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Antique 4x5 camera creates 20 micron photolithography masks [video]

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Re: Antique 4x5 camera creates 20 micron photolithography masks [video]

#41

Post by strstr »

bkraz wrote: post #24

Hi. I'm the creator of this video. Let me know if you have any questions.

Did you ever get the low temp vantablack working as expected? I’m guessing oxygen is passivating the aluminum surface somewhere in the process, and the paper doesn’t document how careful they were. I’d personally want to do this under a nitrogen atmosphere, but I’ve never sonicated under a controlled atmosphere.

I’d bet the reason you can sort of get aluminum to blacken over the heated beaker has something to do either with the fact that the beaker is effectively positive pressure and pushing out everything but water vapor, or that the condensed watervapor on the surface of the aluminum is consistently oxygen free.

I find the former somewhat less believable than the latter, but it’s been a while since I’ve worked on things like this.

Re: Antique 4x5 camera creates 20 micron photolithography masks [video]

#42

Post by ginko »

tasty_freeze wrote: post #39
splintercell wrote: post #10

Cringing it everytime he calls it an antique camera. This is like a millennial talking about an antique technology called 'VHS' tape.

Go to craigslist (for a large city) or ebay and search "vintage computer". Stuff produced in the 90s is considered vintage.

This is a camera, not a computer. This monorail 4x5 camera is pretty much still the state of the art for studio large format photography.

Re: Antique 4x5 camera creates 20 micron photolithography masks [video]

#44

Post by abainbridge »

bkraz wrote: post #24

Hi. I'm the creator of this video. Let me know if you have any questions.

If you used your microscope slide as a mask to do photolithography on silicon, you'd use an optical reducer, right? So the feature size on the silicon could be ~5x smaller?

Re: Antique 4x5 camera creates 20 micron photolithography masks [video]

#45

Post by foldr »

tasty_freeze wrote: post #39
splintercell wrote: post #10

Cringing it everytime he calls it an antique camera. This is like a millennial talking about an antique technology called 'VHS' tape.

Go to craigslist (for a large city) or ebay and search "vintage computer". Stuff produced in the 90s is considered vintage.

Vintage != antique, and ginko is absolutely right. You can buy the exact same kind of camera brand new today:

https://peartreephoto.com/sinar-p3-view-cameras/sinar-p3-df?...

(Ignore all the marketing copy about digital. Anyone dropping this amount of money on a monorail probably would be using it with a high-end digital back, but that's not included in the price, and the camera above could perfectly well be used with a film back too.)

Re: Antique 4x5 camera creates 20 micron photolithography masks [video]

#46

Post by mmcwilliams »

Palomides wrote: post #5
madaxe_again wrote: post #4

I used to travel with a crown graphic - pretty much the same camera as in the video, shooting colour positive. You can do some great stuff with them, and tilt-shift is trivial, if that’s your thing. Quality on slow film is just crazy - I’ve a shot of an ex, she’s half-frame, and you can see the second hand on her watch - you can get very fine focus with a loupe, and having a Polaroid back to do some instant tests was…

I literally just bought a box of the film he's using here, it's a high contrast red-insensitive film, $15 for 50 sheets, https://www.freestylephoto.biz/531345-Arista-Ortho-Litho-Fil... developing it for normal contrast images is more difficult but not impossible

Greatly reduced Rodinal, on the order of 1:100, will bring some "normal" tones out of hi-con film. At $0.30 a sheet it's not a bad experiment.

I was gifted a roll of expired Kodak Imagelink microfilm stock and once it's cut down to sheets that's my development plan for it. Similar tonal range and ISO.

Re: Antique 4x5 camera creates 20 micron photolithography masks [video]

#47

Post by bkraz »

bane wrote: post #35
bkraz wrote: post #24

Hi. I'm the creator of this video. Let me know if you have any questions.

Awesome video and process, we've been talking about this at work since it showed up here and have a few questions if you don't mind: How far do you think you'd be from making a simple 8-bit CPU like a 6502? Have you thought about illuminating the initial film exposure as well as the substrate exposure (on the slide glass) using monochromatic light sources like a mercury UV lamp? Instead of a vacuum pump to flatten th…

Thanks! I'm very far from making a CPU. Check out Sam Zeloof's work to see some of the other parts of home IC fabrication. Creating the mask is just one part of the process, and dialing in diffusion, oxide growth, metal deposition would take a lot of additional effort.

Yes. My original attempt (years ago) was to use a standard photographic enlarger: replace the lens with quartz, place the paper or plastic master design on a UV light source on the table, then place the microscope slide with photoresist in the enlarger where the film would normally go. One problem is the lens is not setup to cover a whole microscope slide. Another problem is not enough UV light getting through the whole optical system -- exposure would have been hours if it worked at all.

Haven't tried electrostatic. Considered low-tack adhesive (3M post-it).

Re: Antique 4x5 camera creates 20 micron photolithography masks [video]

#48

Post by bkraz »

abainbridge wrote: post #44
bkraz wrote: post #24

Hi. I'm the creator of this video. Let me know if you have any questions.

If you used your microscope slide as a mask to do photolithography on silicon, you'd use an optical reducer, right? So the feature size on the silicon could be ~5x smaller?

I believe current tech uses 4x reduction from masks down to actual chips. This works well with sizes needed for quartz lens systems, etc. Older processes used 1x reduction (either direct contact, or very tiny offset). This is cheaper and easier because you don't need any quartz lenses, which are needed instead of standard glass for their UV transmission ability.

Re: Antique 4x5 camera creates 20 micron photolithography masks [video]

#49

Post by abainbridge »

bkraz wrote: post #48
abainbridge wrote: post #44

Earlier quoted context omitted.

If you used your microscope slide as a mask to do photolithography on silicon, you'd use an optical reducer, right? So the feature size on the silicon could be ~5x smaller?

I believe current tech uses 4x reduction from masks down to actual chips. This works well with sizes needed for quartz lens systems, etc. Older processes used 1x reduction (either direct contact, or very tiny offset). This is cheaper and easier because you don't need any quartz lenses, which are needed instead of standard glass for their UV transmission ability.

Interesting. I've got a 180nm mask from a previous job. It's obviously a larger scale than the finished chip. Could be 4x. I think it is from TSCM, circa 2003, for mixed signal CMOS.
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