not frequently used.
| GhettoComputers wrote:
| Can you talk about if the US has microchip supremacy due to raw
| materials from Spuce Pine's pure silicon, and if there are any
| sources that are almost as good or being used instead? Is it
| almost like De Beer's diamond monopoly?
|
| Do you use any countries or specific factories that do better
| refinement or are the raw materials directly shipped to the
| manufacturing country? What do you make from the wafers
| usually? Are certain sizes much harder to make? I know for
| example that larger sensor for digital cameras are much harder
| to make. I also heard of redundant circuits used to increase
| the yields of chips, how often is this used and when is it most
| useful versus less?
| robbiep wrote:
| I'd never heard of Spruce Pine, interesting. I wasn't able to
| read the wired article but another article said it wasn't the
| silica/silicon that's the world-beater there though, it's the
| quartz for use in crucibles etc?
|
| Also - does the US _really_ have microchip supremacy? The
| highest tech fabs are non-us (Samsung and TSMC)
| [deleted]
| kayson wrote:
| The US may have technological supremacy when it comes to
| design and the resultant products, but it lags behind in
| terms of actually manufacturing semiconductors. The dominant
| players are in Asia (TSMC, Samsung, GF) and Europe (GF).
| Intel has their own fabs, but they are currently behind the
| competition, and up until very recently only fabricated their
| own products. There are a lot of other companies in the
| industry with fabs, but they're generally making their own
| products - discrete devices - rather than integrated
| circuits/System-on-a-Chip's.
|
| Another issue is the equipment used for manufacturing. It's
| very hard to come by, and the classic example is ASML
| (Netherlands), which dominates the market for lithography
| equipment.
|
| I work on the design side, not in a fab, so I can't tell you
| much about sourcing or refining the silicon for wafers.
| Wafers are used to make every single microchip you can
| imagine. There has been a slow but continuous push towards
| using larger wafers, since its more cost-effective. I imagine
| it's more difficult, but couldn't tell you any specifics.
|
| As far as manufacturing each individual integrated circuit:
| yes, larger is harder to manufacture because there is more
| physical space for a defect to occur. There are some design
| challenges as well when you get very large, but it's not a
| significant overhead because you're usually doing your design
| in sub-pieces anyways.
|
| Some designs do use redundancy, as you mentioned. This is
| more often the case for very large, very uniform structures,
| like DRAM, flash, CPU cache, etc. But there's a tradeoff
| because you waste money on that redundancy for every chip
| that comes out with no defects. And there's overhead to
| actually testing the part in order to utilize the redundancy.
| In my experience, yields are targeted at the high 90%s these
| days, so the redundancy would have to be very cheap to be
| worth it. For almost all RF, analog, and mixed-signal
| circuits, there is no redundancy. I'd say most digital
| circuits, except the largest, also don't have any.
| gorgoiler wrote:
| It's really really fun doing this in software. You should try it.
|
| Fetch decode execute cycle. Registers. Memory. An instruction
| set. An assembler. And plug it all into an emulator to watch your
| factorial(n) at work!
|
| Here's one someone else made earlier:
|
| https://www.peterhigginson.co.uk/AQA/
|
| It's rubbish. So is yours, but you've got to build it first
| before you can brag.
| showerst wrote:
| If you're into this, Huygens Optics has an awesome series where
| he builds a wafer stepper at home. His is a little less advanced
| than Sam Zeloofs but the videos are way better --
| https://www.youtube.com/watch?v=_w0Z2Y5vaAQ
| capableweb wrote:
| I recall there being a game mentioned somewhere here on HN, where
| you start with basic logic gates (I think), and you build up a
| fundamental CPU at the end of the game, using the parts you
| discovered along the way.
|
| Problem is, I don't remember what the game is called, and no
| amount of searching seems to help me. Anyone know what it was
| called?
| shhsshs wrote:
| - Turing Complete (2-dimensional circuit building, mission-
| based):
| https://store.steampowered.com/app/1444480/Turing_Complete/
|
| - NandGame (2-dimensional circuit building, mission-based):
| https://nandgame.com/
|
| - Logic World (3-dimensional circuit building, no
| missions/goals yet):
| https://store.steampowered.com/app/1054340/Logic_World/
| krallja wrote:
| NandGame? https://nandgame.com/
| GhettoComputers wrote:
| Not the same game but if you like that genre zachtronics is
| really good at logic games and has assembly programming.
