https://nanyte.com/photoresists/su-8-50 · last updated 2026-10-15
- Manufacturer
- Kayaku Advanced Materials
- Tone
- negative
- Chemistry
- Epoxy (SU-8 type)
- Thickness
- 40–100 µm
- Developer
- SU-8 Developer (Kayaku); ethyl lactate or diacetone alcohol also usable
- Applications
- MEMS structural · High aspect ratio · Electroplating / molding
Cross-checked — the spin curve (where published) and the single-value figures were read twice, independently, from the datasheet, with any disagreement settled against it.
- Substrate
- Resist
- Exposed
Spin coating
Data points
| Series | rpm | µm | Published dose |
|---|---|---|---|
| SU-8 50 | 1000 | 100 | 325–550 mJ/cm² · 100 µm row within 10 % of a bracket edge |
| 2000 | 50 | 250–450 mJ/cm² · 50 µm row within 10 % of a bracket edge | |
| 3000 | 40 | 225–400 mJ/cm² · 40 µm row within 10 % of a bracket edge |
Values are the manufacturer’s starting points, not a guarantee — characterize on your own tool.
Published dose is the datasheet’s own thickness bracket, quoted as printed — the full table and its citation are in the exposure section. A thickness the table does not cover shows nothing, and a thickness within 10 % of a bracket edge shows every bracket it could fall in.
Table 1 'Approximate Thickness vs. Spin Speed Data for Selected SU-8 Resists', p.2 of the SU-8 50-100 Technical Data Sheet, Kayaku Advanced Materials, September 2020 - SU-8 50 rows: 40 µm at 3000 rpm, 50 µm at 2000 rpm, 100 µm at 1000 rpm (numeric table values, not read from a figure, transcribed exactly; the sheet calls these approximate). Figure 1 on the same page plots a continuous trace for SU-8 50 that sits above the table at the low speeds (about 115 µm at 1000 rpm and 57 µm at 2000 rpm by eye) and close to it at 3000 rpm; the table values are used.
- Dispense about 1 ml of resist per inch of substrate diameter.
- Spread at 500 rpm, ramped at 100 rpm/s and held 5-10 s so the resist covers the whole surface, then ramp at 300 rpm/s to the final speed and hold for a total of 30 s.
- The thickness table has only three speeds for this grade (1000, 2000 and 3000 rpm), and its plotted trace runs somewhat above the table at the low-speed end, so treat the thickness for any other speed as an estimate and confirm it on a test wafer.
- The process flow includes an edge-bead removal step between coat and soft bake but gives no parameters for it.
- Adhesion
- No adhesion promoter is named. The sheet asks for a clean, dry substrate: solvent clean or dilute-acid rinse followed by DI water, piranha etch/clean where applicable, then a 5 min dehydration bake at 200 °C on a hotplate. If the SU-8 will later be removed after electroplating, OmniCoat goes on the substrate before the SU-8.
Soft bake
- Soft bake
- 95 °C · hotplate
- Notes
- Two-step contact hotplate bake, 65 °C then 95 °C, with the time set by the film you coated: 40 µm 5 min + 15 min, 50 µm 6 min + 20 min, 100 µm 10 min + 30 min. Stepping or ramping the temperature is recommended because a gentler start gives better coating fidelity, a smaller edge bead and better adhesion. The times are for a level contact hotplate; the sheet says convection ovens may also be used, and that proximity and oven bakes need their own optimisation.
SOURCE: Table 2 'Recommended Soft Bake Parameters', p.3 of the SU-8 50-100 Technical Data Sheet, September 2020 (SU-8 50 rows)
Exposure dose
SU-8 50'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
- Dose follows the film you coat rather than the grade: roughly 225-400 mJ/cm² at 40 µm, 250-450 at 50 µm and 325-550 at 100 µm, read off the datasheet's upper and lower exposure limits.
- Post-exposure bake
- 95 °C
| Film thickness | Dose |
|---|---|
| 40 µm | 225–400 mJ/cm² |
| 50 µm | 250–450 mJ/cm² |
| 100 µm | 325–550 mJ/cm² |
SOURCE: SU-8 50-100 Technical Data Sheet
read from Figure 3 'Exposure Dose', p.3 of the SU-8 50-100 Technical Data Sheet, September 2020: two curves (upper and lower limit of the exposure range, mJ/cm2) against film thickness (0-250 µm, linear axes), evaluated at 40, 50 and 100 µm - the thicknesses in this grade's spin table - and rounded to the nearest 25 mJ/cm2. The sheet's text refers to this as 'Table 3', but the page carries a figure and no numeric table, so these are chart reads, good to roughly +/-25-50 mJ/cm2. Not attributed to a wavelength; the text says the recommendations rest on an i-line (365 nm) radiometer reading.
