Birck Nanotechnology Center

Operating Policies and Procedures

Nanofabrication Cleanroom Procedures

Specific to the Nanofabrication Cleanroom Only


6.1 Clothing Requirements

6.2 Cleanroom Access

6.3 Growing Process

6.4 Degowing Process

6.5 Material Entry Procedure

6.6 Equipment Maitenance Procedure

6.7 Housekeeping Procedure

6.8 Cleanroom Evacuation Policy

6.9 New Process Approval & Process/Equipment Issues


6.1 Clothing Requirements

Glasses must be worn at all times in the cleanroom.  Safety glasses with side shields are strongly recommended


6.2 Nanofabrication Cleanroom Access


6.2.1 Training Documentation

No one will be allowed access to the BNC Nanofabrication cleanroom until they have submitted documentation to the BNC Safety Coordinator certifying that they have received proper safety training, nanofabrication cleanroom training and certification (if applicable).  Appropriate safety guidelines issued by, but not limited to, the BNC, Purdue CHP (Chemical Hygiene Plan), OSHA (Occupational Safety and Health Administration), and NFPA (National Fire Protection Association) will be followed.   See Section 2.3 Nanofabrication Cleanroom Entry and Section 4.2 Safety Training Documentation.


6.3 Growing Procedure


6.3.1 Pregowning


Hair Cover

Bouffant cap of spun-bonded polyolefin with elastic closure.  Cap must be large enough to contain all hair and elastic must allow snug fit on head.  Use care to ensure that all loose hair is contained within the cap.

Shoe Cover

Shoe cover of spun-bonded polyolefin with elastic closure at top.  Shoe cover must provide good traction on cleanroom flooring surfaces.

 


6.3.2 Gowning


Hood

Open-face hood with two snap adjustments on crown and one snap adjustment on rear, with double two-snap closure at neck and two interior snaps per side for veil attachment.  Fabric is Burlington C-4 or equivalent.

Face veil

Disposable Kimberly-Clark Ranger, or equivalent, snap-in veil.  Veil is worn inside the hood.

Jumpsuit

Full jumpsuit with front zipper and military collar, knitted cuffs on sleeves and snapped cuffs on leg.  A snap or loop at the collar of the jumpsuit for hood attachment when not in use is also required. Fabric is Burlington C-4 or equivalent.  Cuff material is antistatic knitted material suitable for Class 10 cleanroom use.

Boot

Conductive-molded-sole boot with fabric upper.  Four adjustment snaps at top, and possibly vertically arranged snaps for attachment to jumpsuit leg.   Sole material is “Aussie” sole, ChemStat 939E Plus, or equivalent.   Fabric to be Burlington C-4 or equivalent.

 


6.3.3 Pregowning Procedure

  1. In the pregowning area, select a pair of shoe covers.  Sit on the step-over bench, and lift one leg off the floor.  Place the shoe cover over your shoe, and then rotate that foot to the clean side of the bench.  Place foot on clean-side floor.  Lift other foot and repeat the procedure, moving foot across bench after the shoe cover has been put on.

  2. On the clean side of the step-over bench, select a hair cover.  Put on the hair cover making sure that all hair is contained inside the cover.  It is suggested that the hair cover not cover your ears to make it easier to hear while in the nanofabrication cleanroom.

  3. Swipe your nanofabrication cleanroom access badge through the card reader and enter the air shower.  You may not allow anyone else to enter the cleanroom air shower with your card swipe.  The air shower will begin automatically.  When the cycle is finished, enter the gowning room.

