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TL;DR: stressful. need to think constantly. noisy. need to be constantly aware of your surroundings. bloody dangerous. need to behave in a certain manner. The air is nice (intetionally ionised) and clean.I will attempt to give you a hint of what it's like by showing you the device lab of the EPSRC National III-V Centre in Sheffield, UK.Note that this isn't a fab, it's just a lab, hence only low-volume, largely academic devices are made. We don't do silicon chips, but deal with GaAs, InP, GaN, occassionally AlSb and other exotic substrates. Generally, they are used in photonics (lasers, interferometers, etc.) and niche high-speed devices that must outperform Si.Whatever happened to Gallium-Arsenide? Why did the need for GaAs go away? What technology solved the problem it was supposed to address?How does a "clean room" really stay clean?What happens if you sneeze in a clean room? Why are the 'bunny suits' in clean rooms sufficient, if they aren't even pressurized/sealed?How often does the clean room in a microchip factory get dirty?Even if I'm not showing much, because the nature of those pictures may be sensitive, I would ask that you have the courtesy of a PM before publishing this to your blog.The building is designed from the ground up to reduce contamination.First, the entrance. The mundane grill is somewhat common in corporate environments. Because it's so large, it's unavoidable, and if you walk over it, it will do a decent job to scrape the excess mud on your soles. Mud is a given here.Then you go to the cleanroom. We have an access system that shows who is in on a web server. Now we know how many bodies we need to retrieve if there is an explosion/poisonous gas release.As soon as you enter, you're greeted by this ugly, sticky, perpetually dirty, rubber mat. Here's why:Contaminants are inserted everywhere, and this is the second important measure. The third is hinted in the picture.Lamarflo is a company that makes expensive air conditioning with laminar flow:The air must perpetually circulate from up to down, forcing heavy particles to the ground, so they can easily be mopped. In case you ask, yes, it feels drafty, but because the humidity is kept at a constant 40% (too little and you faciltiate electrostatic discharge, too much and risk condensation) and temperature at a relatively pleasant 22C, it doesn't feel so bad.There will be vents forcing air out towards fire escapes. The doors will never be sealed, and by forcing the air out, dust goes out, not in.ok, let's move on.Put overshoes on. this is both for hygenic and contamination reasons. Some professional cleanrooms may have dedicated ESD shoes for each employee, but that precludes the possibility of visitors (and if you have a cleanroom, you really want to show it off).Next, we go over one of these sticky mats, to remove as much gunk left on the covered sole.passing through an airlock, we get to the changing room:and remember to wash your hands.You need a full hood (covers your hair), a onesie (covers your clothes) and oversized overshoes. In the end you look like a blue clown.Notice the blue sticky mats everywhere. They're there for a reason, so step on them!Once fully suited, you're ready to go into the lab area. After another airlock and security log-in, put on your gloves (they're there to protect the semiconductors from you, and you from all the nasty chemicals lying around).Probably you will work on a 'wet bench' like these. Cleaning happens everywhere. One way is to dip the sample progressively into n-butylacetate, acetone, and isopropylic alcohol. Then dry it with the dry nitrogen gun in there. Notice the work area is tidy, and everything is labelled. Keep it tidy. Don't mix chemicals randomly. By the time you got into the lab you have a process checklist and you need to follow it to the letter.There are many, many possible design stages that may involve plasma machines. They're beautiful to watch, sadly, I haven't cleared if I can take pictures.Not decorative:Most often, the lab is a spectacular maze of pipes with fluids of varying toxicity. Furtunately, the laminar flow and other vents, insulations coats, and so on should minimise the risk of sudden death in the unlikely event of a rupture (biggest earthquake is Richter-4, and the facilities are unlikely to be high up on a terrorist target list).So at some point, you are bound to etch a pattern on the semiconductor, and the most used method is via UV photolitography. hence the yellow room, which can be disorienting at first.Of course, there is an assorted mixture of chemicals here, all more toxic then the others, so if you're not wearing gloves and glasses PPE at this point, shame on you. The blowers inside the fume cabinets force down and prevents inhaling toxic vapours.The jar in the picture normally contains waste solvent. If I took it out with the lid off, I wouldn't be able to breath, because it's very irritant for the respiratory system. The constant freshly filtered air flow pushes the vapour down, and keeps it away from my nostrills. Extractor fans also need to be in place, otherwise this wouldn't work properly.Assortment of poisons. These are used for spin coating, one cheap way of distributing photoresist relatively evenly along a sample. The black thing on the left is a hot plate, for curing.Ordinarily, these are a set of rules that need be followedyou can't bring in paper or notebookssame for laptopsmobile phones are contraband in high standard cleanroomsideally you shouldn't breathe, but that's not possibleyou shouldn't jump, run around or do anything stupid that can invite an accident or introduce extra contaminationyou should report anything that looks, smells or feels funny, even if it turns up to be ok. even your colleagues.no personal belongingsdon't touch stuff. better yet, if you don't know what it does, don't even look at it. (may be overruled by the looks funny rule)don't leave airlocks open for longer than necessarydon't drop anything on the ground, work benches, wet benches and so on.clean everythingclean everything between every processclean & check after each processdon't use stuff you haven't been trained to usedon't mix chemicals. water is a chemical. think.observe the fire, toxic gas and oxygen depletion alarms.Hopefully this will give you a glimpse on how a semiconductor lab is. A commercial-scale lab will be similar, but with more restrictions and a lot more robots.Note: all personal protection equipment is designed to minimise risk, rather than avert it. Once your gloves touch chemicals, you should either make an effort to clean or discard the gloves, depending on what chemical it was. For that matter, if you are careful, spills and splats never happen, but it's far easier to be tired and/or careless. This is why robots are so prevalent: they're reliable, efficient, and get reproducible results.Bonus round: here is a frozen liquid nitrogen line after filling a dewar (a special double-walled barrel)And the permafrost with the big storage tank outside. Other storage units are on the top of the building, hidden from view, as they should be.Here is (now Professor) Tao Wang describing some manfuacturing steps and challenges in high brightness GaN LEDs.Also refer to the introductory clip here (cannot be embedded on Quora)http://www.shef.ac.uk/eee/pgt/photonicsOccasionally, you get to work with monsters like these: (molecular beam epitaxy):and these:Sometimes liquid nitrogen flows around freelyIndustrial cleanrooms kick it up a notch. We're disgusting blighters as @Jacob VanWagoner puts it, and sometimes to remove the particle contamination, you need to remove humans. Failing that:And the semiconductor material is never actually in touch with the room, so it is kept in an even cleaner state. The rails on top contain the boxes which contain a pancake of wafers.They yellow lights are used to prevent photosensitive material from degrading, such as photoresists, which reacto to blue and UV light, which tpyical fluorescent lamps have plenty of.