Photoresist Recipes

Photoresist should have some time to warm up before using.

Always remember to put them back in the fridge!!

g-line wavelength 436 nm; i-line wavelength 365 nm; I think our litho tools are i-line.

• AZ 5214, cover slide sample adhesion

  • 6 drops of PR on cover slide
  • Spin 1min @ 1K RPM
  • No bake, place the sample to be mounted on the center of the cover slide quickly after the spin finishes
  • Gently push the sample corners as the PR dries (should be able to see rainbows from the backside of the cover slide)

• AZ 5214, positive

  • Spin 1min @ 3K RPM (around 1.7 um thickness)
  • Bake 1min @ 110 degree C
  • Exposure 13s @ CL1 (7.5 mW)
  • Develop 45s @ AD10/MF26A (develop time may vary?)

• AZ 2020, negative

  • Spin 1min @ 4.5k RPM (around 2um thickness)
  • Bake 1min @ 110 degree C
  • Exposure 5.5s - 6s @ CL1 (7.5 mW)
  • Bake 1min @ 110 degree C
  • Develope 30s @ AD10/MF26A 

• SPR 220, positive, datasheet

  • Courtesy of Prof. Ruochen Lu

  • Spin 1min @ 3k RPM (around 5um thickness)
  • 1st pre-bake 2min @ 60 degree C
  • 2nd pre-bake 1min @ 115 degree C 
  • Exposure 45s @ CL1 (7.5 mW). This is about 340 mJ/cm^2 dose.
  • Develope 2min @ MF26A

• Photolithography for Thermal Deposition

  Note: This recipe is built for Cr/In (40/500 nm) deposition at Denton evaporator. It is different from typical e-beam

• evaporation becaus

• e of the use of a lift-off resist (LOR, PMGI SF6) and using PG remover (instead of a Kwikstrip remover). It takes about 20 minutes for total lift-off

  Spin-coating and pre-baking

  1. Clean the sample in acetone and IPA
  2. Spin-coat PMGI-SF6 (LOR) on the sample at 2.5K-3K (RPM) for 40 seconds
  3. Bake the sample at 190^o C for 5 minutes
  4. Spin-coat AZ-5214 on the sample at 3K (RPM) for 1 min
  5. Bake the sample at 110^o C for 1 minute
  6. Use a foam Q-tip dipped in acetone for edge-bead removal

  
  

  Exposure and Developing

  1. Expose the sample to UV light for 15 seconds (365 nm)
  2. Develop the sample in AD-10 for 2:30 minutes (30 sec for the PR and 2 min to develop and undercut the LOR) – Be sure to do an agitated developing
  3. Descum the sample for 1 min at Oxford RIE (20 sccm O₂ 80 RF power)
• NR9-500p negative resist

Spin at 3k RPM for 40 sec
Pre-bake at 70C for 3 min
Expose 12 sec MA6 Cl1
Post-bake at 100C for 3 min
Develop for 10 sec in MF-26A / AD10