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SU-8 100 process recipe

SU-8 100 (51,500 cSt) is the thick-coat grade of Kayaku's original SU-8 line: 100 µm at 3000 rpm, 150 µm at 2000 and 250 µm at 1000 rpm. Planning around it means long hotplate steps: the 250 µm coat soft bakes 30 min at 65 °C plus 90 min at 95 °C and then develops for 20 min. Its datasheet is the original-series sheet, not an SU-8 2000 one, so take bake, dose and develop figures from here.

https://nanyte.com/photoresists/su-8-100 · last updated 2026-10-15

At a glance
Download PDF
Manufacturer
Kayaku Advanced Materials
Tone
negative
Chemistry
Epoxy (SU-8 type)
Thickness
100–250 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.

The exposed resist stays after development; the unexposed film dissolves. Schematic cross-sections for SU-8 100 — feature width, film aspect ratio and sidewall angle are illustrative, not to scale.
—01 / Coating

Spin coating

Spin curve for SU-8 100: film thickness in µm against spin speed in rpm.501001502002503001k1.5k2k2.5k3kSPIN SPEED (rpm)THICKNESS (µm)
Data points
SU-8 100 — film thickness (µm) by spin speed (rpm)
SeriesrpmµmPublished dose
SU-8 1001000250
400–675 mJ/cm² · 250 µm row
within 10 % of a bracket edge
2000150
375–625 mJ/cm² · 150 µm row
within 10 % of a bracket edge
3000100
325–550 mJ/cm² · 100 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-8 100 rows: 100 µm at 3000 rpm, 150 µm at 2000 rpm, 250 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 SU-8 100 trace that runs about 5-15 % below the table (about 235 µm at 1000 rpm, 133 µm at 2000 rpm and 95 µm at 3000 rpm by eye); the table values are used.

Redrawn from the manufacturer's published data — hover to read between points, click to pin.
  • 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 lists three speeds only (1000, 2000 and 3000 rpm) and its plotted trace sits a little below the table, so treat any other speed's thickness 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.
—02 / Bake

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: 100 µm 10 min + 30 min, 150 µm 20 min + 50 min, 250 µm 30 min + 90 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-8 100 rows)

—03 / Exposure

Exposure dose

SU-8 100'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 325-550 mJ/cm² at 100 µm, 375-625 at 150 µm and 400-675 at 250 µm, read off the datasheet's upper and lower exposure limits.
Post-exposure bake
95 °C
SU-8 100 — dose by film thickness
Film thicknessDose
100 µm325–550 mJ/cm²
150 µm375–625 mJ/cm²
250 µm400–675 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 100, 150 and 250 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. The curves flatten above about 150 µm. Not attributed to a wavelength; the text says the recommendations rest on an i-line (365 nm) radiometer reading.

—04 / Development

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

—05 / Post-processing

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

—06 / Applications

Where it's used

Practical notes from the datasheet

SU-8 100 is the thicker of the two grades on Kayaku's original SU-8 50-100 sheet, at 51,500 cSt against 12,250 cSt for SU-8 50, and the only one whose table reaches 250 µm in a single coat. Soft bake, PEB, develop time and dose are each tabulated against film thickness rather than grade, so read the row for the coat you actually made; at this thickness the 95 °C steps (up to 90 min soft bake, 20 min develop) dominate cycle time. This is a different datasheet from the SU-8 2000 series, with its own table numbering and its own bake and develop times, so figures from one should not be carried to the other. Cured SU-8 is hard to strip, so plan a sacrificial OmniCoat layer up front if the structure must be released.

—07 / Family

Grades in this family

Other grades in the SU-8 (original series, formulations 50-100) line differ mainly in coating thickness:

SU-8 (original series, formulations 50-100) — grade comparison
GradeThickness
SU-8 5040–100 µm
SU-8 100 (this page)100–250 µm
—08 / Troubleshooting

Troubleshooting

Common failure modes for SU-8 100, 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.

A thick SU-8 100 coat cracks or delaminates after the PEB. 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 does SU-8 100 take to bake and develop at 250 µm?

The 250 µm row asks for a soft bake of 30 min at 65 °C then 90 min at 95 °C on a level contact hotplate, and an immersion develop of about 20 min with strong agitation. The sheet's PEB table lists 200 µm as its last row, so no PEB time is printed for 250 µm.

SOURCE: SU-8 50-100 Technical Data Sheet, September 2020 - Tables 2, 4 and 5, pp.3-4

—09 / Sources

Sources & disclaimer

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.

Cite this recipe

NANYTE. "SU-8 100 process recipe." NANYTE Photoresist Library. https://nanyte.com/photoresists/su-8-100. Accessed 2026-10-15.

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