Chromerge Cleaning Solution
Chemical Standard Operating Procedure
Chromerge cleaning solution can be used to clean organic contaminants from glass,
alumina, and aluminum nitride substrates.
1. Material Requirements:
1.1. Equipment needed need for process:
1.1.1. Standard plastic (Teflon®, Nalgene®, or PTFE) labware jar with tight
1.1.2. Plastic (Teflon®, Nalgene®, or PTFE) wafer holder.
1.2. Chemicals needed for process:
1.2.1. One bottle (25 mL) of Chromerge Concentrated Labware Cleaner (CCLC
from this point forward) (Fisher Scientific Catalog #C577-12), which
contains 50% water and 50% chromic acid by volume (CAS# 7738-94-5).
1.2.2. One bottle (2.5 L) of Sulfuric Acid (CAS# 7664-93-9).
1.3. Hazards associated with all chemicals:
1.3.1. Health Rating (Lewis): Once the two chemicals are mixed together the
hazards of the solution will be different than the individual component
184.108.40.206. CCLC: n/a
220.127.116.11. Sulfuric Acid: 3
1.3.2. Symptoms (MSDS):
18.104.22.168.1. CCLC: irritation with burning pain, and redness.
22.214.171.124.2. Sulfuric Acid: redness, pain, and severe burns.
126.96.36.199.1. CCLC: severe irritation, and possible eye burns.
188.8.131.52.2. Sulfuric Acid: corrosive; may cause blurred vision, redness,
pain, severe tissue burns, and blindness.
184.108.40.206.1. CCLC: irritation of respiratory tract with burning pain in the
nose and throat, coughing, wheezing, shortness of breath, and
220.127.116.11.2. Sulfuric Acid: irritation of the respiratory tract with burning
pain in the nose and throat, labored breathing, and pulmonary
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18.104.22.168.1. CCLC: irritation of the gastrointestinal tract with nausea,
vomiting, and possible burns. May cause liver and kidney
22.214.171.124.2. Sulfuric Acid: severe burning of the mouth, throat, and
stomach leading to death.
126.96.36.199. Chronic exposure:
188.8.131.52.1. CCLC: may cause nosebleeds, nasal congestion, dermatitis
and/or skin ulceration, lung cancer, and gastrointestinal tract
184.108.40.206.2. Sulfuric Acid: long term exposure to vapors or mist may cause
damage to teeth. Cancer hazard.
1.3.3. NFPA Hazard Classification (MSDS):
220.127.116.11.1. CCLC: 0
18.104.22.168.2. Sulfuric Acid: 0
22.214.171.124.1. CCLC: 3
126.96.36.199.2. Sulfuric Acid: 3
188.8.131.52.1. CCLC: 1
184.108.40.206.2. Sulfuric Acid: 3
220.127.116.11. Specific Hazard:
18.104.22.168.1. CCLC: none listed
22.214.171.124.2. Sulfuric Acid: W
1.3.4. Safety Profile (Lewis):
126.96.36.199. CCLC: there is no specific profile listed.
188.8.131.52. Sulfuric Acid: Human poison by unspecified route. Experimental
poison by inhalation. Moderately toxic by ingestion. A severe eye
irritant. Extremely irritating, corrosive and toxic to tissue, resulting
in rapid destruction of tissue causing severe burns. If much skin is
involved, exposure is accompanied by shock, collapse, and symptoms
similar to those of severe burns. Repeated contact with dilute
solutions can cause dermatitis and repeated or prolonged inhalation of
a mist of sulfuric acid can cause inflammation of the upper
respiratory tract, leading to chronic bronchitis. This is a very
powerful acidic oxidizer that can ignite or explode on contact with
many materials. When heated it emits highly toxic fumes; will react
with water or steam to produce heat; can react with oxidizing or
reducing materials. When heated to decomposition it emits toxic
fumes of SOx.
1.3.5. MIOSHA PEL:
184.108.40.206. CCLC: none listed.
220.127.116.11. Sulfuric Acid: TWA is 1 mg/m3.
1.3.6. OSHA PEL (Lewis):
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18.104.22.168. CCLC: none listed
22.214.171.124. Sulfuric Acid: TWA is 1 mg/m3
1.3.7. ACGIH TLV (Lewis):
126.96.36.199. CCLC: TWA is 0.05 mg/m3 (as Cr)
188.8.131.52. Sulfuric Acid: TWA is 1 mg/m3, STEL is 3 ppm
1.4. Engineering controls:
1.4.1. Conducted at the acid bench in the GaAs bay.
1.5. Administrative controls:
1.5.1. No additional controls are needed beyond those implemented in the
chemical hygiene plan (CHP).
1.5.2. Chromerge Cleaning Solution is purchased as a non-premixed solution.
However, it is mixed in the lab in a large quantity (2.5 L) and any unused
but already mixed quantities will be stored in the acid (corrosive) cabinet.
1.6. Protective equipment needed:
1.6.1. Trionic gloves worn over latex gloves, apron, and face shield are required
to be worn while mixing or using Chromerge Cleaning Solution.
2.1. Use of Chromerge Cleaning Solution
2.1.1. Chromerge Cleaning Solution is hydroscopic and will absorb water from
the air. As the solution ages and absorbs more water, it will lose its
effectiveness. The solution should be discarded (see Section 4) when a
greenish tint is visible.
