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Home Chip Fab

sam.zeloof.xyz

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Re: Home Chip Fab

#31

Post by esmi »

SkyPuncher wrote: post #22
hammock wrote: post #20

Please don't dump your solvent down the drain like every Silicon Valley fab did back in the day, poisoning the entire region for decades to come. Just look up how many EPA Superfund sites are in the South Bay due to trichloroethylene, TCE contamination. Dispose of it properly and safely.

> Dispose of it properly and safely. I see a lot of people say this, but I rarely see any actionable advice. How does your average residential person find and dispose of chemicals like this? Seems like most people end up pouring them down the drain simply because they don't know how to actually find a better means of disposing them.

Just google hazardous waste disposal and give it your location. My experience is in the US, and here many counties have something like this:

https://www.sccgov.org/sites/rwr/hhw/Pages/What-is-Household...

Re: Home Chip Fab

#32

Post by otakucode »

cr0sh wrote: post #18

This is all very interesting and amazing, and kudos to the person for being able to do this - but I think we need to take a step back here a bit; this doesn't look like something that "just anybody" could replicate. For one, this person seems to have some very advanced knowledge of some very advanced processes - I am not even sure where one would gain such knowledge from easily, though they do seem to have access to…

>but what foundation of knowledge they had prior to that point seem unknown?

Well, he hadn't graduated high school yet. Your points about the expense are probably sound, unless he was doing some serious wheeling and dealing (which is certainly possible, some high schoolers flip sports cars and make money that way, etc) but a large part of that would be an artifact of being one of the first to attempt this sort of thing at this scale. Modern manufacturing often doesn't scale down very well. Such steps are necessary, however, to improve the level of capability of the hobby community in general. The next project will probably be done cheaper, learning where there is flex in the process, etc.

Re: Home Chip Fab

#33

Post by basementcat »

hammock wrote: post #20

Please don't dump your solvent down the drain like every Silicon Valley fab did back in the day, poisoning the entire region for decades to come. Just look up how many EPA Superfund sites are in the South Bay due to trichloroethylene, TCE contamination. Dispose of it properly and safely.

> Please don't dump your solvent down the drain like every Silicon Valley fab did back in the day, poisoning the entire region for decades to come.

+1

Please develop a workable waste disposal strategy BEFORE thinking about cool disruptive home brew nanofab MEMS/circuit hacks.

Re: Home Chip Fab

#34

Post by mindcrime »

cr0sh wrote: post #18

This is all very interesting and amazing, and kudos to the person for being able to do this - but I think we need to take a step back here a bit; this doesn't look like something that "just anybody" could replicate. For one, this person seems to have some very advanced knowledge of some very advanced processes - I am not even sure where one would gain such knowledge from easily, though they do seem to have access to…

While your points are valid (or mostly so), I think you're being a little bit overly dismissive. OK, maybe not "just anybody" could do this, but about what can we say that "just anybody" can do it?

OTOH, considering a hypothetical group of dedicated enthusiasts who are willing to pool resources / funds / knowledge /etc. and work on something like this collectively, I'd just about be willing to wager than any moderately urban area in a "1st world" country has the raw potential to have a "garage chip fab" show up. Especially areas near one or more research universities and with a heavy tech presence (and therefore lots of technically adept people in the local population).

Of course not everybody will bother, because arguably there isn't much point other than education and a sense of self-satisfaction, given this bit: "Update 7/8/19: FET gate length (feature size) reduced to ".

Anyway, this seems like a pretty cool demo at worst, and "hats off" to Sam for pulling it off!

Re: Home Chip Fab

#35

Post by DC-3 »

bcaa7f3a8bbc wrote: post #14

And remember that the author Sam Zeloof was still studying in highschool when he completed this project.

He must have tolerant parents to allow experiments involving baths of HF and Piranha solution in their garage!

Seriously impressive though.

