Among them, BYD, as one of China's largest lithography machine suppliers, has achieved world-leading levels in the precision and stability of its products, making it a significant force in the global lithography machine market. Additionally, Huawei's chip company, established in 2018, is also vigorously promoting the research and development of lithography machine-related technologies to achieve independent production and supply, contributing to the global market entry of domestically produced chips.
However, China's lithography machine industry still faces some challenges, such as relatively weak domestic R&D capabilities, high dependence on imported key components, difficulty in meeting high-end market demands, and relatively lagging product technology. Therefore, China's lithography machine industry will face both challenges and opportunities for a considerable period, requiring strengthened technological R&D, enhanced international cooperation, and an open and sharing approach to accelerate its development.
Photolithography is one of the core technologies in semiconductor manufacturing. It uses a light source of a specific wavelength to create tiny circuit patterns on the surface of a wafer. As semiconductor processes continue to evolve towards higher integration, lower power consumption, and higher performance, photolithography also faces challenges such as continuously improving resolution, reducing costs, and increasing production capacity.
Currently, the most advanced lithography technology globally is EUV (Extreme Ultraviolet) lithography, which uses an extreme ultraviolet light source with a wavelength of 13.5nm and can achieve process nodes of 5nm or even below 3nm. However, EUV lithography technology is also very complex and expensive. Currently, only ASML in the Netherlands can mass-produce EUV lithography machines, primarily supplying them to a few chip manufacturers such as TSMC, Samsung, and Intel. China still lags far behind in EUV lithography technology but is working hard to catch up.
Achievements and Progress
China has achieved the following accomplishments and advancements in photolithography technology:
The Shanghai Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, has proposed a new fast optical proximity effect correction technique, which is based on virtual edges and dual-sampling-rate pixelated mask patterns. This technique can improve the imaging quality of silicon films by lithography machines and reduce the difficulty of chip manufacturing processes. The feasibility of this concept has been demonstrated through simulation experiments.
Shanghai Microelectronics has developed and put into production a 28-nanometer lithography machine, filling the gap in China's non-advanced process technology and is expected to upgrade chip manufacturing processes to 22 nanometers, 16 nanometers, and 14 nanometers.
AMEC has developed and put into production a 3-nanometer etching machine, achieving the first domestically developed extreme ultraviolet (EUV) etching equipment.
Nanjing University Optoelectronics has successfully developed a series of photoresist products such as ArF and KrF, and has achieved large-scale production.
The Harbin Institute of Technology and Tsinghua University teams developed a prototype EUV exposure system and, with the assistance of the Changchun Institute of Optics, Fine Mechanics and Physics and the Shanghai Institute of Optics, Fine Mechanics and Physics, conducted research on key components such as a 13.5-nanometer light source and optical lenses.
Beijing Huazhuo Precision Technology Co., Ltd. has successfully developed a prototype of a dual-stage EUV mask inspection system, which has passed national-level appraisal.
Difficulties and challenges
Although China has made some progress in EUV lithography technology, it still faces many difficulties and challenges. These mainly include the following aspects:
Light source: EUV lithography machines require an extreme ultraviolet light source with a wavelength of 13.5nm, which is a very difficult light source to generate and control. Currently, there are two main methods used internationally to generate EUV light sources: DPP (discharge-generated plasma) and LPP (laser-generated plasma). The DPP method is relatively simple but has lower power; the LPP method has higher power but is also more complex. Currently, China has achieved 100W power output using the DPP method, but this is still significantly lower than the 250W achieved by ASML using the LPP method.
Optical System: EUV lithography machines require special mirrors to transmit and focus the EUV beam. These mirrors need to have extremely high surface precision, reflectivity, cleanliness, and stability. Currently, China has successfully developed a prototype of a two-mirror EUV projection system, but there is still a significant gap compared to the four-mirror or six-mirror systems used by ASML.
