https://nanyte.com/photoresists/az-40xt · last updated 2026-09-28
- Manufacturer
- Merck KGaA, Darmstadt, Germany
- Tone
- positive
- Chemistry
- Chemically amplified
- Thickness
- 20–60 µm
- Exposure dose
- 400 mJ/cm² at 365 nm (on Si; 900 mJ/cm² on Cu (40 µm))
- Developer
- AZ 300MIF
- Applications
- Electroplating / molding · High aspect ratio · Etch mask
Human-verified — checked against the manufacturer's datasheet by a person.
- Substrate
- Resist
- Exposed
Spin coating
Data points
| Series | rpm | µm |
|---|---|---|
| AZ 40XT-11D | 1000 | 65 |
| 1500 | 46 | |
| 2000 | 35 | |
| 2500 | 29 | |
| 3000 | 25 | |
| 3500 | 21 | |
| 4000 | 18 |
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 CURVE (200mm Silicon)", p.1 of AZ 40XT-11D Photoresist technical datasheet (Rev. 7/2016) — a single curve for one product, no multi-grade ambiguity
- Chart conditions (p.1, in-figure annotation): coat by hand dispense at 30 rpm, spin 1000-3000 rpm for 20 seconds, then bake 125°C/7 min. As an 'ultra-high viscosity' material (p.7, PROCESS CONSIDERATIONS > COATING), careful control of nozzle height, dispense rate, dispense volume, and spin parameters is needed to avoid bubbles/voids
- hand-coating should use a beaker with an integrated pour spout (a pipette or dropper is explicitly NOT recommended), pouring close to the wafer surface after letting any bubbles dissipate.
- The datasheet itself notes final film thickness depends on the combination of spin speed AND spin time, not spin speed alone, so the plotted curve (spun to equilibrium) is only one data point in that space.
- Adhesion
- HMDS recommended — Oxide-forming substrates (e.g. Si) should be HMDS primed prior to coating AZ 40XT (PROCESS CONSIDERATIONS > SUBSTRATE PREPARATION, p.7).
- Rehydration
- None required — a key differentiator from thick DNQ resists, which do need a post-softbake rehydration hold. p.1 (APPLICATION) states 'No post bake rehydration delays required', and every reference process in this datasheet lists 'Post Bake Delay: None' (p.2, p.4, p.6).1
Soft bake
- Soft bake
- 125 °C (115–125 °C) · 7 min · hotplate
- Notes
- p.1 TYPICAL PROCESS gives "Bake: 125C, 7 min." (420 s) for the spin-curve chart's coating condition. The same bake runs in all three reference processes (40 µm on Si, 40 µm on Cu, 45 µm on Cu): a three-stage ramped/proximity bake at 125°C — 120 s at a 1.27 mm gap, 120 s at 0.63 mm, then 180 s in full contact, 420 s total. It is a staged proximity ramp, not a single flat-contact soak. Soft-bake temperature should generally sit in the 115-125°C range, and ramping the temperature or standing the wafer off the plate is required to stop the film bubbling as solvent leaves this very thick coat.
SOURCE: Reference Process tables, p.2, p.4, p.6 of AZ 40XT-11D Photoresist technical datasheet (Rev. 7/2016)
Exposure dose
The manufacturer publishes 400 mJ/cm² at 365 nm (on Si; 900 mJ/cm² on Cu (40 µm)). Dose scales with film thickness and depends on your optics, so treat it as a starting point and run a dose array.
- Dose at 365 nm
- 400 mJ/cm² (on Si; 900 mJ/cm² on Cu (40 µm))
- Dose at 405 nm
- Not published — characterize on-tool
- As published
- 400 mJ/cm² i-line is the reference dose for a 40 µm film on silicon. Copper changes it a lot: 900 mJ/cm² for the same 40 µm, and 1000 mJ/cm² for a 45 µm plating film.
