Safety is paramount in LAMP. Due to the nature of semiconductor and microsystems processing, activities within LAMP must be undertaken with extreme care and a full understanding of all proper safety procedures. Violations of safety protocols will result in temporary expulsion from the lab. Permanent expulsion will result from gross negligence of the safety rules. This can mean serious delays or even the end of your thesis. You have been warned!

Outline of the LAMP safety reference guide

    1-  Before you begin: link to safety overview documents: general concepts about chemical handling, storage and disposal
    2-  "The 10 Commandments of LAMP" 
    3- General rules of operation for the LAMP cleanroom: rules that must be followed by any user of the clean-room facility
    4-  Safety policy
    5-  Emergency procedures
    6- Chemicals safety issues
    7- Gas safety issues

There are several important online safety resources you must be aware of:

• The University of Maryland Department of Environmental Safety (DES)
• Online Material Safety Data Sheets ( MSDS) from the University of Maryland website and our MSDS web page where you can retrieve MSDS for the chemicals used in LAMP.

This guide is intended to help in understanding proper chemical  handling and basic cleanroom safety issues. It also present important issues related to the use of hazardous gases in LAMP.

Every user of the LAMP facility must take the following training:

• Take the DES New Laboratory Researcher Training course - required training for all new laboratory research personnel, including information on applicable regulations and guidelines, recommended work practices, selection of personal protective equipment, and proper disposal of hazardous chemicals and biological waste. This training is offered every month.
• Take the DES Chemical Hygiene Training course - All personnel who work with chemicals in laboratories are required to have Chemical Hygiene Training. For your convenience, this training class is offered on-line (see the DES web page). 
• Read carefully this LAMP Safety Reference Guide  , the safety overview document and the LAMP general operating procedures and guidelines.
• Pass the LAMP safety quiz.
• It is also strongly recommended to attend the Safety workshop offered annually at the start of the fall semester by DES, as well as to take the on-line training for Hazardous Waste Management.

Be Safe, Be Neat, Be Clean !!!

1. Before you begin:

 

Carefully read the safety overview document . This guide offers general safety notes when working in a clean room, especially about chemical handling and storage.

2. The "10 Commandments of LAMP"

• Safety is non negotiable. Safety must be your primary concern at all time. 
• Be proactive about safety. If you see a safety hazard, you are  responsible to report it to the lab manager even if it implies other users of the lab. Each person have the right to question a procedure that he/she considers inherently unsafe.
• Never leave the lab without cleaning or in unsafe conditions
• If you break something, you must report it. Occasional accidents are understandable and forgivable. Secrets or continuing mal practice are not acceptable
• Never assume that other users are knowledgeable about your activities. Make sure to clearly  label or mark any recipient, chemical solution, source of potential hazard... you leave unattended (even for a few minutes).
• Each user must take responsibilities in the training and organization of the lab. It is everyone's responsibility to maintain LAMP in order. If you see something wrong, do not assume somebody else will fix it for you.
• Learn from your colleagues and teach them in return.
• Document your activities or problems in the log books put at your disposition in LAMP.
• Report ideas to improve work in LAMP
• Most of all, respect other people's work. Your work is valuable so is other people's work! Be clean, be safe, be considerate and professional.

3. General rules of operation for the LAMP cleanroom

(adopted from the Cornell CNF, CAMD & Micralyne ) :

In this section, you will find general rules that must be known and applied by any users of the LAMP facility. More details regarding chemicals and gas handling can be found in the section 5 and 6 of this guide.

