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SU-8 3005 process recipe

SU-8 3005 is the thin end of the SU-8 3000 line: 65 cSt and 50 % solids, so a single coat lands at roughly 4.5–10 µm anywhere from 1000 to 4000 rpm. It is the grade for a thin permanent epoxy layer that stays on the device; the other four SU-8 3000 resists all start well above that thickness.

https://nanyte.com/photoresists/su-8-3005 · last updated 2026-10-15

At a glance
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Manufacturer
Kayaku MicroChem / MicroChem Corp.
Tone
negative
Chemistry
Epoxy (SU-8 type)
Thickness
4.5–9.8 µm
Developer
Kayaku Advanced Materials SU-8 developer (solvent based); ethyl lactate and diacetone alcohol are also named as 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 3005 — feature width, film aspect ratio and sidewall angle are illustrative, not to scale.
—01 / Coating

Spin coating

Spin curves for SU-8 3005: film thickness in µm against spin speed in rpm.46810121k2k3k4kSPIN SPEED (rpm)THICKNESS (µm)
Data points
SU-8 3005 — film thickness (µm) by spin speed (rpm)
SeriesrpmµmPublished dose
SU-8 3005 (21 °C, US & EU)10009.8
100–200 mJ/cm² · 8–10 µm rows (2)
125–200 mJ/cm² · 8–15 µm row
within 10 % of a bracket edge
20006.7
100–200 mJ/cm² · 4–10 µm row
30005.3
100–200 mJ/cm² · 4–10 µm row
40004.5
100–200 mJ/cm² · 4–10 µm row
SU-8 3005 (23 °C, Japan & Asia)10009.0
100–200 mJ/cm² · 8–10 µm rows (2)
20007.3
100–200 mJ/cm² · 4–10 µm row
30006.0
100–200 mJ/cm² · 4–10 µm row
40005.6
100–200 mJ/cm² · 4–10 µm row

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.

SU-8 3005 (21 °C, US & EU): read from figure: Figure 1, "SU-8 3000 Thickness vs. Spin Speed (21°C US & EU)", p.2 of the Kayaku Advanced Materials "SU-8 3000 Permanent Negative Epoxy Photoresist" technical data sheet (July 2020, Ver. 1). The SU-8 3005 trace is identified by its legend marker; the chart plots five grades (3050, 3035, 3025, 3010, 3005) on a linear spin-speed axis (0–5000 rpm) and a linear film-thickness axis. The chart is a bitmap, so each point was located against the 0 and full-scale gridlines of both axes: one marker per 1000 rpm from 1000 to 4000 rpm, which is the trace's full plotted range, nothing beyond it. Values are good to roughly ±1 µm, and no numeric table accompanies the chart.

SU-8 3005 (23 °C, Japan & Asia): read from figure: Figure 2, "SU-8 3000 Thickness vs. Spin Speed (23°C Japan & Asia)", p.2 of the Kayaku Advanced Materials "SU-8 3000 Permanent Negative Epoxy Photoresist" technical data sheet (July 2020, Ver. 1). The SU-8 3005 trace is identified by its legend marker; the chart plots five grades (3050, 3035, 3025, 3010, 3005) on a linear spin-speed axis (0–5000 rpm) and a linear film-thickness axis. The chart is a bitmap, so each point was located against the 0 and full-scale gridlines of both axes: one marker per 1000 rpm from 1000 to 4000 rpm, which is the trace's full plotted range, nothing beyond it. Values are good to roughly ±1 µm, and no numeric table accompanies the chart.

2 series redrawn from the manufacturer's published data — hover to read between points, click to pin.
  • Program printed for the whole SU-8 3000 line: dispense 1 ml of resist per inch (25 mm) of substrate diameter, spread at 500 rpm for 5–10 s (100 rpm/s acceleration), then spin at 3000 rpm for 30 s (300 rpm/s acceleration).
  • Pick the final speed from the chart that matches your material and room: Figure 1 is for 21 °C (US and EU), Figure 2 for 23 °C (Japan and Asia), and the two give different thicknesses for the same grade and speed.
  • SU-8 3005 is 65 cSt, 50 % solids, density 1.075 g/ml (Table 1, p.2).
  • At 65 cSt this is by far the runniest grade in the table, and its trace on both charts is shallow: spin speed moves the film by only about 3–5 µm across 1000–4000 rpm, so thickness is set mainly by choosing the grade, not the speed.
  • The sheet advises removing the edge bead with a small stream of EBR PG solvent at the wafer edge, from above or below, so the hotplate stays clean and the mask can sit in closer contact.
  • Both thickness charts end at 4000 rpm and carry markers only at 1000, 2000, 3000 and 4000 rpm.
  • Beyond those points the datasheet gives no thickness data for this grade.
Adhesion
HMDS not required — Adhesion promoters are typically not needed on a substrate cleaned with a piranha etch (H2SO4 and H2O2, then a deionised-water rinse) or with RIE or an O2 barrel asher. For electroplating work the sheet recommends an HMDS pre-treatment of the substrate. (Substrate Preparation, p.2)
—02 / Bake

