https://nanyte.com/photoresists/lor-1a · last updated 2026-09-12
- Manufacturer
- MicroChem (MCC) — now Kayaku Advanced Materials
- Tone
- Not photoimageable (underlayer)
- Chemistry
- Ancillary (not photoimageable)
- Thickness
- 0.1–0.2 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 1A | 1000 | 0.16 |
| 1500 | 0.12 | |
| 2000 | 0.10 | |
| 2500 | 0.10 | |
| 3000 | 0.09 | |
| 3500 | 0.08 | |
| 4000 | 0.08 |
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 blue filled-diamond trace legended LOR 1A on the 'Thickness vs. Spin Speed - LOR A Thin Series' chart, p.5, the lowest of the three traces. Seven plotted markers at 500 rpm intervals; no numeric table accompanies the chart.
- The whole grade lives between 810 and 1,580 Å, so the entire spin sweep buys under 80 nm of thickness and the curve is flat from about 2500 rpm onward.
- Spin speed is a trim here, not a control — pick the grade for the thickness you want and use speed to fine-tune.
- 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 1A 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 1A is the thin end of the whole LOR range — a PMGI-based sacrificial film spun under a conventional photoresist and never exposed itself. At 810 to 1,580 Å it is thinner than most of the metal anyone lifts off with it, which is the point rather than a limitation: the underlayer only has to out-dissolve the imaging resist far enough to break the deposited film at its edge, and every extra nanometre of sacrificial layer costs resolution. That makes this the grade for fine features and thin depositions, where a micron-scale underlayer would undercut straight through the pattern. The A series dissolves more slowly than B or C for the same prebake, which is the other half of why it suits fine work — the ledge opens gradually and the process window is wider. Nothing here is exposed, so there is no dose, no tone and no post-exposure bake to set; 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 1A 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.