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MiRC Cleanroom Operations. Microelectronics Research Center Georgia Institute of Technology. Chemical Safety Training. Please. Silence your mobile phones for this lecture Wait until a break before answering calls. Agenda. Terminology Cleanroom hazards Safety Practices
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MiRC Cleanroom Operations Microelectronics Research CenterGeorgia Institute of Technology Chemical Safety Training
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 • A MSDS is a document that 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 • Include a MSDS with the first shipment of that chemical
II—Cleanroom 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 • Sharps—razor blades, broken wafers
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 tools—etch and deposition systems
Specific Chemical Hazards • Hydrofluoric Acid • Acetone and Flammable Solvents • Chlorinated Solvents
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 treatment—tubes 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.
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
III—Safety Practices • Gas safety • Chemical usage • Safe chemical practices • Proper (improper) methods • User chemical storage • Personal protective equipment—PPE • Buddy system
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
Chemical Usage • Chemical practice • Labware • Chemical storage • Chemical supplies
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
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
Personal (Personnel) Safety • Personal Protective Equipment • Buddy System • Contact Lenses
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
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 • Irresponsible people endanger everyone • Report unsafe practices to the cleanroom staff • 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
Wet Sinks/Fume Hoods • Chemical bench operation • The hoods are shared equipment—wipe 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
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? • Do not lean into the hood • You expose yourself to harmful fumes • Stay behind the sash • (The plastic screen)
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!
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
Burdell,George Drybox B13 george.burdell@mirc.gatech.eduPI: Rose, Bob IV—Storage and Disposal of Chemicals • Label all individual containers • Change label quarterly • Place old chemicals on storage cart
User Chemical Storage • Chemicals • Photoresist • Polymers • No acids/bases • Store them in the appropriate cabinets
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
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 bottles—do no throw away
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
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 • 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 911—they will not know where you are
Emergency Response Equipment • Spill response kits • Located in the chase between the Class 1000 and Class 10 photobays • 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 • Plasma etchers • Plasma Deposition • Gas cabinets • If the alarm goes off, evacuate immediately
Toxic Gases Used—Partial Listing • Phosphine • Silane • Chlorine • Boron Trichloride • Silicon Tetrachloride • 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 commensurate 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
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