Chinese fabs are quietly extending the useful life and performance of older ASML deep ultraviolet lithography systems by upgrading key subsystems, as Beijing pushes to sustain advanced chip output under tightening U.S. and allied export controls, according to the Financial Times. The effort concerns installed immersion DUV tools, particularly ASML’s Twinscan NXT series. It’s understood that these activities have been underway over the past year at several leading-edge Chinese fabs, including those operated by SMIC and other state-backed manufacturers.
With access to EUV scanners cut off and new restrictions narrowing what ASML can legally service or upgrade, Chinese firms are increasingly turning to reverse engineering and grey-market components to improve overlay accuracy, stability, and throughput on tools originally designed for older process nodes. While this upgrade activity will never bring older DUV machines to parity with newer EUV machines, it could provide Chinese manufacturers with a meaningful recovery of capacity at advanced DUV-based nodes that remain commercially viable.
A growing ecosystem
(Image credit: ASML)
Export controls imposed by the U.S. and its allies were primarily designed to prevent the export of cutting-edge technologies to China. For lithography, that meant blocking EUV outright and, more recently, placing tighter licensing requirements on the most capable immersion DUV scanners.
While these measures have worked as intended at the point of sale, they haven’t eliminated the installed base of immersion scanners already operating inside China. Over the past decade, Chinese fabs acquired dozens of high-end DUV tools, which now form the backbone of China’s most advanced production lines, particularly for 14 nm, 10 nm, and experimental 7 nm-class processes that rely heavily on multipatterning. Despite tens of billions in capital expenditure on chipmaking tools, China remains more than a decade behind current market leaders.
Under current rules, ASML is allowed to provide basic maintenance and support to keep these tools running, but it is restricted from performing upgrades that would materially improve performance beyond narrow thresholds. That has created a gap between what the original equipment manufacturer can legally do and what fabs are technically capable of doing with the right parts and expertise.
Into that gap has stepped a growing ecosystem of third-party suppliers and engineers. According to the report, Chinese fabs have sourced replacement or upgraded components such as wafer stages, optical elements, sensors, and control subsystems through secondary markets. Some of these parts originate from dismantled tools outside China, while others are produced by suppliers that operate in regulatory grey zones. Installation and calibration work is carried out by independent engineers, including former lithography specialists, rather than by ASML personnel.
This might sound inconsequential on the face of it, but with an outright ban on exports of new tooling, marginal improvements to existing tools compound quickly across high-volume lines. A small improvement in overlay stability can translate into higher yields across dozens of layers.
Overcoming overlay challenges
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