Semiconductor Laboratory














Spin coater

Spin coating is a process where a thin polymer layer is deposited on a flat substrate by dropping the liquid polymer on the substrate and spinning it very fast. Read the Introduction to Spin Coating from Chemat Scientific then read the Spin Coater KW-4A Manual.

Operating instructions from the KW-4A manual

  1. Preheat the hot plate for the baking step after spinning the resist.
  2. Select and install a sample chuck which fits the size of the substrate to be coated. Match the notch at the bottom of the chuck with the pin on the center shaft, and mount the chuck firmly on the spinning shaft. The substrate size should always be bigger than the size of the chuck which you are using. (Recommended ¼ inch bigger than the chuck’s size). If not, the coating solution will easily be sucked into the vacuum system.
  3. Line the bowl of the spinner with aluminum foil to catch the resist that will be sprayed off.
  4. Turn the "Power" switch on. Press the "Control" button one time only.
  5. Set spin cycle time and speeds. Speed I is the low speed and the spin cycle time for this speed range should be set with Timer I. (Drop to photoresist on at low speed. Use 500 rpm and 5 seconds on the timer. This gives you 5 seconds to drop the photo resist before the fast spinning starts.) Speed II is for high speed and the spin cycle time for the speed range should be set with Timer II. (For AR-U 4040 resist use 4000 rpm for 60 s.)
  6. Use tweezers to place the substrate on the sample chuck and make sure the substrate is centered before spinning operation begins.
  7. Press the "Vacuum" button once to turn on the vacuum.
  8. Have the resist ready in an eyedropper. Press the "Start" button to start the spinning operation. Drop the resist on the substrate while it is spinning at the low speed. After the time set on Timer I, the spinner will speed up to Speed II and spin at high speed for the time set on Timer II.
  9. Place the bowl cover over the bowl. Lower the glass front of the fume hood.
  10. When the cycle ends, press "Vacuum" to turn the vacuum off and release the sample.
  11. Remove the bowl cover.
  12. Repeat steps 3-11 for more samples.
  13. Turn the "Power" switch off when you are finished.
  14. Remove the aluminium foil and let it to dry under the fumehood before discarding it in the "contaminated laboratory waste." If there is resist on the work surface, use papertowels and isopropanol to clean it up. Put the used paper towels in the paper waste container under the fumehood.
  15. When remowing your gloves, turn them inside out and throw them into the waste contaimer (Restmull). If there is a lot of resist or solvents on the gloves, leave them to dry under the fumehood in the "comtaminated laboratory waste."

Safety Precautions

  1. Wear gloves and safety glasses to keep the resist from getting on your skin or into your eyes.
  2. DO NOT touch or hold the shaft or chuck while rotating. Severe injury may result.
  3. The substrate may fly off the rotation chuck. Wear safety glasses. Lower the glass front of the fume hood.
  4. Dangerous electrical potentials are present inside the instrument. Unplug before opening the instrument.
  5. Motor brushes and switch contacts may produce sparks. DO NOT use the laboratory spinner in the presence of any explosive atmosphere.