• Dress code and general issues
  • Inside the cleanroom clothing, shoe covers, Tyvek coat (or bunny suit if you are wearing a short or skirt), hair net must be worn at all time.
  • Gloves and safety glasses must be worn all the time when you are in the cleanroom, no matter what you are doing.
  • No Sandals and open-toed shoes.
  • Smoking, food, drinks, chewing-gum are prohibited anywhere in the LAMP facility (cleanroom and pre-cleanroom). They all are huge sources of dust and can present serious safety risks.
  • Torn or dirty coats and shoe covers must be discarded after use. Hair nets are not to be reused.
  • It is not allowed to leave the facility wearing the garments

• Use of equipment
  • Non-authorized users are not allowed to work on any of the cleanroom equipment. To be authorized to work on a specific piece of equipment, you must imperatively contact the tool supervisor in charge (see LAMP Management Team)

  
  

• General storage
  • Because cleanroom space is a premium, make sure to follow these rules or your items will be discarded without notice.
  • Tools, samples and other small belongings can only be stored in the yellow plastic boxes that have been allocated to your group and stored on the metallic shelves in the cleanroom. If you need additional storage space inside the cleanroom, you must contact the LAMP manager.
  • Additional storage space is also available in the LAMP annex (room 2229). As in the cleanroom, specific spaces have been allocated to each group. All items there must be labeled with name, date and phone extension or they will be taken out of the annex.

  
  

• Chemicals storage

  For safety concerns, chemicals inventory is managed by a student supervisor (see LAMP management). He will make sure that all the Materials Safety Data Sheets and product inventory are up to date. 

  You must get the approval of the lab manager or the student in charge of the chemical inventory before importing any new chemicals in the LAMP facility.

  The chemicals inventory is divided into 2 main categories:

  • chemicals for general use that are shared by all the groups (i.e. acetone, methanol, DI water, nitrogen gas...). The supervisor in charge of the chemicals will manage the supply of these chemicals. You are welcome to contact him if re-supply is necessary.
  • chemicals that are used specifically by a research group.

  After pre-approval, chemicals brought to LAMP must be very clearly labeled with the name of chemicals, the date of introduction and the user name. Make sure they are stored safely in the designated area.

  
  

•  Wet processes and other work in LAMP
  • Never use specific chemicals, glassware or other equipment that are  used and labeled by another group.
  • Always clean up your work area before you leave. Thoroughly rinse the beakers you used with DI water and then store upside-down in their appropriate locations.
  • Wash thoroughly any chemical bottle you used. Use cleanroom wipes to dry and then store in the appropriate cabinet.
  • Label all the glassware or fluoroware you are using and specify the contents, your name and the date. If you have to leave the area for a little while, let people know what you are doing in the cleanroom and what chemicals are in the beakers. This also goes for any processing that needs to be carried out over night or more (leave a written note at the work station indicating your return time, a contact name and phone number).
    

• Chemicals disposal
  • All disposed items have to be labeled with the name(s) of chemical(s), the date of disposal and the name of user. If you use recyclable bottle, make sure you remove or scratch away old label.
  • Thoroughly rinse empty chemical bottles with regular tap water. Fill and dump at least 3 times. Put a scratch through the original label and mark it with "WASHED BOTTLE" and place in the designated area beneath the eye wash station.
  • No unauthorized solutions
  • No unlabeled solutions
  • No chemicals in waste baskets
  • No unwashed bottles in waste baskets
  • Never touch exposed skin with your gloves, avoid transfer of oils to the glove surface.

   

The above rules are essential for maintaining normal cleanroom operation. Any one violating the rules will be subject to a warning, suspension of access to cleanroom for one month, or loss of privilege to work in the cleanroom altogether.

Short and Simple Consequences: You can lose access to the LAMP facility if you violate any safety rule or cause injury or damage to persons or equipment.

4. Safety Policy

All LAMP users are encouraged to report all incidents, near misses, and unsafe acts they encounter while working at the lab. It is not intended to criticize or 'pick on' any person. By reporting these incidents, corrective actions may be recommended to prevent similar or more catastrophic incidents from happening. "Incident Report" forms are available in the cleanroom. Notify the lab manager by sending an e-mail.

