https://nanyte.com/photoresists/lor-20b · last updated 2026-09-12
- Manufacturer
- MicroChem (MCC) — now Kayaku Advanced Materials
- Tone
- Not photoimageable (underlayer)
- Chemistry
- Ancillary (not photoimageable)
- Thickness
- 1.3–3.5 µm
- Exposure dose
- Not exposed — dissolves in developer
- Developer
- No specific commercial developer product is named for this grade; the datasheet states LOR/PMGI is compatible with both metal-ion-free (TMAH) and metal-ion-bearing developer chemistries.
- Applications
- Lift-off
Cross-checked — two independent extractions agree on the spin curve and the single-value figures.
- Substrate
- Underlayer
- Resist
- Exposed
Spin coating
Data points
| Series | rpm | µm |
|---|---|---|
| LOR 20B | 1000 | 3.5 |
| 1500 | 2.6 | |
| 2000 | 2.0 | |
| 2500 | 1.7 | |
| 3000 | 1.4 | |
| 3500 | 1.4 | |
| 4000 | 1.3 |
Values are the manufacturer’s starting points, not a guarantee — characterize on your own tool. Series digitized from a published figure are approximate (±10 %).
read from figure — the green filled-triangle trace legended LOR 20B on the 'Thickness vs. Spin Speed - LOR B Thick Series' chart, p.5. Seven plotted markers at 500 rpm intervals; no numeric table accompanies the chart.
- Most of the thickness swing happens in the first half of the sweep: 34,500 Å at 1000 rpm falls to 20,500 Å by 2000 rpm, then only to 13,000 Å by 4000 rpm.
- So a target near the thick end sits where the curve is steepest and thickness is most sensitive to speed and to dispense — worth confirming on a test wafer rather than reading off the chart.
- Coating parameters are published for the product line rather than per grade: 5 ml dispensed dynamically over 3-5 s onto a 150 mm wafer at 300-500 rpm, 10,000 rpm/s acceleration to a 3,000 rpm terminal speed, 45 s spin, with EBR PG for edge-bead and whisker removal.
- An irregularly shaped substrate needs a slower spin.
- Adhesion
- HMDS not required — "Primers, such as HMDS, are typically not required" when LOR/PMGI is used as recommended; the datasheet describes excellent adhesion across semiconductor substrates.
Soft bake
- Soft bake
- Not published — characterize on-tool
- Notes
- The prebake dries the film and fixes its dissolution and undercut rate, and no grade-specific temperature or time is published.
SOURCE: "Soft-Bake/Prebake Process" section and Figures 5a-5b, Kayaku…
"Soft-Bake/Prebake Process" section and Figures 5a-5b, Kayaku "LOR and PMGI Resists" technical data sheet, Rev. D (August 2023)
Exposure
LOR 20B is not photoimageable. It is not exposed at all — it is coated beneath an imaged top resist and undercut laterally during development. See the development step below.
Development
- Developer
- No specific commercial developer product is named for this grade; the datasheet states LOR/PMGI is compatible with both metal-ion-free (TMAH) and metal-ion-bearing developer chemistries.
- Developer family
- TMAH or buffered alkaline
Not published for this resist: Dilution, Time, Method, Rinse — characterize on-tool.
SOURCE: Product description, the LOR/PMGI process-flow section and the…
Product description, the LOR/PMGI process-flow section and the product selection guide, Kayaku "LOR and PMGI Resists" technical data sheet, Rev. D (August 2023)
Hard bake, etch & strip
- Stripper
- Remover PG — expect the long end of any strip time at this thickness.
- Storage
- Store upright in original sealed containers in a dry area between 4 and 27 °C (40-80 °F), away from ignition sources, light, heat, oxidants, acids and reducers. Do not use after the expiration date.
Not published for this resist: Hard bake, Descum, Etch resistance — characterize on-tool.
Where it's used
Practical notes from the datasheet
LOR 20B is a thick PMGI-based sacrificial underlayer from the fast-dissolving B series, spun beneath a conventional photoresist and never exposed. Underlayer thickness is chosen against the deposited film, not against the feature: the sacrificial layer has to be thick enough that the metal landing on the substrate and the metal landing on top of the imaging resist are genuinely disconnected, or the lift-off tears instead of releasing. At 1.30-3.45 µm this grade is aimed at depositions the sub-micron grades cannot break. The trade is that a thick, fast-dissolving film keeps undercutting for as long as the imaging resist above it is developing, so the ledge can travel further than intended under fine features — which is why the datasheet's own thick-film example pairs a 30-series underlayer with 20 µm lines rather than sub-micron ones. Prebake temperature remains the primary control, with develop time close behind.
Grades in this family
Other grades in the LOR B series line differ mainly in coating thickness:
Sources & disclaimer
- MicroChem (MCC) — now Kayaku Advanced Materials — LOR 20B datasheet (Rev. D, August 2023 (printed in the footer of every page)) · accessed 2026-09-10
Manufacturer datasheet values are starting points; optimal parameters depend on your substrate, equipment and environment. Product names and trademarks belong to their respective owners. NANYTE is not affiliated with the manufacturers listed. Last updated 2026-09-12.