Development
- Developer
- SU-8 Developer (Kayaku); ethyl lactate or diacetone alcohol also usable
- Method
- immersion; spray or spray-puddle also usable
- Rinse
- Spray rinse with fresh developer, then dry with a gentle stream of filtered air or nitrogen. Strong agitation is recommended for high-aspect-ratio or thick structures.
- Developer family
- Solvent
Not published for this resist: Dilution, Time — characterize on-tool.
SOURCE: SU-8 50-100 Technical Data Sheet
Table 5 'Recommended Develop Processes' and the Develop and Rinse and Dry sections, p.4 of the SU-8 50-100 Technical Data Sheet, September 2020
Hard bake, etch & strip
- Hard bake
- 150–200 °C (optional — when the resist stays on the device)
- Descum
- Not published — characterize on-tool
- Etch resistance
- Described only in general terms, as chemically and thermally resistant once crosslinked; the sheet gives no etch rates or etchant compatibility list.
- Stripper
- Cured SU-8 is extremely hard to remove with conventional solvent strippers. Kayaku Remover PG at 50-80 °C for 30-90 min swells and lifts minimally crosslinked material; with OmniCoat underneath it should lift the SU-8 off cleanly. Fully cured or hard-baked SU-8 will not come off in Remover PG without OmniCoat. Other routes named: oxidizing acid solutions such as piranha, plasma ash (RIE at 200 W, 80 sccm O2, 8 sccm CF4, 100 mTorr, 10 °C), RIE, laser ablation and pyrolysis.
- Storage
- Store upright in tightly closed containers, cool and dry, out of direct sunlight, at 4-21 °C (40-70 °F), away from light, acids, heat and ignition sources. Shelf life is 13 months from the date of manufacture.
SOURCE: Processing Guidelines, p.2, and Hard Bake (cure) section, p.4 of the SU-8 50-100 Technical Data Sheet, September 2020
Where it's used
Practical notes from the datasheet
SU-8 50 is the thinner of the two grades on Kayaku's original SU-8 50-100 sheet; the sheet gives it a viscosity of 12,250 cSt against 51,500 cSt for SU-8 100. Everything on the page is thickness-indexed: soft bake, PEB, develop time and dose are each tabulated against film thickness rather than grade, so read the row that matches the coat you made. This is a different datasheet from the SU-8 2000 series (its own table numbering, its own bake and develop times), so figures from one should not be carried to the other. The film is formulated to be imaged, cured and left in place, and the removal route is hard once it is crosslinked; plan a sacrificial OmniCoat layer up front if the structure will need to be released.
Grades in this family
Other grades in the SU-8 (original series, formulations 50-100) line differ mainly in coating thickness:
| Grade | Thickness |
|---|---|
| SU-8 50 (this page) | 40–100 µm |
| SU-8 100 | 100–250 µm |
Troubleshooting
Common failure modes for SU-8 50, 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.
SU-8 50 is cracking or lifting off the substrate. What does the datasheet say to change?
It reads catastrophic adhesion failure and heavy cracking as under-crosslinking, and the fix is a higher exposure dose and/or a longer PEB. It also warns that SU-8 crosslinks readily and can end up highly stressed, so use a slow ramp or the two-step 65 °C then 95 °C PEB and avoid cooling the wafer quickly afterwards.
SOURCE: SU-8 50-100 Technical Data Sheet, September 2020 - Exposure section, p.3, and PEB tip, p.4
How long should SU-8 50 soft bake?
It depends on the coat: 5 min at 65 °C then 15 min at 95 °C for 40 µm, 6 + 20 min for 50 µm and 10 + 30 min for 100 µm, on a level contact hotplate. Stepping the temperature gives better coating fidelity and less edge bead than going straight to 95 °C. Oven and proximity bakes need their own optimisation.
SOURCE: SU-8 50-100 Technical Data Sheet, September 2020 - Table 2 and the Soft Bake section, pp.2-3
Sources & disclaimer
- Kayaku Advanced Materials — SU-8 50 datasheet (SU-8, 50-100, Technical Data Sheet, Kayaku Advanced Materials, September 2020 (printed in the page footers, 'Page n/5'). The downloaded file also contains the companion SU-8 2-25 sheet, September 2020 Ver. 1; only the 50-100 sheet is used here.) · accessed 2026-10-15
- https://microresist.de/produkt/su-8-series/ — distributor product page the datasheet was downloaded from
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 2026-10-15.