China Invests €37 Billion to Develop Domestic EUV Lithography Systems
EUV (Extreme Ultraviolet) lithography systems play a vital role in semiconductor manufacturing, facilitating the creation of smaller, more powerful, and energy-efficient chips.
EUV (Extreme Ultraviolet) lithography systems are crucial for manufacturing innovative semiconductors, enabling the production of smaller, more powerful, and energy-efficient chips. Using a 13.5 nm wavelength light to pattern extremely fine features on semiconductor wafers, EUV is essential for delivering nodes at 5 nm, 3 nm, and beyond.
ASML, a Dutch company, is the only manufacturer of EUV systems, which makes them crucial for world semiconductor production. Access to these machines is strictly limited, and export limits affect political and economic influence.
Under U.S. pressure, ASML has been prohibited from selling its advanced equipment to China since 2019. Recently, the Netherlands further tightened these restrictions, effectively blocking China’s access to essential components.
This article will explore China’s bold €37 billion semiconductor initiative to develop domestic EUV lithography systems and the possible threat it poses to ASML’s market leadership.
ASML’s monopoly on EUV technology
EUV lithography, pioneered by ASML, is the only technology capable of achieving the precision required for next-generation semiconductor manufacturing. This capability is critical for sustaining the semiconductor industry’s ability to follow Moore’s Law—the decades-old trend of doubling the number of transistors on a chip roughly every two years.
The process begins with the generation of EUV light, a feature achieved by targeting microscopic tin droplets with high-power lasers. The intense energy converts the tin into a plasma, which emits the required 13.5 nm wavelength light. Because EUV light is readily absorbed by air and conventional materials, the entire process occurs in a vacuum, and specialized optics are required to direct the light.
These optics rely on mirrors coated with alternating layers of molybdenum and silicon, engineered to reflect EUV light through constructive interference. The mirrors must be polished to near-perfect smoothness, as imperfections as small as a nanometer could disrupt the precision required for chip fabrication.
Equally crucial are the photoresists, light-sensitive materials applied to silicon wafers. These resists must be finely tuned to react to EUV’s short wavelength, balancing sensitivity and resolution to minimize defects. Innovations in resist chemistry have been pivotal to advancing EUV’s practicality.
Figure 1 shows the full optical light path, inside the ASML’s TWINSCAN NXE equipment, from the EUV source (bottom right) to the semiconductor wafer (mid-bottom).
EUV lithography allows the production of smaller, faster, and more energy-efficient chips powering innovative applications, such as artificial intelligence (AI), 5G networks, high-performance computing, and autonomous systems. Industry leaders like TSMC, Samsung, and Intel use EUV systems (exclusively produced by ASML) to maintain their competitive edge.
EUV vs. DUV
Without EUV, scaling transistors to current densities would be impossible using older deep ultraviolet (DUV) lithography methods. DUV and EUV lithography differ significantly in wavelength and resolution. DUV operates at longer wavelengths, typically 248 nm with KrF lasers or 193 nm with ArF lasers. Advanced techniques such as immersion lithography, which uses water to enhance resolution, and multiple patterning, where multiple exposures enable finer features, allow DUV to handle nodes down to approximately 7 nm.
In contrast, EUV functions at a much shorter wavelength of 13.5 nm, making it possible to pattern features below 7 nm, including 5 nm and 3 nm nodes, in a single exposure. This eliminates the need for complex multi-patterning.
In terms of applications, DUV dominates across nodes ranging from approximately 180 nm to 7 nm and is widely used in the production of memory chips such as DRAM and NAND, as well as less advanced logic chips. EUV, however, is essential for advanced logic nodes of a few nanometers, particularly in high-performance CPUs and GPUs. While EUV is used for critical layers, such as metal layers, some layers still rely on DUV for cost efficiency.
High-NA EUV
ASML further expanded the capabilities of EUV lithography developing the high numerical aperture (NA) technology, also known as ‘EXE’. In high-NA lithography systems, the numerical aperture (a measure of the ability of an optical system to collect and focus light) is increased from 0.33 to 0.55. That reduces the critical dimension, or the smallest feature the system can print, by 1.7 times and increases the transistor density on a chip by 2.9 times.
Key players in China’s EUV development
Numerous Chinese companies are working toward this ambitious goal, led by Huawei, which in 2022 filed a patent for a new type of EUV light source. Another major player, SMEE (Shanghai Micro Electronics Equipment), China’s leading photolithography equipment manufacturer, filed a 2023 patent titled “Extreme Ultraviolet Radiation Generators and Lithography Equipment.”
Academia has also joined the race. The Harbin Institute of Technology recently proposed an alternative approach to generating EUV light, distinct from Western methods. The institute’s project, led by Professor Zhao Yongpeng, focuses on a discharge-induced plasma EUV source with a central wavelength of 13.5 nanometers.
ASML’s EUV light source employs the laser-produced plasma (LPP) technique, where high-energy lasers strike liquid tin droplets to generate plasma. This process depends on advanced laser components and sophisticated FPGA-based control, with key technologies historically dominated by foreign firms.
In contrast, Zhao’s team adopts the laser-induced discharge plasma (LDP) approach. In this method, a laser vaporizes a small quantity of tin, forming a cloud between two electrodes. A high voltage is then applied across the electrodes, energizing the tin cloud and transforming it into plasma. The resulting interactions between electrons and high-valence tin ions produce EUV light.
According to the institute’s website, this approach boasts “high energy conversion efficiency, low cost, compact size, and relatively low technical complexity.” However, optimizing discharge pulse timing and output power remains a significant challenge.
Other research groups in China are also exploring EUV technology from various angles. The Shanghai Institute of Optics and Fine Mechanics, along with Tsinghua University, is spearheading the SSMB-EUV project, a large-scale national initiative aimed at developing an alternative EUV light source for lithography.
China’s challenges in breaking ASML’s monopoly
Despite China’s €37 billion investment, it is unlikely to produce commercially viable 13.5 nm EUV lithography machines within a few years. ASML operates as a system integrator, relying on an ecosystem of cutting-edge intellectual property and components, the vast majority of which come from Western suppliers with decades of expertise. Moreover, beyond the core light source system, producing a complete lithography machine also demands high-precision components like mirrors.
Additionally, research efforts continue to focus on improving energy efficiency, an area where recent breakthroughs promise substantial gains. Professor Tsumoru Shintake from the Okinawa Institute of Science and Technology (OIST) has proposed an EUV technology that could reduce energy consumption by 90%. ASML, too, has introduced significant upgrades to improve both efficiency and productivity in its systems.
OIST’s EUV lithography design enables operation with smaller EUV light sources, significantly lowering costs while greatly enhancing machine reliability and lifespan. Additionally, it consumes less than one-tenth the power of traditional EUV lithography systems, contributing to a more environmentally sustainable semiconductor industry.
This breakthrough was achieved by overcoming two challenges once thought insurmountable (Figure 2). The first is the development of an innovative optical projection system utilizing just two mirrors. The second is a novel approach to efficiently directing EUV light onto logic patterns on a flat mirror (the photomask) without obstructing the optical path.
The road ahead
China’s bid to develop EUV lithography represents one of the most ambitious technological initiatives in recent history. While progress is being made, the country faces immense technical, intellectual property, and supply chain challenges. Overcoming ASML’s decades-long head start will not be easy, but China’s determination—backed by massive funding—ensures that the global semiconductor race is far from over.
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