https://nanyte.com/photoresists/lor-2a · last updated 2026-09-12
- Manufacturer
- MicroChem (MCC) — now Kayaku Advanced Materials
- Tone
- Not photoimageable (underlayer)
- Chemistry
- Ancillary (not photoimageable)
- Thickness
- 0.1–0.3 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 2A | 1000 | 0.27 |
| 1500 | 0.20 | |
| 2000 | 0.18 | |
| 2500 | 0.16 | |
| 3000 | 0.15 | |
| 3500 | 0.14 | |
| 4000 | 0.13 |
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 red filled-square trace legended LOR 2A on the 'Thickness vs. Spin Speed - LOR A Thin Series' chart, p.5, the middle of the three traces. Seven plotted markers at 500 rpm intervals; no numeric table accompanies the chart.
- A shallow curve across the whole sweep — 2,650 Å at 1000 rpm to 1,280 Å at 4000 — so the grade spans barely a factor of two and speed is a fine trim rather than a coarse control.
- It tracks roughly midway between the 1A and 3A traces at every speed, which is the practical way to place it: if a target falls between those two grades' ranges, this is the grade rather than a spin-speed compromise on either.
- 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.
- 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 2A 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. EBR PG removes edge beads and whiskers and is also an effective spin-bowl cleaner and a rework solvent for unbaked wafers.
- 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 2A is a PMGI-based sacrificial underlayer from the slow-dissolving A series, spun beneath a conventional photoresist and never exposed itself. Its job is purely geometric: the underlayer has to out-dissolve the imaging resist far enough that the metal landing on the substrate and the metal landing on top of the resist never join, and it has to do that without the ledge running so far under the pattern that fine features collapse. At 0.128-0.265 µm this grade is aimed at thin depositions — thin enough that LOR 1A cannot reliably break the film, thick enough that LOR 3A would be generous. The A series is the slower of the three dissolution families, which widens the process window at the cost of needing a cooler or longer develop to reach the same undercut. Nothing here is exposed, so there is no dose, no tone and no post-exposure bake; prebake temperature and develop time do all the work.
Grades in this family
Other grades in the LOR A series line differ mainly in coating thickness:
Sources & disclaimer
- MicroChem (MCC) — now Kayaku Advanced Materials — LOR 2A 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.