EUV Lithography Mask Technology 2026 — PatSnap Eureka
EUV Lithography Mask Technology Landscape 2026
Extreme ultraviolet lithography mask technology sits at the critical junction between semiconductor scaling ambitions and physical manufacturing limits, enabling pattern transfer at 13.5 nm wavelength using reflective optical architectures. This report covers the patent and literature landscape across mask blank production, absorber engineering, phase-shift designs, and defect inspection.
How EUV Masks Work: Reflective Architecture at 13.5 nm
EUV lithography masks operate on a reflection principle: EUV radiation at 13.5 nm wavelength is absorbed by virtually all materials, so the mask cannot transmit light as in conventional optical lithography. Instead, a multilayer (ML) stack — typically alternating molybdenum and silicon bilayers — is deposited on an ultra-low thermal expansion material (LTEM) substrate to form a Bragg reflector. An absorber layer patterned on top of the ML stack defines the circuit pattern by selectively blocking EUV reflectance.
A capping layer, commonly ruthenium, protects the ML stack from oxidation and cleaning damage. The core technical sub-domains covered in this landscape include mask blank production systems, absorber layer chemistry, phase-shifting mask architectures, reflective mask blank engineering, on-axis illumination patterning, and defect inspection and repair. For context on the broader semiconductor manufacturing ecosystem, see PatSnap IP Analytics.
EUV achieved high-volume manufacturing readiness in 2018 with greater than 250 W source power and greater than 140 wafers per hour throughput, as confirmed in literature. The technology was deployed for 7 nm node production in 2018 and is required for 5 nm and below. DRAM manufacturing at 16 nm half-pitch also uses EUV masks, with overlay requirements below 1.1 nm matched-machine overlay and CD uniformity below 0.5 nm full-wafer. For semiconductor manufacturing IP intelligence, PatSnap provides global patent coverage across 120+ countries.
This landscape is derived from a limited set of patent and literature records retrieved across targeted searches. It represents a snapshot of innovation signals within this dataset only and should not be interpreted as a comprehensive view of the full industry. The global standards body IEEE and the European Patent Office provide additional context on semiconductor IP filing norms.
From Proof-of-Concept to High-NA EUV: Filing Activity by Phase
Patent filing density in this dataset reveals four distinct innovation phases from 2006 to 2026, with the highest filing density falling between 2013 and 2017.
Filing Activity by Phase (2006–2026)
The 2013–2017 development phase shows peak filing density; the most recent phase (2023–2026) shows renewed activity for high-NA EUV.
Jurisdiction Distribution of EUV Mask Patents
The US dominates with roughly 80% of retrievable records; EP, SG, WO, and MY account for the remainder.
Four Technology Clusters Defining the EUV Mask Landscape
The patent dataset organises into four distinct clusters, each addressing a different layer of the EUV mask stack or its quality assurance infrastructure.
Conventional Binary Absorber Mask Blanks
The dominant conventional architecture uses an LTEM substrate, a Mo/Si multilayer Bragg reflector, a ruthenium capping layer, and a tantalum-based absorber (TaN, TaON, or TaBN). Absorber thickness of less than 80 nm and reflectivity below 2% at 13.5 nm are key specifications. Applied Materials developed an integrated vacuum production system to deposit both the ML stack and absorber in a single handling pass, eliminating contamination risks. PatSnap IP Analytics maps the full competitive landscape for these production systems.
Absorber <80 nm · Reflectivity <2% at 13.5 nmPhase-Shifting Mask Designs
Phase-shift masks exploit the EUV phase relationship between adjacent pattern regions to achieve contrast enhancement. TSMC’s approach uses two-state masks with 180-degree phase difference combined with near-on-axis illumination (partial coherence σ < 0.3), selectively passing only ±1st diffraction orders. S&S Tech Co., Ltd. has developed blankmasks with dedicated phase-shift films using niobium–chromium (Nb/Cr) first layers and tantalum–silicon (Ta/Si) second layers, achieving higher NILS and lower dose-to-clear (DtC) metrics than binary masks.
Partial coherence σ < 0.3 · Higher NILSNovel Absorber Chemistries for 3D Effect Mitigation
The “mask 3D effect” — in which the finite absorber stack height causes shadowing and telecentricity errors under oblique EUV illumination — becomes increasingly problematic at tighter nodes. S&S Tech Co., Ltd. is the primary assignee pursuing non-tantalum absorber chemistries, specifically chromium–antimony (CrSb) films with compositions of Cr 30–60 at%, Sb 40–70 at%, N 0–20 at%. CrSb absorbers achieve the required optical properties at reduced film thickness, directly reducing the 3D effect and improving dose-to-space (DtS) and NILS metrics. For materials IP intelligence, see PatSnap for Chemicals.