5. Emergency Procedures

            4-1 Emergency procedure resulting from the leak of silane (see gas safety issues)

As in most semiconductor research facilities, LAMP houses a variety of hazardous gases. Therefore it is equipped with an integrated alarm system that includes a MDA System 16 gas detector (located in front of the middle door in the hallway). This system can detect traces of silane, a highly ignitive gas, at concentration as low as 2 ppm in four different locations of the LAMP facility. It also integrate other sensors (HF, H2, overpressure, overflow...) to provide an appropriate alarm response. If a positive detection occurs, the MDA system 16 will automatically activate the J.M. Patterson building alarm and notify the UM police department. 2 red flash lights  inside LAMP will also be triggered.

In case of such an alarm, anyone present in the lab must:

1. Evacuate the LAMP facility IMMEDIATELY.
2. If the building alarm is not already sounding, pull the manual emergency station located in the hallway for general evacuation of the building.
3. Call 911 to confirm that they have been notified by the automated supervisory unit.
4. Call the lab director (Gary Rubloff @ 301 405 2949) and Laurent Henn-Lecordier @ 301 602 9858 (cell) or 55858 (office).

The LAMP facility is equipped with an emergency push button located to the left of the main entrance door that can be activated manually. By pushing this button, the J.M. Patterson building alarm will be triggered and the UM police department automatically notified.

Please make sure to review the paragraph related to Gas safety issues.

        4-2 General emergency procedure

• In case of fire
  

  Pull fire alarm and follow evacuation procedures
  Notify LAMP staff

• Injuries

  All injuries should be immediately reported to the LAMP staff
  All users are expected to cease work to assist an injured user.
  If large chemical exposure is involved, another user must accompany the injured person to the hospital emergency.
  If deemed necessary, phone 911 and request an ambulance to be sent to the J.M. Patterson bldg (083), room 2225
  An incident report must be completed ("Incident Report")

• Chemical Spills and Exposure

  In the event of chemical spill, first ensure that all injuries are being treated. If chemical exposure (skin, eyes, etc.) has occurred, immediately get to a source of water, remove contaminated clothing, and flush the contaminated area thoroughly for at least 15 minutes. Then, depending on the size of the spill, do one of the following:

  1. If the spill is small enough, then qualified personal may clean it up themselves at their discretion. The incident must be reported ("Incident Report").
  2. If you feel that the spill is large enough to warrant LAMP staff response:

  • Evacuate the immediate area.
  • Clearly mark the area to prevent other users from accidentally entering the spill area. If there are no sufficient tools for marking the area, recruit another user to stand as a "lookout" near any ingress route until LAMP staff (or qualified persons) arrive.
  • Show LAMP staff the exact area of the spill and the nature of the spill
  • Fill out the incident report form ("Incident Report").
  • If at any time a spill is deemed to be a serious hazard to other building personnel (due to size, fire, toxic threat), pull a fire alarm to evacuate the building.

NB: Make sure that you are aware of the locations of eye wash station and emergency shower before working with hazardous chemicals.

6. Chemical Safety Issues

• Authorization

  Only persons who have been trained to handle chemicals at LAMP may use chemicals in the facility.

• Material Safety Data Sheets

  
  MSDS sheets for each chemical we use at LAMP are available (MSDS sheet binder) in the cleanroom area or online for download. If importing a new chemical into the facility, MSDS sheets need to be obtained before purchasing the product. (Link for Online MSDS info).

• Wet processing areas

  
  All the wet etch processes that have been approved by the lab Manager should be done in the wet deck.

• Working with etch solutions requires a "Buddy system"
  

  While working with or preparing chemical etches and baths, another user (Buddy System) must be within range of verbal contact for the purpose of immediate emergency response. For solutions containing HF, another user who has been approved to work with HF, must be in the room.

• Importing chemical into LAMP
  

No chemical may be brought on-site without prior approval by the manager. The lab manager and the user must determine the safety concerns associated with the chemical (if any) and develop procedures for safely working with this chemical.

