Title: CHEN/PHGN/MLGN 435/535 Safety Rules
Supervisor: Reuben T. Collins (originally prepared by Colin Wolden)
Purpose: To establish minimum safety rules to be followed during participation
in the CSM silicon processing laboratory.
The Rules:
1. Always work in the laboratory with a teammate and/or notify a lab supervisor
that you are in the lab.
2. Tell your supervisor immediately about any unsafe situation.
3. If you are not sure if a situation is safe, ask your supervisor.
4. If you are not sure how a piece of equipment works (or how it is put together),
ask your supervisor.
5. If someone is using the spinner, all persons in the laboratory must be wearing
safety glasses. The person using the spinner is responsible for making sure
this is followed.
6. Wear gloves, lab coats, and safety glasses when handling chemicals for cleaning,
etching, stripping, etc. 'Chemicals' are defined as any substance besides water.
For handling Caustic acids and bases, two layers of gloves and a safety shield
as well as safety glasses are required.
7. Dispose of chemicals properly
8. Ask for training before handling chemicals and/or equipment.
9. Wash your hands when you leave the laboratory or anytime you think they may
have directly contacted chemicals.
10. No food/drink/smoking in lab at any time. Always wear booties in the lab.
Discussion of Rules:
1. Always work in the laboratory with a teammate and/or notify a lab supervisor.
If you are handling equipment and/or chemicals only do so with a teammate or
supervisor.
2. Tell your supervisor immediately about any unsafe situation.
Use good judgment. For example if you see a beaker of unknown chemical origin
sitting around without a label, report it.
3. If you are not sure if a situation is safe, ask your supervisor.
Use common sense. There are no unexpected dangers in the labs, but do not work
with any chemicals/equipment that you do not fully understand.
4. If you are not sure how a piece of equipment works, ask your supervisor.
The value of the equipment that you will be using in this lab is probably in
excess of a million dollars. Unless you are 100% (as in willing to accept the
responsibility of breaking it) sure of what you are doing, ask a supervisor.
5. If someone is using the spinner, all persons in the laboratory must be wearing
safety glasses.
The spinner sometimes breaks wafers. When this happens (about once every thousand
wafers) silicon chards go flying through the air. These pieces are as dangerous
as broken glass. Thus all persons in the lab need to be wearing safety glasses.
It is a good habit to always wear safety glasses whenever in the clean room,
taking them off only to examine wafers in the microscope.
6. Wear gloves and safety glasses when handling chemicals.
Some of the common chemicals that you will encounter in lab:
Photoresist: Photoresist is dissolved in organic solvents not too different
from gasoline. Like gasoline they are quite volatile, so you always want to
keep the top on photo resist containers to prevent exposure and to ensure the
quality of the photoresist. Also, as much as possible always handle photoresist
in the fume hood to minimize exposure. Photoresist fumes have been correlated
with causing birth defects when inhaled by pregnant women.
Developer: Used to remove photoresist, this is basically sodium hydroxide. This
is the same chemical found in Draino or lye, which is used to dissolve clots
in your plumbing. The developer is diluted in water, so it is not very dangerous,
however it will burn your eyes much like getting soap in your eyes.
Acids: Acids are corrosive, particularly at the elevated temperatures which
we use to clean our wafers. For these three classes of chemicals the treatment
for accidental exposure is the same, rinse with water.
Hydrofluoric acid (HF): HF is used for etching oxides. HF is more dangerous
then it seems. If HF contacts the skin it does not hurt, so people can get careless
about it. HF passes through the skin and looks for calcium to eat (your bones).
Pain caused by HF will not start for a few hours, but it may last for days.
For HF exposure, notify your supervisor and seek medical help immediately.
Clothing: We will have two types of gloves, thin vinyl or latex gloves, and
thick neoprene gloves. Thin gloves should be discarded after working at a chemical
station. If exposed to chemicals, immediately discard, wash hands, and get a
new pair. Thick neoprene gloves should be rinsed with water after use before
storage. Long sleeve shirts are recommended. Open-toed shoes are not allowed.
Wear labcoats when handling chemicals to protect your clothing. (Photoresist
stains never come out). Note, when working with caustic acids and bases, and
especially HF, required attire is thin gloves, neoprene overgloves (two pair
of the thin gloves maybe used), lab coat, goggles, and face shield.
7. Dispose of chemicals properly.
Part of using chemicals involves disposing of chemicals. NEVER EVER throw chemicals
down the drain. Dispose of in properly labeled containers. Be careful not to
mix wastes, (i.e. what happens when acid waste and solvent waste are mixed?).
8. Ask for training before handling chemicals and/or equipment.
This includes the characterization equipment as well as the processing equipment.
9. Wash your hands when you leave the laboratory or anytime you think they
may have directly contacted chemicals.
Just a good habit to get into.
10. No food/drink/smoking in lab at any times. Wear booties at all times.
The first goes without saying. The second is to minimize dirt.
Acknowledgment:
I have read these two pages of rules. A supervisor explained them to me and
answered my questions. I have my own copy, and I am signing this copy to show
that I understand these rules, and that I will obey them.
Supervisors Initials _____________
___________________ _____________________ _________________
Print Name Signature Date