| https://zachtronics.com/tis-100/
|
| >Print and explore the TIS-100 manual, which details the inner-
| workings of the TIS-100 while evoking the aesthetics of a
| vintage computer manual!
|
| >Solve more than 20 puzzles, competing against your friends and
| the world to minimize your cycle, instruction, and node counts.
|
| >Design your own challenges in the TIS-100's 3 sandboxes,
| including a "visual console" that lets you create your own
| games within the game!
|
| >Uncover the mysteries of the TIS-100... who created it, and
| for what purpose?
|
| https://zachtronics.com/shenzhen-io/
|
| >Build circuits using a variety of components from different
| manufacturers, like microcontrollers, memory, and logic gates.
| Write code in a compact and powerful assembly language where
| every instruction can be conditionally executed.
|
| >Read the included manual, which includes over 30 pages of
| original datasheets, reference guides, and technical diagrams.
|
| >Get to know the colorful cast of characters at your new
| employer, located in the electronics capital of the world.
|
| >Get creative! Build your own games and devices in the sandbox.
| Engineering is hard! Take a break and play a brand-new twist on
| solitaire.
|
| I didn't know an assembly game could be made, it's a pretty
| hard game only progammers and very logical people would enjoy.
| jtolmar wrote:
| Silicon Zeroes [1] starts out slightly more abstracted than
| what you described (byte-level operators, register files, ALUs,
| that sort of thing) and builds up to a full CPU.
|
| [1] https://pleasingfungus.itch.io/silicon-zeroes
| mbil wrote:
| perhaps this https://news.ycombinator.com/item?id=28735441
| capableweb wrote:
| Yes, that was exactly it! "Turing Complete" it's called
| apparently, available at Steam:
| https://store.steampowered.com/app/1444480/Turing_Complete/
|
| Thanks
| mkirsche wrote:
| That pixel based logic simulator, I made some years ago, might
| also entertain you:
|
| https://github.com/martinkirsche/wired-logic
| hoppyhoppy2 wrote:
| Not a game, but https://www.nand2tetris.org/ is a similar
| concept.
| mataug wrote:
| So if I somehow time travelled to ~1800 there's no way I'm making
| my own modern computer ?!
|
| Jokes aside, its fascinating to see how complex computers are
| under the many layers of abstraction that we've built on top of
| them.
| wrycoder wrote:
| You can start with figuring out how to make good insulated wire
| and then try to invent the generator and the transformer.
| jay754 wrote:
| This is absolutely gold. Very informative and hilarious pics.
| Cxckers wrote:
| As a film photography enthusiast, I love the parallels between
| making a chip and film development. I wonder if film developing
| was the original inspiration
| dfox wrote:
| Direct ancestor probably is mask-and-tape PCB design process,
| where the optical step also serve to shrink the (hand made)
| mask to significantly smaller size of the final board. In fact
| silicon masks were for a long time designed using essentially
| same process.
|
| In fact if you want to make something mostly flat with small
| features some variation of photo etching process tends to be
| the easiest and most repeatable way to go about that.
| hedgehog wrote:
| Photo etching is used for all kinds of things including making
| plates for printing, I'd guess that's the more direct ancestor.
| hedgehog wrote:
| Nice illustrations, though step 16 is pretty much "Draw the rest
| of the F** owl."
| azalemeth wrote:
| I'm pretty sure producing the monocrystalline ingot with seven
| 9's purity also counts as the "rest of the owl", along with
| basically every other step in this guide. I'm not even
| convinced that the sawing step is simple - thermal stresses,
| limitations, impurities, tool hardness and dimensional accuracy
| concerns, minimising material losses, etc. (I loved his butter
| knife).
| jkingsbery wrote:
| The knife was a great touch! It did look like he was lining
| it up carefully...
|
| Also, it took me two passes through to notice the tooth brush
| in step 16.
| hedgehog wrote:
| Yeah fair. Pretty much every part of the process is bonkers.
| Just the light sources draw something like 1 megawatt and
| weigh over 100 tons (for extreme ultraviolet). EUV gets
| absorbed by everything including air, which is bad, but the
| light source requires plasma so somehow you need both the
| plasma and vacuum in the same machine without a window or
| whatever to separate them. Then the features on the chip are
| so small that random variance in the spatial distribution of
| landing photons causes defects. And that's just the light,
| it's amazing anyone can make the process work at all.