A complete EUV lithography machine, besides including the light source and optical system, also comprises multiple components such as a workpiece stage, mask stage, measurement system, vacuum system, and cooling system. These components require high coordination and integration to form a complete and reliable machine. Currently, China has not yet achieved the research and production of a complete EUV lithography machine. It is reported that SMIC has ordered one EUV lithography machine from ASML and plans to put it into use by the end of 2021 or early 2022. In 2022, the global lithography machine market size was US$23.23 billion, with the three giants ASML, Canon, and Nikon monopolizing the market. Shanghai Microelectronics in mainland China has leading lithography technology, capable of mass-producing 90nm resolution ArF lithography machines, and is also expected to achieve breakthroughs in 28nm resolution lithography machines. A lithography machine mainly consists of three core components: a laser light source, an objective lens system, and a workpiece stage. These components work together to achieve more precise lithography. In terms of laser sources, EUV sources have been identified as laser plasma sources. The first high-energy excimer laser independently developed, designed, and manufactured by China's Keyi Hongyuan has filled a gap in China's excimer laser technology. Regarding objective systems, Carl Zeiss is the sole supplier of lenses, mirrors, illuminators, collectors, and other key optical components to ASML. Dual-stage technology is highly complex, and only ASML in the Netherlands possesses this technology. In the field of photolithography coating and development, Shenyang Xinyuan Microelectronics is the domestic leader. In 2022, the company disclosed that it could achieve complete domestic substitution in photolithography coating and development processes at 28nm and above nodes.
1. In 2022, the global lithography machine market reached $23.23 billion. The three giants, ASML, Canon, and Nikon, had revenues of $16.1 billion, $2 billion, and $1.5 billion respectively, with market shares of 82%, 10%, and 8%. Their shipments were 345, 176, and 30 units respectively, with market shares of 63%, 32%, and 5%. Looking at shipments of the three high-end models—EUV, ArFi, and ArF—ASML maintained its leading position, accounting for 100%, 95%, and 87% of shipments respectively. 2. Shanghai Microelectronics in mainland China leads the domestic lithography machine technology and has already mass-produced 90nm resolution ArF lithography machines. Breakthroughs in 28nm resolution lithography machines are also expected. 3. A lithography machine mainly consists of three core components: a laser source, an objective lens system, and a stage. These components work together to achieve more precise lithography. 4. To achieve more precise lithography, it is necessary to increase resolution, and reducing the wavelength of the light source is an important means to achieve this. EUV light sources have been identified as laser plasma light sources, and currently only two companies are capable of producing them: Cymer in the United States and Gigaphoton in Japan. The first high-energy excimer laser independently developed, designed, and manufactured by China's Keyi Hongyuan fills a gap in China's excimer laser technology. 5. Objective lenses are among the most expensive and complex components in a lithography machine. Carl Zeiss is the sole supplier of lenses, mirrors, illuminators, collectors, and other key optical components for ASML. Although there is still a significant gap compared to companies like Carl Zeiss and Nikon, lenses supplied by Aupu Optics can already achieve 90nm. 6. High-end lithography machines all employ dual stages, which can increase production efficiency by more than three times.
Dual-stage technology is highly complex and requires extremely high precision; only ASML in the Netherlands has mastered this technology. Tsinghua University and Huazhuo Precision Technology have collaborated to develop a dual-stage lithography machine with a precision of 10nm. While not as advanced as ASML, this fills a domestic gap. 7. Coating and developing equipment is used in conjunction with the lithography machine for coating, baking, and developing photoresist. Shenyang Xinyuan Microelectronics is the leading domestic player in this field. In 2022, the company disclosed that it could achieve complete domestic substitution in photoresist coating and developing processes for 28nm and above nodes. 8. my country's reliance on foreign semiconductor photoresists exceeds 80%. The self-sufficiency rate for g/i-line photoresists suitable for 6-inch wafers is 20%, for KrF photoresists suitable for 8-inch wafers it is less than 5%, and for ArF photoresists suitable for 12-inch wafers, it is currently almost entirely imported. Lithography technology is a process that uses photoresist to transfer patterns from a photomask onto a substrate. The photolithography process includes core steps such as photoresist coating, exposure, and development. The photolithography machine is the most crucial piece of equipment in this process. The photolithography master is a vital step in creating the photomask. The photolithography machine has a complex structure with more than ten core components. The global photolithography machine market is worth $23.23 billion, dominated by three giants: ASML, Canon, and Nikon. Mainland China accounts for 14% of ASML's sales, and Shanghai Microelectronics' photolithography technology is leading in China.