- Post-exposure bake
- 105 °C (100–110 °C) · 2 min
SOURCE: REFERENCE PROCESS (40µm Film Thickness on 200mm Si), p.2-3 of AZ 40XT-11D Photoresist technical datasheet (Rev. 7/2016)
Development
- Developer
- AZ 300MIF
- Dilution
- undiluted (ready-to-use 0.26N / 2.38% TMAH developer; no dilution ratio stated)
- Time
- 4 min
- Method
- puddle
- Rinse
- Not published — characterize on-tool
- Developer family
- TMAH-based
SOURCE: REFERENCE PROCESS (40µm Film Thickness on 200mm Si), p.2 of AZ…
REFERENCE PROCESS (40µm Film Thickness on 200mm Si), p.2 of AZ 40XT-11D Photoresist technical datasheet (Rev. 7/2016): '4 x 60 second puddles', matching the p.1 front-page demo caption 'AZ 300 MIF Develop (240s)'
Hard bake, etch & strip
- Hard bake
- 80 °C (80–85 °C) · 5 min (optional — not needed for plating)
- Stripper
- AZ 400T (solvent-based remover), recommended generically per PROCESS CONSIDERATIONS > STRIPPING (p.7). Demo strip conditions vary between reference processes: AZ 400T @ 55°C/10 minutes (p.4, 40 µm Cu-plating process) vs. AZ 400T @ 70°C/5 minutes (p.6, 45 µm high-speed Cu-plating process).
- Storage
- Combustible liquid; store in sealed original containers in a well-ventilated, dry area away from heat, light, oxidizers, reducers, and sources of ignition. Recommended storage temperature 30-55°F (as printed, p.8, STORAGE).
Not published for this resist: Descum, Etch resistance — characterize on-tool.
SOURCE: 20µm Studs Post Cu Plate and Strip, p.4, and PROCESS…
20µm Studs Post Cu Plate and Strip, p.4, and PROCESS CONSIDERATIONS > HARD BAKE, p.7, of AZ 40XT-11D Photoresist technical datasheet (Rev. 7/2016)
Where it's used
Practical notes from the datasheet
AZ 40XT-11D is a chemically amplified thick positive resist, the odd one out among AZ's thick-film positive resists: unlike the DNQ resists (P4620, 10XT), it requires NO post-softbake rehydration wait (every reference process here lists 'Post Bake Delay: None') but DOES require a post-exposure bake, and skipping that PEB is the classic failure mode for this material — without it the pattern will not image properly. Both softbake and PEB are run as ramped/proximity bakes (three discrete stages at decreasing hotplate proximity) rather than a single flat contact bake, specifically to avoid solvent-outgassing bubbles in these very thick (20 to over 60 µm) single coats. It develops in AZ 300MIF, a 0.26N (2.38%) TMAH developer, applied as puddle cycles rather than a single immersion step. Exposure dose scales sharply with substrate: roughly 400 mJ/cm² at 365 nm for a 40 µm coat on silicon versus 900-1000 mJ/cm² for a comparable coat on copper. Hard bake is generally unnecessary for plating use and, when applied, should stay in the 80-85°C range to avoid thermally distorting the pattern.
Troubleshooting
Common failure modes for AZ 40XT-11D, 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.
Why does my AZ 40XT film bubble during soft bake?
The solvent is flashing off too fast. The datasheet says a ramped temperature or plate proximity is required at soft bake to prevent the film bubbling from rapid solvent evaporation, within a 115–125 °C window. Its reference bake at 125 °C steps the wafer down: 120 s at a 1.27 mm gap, 120 s at 0.63 mm, then 180 s in contact. Without proximity pins, MicroChemicals suggests contact-hotplate ramps such as 60 … 80 … 100 °C, or a ramped convection oven.
SOURCE: AZ 40XT-11D Photoresist technical datasheet (Merck, Rev…
AZ 40XT-11D Photoresist technical datasheet (Merck, Rev. 7/2016) — Process Considerations: Soft Bake, p.7; Reference Process (40 µm on Si), p.2; Photolithography Trouble Shooter (MicroChemicals) — Bubbles in the Resist Film After the Softbake: Volatile Resist Components, p.2
I see voids in AZ 40XT straight after coating — how should I dispense it?
Start with the dispense. The datasheet says nozzle height, dispense rate, volume and spin parameters all need optimising to avoid bubbles and voids with a resist this viscous. For hand coating, pour a small amount into a beaker with a spout, wait for bubbles to dissipate, then pour close to the wafer surface; a pipette or dropper is not recommended. Thickness is set by spin speed and spin time together (the spin curve uses 20 s at 1000–3000 rpm on 200 mm), so fix both.
