https://nanyte.com/photoresists/az-nlof-2070 · last updated 2026-07-26
- Manufacturer
- Merck
- Tone
- negative
- Chemistry
- Chemically amplified
- Thickness
- 5.3–11.8 µm
- Developer
- AZ 300MIF
- Applications
- Lift-off · Etch mask
Cross-checked — two independent extractions agree on the spin curve and the single-value figures.
- Substrate
- Resist
- Exposed
Spin coating
Data points
| Series | rpm | µm |
|---|---|---|
| AZ nLOF 2070 | 500 | 12 |
| 1000 | 11 | |
| 1500 | 9.2 | |
| 2000 | 7.8 | |
| 2500 | 7.0 | |
| 3000 | 6.3 | |
| 3500 | 5.8 | |
| 4000 | 5.3 |
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, "SPIN CURVES (150mm Silicon)", p.1 of AZ nLOF 2000 Series Technical datasheet (Rev. 03/21) — chart plots three grades (nLOF 2070 red, nLOF 2035 yellow, nLOF 2020 blue) with an explicit color-coded legend; nLOF 2070 identified by its red 'nLOF 2070' legend entry (top curve, highest thickness at every speed) and cross-checked against the grade-specific 7.0 µm reference process (p.5, which names 'AZ nLOF 2070 (330cPs)' explicitly).
- Unlike the ambiguous combined charts flagged elsewhere in this recipe set, this chart carries an explicit color-coded legend naming each of the three plotted grades individually (nLOF 2070, nLOF 2035, nLOF 2020), and the identification is cross-checked against this datasheet's own grade-specific reference-process tables (p.3, p.5), which name the exact grade and viscosity (cPs) used for each nominal film thickness.
- Still a figure read, not a numeric table, so visual QC is required.
- No dispense volume, spin ramp, or edge-bead detail is published in this datasheet.
- Adhesion
- HMDS recommended — Oxide-forming substrates (e.g. Si) should be HMDS primed prior to coating (PROCESS CONSIDERATIONS > SUBSTRATE PREPARATION, p.8).
- Rehydration
- None required — p.1 TYPICAL PROCESS states 'Rehydration Hold: None', consistent with this being a chemically amplified resist, not a DNQ resist.1
Soft bake
- Soft bake
- 110 °C (100–110 °C) · 1.5 min · hotplate
- Notes
- Reference process for the 7.0 µm nLOF 2070 film (p.5): 110°C, 90 s, direct contact hotplate — longer than the 60 s used for the thinner 2.0 µm (nLOF 2020) and 3.5 µm (nLOF 2035) grades, consistent with a thicker coat needing more bake time to drive off solvent.
SOURCE: EXAMPLE PROCESS (7.0µm Film Thickness on Si), p.5 of AZ nLOF 2000 Series Technical datasheet (Rev. 03/21)
Exposure dose
The 7 µm process is dosed to a CD target, not to a fixed number: 174, 186 and 198 mJ/cm² i-line gave 4.45, 4.84 and 5.31 µm bottom CD on 7 µm dense mask lines. None of the three is named as the nominal. Run a dose array on your own tool to land the working dose.
- Post-exposure bake
- 110 °C (100–115 °C) · 1.5 min
Not published for this resist: Dose at 365 nm, Dose at 405 nm — characterize on-tool.
Development
- Developer
- AZ 300MIF
- Dilution
- undiluted (ready-to-use 0.26N / 2.38% TMAH developer; no dilution ratio stated)
- Time
- 2 min
- Method
- puddle
- Rinse
- Not published — characterize on-tool
- Developer family
- TMAH-based
SOURCE: EXAMPLE PROCESS (7.0µm Film Thickness on Si), p.5 of AZ nLOF…
EXAMPLE PROCESS (7.0µm Film Thickness on Si), p.5 of AZ nLOF 2000 Series Technical datasheet (Rev. 03/21): 'AZ 300MIF, 2 x 60 second puddles'
Hard bake, etch & strip
- Stripper
- AZ 400T or AZ Remover 770 (solvent-based removers), recommended per PROCESS CONSIDERATIONS > STRIPPING, p.8 of AZ nLOF 2000 Series Technical datasheet.
Not published for this resist: Hard bake, Descum, Etch resistance, Storage — characterize on-tool.
