NMDC Cleanroom Operations
Nano and Micro Device Center ( NMDC )
University of Alabama in Huntsville
Part of content is borrowed from the website information of
Georgia Tech MiRC, and UC Berkeley Microlab.
ChemicalNano
Safety
Training
and Micro Device Center (NMDC) UAH
NMDC Contact List
• NMDC Staff
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Director: Dr. R. Lindquist
Associate Director: Dr. J. D. Williams
Research staff: Dr. Yongbin Lin
Process Engineer: Frank Berisford
Operational support: Rozella Coggin
400 Optics Building
406 Optics Building
438 Optics Building
103 Optics Building
412 Optics Building
(256) 824 -2882
(256) 824 -2898
(256) 824 (256) 824 -2981
(256) 824 -2907
• Other Emergency Contacts
– Campus Police
– Campus Chemical Safety
– Facilities Services
400 Optics Building (256) 824 -2882
406 Optics Building (256) 824 -2898
See an NMDC Staff member
Nano and Micro Device Center (NMDC) UAH
Agenda
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General policies
Terminology
Cleanroom hazards
Safety Practices
Storage and disposal of chemicals
Accidents and emergencies
Nano and Micro Device Center (NMDC) UAH
POLICIES AND PROCEDURES HIGHLIGHTS (1)
• Everyone must sign in/out in the log.
• REQUIRED ATTIRE: Hood, gown, booties w/shoe
covers, bouffant caps, gloves, and safety eyewear.
• Keep all hair and ears covered with hood or cap.
• Never open your gown in the cleanroom.
• Never touch your skin with your gloves. If you do,
put on clean gloves immediately.
• Only authorized users may enter the cleanroom
unescorted.
Nano and Micro Device Center (NMDC) UAH
POLICIES AND PROCEDURES HIGHLIGHTS (2)
• Visitors must be escorted by a cleanroom qualified
faculty/staff member.
• No food or drink is permitted in the cleanroom.
• No corrugated cardboard, styrofoam, foam rubber
or non-cleanroom paper is permitted in the
cleanroom.
• No pencil, erasers or retractable pens are permitted
in the cleanroom.
• Be considerate. (Clean up your own mess, don’t
mess up someone else's work, order new supplies if
they are needed.)
Nano and Micro Device Center (NMDC) UAH
POLICIES AND PROCEDURES HIGHLIGHTS (3)
• Ask for permission before bringing anything in or
taking anything out of the cleanroom.
• DO NOT modify equipment without the approval
of the NMDC Staff.
• IF YOU AREN’T SURE HOW IT WORKS, ASK
BEFORE YOU USE IT!
• FOLLOW THE NMDC and UAH LAB SAFETY
GUIDELINES.
• This lab course qualifies you only to enter the lab
and use the computer. Everyone qualifies separately
to use any piece of equipment needed.
Nano and Micro Device Center (NMDC) UAH
POLICIES AND PROCEDURES HIGHLIGHTS (4)
• NMDC requires from each member a
donation of 4 hours to help lab cleaning in
each semester.
• Members learn from each other and, in turn,
teach others.
Nano and Micro Device Center (NMDC) UAH
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
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Chemical Property Terms
Exposure, toxic effects, & exposure levels
Storage & handling
Emergency procedures
Safe disposal & transportation
Nano and Micro Device Center (NMDC) UAH
Sources of Chemical Information
• NMDC cleanroom website
• Vender website
• Manufacturers/suppliers
– Include a MSDS with the first shipment of that
chemical
Nano and Micro Device Center (NMDC) UAH
II—Cleanroom Hazards
• While working in the cleanroom, you will
use various chemicals to process your wafers
and the following (potential) hazards
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Hydrofluoric Acid (HF)
Acids and bases
Solvents
Electrical
Sharps—razor blades, broken wafers
Toxic, flammable, and corrosive gases
Nano and Micro Device Center (NMDC) UAH
Specific Chemical Hazards
• Hydrofluoric Acid
• Acetone and Flammable Solvents
• Chlorinated Solvents
Nano and Micro Device Center (NMDC) UAH
Hydrofluoric Acid (HF) 1
• 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.
