US lawmakers are preparing legislation that would extend semiconductor export controls to deep ultraviolet (DUV) lithography machines — the last significant category of advanced chip manufacturing equipment that can still be legally exported to China. The move, reported by Asia Times, would close what industry analysts have called the “last loophole” in the US semiconductor containment strategy, and would directly affect ASML, the Dutch company that manufactures both the restricted extreme ultraviolet (EUV) machines and the still-exportable DUV systems. If enacted, the legislation would represent the most significant escalation in semiconductor export controls since October 2022.
The DUV Gap: How China Has Been Making 7nm Chips
The US export control regime has focused heavily on EUV lithography — the technology required to manufacture chips at 5nm and below using a single patterning step. ASML’s EUV machines have been restricted from export to China since 2019. But DUV machines, which use shorter-wavelength light and are older technology, have remained exportable, subject to case-by-case review.
Chinese chipmakers, led by SMIC, have exploited this gap through a technique called multi-patterning: using DUV machines multiple times on the same wafer to achieve effective feature sizes that approach those achievable with EUV in a single pass. SMIC demonstrated 7nm production using this technique in 2022 and has continued to refine it. The process is more expensive and lower-yielding than EUV-based production, but it works — and it has allowed China to produce chips for applications including Huawei’s Kirin processors and AI accelerators. The existence of this pathway has been a persistent frustration for US policymakers who believed the 2019 EUV restrictions would effectively cap China’s chip capabilities.
What the Proposed Legislation Would Do
The bill under discussion would add ASML’s NXT series DUV machines, specifically the NXT:2000i and NXT:2050i, which are the most capable DUV systems and the ones most useful for multi-patterning at advanced nodes, to the US Commerce Department’s export control list. It would also extend controls to DUV-related consumables and maintenance services, closing secondary pathways that have allowed Chinese chipmakers to keep existing DUV machines operational.
The legislation would require coordination with the Netherlands and Japan, both of which have their own export control regimes and have been under US pressure to align them more closely with American restrictions. ASML is a Dutch company, and Japan’s Nikon also manufactures DUV systems. Without multilateral alignment, a unilateral US restriction on DUV would be partially circumventable through non-US suppliers. The diplomatic challenge of securing Dutch and Japanese cooperation is likely to be as significant as the legislative challenge of passing the bill.
ASML’s Exposure and Market Reaction
ASML’s stock fell on news of the proposed legislation. EastFrontier has reported on ASML and the MATCH Act before. China accounted for approximately 29% of ASML’s revenue in 2025, with DUV systems making up the majority of that exposure, EUV exports to China have been restricted for years. A DUV export ban would remove a significant revenue stream at a time when ASML is already navigating slower-than-expected EUV adoption in Europe and the US.
The company has previously argued that restricting DUV exports would harm its own competitiveness without meaningfully slowing China’s chip development, since Chinese chipmakers have already stockpiled large numbers of DUV machines. That argument is likely to feature prominently in the lobbying effort against the legislation. ASML’s CEO has consistently maintained that export controls on equipment that China has already acquired in large quantities are more symbolic than effective — a position that US lawmakers have increasingly challenged.
China’s Response: Accelerating Domestic Alternatives
For China, the proposed DUV restrictions are a further incentive to accelerate domestic lithography development. Shanghai Micro Electronics Equipment (SMEE) has been developing domestic DUV systems, though its most advanced machine is currently capable of 28nm production, far behind ASML’s NXT series. The gap is significant, but the direction of travel is clear: every tightening of US export controls accelerates Chinese investment in domestic alternatives. The proposed legislation, if enacted, would signal that the US is prepared to accept the economic costs of a more comprehensive technology decoupling, and would force China to accelerate its own semiconductor self-sufficiency timeline accordingly.
For the semiconductor industry globally, the DUV debate is a preview of a larger question: how far is the US willing to go in restricting technology exports to China, and at what cost to its own companies and allies? ASML’s situation, a European company caught between US policy demands and its own commercial interests, illustrates the difficulty of maintaining a coherent multilateral export control regime when the economic stakes are this high. The outcome of this legislative push will shape the trajectory of the US-China tech war for years to come. If the US succeeds in restricting DUV access, it will have closed the last major gap in its semiconductor containment strategy; if it fails, it will have demonstrated the limits of unilateral technology controls in a world where critical equipment is manufactured outside American borders.