2.1.2. A small “in-use” quantity will be kept in a tight lidded plastic (Teflon ®,
Nalgene®, or PTFE) container in the GaAs bay acid bench. If this solution
is expired (indicated by color change), then properly dispose of waste (see
Section 4), and check the acid cabinet for any mixed Chromerge Cleaning
Solution. If there is no mixed solution, follow Section 2.2 for mixing
2.1.3. Be sure that all wafers and wafer holders are completely dry before being
dipped into the Chromerge Cleaning Solution to maximize the solution
2.1.4. Dip wafers into Chromerge Cleaning Solution and slowly move the wafer
holder in a circular motion.
184.108.40.206. For glass wafers, the recommended cleaning time is 3 minutes.
220.127.116.11. For ceramic wafers, the recommended cleaning time is 2 minutes.
2.1.5. Rinse wafers in the cascade rinse tank until the resistivity of the rinse
water reaches 16 M·cm.
2.2. Mixing Chromerge Cleaning Solution
2.2.1. Pour one entire bottle (25 mL) of CCLC into one entire bottle (2.5 L)
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2.2.2. Place 2.5 L bottle cap back on bottle, and gently shake until all particles
2.2.3. Using black marker, cross out the sulfuric acid label. Fill out proper
chemical label with “Chromerge Cleaning Solution” and “Use Until
Gone,” and affix label to bottle.
2.2.4. Follow proper procedure to dispose of the empty 25 mL bottle of CCLC.
2.2.5. Store any unused quantity of mixed Chromerge Cleaning Solution in the
3.1. Unused Chromerge Cleaning Solution is stored in the acid (corrosive) cabinet.
3.2. Expired (or waste) Chromerge Cleaning Solution is stored in the acid (corrosive)
4. Waste Products:
4.1. Expired Chromerge Cleaning Solution must be poured into a properly labeled
waste bottle. Never pour large quantities of waste down the drain for
4.2. The waste bottle is kept in the acid (corrosive) cabinet. If no waste bottle is
present, one can be made by properly labeling an empty sulfuric bottle (generated
from general lab use). Use the proper waste label found in the general lab supply
rack near the acid/base/oxidizer/solvent storage cabinets.
4.3. Use a funnel when pouring expired solutions into the waste bottle to minimize
the chances of spilling. The funnel can be rinsed in the acid hood sink.
5. Accident Procedures:
18.104.22.168. CLCC: Get medical aid immediately. Immediately flush skin with
plenty of water for at least 15 minutes while removing contaminated
clothing and shoes. Contact staff member immediately.
22.214.171.124. Sulfuric Acid: Immediately flush skin with plenty of water for at
least 15 minutes. Contact staff member immediately.
126.96.36.199. CLCC: Get medical aid immediately. Immediately flush with plenty
of water for at least 15 minutes, occasionally lifting the upper and
lower eyelids. Contact staff member immediately.
188.8.131.52. Sulfuric Acid: Immediately flush with plenty of water for at least 15
minutes, occasionally lifting the upper and lower eyelids. Contact
staff member immediately.
184.108.40.206. CLCC and Sulfuric Acid: Get medical aid immediately. Remove
from exposure and move to fresh air immediately. If not breathing,
give artificial respiration. If breathing difficult, give oxygen. Contact
staff member immediately.
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220.127.116.11. CLCC: Get medical aid immediately. Do NOT induce vomiting. If
conscious and alert, rinse mouth and drink 2-4 cupfuls of milk or
water. Contact staff member immediately.
18.104.22.168. Sulfuric Acid: Do NOT induce vomiting. If conscious and alert,
rinse mouth and drink large quantities of water. Contact staff
5.2.1. CLCC: Absorb spill with inert material (e.g. vermiculite, sand, or earth),
then place in a suitable container. Avoid runoff into storm sewers and
ditches which lead to waterways. Provide ventilation.
5.2.2. Sulfuric Acid: Ventilate area. Neutralize with alkaline material (e.g. soda
ash, lime) then absorb with inert material (e.g. vermiculite, sand, or earth),
then place in a suitable container. Do absorb with a combustible material
like sawdust. Do not flush to sewer.
5.3.1. CLCC: Substance is nonflammable; use agent most appropriate to
extinguish surrounding fire. Approach fire upwind to avoid hazardous
vapors and toxic decomposition products. Runoff from fire control or
dilution water may cause pollution.
5.3.2. Sulfuric Acid: Substance is nonflammable; use agent most appropriate to
extinguish surrounding fire. Contact with water can cause violent
liberation of heat and splattering of material. Contact with metals may
evolve flammable hydrogen gas. Approach fire upwind to avoid
hazardous vapors and toxic decomposition products. Strong dehydrating
agent, which may cause ignition of finely divided materials on contact.
Oxides of sulfur may be produced in fire. Runoff from fire control or
dilution water may cause pollution.
Report all accidents (injuries, spills, fires) to the SSEL On Call or other
SSEL staff. For emergencies during non-business hours, call the SSEL
Emergency Response Team at (734) 764-4127 or Department of Public Safety
at (734) 763-1131.
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