SAFETY RULES AND RESTRICTIONS

The following safety rules are to be observed by all persons qualified to work in the ERC Micro and Nano Engineering Facility (MNEF).

The chemicals used in the cleanroom are extremely hazardous. Table 1 below lists some of the more common chemicals used in the lab and their concentrations. Many of these chemicals can cause severe damage to human tissue. Therefore, you must be alert and cautious when using these chemicals to avoid all contact with them. When you follow the appropriate safety procedures, your risk of injury will be minimized.

1. DO NOT use a chemical in the cleanroom without first reading its MSDS.

2. Know which chemicals and containers are compatible. Some chemicals, such as TCE, cannot be used with plastic beakers. Some chemicals, such as HF, cannot be used with glass beakers.

3. Always work with chemicals under the fume hood. Heavy-duty rubber gloves, a chemical apron, and a face mask must be worn when handling hazardous chemicals in the cleanroom. Table 2 below contains a list of some of the corrosive liquids used in the lab.

4. Use the DEDICATED beakers only with the chemicals and/or process labeled on the beaker. Do not cross-contaminate beakers. Do not remove beakers from the cleanroom.

5. When mixing chemicals, use only one bottle at a time. Do not open a new bottle unless an existing bottle is completely empty. Pour the chemical slowly. Do not let it gulp. Remember the Triple A Rule: "Always Add Acid to water," never the reverse. This prevents violent splashing. Do not mix organic solvents with inorganic chemicals. This can result in a violent reaction or explosion.

6. Don't pour chemicals back into the storage bottle. If you pour out too much, dispose of it appropriately.

7. Put the cap back on each chemical bottle securely. If necessary, rinse the outside of the bottle before you return it to storage.

8. Exercise extreme caution at all times! Because most chemicals used in the lab look like water, always assume any liquid is dangerous.

9. Do not leave your chemicals unattended. If the chemicals will be in use for several hours, you MUST clearly mark the name of the chemicals, your name, where someone can contact you, and when you expect to return.  This information can be put on a clean wipe under the container such that all information can be read without moving the container.

10. When using hot plates, check that your beaker is both suitable for hot plate use and smaller than the area of the plate. Never use a Teflon or plastic beaker on a hot plate. Always monitor the temperature of the chemicals on a hot plate with a Teflon coated thermometer. Table 3 lists some of the flammable chemicals encountered in the cleanroom.

6. Rinse the heavy chemical gloves with DI water before you take them off.

7. Always clean up your work area before you leave. Thoroughly rinse beakers you used with DI water and then store upside-down in their appropriate locations.

8. Tell Dr. Hogan and/or your advisor about any unsafe situation. Use your judgment. For example, if a beaker of chemicals is sitting around without a label, report it.

9. If you are not sure something is safe, ask your supervisor. Use common sense. There are no unexpected dangers in the cleanroom, but do not touch anything unless you are sure you understand it.

10. Wear safety glasses when using the spinner. Safety glasses are available in a box to the right of the spinner. The spinner sometimes breaks silicon wafers. When this happens (about once every thousand wafers), silicon shards may be ejected. Silicon chips are about as dangerous as broken glass. Wear safety glasses when using the spinner to protect your eyes from flying chips. It is a good habit to always wear safety glasses in the cleanroom, taking them off only to use a microscope. This is a rule for everyone in a room when someone in that room is doing spin, develop, etch, or strip. Aprons are available to protect your clothing. A drop of photoresist may splash onto your clothing and make a permanent spot. The spinner is well ventilated; if you smell the solvent in the room, discontinue work and notify the lab superior. Open your resist vial close to the spinner chuck; opening far away from the chuck ventilation may cause other students to smell the solvent. These solvents are known to cause birth defects when inhaled by pregnant women.

11. Hydrofluoric acid (HF) is more dangerous than it seems. Because HF does not hurt when it makes contact with skin, people get careless. HF hurts badly when it makes contact with eyes, lips, fingernails, etc. The pain may not start for a few hours, but it may last for days. For HF burns, get medical help immediately.

12. Wash your hands when you leave the cleanroom.

13. Policies for Gases:

a.       New gas cylinders should be labeled with the date of arrival.

b.      Empty gas cylinders should be labeled with date it was noted empty.

c.       Empty gas cylinders should be stored in gas storage room (B110).  A gas cylinder truck must be properly used to move the cylinders.

14. Policy for Chemical Storage:

a.       Chemicals are stored based upon their contents and color code. Only store chemicals in their appropriately labeled cabinets and locations.

15. Policies for Acid and Bases:

a.       When handling acids or bases, gloves, apron, face shield, and lab coat must be worn.

b.      All acid and base work must be done in an exhausted fumehood.

c.       Acids are stored in the cabinet labeled "ACIDS".

d.      Bases are stored in the cabinet labeled "BASES".

e.       Never work with acid and bases side by side because violent reactions can occur.

g.       Storage of waste acids will be done by storing the acids in clearly labeled waste containers for that particular acid. Do not mix the acids together. Waste acids should be stored in separate containers in the acid cabinet.

i.         Storage of waste bases will be done by storing the bases in a clearly labeled waste container. Ammonium Hydroxide will be stored in a clearly labeled waste container. Potassium Hydroxide, Sodium Hydroxide, and positive photoresist developer can be stored together in a clearly labeled waste container.

k.      Storage of the waste acids will be in the acid cabinets and storage of the waste bases will be in the base cabinet.

16. Policies for Solvents:

a.       All chlorinated solvents must be stored in a clearly labeled waste solvent container for proper disposal.

b.      Trichloroethylene (TCE) and Trichloroethane (TCA) should be kept in a separate solvent waste container from Acetone, Methanol, and Propanol. (Acetone, Methanol, and Propanol can be disposed of through incineration while TCE and TCA cannot due to carcinogens.)

c.       On all solvent waste containers will be a label. On this label will be three columns that need to be filled out when a waste solvent is poured into that bottle. Column one is the CHEMICAL NAME, column two is the CONCENTRATION (%), and column three is the QUANTITY. The chemical name is the proper chemical name not the manufacturer's name. An example is Microposit Remover 1165 is the manufacturers name, the proper chemical name is N- methyl 2-pyrrolidone. Most solvent containers have the proper chemical names listed on them.

d.      Keep all flames away from the solvents because most solvent are highly flammable.

17. Policies for Solids: Solids must be stored in an appropriate container and clearly labeled for disposal through the ORCBS safety department.

a.       Policies for Mercury:Mercury can be picked up with a mercury spill kit.  Contact ORCBS immediately after a mercury spill.

 

Intentional violation of any cleanroom rule or safety rule will result in suspension or expulsion from the cleanroom.

 

If you are unsure about any procedure, or condition in the cleanroom, contact the system administrator for that piece of equipment, Tim Hogan, and/or ORCBS.