| pitspotter2 wrote:
| The hilarity illustrates an important point. We never just make a
| thing. A recipe or blueprint is a convenient fiction. Rather we
| participate in a dynamic evolving process which itself evolved
| through many cycles of copying, repetition and debugging. Even
| the first version wasn't strictly original because the idea was
| borrowed from elsewhere. 'Oh you work at the olive press. How
| would you like a job with this new-fangled printing machine?' And
| so on back to the initial and highly controversial creation of
| the Universe.
| AlanSE wrote:
| You might not do great to start with computers, and instead, do
| better to start from the dawn of civilization.
|
| https://www.howtoinventeverything.com/
|
| What I got from this is that I could make homemade coal by
| myself, MAYBE. I don't know if there's any climate on Earth
| where I could eek out a net energy return on primitive crops.
| If there was no one telling me what to do, I would surely
| starve in early agricultural times. But hey, that's what the
| Pharaoh's for, amirite?
|
| Basic bronze tools are a mind-numbing mess to mentally process.
| 7373737373 wrote:
| You might like this video "I tried blacksmithing and only got
| slightly burned": https://www.youtube.com/watch?v=e2HUg144liM
|
| https://bootstrapping.miraheze.org/wiki/Main_Page also feels
| relevant
| timthorn wrote:
| Take a look at the Toaster Project if you want to see building
| an item from scratch carried through all the way:
| http://thetoasterproject.org/
| tnorthcutt wrote:
| Mentioned a couple other times in this thread but I don't think
| anyone has linked Sam Zeloof's video of essentially doing this:
| https://www.youtube.com/watch?v=IS5ycm7VfXg
|
| It's fantastic and I highly recommend watching it.
| marcodiego wrote:
| For a real case of someone making integrated circuits at home,
| this boy did it: http://sam.zeloof.xyz/ for real.
| spideymans wrote:
| Anyone else stuck at step 3? :)
| nynx wrote:
| It'd be really awesome if microprocessors, even at a low-end
| process node like 130 nm, could be made with room-sized machines
| or smaller. There's a lot of space for companies wanted to
| manufacture their own MCUs, for instance, without relying on
| massive supply chains.
|
| I think this'll happen at some point, as silicon manufacturing
| hits final roadblocks and becomes increasingly commoditized, but
| it'd be nice if it were sooner rather than later.
|
| (This would be nice for self-sufficient decentralized communities
| being able to produce their own microelectronics as well.)
| trollied wrote:
| Well, this chap managed to make his own chips at home:
| http://sam.zeloof.xyz/category/semiconductor/
|
| Plus an electron microscope!
| nynx wrote:
| Sam is super impressive, but to be fair he bought premade
| wafers and bought a used SEM.
| thesuitonym wrote:
| Did he do his own etching? I'd say buying blank wafers
| would be a perfectly reasonable place to start, but if
| you're buying printed wafers, then you might as well buy
| the whole chip.
| grenoire wrote:
| Yeah, I don't think people will be pulling pure silicon
| crystals at home any time soon.
| amelius wrote:
| He used wafers with premade structures on it.
| GhettoComputers wrote:
| The author misleads you with a point I brought up, it is not
| possible without globaliziation providing essential raw
| materials components that have no replacement unless that is
| your local environment. Spruce Pine has silicon that gives the
| US microchip supremacy that has dominated for the entire
| duration of manufacturing. It will never be commoditized that
| you can take off the shelf raw materials from anywhere locally
| and refine them. In the structure of globalism I linked to how
| google is allowing home designers to produce older technology
| chips.
|
| https://www.electronicsweekly.com/news/business/diy-chip-10k...
| https://www.hackster.io/news/efabless-google-and-skywater-ar...
|
| If you are interested in self-sufficient decentralized
| communities, microchips are not essential for a good society or
| long life. https://aeon.co/ideas/think-everyone-died-young-in-
| ancient-s... They're useful for being able to make non
| specialized hardware that can run general programs that many
| can support. Microchips do calculations and are more useful in
| scaling, analog computers can take some roles but it will be
| more wasteful to produce specialized hardware.
|
| I don't know if vaccuum tubes need globaliziaton to make but
| you are not going to make decentralized microchips with local
| goods, they are not fungible raw materials like food.
| nynx wrote:
| I don't think it's inherent that doped silicon will stay the
| dominant microelectronics substrate and I think it's
| plausible that people will find new ways to grow it that
| don't require excellent raw materials.
