SU-8 2100 process recipe

SU-8 2100 is the very-thick-film grade of the SU-8 2000 family — the choice when a single coat must reach into the hundreds of microns, well beyond what SU-8 2025 or 2050 can lay down, at the cost of hour-scale bakes. SU-8 2100 is a very high-viscosity member of MicroChem's SU-8 2000 epoxy negative photoresist series, coating roughly 100-270 µm in a single pass for thick, permanent, high-aspect-ratio microstructures.

https://nanyte.com/photoresists/su-8-2100 · last updated 2026-07-12

At a glance

Manufacturer: MicroChem
Tone: negative
Chemistry: Epoxy (SU-8 type)
Thickness: 103–269 µm
Developer: SU-8 Developer (MicroChem)
Applications: High aspect ratio · MEMS structural · Electroplating / molding

Cross-checked — two independent extractions agree.

Coat103–269 µm

—01 / Coating

Spin coating

SU-8 2100 is spin-coated to 103–269 µm. The curve below is redrawn from the manufacturer's published data — read your target thickness off the vertical axis and take the matching spin speed as a starting point.

Data points

SU-8 2100 — film thickness (µm) by spin speed (rpm)
Series	rpm	µm
SU-8 2100	1000	269
	2000	137
	3000	103

Values are the manufacturer's starting points, not a guarantee; verify on your own tool. Characterize on-tool. Series digitized from a published figure were independently cross-checked by a second blind read; treat those values as approximate (±10 %).

re-extracted 2026-07-12, pixel-calibrated (PyMuPDF: axis-tick word coordinates for calibration, vector marker path rects for data points, colored (0,0,1)=blue to isolate from the red 2150 trace); Figure 1 "SU-8 2000 Spin Speed versus Thickness", p.2 of MicroChem "SU-8 2000 Permanent Epoxy Negative Photoresist Processing Guidelines for SU-8 2100 and SU-8 2150" (CNR-Nano mirror). Chart plots only two curves, unambiguously distinguished by both color and marker shape: SU-8 2150 = red triangles (top curve), SU-8 2100 = blue circles (bottom curve), matching Table 1's viscosity ordering (2100 = 45,000 cSt < 2150 = 80,000 cSt, so 2100 should coat thinner at a given speed). Each curve has only 3 markers, at 1000/2000/3000 rpm — the blue trace does not extend to 3500 rpm despite the chart's wider axis range. Supersedes the earlier eyeball read (270/137/105), which was already close but imprecise.

Redrawn from the manufacturer's published data — hover to read values between points, click to pin.

Recommended program (same for both grades in this document): dispense 1 ml of resist per inch (25 mm) of substrate diameter; spin at 500 rpm for 5-10 s at 100 rpm/s acceleration, then spin at the target speed (per Figure 1) for 30 s at 300 rpm/s acceleration. Edge bead removal (EBR) with MicroChem's EBR PG solvent stream at the wafer edge is recommended before soft bake, both to limit hotplate contamination and to let the photomask reach close contact with the wafer. Source: "Coat" / "Recommended Program" / "Edge Bead Removal (EBR)", p.2.

Adhesion: HMDS not required — "Adhesion promoters are typically not required." HMDS pretreatment (MCC Primer 80/20) is recommended only "for applications that include electroplating." Source: "Substrate Preparation", p.2.

—02 / Bake

Soft bake

Soft bake: Not published — characterize on-tool
Notes: Published only as a THICKNESS-BINNED table shared by both grades covered in this document (SU-8 2100 and 2150), not a single value per grade: 100-150 µm → 5 min @65°C then 20-30 min @95°C; 160-225 µm → 5-7 min @65°C then 30-45 min @95°C; 230-270 µm → 7 min @65°C then 45-60 min @95°C; 280-550 µm → 7-10 min @65°C then 60-120 min @95°C. SU-8 2100's own spin curve spans roughly 105-270 µm (1000-3000 rpm), i.e. mostly the 100-150 and 230-270 µm bins. Convection ovens are explicitly not recommended (can skin over and trap solvent). A cool-down/re-heat 'wrinkle' check is described to confirm the film is fully dry.

SOURCE: Table 2 "Soft Bake Times", p.2 of the MicroChem SU-8 2000 (2100-2150) Processing Guidelines

—03 / Exposure

Exposure dose

The manufacturer does not publish a clearing dose for SU-8 2100. Determine it with a dose array on your own tool.

