WisconsinCenter for Applied Microelectronics

1550 Engineering DrivePhone: 608/262-6877

Madison, WI 53706Fax: 608/265-2614

Deflecking Aluminum Etch Bench Operationand Quick Dump Rinser

Rev. 8/7/12

Material Restrictions:

All materials allowed for use in this equipment are listed in PDF form on the WCAM My Web Space. To view the listing following these steps:

  1. Open the UW website for My WebSpace.
  2. Log on using your UW NetID and password.
  3. Click on the star in the upper left corner.
  4. Under Bookmarks click on Group Directories.
  5. Scroll down the list of organizations to WCAM.
  6. Click on WCAM.
  7. Double click on the first file folder to open “Approved Materials.”
  8. Double click on the WebsiteRpt to view the approved materials for equipment.
  9. Within the PDF you can perform a search.

Personal Protective Equipment (PPE)

While working at etch bath you must wear:

  1. Face shield and safety glasses
  2. Chemical apron
  3. Chemical gloves over the nitrile gloves

Materials

  • Silicon, silicon on insulator, quartz
  • NO METALS, metal tweezers, glass, Ga/As wafers

Etch Bath

Prepare

  1. Log onto CRESS.
  2. If system is off, press PWR on the ETCH BATH controller.
  3. The system will start in a holding status, press HOLD to release.
  4. Allow the bath temperature to stabilize at 40C. Approximately 15-20 minutes.
  5. Insert wafers in the either 3-inch or 4-inch wafer holder. Pieces should be locked in the basket and then the basket placed inside the 3-inch wafer holder.
  6. Don all PPE – apron, face shield and chemical gloves – before using the etch bath.
  7. Lift off the white tank lid and set aside.

Wet Etching

  1. With PPE on, slowly lower holder/basket into acid tank.
  2. Replace the white tank lid.
  3. Rinse and remove chemical gloves to operate etch bath controller.
  4. With chemical gloves off, press START on the controller to begin the timer. The default setting is 5 minutes. Or, manually time etch period.
  5. At the end of 5 minutes, press STOP/RESET to stop alarm.

Rinsing

  1. Don all the PPE before removing holder/basket from acid tank.
  2. Lift off the white tank lid and set aside.
  3. Go to QUICK DUMPRINSER procedures.

Quick Dump Rinser (QDR)

Start

  1. Gently lift clear lid of QDR and slide lid down into slot.
  2. While wearing PPE slowing lift wafer holder/basket from Etch Bath. Hold above tank to allow dripping of acid solution to stop before moving wafer holder/basket to QDR.
  3. Lower holder/basket into compartment of quick dump rinser (QDR).
  4. Gently lift clear lid of QDR and cover tank.
  5. Replace the white tank lid to the acid bath.
  6. Carefully rinse bench top surface to remove any acid drips.

Rinse

  1. Rinse and remove chemical gloves before operating controllers.
  2. Do not PWR offETCH BATH
  3. With chemical gloves off, press START on RINSER controller.

Fill/dump cycles continue until 10 cycles are completed or the water measures10M-Ohm.

Ends with a final fill and5-second pre-alarm

  1. Press STOP/RESET to stop alarm.

End

  1. Go to the drying procedures.

Technique #1: Manually holding wafer or piece with tweezers and blow dry with nitrogen gun.

Technique #2: For full wafers only. Automatically dry wafers by transferring rinsed wafers into holder for Verteq spin dryer. Follow operating procedures.

  1. Stored DAE wafer holders/basket in QDR
    Do not remove holders and use at other process benches.

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