| adminscoffee wrote:
| yeah you are onto something. massive supply chains have a ton
| of carbon footprint. which some people that doesn't matter but
| for someone like myself, i am a bigger fan of less carbon
| emissions. i wonder if there is a way we can build an etching
| machine and print chips somehow, the process seems a little
| clearer after watching this simplified video. i think it can be
| done, everything complex is just a bunch of simple steps, solve
| each step and get closer to the goal. might be fun to create a
| github type community where people push their ideas to a source
| control platform where others can chime in and give their
| input. so like open source chip manufacturing, kinda like how
| 3d printers started out with makerbot and other open source
| printer projects.
|
| i think it can be done and it would be fun. we have to filter
| out people who have a vested interest in chip manufacturers
| because they may try to over complicate the process to protect
| their purse. so like a vouch system, where we know the people
| coming in have the right heart and won't purposely screw up
| moral
| XnoiVeX wrote:
| If you knew enough VHDL you can make your own digital chips
| including CPUs using off the shelf FPGAs...
|
| https://blog.classycode.com/implementing-a-cpu-in-vhdl-part-...
| nynx wrote:
| Yeah, certainly true, but FPGAs are beholden to the same
| supply chain. This doesn't fix the issue at all.
| Koshkin wrote:
| Here's how you make a vacuum tube:
|
| https://www.youtube.com/watch?v=EzyXMEpq4qw
| lsiunsuex wrote:
| I've always been curious how someone gets into this line of work.
| Is it all via college / post education and your directly
| recruited by these companies? Obviously, this is a very hard
| (impossible?) thing to teach yourself. I can't imagine more than
| a few universities offer this type of education? Where would you
| start / what path would you go down to be a chip designer / work
| for an Intel / AMD ???
| rubylark wrote:
| My brother and several of his friends do this for a living at
| Intel. Most of them have Electrical Engineering PhDs, though I
| believe one is a Chemical Engineer. My brother's thesis
| specifically was in 2d transistor design and worked under a
| Material Science professor. I believe most universities have
| professors who teach Semiconductors classes, whether it is
| under the name Computer Engineering, Electrical Engineering,
| Electronics Engineering, Chemical Engineering, or Material
| Science.
|
| It would be difficult to learn on your own as explained in the
| article: you need a lot of specialized equipment, a high class
| of clean room, and a lot of very dangerous chemicals. (My
| brother once described what the hydrofluoric acid he used semi-
| regularly does to person and completely horrified our parents).
|
| Downside of this field is that there are very few job
| opportunities without relocating. If you're in the US, you can
| work at Intel... or Intel. Unless you're willing to move to
| Taiwan and work at TSMC.
| spijdar wrote:
| Hydrofluoric acid and other "fluorinating" chemicals like
| chlorine trifluoride really are horrific. Most of my
| experience in chemistry is from a brief stint working as a
| student helper in an undergrad chemistry lab, and
| (thankfully) never encountered HF, but we were told many
| times just how dangerous it is.
|
| It's been a while, but I remember the biggest danger isn't
| the acidity itself, not even being a strong acid, but
| fluorine's tendency to "deep dive". It just sort of slowly
| eats into things and creates layers that are comparatively
| hard to remove. So if you spill hydrochloric acid or whatever
| on yourself, you wash it off, maybe get some severe tissue
| damage, but it's localized and washes off.
|
| On the other hand, the HF tends to stick around, and as a fun
| side-effect, the fluoride salts it creates are poisonous to
| the body. And HF is tame compared to some fluorine chemicals
| used in chip etching/production...
| sgarland wrote:
| There are other fabs in the US - Samsung, Global Foundries,
| NXP, and other smaller places.
| [deleted]
| showerst wrote:
| Asking how to work in chips is kind of like asking how to be an
| engineer -- there are a million sub-specialties so lots of
| paths.
|
| Generally the degrees are Electrical Engineering, with classes
| along the lines of https://ocw.mit.edu/courses/electrical-
| engineering-and-compu... (note that's from 2003, just an
| example)
|
| There's also a ton of physics, and chemical and industrial
| engineering in the process steps.
| irishloop wrote:
| At the public university engineering program I attended in
| 2000ish (UConn), we offered CompSci (mostly software focused),
| CompEng (mostly hardware focused), and CompSci+Eng (a balance
| of both). Either Eng program included several courses on
| hardware-level EE courses and circuit design, hardware
| engineering, etc.