SOURCE: PROCESS CONSIDERATIONS > HARD BAKE, and HARD BAKE STABILITY…
PROCESS CONSIDERATIONS > HARD BAKE, and HARD BAKE STABILITY for Large Pads in AZ nLOF™ 2070 (7.0µm Film Thickness), p.8 of AZ nLOF 2000 Series Technical datasheet (Rev. 03/21)
Where it's used
Practical notes from the datasheet
AZ nLOF 2070 is the ~7 µm grade of AZ's nLOF 2000 series, a chemically amplified negative photoresist purpose-built to replace older image-reversal and multi-layer lift-off processes with a single expose/PEB/develop flow and a clean undercut sidewall. As with the whole series, the post-exposure bake is required, not optional, unlike the DNQ positive resists elsewhere in this recipe set, and CD is sensitive to PEB temperature (roughly <0.04 µm/°C per the datasheet's series-level guidance). Unlike thick DNQ positive resists it needs no rehydration wait after softbake, and softbake/PEB both scale up to 90 s at this thickness versus 60 s for the thinner 2020/2035 grades. It develops in AZ 300MIF (0.26N/2.38% TMAH) via two 60-second puddle cycles rather than one. Printed features are thermally stable well above 150°C — the datasheet specifically demonstrates hard-baking large 7 µm nLOF 2070 pads at 115-130°C with stable edge profiles — which is what lets nLOF's negative-tone undercut survive a subsequent metal evaporation and lift-off step. The datasheet explicitly does not recommend nLOF 2000 series resists for use on copper substrates.
Grades in this family
Other grades in the AZ nLOF 2000 Series line differ mainly in coating thickness:
| Grade | Thickness | Exposure dose |
|---|---|---|
| AZ nLOF 2020 | 1.6–4.6 µm | 66 mJ/cm² @ 365 nm |
| AZ nLOF 2035 | 3–6.1 µm | 80 mJ/cm² @ 365 nm |
| AZ nLOF 2070 (this page) | 5.3–11.8 µm | — |
Troubleshooting
Common failure modes for AZ nLOF 2070, answered from the manufacturer's datasheet and application notes. These are starting points — your substrate, tooling and environment shift the specifics, so calibrate on-tool.
How do I get an undercut lift-off profile with AZ nLOF 2070?
AZ nLOF 2070 is a chemically amplified negative resist that forms the undercut lift-off sidewall directly from one expose/PEB/develop flow, replacing older image-reversal and multi-layer schemes. The PEB is required for imaging. Because printed features stay thermally stable well above 150°C, the ~7 µm undercut survives a subsequent metal evaporation and lift-off.
SOURCE: AZ nLOF 2000 Series Technical datasheet (Rev. 03/21) — EXAMPLE PROCESS (7.0µm on Si), p.5, and HARD BAKE, p.8
Why does AZ nLOF 2070 need longer bakes and develop than the thinner grades?
It coats ~7 µm, so both soft bake and PEB scale up to 110°C/90 s (versus 60 s for the 2.0 and 3.5 µm grades) to drive off solvent and complete imaging through the thicker film, and develop is two 60 s AZ 300MIF puddles (120 s total) rather than one — a thicker coat simply needs more time to clear.
SOURCE: AZ nLOF 2000 Series Technical datasheet (Rev. 03/21) — EXAMPLE PROCESS (7.0µm on Si), p.5
What exposure dose does AZ nLOF 2070 need?
The 7.0 µm reference process states only 'various doses' at i-line (365 nm) — no single nominal. Its bottom-CD sweep for 7.0 µm dense lines reads 174 mJ/cm² → 4.45 µm, 186 → 4.84 µm and 198 → 5.31 µm bottom CD, so dose sets the undercut; pick the point that gives your target CD and confirm on-tool. No 405 nm dose is published.
SOURCE: AZ nLOF 2000 Series Technical datasheet (Rev. 03/21) — EXAMPLE PROCESS (7.0µm on Si), p.5
Can AZ nLOF 2070 be hard baked, and how stable is the pattern?
Printed features are thermally stable well above 150°C. The datasheet demonstrates hard-baking large 7 µm nLOF 2070 pads at 115, 120, 125 and 130°C with stable edge profiles across that range, though no single hold time or recommended temperature is named. This thermal stability is what lets the negative-tone undercut survive metal evaporation and lift-off.
SOURCE: AZ nLOF 2000 Series Technical datasheet (Rev. 03/21) — HARD…
AZ nLOF 2000 Series Technical datasheet (Rev. 03/21) — HARD BAKE / HARD BAKE STABILITY for Large Pads in AZ nLOF 2070, p.8
Sources & disclaimer
- Merck — AZ nLOF 2070 datasheet (Rev. (03/21)) · accessed 2026-07-10
- TYPICAL PROCESS, p.1, and EXAMPLE PROCESS (7.0µm Film Thickness on Si), p.5, of AZ nLOF 2000 Series Technical datasheet (Rev. 03/21)
- Gerlt et al.. Reduced Etch Lag and High Aspect Ratios by Deep Reactive Ion Etching (DRIE). Micromachines (2021). doi:10.3390/mi120505427.2 µm nLOF 2070 DRIE mask; documents its slightly angled sidewalls
- Huang et al.. Fabrication of metal air bridges for superconducting circuits using two-photon lithography. Applied Physics Letters (2025). doi:10.1063/5.02717887 µm nLOF 2070 air-bridge lift-off for superconducting qubit circuits, direct-write patterned
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 2026-07-26.