CrSb: Cr 30–60 at%, Sb 40–70 at%Defect Inspection, Metrology, and Mask Repair
Defect-free masks remain a critical bottleneck. Inspection approaches include projection electron microscopy (PEM), coherent diffractive imaging (CDI/ptychography) at EUV wavelength (actinic inspection), and scatterometry combined with finite element analysis for absorber profile reconstruction. For repair, electron-beam-induced processing (FEBIP) is the state-of-the-art method, with sub-10 nm extrusion repair demonstrated using the next generation MeRiT LE tool. No mass-production actinic inspection tool is commercially established. The NIST and EPO provide supplementary metrology standards context.
Sub-10 nm FEBIP repair · Actinic CDIPrimary Patent Assignees and Filing Strategies
Five primary assignees account for nearly all filings in this dataset, with activity highly concentrated rather than distributed across the broader industry.
| Assignee | Records (approx.) | Jurisdictions | Focus Area | Filing Period |
|---|---|---|---|---|
| TSMC | 25+ records | US (dominant) | Process & mask design: near-on-axis illumination, phase-shifting, LEUVR mask pairs, shadow effect reduction | 2013–2021 |
| Applied Materials, Inc. | ~15 records | US, WO, EP, SG, MY | EUV mask blank production systems; vacuum-integrated deposition platforms | 2016–2023 |
| AGC Inc. | ~12 records | US (dominant), SG | Reflective mask blank material compositions: low-reflective layers, absorber layers, hard mask layers | 2011–2025 |
Five Technology Vectors Shaping High-NA EUV Mask Innovation
Based on the most recent filings in this dataset (2023–2026), five directions are clearly emerging for next-generation EUV mask technology.
CrSb-Based Thin Absorber Films
S&S Tech’s 2025 filings in US, EP, and SG for CrSb(N,O,C) absorbers represent a significant departure from the tantalum absorber paradigm. CrSb enables thinner absorber stacks, directly reducing the 3D mask effect that becomes critical for high-NA EUV (NA > 0.55). Compositions: Cr 30–60 at%, Sb 40–70 at%, N 0–20 at%.
Advanced Phase-Shift Blankmasks with Multi-Element Films
S&S Tech’s 2026 US filing with Ru-containing phase-shift films and Nb/Cr etch-stop layers, and companion filings with Nb/Cr + Ta/Si bilayer architecture, indicate a push toward multi-film phase-shift stacks tuned for high-NA EUV imaging metrics including NILS, DtC, and DtS.
Multilayer Absorber Stacks
Applied Materials’ 2023 US filing introduces a multilayer absorber concept — multiple absorber layer pairs replacing a single monolithic layer — potentially enabling composition grading and improved optical performance across the absorber stack depth.
Fully Reflective Absorber-Free Mask Architectures
TSMC’s 2021 US patent on a fully reflective phase-edge mask — using trenched patterned multilayers with no separate absorber layer — points toward a future where the absorber is eliminated entirely, removing 3D effects at their source.
Where EUV Mask Technology Is Applied Across the Semiconductor Value Chain
EUV mask technology serves four distinct application domains, from leading-edge logic to research infrastructure.
EUV Lithography Mask Technology — key questions answered
EUV lithography operates at 13.5 nm wavelength. At this wavelength, EUV radiation is absorbed by virtually all materials, so the mask cannot transmit light as in conventional optical lithography and instead uses a reflective multilayer stack.
The mask 3D effect refers to shadowing and telecentricity errors caused by the finite absorber stack height under oblique EUV illumination. It becomes increasingly problematic at tighter nodes. Thinner absorber materials such as CrSb directly reduce this effect.
TSMC is the single most prolific assignee with more than 25 distinct patent records, followed by Applied Materials with approximately 15 records, AGC Inc. with approximately 12 records, and S&S Tech Co., Ltd. with approximately 8 records filed from 2022 onward.
A phase-shift blankmask exploits the EUV phase relationship between adjacent pattern regions to achieve contrast enhancement. TSMC’s approach uses two-state masks with 180-degree phase difference combined with near-on-axis illumination (partial coherence sigma less than 0.3). S&S Tech uses niobium-chromium and tantalum-silicon bilayer phase-shift films achieving higher NILS and lower dose-to-clear metrics than binary masks.
Actinic inspection refers to mask inspection performed at the EUV operating wavelength (13.5 nm), using tools based on synchrotron or high-order harmonic generation sources with coherent diffractive imaging or ptychographic reconstruction. No mass-production actinic inspection tool is commercially established as of this dataset.
CrSb (chromium-antimony) absorbers are a non-tantalum alternative absorber chemistry developed by S&S Tech Co., Ltd., with compositions of Cr 30-60 at%, Sb 40-70 at%, and N 0-20 at%. They achieve the required optical properties at reduced film thickness, directly reducing the 3D mask effect that becomes critical for high-NA EUV (NA greater than 0.55).
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