CLEANROOM SAFETY TRAINING ET105

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CLEANROOM SAFETY TRAININGET105 ET107
Peter Miranda Director, Idaho Microfabrication
Laboratory
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Agenda

• General equipment information
• General cleanroom safety rules
• Gowning procedures
• Hazardous chemicals
• Hazardous gases
• Hazardous chemical spill containment
• IML Website

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General Cleanroom

• Class 1000 clean room
• - lt 1000 particles greater than 0.5µm in size for
  a given cubic foot of air.

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Cleanroom Equipment Capabilities

• Thin Film metrology
• Ellipsometer
• Nanospec
• Four point probe
• Optical profilometer
• Dry Etch
• Bosch etcher - DRIE
• Plasma Asher
• Ion Mill coming soon!
• Chemical-Mechanical Polisher
• Wire Bonder
• Rapid Thermal Processor
• Various high powered microscopes
• Single wafer cleaner

• Materials Science Research
• Scanning Electron Microscopes (SEM)
• Thermoionic
• Electron Backscatter Defraction (EBSD)
• Energy Dispersive Spectroscopy (EDS)
• Field Emmision NEW!
• IC Processing
• Oxide/Diffusion Furnace
• Photolithography
• Spin coater
• Contact aligner
• Wet bench processing
• Thin Film Deposition
• PVD
• Thermal Evaporator
• Magnetron Sputter - 2 tools

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General Cleanroom Safety Rules

• Rules and Guidelines for Personal Lab Behavior
• Drinking, eating and gum-chewing are not allowed
  in any part of the lab.
• Full cleanroom attire must always be worn while
  in the cleanroom.
• Be discrete in coughing, sneezing, or blowing
  your nose. At the very least, turn away from the
  processing area and change your gloves before
  commencing processing.
• Minimize the amount of materials stored in the
  lab. All personal items must be labeled with your
  full name, and contact phone number.
• Acceptable Materials in the Cleanroom
• Cleanroom notebooks and cleanroom paper
• Wafers and tweezers (put away when not in use).
• Pens (preferably ball-point).
• Materials with smooth, hard surfaces which can be
  cleaned with alcohol wipes.
• The following materials are not considered
  cleanroom-compatible
• Wood pulp-based paper products, which includes
  regular paper, tissues, cardboard, books, and
  magazines.
• Styrofoam products.
• Any powders.
• Erasers, pencils, felt-tipped pens (other than
  Sharpie markers).
• Anything that can easily shred or aerosolizes
  i.e., anything that may serve as a source of
  particles.

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General Cleanroom Safety Rules

• Never work alone in cleanroom when working on the
  wet bench. Use the buddy system.
• Unlabeled chemicals are significant environmental
  and health hazards. When you make up a solution,
  remember to label it. When labeling a solution,
  you should include the following
• Name of the material contained
• Primary hazard of the material
• Person responsible for the material
• Date of filling or preparation
• If your name, the substance, and a date are not
  present on any chemicals left out on the counters
  (specifically those in glassware), the chemicals
  will be disposed of. If any chemicals need to be
  left out on the counters for longer than 48
  hours, the label should include the date prepared
  and the date the solution will be cleaned up. Be
  courteous and clean up you own chemicals in
  reasonable time frames.
• Leaving the lab
• Clean up after yourself. Leave stations neat and
  ready for the next person to use. Remove personal
  items from general-use areas after you are done
  processing. Label your work.
• Any materials you plan on taking out of the lab
  with you should be bagged to prevent
  contamination.
• In the gowning room remove your bunnysuit from
  the bottom up
• Booties - Put booties in the appropriate bin.
• Suit - Keep the sleeves, main body, and as much
  of the suit as possible off the floor.

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General Cleanroom Safety Rules
Exits

• No shorts or open toed shoes in ET105 or ET107.
• No shorts or skirts allowed in labs.
• Know your safety exits.
• Turn off the lights if you are the last one out.
• Report any safety concerns to the IML director.

