https://nanyte.com/photoresists/ar-n-4340 · last updated 2026-09-28
- Manufacturer
- Allresist
- Tone
- negative
- Chemistry
- Chemically amplified
- Thickness
- 1.2–4.2 µm
- Exposure dose
- 140 mJ/cm² (E0, broadband stepper)
- Developer
- AR 300-475
- Applications
- Etch mask · Lift-off
Human-verified — checked against the manufacturer's datasheet by a person.
- Substrate
- Resist
- Exposed
Spin coating
Data points
| Series | rpm | µm |
|---|---|---|
| AR-N 4340 | 500 | 4.2 |
| 1000 | 3.0 | |
| 2000 | 2.1 | |
| 3000 | 1.7 | |
| 4000 | 1.5 | |
| 5000 | 1.3 | |
| 6000 | 1.2 |
Values are the manufacturer’s starting points, not a guarantee — characterize on your own tool. Series digitized from a published figure are approximate (±10 %).
read from figure, 'Spin curve' (D₀/µm 0.0–5.0 vs rpm 0–8000), p.50 of Allresist AR-N 4300 product-information sheet (as of January 2014); single-grade chart, one legended trace labeled 'AR-N 4340' — no curve-identification ambiguity. Seven diamond markers are plotted, at rpm 500/1000/2000/3000/4000/5000/6000; the fitted line continues unmarked to 8000 rpm at ~1.05 µm, and that tail carries no discrete marker so it is not read as a point. The figure's 4000 rpm marker reads ≈1.47 µm, about 5% above the Properties I table's printed 'Film thickness/4000 rpm (µm): 1.4' (p.50, cross-referenced by the Coating box, p.51: '4000 rpm, 60 s, 1.4 µm') — the table value is the more authoritative single number, the figure read close but not exact.
- Spin-speed-vs-thickness figure ('Spin curve', p.50, axes D₀/µm 0-5.0 vs rpm 0-8000) is a single-grade chart: one legended AR-N 4340 trace with 7 diamond markers from 500-6000 rpm, anchored against the Properties I table's 4000 rpm -> 1.4 µm reference point (the figure's own 4000 rpm marker reads ≈1.47 µm, a ~5% deviation from the table value — both are recorded).
- No dispense volume, acceleration ramp, or edge-bead-removal step is described anywhere in this document.
- Adhesion
- Datasheet specifies Allresist's own adhesion promoter AR 300-80 (Process chemicals table, p.50); does not mention HMDS specifically either way. 'Good adhesion' is listed as a general Characteristic (p.50).
Soft bake
- Soft bake
- 90 °C · 60 s · hotplate
- Notes
- ± 1 °C tolerance. Alternative: 85 °C, 25 min (1500 s) convection oven. Datasheet calls this step 'Softbake' in the Process conditions diagram and 'Tempering' in the Process parameters table (85 °C, 60 s, hot plate — note this table gives a slightly different temperature, 85 °C not 90 °C, for the same nominal step; both are reproduced here for transparency).
SOURCE: Process conditions diagram, p.51; Process parameters table, p.50
Exposure dose
The manufacturer publishes 140 mJ/cm² (E0, broadband stepper). Dose scales with film thickness and depends on your optics, so treat it as a starting point and run a dose array.
- As published
- 140 mJ/cm² is a clearing dose, not a process dose: it is the energy that just clears a 1.4 µm film on a broadband stepper carrying 365, 405 and 436 nm together. No single-wavelength number is published.
- Post-exposure bake
- 95 °C · 2 min
Not published for this resist: Dose at 365 nm, Dose at 405 nm — characterize on-tool.
SOURCE: Process conditions diagram, p.51 of Allresist AR-N 4300 series…
Process conditions diagram, p.51 of Allresist AR-N 4300 series product information (English); dose stated as "Exposure dose (E0, broadband UV stepper): 140 mJ/cm², 1.4 µm".
Development
- Developer
- AR 300-475
- Dilution
- Not published — characterize on-tool
- Time
- 60 s
- Method
- puddle
- Rinse
- DI-H2O, 30 s
- Developer family
- TMAH or buffered alkaline
SOURCE: Process conditions diagram, p.51; Process parameters table, p.50
Hard bake, etch & strip
- Etch resistance
- "Plasma etching resistant, temperature-stable up to 220 °C after subsequent treatment" (Characteristics, p.50). Plasma etching rates (5 Pa, 240-250 V Bias, Properties II table, p.50): Ar-sputtering 8 nm/min, O2 173 nm/min, CF4 33 nm/min, 80% CF4 + 16% O2 93 nm/min.
- Stripper
- AR 300-76 or AR 300-72 (Process chemicals table, p.50); alternatively AR 300-76 or O2 plasma ashing per the Process conditions diagram, p.51.
- Storage
- "Storage 6 month (°C): 10 - 18" (Properties I table, p.50) — i.e. a 6-month shelf life is stated when stored at 10-18 °C.
Not published for this resist: Hard bake, Descum — characterize on-tool.