SOURCE: AZ 40XT-11D Photoresist technical datasheet (Merck, Rev…
AZ 40XT-11D Photoresist technical datasheet (Merck, Rev. 7/2016) — Process Considerations: Coating, p.7; Spin Curve (200 mm Silicon), p.1
AZ 40XT is exposed but hardly develops — what did I miss?
Check the PEB first. AZ 40XT is chemically amplified, and the datasheet flags the PEB as required for proper imaging; MicroChemicals' trouble shooter adds that without it the development rate is almost zero. The general rule is 100–110 °C, and the reference process ramps it at 105 °C: 10 s at 1.3 mm, 10 s at 0.6 mm, then 80 s in contact. Exposure needs 365 nm energy. A rehydration hold, which thick DNQ resists need, is not required for AZ 40XT.
SOURCE: AZ 40XT-11D Photoresist technical datasheet (Merck, Rev…
AZ 40XT-11D Photoresist technical datasheet (Merck, Rev. 7/2016) — Typical Process, p.1; Reference Process, p.2; Process Considerations: Exposure, Post Expose Bake, p.7; Photolithography Trouble Shooter (MicroChemicals) — Chemically Amplified Resists, p.9; Rehydration Sufficiently Long?, p.6
My 40 µm AZ 40XT process works on Si but underexposes on Cu — why the big dose change?
The datasheet uses very different doses for the same 40 µm film: 400 mJ/cm² on Si against 900 mJ/cm² on Cu (Suss MA-200, 20 µm proximity gap), and 1000 mJ/cm² for 45 µm on Cu. Develop changes too: 4 × 60 s puddles on Si, 3 × 40 s on Cu. On Si, 40 µm lines stay within ±10 % of target from roughly 250 to 700 mJ/cm² (exposure latitude over 90 %). As a positive resist, more dose narrows lines and widens holes, so run a dose series on your actual substrate.
SOURCE: AZ 40XT-11D Photoresist technical datasheet (Merck, Rev…
AZ 40XT-11D Photoresist technical datasheet (Merck, Rev. 7/2016) — Reference Process (40 µm on Si), p.2; Process Windows on Si, p.3; Reference Process (40 µm on Cu), p.4; Process Windows on Cu, p.5; High Speed Cu Plating Performance, p.6
Can I hard bake AZ 40XT before plating the way I would a thick DNQ resist?
Only gently. The datasheet keeps AZ 40XT hard bakes at 80–85 °C to keep thermal distortion minimal, and says a hard bake is typically not needed for plating at all; it may help adhesion in wet etch and pattern stability in dry etch. Of its two Cu plating examples, the 20 µm stud run bakes at 80 °C for 5 min before 50 min at 1.5 ASD, and the high-speed run lists no hard bake. Strip with AZ 400T; the examples use 55 °C for 10 min and 70 °C for 5 min.
SOURCE: AZ 40XT-11D Photoresist technical datasheet (Merck, Rev…
AZ 40XT-11D Photoresist technical datasheet (Merck, Rev. 7/2016) — Process Considerations: Hard Bake, Stripping, p.7; 20 µm Studs Post Cu Plate and Strip, p.4; High Speed Cu Plating Performance, p.6
Sources & disclaimer
- Merck KGaA, Darmstadt, Germany — AZ 40XT-11D datasheet (Rev. 7/2016) · accessed 2026-07-10
- TYPICAL PROCESS, p.1, and REFERENCE PROCESS tables, p.2, p.4, p.6 of AZ 40XT-11D Photoresist technical datasheet (Rev. 7/2016)
- Muller et al.. Advanced fabrication process for particle absorbers of highly pure electroplated gold for microcalorimeter applications. Journal of Applied Physics (2024). doi:10.1063/5.0238524AZ 40XT was chosen as the upper layer of a double-resist stack for its 15-100 um thickness range, the authors noting that as a chemically amplified resist it gives steep edges at comparatively low dose and short development, and used again as a single layer for the second gold absorber half.
- Ceddia et al.. Universal mask for hard x rays. Optica (2023). doi:10.1364/OPTICA.490006AZ 40XT-11D was spin-coated and baked at 126 C for 5 min as the patterning layer for the absorber mask used in a hard x-ray ghost-projection demonstration.
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 2026-09-28.