Fire Extinguisher
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Cleanroom Gowning Procedures

• Cleanroom bunnysuits are intended to keep the
  cleanroom clean, not the wearer safe. They do
  provide an extra layer of protection that may
  protect against minor spills and splashes,
  however, when using dangerous materials, a
  plastic or rubber apron should be used.
• Do not enter gowning room with dirty shoes ie.
  mud, sand, etc.
• Put on hood (all facial hair must be covered with
  hood, mask, etc.)
• Put on bunny suit
• Put on shoe covers
• Put on gloves, safety glasses
• Blue (Nitrile) gloves are used ONLY for
  non-chemical operations
• Typical uses include working on vacuum systems,
  protecting substrates from contamination,
  operating microscopes, operating equipment.
• Because these gloves don't get contaminated with
  chemicals, you are permitted to operated door
  handles and lab equipment with these gloves.
• Yellow (Latex) gloves are to be used for all
  chemical operations.
• Latex gloves do NOT protect against all chemicals
  so additional gloves might need to be worn over
  the latex gloves for protection.
• Typical chemical operations are mixing acid
  solutions (except HF), using KOH, using etchants,
  using organic solvents or chemicals, etc.
• NEVER operate door handles or equipment while
  wearing yellow gloves. Residual chemicals on the
  gloves can contaminate surfaces and cause serious
  injury to future users.
• Sign-in to cleanroom logbook
• Place single-use gowning gear in hamper, if you
  are a frequent user of the IML, you can hang up
  your gear for the next time. A storage rack is
  located in the clean gowning are to enable
  limited (10 uses, or until shoe covers show
  particles) re-use for economic reasons.

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GENERAL EQUIPMENT SAFETY
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General Equipment Safety

• Dangerous Light Sources Plasma, Ultraviolet
  lamps
• UV Source on Mask Aligners, Pattern Generators
• Light from an Ar plasma in sputter deposition and
  ion etch tools
• Thermal Evaporator
• Smocks, gloves, face mask, eyewear.
• Wipe down all working surfaces when your done
  working on tool.
• Wet Bench Processing Hazardous chemicals!
• Clean up area when you are done.
• Never leave unlabeled chemicals laying around.
• Wear chemical apron, face shield, gloves in
  addition to bunnysuit.
• SEM
• Moving parts - pinch points
• Dry Etch
• Plasma, N2 asphyxiation
• CMP
• Smock, gloves, eyewear
• Moving parts pinch points

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HAZARDOUS CHEMICALS
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Cleanroom Hazardous ChemicalsAcids

• Are typically soluble in water.
• Are corrosive.
• Form salts when mixed with bases.
• Turn litmus paper red. Litmus paper located
  above wet bench and inside toolbox.
• Burn organic tissues and/or inorganic materials.

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Cleanroom Hazardous ChemicalsAcids

• Acetic - CH3COOH
• Liquid and vapors cause severe burns to skin.
  Reacts vigorously with oxidizing agents and other
  acids (particularly nitric). Odor similar to that
  of strong vinegar. Incompatible with most other
  acids. Store alone!
• Chromic - H2CRO4
• Liquid and vapors cause severe burns to skin.
  Corrosive to nasal passages. Contains a suspected
  carcinogen.
• Hydrochloric - HCL
• Highly corrosive to skin and mucous membranes.
  Repeated exposure causes erosion of teeth.
• Hydrofluoric - HF
• Liquid and vapors cause burns that may not be
  immediately painful or visible. HF attacks glass.
  HF looks like water and can kill in small
  amounts. Found in Buffered Oxide Etch (BOE). Use
  only in plastic containers.
• Nitric - HNO3
• Highly corrosive to skin, mucous membranes and
  teeth. Highly reactive with acetic acid. Reacts
  explosively with combustible organic or other
  oxidizers. Use only in glass containers.
• Phosphoric - H3PO4
• Liquid is highly irritating to skin. Vapors are
  highly toxic. Contact with most metals causes
  formation of flammable and explosive hydrogen
  gas.
• Sulfuric - H2SO4
• Liquid and vapors are extremely corrosive to skin
  and mucous membranes. Generates heat upon contact
  with water. Reacts with acetic acid. Keep away
  from water.
• Citric - C6H8O7
• Skin and eye irritation

