While concerns persist regarding China potentially reverse-engineering ASML's extreme ultraviolet (EUV) lithography machines, experts highlight significant barriers to successful replication.

In June, the U.S. Department of Commerce informed Dutch firm ASML of suspicions that one of its extreme ultraviolet lithography machines had reached China. ASML denied the claim, and no public evidence has been provided. As the sole global producer of these advanced chip-making machines, ASML remains a central figure in the technological competition between the United States and China.

Complexity of EUV Systems

EUV machines are among the world's most complex products, containing over 100,000 components at the system level and roughly 700,000 when counting parts within subsystems. These machines must operate within tolerances smaller than atoms, requiring precise synchronization to avoid performance degradation from heat, vibration, or contamination. ASML achieves this through decades of accumulated experience, supplier collaboration, and iterative testing.

Limits of Reverse Engineering

Experts suggest that physical access to an EUV machine, blueprints, or the hiring of former engineers is unlikely to allow China to replicate the technology in a policy-relevant timeframe. Much of the necessary knowledge is tacit, distributed across thousands of global suppliers and engineers, and not fully documented. Furthermore, China has yet to catch up to older immersion deep ultraviolet machines from the late 2000s.

Supply Chain Dependencies

Even if a prototype were developed, China would face a highly concentrated global supply chain for essential materials and equipment. This includes photoresists, mask blanks, and specialized coaters and developers. For example, Tokyo Electron holds nearly 100 percent of the market for EUV photoresist coaters and developers, and qualified resists are primarily supplied by a small group of Japanese-headquartered companies.