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5.0 Appendices

Described here is a general list of criteria of cleanroom- and non-cleanroom-compatible materials. These guidelines are subordinate to the "Acceptable Materials" policy.
The following materials are generally acceptable to bring into the cleanroom:
• Cleanroom notebooks and cleanroom paper (available in Stores.)
• Wafers and tweezers, in labeled boxes.
• Pens (preferably, ball-point).
• Materials with smooth, hard surfaces, which can be cleaned with alcohol wipes.
The following materials are not considered cleanroom-compatible:
• Wood pulp-based paper products, which includes regular paper, tissues, cardboard, books, and magazines.
• Styrofoam products.
• Any powders.
• Erasers, pencils, felt-tipped pens (other than Sharpie markers).
• Anything that can easily shred or aerosolizes; i.e., anything that may serve as a source of particles.

Manual wafer transfer using tweezers:

  1. Obtain tweezers.
    • Make sure they are made of the appropriate material for your process.
    • Make sure they are decontaminated to the appropriate level of cleanliness for your process (see tweezer clean procedures on the SNF website.)
  2. Obtain an empty receiver cassette.
    • Receiver cassette is the one which you are going to transfer wafers into.
    • The donor cassette contains the wafers to be transferred.
  3. Place the cassettes next to each other, with their H-bars facing the same direction.
    • By convention, the backside of the wafers (the dull, unpatterned side) should face the H-bar.
    • If you are right-handed, it is recommended to orient the cassettes so the H-bar is to the right (the wafers face left, making them easier to see while transferring.)
  4. Using your tweezers:
    • From the donor cassette, grab a wafer at its edge. Ensure the tweezers grips do not touch any device areas, but place them far enough in to get a good handle on the wafer. This is typically about 3-4 mm from the edge. If you are using metal (or Teflon-coated metal) tweezers, they will usually have convenient metal prongs, or “stops” which help guide placement of the grips.
    • Lift the wafer straight up and out of the cassette. Movement should be smooth and silent; avoid scraping your wafer along the sides of the cassette slot, as this generates particles.
    • Place the wafer into the receiver cassette. Movement should be smooth and scraping should be avoided. Ensure the wafer is not “cross-slotted.” (Improperly slotted wafers cannot be picked up by automated equipment and can lead to breakage.)
    • Where possible, start the transfer of the donor cassette from BACK to FRONT. Where possible, place the wafers into the receiver cassette from FRONT to BACK. Working the donor and receiver cassettes in this way helps avoid scratching the front side of a wafer by the wafer being moved.
    • It is good practice (and helps to minimize contamination) if you place the cassettes in such a way that you can avoid working over the wafers.
"Flip” or “Roll” Transfer" of wafers:
  1. Obtain an empty receiver cassette.
    • Make sure it is the appropriate kind and level of cleanliness for your process.
    • Make sure you are wearing clean vinyl gloves.
  2. Place the receiver cassette upside down over the donor cassette.
    • The protruding pins should mate with the alignment holes on both sides of the cassettes.
  3. Grasp both cassettes in both hands. Make sure you have a firm grip on both cassettes and that they are properly aligned and mated; otherwise, you risk dropping (and thus damaging) all your wafers. Gently tilt both cassettes so that your wafers roll from one cassette to the other.
  4. Your wafers have now been transferred.
Wafers should not be touched with gloved hands, even clean vinyl gloves (which have plasticizer residue). Good, careful handling practices will help ensure wafers are undamaged and minimize the possibility of contamination which could adversely affect device processing and performance.

SNF Rules of Conduct are based the principles of Safety, Community, Respect, and Integrity. EVERYONE in the lab community, lab and staff members, and visitors alike, is expected to abide by these principles.


Corrective or Disciplinary Measures:

Any member of the community who violates of any of the above principles is subject to corrective or disciplinary measures. Circumstances such as the experience level or demonstrated repeated behaviors may be taken into account. Disciplinary actions may take the following forms:


As a teaching organization, we understand that the vast majority of violations are simply mistakes, best addressed through retraining or mentoring as appropriate; the rare, intentional violations are addressed on the strictest terms. We believe the greatest resource in our lab is the lab community and strive to foster a culture that places high value on mutual respect and personal and scientific integrity.