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Special Precaution on HF

• Hydrofluoric Acid
• Hydrofluoric acid (HF) is EXTREMELY dangerous. Be
  extra attentive when working with HF. HF is
  colorless and odorless it looks and smells like
  water. HF is an ingredient in many oxide etches
  which are used to etch glass. Because of the
  danger, only trained personnel should pour HF.
  According to DuPonts MSDS.
• HF will
• Penetrate skin.
• Attack (decalcify) bones.
• React with your bodys chemicals to make
  poisonous salts.
• HF may
• Kill if more than 5 of the body is exposed.
• Kill if ingested or inhaled.
• Depending on concentration, not cause pain for up
  to 24 hours after contact.
• Some of the symptoms of HF exposure are
• Itching.
• Red or white discoloration of the skin.
• Pain within 24 hours after contact.
• Discoloration under fingernails or toenails.
• Treatment with Calcium Gluconate Gel
• Calcium gluconate gel is a topical antidote for
  HF skin exposure. Calcium gluconate works by
  combining with HF to form insoluble calcium
  fluoride, thus preventing the extraction of
  calcium from tissues and bones. Keep calcium
  gluconate gel nearby whenever youre working with
  HF. Calcium gluconate can be ordered through Life
  Safety Associates www.lifesafety.com. Calcium
  gluconate  has a limited shelf life and should be
  stored in a refrigerator if possible and replaced
  with a fresh supply after its expiration date has
  passed. Use disposable gloves to apply calcium
  gluconate gel. Even after applying calcium
  gluconate, it is essential that a medical
  evaluation be made.

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Cleanroom Hazardous ChemicalsAcids Waste
Disposal

• Acids (including piranha), must be aspirated from
  their containers. An aspirator has a Teflon tube
  through which it sucks a liquid from a container.
  Our Microfab wet bench has an aspirator. The
  fresh water plenum flush is automatically
  activated when an aspirator is turned on. The
  plenum flush adds water to aspirated waste,
  further diluting it. NEVER POUR ACIDS, BASES
  directly down a drain Always use the aspirator.
  Never mix solvents with acids when aspirating
  This is a potentially explosive combination! And
  remember AAA-always add acid to water!

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Cleanroom Hazardous ChemicalsBases

• Are typically water soluble.
• Are slippery.
• Taste bitter.
• Form salts when mixed with acids.
• Turn litmus paper blue.
• Are corrosive.
• Burn organic tissues.

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Cleanroom Hazardous ChemicalsBases

• Ammonium Hydroxide - NH4OH
• Irritating to skin and mucous membranes. Emits
  highly toxic vapors when heated.
• Potassium Hydroxide - KOH
• Sodium Hydroxide NaOH
• Photoresist developers

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Cleanroom Hazardous ChemicalsBases Waste
Disposal

• Aspirate chemical waste same as acids.

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Cleanroom Hazardous ChemicalsSolvents

• A solvent is a chemical substance which dissolves
  another substance. The most common solvent is
  water.
• Solvents are used extensively in the electronics
  industry. Compounds such as Isopropyl Alcohol
  (IPA) and acetone are used to clean and dry
  wafers, glassware, equipment, and most working
  surfaces in the lab. In addition, solvents are
  the principle components of many process
  chemicals such as photoresist.
• Organic solvents react chemically with acids,
  producing a violent reaction. As a by-product of
  the chemical reaction, gases are released, as
  well as a great amount of heat. Therefore, acids
  and solvents and their vapors should never come
  into contact with one another.
• Organic solvents should never come in contact
  with oxidizers such as hydrogen peroxide and
  chromic etch. Oxidizers are a class of their own
  and will also react violently with organic
  solvents and acids.
• Major solvents and their abbreviations used in
  the IML
• Acetone - ACE
• Isopropyl Alcohol - IPA
• Propylene Glycol Monomethyl Ether Acetate - PGMEA

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Cleanroom Hazardous ChemicalsSolvents

• Acetone-ACE
• Irritates eyes, nose and throat headaches skin
  dryness
• Isopropyl Alcohol-IPA
• Dries skin irritates eyes, nose and throat
  drowsiness
• Methyl Isobutylketone-MIBK
• Irritates eyes, nose and throat may cause
  weakness, dizziness, lightheadedness, nausea,
  vomiting, or kidney damage.
• Propylene Glycol Monomethyl Ether Acetate-PGMEA
• Irritant may cause itching, redness and burns to
  skin ingestion may cause diarrhea, kidney and
  liver damage
• Ethyl Lactate-Positive Photo Resist
• Combustible liquid skin, eye, respiratory
  irritant nervous system toxin