Soft bake

Soft bake
95 °C · hotplate
Notes
Temperature is 95 °C for every thickness; only the time changes with film thickness (Table 2). Rows that apply to SU-8 3005: 4–10 µm → 2–3 min; 8–15 µm → 5–10 min. No single time is quoted because the film thickness decides the row. Use a level hotplate; convection ovens are not recommended because a skin can form and trap solvent. To check the bake, cool the wafer to room temperature and put it back on the plate: if the film wrinkles, bake a few minutes longer and repeat until it stays smooth.
SOURCE: Table 2 "Soft Bake Times" and Soft Bake section, p.3 of the…

Table 2 "Soft Bake Times" and Soft Bake section, p.3 of the Kayaku Advanced Materials "SU-8 3000 Permanent Negative Epoxy Photoresist" technical data sheet (July 2020, Ver. 1)

—03 / Exposure

Exposure dose

SU-8 3005'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 film thickness, not the grade: 100–200 mJ/cm² for 4–10 µm and 125–200 mJ/cm² for 8–15 µm. SU-8 3005 coats about 4.5–10 µm, so it sits in the first row and just reaches into the second.
Post-exposure bake
95 °C
SU-8 3005 — dose by film thickness
Film thicknessDose
4–10 µm100–200 mJ/cm²
8–15 µm125–200 mJ/cm²
SOURCE: Table 3 "Exposure Dose", p.3 of the Kayaku Advanced Materials…

Table 3 "Exposure Dose", p.3 of the Kayaku Advanced Materials "SU-8 3000 Permanent Negative Epoxy Photoresist" technical data sheet (July 2020, Ver. 1). The table is indexed by film thickness and applies to the whole SU-8 3000 line; only the rows that overlap SU-8 3005's plotted thickness are listed here, as printed. The table is not tied to a single wavelength: the sheet recommends i-line (365 nm) and says conventional i-line plus broadband UV (350–400 nm) is the common practice.

—04 / Development

Development

Developer
Kayaku Advanced Materials SU-8 developer (solvent based); ethyl lactate and diacetone alcohol are also named as usable
Rinse
Spray or wash the developed image with fresh developer for about 10 s, then a second 10 s spray with developer if needed, and dry with filtered, pressurised air or nitrogen. The sheet recommends strong agitation for thick or high-aspect-ratio structures, and an ultrasonic or megasonic bath to clear vias and holes.
Developer family
Solvent

Not published for this resist: Dilution, Time, Method — characterize on-tool.

SOURCE: Develop and Rinse and Dry sections, p.4 of the Kayaku Advanced…

Develop and Rinse and Dry sections, p.4 of the Kayaku Advanced Materials "SU-8 3000 Permanent Negative Epoxy Photoresist" technical data sheet (July 2020, Ver. 1)

—05 / Post-processing

Hard bake, etch & strip

Hard bake
150–200 °C (optional — when the imaged resist stays on the finished device)
Descum
Not published — characterize on-tool
Etch resistance
Listed among the features as excellent dry etch resistance (p.1); no selectivity figure is given. The sheet's plasma removal recipe (RIE at 200 W, 80 sccm O2, 8 sccm CF4, 100 mTorr, 10 °C, p.5) is aimed at stripping cross-linked film.
Stripper
Kayaku Remover PG at 50–80 °C, 30–90 min immersion, swells and lifts minimally cross-linked SU-8 3000, and gives a clean lift-off of fully cross-linked film only if a 30–100 nm OmniCoat layer was put down first; it does not strip fully cured or hard-baked film without OmniCoat. To rework fully cross-linked film, the sheet names oxidising acid (piranha), plasma ash, RIE (200 W, 80 sccm O2, 8 sccm CF4, 100 mTorr, 10 °C), 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), and away from light, acids, heat and ignition sources. Shelf life is thirteen months from the date of manufacture.
SOURCE: Hard Bake (cure) section, p.5 of the Kayaku Advanced Materials…

