Everyone working in the NanoLab should have received the LION safety regulations and have read them thoroughly.
([https://www.science.leidenuniv.nl/en/information-for-employees/ohs-department/laboratories] safety_lion.pdf ).

The faculty course about chemical safety should be followed as well as the fire extinguishing drill (follow these at the first opportunity).

You should be able to locate:

• The fire extinguishers in each room
• The emergency off-switches in each room
• Eye showers of each chemical working place
• Emergency showers on each side of the floor
• Point exhausts
• Fire alarm

The general idea is: if you are not sure, ask. Some of the situations you can encounter where you should consider your safety are: chemicals, high voltages, RF radiation, X-rays, heavy objects, sharp objects etc.

When you want to start working with chemicals, read the following document: Working with chemicals

Be very careful to avoid eye contact with all chemicals. If you get strong alkalies like resist developers in your eye your vision will almost certainly be damaged! Avoid all skin contact with anorganic chemicals (acids and bases) and avoid their vapours by working in a fume hood. Avoid skin contact and especially inhalation of organic chemicals by working in a downflow bench, cleanbench or fumehood.

Always hold a bottle with 2 hands and never even think of just holding the cap. Some organics require evacuation of the building if you drop a bottle! If a bottle breaks and chemicals are spilled there may be an explosion danger. Walk to the 3 button wall panel and switch all 3 buttons off so that the room is completely shut down, then warn Daan Boltje or Marcel Hesselberth.

Each cleanbench / downflow bench / fume hood has an eye shower on top. Eye showers are single use! Do not twist the cap out of curiosity, once opened they cannot be closed and must be discarded. If you get covered by chemicals there are showers in the hall on each side of the floor.

MSDS's of all used chemicals are present.

Do not stick your hand in very strong ultrasonic agitators, it may cause decompression sickness.

We try to make our lithographical processes as 'green' as possible by replacing chlorobenzene by anisole and by using ethyl lactate instead of carcinogenic alternatives, for example. Be careful with THFA.

Frequently used chemicals are:

• Acetone
• Anisole
• Cyclopentanone
• Ethanol
• Ethyl lactate
• IPA
• Ma-T
• MIBK
• NMP
• THFA
• Xylene
• HCL
• HNO₃
• HF
• H₃PO₄

You can look up the MSDS at http://www.chemexper.com. Many links to MSDS site can be found at http://www.ilpi.com/msds/.

Use demi water for making etch chemicals, NEVER normal water from 607! Demi water is a chemical, do not drink it (it depletes you of minerals).

When working with acids, always wear gloves and work behind the glass of the downflow bench / fume hood or wear safety glasses (available in the 'magazijn'. If you work with HF be extremely careful. HF is not a very strong acid but it is exceptionally destructive. A small area of the body covered with HF is lethal. The only way to neutralize HF is with Ca, it is obligatory to have Ca pills or creme close when you use HF. Be careful when disposing strong acids, strong exothermal reactions can occur upon mixing with other chemicals.

Safety glasses are mandatory! Always! Wear gloves as well. Be careful when disposing strong bases, strong exothermal reactions can occur upon mixing with other chemicals.

There is no type of gloves that protects the user from all known chemical hazards. The two currently available types are Nitrile (blue) and Latex (milky-white). Use the following link to decide which type of gloves you should use to protect your hands from most common chemicals found in clean rooms: http://www.safeskin.com/ChemResist/search.asp?o=1 An exaustive list of all possible chemicals and hazards is here: http://www.pp.okstate.edu/ehs/HAZMAT/gloves5.htm

Both types will protect your sample from your fingerprints; however, it is very important to use
NON-POWDERED gloves (these words should be clearly stated on the box).

The chemical compatibility of plastic tweezers chemical_compatibility.pdf

• CF = PA66/CF30 polyamide 66 reinforced with 30 wt% carbon fibre
• CP = PEEK/CF30 polyetheretherketone reinforced with 30wt% carbon fibre
• LC = PPS/GF30 polyphenylene sulphide reinforced with 30wt% glass fibre
• LP = PPS/GF30 polyphenylene sulphide reinforced with 30wt% glass fibre

Powders have a large surface/volume ratio, this increases the reactivity/toxicity. Heavy metals are toxic, some in small concentrations. Some metals (for example Ce) burn spontaneously in air. Take these considerations into account when opening vacuum chambers.

Gases under pressure can be very dangerous, work on gas cylinders and lines should only be done by technicians. O₂ at high partial pressures poses fire/explosion danger. Do not pump O₂ with normal rotary pumps. SF₆, Cl, and other etching gases are very toxic. Inert gases are dangerous because they displace air, so breathing Ar is dangerous (First aid: hold victim upside down). Do not breath He to get a funny voice! It can cause lung damage.