|
| One of the guys I did my senior design project with ended up
| working with AMD on processor stuff, so there are educational
| opportunities, I think you just need to be more on the
| CompEng/EE side of things and make it your focus.
| [deleted]
| f00zz wrote:
| > this is a very hard (impossible?) thing to teach yourself
|
| It isn't! The book "Code" by Charles Petzold is a great
| introduction to digital electronics and computer architecture.
| There's also the "Nand to Tetris" course (which I didn't take
| but people here are always recommending). You can build a
| simple CPU in a digital circuit simulator. If you're feeling
| adventurous you can write it in Verilog and simulate it, and
| even get it to run on a FPGA. This is all stuff you can teach
| yourself.
|
| Of course this is not quite enough to make you a chip designer
| at AMD, but you'll know enough to get over the feeling that a
| microprocessor is an inscrutable artifact of alien technology
| brought from Alpha Centauri.
| wrycoder wrote:
| Nand2tetris, which is far more sophisticated than Code, would
| be a good background (highly recommended), but it has almost
| nothing to do with the technology actually used in a wafer
| fab.
|
| The relevant disciplines are physics (mostly condensed
| matter), inorganic chemistry, industrial engineering, and
| electronics.
|
| Find a school that teaches semiconductor engineering, take
| their courses through vlsi and ASICs.
|
| Then land a job at a fab and the rest is learn on the job
| training.
|
| It's like the difference between a PC board fab and an
| electronics design engineer, taken to the google power.
| thrashh wrote:
| ...electrical engineer?
| zoenolan wrote:
| This was about 20 years ago, things maybe different now.
|
| I got hired on the architecture side for GPU's after working a
| few years. My academic background was computer graphics with a
| focus on parallel algorithms and performance optimisation.
| After a couple of years working mostly on low level code, C/C++
| and assembly. I got a call from a recruiter.
|
| The semiconductor industry is larger than just Intel and AMD.
| Like any job, taking some time to look around the career pages
| should give you a good idea what skills they are interested in.
|
| https://www.nand2tetris.org/ is a nice introduction to the how
| processors are put together. Book wise Hennessy and Patterson's
| books, Computer Organization and Design and Computer
| Architecture: A Quantitative Approach are good for background.
| I never did much on the layout side but learning Verilog and/or
| VHDL would be helpful but not essential.
| 2143 wrote:
| > Where would you start / what path would you go down to be a
| chip designer / work for an Intel / AMD ???
|
| Perhaps by studying Electronics Engineering (also called
| Computer Engineering, which is different from Computer
| Science).
|
| At my university in USA, I remember recruiters from Intel
| setting up a stall or something to recruit students. It was in
| the building which mostly has computer science and computer
| engineering students, so I guess that's who they were looking
| for.
|
| This was less than 5 years ago.
| mattbillenstein wrote:
| I studied computer engineering (EE/CS) from 1996-2001. My
| senior year the college offered a minor in VLSI design, it was
| a 4 course series covering the very basics of semiconductor
| design and test and as one of the projects we actually paired
| up and designed a small chip, here's a photo of the finished
| die. Simple 2-layer metal 1 micron process - this is a serial
| multiplier for two sixteen-bit integers.
| https://vazor.com/drop/mulman.jpg
|
| Most of the students in these classes were graduate students,
| so with our normal course load as seniors in engineering, this
| was a tremendous effort. For a four-credit class I would
| sometimes have to work 20+ hours a week just on one class.
|
| But, it was a good stepping stone to get into the industry - my
| first job was at LSI Logic executing physical design, timing
| closure, etc for their customers. I learned a lot but
| eventually stepped away from it to focus on software and
| startups - I didn't want to die at that desk - the designs and
| teams were getting bigger and the design cycles longer. I did
| not relish the idea of working for 3 years on a single project.
|
| I do look back on it fondly though as it was closer to what I
| consider 'real' engineering - we did a ton of verification work
| and if you screwed up, it might be a million in mask costs and
| 3 months of time to fix. We did screw up from time to time and
| the customer often had some fixes, so on a new design, there
| were expected to be a couple iterations of prototypes before
| you went to production. I think the last design I taped out was
| in the 110nm node - ancient by today's standards.
| GhettoComputers wrote:
| Not trying to be rude, you need to be motivated enough to seek
| the answers yourself if its your truly important. If you want
| it badly you will find your answers. Here's a google sponsored
| inititive to help custom chip designers.