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Cleanroom Hazardous ChemicalsSolvents Waste
Disposal

• Organic solvents such as chlorobenzene or TCA
  (trichloroethane) and photoresist, should never
  be aspirated or poured down the drain. Solvents
  must be poured into solvent disposal bottles.
  Never pour acid for disposal into a solvent
  waster bottle because an explosion may result.
  Make sure chemical disposal bottles are not
  overfilled. When a chemical disposal bottle is
  approximately 75 full
• Loosely cap the bottle. DO NOT TIGHTEN THE CAP.
  This prevents accidental pressure buildup from
  breaking the bottle.
• Remove the label from the chemical disposal
  bottle. Enter the summary of contents to the
  peel-off label and place on the bottle.
• Chemicals for disposal placed in the Waste
  Chemical Cabinet must be labeled with contents
  and the name of the lab member. Placing
  unlabeled chemicals for disposal in this cabinet
  is a violation of lab policy, which may result in
  suspension from the Microfab. You must fill out
  the Chemical Disposal Manifest Sheet located on
  top of the disposal cabinet. The bottles are
  picked up by the BSU Environment, Health and
  Safety Department. Notify the Microfab office if
  the storage area is full.
• Use a safety carrier if the bottle is glass.
  Rinse bottles thoroughly 3 times under the
  fumehood. This will prevent exposure to volatile
  compounds while rinsing bottles. Wear a face
  shield and chemical resistant gloves while doing
  so. Once the bottle has been rinsed 3 times,
  black out the label with a marker. The scratched
  label indicates that the bottle has been properly
  rinsed.
• Collected in containers for pick up by
  Environmental Safety Services. Small incidental
  quantities should be rinsed down the drain with
  copious amounts of water. For questions about
  waste solvents, contact the lab manager. Do not
  dump solvents down the drains.
• It is very important to clean up solvent spills
  in order to minimize the fire hazard and the
  amount of vapors present in the lab. If you find
  a spill and can not identify it, contact the lab
  manager. The spilled chemical needs to be
  identified before it can be cleaned up.

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ACCIDENTAL SPILL CONTAINMENT
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Chemical Spill Clean-up

• Small chemical spill (4L or less)
• Test spill pH with litmus paper if chemical is
  unknown before proceeding.
• Clean up spill with chemical spill pillows or
  blankets.
• Spill pillows blankets are designed to be very
  absorbent and neutralize acid spills.
• Dispose of waste in appropriate bin.
• Large chemical spill
• New policy CALL 911!
• Notify lab manager at once!
• Leave lab immediately.
• For VERY large chemical spills, pull emergency
  fire alarm on your way out the door.
• Use your best judgment if the spill is going to
  put anyone else in the room and/or building in
  danger, act accordingly.

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What to do when you notice or smell trouble in
the cleanroom

• If there is a strong chemical odor coming from
  the cleanroom
• Do.
• Dial 911 first then contact the cleanroom manager
  and others on the emergency contact list.
• exit the cleanroom and post a DO NOT ENTER sign
  on the door.
• Do Not.
• Enter the cleanroom in a attempt to determine
  what the source of the odor is.
• Try and clean-up the spill.
• If there is a large amount of unidentified liquid
  on the cleanroom floor
• Do
• Call 911!
• Contact the cleanroom manager and others on the
  emergency contact list.
• Do Not..
• Enter the cleanroom in an attempt to locate the
  source of the liquid.
• Try and cleanup the spill.

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HAZARDOUS GASES
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Cleanroom Process Gases

• Cylinders of both toxic and non-toxic
  compressed gases are in use throughout the lab.
• Only well trained students or staff may not
  install or disconnect these cylinders.
• Some gases in these cylinders are at high
  pressures (1500psi).
• Improper installation or purging will contaminate
  a full bottle of gas. Some of our etching gases
  cost hundreds of dollars and their loss or
  contamination is very costly.
• Gas cylinders must be chained and strapped down at
   all times.
• Precautions
• The large volume of gas produced from evaporation
  of a liquid can displace sufficient oxygen in a
  closed room to be dangerous (nitrogen
  asphyxiation). Ensure you have adequate
  ventilation for any operation consuming or
  transferring liquid nitrogen or helium.