Many systems work with very high voltages, and in some cases HV power supplies can deliver significant current (several amps). The systems are equipped with protection circuits but these can never cover all possibilities, so when you disconnect power supply cables to connect them to a different sputtering source for example or when you open vacuum systems be very careful that the mains are switched off.

Also be careful with water leaks in electrical systems (sputtering sources are water cooled) and with jewelery (a necklace can dangle through the ventilation slits of an electric box and is therefore not allowed).

Thin film fabrication and structuring requires clean conditions. Therefore, it is absolutely necessary that work in the laboratories is done in a disciplined manner and that there are rules to guide this in order to create a reproducible environment for the samples.

The laboratories are not randomly arranged. If you find a cleanbench that has chemical bottles on the right and substrates on the left this is to avoid objects in the middle to cause turbulence in the laminar crossflow (look at the guidelines for using laminar flow equipment in the sputtering lab).

No powder/dust producing activities should be performed in the cleanroom so a diamond cutter cannot be found there.

When you are done, things should be left behind the way you found them or tidier!

NEVER remove items from the rooms. It is very irritating if you have to look for 20 minutes for a diamond cutter or some other trivial item.

The cleanbenches and tables in the labs are not sample storage spaces. If samples are found there they will be immediately removed and stay for a month or so in the 'cupboard of shame', the trash can is the next destination.

A quick overview of DO's and DONT's:

• DO refill the wash bottles when they are almost empty (10%)
• DO empty the 1 liter waste bottles (wetbench cleanroom, cross flow sputter lab) in the big waste container (red label)
• DO replace acetone/ethanol/IPA when you finish a bottle (you can find full bottles in the yellow chemicals cabinet in 607; yes you need to get out of the cleanroom for it)
• DO inform me when we are running low (10%) on consumables (developers, resists, organic solvents, etc)
• DO NOT put empty bottles back on the shelf!
• DO NOT think it is the responsibility of someone else to refill or inform me. These things do not magically happen by dwarfs in the late evening!

At the places where you can use glasswork you can find it clean. After use, clean the glasswork!

Low glasses are meant for organic chemicals and should be cleaned by rinsing with acetone (NEVER let gloves come in contact with acetone in a glass, it will cause latex to deposit at the wall that is very persistent and can be found on many samples to come) and twice with IPA.

High glasses are meant for anorganic solutions and can be used in the cleanroom ONLY. These glasses are never allowed to contain any particle residue. Cleaning is done with the water spray gun and subsequently in the 3 stage demiwater flow cascade.

HF etches SiO₂ very well, never put it in glass, use fluorware instead.

N.B. Slurry from the wiresaw is never allowed to enter the NanoLab! (clean it away with ethanol somewhere else, i.e. in 607 and NEVER use glasswork from the sputtering lab or cleanroom for that!

Refill spray bottles when you almost empty them. Spray bottles are NEVER allowed to leave the room they are meant for. Refill them only with what the label says and ONLY PA GRADE CHEMICALS from the top shelve of the cupboard in 607. The chemicals on the left of that shelve ore only allowed to be used after instruction. If supply is running low, warn me.

Organics go in the organic waste bottles. When full, empty them in the container in 607. If the container is full, exchange the container at the ground floor in the yellow cupboard in front of the cryogenic department.

Strong acids and bases go in the container in 607, after neutralization. Very weak aids/bases in very small amounts can be disposed in the cleanroom.

The containers are colour labelled and have pictograms on them.

• Used oil: green colour code, no pictogram
• Organic waste: red colour label, left pictogram below
• Acid waste: no colour label, right pictogram below

If you are unsure, ask. Never mix chemicals (waste or other) if you are not 100% sure.

Never move anything else than substrates into the room and never remove anything else than ready samples out of the room. Equipment in the room, including multimeters, silverpaint etc. stays there. Tools are all UHV clean.

Clean up and dry the surface after use (much better than you clean the sink at home)

Place washbottles and other items the way that is indicated on the cleanbench plan. Clean up and dry the surface after use (much better than you clean the sink at home)

Never use the spin coater without aluminum foil inside. Clean away resist spills immediately. Clean up the clean benches after use (much better than you clean the sink at home)

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Notify me when chemicals and other consumables are about to be finished.

Use the right color codes! If a waste can is full, exchange it at the chemical waste storage (yellow cupboards in front of the cryogenic department).

Clean up and dry the surface after use (much better than you clean the sink at home)

Nothing except people and microscope specimen go in and out of the room. Never borrow anything without notifying me. On the SEM column you can find:

• Clean stubs
• Gloves
• Mounting tools (Allen keys, tweezers etc.)

and nothing else. Clean the used stub.

On the preparation table you can find solvents. If you finish any of the consumables, you must replace them (supply is in 607). Tables must be clean after use. Never place liquids on the SEM column or on the terminal table. See also the FEI NanoSEM 200 page.