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MiRC Cleanroom Operations
Chemical Safety Training
Microelectronics Research CenterGeorgia Institute of Technology
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Please• Silence your mobile
phones for this lecture
• Wait until a break before answering calls
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Agenda• Terminology• Cleanroom hazards• Safety Practices• Storage and disposal of chemicals• Accidents and emergencies
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I—Terminology• MSDS—Material Safety Data Sheet
– Describes a chemical’s properties, hazards, and safe use policies
• Partial Listing– Chemical Property Terms– Exposure, toxic effects, & exposure levels– Storage & handling– Emergency procedures– Safe disposal & transportation
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Sources of Chemical Information
• MiRC cleanroom website• http://grover.mirc.gatech.edu/safety/• Read “How to Translate a MSDS” • Manufacturers/suppliers
– MSDS included with the first shipment of a chemical
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II—Cleanroom Hazards• Potential hazards inside the
cleanroom– Toxic, flammable, and corrosive gases– Acids and bases– Solvents– Electrical– Sharps—razor blades, broken wafers
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Gas hazards (partial listing)• Pyroforic (Silane)—burns in contact
with air• Flammable (Hydrogen)• Corrosive (Chlorine)• Asphyxiant (Nitrogen, Argon)—will not
support life• These gases are used in process tools
– You will not have to handle any of these gases in any form
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Specific Chemical Hazards• Hydrofluoric Acid
– Corrosive, penetrates skin, destroys tissues and bone
– Pain delay: 1-24 hrs after exposure– Use Calcium Gluconate to treat– 2% exposure can be fatal
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Specific Chemical Hazards• Acetone and Flammable Solvents
– high vapor pressure– can make breathing difficult– extremely flammable– Avoid eye contact– attack the liver– headaches are common sign of
exposure, seek fresh air
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III—Safety Practices• Gas safety• Safe chemical practices• Labware• Proper (improper) methods• Personal protective equipment—PPE• Buddy system
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Gas Safety• Leave all gas maintenance to staff
members• Do not:
– cycle any valves– loosen any fittings– disconnect any gas lines
• Be aware of alarms or any unusual odors
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Safe Chemical Practices• Be aware of possible chemical reactions• New chemicals must be approved by
MiRC staff before bringing them into the cleanroom
• Read MSDS before using chemicals– MSDS are available from web site– Users must provide an electronic copy of
MSDS before brining a new chemical into the cleanroom
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Labware• Make sure that the
labware you use is compatible with the chemicals (or mixtures) you pour into them
• Example: HF will attack (etch) a glass container
Good rule of thumb: use labware made out of the same type of material chemical is stored in
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Proper (Improper) Methods• Improper (shown)
– Do not rinse wafer, or pour solvents down the drain
• Proper– Rinse wafer into
separate waste dish– Pour the contents of
the dish into the waste jug
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Personal Protective Equipment (PPE)
• The following PPE is required while using acids in any hood:– Eye protection– Gloves– Face shield– Apron
• Your cleanroom garment is NOT protective equipment
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Be Advised• Aprons don’t allow
airflow and people often sweat when wearing them
• If the inside of your apron is wet, do not panic. It is unlikely that the chemical has gotten inside the apron
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Buddy System• Two or more people
must be in the lab at any one time
• It is a cleanroom violation to be in the lab alone
• This is for your safety—and it’s the law
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Additional Issues• Contact lenses
– They are allowed—with a warning– Contact lenses may trap chemicals, making
eyewash more difficult– Wear a face shield over your safety glasses
when working in the hoods• Buzzcards come in contact with chemicals
inside the cleanroom, don’t put it in your mouth
• Irresponsible people endanger everyone– Report unsafe practices to the cleanroom staff
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Wet Sinks/Fume Hoods• Fume Hood operation
– The hoods are shared equipment—wipe it down before you leave
• Hot plates– Can cause severe burns– Keep flammables away from the hot
plates• Fume Hood Use
– Do not use until properly trained
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Electrical Concerns• Do not operate equipment with cover
panels removed• Do not operate equipment with frayed
wires• It only takes 0.1 amps to kill you!• For example:
– E-beam evaporator--10,000 volts– Plasma etchers--high power RF– Most equipment runs on 208 volts 60+ amps
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The Bottom Line on Safety• Safety is everyone’s responsibility• You are responsible for your own
safety• Do your homework
– Read the Material Safety Data Sheet (MSDS) for every chemical you work with
– If you do not understand, ask questions
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IV—Storage and Disposal of Chemicals
• Label all individual containers• Change label quarterly• Place old chemicals on storage cart
Dry
box
B13
[email protected]: Rose, Bob
Burdell,George
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User Chemical Storage• Use appropriately
labeled storage cabinets– A= Acids– B= Bases– O= Oxidizers– P= Photoresist,
polymers– F=Flammables
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Chemical Waste• Acids and Bases
– Pour down the drain with running city water
• Solvents & photoresist– Pour into the solvent waste jugs– DO NOT POUR SOLVENTS DOWN THE
DRAIN
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Empty Waste Bottles• Empty acid and bases
– Triple rinse with city water, pour down the drain• Empty solvent bottles (one gallon bottles)
– Rinse with acetone, methanol, and isopropanol and dump the dirty solvent into the solvent waste
– Rinse 3 times with city water then pour down drain• Label rinsed bottles “RINSED” and place them
in the chemical storage chase on the cart • Refill the squirt bottles—do no throw away
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Waste Containers• Place all used/waste chemicals on the
chemical waste shelf in the chemical storage chase
• Do not pour plating solutions down the drain– Place them on the chemical waste shelf– Label the bottle
• Ex: Chrome Etchant Waste, Gold Plating Waste, etc.