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Cleanroom Hazardous GasesCompressed Gases

• Handle cylinders of compressed gases as
  high-energy sources and therefore as potential
  explosives.
• Cylinders must not be dragged or rolled.
  Cylinders should not lean on one another.
• Restrain cylinders of all sizes, empty or full,
  individually by straps, chains, or a suitable
  stand to prevent them from falling.
• Do not expose cylinders to temperatures higher
  than approximately 50C. Some small cylinders,
  such as lecture bottles, are not fitted with
  rupture devices and may explode if exposed to
  high temperatures.
• Cylinders should be stored in appropriately
  ventilated closets or in an open storage area.
  Store gases according to chemical compatibility .
  
• Never store a cylinder next to a heat or flame
  source.
• Do not place gas cylinders such that there is
  contact with electrical circuitry.
• Never use cylinders that cannot be identified
  positively.
• Inspect cylinder valves for damage or corrosion
  prior to use. If unsuitable for use, return to
  supplier
• Never lubricate or modify the cylinder valves.
• Do not put oil or grease on the high pressure
  side of any oxygen, chlorine or other oxidizing
  agent cylinder valve. A fire or explosion can
  result
• Use the appropriate regulator on each gas
  cylinder. The threads on the regulators are
  designed to avoid improper use. Do not use any
  adapter between the gas cylinder and the
  regulator.

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Cleanroom Hazardous GasesCompressed Gases

• Use toxic, flammable, corrosive, or reactive
  gases in fume hoods only. Post signs in the
  laboratory area when using any of these type
  gases.
• Never bleed cylinders completely empty. Leave a
  slightly positive pressure (30 psi) to keep
  contaminants out. (Never heat a compressed gas
  cylinder to "milk" out the last bit of gas. The
  base plug softens and it becomes a missile.)
• Remove the regulator from an empty cylinder and
  replace the protective cap. Mark the cylinder
  "empty" and place it in the appropriate location
  for pickup. Notify Microfab Staff.
• Do not mix gases within a cylinder. If a mixture
  is required, order it that way from the supplier.
  
• Never open a cylinder more than 1/2 to 3/4 of 1
  turn. This way the cylinder can be turned off
  quickly in the event of an emergency.
• Review the MSDS sheets for the gasses that you
  are using. Many of the gasses are toxic. All high
  pressure gasses, regardless of toxicity, should
  be treated with respect.
• Before using any gas on any piece of equipment,
  verify that the gas that you think is connected
  is the one that actually is connected.
• Always wear safety glasses when handling
  compressed gases.
• Make sure all cylinders are properly labeled.
• Never direct high pressure gases at a person
• Regulators, gauges, and hoses should not be
  interchanged among gases.
• Do not place any item on top of a cylinder that
  could damage a safety device or interfere with
  quick closing of a valve.

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Cleanroom Information Tools

• IML Website
• http//coen.boisestate.edu/IMFL/index.html
• designed to be used as a reference guide for
  cleanroom operations.
• Safety procedures coming soon!
• Equipment operating procedures
• General semiconductor processes - WIP
• Chemical inventory
• Cleanroom chemical data sheets
• Lab manual coming soon!
• Comprehensive manual for cleanroom users.

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Emergency Contacts

• Peter Miranda, Lab Director x65713 or 447-6636
• Rex Oxford, interim COEN Facilities Manager,
  x65744
• Dr. Amy Moll, COEN/MSE Faculty x65719
• Dr. Bill Knowlton, COEN/MSE Faculty x65705
• Jim Stevenson, Staff Engineer x65757
• Cal Gillis, BSU Environmental Health Officer,
  x63999
• All MAJOR spills must be reported to the Boise
  Department of Public Works.
• Boise Department of Public Works Contact List
• Walt Baumgartner, Senior Environmental Specialist
  343-3991
• Mike Hunter, Pretreatment Program Director
  384-3993

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THE END