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A home-made lithographically-fabricated integrated circuit

sam.zeloof.xyz

101–110 of 122 posts

Re: A home-made lithographically-fabricated integrated circuit

#102
post #75

Earlier quoted context omitted.

Citation needed? The inorganic materials used in semiconductor fabrication, especially in the early days, tend to be fairly benign and are used only in small quantities relative to other industry. The HF monster everyone is talking about in this thread is dangerous only as a concentrated acid. It's highly soluble -- reduce it with a rainstorm or two and let it recombine to a neutral pH and you rapidly get to (literal…

“We were putting into industrial production a lot of really nasty chemicals. There was just no knowledge of these things, and we were pouring stuff down into the city sewer system.” - Gordon Moore https://www.bloomberg.com/news/features/2017-06-15/american-... (cites the main source that is no longer on the web) https://www.youtube.com/watch?v=hrtyUnad7Jo (audio from the interview) Despite the quote, what a lot of pe…

We know a lot more now than we did.

There’s a generation or two of chemists, pharmacists, etc who habitually mouth pipetted common lab solvents that we now know to be carcinogenic.

As early as 1969 chemists were identified as having increased cancer risk

https://pubs.acs.org/doi/abs/10.1021/cen-v047n008.p014b

Re: A home-made lithographically-fabricated integrated circuit

#103
post #99

Earlier quoted context omitted.

Thinking a little more outside the box, you might look into using germanium instead of silicon. I don't know much about the germanium system, except that it supposedly grows less oxide. You're still going to have to deposit and remove oxide somehow, though, which means CVD reactors and silane. It's not going to be easy to get away from explosive toxic gases and dirty processes.

Not to mention DiBorane and Arsene... 1000C anneal cycles, teratogenic photoresist ethers, UHV equipment, and muti-kW RF sources. It's possible to demonstrate um scale MOS with a small lab, but not safely in anything resembling a normal garage. Hoping to replicate a multi-$B process at home is a fool's errand.

While we're at it, a modern scanner costs many million dollars, weighs tons, and sits on its own separate foundation on pilings that go down to bedrock so that it doesn't pick up vibrations from the air handling systems. DIY it ain't :)

Re: A home-made lithographically-fabricated integrated circuit

#105
post #44
post #42

Earlier quoted context omitted.

The fundamentals of a transistor, sure, but where does computer engineering include the chemistry of the actual lithography processes?

I suspect knowing the fundamentals gets you pretty far, just knowing that UV and masks are a way to do it is enough for people to re-create the tech given the resources. Maybe e-beam would be a easier start? IDK. Not related but fun given the q: https://news.stanford.edu/news/2015/june/computer-water-drop...

>I suspect knowing the fundamentals gets you pretty far,

Not much further than eighties, and you are not getting anything done with seventies era ICs.

I'd say. After seventies, most of academic research gets almost wholly separate from the fab floor, and of course fab owners and equipment makers keep to their valuable secrets.

At TSMC, the EUV workgroup, for example, is a very select cohort of people with 10+ years at the company, with posted security bonds, screened for loyalty, and signed an omerta style NDA.

Re: A home-made lithographically-fabricated integrated circuit

#107
post #99

Earlier quoted context omitted.

Not to mention DiBorane and Arsene... 1000C anneal cycles, teratogenic photoresist ethers, UHV equipment, and muti-kW RF sources. It's possible to demonstrate um scale MOS with a small lab, but not safely in anything resembling a normal garage. Hoping to replicate a multi-$B process at home is a fool's errand.

While we're at it, a modern scanner costs many million dollars, weighs tons, and sits on its own separate foundation on pilings that go down to bedrock so that it doesn't pick up vibrations from the air handling systems. DIY it ain't :)

what is a scanner in this context? what is its role?

or is this a stepper? or scanning electron microscope?

Re: A home-made lithographically-fabricated integrated circuit

#108

Earlier quoted context omitted.

While we're at it, a modern scanner costs many million dollars, weighs tons, and sits on its own separate foundation on pilings that go down to bedrock so that it doesn't pick up vibrations from the air handling systems. DIY it ain't :)

what is a scanner in this context? what is its role? or is this a stepper? or scanning electron microscope?

A scanner is a photolithography tool like a stepper, except instead of exposing the entire shot at once, it sweeps (scans) a narrow rectangular exposure across the shot, and then steps to the next one. This allows for lighter, more precise optics. Confusingly, there's a piece of standard office equipment with the same name. Even more confusingly, Canon makes both kinds! Be sure you call the right technician for service.

Re: A home-made lithographically-fabricated integrated circuit

#110
post #71
post #33

Earlier quoted context omitted.

Nice HF technical overview: https://ehs.unc.edu/files/2015/09/hydrofluoricacid.pdf (tldr; nope; read it.) I needed to dissolve(ha!) fluorite once. You can get it started by adding a few drops of conc H2SO4 to your beautiful aqua regia solution. It goes deeper red, some happy bubbles appear, and as long as it stays put, makes it's own "aqua nasty"(pg88) as you gently add your powdered sample. I thought AQR+SA was call…

> Rectal administration has caused acute colitis with perforation. disturbing that we know this

Not really. Rectal administration of drugs is one of the fastest ways to administer a drug outside of IV.

Unfortunately, I found out about it because of a now-deceased friend who succumbed to alcoholism. Near the end, he would drink rectally, since his esophagus was effectively destroyed. Also, since there's no gag reflex to keep you safe, this way is one of the easiest ways to kill yourself with alcohol.

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