The laser source, objective lens system, and stage are the core components of a lithography machine; the smaller the numerical value, the stronger the chip performance. 1. Photolithography is a technology that transfers patterns from a photomask onto a substrate using photoresist under the illumination of specific wavelengths of light. The process begins with the light source passing through the photomask, which is then reduced in size by a lens, ultimately allowing the light to fall onto the substrate covered with photoresist. During this process, the photoresist layer in the area covered by the photomask does not harden and is peeled off during etching, thus completing the etching of the substrate. 2. The general flow of the lithography process includes core processes such as coating, exposure, and development, involving a coating machine, a lithography machine, and a developing machine, respectively. Among these, the lithography machine is the most important piece of equipment in the lithography process due to its high technological barriers and high unit cost.
Preparing a reticle is one step in the process. A reticle is a copy of a layered circuit design created on a thin chromium-plated layer of glass or quartz. A reticle can be used directly for photolithography or to create a photomask. A photomask is a glass substrate plated with chromium. After processing, numerous copies of circuit patterns are covered on the surface of the photomask. The photomask uses the entire wafer surface to form the pattern. 3. Rayleigh criterion CD = k1·A/NA, where the wavelength of the light source and the numerical aperture are the main factors affecting resolution. Chip size is a crucial factor determining chip cost; the smaller the chip, the more chips can be cut from a single wafer, resulting in lower chip cost. The critical chip size (i.e., the smallest size that a photolithography system can recognize, i.e., optical resolution) is formulated as CD = k1 - A/NA, where CD is the critical chip size, λ is the wavelength of the light source, NA is the numerical aperture of the optical device, defining how much light can be collected, and k1 is a constant factor related to chip manufacturing; ASML considers its physical limit to be k1 = 0.25.
The lithography machine technology roadmap mainly focuses on breakthroughs in the first two aspects: Regarding the light source wavelength, the light source has evolved from the initial g-line to the current extreme ultraviolet (EUV), with the wavelength shortened from 436nm to 13.5nm; chip fabrication under EUV light can reach 3nm, and ASML is currently the only EUV supplier globally, and it is further developing chips with 2nm and even 1.x nm processes. Regarding numerical aperture, the application of immersion technology has greatly reduced the refraction angle, allowing for a further increase in the diameter of the projection lens. 4. Lithography machines have a complex structure, with more than ten core components.
ASML lithography machines consist of an illumination optics module, a photomask module, and a wafer module. Lithography machine technology is complex, often requiring thousands of suppliers to produce a single machine. Key components include dual stages, a light source system, an exposure system, an immersion system, an objective lens system, and a grating system. Supporting facilities include photoresist, photomasks, and coating/developing equipment. In 2022, the global lithography machine market size was $23.23 billion, dominated by three giants: ASML, Canon, and Nikon. According to SEMI forecasts, lithography machines accounted for 23% of the semiconductor equipment market in 2022, with a market size of $23.23 billion. Specifically, the revenue of the three global lithography machine giants, ASML, Canon, and Nikon, was $16.1 billion, $2 billion, and $1.5 billion respectively, with market shares of 82%, 10%, and 8%; their shipments were 345, 176, and 30 units respectively, with market shares of 63%, 32%, and 5%. Looking at shipments of the three high-end models, EUV, ArFi, and ArF, ASML maintains its leading position, accounting for 100%, 95%, and 87% of shipments respectively.
