SMFL Safety

From SMFL Wiki

General Information

This page contains general information about safety in the SMFL.

• SMFL Users Manual(pdf)

• RIT Environmental Health & Safety Website
  • RIT Chemical Hygiene Plan (pdf)
  • RIT Accident Report Form(pdf)

• Lab accidents happen all the time, do you know what to do and how to prevent them?
  • Be able to recognize the hazards you are working with.
  • Eliminate or minimize the identified risks.
  • Evaluate the potential risk - probability and severity
  • Maintain focus on your experiment

• A few sites that detail lab accidents
  • American Industrial Hygiene Association
  • Injuries in School/College Laboratories in USA
  • Laboratory Safety Institute
  • 20 Things you didn't know about lab accidents

Safety Training Information

All users of the SMFL must go through safety training and pass the SMFL Safety Test on a yearly basis.

• Safety Badge Information
  • A valid safety badge is required to use the facilities. You receive a new safety badge after taking and passing the SMFL Safety Test
  • Badges are good for one year from the date of your last safety test
  • Those without a valid safety badge must wear a Visitor Badge - No processing is allowed.

• There are two types of safety training courses offered every quarter.
  • New User Safety Training - for people who have never taken the safety test before
  • Safety Refresher Course - for people who have taken the safety test before and/or have an expired badge

• Safety Training Events

• Safety Test Information & Test Questions

• Listing of people with valid safety badges

Hydrofluoric Acid

Hydrofluoric acid in the SMFL represents a special danger in that it is a toxic. Death can and has occurred from exposure to hydrofluoric acid. The danger arises from the fluorine ion which reacts with the body's calcium to interfere with the transmission of nervous signals, proper functioning of muscles, and electrochemical imbalance. Concentrated hydrofluoric acid represents the greatest danger of fluorine poisoning, but there are other solutions in the SMFL that also represent a fluorine poisoning hazard.

• Hydrofluoric acid (HF) is a corrosive that is used extensively in semiconductor processing. Primarily for the etching of silicon dioxide.
• Ammonium Fluoride is also a corrosive that is used in the etching of silicon dioxide. Ammonium Fluoride is the main component of Pad Etch.
• BOE or Buffered Oxide Etch contains both Hydrofluoric Acid and Ammonium Fluoride.
• Pad Etch contains Ammonium Fluoride and is used for etching silicon dioxide deposited over aluminum.
• Freckle Etch contains Fluoroboric Acid and is used for etching silicon nodules remaining after aluminum etch.

• Special precautions are needed for the safe handling of HF, NH4F, BOE, Pad Etch and Freckle Etch. They should all be considered as toxic and should never come in contact with the users skin.
• Immediate treatment is required should this occur.

• See the SMFL Users Manual for a full description of the dangers of HF and it's treatment.
  • Medical Information about Hydrofluoric Acid and Buffered Oxide Etch (HF & BOE)
  • Paper on HF Fatalities (American Journal of Industrial Medicine)
  • Hydrofluoric Acid MSDS
  • Buffered Oxide Etch MSDS
  • HF Medical Book by Honeywell
  • Centers for Disease and Control Information on HF
  • Image of severe HF burn and description of treatment - somewhat graphic - has a happy ending

Piranha

• A solution for removing photoresist / organic residues from surfaces. A mixture of sulfuric acid and hydrogen peroxide ranging from 1:1 to 4:1

• Piranha solutions are very exothermic when mixed, rapidly heating to over 100C in a short period.

• Safety Reminders For Use of Sulfuric Acid/Hydrogen Peroxide Mixtures
  • It is difficult to dispose of piranha because the waste continues to react and decompose for a long period of time. This builds up pressure in the waste bottles, causing them to burst.
  • Commercially stabilized versions of Piranha are available such as Nanostrip (http//www.cyantek.com/htm/nano-strip.htm).
  • Personal protective equipment is always required when working with piranha solutions .
  • Whenever handling Piranha, only use glass containers, preferably Pyrex.

• • In preparing a Piranha solution, add hydrogen peroxide to the sulfuric acid - slowly!
    • Piranha solution is very energetic and potentially explosive. When being made it is very likely to become hot, more than 100 degrees C. Handle with care.
    • Substrates should be rinsed and dried before placing them in a piranha bath. Piranhas are used to remove residues of photoresist and acetone, not the compounds themselves.
    • Adding any acids or bases to piranha or spraying it with water will accelerate the reaction. This includes some photoresist developers , some of which are strong bases.
    • Leave the hot piranha solution in an open container until cool on one of the SMFL wetbenches.
    • Do not store piranha. Mix only enough fresh solution for each use. Excess solutions should be disposed via the drain (once cool), followed by flushing with copious amounts of water.
    • Mixing hot piranha with organic compounds may cause an a very violent reaction. This includes materials such as acetone, photoresist, isopropyl alcohol, and nylon.

SMFL Imported Chemical Policy

• The SMFL has a large number of chemicals available for use in the facility. There may be times when a chemical needed for a project is not stocked in the SMFL.
• Before any chemical can be brought in, it must be signed off by the SMFL. This applies to all users whether they are internal or external.
• The SMFL Imported Chemical Worksheet needs to be filled out and submitted with the MSDS before the chemicals can be brought into the lab.
  • Fill out sections 1,2 & 6 and bring to T. Grimsley in 17-2175 for review and signoff.

NFPA Hazard Diamond

• The SMFL uses the NFPA (National Fire Protection Association) Hazard Diamond for labeling of chemical containers.
  • Information about the NFPA Label
  • Look up the NFPA Ratings for chemicals
• See the SMFL Chemistry List for specific NFPA ratings for the materials found in the SMFL.

MSDS Information

• The SMFL maintains an MSDS database on the main user computers located in the cleanroom. They are:
  • Gowning
  • Wet Etch 1
  • Wet Etch 2

• The computers are all marked with the yellow /black MSDS sign above them.
• Look for the MSDS icon on the computer desktop to launch the software.