Re: Home Chip Fab

#36

Post by LargoLasskhyfv »

spectramax wrote: post #6

I was at Semicon Japan last year in December and I learn about the coolest semiconductor company (non profit research organization) ever - MinimalFab [1]. There isn't much information their website but this [2] video explains what MinimalFab is about. Essentially, it is a cleanroom-free, modularized fab where each process step in a fab is like a little ATM machine. Miniaturization of complex fab processes is mind blo…

That is very interesting! I watched that and found some more information after searching a little:

[1] https://www.yokogawa.com/yjp/solutions/solutions/minimal-fab...

It seems like this fab is a demonstrator, and is planned for sale. This makes me wonder if/when this will be available for maker style setups, at which process nodes & price per piece. Would be nice to be able to design some fully custom ip, have it tested, bonded and packaged, and optionally soldered, like you can have it with pcb services today.

One can dream, yes?

Re: Home Chip Fab

#37

Post by deepnotderp »

otakucode wrote: post #28

What happens to old fab tech? A few years ago I tried searching around online to see if there was anywhere you could buy decommissioned machinery for fabricating NAND flash, but I couldn't find anything or any sign that such things ever really come up for sale. Has anyone worked in a fab or otherwise have some idea of what happens to the stuff that worked at larger process sizes?

A lot of the stuff, e.g. 193i immersion litho, gets reused the by the fabs, other stuff gets used for older nodes, which are often still thriving, e.g. 180nm is popping for analog.

Re: Home Chip Fab

#38

Post by pjc50 »

bogomipz wrote: post #3

This is really fascinating. I apologize if this is a silly question but under the Fabrication section there is a pic titled "physical structure(Texas Instruments, 1997.)" My question is why do all of the components always look so "puffy" or "fuzzy" in these chip zoom-in pics? I guess I'm always surprised that such a precision process produces something with such imperfect looking shapes. Or are these slightly amorpho…

Necessarily it is operating at the limit of precision. If it wasn't blurry, you'd keep making it smaller until the blurring starts to become a problem again.

Re: Home Chip Fab

#39

Post by opencl »

SkyPuncher wrote: post #22
hammock wrote: post #20

Please don't dump your solvent down the drain like every Silicon Valley fab did back in the day, poisoning the entire region for decades to come. Just look up how many EPA Superfund sites are in the South Bay due to trichloroethylene, TCE contamination. Dispose of it properly and safely.

> Dispose of it properly and safely. I see a lot of people say this, but I rarely see any actionable advice. How does your average residential person find and dispose of chemicals like this? Seems like most people end up pouring them down the drain simply because they don't know how to actually find a better means of disposing them.

Your average residential person doesn't have a homemade semiconductor manufacturing facility in their garage either, I'm sure getting into contact with local waste disposal agencies is a far easier task than building all this stuff.

Re: Home Chip Fab

#40

Post by Junk_Collector »

bogomipz wrote: post #3

This is really fascinating. I apologize if this is a silly question but under the Fabrication section there is a pic titled "physical structure(Texas Instruments, 1997.)" My question is why do all of the components always look so "puffy" or "fuzzy" in these chip zoom-in pics? I guess I'm always surprised that such a precision process produces something with such imperfect looking shapes. Or are these slightly amorpho…

As mentioned in other posts, the process of making these types of devices tend to produce rounded structures. This is a byproduct of using Ion beams, deposition, lithography, etc in manufacture.

BUT, the image is also made worse by how the image is captured. The picture you are looking at is a FIB (Focused Ion Beam) cut cross-section of a transistor which is then imaged by a SEM (scanning electron microscope). Probably in one of their fancy dual source beam devices. Depending on how you cut with the FIB, you can also push material downwards into lower layers and create a waterfall effect that will blur edges. It's can be very noticeable in rookie cuts but doesn't look like a major impact here.

Imaging with the SEM itself can also cause distortion and blurring as trapped charge accumulates on the surface and deflects the electron beam slightly. You can see this where the edges get increasingly bright because charges gather and become trapped at the boundary of the conductive and insulating layers. The image isn't sharp enough for me to tell if that is poly-silicon or aluminum contact traces.

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