China reportedly caught reverse-engineering ASML’s DUV lithography

A Chinese firm reportedly has sought technical support from ASML, the world’s largest chipmaking equipment supplier, after it failed to reassemble a deep-ultraviolet (DUV) lithography machine following an internal teardown for alleged reverse engineering.

“An ASML DUV machine that China has used to make their chips recently broke down. They called the Dutch company for help repairing it,” Brandon Weichert, a senior national security editor at The National Interest, says in a X post. “ASML sent some techs. They discovered that the Chinese broke the machine when they disassembled it and tried to put it back together.”

“The reason Chinese technicians took apart their older ASML DUV system is simple. They are trying to find a way around US sanctions on the newest machines,” Weichert says. “By taking apart the older model and attempting to rebuild it, they hope to learn how to produce their own advanced versions. But it seems they still can’t figure it out.”

Weichert says he was unsure whether ASML had repaired the system. He adds that, in his view, although China maintains service agreements with the Dutch company, ASML would be unlikely to honor them given what he characterized as apparent foul play by the customer.

Weichert’s post, released on October 19, came at a sensitive moment in US-China relations. Political tensions between Washington and Beijing had heightened as the US refused to ease its export restrictions on advanced chipmaking technology, while China responded by tightening export controls on rare earth elements.

US President Donald Trump, who threatened to impose an extra 100% tariff on Chinese goods, will meet Chinese President Xi Jinping during the APEC Summit in South Korea on October 30, where discussions are likely to cover bilateral trade, fentanyl flows, semiconductor policy, rare earth exports, and other pressing geopolitical issues. 

As of now, there is no other source that can verify Weichert’s claims. However, many Chinese columnists have admitted that reverse engineering is the only realistic path for China to replicate ASML’s lithography machines.

“Western nations, led by the US, have long sought to restrict China’s access to advanced semiconductor technology by preventing the purchase of leading lithography systems,” says a Jiangxi-based columnist writing under the pseudonym “Spacewave Receiver.” 

“The challenges of independently producing lithography machines are immense, but China has already achieved some technological breakthroughs with its vast market, strong capital resources and growing research capability,” he says. “Through reverse engineering, Chinese researchers are gradually mastering key components and laying the groundwork for the domestic chip industry’s rise.”

He cites the example of Zhao Yongpeng, a professor at the Harbin Institute of Technology’s School of Astronautics, who successfully developed a discharge plasma extreme ultraviolet (EUV) light source in 2024. He stresses that China is now on the verge of breaking the foreign technology blockade and that its chip manufacturing sector will continue to expand. 

Challenges of reverse engineering

Some Chinese commentators have noted that reverse-engineering ASML’s immersion DUV lithography machines is an exceptionally complex challenge.

A Guangdong-based columnist writing under the pen name “Chengwa” highlighted four key difficulties: 

• Extreme precision: DUV systems use 193-nm argon fluoride (ArF) lasers and a thin water layer beneath the lens. Even the tiniest misalignment can cause a chain reaction of system errors.
• Complex mechanics: Inside modern DUV immersion tools, twin wafer stages move rapidly under the lens with sub-nanometer accuracy and process around 330 wafers per hour. Removing one stage without factory calibration can destroy the delicate alignment that field engineers cannot easily restore.
• Highly integrated technology: ASML’s equipment depends on intricate optical systems, motion platforms and control software perfected in Europe over decades. Replicating all these technologies from scratch is extraordinarily difficult.
• Precision calibration: The system’s accuracy depends on closed-loop calibration linking optics, sensors and motion control. Dismantling the tool can lead to particle contamination, interferometer drift and loss of key reference points. These problems require vendor-level software keys and procedures to correct.

Currently, the three major Chinese lithography firms are Shanghai Yuliangsheng Technology, Shenzhen SiCarrier Technologies and Shanghai Microelectronics Equipment (SMEE). SiCarrier works closely with Huawei Technologies and has a stake in Yuliangsheng.

Song Yihong, a Henan-based columnist, says China’s domestic lithography supply chain is expanding, with several emerging players across lenses, lasers, and precision components.

• Lens manufacturers: Nanjing Wavelength Opto-Electronic, Ningbo Yongxin Optics, MLoptic and Changchun UP Optotech are among the key firms producing or supporting optical systems for China’s leading lithography makers.
• Laser and process technology: Inno Laser Technology and Keystone Technology are developing advanced laser sources and patterning processes.
• Precision components: Chongqing Millison Technologies supplies robotic bases and vacuum chambers for domestic lithography tools.

China’s lithography push

For many years, China has relied heavily on ASML’s lithography machines for advanced chip manufacturing. Shanghai Microelectronics Equipment Co Ltd’s SSX600 series, SMEE’s most advanced model to date, is officially capable of producing 90-nanometer (nm) chips.

After the US banned sales of ASML’s extreme ultraviolet (EUV) lithography machines to China in 2019, Beijing began pouring substantial investment into homegrown lithography development. However, much of that funding has been marred by inefficiency and corruption scandals, limiting technological progress.

In September 2024, the Ministry of Industry and Information Technology (MIIT) announced that two domestically made lithography systems had been added to its recommended list for adoption by Chinese semiconductor manufacturers. One system was capable of producing 130 nm chips, while the other was designed for 65 nm chips.

Last month, the Financial Times reported that China’s leading chipmaker, Semiconductor Manufacturing International Corporation (SMIC), was testing a DUV immersion lithography machine made by Yuliangsheng.

The machine is understood to be an immersion DUV scanner targeting 28-nm chip production, roughly matching the performance of ASML’s Twinscan designs in 2008. Yuliangsheng planned to deploy it on production lines by 2027. 

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Follow Jeff Pao on Twitter at @jeffpao3