MiRC Cleanroom Operations

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MiRC Cleanroom Operations
Microelectronics Research CenterGeorgia
Institute of Technology
Chemical Safety Training
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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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ITerminology

• MSDSMaterial Safety Data Sheet
• A MSDS is a document that describes a chemicals
  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
• Include a MSDS with the first shipment of that
  chemical

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IICleanroom Hazards

• While working in the cleanroom, you will use
  various chemicals to process your wafers and the
  following (potential) hazards
• Toxic, flammable, and corrosive gases
• Acids and bases
• Solvents
• Electrical
• Sharpsrazor 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)not hazardous as
  described above but will not support life
• You will not handle these gases (cylinders) in
  the cleanroom, but you will use them in process
  toolsetch and deposition systems

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Specific Chemical Hazards

• Hydrofluoric Acid
• Acetone and Flammable Solvents
• Chlorinated Solvents

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Hydrofluoric Acid (HF)

• Highly corrosive, readily penetrates the skin,
  causes deep tissue layer destruction and
  destruction of bone, pain may be delayed from 1
  to 24 hours, therefore early treatment is very
  important. Use Calcium Gluconate gel for
  treatmenttubes are located near each fume hood.
  Calcium Gluconate is not a burn ointment
• Literature indicates that HF exposures of as
  little as 2 of body area have been fatal.

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Acetone and Flammable Solvents

• These solvents have a high vapor pressure
• These fumes can make breathing difficult
• They are extremely flammable
• They cause extreme pain if splashed in the eye
• Like alcohol (a solvent), they attack the liver

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IIISafety Practices

• Gas safety
• Chemical usage
• Safe chemical practices
• Proper (improper) methods
• User chemical storage
• Personal protective equipmentPPE
• Buddy system

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Gas Safety

• Do not cycle any valves
• Do not loosen any fittings
• Do not disconnect any gas lines
• Be aware of alarms or any unusual odors

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Chemical Usage

• Chemical practice
• Labware
• Chemical storage
• Chemical supplies

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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

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Proper (Improper) Methods

• Improper (shown)
• Do not rinse wafer, or pour solvents down the
  drain
• Proper
• Use the solvent waste jug or beaker
• Pour the contents of the beaker into the jug

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Personal (Personnel) Safety

• Personal Protective Equipment
• Buddy System
• Contact Lenses

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Personal Protective Equipment (PPE)

• The following PPE is required while using
  chemical in any hood
• Eye protection
• Gloves
• Face shield
• Apron
• Your cleanroom garment is NOT protective equipment

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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 safetyand its the law

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Additional Issues

• Irresponsible people endanger everyone
• Report unsafe practices to the cleanroom staff
• Contact lenses
• They are allowedwith a warning
• Contact lenses may trap chemicals, making eyewash
  more difficult
• Wear a face shield over your safety glasses when
  working in the hoods

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Wet Sinks/Fume Hoods

• Chemical bench operation
• The hoods are shared equipmentwipe it down
  before you leave
• Hot plates
• Can cause sever burns
• Keep flammables away from the hot plates
• Chemical bench use rules
• Do not use until properly trained

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Whats 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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Whats 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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Electrical Concerns

• Do not operate equipment with cover panels
  removed
• Do not operate equipment with frayed wires
• For example
• E-beam evaporator--10,000 volts
• Plasma etchers--high power RF
• Most equipment runs on 208 volts 60 amps
• It only takes 0.1 amps to kill you!

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The Bottom Line on Safety

• Safety is everyones 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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IVStorage and Disposal of Chemicals

• Label all individual containers
• Change label quarterly
• Place old chemicals on storage cart

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User Chemical Storage

• Chemicals
• Photoresist
• Polymers
• No acids/bases
• Store them in the appropriate cabinets

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Chemical Waste

• Acids and Bases
• Pour down the drain with running city (gray tap)
  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 water, pour down the drain and
  dispose of the bottle
• Empty solvent bottles (one gallon bottles)
• Leave the empty bottle in the hood with the cap
  off
• Staff will dispose of the bottle
• Refill the squirt bottlesdo no throw away

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Waste Containers

• Place all used/waste chemicals on the chemical
  cart
• Do not pour plating solutions down the drain
• Place them on the waste chemical cart

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VAccidents/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
• Cleanroom entrance
• Center cleanroom isle
• Dial x42500 (404-894-2500) Georgia Tech Police
• Add this number to your mobile phone
• State the nature of the emergency
• Do not dial 911they will not know where you are

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Emergency Response Equipment

• Spill response kits
• Located in the chase between the Class 1000 and
  Class 10 photobays
• 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 personyouclean it if you can
• MiRC staff
• GA Tech Environmental Health and Safety
• HAZMAT
• Importantreport all spills
• Call GTPD after hoursas well as MiRC staff

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Toxic Gas Alarms

• Located on the cleanroom walls
• Sensors located near the gas source
• Plasma etchers
• Plasma Deposition
• Gas cabinets
• If the alarm goes off, evacuate immediately

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Toxic Gases UsedPartial Listing

• Phosphine
• Silane
• Chlorine
• Boron Trichloride
• Silicon Tetrachloride
• 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!
• Buddiesmake 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 injuriesother than chemical
  exposuresrequire attention commensurate 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

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Cleanroom Evacuation Routes
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Evacuation Procedure

• Leave the cleanroom immediatelydo not de-gown
• Gather at the front of the Pettit Building on
  Atlantic Drive
• Remove your gown outside