ITO Cleaning
Standard Operating Procedure
Date
Author
14-Feb-2013
Dr Samuele Lilliu
Short
Description
Cleaning of 2 x 1.5 cm glass substrates coated with a thin layer of indium thin
oxide (ITO).
1 Material Requirements
1.1 Equipment needed for process:
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Fume hood equipped with tap water and nitrogen stream;
Fisher Scientific ultrasonic bath with embedded water heater;
2 x 1.5 cm glass substrates;
Nitrile gloves;
Clean room wipes;
2 Tweezers;
5 small 300 mL circular beakers;
safety labelled bottles filled with: acetone, isopropanol, DI water, 1:10 Hellmanex III:
DI water;
Samples cleaning rack;
Small chemical safe plastic container;
Plastic container for the storage of wipes, tweezers, and beakers in the cleanroom;
Small sharp waste container.
1.2 Chemicals needed for process:
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Acetone;
Isopropanol;
DI water;
1:10 Hellmanex III: DI water;
1.3 Hazards associated with chemicals:
1.3.1
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Acetone
Potential Acute Health Effects: Hazardous in case of skin contact (irritant), of eye
contact (irritant), of ingestion, of inhalation. Slightly hazardous in case of skin contact
(permeator).
Potential Chronic Health Effects: CARCINOGENIC EFFECTS: A4 (Not classifiable for
human or animal.) by ACGIH. MUTAGENIC EFFECTS: Not available. TERATOGENIC
EFFECTS: Not available. DEVELOPMENTAL TOXICITY: Classified Reproductive
system/toxin/female, Reproductive system/toxin/male [SUSPECTED]. The substance is
toxic to central nervous system (CNS). The substance may be toxic to kidneys, the
reproductive system, liver, skin. Repeated or prolonged exposure to the substance can
produce target organs damage
1.3.2
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Isopropanol
Potential Acute Health Effects: Hazardous in case of eye contact (irritant), of ingestion,
of inhalation. Slightly hazardous in case of skin contact (irritant, sensitizer, permeator).
Potential Chronic Health Effects: Slightly hazardous in case of skin contact (sensitizer).
CARCINOGENIC EFFECTS: A4 (Not classifiable for human or animal.) by ACGIH, 3 (Not
classifiable for human.) by IARC. MUTAGENIC EFFECTS: Not available. TERATOGENIC
EFFECTS: Not available. DEVELOPMENTAL TOXICITY: Classified Reproductive
system/toxin/female, Development toxin [POSSIBLE]. The substance may be toxic to
kidneys, liver, skin, central nervous system (CNS). Repeated or prolonged exposure to
the substance can produce target organs damage.
1.3.3 (non-diluted) HellManex III
NOTE: in this SOP Hellmanex III is only used in a 1:10 dilution with DI water.
Irritating to eyes and skin. Classification : Xi ; R 36/38
Hazardous components:
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TRIPOTASSIUM ORTHOPHOSPHATE ; EC-No. : 231-907-1; CAS-No. : 7778-53-2.
o Percentage : 15 - 30 %;
o Classification : Xi ; R 36/38;
1.4 Engineering controls
Perform the procedure inside a fume hood.
1.5 Protective Equipment needed
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Cleanroom suit;
Protective goggles;
Nitrile gloves.
1.6 Procedure
Ossila Ltd's pre-patterned device substrates are made from the same ITO covered glass panels used
in the display industry to ensure that the ITO is of extremely high quality and defect free. To
preserve the quality of the ITO surface during shipping and storage it is shipped in clean-room paper.
This means that a simple cleaning routine can be used to provide a pristine ITO surface without the
need for plasma ashing of the substrate.
The first step is to load the substrates into the cleaning rack such that they all have the same
orientation. To identify the ITO side simply look at the edge of the substrate at an oblique angle - the
ITO should be seen to go all the way to the edge when facing towards the viewer.
The loaded substrate rack is then placed in a beaker and submerged in a 10% solution of Hellmanex
III in DI water. The ultrasonic bath is filled with hot water. The substrates are sonicated for five
minutes. After sonication the substrates should be thoroughly rinsed with DI water.
Repeat the same procedure with acetone and isopropanol.
Finally keep the samples immersed in water until ready to blow dry to avoid contamination by dust.
When blow drying, always hold the substrates down at the edge on the cathode side and blow the
nitrogen towards the tweezers so that any dirt on the tweezers is blown off the substrate rather
than onto the active area.
1.7 Storage
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Store Acetone and Isopropanol safety labelled bottles in the appropriate solvents cabinet
under the fume hood.
Store DI water and Hellmanex:DI Water (1:10) safety labelled bottles in the user container.
Store beakers, tweezers and other tools inside user container.
1.8 Waste Products
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Acetone, Isopropanol and 1:10 Hellmanex III: DI water must be disposed in the appropriate
waste bottles for Acetone and Isopropanol.
Dispose broken glass substrates in the sharp waste.
1.9 Accident Procedures
1.9.1
Acetone
Contact
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Eye Contact: Check for and remove any contact lenses. Immediately flush eyes with
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running water for at least 15 minutes, keeping eyelids open. Cold water may be used.
Get medical attention.
Skin Contact: In case of contact, immediately flush skin with plenty of water. Cover the
irritated skin with an emollient. Remove contaminated clothing and shoes. Cold water
may be used.Wash clothing before reuse. Thoroughly clean shoes before reuse. Get
medical attention.
Serious Skin Contact: Wash with a disinfectant soap and cover the contaminated skin
with an anti-bacterial cream. Seek medical attention.
Inhalation: If inhaled, remove to fresh air. If not breathing, give artificial respiration. If
breathing is difficult, give oxygen. Get medical attention if symptoms appear.
