https://nanyte.com/photoresists/su-8-2050 · last updated 2026-07-26
- Manufacturer
- Kayaku Advanced Materials
- Tone
- negative
- Chemistry
- Epoxy (SU-8 type)
- Thickness
- 40.1–171 µm
- Developer
- SU-8 Developer (Kayaku's proprietary PGMEA-based developer); other solvent developers such as ethyl lactate or diacetone alcohol are also stated to work
- Applications
- MEMS structural · High aspect ratio · Microfluidics · Electroplating / molding
- Substrate
- Resist
- Exposed
Spin coating
Data points
| Series | rpm | µm | Published dose |
|---|---|---|---|
| SU-8 2050 | 1000 | 171 | 260–350 mJ/cm² · 160–225 µm row within 10 % of a bracket edge |
| 2000 | 76 | 150–215 mJ/cm² · 45–80 µm row within 10 % of a bracket edge | |
| 3000 | 53 | 150–215 mJ/cm² · 45–80 µm row | |
| 4000 | 40 | — |
Values are the manufacturer’s starting points, not a guarantee — characterize on your own tool. Series digitized from a published figure are approximate (±10 %).
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.
read from Figure 1 'SU-8 2000 Thickness vs. Spin Speed', p.2 of SU-8 2000 (2025-2100) Technical Data Sheet, Kayaku Advanced Materials, April 2021 — the chart plots four family curves (2025/2035/2050/2075) together with axis gridlines every 20 µm (0-240) and every 500 rpm (500-4500); no numeric table is published for this figure. The chart is drawn as vector paths rather than a raster image, so the marker positions read exactly. It plots exactly FOUR markers per series, at 1000/2000/3000/4000 rpm only. SU-8 2050 is the second-from-top series (triangle marker) by y-order at each rpm column, consistent with its rank between SU-8 2075 (top) and SU-8 2035 (third).
- Kayaku's stated 'Recommended Program' (family-wide, not thickness-specific): dispense 1 ml resist per inch (25 mm) of substrate diameter
- spin at 500 rpm for 5-10 s at 100 rpm/s acceleration (spread step)
- then spin at 2000 rpm for 30 s at 300 rpm/s acceleration as a generic starting point — the actual final rpm/time should be taken from Figure 1 for the desired thickness.
- Edge-bead removal (EBR) with a solvent stream (Kayaku EBR PG) at the wafer edge is recommended so the mask can seat in close contact.
- Secondary/practical (Cornell Nanoscale Facility SOP, university source, not the vendor): pour SU-8 2050-or-thicker from stock into small working bottles at least 24 h before spinning to let entrained bubbles dissipate
- for layers ≥150 µm, let the wafer rest on the spinner after spin-up so hanging edge resist can retract back onto the wafer before wiping the edge bead, since a fully removed edge bead will just reflow into the gap during softbake.
- Adhesion
- HMDS not required — Adhesion promoters are stated as 'typically not required' for standard use.
Soft bake
- Soft bake
- 95 °C · hotplate
- Notes
- Datasheet times are given per THICKNESS bracket, not per grade, so bake to the bracket matching the film actually coated.
SOURCE: Table 2 'Soft Bake Times', p.3 of SU-8 2000 (2025-2100) Technical Data Sheet, Kayaku Advanced Materials, April 2021
Exposure dose
SU-8 2050'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
- SU-8 2050's typical 45–80 µm coats take 150–215 mJ/cm²; the dose is indexed to the film you spun, so a 100 µm coat needs 215–240 mJ/cm² instead.
- Post-exposure bake
- 95 °C
| Film thickness | Dose |
|---|---|
| 25–40 µm | 150–160 mJ/cm² |
| 45–80 µm | 150–215 mJ/cm² |
| 85–110 µm | 215–240 mJ/cm² |
| 115–150 µm | 240–260 mJ/cm² |
| 160–225 µm | 260–350 mJ/cm² |
| 230–270 µm | 350–370 mJ/cm² |
SOURCE: SU-8 2000 (2025-2100) Technical Data Sheet
Table 3 'Exposure Dose' of the SU-8 2000 (2025-2100) Technical Data Sheet, Kayaku Advanced Materials, April 2021 — indexed by film thickness and shared across the grades that document covers. Not explicitly attributed to a wavelength.
