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Miscellaneous Photoresist Wet Bench, wbmiscres

The wbmiscres wet bench is primarily used for manual spinning and developing of photoresist. No solvents may be used here. The bench is equipped with a rinse sink with a gooseneck, an automatic dump rinser, two N2 guns, DI hand sprayer, and hot plate. There are two spin/rinse dryers located to the left of the bench for 4 or 6 inch wafers. The headway manual spinner is mounted on the right side of the bench top.

Picture and Location

 Wet Bench Miscellaneous

The tool is located at FG3 on the Lab Map.


Process Capabilities

Cleanliness Standard

 The wbmiscres wet bench appears in all three equipment groups (clean, semiclean, and gold).


How to Become a User


  1. "All Litho" is required before training on any of the lithography tools. Contact the trainers for the class schedule and training materials (which must be reviewed before the class). If no training hours are indicated, training for the tool is covered in the "All Litho" session.
  2.  Contact SNF training contact on the Equipment Summary page.

Operating Procedures


DEVELOPER or RESIST only! SOLVENTS are not allowed!

No other acids or bases (like KOH) are allowed at this wet bench.

The rinse sink, dump rinser and spin-rinse dryers drain into the general lab acid waste neutralization system AWN. These modules may be used only when the AWN is functioning. When there is a problem with the AWN, the yellow light (above wbnonmetal and wbflexcorr-1and-2) will flash. When the yellow light flashes, no draining of developer or water is allowed. 

The left side of the bench (sink, dump-rinser, SRDs) is only used for beaker develop using non solvent developers like MF-26A (which contains 2% TMAH).

The right side of the bench is used for manual photo resist spinning using the Headway. Extra training is required for the Headway.

Teflon Litho cassettes: brown buttons only

  • Litho cassettes with brown buttons should be used only in the photolitho area, not in other areas!
  • Litho cassettes with one brown button for the photolitho area are kept on the top of this bench.
  • Litho cassettes with two brown buttons are only allowed in the YES oven.
  • Litho cassette with three brown buttons is reserved for the ASML and stored in a black box.
  • Only Litho cassettes with one brown button are allowed in the ovens (temp up to 150C).
    Exception: The high temp. BLUE M oven requires quartz boats, because the temperature can reach 400C.
  • Do NOT place regular storage cassettes or boxes made out of plastic into any of the ovens, they will melt!
  • Do NOT store wafers in Litho cassettes. To store wafers use your own plastic cassettes and boxes from the stockroom.
  • Litho cassettes allow wafers from all equipment groups.
  • Do not use Teflon cassettes from other areas with different colored buttons in the litho area.


  • MUST be completely filled out and left along side all open containers of chemicals (beakers etc.). THIS INCLUDES CONTAINERS of DI WATER!!
  • Complete chemical names of all chemicals in the solution along with your Badger information must be listed.
  • At this bench ONLY you may use the product name if there is an MSDS sheet in the book located at the bench for the product.

Containers of developer or photoresist:

  • Because the exhaust works best in the back of the bench, keep all open containers of developer or photoresist back at least 6 inches from the front of the wet bench, the red tape indicates 6 inches.
  • Cover open containers of resist with foil when transferring them in a metal cart to the coater or to the “lithosolv” bench for disposal. See the note posted at “lithosolv” for more information.
  • Non-solvent developers to be used at this bench should be poured at the bench and not transferred from the bench. They can be poured down the drain when you finish using them.
  • Solvent developers like the SU8 developer are only allowed at the litho solvent bench.



You must have approval from the Process Materials (PROM) Committee before bringing any new resist or developer into the litho area. If you would like to use your approved personal resist or developer bottle, you have to fill out a special yellow label. Yellow labels can be obtained only from Mahnaz Mansourpour.


We are required by the Stanford University - Utilities Services (Environmental Quality and Water Efficiency) to distribute the Best Management Practices (BMP) fact sheet, you'll find the link here in the Stanford University - Utilities Services folder.
Please read the fact sheet and reduce the amount of pollutant for example by using smaller quantities of chemicals.




As of  August 2008, there is a new handling procedures for manual dispensing of standard resists.  Small, easy-to-handle bottles of standard resists are provided for your convenience in the small flammables cabinet next to the wbmiscres/headway2 station (special thanks to Mario, Jim, and Mahnaz!)  Please use these bottles for manual dispensing at the headway2 and laurell stations only.  Bottles may be hand-carried and used ONLY AT HEADWAY OR LAURELL STATIONS.  They must be returned to the cabinet when finished.

The standard resists stocked are: SPR 3612, SPR 3617M, SPR 220-7, SPR 220-3, and LOL 2000.  Do not place other resists in this cabinet.  (Any non-standard resist bottles found here will be removed and discarded.)  Be courteous to the next user -- make sure to use care to avoid drips -- and carefully wipe away any that might occur.
We trust that these smaller bottles are safer than handling the large one-gallon jugs -- and may save people a trip to the back with the solvent cart.
Your Litho Staff


As of November 2012, there are now two dedicated spin-rinse dryers (SRDs) just to the left of this bench.

Spin-Rinse Dryer (SRD)




High RPM,

Thin wafers, chipped wafers, wafers that are scribed deeply,

Stressed wafers, etched through wafers, wafers with jagged edges,…

Make sure wafers are not “cross slotted” in the cassette!


Wafers might stick to the Teflon rod after the spin-dry!

Use extreme caution when removing the cassette!


Do not run the spin/rinse dryers without a cassette!

The SDRs are for 4 inch wafers, for 6 inch wafers by request only.

Recipe # 1:

Step RPM Time sec
1 0 20
 0     x
 2 400 180
x   x
 3 1500
 4 2000 150 0   x   x    
 5 1500 120
 6 600 60 0   x  



  • Open the door to the spin-rinse dryer if you use a 4" cassette and carefully load the cassette.
    If you have a 3" cassette, you must insert the special stainless steel adapter into the spinner assembly first, then load your cassette. Use clean gloves to handle the adapter.
    If the cassette is not full, the wafers should be evenly spaced throughout the boat.
  • Close the door.
  • Select recipe #1.
    If recipe #1 is not selected, press + or - until recipe #1 is on the display.
  • Press the green START button to start the cycle. If the resistivity does not reach the set point within 180 seconds this module will continue in the slow spin/rinse step of the cycle until the resistivity reaches the set point in M/ohms. When resistivity is reached, the fast spin/dry step will start.
    When the cycle is done, the rotor will stop spinning and the door interlock will be released. Open the door and make sure that the cassette is upright. The wafers might stick to the Teflon rod after the spin-dry! Use extreme caution when removing the cassette (remember, clean gloves!).
  • Place the cassette into the station dedicated box and return the station dedicated cassette and box to this wet bench after loading the wafers into the next tool. Do not store your wafers in the station dedicated Teflon cassette!


 If the SRD has not been run for one hour, an Auto Cycle (A on display) will start, it will rinse and dry the bowl at a low RPM, there should be no cassette inside of the tool. The Auto Cycle does not close the door. The machine will not start an Auto Cycle if the door is open or the controller is interlocked. If the programmed time interval has expired, the tool will continue to attempt starting the Auto Cycle, so as soon as the door is closed, the Auto Cycle will start.

If the Auto Cycle (A) is running, wait until it finishes and then load your cassette, try not to open the door while a program runs.  

 If "Idle" or "resistivity" flashes on the display, press the STOP button.

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