https://nanyte.com/photoresists/az-p4903 · last updated 2026-09-13
- Manufacturer
- Merck KGaA (AZ Electronic Materials)
- Tone
- positive
- Thickness
- 10–30 µm
- Developer
- AZ 400K at 1:4, or at 1:3 / AZ 421K (unbuffered) for films above 12 µm; AZ Developer 1:1 where aluminium must not be etched; AZ 340 is also listed
- Applications
- Electroplating / molding · Etch mask
- Substrate
- Resist
- Exposed
Spin coating
The manufacturer does not publish a spin curve for AZ P4903.
- No spin curve is published for this grade — the chart on p.2 covers only P4110, P4210, P4330 and P4400.
- Films this thick are not spun to equilibrium; the sheet gives an example coating sequence for films above 20 µm on p.5: low-speed spin at 500 rpm for 4 s, dispense at rest for 5 s, spread at 300 rpm for 3-5 s, a cast spin whose time and speed depend on the target thickness, then edge-bead removal at 400 rpm for 20 s and a 10 s dry at 400 rpm, with accelerations of 20-50 krpm/s.
- For the cast-spin settings the sheet refers you to the AZ representative.
- Adhesion
- HMDS recommended — 'Substrates must be clean, dry, and free of organic residues.
- Rehydration
- Required for films thicker than 4.0 µm: hold between soft bake and exposure for typically 30-60 minutes, depending on film thickness, at 40-45 % relative humidity (Film rehydration, p.6).
Soft bake
- Soft bake
- 95–115 °C
- Notes
- No time is published for this grade.
SOURCE: Soft bake section, p.6, and typical process box, p.1, of the AZ P4000 Series technical datasheet, Rev. (08/21)
Exposure dose
AZ P4903's dose is published against film thickness, not as a single number. Read the row for the film you coat and run a dose array around it.
- As published
- No dose is given for AZ P4903 by name.
| Film thickness | Dose |
|---|---|
| 1.5 µm | 90 mJ/cm² |
| 3.5 µm | 135 mJ/cm² |
| 12 µm | 800 mJ/cm² |
SOURCE: 'Approximate exposure dose requirement vs. film thickness…
'Approximate exposure dose requirement vs. film thickness (Suss MA-200)' table, p.5 of the AZ P4000 Series technical datasheet, Rev. (08/21): 1.5 µm 90 mJ/cm², 3.5 µm 135 mJ/cm², 12 µm 800 mJ/cm². The table is published for the P4000 series as a whole, indexed by film thickness rather than by grade.
Development
- Developer
- AZ 400K at 1:4, or at 1:3 / AZ 421K (unbuffered) for films above 12 µm; AZ Developer 1:1 where aluminium must not be etched; AZ 340 is also listed
- Dilution
- AZ 400K 1:4 for better selectivity on thinner films, 1:3 for films above 12 µm; AZ Developer 1:1
- Method
- spray or immersion
- Developer family
- Buffered alkaline
Not published for this resist: Time, Rinse — characterize on-tool.
SOURCE: Developing section, p.6, and companion products, p.1, of the AZ P4000 Series technical datasheet, Rev. (08/21)
Hard bake, etch & strip
- Hard bake
- 100–110 °C
- Etch resistance
- 'Excellent substrate adhesion for wet etch applications' (p.1); a 100-110 °C hard bake 'improves adhesion in wet etch or plating applications and improves pattern stability in dry etch processes' (p.6).
- Stripper
- AZ 300T, AZ 400T or AZ Kwik Strip (companion products, p.1).
Not published for this resist: Descum, Storage — characterize on-tool.
SOURCE: Hard bake section, p.6, and dielectric insulator table, p.5, of the AZ P4000 Series technical datasheet, Rev. (08/21)
Where it's used
Practical notes from the datasheet
AZ P4903 is the most viscous P4000 grade (1650 cSt at 23 °C, three times AZ P4620) and the one for the tallest single-coat plating moulds, rated from 10 µm to beyond 30 µm. The sheet is candid that this range is reached with special coating programs rather than a spin curve, and it publishes the skeleton of one: a slow spread, a thickness-specific cast spin, and edge-bead removal at 400 rpm. Everything about processing gets slower at this thickness. Soft bake may need a ramped temperature to stop solvent outgassing from raising bubbles, the 30-60 minute rehydration hold at 40-45 % RH scales with film thickness, and the dose climbs steeply — the series table already reads 800 mJ/cm² at 12 µm on a Suss MA-200. Develop in AZ 400K 1:3 or AZ 421K, which the sheet recommends above 12 µm.
Grades in this family
Other grades in the AZ P4000 Series line differ mainly in coating thickness:
| Grade | Thickness |
|---|---|
| AZ P4110 | 1–3 µm |
| AZ P4210 | 2–4 µm |
| AZ P4330-RS | 3–5 µm |
| AZ P4400 | 4–6 µm |
| AZ P4620 | 6.9–14.8 µm |
| AZ P4903 (this page) | 10–30 µm |
Sources & disclaimer
- Merck KGaA (AZ Electronic Materials) — AZ P4903 datasheet (Rev. (08/21)) · 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 2026-09-13.