  4. No one may enter the gowning room for any reason without following the pregowning procedures.


6.3.4 Gowning Procedure – Fresh Garment

  1. Enter the gowning room and select a nanofabrication cleanroom hood, face veil, jumpsuit, and boots.  Take them to a gowning station to begin the gowning process.
  2. Snap the face veil inside the hood, and pull hood over your head.  Use care to ensure that all hair remains inside the hair cover while putting on the hood.  Snap the appropriate neck snaps of the hood.  Adjust the hood using the adjustment snaps on the top of the hood and the rear of the hood to ensure a snug, comfortable fit.  Press the wire in the face veil over the bridge of the nose to ensure a snug fit.
  3. Put on the nanofabrication cleanroom jumpsuit without allowing any portion of the jumpsuit to touch the floor.  The recommended procedure is to gather the arm and leg cuffs at the bottom of the zipper of the jumpsuit.  Be seated on the gowning bench, and place one leg into the leg of the jumpsuit while releasing that leg from the zipper bottom.  Pull the jumpsuit on that leg such that it completely clears the shoe cover.  Repeat this procedure for the second leg.
  4. Holding the sleeves of the jumpsuit at the bottom of the zipper, arise and pull the waist of the jumpsuit to your waist.  Put one arm into the appropriate arm of the jumpsuit while releasing that cuff.  Repeat with the second arm and pull the upper part of the jumpsuit into place.
  5. Adjust the jumpsuit such that it is comfortable, and zip the front of the jumpsuit to the top of the zipper.
  6. Be seated on the nanofabrication cleanroom bench and put on the nanofabrication cleanroom boots, ensuring that the upper of the boot does not touch the nanofabrication cleanroom floor.  Adjust the fit of the boots with the buckles, and snap the boot snap to the snap on the calf of the jumpsuit.  Snap the boot cuff to provide a snug, comfortable fit.
  7. Proceed to the gowning room mirror, and adjust the fit of your nanofabrication cleanroom garments.  Put on your nanofabrication cleanroom gloves such that you only touch the cuff of the glove.  Adjust the fit of your gloves with both hands gloved, then put on your safety glasses.
  8. Proceed to the nanofabrication cleanroom air shower and enter.  The shower will begin automatically.  Hold arms up vertically and rotate three times in the air shower to effectively allow the air pressure to cleanse the exterior of your cleanroom garments.  When the cycle is complete, enter the nanofabrication cleanroom.

6.3.5 Gowning Procedure – Previously Worn Garment

  1. Enter the gowning room and proceed to your gowning station.
  2. Users are responsible for rotating their used cleanroom garments.  After approximately five uses, all cleanroom garments (including hoods, jumpsuits, and boots) should be deposited in the designated receptacles for laundering.  After setting your cleanroom garments aside for laundering, obtain fresh garments and follow the instructions in Section 6.3.4 “Gowning Procedure – Fresh Garment”. When gowning with previously worn garments, remove the nanofabrication cleanroom hood from the station and, at your option, replace the face veil or continue to use the existing face veil.
  3. Use care to ensure that all hair remains inside the hair cover while putting on the hood.  Snap the appropriate neck snaps of the hood.  Adjust the hood using the adjustment snaps on the top of the hood and the rear of the hood to ensure a snug, comfortable fit.  Press the wire in the face veil over the bridge of the nose to ensure a snug fit.
  4. Put on the nanofabrication cleanroom jumpsuit without allowing any portion of the jumpsuit to touch the floor.  The recommended procedure is to gather the arm and leg cuffs at the bottom of the zipper of the jumpsuit.  Be seated on the gowning bench, and place one leg into the leg of the jumpsuit while releasing that leg from the zipper bottom.  Pull the jumpsuit on that leg such that it completely clears the shoe cover.  Repeat this procedure for the second leg.
  5. Holding the sleeves of the jumpsuit at the bottom of the zipper, arise and pull the waist of the jumpsuit to your waist.  Put one arm into the appropriate arm of the jumpsuit while releasing that cuff.  Repeat with the second arm and pull the upper part of the jumpsuit into place.
  6. Adjust the jumpsuit such that it is comfortable, and zip the front of the jumpsuit to the top of the zipper.
  7. Be seated on the nanofabrication cleanroom bench and put on the nanofabrication cleanroom boots, ensuring that the upper of the boot does not touch the nanofabrication cleanroom floor.  Adjust the fit of the boots with the buckles, and snap the boot snap to the snap on the calf of the jumpsuit.  Snap the boot cuff to provide a snug, comfortable fit.
  8. Proceed to the gowning room mirror, and adjust the fit of your nanofabrication cleanroom garments.  Put on your nanofabrication cleanroom gloves such that you only touch the cuff of the glove.  Adjust the fit of your gloves with both hands gloved, then put on your safety glasses.
  9. Proceed to the nanofabrication cleanroom air shower and enter.  The shower will begin automatically.  Hold arms up vertically and rotate three times in the air shower to effectively allow the air pressure to cleanse the exterior of your cleanroom garments.  When the cycle is complete, enter the nanofabrication cleanroom.

