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Comment by moconnor | Hacker News Reader

I had a tour of AMD's Dresden fab several years ago, it was literally a building inside a building, with the inner building mounted on shock absorbers to isolate it from vibrations. IIRC the manufacturing chain was entirely automated - silicon in, chips out.

That was several generations ago, I'm looking forward to seeing what is required to manufacture with high yield at 7nm!

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Is it possible for general members of the public to arrange tours of microprocessor fabs anywhere?

With all the clean rooms required, I doubt it, but I don't know.

We have an ultra-clean room. It has a window.

My university has clean rooms, they have windows, the hallways have windows too so you can peek in from outside. Always great to show to visitors :) (at night they have weirdly colored lighting, pink, purple, so it looks really funky, no idea why)

It's possible that when nobody is working in the room, the lights aid in maintaining a sterile environment.

At specific wavelengths (~245-265 nm), (UV) light inactivates quite a few living things. As light is quantized, the purpleish color you see is due to e- stepping down.

My UVC bulbs deployed in a FL home water treatment system pipe out UV in the region of 253.7nm. An ophthalmologist friend pointed out that unfiltered long term exposure to these wavelengths first catalyzes conjunctivitis (pink eye) then conditions go down hill from there. It's suggested that you don't stare directly at sources of this purplish color for any protracted periods.

Nope. Our bio hoods have a toggle switch. Lights off is in the middle, lights on is one direction, UV sterilization is the other direction. To turn the lights on, you have to turn the UV off.

Clean rooms that work with semiconductors use light-sensitive photoresists. I've always dealt with yellow windows and yellow covers over the lights, though in theory pink would accomplish the same thing: keeping blue light off the wafers while you're working with them.

The concept is not at all dissimilar to old-fashioned darkrooms in photography. Outside light will wash out your image.

Certain parts of the cleanroom will look yellow--these are the spaces where they do lithography with resists that are openly accessible to the air. UV-sensitive resists will chemically crosslink in UV light, so they put on filters on the fluorescent lights (or use special lights) that keeps the wavelength away from the higher-energy blues and towards the lower-energy yellows and reds.

It's probably more the secrecy of their process that stops such tours from being available. IC manufacturing involves tons of proprietary trade secrets and NDA'd stuff.

I'm not sure what secrets you would gather from a tour since everything happens in enclosed machinery.

Were you doing the tour as a vendor or a customer?

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