Why Former U.S. Officials Want a Ban on ASML’s DUV Tools and Servicing in China

Former U.S. officials are calling for a complete ban on sales and servicing of immersion deep ultraviolet (DUV) lithography equipment in China because they say limits on new exports leave a consequential gap: Chinese chipmakers can keep adding machines, and installed tools still need support. Their proposal would close both routes. The urgency they attach to it is based partly on an estimate that Chinese-owned fabs had acquired 343 immersion DUV systems by early 2026, worth billions of dollars. That figure is an estimate, not a publicly verified inventory.3

Why immersion DUV tools matter

Extreme ultraviolet (EUV) lithography is used for the most advanced chipmaking, and China has not had access to EUV systems. But that does not mean it cannot produce some advanced chips. DUV equipment, combined with repeated patterning steps, can be used to make 7-nanometre-class logic chips. A report on the technology describes Chinese chipmakers using DUV tools to produce chips at that class of node without EUV.15

The officials’ concern is that a large installed base of immersion DUV tools could support more advanced chip production, including chips relevant to AI. The stockpile estimate is therefore central to their argument: stopping additional purchases alone might not quickly constrain production if existing equipment can continue operating.315

What a complete ban would add

Dutch export controls already require licences for certain advanced lithography machines. The proposed approach would be broader: restrict sales of immersion DUV equipment across China and prevent servicing of machines already in use. That would extend beyond blocking particular shipments or restricting access at individually designated companies.4

Servicing matters because a sales ban only affects future deliveries. A report on China’s two leading memory chipmakers says their stockpiled equipment could support three years of planned capacity expansion. That report concerns those firms’ plans; it does not establish how long every Chinese fab could operate without new tools or service.19

What the MATCH Act could—and could not—do

The proposed MATCH Act is a separate legislative route for expanding restrictions and aligning U.S. rules with those of allies, including the Netherlands and Japan. A scaled-back version still included a countrywide restriction on ASML immersion DUV machines, according to Reuters. The bill is proposed legislation, not an enacted blanket ban.12

If allies declined to align their controls, reporting on the proposal says Washington could seek to use U.S. export-control rules—including an expanded Foreign Direct Product Rule—to reach equipment containing U.S. technology. That is a proposed enforcement mechanism, not proof that the United States could automatically impose a comprehensive servicing ban on a Dutch supplier without Dutch cooperation.9

The trade-offs and uncertainties

A ban could affect ASML’s China business, but the available sales figures do not show how a servicing restriction would affect the company or Chinese chip output. China accounted for a reported 19% of ASML’s net system sales in the first quarter of 2026 and 14% in the second quarter.58

China is also pursuing domestic immersion lithography tools. The available reporting describes progress but leaves the pace and competitiveness of domestic alternatives uncertain.18 That uncertainty cuts both ways: domestic tools could eventually reduce the effect of restrictions, while a near-term ban could still constrain access to imported equipment and support.

The core case for the proposal is straightforward: if the estimated stockpile is large and servicing helps keep it useful, restricting sales alone may leave a substantial supply of tools in operation. But the estimate is not a confirmed inventory, the MATCH Act is not law, and neither domestic substitution nor the sales figures establish how quickly a complete ban would change China’s chipmaking capacity.