1. Fabrication pH Electrode Using Lift-Off Method and Electrodeposition Presented by Na Zhang

2. What ’ s the Problem? How to create clear windows in the substrate? How to create clear windows in the substrate?

3. How to solve the problem? Lift-Off Method Lift-Off Method LOL-2000 (bottom) S -1813 Photoresist (top)

4. Electrodeposition

5. pH Sensitivity Electrode #1 03-12-04_630s_30s_ph678_1.bin

6. Electrode #5 03-12-05_630s_30s_ph678_1.bin

7. End

8. Reference Procedure 1) Clean substrate 2) Spin spacer layer LOL-2000 @ 3000 rpm for 200nm thickness 3) Bake 140 C on hot plate for 5 minutes 4) Spin resist layer S-1813 @ 4000 rpm for 1.3 um thickness 5) Bake 110 C on hot plate for 2 minutes 6) Expose through pattern mask, 45s @ 2.45 mW/cm2 (110 mJ/cm^2 nominally)at UV250 mask aligner, intensity measured using the 400nm probe. 15 s @ 10 mW/cm2 (150 mJ/cm^2 nominally) at UV400 mask aligner. 7) Develop in MF319 for 30 sec, CAREFUL agitation 8) Rinse in DI water 9) Blow dry CAREFULLY. 10) Ash at 50W 250mTorr Oxygen for 30 s 11) Deposit thin film 12) Lift off in NMP (Remover 1165)