Microposit S1805 process recipe

MICROPOSIT S1805 G2 is the thinnest grade of the MICROPOSIT S1800 G2 positive photoresist series, coating roughly 0.41–0.67 µm — the pick when a design needs the series' finest single-layer film and tightest linewidth control rather than thickness.

https://nanyte.com/photoresists/s1805 · last updated 2026-07-26

At a glance

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Manufacturer: Rohm and Haas Electronic Materials
Tone: positive
Chemistry: DNQ-novolak

Coat
Soft bake
115 °C60 shotplate
Expose
Develop
TMAH or buffered alkaline

Substrate
Resist
Exposed

The exposed resist dissolves in the developer; the unexposed film stays. Schematic cross-sections for Microposit S1805 — feature width, film aspect ratio and sidewall angle are illustrative, not to scale.

—01 / Coating

Spin coating

Data points

Microposit S1805 — film thickness (µm) by spin speed (rpm)
Series	rpm	µm
S1805 G2	2000	0.67
	3000	0.55
	4000	0.50
	5000	0.47
	6000	0.44
	7000	0.41

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, 'MICROPOSIT S1800 G2 Photoresist Undyed Series Spin Speed Curves' (Figure 2), p.2 of MICROPOSIT S1800 G2 Series Photoresists datasheet (Rohm and Haas Electronic Materials, ME06N041, Rev. 0, October 2006); identified as the lowest of four plotted traces (cross marker, legend order S1818/S1813/S1811/S1805 top-to-bottom by thickness — the four curves do not cross across the plotted range); read at gridline/marker crossings every 1,000 rpm from 2,000–7,000 rpm off a linear-linear chart (thickness 0–40,000 Å, spin speed 1,000–8,000 rpm); no numeric table accompanies the figure so no independent point-value anchor exists in the document — visual chart-reading only, typical uncertainty ~10–15%.

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

Figure 2 ('MICROPOSIT S1800 G2 Photoresist Undyed Series Spin Speed Curves', p.2) plots four traces — S1818 G2, S1813 G2, S1811 G2, S1805 G2 — on one axis (spin speed 1,000–8,000 rpm vs photoresist thickness 0–40,000 Å), each carrying a distinct legend marker (diamond, triangle, square, cross respectively, in that order top-to-bottom by thickness) and, because the four curves do not cross across the plotted range, S1805 G2 (cross marker) is identified as the lowest trace at every spin speed.
The trace plotted here was read from gridline/marker crossings at 1,000 rpm intervals from 2,000–7,000 rpm; no numeric thickness-vs-rpm table accompanies the figure, so there is no independent point-value anchor and the values carry typical chart-reading uncertainty of about 10–15%.
Table 2 (p.2) records that Figure 2's coatings used an SVG 81 coater and a 115°C/60 sec hotplate softbake on silicon, measured on a Nanometrics 210 — that condition applies to this grade's trace and is recorded under softbake below.
The document states maximum coating uniformity is 'typically attained between the spin speeds of 3,500–5,500 rpm' (p.2, series-wide statement, not S1805-specific).
No rehydration hold or edge-bead handling is discussed anywhere in the document.

Adhesion: HMDS recommended — "MICROPOSIT S1800 G2 Series Photoresist work well with the hexamethyldisilazane-based MICROPOSIT Primers.

—02 / Bake

Soft bake

Soft bake: 115 °C · 60 s · hotplate
Notes: From Table 2 ('Process Conditions, Refer to Figure 2'): coat tool SVG 81, softbake 115°C/60 sec hotplate, measured on a Nanometrics 210.

SOURCE: Table 2, p.2 of MICROPOSIT S1800 G2 SERIES PHOTORESISTS, ME06N041, Rev. 0, October 2006

—03 / Exposure

Exposure dose

Every quantified exposure result on this sheet — sizing energy, contrast curve, exposure and focus latitude — was run on S1813 G2. For S1805 it gives only the series exposure window, 350 to 450 nm, optimized at 436 nm. Run a dose array on your own tool to land the working dose.

Not published for this resist: Dose at 365 nm, Dose at 405 nm — characterize on-tool.

—04 / Development

Development

Developer family: TMAH or buffered alkaline

—05 / Post-processing

Hard bake, etch & strip

Stripper: "Residue-free photoresist removal using standard MICROPOSIT removers" (ADVANTAGES section, p.1) — no specific remover product is named.
Storage: "Store products in tightly closed original containers at temperatures recommended on the product label." (STORAGE section, p.5) — no specific temperature is printed in the document itself.

—06 / Applications

Where it's used

Practical notes from the datasheet

This grade appears exactly once in the document: as the lowest of four traces (alongside S1811, S1813 and S1818 G2) on the undyed-series film-thickness-vs-spin-speed chart (Figure 2, p.2). Choose S1805 G2 over the thicker S1811, S1813 and S1818 grades when the process needs a thin resist layer and tight resolution rather than film thickness — on the same g-line process and develop chemistry it lays down the least film of the four. No dose, develop time, or lithographic-performance data (contrast curve, Dill parameters, absorbance spectrum, masking linearity, exposure/focus latitude — Figures 4–9, Tables 4–9) is published for S1805 specifically; every one of those figures and tables explicitly names MICROPOSIT S1813 G2 as the tested grade, and none of that data may be borrowed here. The document states the S1800 G2 system broadly is optimized for g-line (436 nm) exposure and usable across 350–450 nm, is compatible with HMDS-based MICROPOSIT primers, and works with both metal-ion-free (MF-319 family) and metal-ion-bearing MICROPOSIT developers, but none of those statements carry an S1805-specific number. This recipe replaces an earlier extraction made from the superseded circa-1993 Shipley 'MPR S1800 1093' edition, per a WL decision on 2026-07-10; the S1800 line traces from Shipley through Rohm and Haas Electronic Materials (publisher of this G2 edition) to Dow, DuPont, and today's Kayaku Advanced Materials. Chemistry classified as dnq-novolak from the Dow/Rohm and Haas S1818 MSDS composition table (mixed cresol novolak resin + diazo photoactive compound) and Kayaku's S1800 G2 series-wide statement.

—07 / Family

Grades in this family

Other grades in the MICROPOSIT S1800 G2 Series line differ mainly in coating thickness:

MICROPOSIT S1800 G2 Series — grade comparison
Grade	Thickness	Exposure dose
S1813	1.0–1.9 µm	150 mJ/cm² @ 436 nm
Microposit S1805 (this page)	—	—
Microposit S1818	—	—
S1822	—	—

—08 / Troubleshooting

Troubleshooting

Common failure modes for Microposit S1805, 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.

How thick a film does MICROPOSIT S1805 G2 coat?

S1805 G2 is the thinnest of the four undyed S1800 G2 grades. On the Figure 2 spin-speed chart its trace runs from about 0.67 µm at 2,000 rpm down to 0.41 µm at 7,000 rpm. Maximum coating uniformity is typically attained between 3,500 and 5,500 rpm (a series-wide statement). These points are a figure read with roughly ±10–15% uncertainty, so confirm the target thickness on-tool.