Difference between revisions of "A Simplified Version"

Latest revision as of 15:44, 8 March 2021

The simplest SU8 photolithography process [Simple Version]

The process is for 25um thickness. The photo resist is GM1070 series. The data for different thickness, please just check the manual.

1. Take the SU8 out of the fridge, keep it in dark until it goes back to room temperature.
2. Room 129: Turn on the hot plate, set the temperature as 150 degree. Open the Nitrogen valve.
3. Clean the wafer with Acetone and Isopropanol, remove the liquid with N2 air gun. Close the nitrogen valve.
4. Dry the wafer on the hot plate at 150 degree for 10 mins. Wait the temperature cool down to room temperature, then put the wafer on the spin.
5. Turn off the light in the room 129 and turn on the yellow light in the bench. Pure the SU8 on the wafer, try to avoid bubbles.
6. Set the spin as 3100rpm for 40 seconds. Acceleration is 100rpm/s. Start it.
7. Relax the wafer on the spin for 10 mins.
8. Put the wafer on the hot plate for prebake. 15mins at 65°C, 35mins at 95°C. The temperature raises at 2°C/min. Wait until the temperature goes back to room temperature. (When you start the prebake, covered the wafer, you could turn on the light.)
9. Turn off the light in room 127, turn on the yellow light. Put the wafer in the KUB exposure holder. Put the pattern on the wafer (print side towards the wafer). Clean the cover glass and put it on the pattern. Set the thickness as 500um. 100% continuous exposure for 26.6 seconds. Start exposure.
10. Relax the wafer for 10 mins.
11. Post bake: 15mins at 65°C, 40mins at 95°C. 2°C/mins. Then wait for cooling. (You could turn on the light, when you start post bake.)
12. Turn off the light in room 128, turn on the yellow light in air flow bench. Open the nitrogen valve, Get PGMEA and Isopropanol ready. Get timer ready.
13. Put the wafer in PGMEA for developing 3mins. Then rinse with isopropanol. Dry it with nitrogen air gun. Check your pattern with microscope (yellow light). You don’t need yellow light any more.
14. Hard bake: 135°C for 2 hours.
15. Done!

Spinner, Hot Plate,UV kub program

Spin Coating

Buttons: D, E, C

D = Enter, E= Edit, C = Confirm/Finish/Exit

Parameters:

Start Delay: 3S

Dwell = Spinning Time

Ramp= Acceleration Time

Speed: rpm/s - For example, 400 rpm/s, 1700 rpm/s

1. Power on, Manual

Two Step Settings:

Step 1:

Program press D to set -> D -> [Program Menu?] -> D-> [Edit start/stop?]-> D-> [Edit Step 1]-> E-> [Edit step 1 Speed: 400]-> D->

[Edit step 1 Dwell: 20]-> D-> [Edit step 1 Ramp: 100]-> D -> [Edit step 1 o/ps:] -> C-> Program press D to set

Step 2:

Program press D to set -> D-> [Edit step 1] -> D-> [Edit step 2] -> E -> [Speed: 1700] -> D-> [Edit step 2 Dwell: 40]-> D->

[Edit step 2 Ramp: 100]-> D-> [Edit step 2 o/ps:] -> C-> Program press D to set

Attention: Step 3 [No settings] – Test whether has part 3

Turn on the vacuum pump to hold the wafer on the spinner, includes the valve below the bench.

Volume： Add more volume than the minimum required. Not necessarily to be accurate.

Blue button to start the spin coating.

Hot Plate

Red Numbers: Present Temperature, Green Numbers: Set point temperature

Buttons:

P, Arrows: UP and Down

P: change settings and confirm,

UP and Down: change numbers.

Always press P to change and confirm settings.

P --->Temperature: Pr.51 65->P --->Time: Pr.t1 15->P --->Temperature: Pr.52 95 ->P --->Time: Pr.t2 99.99->P ---->Temperature: Pr.53 95->P ---->Time: Pr.t2 20->P

Start the program:

Press and hold U till the greed dot shows, then release. (behind the green number)

UV kub program

1. Back of the machine, power on

2. On/off front, On

3. Touch screen, load the wafer. – click and find out

Load sequence:

Wafer- mask- glass

Bottom is wafer, mask in the middle and top is the glass plate.

Thickness: 500 + SU8 thickness

Distance: 0

V: confirm, C: clear (touch screen - click)

Continue

New cycle, Continuous

Exposure time/ Duration:

T (s) = Typical exposure dose (mJ/cm2)/23.4

power = 100%

Insolate – start to UV illumination. Red button is for force to stop.

Done

Off the front screen, then power off at the back.