SOURCE: Process conditions diagram, p.51
Where it's used
Practical notes from the datasheet
AR-N 4340 is Allresist's highly sensitive negative-tone photoresist in the AR-N 4300 series, described as 'novolac with photochemical acid generator and amine-based crosslinking agent' — a chemically amplified negative chemistry (mapped here to the 'car' enum value) rather than the older bisazide-novolak crosslinking chemistry used in resists like ma-N 1400. Development strongly depends on the crosslinking-bake temperature: the datasheet's own TCD table shows optimum crosslinking-bake temperatures of 90-100 °C, with clearing dose rising sharply outside that window (480 mJ/cm² at 70 °C vs. 65 mJ/cm² at 100 °C) and the resist becoming completely undevelopable above 130 °C. Undercut (lift-off) profiles are obtained not by underexposing but by extending development time at the resist's minimum clearing dose, per the datasheet's explicit recommendation. The published exposure dose (140 mJ/cm² for a 1.4 µm film) is a broadband figure spanning i-line/h-line/g-line together (365/405/436 nm) rather than a single-wavelength dose, so it is recorded as an unattributed value rather than filed under either the i-line or h-line field — a separately mentioned i-line-only stepper configuration (NA 0.65) is given no dose at all. A single-grade spin-speed-vs-thickness figure exists in the datasheet (0-8000 rpm, 0-5 µm), but only the exact 4000 rpm -> 1.4 µm anchor from the accompanying numeric table is published here as structured data; additional curve points should be read directly from the source figure by a human reviewer.
Troubleshooting
Common failure modes for AR-N 4340, 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.
My AR-N 4340 dose and develop time drift between runs — how sensitive is the crosslinking bake?
Very. The datasheet's table (samples dried at 85 °C, developed in AR 300-475) shows the dose needed moving from 480 mJ/cm² at a 70 °C crosslinking bake to 140 at 90 °C and 65 at 100 °C, while clearing time rose from 24 s at 90 °C to 41 s at 100 °C. At 120 °C clearing took 210 s, and above 130 °C the film no longer develops at all. Hold the bake at 95 °C for 2 min on a hotplate, within the stated ±1 °C, and inside the 90–100 °C optimum.
SOURCE: AR-N 4300 product information
AR-N 4300 product information (Allresist) — Process conditions: Crosslinking bake, and TCD vs. bake temperature table, p.51
AR-N 4340 unexposed areas won't clear, or clear far too slowly — what happened?
Check the crosslinking-bake temperature first. The datasheet shows clearing time climbing to 210 s after a 120 °C bake, and above 130 °C the resist cannot be developed at all, so a hotplate running hot will do this. Next, check the developer. The datasheet develops in AR 300-475 for 60 s puddle at 21–23 °C (±0.5 °C), and also lists AR 300-26 at 1:1 or AR 300-35 undiluted. A stronger developer makes a negative resist need more dose to crosslink; a weaker one needs less dose but takes longer.
SOURCE: AR-N 4300 product information
AR-N 4300 product information (Allresist) — Process conditions, Development recommendations and TCD vs. bake temperature table, p.51; FAQs concerning photoresists (Allresist, 03.03.2016) — Question 10, p.10
How do I get a lift-off undercut from AR-N 4340?
Use the lowest exposure dose that still holds the pattern, then extend the development time. The datasheet says that combination gives an undercut resist profile suitable for lift-off. Its reference develop is AR 300-475 for 60 s puddle, so lengthen from there in steps and section a test wafer. The datasheet does not publish a target undercut or an over-develop percentage for this resist. The optional hardening step (150 mJ/cm² flood, then 115 °C for 1 min) is for structures that must survive up to 300 °C.
SOURCE: AR-N 4300 product information
AR-N 4300 product information (Allresist) — Process conditions: Development note and Hardening of structures, p.51; Characterisation, p.50
My AR-N 4340 film floats off in concentrated HCl — is that expected?
Yes. In Allresist's acid-resistance tests, concentrated 37 % HCl showed no reaction with the resist films, but AR-N 4340 is the one they single out for adhesion problems: the film floats off after about 10 min. Keep etches in concentrated HCl well under that, and prime with AR 300-80, the adhesion promoter listed for this resist.
SOURCE: pp.14–15 AR-N 4300 product information
FAQs concerning photoresists (Allresist, 03.03.2016) — Question 18, pp.14–15; AR-N 4300 product information (Allresist) — Process chemicals, p.50
I see bubbles in AR-N 4340 after exposure — is it outgassing like a DNQ positive resist?
No. Allresist states that AR-N 4300 and 4400 resists develop no gas bubbles on exposure, because they contain no gas-forming components. Look for air or solvent instead. Air gets in when the bottle has been shaken or moved, or opened cold; open the lid slightly and let the bottle stand a few hours first. Residual solvent comes from a softbake that is too short or too cool. The datasheet softbake is 90 °C for 1 min on a hotplate, or 85 °C for 25 min in a convection oven.
SOURCE: pp.5–7 AR-N 4300 product information
FAQs concerning photoresists (Allresist, 03.03.2016) — Questions 6–7, pp.5–7; AR-N 4300 product information (Allresist) — Process conditions: Softbake, p.51
Sources & disclaimer
- Allresist — AR-N 4340 datasheet (p.50: 'As of January 2014'; p.51: 'As of January 2016' (the two pages of this two-page spread carry different revision dates as printed)) · accessed 2026-07-10
- https://www.allresist.com/portfolio-item/developer-ar-300-475/ — Allresist's own product page for developer AR 300-475: gives its main component as TMAH and its metal-ion content as under 0.1 ppm. Read together with the AR 300-26 page (sodium borate / sodium hydroxide) and the AR 300-35 page (sodium metasilicate / phosphate), it establishes that the developers this resist's own "Development recommendations" table offers span both a metal-ion-free and a metal-ion-containing chemistry.
- Cao et al.. Multi-photon laser lithography of AR-N 4340 photoresist with a spatial resolution at nanoscale. Proc. SPIE 10842, 9th International Symposium on Advanced Optical Manufacturing and Testing Technologies: Subdiffraction-limited Plasmonic Lithography and Innovative Manufacturing Technology (2019). doi:10.1117/12.2506365Direct-write multi-photon laser lithography of AR-N 4340, reporting nanoscale spatial resolution. Relevant here because it exercises this chemically amplified negative resist under focused-laser direct writing rather than the mask-aligner exposure the datasheet describes.
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 2026-09-28.