Serious Inhalation: Evacuate the victim to a safe area as soon as possible. Loosen tight
clothing such as a collar, tie, belt or waistband. If breathing is difficult, administer
oxygen. If the victim is not breathing, perform mouth-to-mouth resuscitation. Seek
medical attention.
Ingestion: Do NOT induce vomiting unless directed to do so by medical personnel. Never
give anything by mouth to an unconscious person. Loosen tight clothing such as a collar,
tie, belt or waistband. Get medical attention if symptoms appear.
Serious Ingestion: Not available.
Spill or Leak
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Small Spill: Dilute with water and mop up, or absorb with an inert dry material and place
in an appropriate waste disposal container.
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Large Spill: Flammable liquid. Keep away from heat. Keep away from sources of ignition.
Stop leak if without risk. Absorb with DRY earth, sand or other non-combustible
material. Do not touch spilled material. Prevent entry into sewers, basements or
confined areas; dike if needed. Be careful that the product is not present at a
concentration level above TLV. Check TLV on the MSDS and with local authorities.
Fire
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Flammability of the Product: Flammable.
Auto-Ignition Temperature: 465°C (869°F)
Flash Points: CLOSED CUP: -20°C (-4°F). OPEN CUP: -9°C (15.8°F) (Cleveland).
Flammable Limits: LOWER: 2.6% UPPER: 12.8%
Products of Combustion: These products are carbon oxides (CO, CO2).
Fire Hazards in Presence of Various Substances: Highly flammable in presence of open
flames and sparks, of heat.
Explosion Hazards in Presence of Various Substances: Risks of explosion of the product
in presence of mechanical impact: Not available. Slightly explosive in presence of open
flames and sparks, of oxidizing materials, of acids.
Fire Fighting Media and Instructions: Flammable liquid, soluble or dispersed in water.
SMALL FIRE: Use DRY chemical powder. LARGE FIRE: Use alcohol foam, water spray or
fog.
Special Remarks on Fire Hazards: Vapor may travel considerable distance to source of
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1.9.2
ignition and flash back.
Special Remarks on Explosion Hazards: Forms explosive mixtures with hydrogen
peroxide, acetic acid, nitric acid, nitric acid + sulfuric acid, chromic anydride, chromyl
chloride, nitrosyl chloride, hexachloromelamine, nitrosyl perchlorate, nitryl perchlorate,
permonosulfuric acid, thiodiglycol +hydrogen peroxide, potassium ter-butoxide, sulfur
dichloride, 1-methyl-1,3-butadiene, bromoform, carbon, air, chloroform,
thitriazylperchlorate.
Isopropanol
Contact
See Acetone
Spill or Leak
See Acetone
Fire
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Flammability of the Product: Flammable.
Auto-Ignition Temperature: 399°C (750.2°F)
Flash Points: CLOSED CUP: 11.667°C (53°F) - 12.778 deg. C (55 deg. F) (TAG)
Flammable Limits: LOWER: 2% UPPER: 12.7%
Products of Combustion: These products are carbon oxides (CO, CO2).
Fire Hazards in Presence of Various Substances: Highly flammable in presence of open
flames and sparks, of heat. Flammable in presence of oxidizing materials. Nonflammable
in presence of shocks.
Explosion Hazards in Presence of Various Substances: Risks of explosion of the product
in presence of mechanical impact: Not available. Explosive in presence of open flames
and sparks, of heat.
Fire Fighting Media and Instructions: Flammable liquid, soluble or dispersed in water.
SMALL FIRE: Use DRY chemical powder. LARGE FIRE: Use alcohol foam, water spray or
fog.
Special Remarks on Fire Hazards: Vapor may travel considerable distance to source of
ignition and flash back. CAUTION: MAY BURN WITH NEAR INVISIBLE FLAME. Hydrogen
peroxide sharply reduces the autoignition temperature of Isopropyl alcohol. After a
delay, Isopropyl alcohol ignites on contact with dioxgenyl tetrafluorborate, chromium
trioxide, and potassium tert-butoxide. When heated to decomposition it emits acrid
smoke and fumes.
Special Remarks on Explosion Hazards: Secondary alcohols are readily autooxidized in
contact with oxygen or air, forming ketones and hydrogen peroxide. It can become
potentially explosive. It reacts with oxygen to form dangerously unstable peroxides
which can concentrate and explode during distillation or evaporation. The presence of 2butanone increases the reaction rate for peroxide formation. Explosive in the form of
vapor when exposed to heat or flame. May form explosive mixtures with air. Isopropyl
alcohol +phosgene forms isopropyl chloroformate and hydrogen chloride. In the
presence of iron salts, thermal decompositon can occur, which in some cases can
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become explosive. A homogeneous mixture of concentrated peroxides + isopropyl
alcohol are
capable of detonation by shock or heat. Barium perchlorate + isopropyl alcohol gives the
highly explosive alkyl perchlorates.
1.9.3 (non-diluted) HellManex III
NOTE: in this SOP Hellmanex III is only used in a 1:10 dilution with DI water.
Contact
After inhalation: Let in fresh air.
After skin contact: Flush away with water and rinse.
After eye contact: Remove contact lenses, keep eyelids open. Flush with plenty of water (10 - 15
min.). Call a physician.
After ingestion: Drink plenty of water. Call a physician.
Spill or Leak
See Acetone
Fire
Non-inflammable.
Report all accidents (injuries, spills, fires) to fill in the blank For emergencies during non-business
hours, call the Security Control Room at 02 810 9111 or ext 911 from any campus phone or (02)
810 9111 on your cell phone.
PRIOR APPROVAL – This procedure is considered hazardous enough to warrant prior approval from
the Principal Investigator.
YES
NO
Principal Investigator’s
Signature:____________________________________________________________
ADDITIONAL PRECAUTIONS & REFERENCES: