1. CLEANROOM SAFETY TRAINING ET105 & ET107
Peter Miranda
Director, Idaho Microfabrication Laboratory

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

3. General Cleanroom Class 1000 clean room
- < 1000 particles greater than 0.5µm in size for a given cubic foot of air.

4. 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

5. 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.

6. 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.

7. 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

8. 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.

9. GENERAL EQUIPMENT SAFETY

10. 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

11. HAZARDOUS CHEMICALS

12. Cleanroom Hazardous Chemicals Acids
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.

13. Cleanroom Hazardous Chemicals Acids
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

14. 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 DuPont’s MSDS.
HF will:
Penetrate skin.
Attack (decalcify) bones.
React with your body’s 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 you’re working with HF. Calcium gluconate can be ordered through Life Safety Associates 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.

15. Cleanroom Hazardous Chemicals Acids – 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!

16. Cleanroom Hazardous Chemicals Bases
Are typically water soluble.
Are slippery.
Taste bitter.
Form salts when mixed with acids.
Turn litmus paper blue.
Are corrosive.
Burn organic tissues.

17. Cleanroom Hazardous Chemicals Bases
Ammonium Hydroxide - NH4OH
Irritating to skin and mucous membranes. Emits highly toxic vapors when heated.
Potassium Hydroxide - KOH
Sodium Hydroxide – NaOH
Photoresist developers

18. Cleanroom Hazardous Chemicals Bases – Waste Disposal
Aspirate chemical waste same as acids.

19. Cleanroom Hazardous Chemicals Solvents
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

20. Cleanroom Hazardous Chemicals Solvents
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

21. Cleanroom Hazardous Chemicals Solvents – 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.

22. ACCIDENTAL SPILL CONTAINMENT

23. 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.

24. 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.

25. HAZARDOUS GASES

26. 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.

27. Cleanroom Hazardous Gases Compressed 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.

28. Cleanroom Hazardous Gases Compressed 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.

29. Cleanroom Information Tools
IML Website
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.

30. 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
Mike Hunter, Pretreatment Program Director

31. THE END