Lift-off DUV Lift-off: LOR Underlayers
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LOR10A - ~1µm underlayer
| Dehydration bake | ≥150°C | 5 min |
| Spin LOR10A | Recipe 5: 3000 rpm | See datasheet for spin curves |
| Backside clean | Spin/spray: Remover PG / Acetone / IPA | required for ASML DUV |
| Softbake | 200°C on lift-pins.
Use recipe: "STD 200C 5min" |
5 min |
| Spin LOR10A | Recipe 5: 3000 rpm | |
| Backside clean | Spin/spray: Remover PG / Acetone / IPA | |
| Softbake | 200 C on pins. Use recipe 200 C 5 min. | 5 min |
| Spin UV6-0.8 | Recipe 6 3500 rpm | |
| Softbake | 135C | 1 min |
| Backside clean | Spin/spray Acetone/IPA | |
| Expose | ~21-25mJ - you may need to optimize
Focus = +0.2 |
ASML |
| Post exposure bake | 135C | 90 sec |
| Develop AZ726MIF | no agitation | usually > 2.5min |
| Microscope Inspect | Check undercut | Typ. ~1-2µm |
Contributed by Alex Spott.
LOR30C - ~30µm underlayer
- Dehydrate (O2 plasma or 150°C, 2 min+), no adhesion promoter
- Spin LOR30C at various speeds depending on thickness desired
- 180°C, 4 min
- Spin/bake imaging layer - according to Imaging PR recipe
- Expose ASML
- Post-bake imaging layer - according to Imaging PR recipe
- Develop AZ 300MiF - varies:
- Develop times range between 2 min to as long as 6 or 8 minutes (it's consistent for the same mask and same materials, but varies for process steps, topography, and materials).
- Strips in 80C NMP 20–30 min
Pros: Thick in a single layer, excellent coverage for tall features, varying topography, and filling vias. Rarely has cracking issues, no ramp baking required, typically minimal bubbles from feature corners.
Cons: High and uncontrollable undercut. You can't switch to flood expose / 101A like you can with PMGI so you're stuck with the undercut you get whenever it's done developing. Not suitable for close features.
Contributed by Alex Spott.