As published: "SU-8 2000 photoresist is most commonly exposed with conventional UV (350-400 nm) radiation, although i-line (365 nm) is the recommended wavelength. SU-8 2000 may also be exposed with e-beam or x-ray radiation." (Processing Guidelines, p.1). The dose table itself (Table 3) is not separately re-attributed to a specific wavelength beyond this general statement.

—04 / Development

Development

Developer: SU-8 Developer (MicroChem)
Method: immersion
Rinse: IPA
Developer family: Solvent

SOURCE: "Development" and "Rinse and Dry" sections plus Table 6 "Development Times for SU-8 Developer", p.3

—05 / Post-processing

Hard bake, etch & strip

Stripper: MicroChem Remover PG swells and lifts only minimally cross-linked SU-8 2000. A fully cured/hard-baked film cannot be removed with Remover PG alone — it requires an OmniCoat (30-100 nm) sacrificial underlayer (heat Remover PG to 50-80°C, immerse 30-90 min) or an oxidizing strip (piranha etch, plasma ash, RIE, laser ablation, or pyrolysis). RIE recipe given: 200 W, 80 sccm O2, 8 sccm CF4, 100 mTorr, 10°C. Source: "Removal" / "Plasma Removal", p.4.
Storage: Store upright in tightly closed containers, cool and dry, away from direct sunlight, at 40-70°F (4-21°C); away from light, acids, heat, and ignition sources. Shelf life is thirteen months from date of manufacture (note: the sibling 2025-2075 processing document states twelve months — the two documents disagree on shelf life). Source: "Storage", p.4.

SOURCE: "Hard Bake (cure)" section, p.4

—06 / Applications

Where it's used

High aspect ratioMEMS structuralElectroplating / molding

SU-8 2100 is the second-highest-viscosity grade in MicroChem's SU-8 2000 line (45,000 cSt) and is built for very thick, single-coat films — its own spin curve runs roughly 105-270 µm over 1000-3000 rpm. Reach for 2100 only when the device genuinely needs that film height; its long soft-bake and develop times and thick-film handling make the thinner SU-8 2025 and 2050 grades the better default whenever they can meet the thickness target. Like every SU-8 2000 grade, it cross-links in two stages — exposure generates acid, and the post-exposure bake thermally drives the epoxy cross-linking — so PEB is a required processing step, not an optional cure, and at this thickness the bake times stretch into hours (up to 60-120 minutes soft bake and 20-30 minutes PEB at 95°C for the thickest bin in this document). Soft-bake, PEB, dose and develop times are published only as thickness-binned ranges shared with SU-8 2150; treat the low end of the matching bin as a starting point and use the datasheet's cool-down/re-heat 'wrinkle' test to confirm the soft bake is complete before proceeding. Once fully cross-linked, SU-8 is notoriously hard to strip: plain solvent remover only works on minimally exposed/baked film, and a hard-baked structure needs either a sacrificial OmniCoat layer beneath it or an oxidizing strip (piranha, plasma ash, RIE, laser ablation, pyrolysis) to remove. Edge bead removal before soft bake is especially important at this film thickness to keep the photomask in close contact with the wafer.

—07 / Sources

Sources & disclaimer

MicroChem — SU-8 2100 datasheet (No revision/date string is printed in the document body (a 5-page processing-guidelines PDF with no header/footer revision code). The mirror's filename indicates 'Ver5' (a byu.edu mirror of the apparently same document is filenamed 'Ver5-1').) · accessed 2026-07-10

Research using this resist

Shaw et al.. Negative photoresists for optical lithography. IBM Journal of Research and Development (1997). doi:10.1147/rd.411.0081
The IBM origin paper of SU-8.
Lorenz et al.. SU-8: a low-cost negative resist for MEMS. Journal of Micromechanics and Microengineering (1997). doi:10.1088/0960-1317/7/3/010
15:1 aspect ratios in 1997 — the paper that made SU-8 a MEMS resist.
del Campo et al.. 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/R01
The canonical SU-8 review.
Qasaimeh et al.. Microfluidic probes for use in life sciences and medicine. Lab Chip (2013). doi:10.1039/C2LC40898H
Free-standing SU-8 microfluidic probes for live-cell chemistry.

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 2026-07-12.

Cite this recipe

NANYTE. "SU-8 2100 process recipe." NANYTE Photoresist Library. https://nanyte.com/photoresists/su-8-2100. Accessed 2026-07-12.

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