Development
- Developer
- SU-8 Developer (Kayaku's proprietary PGMEA-based developer); other solvent developers such as ethyl lactate or diacetone alcohol are also stated to work
- Dilution
- undiluted
- Time
- Not published — characterize on-tool
- Method
- immersion (spray or spray-puddle also usable per datasheet)
- Rinse
- Fresh SU-8 developer spray/wash ~10 s, optionally repeated, then air/N2 dry with filtered pressurized gas.
- Developer family
- Solvent
SOURCE: SU-8 2000 (2025-2100) Technical Data Sheet
Table 6 'Development Times for SU-8 Developer' (45-75 µm bracket: 5-7 min), p.4 of SU-8 2000 (2025-2100) Technical Data Sheet, Kayaku Advanced Materials, April 2021
Hard bake, etch & strip
- Hard bake
- 150–250 °C · 5–30 min
- Descum
- Not published — characterize on-tool
- Etch resistance
- Described as chemically and thermally very stable once crosslinked: thermal stability to 315°C (5% wt. loss), and the Removal section states it is 'extremely difficult to remove... with conventional solvent based resist strippers.' This robustness makes cured SU-8 usable as a durable etch/plating mold in many wet-chemical processes, at the cost of being hard to strip afterward (see stripper field).
- Stripper
- Minimally-crosslinked SU-8: Kayaku Remover PG, 50-80°C bath, 30-90 min immersion (swells and lifts off partially-cured material; if OmniCoat 30-100 nm sacrificial layer was applied first, Remover PG gives a clean full lift-off).
- Storage
- Store upright in tightly closed containers, in a cool dry environment away from direct sunlight, light, acids, heat, and ignition sources, at 40-70°F (4-21°C).
SOURCE: Hard Bake (cure) section, p.5 of SU-8 2000 (2025-2100) Technical Data Sheet, Kayaku Advanced Materials, April 2021
Where it's used
Practical notes from the datasheet
SU-8 2050 sits in the middle of the SU-8 2000 family by viscosity (12,900 cSt vs. 4,500 for 2025 and 22,000 for 2075) and covers roughly 45-165 µm in a single coat over the datasheet's plotted 1000-4000 rpm range (the family description states thicknesses down to 0.5 µm and beyond 200 µm are achievable across the whole SU-8 2000 line, implying lower speeds than plotted would push a single 2050 coat higher still, but that isn't shown numerically for this grade). Choose 2050 over the thinner SU-8 2025 when a structure needs more height and mechanical robustness, and over the much thicker SU-8 2100/2150 grades when their hour-long bakes and very deep develops would otherwise dominate the process. PEB is the step where crosslinking actually completes (thermally-driven, acid-catalyzed epoxy reaction) -- a visible latent mask image appearing within 5-15 s of starting the 95°C PEB is the datasheet's own go/no-go check for adequate exposure and heating. Thick films are prone to cracking and delamination from thermal stress; besides the softbake wrinkle-check cycle, a University of Cornell Nanoscale Facility SOP (secondary source, not the vendor) recommends gradual heating/cooling for any layer >=50 µm, since silicon cools faster than SU-8, and a ~10 minute wait between exposure and PEB start for full latent-image (photoacid) formation. Because fully cross-linked SU-8 is essentially unstrippable with ordinary solvents, any process that will need to remove or release the structure later should plan for an OmniCoat sacrificial layer from the start, not as an afterthought.
Grades in this family
Other grades in the SU-8 2000 series line differ mainly in coating thickness:
Troubleshooting
Common failure modes for SU-8 2050, 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.
What soft bake time and temperature does SU-8 2050 need?
Soft-bake times are given per film-thickness bracket, not per grade. For a typical SU-8 2050 film in the 45–80 µm range (about 3000 rpm), the datasheet specifies 0–3 min at 65°C followed by 6–9 min at 95°C on a level hotplate. Convection ovens are not recommended — a skin can form and trap solvent. After baking, cool the wafer to room temperature and reheat; if the film wrinkles, continue baking a few minutes and repeat until wrinkles no longer appear.
SOURCE: Kayaku SU-8 2000 (2025–2100) Technical Data Sheet, April 2021 — Table 2 Soft Bake Times, p.3
What is the exposure dose for SU-8 2050?
