131–140 of 176 posts
Not to oversimplify: first you have to flatten the rock and put lightning inside it.
Source: https://twitter.com/daisyowl/status/841802094361235456
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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.
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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…
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Sam is super impressive, but to be fair he bought premade wafers and bought a used SEM.
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.
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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.
Just because you, personally, aren't willing to spend the money doesn't mean something isn't a commodity.
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…
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…
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.
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?
To put it in perspective, a company a friend founded that is doing a very large but very regular ASIC for TSMC 10nm raised twice what you're ballparking and will end up doing another raise before tapeout. Chips nowadays are _expensive_ if you're anywhere near state of the art. The people who do very high performance chips are also very expensive.
But I'm also guessing that unless you're doing a bitcoin hashing chip, AI chip, or GPU, all of which is regular, your scale estimate is probably very off. If you're doing any of those, just don't.
That said, there are SOC vendors who do core plus, so it's possible that if this is just an accelerator, no matter how wide, you might be able to outsource the whole thing.
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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.
It’s much easier to produce silicon ingots than to do wafer fab, because of the currently tiny line widths.
But, it would make more sense to simply buy wafers (or epitaxial wafers).
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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.
Good dopant choices would be phosphorus oxychloride and oxidized boron nitride wafers.
As I recollect, he started with silicon wafers with an epitaxy layer. He then did the usual oxidations, diffusions, and metallization, along with all the photolithographic steps. No small feat!
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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.
They are not really that toxic. You do have to have a chemistry background and use a fume hood and a process sink with acid neutralization capability, like you find in many chem labs. Good dopant choices would be phosphorus oxychloride and oxidized boron nitride wafers. As I recollect, he started with silicon wafers with an epitaxy layer. He then did the usual oxidations, diffusions, and metallization, along with all…