Hard Bake (cure) section, p.5 of the Kayaku Advanced Materials "SU-8 3000 Permanent Negative Epoxy Photoresist" technical data sheet (July 2020, Ver. 1)

—06 / Applications

Where it's used

Practical notes from the datasheet

SU-8 3005: 65 cSt, 50 % solids, 1.075 g/ml (Table 1). The datasheet is written for the whole SU-8 3000 line, a high-contrast epoxy resist reformulated from SU-8 and SU-8 2000 for better adhesion and lower coating stress, imaged and left on the device, with film thicknesses of 4–100 µm in one coat and aspect ratios above 5:1. Soft bake, exposure, PEB and develop are all listed by film thickness rather than by grade, so the rows for SU-8 3005 are the ones that overlap its plotted thickness. Both thickness charts end at 4000 rpm and carry markers only at 1000, 2000, 3000 and 4000 rpm. Beyond those points the datasheet gives no thickness data for this grade. Fully cross-linked film is very hard to remove, so plan for that before choosing it as a sacrificial or temporary layer.

—07 / Family

Grades in this family

Other grades in the SU-8 3000 series line differ mainly in coating thickness:

SU-8 3000 series — grade comparison
GradeThickness
SU-8 3005 (this page)4.5–9.8 µm
SU-8 30108–18.8 µm
SU-8 302523–58 µm
SU-8 303524–87 µm
SU-8 305044.3–101.3 µm
—08 / Troubleshooting

Troubleshooting

Common failure modes for SU-8 3005, 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.

Is edge bead removal worth doing on a film as thin as SU-8 3005?

The datasheet describes the edge bead as a ridge of resist that builds up at the wafer rim during spin-coating and says to remove it with a thin stream of Kayaku's EBR PG solvent, aimed at the edge from above or from below. It gives two reasons: the ridge fouls the hotplate, and with it gone the mask can sit in closer contact with the wafer, which improves resolution and aspect ratio. Most automated coaters have an edge-rinse step built in.

SOURCE: Kayaku Advanced Materials "SU-8 3000 Permanent Negative Epoxy…

Kayaku Advanced Materials "SU-8 3000 Permanent Negative Epoxy Photoresist" technical data sheet (July 2020, Ver. 1) — Edge Bead Removal (EBR), p.3

How do I know the exposure was enough?

Look for a faint image of the mask on the film once the wafer is on the 95 °C PEB hotplate. The sheet says a correctly exposed film shows it within about 5–15 s of going on the plate and not before, and that it should be visible by 1 min of PEB. No latent image during or after the bake means too little dose, too little temperature, or both. Because the printed dose rows are ranges, the sheet recommends an exposure-matrix experiment to find the right value.

SOURCE: Kayaku Advanced Materials "SU-8 3000 Permanent Negative Epoxy…

Kayaku Advanced Materials "SU-8 3000 Permanent Negative Epoxy Photoresist" technical data sheet (July 2020, Ver. 1) — Exposure note, p.3; Post Exposure Bake note, p.4

My SU-8 3005 film is not the thickness I expected. Which chart applies?

The sheet prints two thickness-versus-speed charts, one for 21 °C (US and EU) and one for 23 °C (Japan and Asia), and the SU-8 3005 trace differs a little between them: about 9.8 µm versus 9.0 µm at 1000 rpm, with the order reversed by 4000 rpm (about 4.5 versus 5.6 µm). Use the chart for your region's material and cleanroom temperature, then confirm with a test wafer. Both charts are plotted from 1000 to 4000 rpm only.

SOURCE: Kayaku Advanced Materials "SU-8 3000 Permanent Negative Epoxy…

Kayaku Advanced Materials "SU-8 3000 Permanent Negative Epoxy Photoresist" technical data sheet (July 2020, Ver. 1) — Figure 1 and Figure 2, p.2

—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 3005 process recipe." NANYTE Photoresist Library. https://nanyte.com/photoresists/su-8-3005. Accessed 2026-10-15.

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