Photolitho20231220

GM 1070 for thickness 25 um

Film masks: MP04-Lines with width 10/20/40 um, MP05-L-shape and Umbrella

Results: MP04-fine, 40 um line looks ok, 20 um line is narrower than mask, 10 um line is not successful.

MP05-bad, accidentally developed twice.

Notes from using hotplate:

1-Set Program 1 to 22°C is useless, during Pre-bake, after switching on, the temperature goes to 65°C very rapidly. It seems to skip Program 1 and go straight to Program S1

2-Alternative and useful: during Post-bake, I set Program S1 to be 5 sec@48°C, with ramp speed =2, (Program S2 to be 65°C, Program S2 to be 95°C), temperature rises slowly.

3-I also set Program S4 to be 18°C, with ramp speed = 6, but it cools down too slowly anyway. The best is to turn off the machine and take out wafers.

Steps:

Day 0,

Take out the GM 1070 aliquot from the fridge (NA)

Day 1,

Clean 2 wafers with isopropanol + plasma (2 mins)

Spin coat speed: 3100 rpm, 40 sec

Relax time: 1 hour.

Pre-bake: 15 min@65°C, 35 min @95°C.

Exposure dose: 155~310 mJ/cm2 (divide the number from the datasheet, 620, by factor 2 to 4)

Exposure time: 20% power, 25s

Delay after UV exposure: 10 min.

Post-bake: (5 sec@48°C), 15 min@65°C, 40 min @95°C.

Develop in PGMEA: 3 min

Hard Bake using VWR hot plate 2 hours@135°C

Interferometer