|
| https://www.hackster.io/news/efabless-google-and-skywater-ar...
| https://www.electronicsweekly.com/news/business/diy-chip-10k...
|
| Places like Shenzhen have a very good environment for this as
| well. https://www.youtube.com/watch?v=taZJblMAuko
| zackmorris wrote:
| I got my electrical and computer engineering (ECE) degree in
| 1999 from UIUC and learned everything but the very lowest-level
| chemistry, because I specialized in the VLSI (circuit design)
| side instead of fab. At that point, stuff like MIPS and the DEC
| Alpha were popular, and computers were just breaking the 1 GHz
| barrier.
|
| Unfortunately the dot bomb happened right after I graduated,
| and the anti-intellectual backlash of the early 2000s killed
| independent research during the outsourcing era, which never
| recovered.
|
| Sadly from my perspective, very little has changed in 20 years.
| Computers only reached about 3-4 GHz, and kept doubling down on
| single-threaded performance for so long that companies like
| Intel missed out on multicore. Only Apple with their M1 seems
| to have any will to venture outside of the status quo. The
| future is going to be 256+ symmetric cores with local memories
| that are virtualized to appear as a single coherent address
| space. But that could take another 20 years to get here.
|
| Meanwhile we're stuck with SIMD now instead of MIMD, so can't
| explore the interesting functional paradigms. Basically I see
| the world from a formal/academic standpoint, so I think in
| terms of stuff like functional programming, synchronous
| blocking communication, ray tracing, genetic algorithms, stuff
| like that. But the world went with imperative programming,
| nondetermistic async, rasterization, neural nets.. just really
| complicated and informal systems that are difficult to scale
| and personally I don't think much of. Like with software,
| honestly so much is wrong with the hardware world right now
| that it's ripe for disruption.
|
| Also hardware was a dying industry 20 years ago. We wanted
| fully programmable FPGAs to make our own processors, but they
| got mired in proprietary nonsense. There really isn't a
| solution right now. Maybe renting time at AWS blah.
|
| I feel a bit personally responsible for the lackluster
| innovation, because I wasn't there to help. I wasted it working
| a bunch of dead end jobs, trying to make rent like the rest of
| you. And writing text wall rants on forums that nobody will
| ever read anyway. So ya, don't be like me. Get involved, go
| work for a startup or a struggling company that has the
| resources to fix chips, and most importantly, have fun.
| kimixa wrote:
| >Only Apple with their M1 seems to have any will to venture
| outside of the status quo
|
| I find this an interesting opinion considering that the M1 is
| really just "The same, but a bit larger" - IE slightly higher
| performance at a higher cost.
|
| What exactly do you see with the M1 that makes it so
| different?
| colejohnson66 wrote:
| > Meanwhile we're stuck with SIMD now instead of MIMD...
|
| What about multi-core/multi-threading combined with massively
| out of order CPUs? Intel and AMD's chips have a dozen or so
| execution ports. So you can have your PADD running on one
| port, and a PMUL on another. It just happens all being the
| scenes.
|
| Intel tried a VLIW architecture with Itanium, but it was a
| flop for a variety of reasons. One of which was the lack of
| "sufficiently smart compilers". There's also the benefit to
| all the nuances of execution being in hardware: programs
| benefit from new CPUs without having to be recompiled. It has
| a much more intimate knowledge of how things are going than
| the software does (or even the compiler).
| pphysch wrote:
| This doesn't really answer the GP and reads like sour grapes
| from a "formal/academic" type who missed the boat on the last
| 2 decades of advances in computing and AI.
|
| > But the world went with imperative programming,
| nondetermistic async, rasterization, neural nets.. just
| really complicated and informal systems that are difficult to
| scale
|
| ...wat?
| rhapsodic wrote:
| _> anti-intellectual backlash of the early 2000s_
|
| I've never heard of this. Could you elaborate, please?
| bsedlm wrote:
| this is not an ellaboration, but a mere pointer based on
| one example: the sitcom Friends is sublty anti-intellectual
| and it came out around that time.
| carlhjerpe wrote:
| I'm born in 1994, I would also like to hear about this!
| aligray wrote:
| I found this absolutely hilarious and I'm not entirely sure why,
| just the tone of the instructions as if it's an ordinary thing to
| make in an afternoon. Brilliant.
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