ASML is the world’s only maker of EUV lithography, the machines needed to build the most powerful AI accelerators. The company brought the simpler Low-NA version to market in 2019 and has since worked with customers to roll out the more complex High-NA systems.

Bigger photomasks aim to boost throughput by 40 percent

The deal hinges on a small but critical shift in technology. The four companies plan to move their photomasks from today’s six-inch standard to twelve inches. A photomask is a kind of stencil that holds a chip’s circuit pattern. In lithography, light passes through this mask onto a silicon wafer coated with light-sensitive material, transferring the pattern onto the wafer, where transistors and circuit paths are then formed.

The bigger the mask, the more area you can image in a single exposure. Because the six-inch limit capped the size of a single chip, manufacturers had to stack chips vertically and connect them in complex ways, which drove up cost and complexity.

The switch has long been seen as complicated and expensive. But the coordinated push could raise the throughput of High-NA machines by 40 percent and simplify the design process, according to ASML technology chief Marco Pieters, who called it a huge opportunity. TSMC and ASML plan to build a test line for twelve-inch masks by 2031, with production use on High-NA tools set for 2033.

TSMC had been cautious until now, arguing that the productivity gains didn’t yet justify the higher costs. Now the company is reversing course. That matters for ASML, since TSMC accounts for about 16 percent of its revenue. Together with Samsung and Intel, the three biggest customers are on board. Samsung is one of the largest memory makers and plans to use High NA for memory chips starting in 2028, chips whose prices are climbing sharply right now because of demand from AI data centers.

Huawei orchestrates China’s answer to ASML dependence

Meanwhile, Huawei is pushing to strip foreign technology out of China’s semiconductor supply chain and work around Western export controls that cover ASML’s valuable technology, according to a report from the Financial Times. The company is investing across the entire lithography chain and helping broker deals with leading fabs like SMIC.

China isn’t focused on the most advanced EUV technology, but on DUV. The abbreviation stands for Deep Ultraviolet, with a wavelength of 193 nanometers, while EUV works at a much shorter 13.5 nanometers. The shorter wavelength allows finer structures and therefore the most advanced chips. DUV is the older, more mature technology and is used for most chips made worldwide. With so-called multi-patterning, where a pattern is built up over several exposure steps, it can also produce more advanced semiconductors, though at greater effort and cost than EUV.

At the center of Huawei’s effort is Yuliangsheng, a Shanghai equipment maker that helped develop China’s first advanced DUV machine, according to the FT. The company was spun out of SiCarrier, which the FT says has close ties to Huawei, a claim Huawei denies. The machine is being tested by SMIC and on Huawei’s own production lines, so far for less complex semiconductors. Yuliangsheng aims to produce twelve DUV machines by the end of the year, but remains far behind ASML.

Bernstein analyst Lin Qingyuan said Huawei plays a project management role in China’s DUV push, and that a DUV prototype alone isn’t enough. You need thousands of suppliers and customers working together, plus a central orchestrating force.

The biggest bottlenecks remain projection lenses and light sources. Yuliangsheng uses lenses from Zeiss, according to the FT. The company said it sells its optics only to ASML. But insiders point to the secondary market. Huawei’s venture capital arm Habo is at the same time backing Zeiss rivals like Fujian Zhiqi Photonics and light-source developer Beijing RSLaser to become more independent here too.