6.4 Degrowing Procedure

  1. The degowning procedure is essentially the reverse of the gowning procedure. 
  2. On exiting the nanofabrication cleanroom, discard nanofabrication cleanroom gloves in the trash container in the gowning room.  Remove your safety glasses if you do not wear them outside the nanofabrication cleanroom. 
  3. Proceed to your gowning station.
  4. Sitting on the gowning bench, remove nanofabrication cleanroom boots and place in their designated location.
  5. Remove nanofabrication cleanroom jumpsuit by unzipping the front of the garment, and removing the hands and arms from the sleeves of the jumpsuit.  Gather the sleeve cuffs at the bottom of the zipper, and pull the jumpsuit well down below the waist. Sit on the gowning bench, and remove one leg from the jumpsuit, ensuring that the jumpsuit does not touch the floor.  Gather the now-free leg of the jumpsuit with the arm cuffs, and repeat the procedure for the second leg.
  6. Stand up, and grasp the jumpsuit only by the collar, allowing the jumpsuit to hang free.  Place jumpsuit on hanger, again taking care not to allow it to touch the floor.  Hang the hangar on the garment rack.
  7. Remove the nanofabrication cleanroom hood, and snap the hood to the snap at the neck of the jumpsuit.
  8. Exit the gowning room and enter the pregowning area.  Remove the bouffant cap and discard.  Be seated on the pregowning bench, and rotate one leg over the bench.  Remove the shoe cover and step down onto the floor. 
  9. Rotate the second leg over the bench, and then remove that shoe cover.  Discard the shoe covers or store them in your assigned shoe cover bin and exit the pregowning area.

6.5 Material Entry Procedure

There are three routes by which material can enter the cleanroom.  The preferred route for small items – less the 2’x2’x2’ – is the dumbwaiter in the subfab.  The second route for small items is through the gowning room.  The route for larger items is through the equipment/material- entry room on the west side of the cleanroom (blowdown room).


Material entering through the dumbwaiter that is doubly bagged has the outer bag removed at the dumbwaiter; the item is then placed into the dumbwaiter and elevated to the cleanroom level.  In the cleanroom, the inner bag is removed.


For material that is entering through the dumbwaiter that is singly bagged, the bag is to be wiped with 10% IPA: water solution with a cleanroom wiper prior to being place in the dumbwaiter, it is elevated to the cleanroom level, and the bag is removed in the cleanroom.


Material entering through the dumbwaiter that is not bagged is wiped with 10% IPA: water solution BOTH before entering the dumbwaiter and on exit from the dumbwaiter in the cleanroom.

Similarly, items entering through the gowning room or equipment/material-entry room are to have the outer bag removed (or cleaned if no outer bag) on entry of the equipment/material-entry room and the inner bag removed (or cleaned if no inner bag) immediately on entry of the cleanroom.

In all cases, removal of the outer bag (or initial cleaning) is performed by a person in street clothing while removal of the inner bag (or final cleaning) is performed by a person wearing a cleanroom garment.


6.6 Equipment Maintenance Procedures

Equipment maintenance within the cleanroom requires careful procedures to ensure that:  1) No contamination of the cleanroom occurs; 2) No unforeseen interruption of utilities to other cleanroom equipment takes place; 3) The equipment being maintained is returned to service in a clean condition.  Refer to the BNC Nanofabrication Cleanroom Maintenance Manual for procedural details.


6.7 Housekeeping Procedures

Housekeeping procedures must insure that no contamination to the cleanroom occurs.  All housekeeping procedures must comply with all instructions found in the BNC Housekeeping Manual.


6.8 Cleanroom Evacuation Policy

In case of an emergency, including the activation of any and all building alarms, evacuate the cleanroom immediately via the nearest exit.  There is no need to return to the gowning room and/or remove any cleanroom garments.  Every bay and chase in the nanofabrication cleanroom contains an emergency exit door.  Upon exiting the cleanroom, proceed immediately to the SW corner of Burton Morgan and check-in with a staff member.  Upon reaching the Burton Morgan meeting site, you may pause to remove your cleanroom garment.  Once an all clear is given by a uniformed officer, return your garment for laundering.

 

New Process Approval & Process/Equipment Issues

Prior to starting a process in the cleanroom, students will present a 15 minute summary of their proposed research to key staff members.  The Process and Equipment Manager will lead this activity and appoint the staff members who will participate in this review process.  Also, as process problems arise, please contact the Process and Equipment Manager directly via e-mail or in person to discuss the problem. The engineering staff will be happy to assist you in solving the problem and/or providing alternative solutions.  An on-line forum also exists where process and equipment questions can be addressed to the staff.  This forum, called “Ask the Staff,” is located here:      https://engineering.purdue.edu/Intranet/Groups/BNC/AsktheStaff

 

 



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