MiRC Cleanroom Operations

Nanotechnology Research Center

MiRC Cleanroom Operations

Chemical Safety Training

Microelectronics Research CenterGeorgia Institute of Technology


Please• Silence your mobile

phones for this lecture

• Wait until a break before answering calls


Agenda• Terminology• Cleanroom hazards• Safety Practices• Storage and disposal of chemicals• Accidents and emergencies


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


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


II—Cleanroom Hazards• Potential hazards inside the

cleanroom– Toxic, flammable, and corrosive gases– Acids and bases– Solvents– Electrical– Sharps—razor blades, broken wafers


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


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


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


III—Safety Practices• Gas safety• Safe chemical practices• Labware• Proper (improper) methods• Personal protective equipment—PPE• Buddy system


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


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


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


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


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


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


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


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


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


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


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


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


User Chemical Storage• Use appropriately

labeled storage cabinets– A= Acids– B= Bases– O= Oxidizers– P= Photoresist,

polymers– F=Flammables


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


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


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.


V—Accidents/Emergencies• Emergency Phones• Emergency Response Equipment• Chemical Accidents

– Responding to a spill– Escalation– Transporting victims

• Toxic Gas Alarms• Safety Showers• Evacuation Routes


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


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


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


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


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


Toxic Gases Used—Partial Listing• Phosphine• Silane• Chlorine• Boron Trichloride• Silicon Tetrachloride• Hydrogen Bromide• Ammonia• Do not take the alarms lightly


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


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


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


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)


Cleanroom Evacuation Routes


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


What’s Wrong With This Picture?


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


What’s Wrong With This Picture?


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)


Questions?

MiRC Cleanroom Operations

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