More info on homemade raw sources and processes:
How to make a CPU – a simple picture-based explanation
101–110 of 176 posts
Re: How to make a CPU – a simple picture-based explanation
#102Earlier quoted context omitted.
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?
RISC-V probably has the most "serious" effort of anything other than ARM and X86.
That's a fair estimate, but let's not forget IBM's Power architecture.
Re: How to make a CPU – a simple picture-based explanation
#103Earlier quoted context omitted.
> anti-intellectual backlash of the early 2000s I've never heard of this. Could you elaborate, please?
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.
Eh, Futurama was close, too.
Re: How to make a CPU – a simple picture-based explanation
#104Earlier quoted context omitted.
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?
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 th…
I think it probably depends on what "produced" means here.
If it means designs inside an EDA environment, design get submitted and shows up realized, then that is possible now. And it's not all that expensive. eFabless chip ignite is quoting ~$10K for 100 QFNs in 130nm. That's getting into beater car territory. https://efabless.com/chipignite/2110C
If it means actually fabricate then I think there is no way because a DIY won't have the scale to compete on price and they won't be able to bring any custom processing step to justify being at boutique scale. Think about PCBs. We used to make them ourselves with chemical etch. Now I don't even use breadboards because a custom bare fab is $5 and the components cost more than that. I also get a much better electrical result, and it doesn't fall apart if I look at it funny.
The main problem with ASICs is the amount of skill/time that it takes to do it right. Floor planning, track planning, closing timing, etc. etc. on an ASIC is much harder than an FPGA. You don't even have to do half those things on an FPGA.
With an FPGA one can almost get compile and go if you're willing to be loose on area and performance. ASIC CAD tooling is no where near that at the moment. Closed or open source.
Re: How to make a CPU – a simple picture-based explanation
#105Circuit 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.
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 c…
If I remember correctly, the silicon used to manufacture transistor-grade wafers is purified to roughly 10 impurities for every billion silicon atoms. Less pure starting stock might increase the cost of getting there, but probably not by too much.
Re: How to make a CPU – a simple picture-based explanation
#106Earlier quoted context omitted.
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?
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 fe…
> 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.
7nm logic mask set costs are estimated at $10.5M. Of course you could always use a slightly less leading-edge node and save a lot of money.
Slide 13:
https://semiwiki.com/wp-content/uploads/2020/03/Lithovision-...
Re: How to make a CPU – a simple picture-based explanation
#107Earlier quoted context omitted.
Well, this chap managed to make his own chips at home: http://sam.zeloof.xyz/category/semiconductor/ Plus an electron microscope!
He used wafers with premade structures on it.
So he "only" did metal deposition to make the interconnects? I haven't read the story, but I was thinking that there's no way you would handle some of the toxic chemicals used for doping.
Re: How to make a CPU – a simple picture-based explanation
#108Earlier quoted context omitted.
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?
It's possible. The chemicals are not too dangerous, and yes, you can train yourself. Maybe it wouldn't fly in the EU.
> Maybe it wouldn't fly in the EU.
May I ask why?
Re: How to make a CPU – a simple picture-based explanation
#109Earlier quoted context omitted.
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.
Yeah, I don't think people will be pulling pure silicon crystals at home any time soon.
If they do, I imagine they’d leave it at that instead of going on to make a chip.
Re: How to make a CPU – a simple picture-based explanation
#110It'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…
Any university graduate-level fabrication lab class has the equipment to do this. A self-aligned, metal-gate process is relatively simple. You can probably build something akin to a 6502 in it. The main issue is creating the masks. I'm not sure where you would get rubylith and the associated machinery for contact printing in this day and age. As a side note: the thing stopping commodity VLSI is the CAD tools , not th…
I don’t know if $60k sounds cheap to you, but I’d hardly call it a commodity.