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V—Accidents/Emergencies• Emergency Phones• Emergency Response Equipment• Chemical Accidents
– Responding to a spill– Escalation– Transporting victims
• Toxic Gas Alarms• Safety Showers• Evacuation Routes
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Emergency Phones• Emergency phones
– Located throughout the cleanroom:• Hallway• Focus Center• Outside Mask Shop
– Dial x42500 (404-894-2500) Georgia Tech Police• Add this number to your mobile phone
– State the nature of the emergency– Do not dial 911—they will not know
where you are
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Emergency Response Equipment
• Spill response kits– Located inside the cleanroom in the
hallway between the gowning room and the storage room
– Contains:• Acid neutralizer• Base neutralizer• Absorbent material
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Responding to a Spill• You are expected to clean up small
spills you made yourself– You know what you spilled– If you cannot, or are not sure what to do,
call the staff– Report all spills regardless of size– Report all found spills, water leaks, or
unknown materials
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Escalation• First person—you—clean it if you can• MiRC staff• GA Tech Environmental Health and
Safety• HAZMAT• Important—report all spills
– Call GTPD after hours—as well as MiRC staff
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Toxic Gas Alarms• Located on the
cleanroom walls• Sensors located near
the gas source• If the alarm goes off,
evacuate the cleanroom level immediately
• If the alarm is silenced, continue to evacuate and return only once the staff has reopened the cleanroom
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Toxic Gases Used—Partial Listing• Phosphine• Silane• Chlorine• Boron Trichloride• Silicon Tetrachloride• Hydrogen Bromide• Ammonia• Do not take the alarms lightly
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Emergency Showers/Eyewash
• Use the eyewash if you get any chemicals in your eyes– Force your eyes OPEN!– Buddies—make sure the victim stays in
the eyewash for at least 15 minutes, they will lose track of time in the eyewash and think a few seconds is a long time
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Emergency Shower• Use the emergency shower whenever
you are exposed on the torso, head or legs
• Take ALL of your clothes off– Your clothing will trap the chemicals
next to your body• Anyone not directly assisting the
victim must leave the cleanroom
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Transporting a Victim• Minor injuries—other than chemical
exposures—require attention proportional with the injury
• All chemical exposures require hospitalization
• Grady Hospital is the only Level One trauma center in the area
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Transportation Procedure• Call GTPD 404-894-2500 and state the
nature of the emergency• For chemical exposures, use the
Emergency Instruction Booklet located by the phone– Place a MSDS of the exposed chemical into
the booklet– Print extra copies for the police and
ambulance drivers (print at least 5 copies)
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Cleanroom Evacuation Routes
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Evacuation Procedure• Leave the cleanroom immediately—
do not de-gown• Gather at the front of the Pettit
Building on Atlantic Drive• Remove your gown outside
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What’s Wrong With This Picture?
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What’s Wrong With This Picture?• Do not put yourself in a
position that increases the risk of chemical exposure
• Putting your face at sink top level is dangerous– Splash hazard– Inhalation hazard
• Do not rest your hands/arms on the sink surface
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What’s Wrong With This Picture?
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What’s Wrong With This Picture?• Do not lean into
the hood• You expose
yourself to harmful fumes
• Stay behind the sash– (The plastic screen)
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Questions?