Dose is published by film thickness, not by grade. SU-8 2050's typical ~45–80 µm working range falls in the 150–215 mJ/cm² bracket. i-line (365 nm) is the recommended wavelength (conventional UV 350–400 nm is also used). Multiply by ~1.5× on glass/Pyrex/ITO and 1.5–2× on silicon nitride and most metals versus silicon. A 350 nm long-pass filter for vertical sidewalls needs ~40% more exposure. No separate 405 nm dose is published.
SOURCE: Kayaku SU-8 2000 (2025–2100) Technical Data Sheet, April 2021 — Table 3 Exposure Dose + Table 4 substrate multipliers
Does SU-8 2050 need a post-exposure bake?
Yes — PEB is where cross-linking actually completes (a thermally driven, acid-catalyzed epoxy reaction), so it is essential. Times are thickness-binned; for the 45–80 µm bracket, an optional 1–2 min at 65°C for stress reduction then 6–7 min at 95°C, starting directly after exposure. A latent mask image should appear within 5–15 s of reaching 95°C; if none forms, exposure or heating was inadequate.
SOURCE: Kayaku SU-8 2000 (2025–2100) Technical Data Sheet, April 2021 — Table 5 Post Exposure Bake Times, p.4
Which developer does SU-8 2050 use?
SU-8 Developer, Kayaku's PGMEA-based developer, used undiluted by immersion (spray or spray-puddle also work); ethyl lactate and diacetone alcohol are also stated to work. For the 45–75 µm bracket, immersion runs about 5–7 min. A white film during rinse means the unexposed resist is under-developed — apply more SU-8 developer rather than relying on IPA. Ultrasonic or megasonic agitation is recommended for high-aspect-ratio or tight-pitch structures.
SOURCE: Kayaku SU-8 2000 (2025–2100) Technical Data Sheet, April 2021 — Table 6 Development Times, p.4
Why is my SU-8 2050 cracking or delaminating?
Thick SU-8 films are prone to cracking and delamination from thermal stress. The datasheet's soft-bake wrinkle test (cool then reheat, bake longer if it wrinkles) confirms the film is fully dry, and a short 150°C bake for a couple of minutes anneals cracks seen after development. For layers ≥50 µm a Cornell Nanoscale Facility SOP additionally recommends gradual heating and cooling, since silicon cools faster than SU-8.
SOURCE: Kayaku SU-8 2000 TDS Hard Bake section + Cornell Nanoscale…
Kayaku SU-8 2000 TDS Hard Bake section + Cornell Nanoscale Facility 'SU-8 Processing Suggestions' (v2, 2013), thermal-stress guidance
Sources & disclaimer
- Kayaku Advanced Materials — SU-8 2050 datasheet (SU-8 2000, 2025-2100, Technical Data Sheet, April 2021 (per footer on every page; fetched via a university-hosted mirror of the same document, https://nanofab.sites.olt.ubc.ca/files/2026/01/KAM-SU-8-2000-2025-2100-Datasheet-4.9.21-final-2.pdf, since kayakuam.com returned HTTP 403 to automated fetches during this session)) · accessed 2026-07-10
- https://www.cnfusers.cornell.edu/sites/default/files/Equipment-Resources/SU8%20processing%20suggestions.pdf — Cornell Nanoscale Facility 'SU-8 Processing Suggestions' (v2, July 2013) -- used only for practical process tips not in the vendor datasheet: pre-spin bubble-dissipation wait time for SU-8 2050+, the ~10 min exposure-to-PEB delay for latent image formation, and thermal-stress/cracking guidance for thick and multi-layer coats. Not used for any headline numeric spec (spin curve, dose, bake time/temp all come from the Kayaku datasheet).
- Shaw et al.. Negative photoresists for optical lithography. IBM Journal of Research and Development (1997). doi:10.1147/rd.411.0081The IBM origin paper for the EPON-based epoxy negative resist that became SU-8, describing its formulation and use as a thick optical-lithography resist.
- Lorenz et al.. SU-8: a low-cost negative resist for MEMS. Journal of Micromechanics and Microengineering (1997). doi:10.1088/0960-1317/7/3/010Established SU-8 as a MEMS structural resist, producing thick high-aspect-ratio structures by near-UV lithography.
- del Campo, Greiner. SU-8: a photoresist for high-aspect-ratio and 3D submicron lithography. Journal of Micromechanics and Microengineering (2007). doi:10.1088/0960-1317/17/6/R01Widely cited review of SU-8 processing (coat, bake, expose, develop) for high-aspect-ratio and 3D microstructures across the SU-8 family.
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.