The semiconductor industry continues to push the limits of miniaturization, performance, and power efficiency. One of the critical advancements enabling this evolution is the adoption of extreme ultraviolet (EUV) lithography. This shift has had a profound impact on various sectors of the semiconductor ecosystem, and none more so than the photomask market. As chipmakers transition toward manufacturing at nodes below 7nm, the role of EUV technology becomes central—and with it, photomasks must evolve to meet the demands of high-resolution, defect-free patterning.

The photomask market involves the production of high-precision plates that contain the circuitry patterns used in semiconductor fabrication. These masks are placed over silicon wafers during the lithography process to etch intricate circuit patterns. In traditional deep ultraviolet (DUV) lithography, multiple masks and exposures are often required to define complex features. EUV lithography, by contrast, allows for single-pattern exposures at significantly smaller wavelengths (13.5 nm), enabling simpler processes and tighter features—but it introduces new complexities for photomask design, production, and inspection.

According to recent industry reports, the global photomask market was valued at over USD 4.8 billion in 2022 and is projected to surpass USD 6.5 billion by 2028, growing at a CAGR of around 5%. The EUV photomask segment is expected to be the fastest-growing category, driven by increasing investments from major foundries such as TSMC, Samsung, and Intel, who are racing to perfect EUV-based manufacturing for advanced nodes like 5nm, 3nm, and beyond.

Adapting to EUV: What’s Changing in the Photomask Market?

The adoption of EUV lithography is not a simple plug-and-play upgrade. It brings fundamental changes in how photomasks are designed, manufactured, inspected, and used in semiconductor fabs. Here’s a deep dive into how the photomask industry is adapting to this next-generation lithography technology.

1. Shift from Conventional to EUV Mask Materials

Traditional DUV masks are made using fused silica substrates with chrome-based absorber layers. However, EUV masks require a completely different construction. EUV masks are based on reflective optics rather than transmissive optics, using multi-layered molybdenum-silicon (Mo/Si) substrates to reflect EUV light. This change necessitates new materials, new deposition techniques, and rigorous control of mask flatness and layer uniformity.

2. Higher Precision in Mask Defect Control

EUV masks are extremely sensitive to defects, and even minor imperfections can lead to yield loss in wafer production. Unlike DUV lithography, where some defects can be compensated for using optical proximity correction (OPC), EUV requires nearly defect-free masks. This has led to significant investment in advanced mask inspection tools, actinic inspection technologies (which use EUV light), and high-resolution e-beam inspection systems to detect and mitigate defects at the nanoscale.

3. Need for Mask Pellicles in EUV

One of the most critical challenges in EUV lithography is mask contamination. EUV pellicles are ultra-thin membranes used to protect the mask from particles during exposure. However, developing pellicles that can withstand EUV energy levels while maintaining transparency and thermal durability has proven difficult. Recent advancements in pellicle materials, including silicon nitride and carbon-based films, are enabling limited deployment of pellicles in high-volume EUV production.

4. Introduction of Computational Lithography

To enhance pattern fidelity in EUV masks, computational lithography techniques such as inverse lithography and model-based OPC are being adopted. These methods involve complex algorithms that simulate how light interacts with the mask and wafer to predict and correct distortions. This shift requires not only greater design expertise but also close collaboration between EDA tool vendors and photomask manufacturers.

5. Rising Demand for Mask Blanks and Writing Tools

The increased complexity of EUV masks has boosted demand for high-grade mask blanks—substrates used as the base for mask fabrication. At the same time, the industry is seeing rising investment in e-beam writing tools capable of producing EUV mask patterns with nanometer accuracy. Companies like NuFlare, IMS Nanofabrication, and JEOL are playing a critical role in supplying advanced mask writing solutions.

6. Enhanced Mask Inspection and Repair Capabilities

As EUV masks require near-zero defect tolerance, mask inspection and repair technologies are also evolving. Tools that use e-beam imaging for mask metrology are now essential, along with actinic review tools that inspect masks under actual EUV wavelengths. Mask repair systems must also be able to correct absorber and multilayer defects with extreme precision, often using focused ion beam or gas-based repair techniques.

7. Increased Collaboration Across the Supply Chain

The complexity of EUV masks has fostered tighter collaboration between semiconductor foundries, photomask vendors, EDA companies, and equipment suppliers. Mask shops now work closely with chip designers to align mask specifications with wafer process requirements, ensuring that final patterns meet both design intent and manufacturability standards. This integrated development model is key to reducing turnaround times and improving mask yield.

8. Rising Costs and Longer Lead Times

One of the major implications of EUV adoption in photomasks is the increased cost and complexity of mask production. EUV masks can cost several times more than traditional masks, with production lead times stretching from weeks to months. This has led to the development of mask cost-sharing models, mask reuse strategies, and multi-die reticle designs to reduce cost per function.

9. Focus on Sustainability and Mask Reusability

With the increased cost and energy demand of producing EUV masks, sustainability is becoming a priority. The industry is exploring ways to reuse and refurbish masks through advanced cleaning, re-coating, and re-certification processes. Additionally, low-defectivity materials and eco-efficient mask writing tools are helping to reduce environmental impact.

10. Regional Expansion and Investment

The growing strategic importance of semiconductor manufacturing has prompted governments and private companies to invest heavily in domestic mask production capabilities. Regions like the United States, South Korea, Japan, and the EU are funding R&D projects and establishing mask centers of excellence to reduce reliance on foreign suppliers and ensure resilience in the semiconductor supply chain.

Recent Developments in EUV Photomask Technology

• In 2023, ASML announced new collaborations with mask suppliers to develop next-generation EUV pellicles with improved transmission and thermal properties.
  
• TSMC has ramped up its 3nm production using EUV with defect-free mask qualification, showcasing the maturity of EUV masks in high-volume manufacturing.
  
• Global photomask leader Photronics is investing in a new EUV mask facility in Taiwan, aimed at serving top-tier chipmakers with cutting-edge solutions.
  

These milestones highlight how the industry is not just adapting but thriving amid the transition to EUV.

Benefits of EUV-Compatible Photomasks

• Enable high-resolution patterning for 5nm, 3nm, and future nodes
  
• Reduce the number of mask layers needed per chip design
  
• Improve yield and uniformity in critical layers
  
• Support faster time-to-market for advanced chips
  
• Enhance overall lithography accuracy and performance
  

By enabling smaller features and greater design complexity, EUV-compatible masks are pushing the boundaries of Moore’s Law and unlocking new opportunities in AI, 5G, automotive, and edge computing applications.

Frequently Asked Questions

Q1. Why are EUV photomasks more complex than traditional ones?

A. EUV photomasks are reflective rather than transmissive and must maintain nanometer-level precision to prevent defects from being printed on wafers. Their multilayer structure and extreme sensitivity to particles make them significantly more complex to design, inspect, and manufacture.

Q2. What is a pellicle, and why is it important in EUV lithography?

A. A pellicle is a thin protective membrane placed over a photomask to shield it from particles during exposure. In EUV lithography, pellicles must transmit EUV light effectively without distorting the pattern, and must also withstand the intense heat generated during the process, making their development extremely challenging and essential.

Q3. How does EUV technology impact the cost of photomask production?

A. EUV mask production is significantly more expensive due to the need for advanced materials, ultra-precise fabrication tools, defect-free requirements, and specialized inspection systems. However, EUV also reduces the number of total masks needed per chip, potentially offsetting some of the cost increases.