• Developing new wet processing recipes
  

  There are inherent dangers when developing new etch recipes. Chemical can react in unexpected ways that can create dangerous situations (causing injury, death to users and damage to equipment). If a new process is needed, you must abide by the following procedures:

  1. If the recipe is significantly different than those used previously in the lab, the lab manager must be informed (verbally). You need this approval for any significant recipe modifications.
  2. Before mixing any chemicals, it is your responsibility to look into any reactions that might take place (intentionally or by accident).
  3. When you first mix the new recipe, use first small volumes (<50 ml) of solutions or additives. This will ensure that if the chemicals react in unforeseen ways, the possible explosions or gas releases are small.

• Chemicals: Storage and Handling

  • a-Storage

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 and life. Therefore, you must be alert and cautious when using these chemicals to avoid all "direct" contact with them. The risk of injury will be minimized if the safety procedures are followed.
Acids, bases, and solvents must be stored in separate marked cupboards.

Table1: Concentration of common chemicals in the microfab

• b-Handling

1. Users who handle hydrofluoric acid or HF-containing solutions (BOE) must be authorized by the lab manager prior to handle these chemicals.
2. Know which chemicals and containers are compatible. Some chemicals or mixtures can not be used in plastic (hot Piranha) or in glass (HF).
3. Always work with chemicals under fumehood.
4. Heavy-duty rubber gloves, chemical apron and a face shield must be worn when handling hazardous chemicals.
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 do the reverse. This prevent violent splashing.
6. DO NOT mix organic solvent with inorganic chemicals. This can result in violent reaction or explosion.
7. Never work with acids and bases side by side because violent reactions can occur.
8. DO NOT pour chemicals back into the storage bottle. If you pour too much, dispose of it appropriately.
9. Put the cup back on each chemical bottle securely.
10. Be Cautious all times !!. Because most chemicals used in the lab look like water, always assume any liquid is dangerous if not labeled.
11. Table 2 lists some of the flammable chemicals encountered in the cleanroom.
12. When using hot-plates, check that your beaker is both suitable for hot plate use and smaller than the area of the plate.
13. Always monitor the temperature of the chemicals on a hot-plate with a Teflon coated thermometer.
14. Rinse the heavy chemical gloves with DI water before you take them off.
15. Never touch your skin (face) with your gloves on.
16. A fire extinguisher is located outside the cleanroom. The eye wash station and emergency shower are located in the cleanroom..
17. Hydrofluoric acid (HF) is more dangerous than it seems. Because HF does not hurt when it makes contact with skin, people get careless. READ carefully the Standard Operating Procedure related to hydrofluoric acid prior to any work involving this chemical. Calcium Gluconate Gel is available to treat HF burns. You will find it in the First Aid Kit located next to the lab entrance door.

• Chemicals: Waste Disposal

Contact the student in charge of waste disposal. For general information on Hazardous and regulated waste procedures, please check the DES website.

Please be aware that the disposal of hazardous waste down drains, sinks, etc. is prohibited.

1. Waste Containers

• Hazardous waste must be collected in containers that are compatible with the waste.
• Keep all hazardous waste containers closed at all times unless you are adding or removing waste.
• Label each container of hazardous waste with the UM Hazardous Waste Green Tag when you first place waste into a container.
• Do Not store incompatible waste containers side by side
• You may use a washed bottle as a waste container. Make sure you wash it thoroughly to remove all the previous chemicals and scratch away the original label.

2. Waste Pickup

• Request Waste Pickup system via the DES web page.
• You must take the online Hazardous waste generator training before submitting any waste pickup request.

3. Unknown or Unlabeled waste

  Please be aware that:

• It is the responsibility of each individual generator and department to properly label hazardous materials and identify containers of hazardous waste at the time accumulation begins.
• DES will identify, remove, and dispose of unknown wastes for on-campus waste generators. However, the generator or generating department will incur a $110.00 per bottle fee for all solid and liquid unknown wastes.
• DES will also arrange for a contractor to sample, analyze, and dispose of any unknown cylinders. The generator or generating department will incur
  the full costs of the contractor's services, which can exceed $2,000.00 per cylinder.