  1. Safety is of the utmost priority. Community members must behave in a safe, conscientious, and professional manner in all lab activities. Each individual is responsible for his/her own safety—AND the safety of his/her fellow labmembers. We recognize the need to test and develop new ideas and capabilities; your responsibility is to work with staff and other knowledgeable people to ensure that any new procedure/chemical/equipment is introduced in a safe manner. It is also your responsibility to address any safety concerns you may have with fellow lab and even staff members. The best response is to address the issue directly with the person concerned. If this is not practical, you should report the concern to the staff person responsible for the station in question or senior management, as appropriate. To report any potentially unsafe conditions or practices, or to offer suggestions for improving safety, you can contact any staff member or direct an email to
  2. Community: In a shared lab, everything each individual does can and will affect others, thus, it is everyone’s responsibility to minimize the impact of activities that can adversely affect others and contribute positively toward the good of the community. Remember, this is YOUR lab.
    • Contamination. Labmembers are responsible for ensuring their work does not result in the contamination of equipment or labware which can harm the work of others. All new materials and processes must be approved through the Prom (
    • Communication. Effective communication is essential to success in the lab. Report equipment and process issues on Badger Use email lists to inform or negotiate with others. When differences arise, make every attempt to communicate your needs and respect those of others.
    • Sharing. Because equipment and workspaces are shared, everyone is responsible for being a good lab citizen. Clean up after yourself. Respect Badger reservations. Log run data in station logbooks. Consideration for equipment and all others who share it is everyone’s responsibility. 
  3. Respect: All members of the SNF Lab community are expected to abide by the Statement of Respectful Workplace: “The Stanford Nanofabrication Facility is committed to providing an environment that is conducive to high-quality research, learning and productivity. Effective interpersonal communication is essential in this environment. As such, all members of the community (students, industrial visitors, staff and faculty) are expected to act in a manner based on courtesy, civility, mutual trust and respectful communication. All members of the community should treat one-another with an awareness of the potential impact of their interactions, and strive to conduct themselves at the most respectful and professional level.” 
  4. Integrity:
    • Take responsibility. Everyone makes mistakes. But it is expected that each person take responsibility for his or her actions so that measures can be taken to minimize the problem or prevent it from recurring. For example, a labmember who accidentally contaminates an acid bath should inform other labmembers who may be affected as well as the staff member responsible for the station, and if trained, should also decontaminate it.
    • This is YOUR lab; take care of it. Clean up after yourself; leave no trace except for Badger. If the station is messy before you start, depending on the situation you can: ask the person before you to clean it up, clean it up yourself, or report it to Staff. Do not do nothing! 
    • This is YOUR lab; contribute! Enhance the process knowledge base of the lab by contributing your measurements, observations, and comments to the tool’s Wiki page. By taking the time to document your results, you will be helping your own run, as well as those of other labmembers. 
    • Enable equipment when you are using it; disable when you are done. Make sure to report any problems or observations and to shutdown when potential damage to the machine or other labmembers’ experiments is suspected. Observe good lab manners when making and using reservations. Remember, your accounts are subject to the Stanford University Computer Usage and Network Usage Policy. Make sure to read and abide by this policy (
    • Act according to the intent of a policy. Just because there is no rule against a practice does not make it acceptable. Making reservations you do not intend to use, for example, is not acceptable. Rules are imperfect; but acting with consideration for others is always respected.
    • Community service. A commitment of time or completion of a task that benefits the lab community.
    • Disqualification on one or more tools.
    • Notification of the PI.
    • Restriction or limits placed on lab use (for example, daytime use only).
    • Revoking of lab access and privileges.

Locations:  Video cameras are installed in areas related to SNF operations:

  • Inside the lab:  in each cleanroom process bay, the satellite labs (ExFab and MOCVD), and the Stockroom.
  • Outside the lab: Receiving area (yard, gates, office); gas vaults; subfab entryways

Purpose:  Video monitoring will be used as follows:

  • Safety:  Live video feed displayed on large screens supports the “buddy system” after hours. 
  • Security:  Areas where hazardous materials and equipment are stored or used are monitored by the video system.
  • Training:  Video cameras in the lab may be used for remote training and educational purposes. 

Use and Authorization:

  • Video is recorded and stored for at least 31 days. No sound is recorded. 
  • Live video feed is not available for remote viewing by the public.
  • Access to remote viewing, recorded images, and cameras control is restricted to Authorized Staff.
  • Authorized Staff is comprised of: SNF staff, Stanford’s Office of Public Safety, and agents designated by Stanford.  Such agents may include local emergency responders.  When the video monitoring system is used for of educational purposes, the designated agents may include program collaborators.
  • Only Authorized Staff may access incidental recorded images and only for the purposes of monitoring or investigating operational concerns in the lab, including issues of safety, equipment or facility problems, compliance with lab or university policy.
  • Authorized Staff will not allow video access to non-Stanford entities for purposes related to their own business operations (such as employee performance.)  Non-Stanford entities must initiate a legal investigation to access these materials.  
  • When recording for educational purposes, it is possible the images may become public.  Therefore:
    • The lab community will be informed of the time and location before recording takes place. 
    • Permission must be obtained from any identifiable individuals who may appear in the recordings.
  • Video monitoring serves Stanford’s interest in maintaining a safe and secure laboratory environment, and may not be used for personal or other non-business purposes.
Last modified: 13 Oct 2022