Doesn't litography use some pretty wild chemicals. Like Chlorine Trifloride? Thing that when burned emits hydrochloric acid and hydrofluoric acid. Aka thing that burns ashes. Again.
I assume making those machines is pretty crazy as well.
Sometimes, yes. Interestingly these ridiculously reactive materials aren't the ones that tend to contaminate the environment most; they don't last long enough outside a carefully controlled lab. It's, surprisingly, the almost nontoxic materials like perchloroethylene that tend to cause big headaches, because they're unreactive enough to survive in the environment for many years.
Elemental fluorine is nasty toxic, but it doesn’t really pollute the environment because it’s too busy oxidizing the first thing it finds and forming a never gonna let you go bond.
There are certainly plenty of nasty fluorine compounds, but they too are quite reactive and quickly bind to something[1].
On a tangent from that link: “Fluorine is a naturally-occurring, pale yellow-green gas with a sharp odor.” What lunatic went sniffing fluorine gas and how did he have any sense of smell after doing so?
I hear it's a strong enough odor, and it's good enough at escaping containment, that fluorine chemists can't avoid smelling it from time to time, and there are levels where it is detectable but not especially dangerous. It occurs naturally in trace amounts in fluorite exposed to radioactivity, so crushing some fluorite and smelling it may be a way to get acquainted without risking your life. (It doesn't occur naturally in very many places.)
There are some fluorine compounds that are far less reactive than things like HF, but still toxic; perfluorooctanoic acid is the most notorious one. Naturally these are the ones that are most used to synthesize fluorine compounds.
I worked at a facility with experimental lithography machines. One of the
nasties looked like water, but would pass through your skin and melt your bones. Fun.
Hydrofluoric acid, though I don't think it melts your bones in a dramatic/fast way. It seems to be partially so dangerous because it doesn't "burn" right away, and as you say, is absorbed quickly in skin. So you might not rinse it off quickly.
"Piranha solution" (sulfuric acid, water, and hydrogen peroxide) is closer to what tv/movies portray hydrofluoric acid being like. That is, being able to disappear a body in it.
> It seems to be partially so dangerous because it doesn't "burn" right away, and as you say, is absorbed quickly in skin. So you might not rinse it off quickly.
It seems to be dangerous in a lot of different horrible ways. It's always fun reading an MSDS for substances like this: https://www.airgas.com/msds/001077.pdf
I worked at IGNS in NZ and they used it for dissolving rocks. Many warning signs.
[edit: to clarify I mean safety warning signs, not warning signs of being in contact with it. My assumption is excruciating agony which would be a good indicator :D]
HF keeps regenerating itself until it hits bone and forms calcium floride. Get exposed to enough of it and it will pull the calcium out of your cells, stopping muscles, heart beats, and neuron firing.
I'm not sure what concentration IGNS was using it in as I'm mercifully a computer person, but I had a friend who worked in their labs and took me through them one time :D
The one of the widely used light sources for EUV lithography uses a laser to zap molten tin to get the tin plasma to ionize and emit EUV light. It's fairly exotic and really inefficient but is needed for the smaller node sizes.
It doesn't really sound like this was a fab though. Just a factory that builds tools for fabs. So who knows, but chances are that this factory doesn't operate with the worst stuff.
Found this on the wiki, quoting the rocket scientist John Drury Clark:
> It can be kept in some of the ordinary structural metals—steel, copper, aluminum, etc.—because of the formation of a thin film of insoluble metal fluoride that protects the bulk of the metal, just as the invisible coat of oxide on aluminum keeps it from burning up in the atmosphere. If, however, this coat is melted or scrubbed off, and has no chance to reform, the operator is confronted with the problem of coping with a metal-fluorine fire. For dealing with this situation, I have always recommended a good pair of running shoes.
This is a quote from Ignition! - a very very very good book about liquid rocket fuels. PDF is available online after a quick google. A must read for anyone on HN - imagine what it’s like to be a rocket fuel hacker.
Absolutely. There is a reason that berms between buildings is one of the strong signals of a solid fuel rocket facility when one is analysing satellite imagery.
The mound of earth is there to redirect any potential explosion upwards hopefully protecting the rest of your facility if one building goes boom.
Many things are still unclear including:
- how big the damage is - how long it takes to operate again - how it was possible to happen/how it happend
The linked article basically says the same.