[kooglof]

Hi all,

I have a rather specific question regarding the content of a possible job for me in science (postdoc in academia). The job would imply do deal times to times with hydrofluoric acid (HF) in cleanroom, for wet etching of Si in particular.

My background is more in physics - I have no previous experience in such techniques. Of course, I browsed the web and I know that this compound is very nasty and I am aware of the safety procedures.

Those who have experience could tell me more in the sense, is it reasonable for me to adapt to such technique as my first experience in chemical etching? Did you feel a specific stress linked to this particular step in the processes? Is is really different from other chemicals regarding the feeling/danger of the operator?

Thanks a lot, it would clarify the way I see this job.

kooglof

[Arkcon]

I would start with the information in this thread:  http://www.chemicalforums.com/index.php?topic=56444.0  and maybe search our forum for similar threads.

[Enthalpy]

Nearly every person working in a clean room has no previous experience with chemicals - and many chemicals used at semiconductor processing are really nasty. HF harms by contact essentially, while inhaling hydrazine is a bad idea and silane detonates - not to mention phosphine, phosgene and a few more.

Of several dozen clean room colleagues, we all used HF regularly, only one got a drop on his wrist. He rinsed very approximately and had later to go to the hospital where surgeons cleaned his bones. He kept a wide red spot for weeks and a surgery scar, no permanent damage to my knowledge.

So HF is not what would keep me away from semiconductor processing.

[Arkcon]

Well, in a number of threads, we have some useful tips on handling HF.  But ... um ...

and had later to go to the hospital where surgeons cleaned his bones.

Some more specificity would be nice.

[Enthalpy]

"Later" means on the same day, as the colleague felt persistent itch and his skin got red locally.

I believe he had cleaned the drop away with a cloth but not rinsed, or maybe just with a cloth and little water. Correct washing would have needed to exit the cleanroom in order to remove the clean clothes, then put again the clean clothes to reenter the clean room, what he definitely didn't.

"Clean the bone" is what I heard thereafter, not necessarily correct. What's clear is that he has a surgery scar at the wrist since then. Maybe the surgeon soaked the flesh extensively.

So
- skin contact with HF is definitely undesireable
- immediate proper action would have made things easier
- from one drop and thanks to surgery, the consequences were limited
- he went on using HF and so did we.

[Arkcon]

Yeash, that's a weird occurrence.  One time, after working with HF, I  also got red locally.  I didn't think I'd spilled some HF on myself, but I wasn't sure.  I went to the emergency room, but they were no help.  They either didn't know what to do, or wanted to call a hand surgeon.  In the latter case, I would have ended up with the new nickname -- Lefty.