Nano and Micro Device Center (NMDC) UAH
Hydrofluoric Acid (HF) 2
• Protective gloves. Even pin-hole leaks through gloves may
result in significant damage to the skin, especially if contact
under the finger nails occurs. If hands are sweaty, leakage
may not even be noticed. Gloves should be dedicated for HF
use only, and should be discarded if any contact with the
acid occurs. They should be inspected prior to use and
changed frequently.
• Glove breakthrough times vary with material, thickness,and
manufacturer. Contact the glove manufacturer or EMS for
information on specific gloves. In general, long gauntlettype nitrile, neoprene, and natural rubber gloves should
provide adequate protection against splashing and during the
clean-up of small hydrofluoric acid spills.
Nano and Micro Device Center (NMDC) UAH
Hydrofluoric Acid (HF) 3
• Eye and Face Protection: Contact lenses may not be
worn when handling HF. Splash-proof chemical
goggles or safety glasses with side shields are
required. In addition, face shields must be worn
during HF use.
• Protective Clothing: A lab coat, in addition to long
gauntlet-type gloves, is the minimum required
protection for the small quantities of HF (i.e., a few
ml) typically handled at the NMDC. Neoprene
aprons with attached sleeves shall be worn while
transferring quantities in excess of 10 ml of HF.
Nano and Micro Device Center (NMDC) UAH
Acetone and Flammable Solvents
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Solvents have a high vapor pressure
These fumes can make breathing difficult
They are extremely flammable
Solvents often cause extreme pain if splashed in the
eye
• Like alcohol (a solvent), they attack the liver
• Extreme care should be used with using solvents at
high temperatures. Improper use may result in fire
or explosions
Nano and Micro Device Center (NMDC) UAH
Chlorinated Solvents
• Chlorinated solvents are very useful and thus often found in
cleanroom environments
• However they are extremely toxic and often flammable
• Use extreme care when processing these chemicals
• Do NOT use these chemicals if you are or think you are
pregnant
• Example: Trichloroethylene
– Extremely useful for cleaning metals and disolving polymers
– Known to cause cancer in humans
– Must be covered at all times during use and placed at the rear of the
hood
– Reacts exothermically and should not be used in conjunction with a
hotplate
Nano and Micro Device Center (NMDC) UAH
III—Safety Practices
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Chemical usage
Safe chemical practices
Proper (improper) methods
User chemical storage
Personal protective equipment—PPE
Buddy system
Nano and Micro Device Center (NMDC) UAH
Chemical Usage
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Chemical practice
NMDC wet benches for chemical use
Establishing your work environment
Proper use of labware
Chemical storage
Chemical supplies
Nano and Micro Device Center (NMDC) UAH
Safe Chemical Practices
• Chemicals are to be used in their appropriate
stations ONLY!
• Be aware of possible chemical reactions
• New chemicals must be approved by NMDC 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
Nano and Micro Device Center (NMDC) UAH
Wet Sinks/Fume Hoods
• Chemical bench operation
– Four benches in the NMDC: Acid, Base, Solvent, RCA clean
– NMDC process benches are labeled for use with their specific
chemical type and/or use. Be sure you are using the proper hood for
the your processes.
– Chemicals used in the NMDC should be clearly labeled at all times
and covered when not in immediate use.
– Chemicals in use may be left unattended if labeled for short periods
of time (30 min or so), however the user is not allowed to leave the
cleanroom without storing or wasting the chemical and cleaning the
appropriate dishware.
– Personal storage of chemicals between uses is allowed in
appropriated sealed containers that are labeled with the users name,
date, and common chemical name.
– The hoods are shared equipment: they should be clean when you
arrive, and wiped down before you leave
Nano and Micro Device Center (NMDC) UAH
Hot Plate use in Wet Sinks/Fume Hoods
• Hot plates
– Can cause sever burns.
• Be sure to turn hot plates off after use.
• If you leave a hotplate unattended for short periods of time
(10min or so) place an “IN USE” sign in front of it to warn
others.
– Keep flammables away from the hot plates.
• The maximum temperature of hotplates in the solvent hood is
50 oC without express permission of the staff.
• The use of Acetone on a hotplate requires specific staff
permission and two people monitoring the process at all times.
Nano and Micro Device Center (NMDC) UAH
Establishing Your Work Environment
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Be sure while working in the NMDC that you are thoughtful and courteous of
others’ needs.