4. Procedure for HF disposal

HF is a very Hazardous chemical. Any person who uses it must receive a special training and authorization. The binding of free fluorine ions with Calcium has been recommended for HF neutralization. Calcium chloride can be used to neutralize HF in 6 parts to 1 part of HF.

• Small amount of HF (<75 ml) can be poured down the drain as long as it is neutralized (with CaCl2) and diluted with large amount of water.
• While neutralizing the HF solution, DO NOT add the two reactants together directly. The reaction will be reasonable vigorous and toxic gas may be released.
• You must know that BOE is not a dilute HF. The ratio given on the BOE container is buffer to HF, so the fluorine content is the same as in HF for any ratio. For this reason, the same amount of Calcium Chloride must be used when neutralizing BOE as when neutralizing HF.
• Large amounts of HF solutions (>75ml) must be collected in a plastic container, properly labeled as a hazardous waste.
• Do not completely fill up the waste container with HF solution.
• Store the waste container in the designed safe area.
• Call for waste pick up

5. Piranha Hazards

A piranha is used to remove organic residues from substrates. Two different solutions are used. The most common is the acid piranha: a 3:1 mixture of concentrated sulfuric acid (H2SO4) with hydrogen peroxide (H2O2). Also used is the base piranha: a 3:1 mixture of ammonium hydroxide ( NH4OH) with hydrogen peroxide (H2O2). Both are equally dangerous when hot, although the reaction in the acid piranha is self-starting whereas the base piranha must be heated to 60 degrees before the reaction takes off.
There are many things which will cause the reaction to accelerate out of control. "Out of control" can mean anything from the piranha foaming out of its bin and on the deck, to an explosion with a huge shock wave including glove and acid-gown shredding glass sharps. Piranhas burn organic compounds. If you provide sufficient fuel for them (i.e. photoresist, IPA), they will generate enormous quantities of heat and gas.

Important safety notes:

• Never store piranha. Leave it in an open container until completely cool. Then aspirate the cool solution. A piranha stored in a closed container will explode.
• Hot piranhas explode when mixed with acetone and other organic compounds. This includes IPA, photoresist, and anything made out of nylon like spinner and developer chucks.
• If you put any acid (i.e. chrome etch) in the base piranha; it will accelerate due to the heat generated.
• Likewise, if you put any base (i.e. developer solution) in the acid piranha, it will accelerate.
• Photoresist developer is a strong base. It can cause blindness if left in the eye, and can react violently with acids. Be extremely careful in working with developer.
• Water sprayed into either piranha will accelerate the reaction. A single wet wafer doesn't introduce enough water to make a difference, but a boat with 25 wet pieces of glass could.

Instructions for safe use of Piranha:

• Substrate should be rinsed and dried before placing them in a piranha bath. Piranhas are used to remove photoresist and acetone residue, not the compounds themselves.
• Do not store wash bottles containing organic compounds on the piranha deck.
• No crystal bond stripping on the piranha deck.
• No Photoresist stripping near piranha deck.
• Cold acid Piranha can be used to clean glass Chromium photomasks

7. Process Gas Safety Issues

At the exception of nitrogen which is shared by all the users of the lab, other gases are administered by each group for their own needs. Nevertheless because of safety concerns, importing new gas cylinders into LAMP must be approved in advanced by the lab manager.

As explained in the section 5 of this guide (emergency procedures), hazardous gases are used in this lab and therefore every person working in LAMP should be clearly aware of the emergency procedure resulting from an accidental gas release.

MSDS sheets for each gases we use at LAMP are available (MSDS sheet binder) in the cleanroom area. If importing a new chemical into the facility, MSDS sheets need to be obtained before purchasing the product. (Link for Online MSDS info). The MSDS for the gases currently used in LAMP can be viewed at the following link.

Users of LAMP who are directly handling these gases should also read the following Standard Operating Procedures for the use of gases in LAMP. This SOP offers a detailed description of the alarm system put in place in LAMP to detect and annunciate the presence of hazardous gases.

                               LAMP SOP for process gases

                               LAMP Emergency system (summary table)

Standard Operating Procedure to handle WF6