Each person working with chemicals in a hood should use approximately 1/3 of
the bench at any given time
All containers should be clearly labeled PRIOR to use using a erasable marker
with:
– Your Name
– Date
– Chemistry contained
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Labeling can be done on the container or on wipes placed below the container.
The label must be clearly visible and readable at ALL times.
All chemicals should be placed in such a way that allows safe operation without
risk of spillage or inhalation.
Lids should be placed close by so that chemicals covered between uses.
Be sure you are aware of, can get to, and use proper hazardous waste/storage
containers for your chemical operations
Clean as you GO!!! Allot can be said for maintaining a clean working
environment.
Nano and Micro Device Center (NMDC) UAH
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, always use a
plastic container
Nano and Micro Device Center (NMDC) UAH
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
Nano and Micro Device Center (NMDC) UAH
Personal (Personnel) Safety
• Personal Protective Equipment
• Buddy System
• Contact Lenses
Nano and Micro Device Center (NMDC) UAH
Personal Protective Equipment (PPE)
• The following PPE is
required while using
chemical in any hood:
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Eye protection
Gloves
Face shield
Apron
• Your cleanroom
garment is NOT
protective equipment
Nano and Micro Device Center (NMDC) UAH
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
Nano and Micro Device Center (NMDC) UAH
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
Nano and Micro Device Center (NMDC) UAH
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
Nano and Micro Device Center (NMDC) UAH
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)
Nano and Micro Device Center (NMDC) UAH
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!
Nano and Micro Device Center (NMDC) UAH
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
Nano and Micro Device Center (NMDC) UAH
IV—Storage and Disposal of Chemicals
• Label all individual containers
• Change label quarterly
• Place old chemicals on storage cart
Nano and Micro Device Center (NMDC) UAH
User Chemical Storage
• Chemicals
– Photoresist
– Polymers
• No acids/bases
– Store them in the
appropriate cabinets
Nano and Micro Device Center (NMDC) UAH
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
Nano and Micro Device Center (NMDC) UAH
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
Nano and Micro Device Center (NMDC) UAH
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
Nano and Micro Device Center (NMDC) UAH
Gas hazards (partial listing)
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Pyrophoric (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
Nano and Micro Device Center (NMDC) UAH
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
Nano and Micro Device Center (NMDC) UAH
Gas Safety
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Do not cycle any valves
Do not loosen any fittings
Do not disconnect any gas lines
Be aware of alarms or any unusual odors
Nano and Micro Device Center (NMDC) UAH
Toxic Gases Used—Partial Listing
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Phosphine
Silane
Chlorine
Boron Trichloride
Silicon Tetrachloride
Ammonia
Do not take the alarms lightly
Nano and Micro Device Center (NMDC) UAH
V—Accidents/Emergencies
• Emergency Phones
• Emergency Response Equipment
• Chemical Accidents
– Responding to a spill
– Escalation
– Transporting victims
• Toxic Gas Alarms
• Safety Showers
• Evacuation Routes
Nano and Micro Device Center (NMDC) UAH
Emergency Phones
• Emergency phones
– Cleanroom entrance
– Center cleanroom isle
– Dial 6911 for UAH 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
Nano and Micro Device Center (NMDC) UAH
Emergency Response Equipment
• Spill response kits
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Location
Acid neutralizer
Base neutralizer
Absorbent material
Nano and Micro Device Center (NMDC) UAH
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
Nano and Micro Device Center (NMDC) UAH
Escalation
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First person—you—clean it if you can
NMDC staff
UAH Environmental Health and Safety
HAZMAT
Important—report all spills
– Call UAH police after hours—as well as NMDC
staff
Nano and Micro Device Center (NMDC) UAH
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
Nano and Micro Device Center (NMDC) UAH
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
Nano and Micro Device Center (NMDC) UAH
Transporting a Victim
• Minor injuries—other than chemical
exposures—require attention commensurate
with the injury
• All chemical exposures require
hospitalization
Nano and Micro Device Center (NMDC) UAH
Transportation Procedure
• Call UAH police 6911 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
Nano and Micro Device Center (NMDC) UAH
Cleanroom Evacuation Routes
Nano and Micro Device Center (NMDC) UAH
Evacuation Procedure
• Leave the cleanroom immediately—do not
de-gown
• Gather at the front of the Optics Building on
John Wright Drive
• Remove your gown outside
Nano and Micro Device Center (NMDC) UAH