Corning unveils Extreme ULE glass for next-generation high-NA EUV lithography

Corning has just rolled out a new ultra-low expansion (ULE) material geared up to handle the increasing power of the upcoming low-NA and high-NA EUV lithography systems. This shiny new Extreme ULE glass is set to be the go-to for the next-gen photomasks and lithography mirrors in future fab tools.

The key feature of Extreme ULE is its exceptionally low thermal expansion, which provides exceptional consistency for photomask use. Plus, it's really flat, which helps fight that pesky "photomask waviness" and cuts down on unwanted variations in chip production. These features mean we can use advanced pellicles and photoresists to ramp up yields and performance.

EUV lithography systems employ a plasma source to create super intense EUV light, which also cranks out a lot of heat. Most of that heat, though, stays in the source chamber, separate from the photomask. The EUV light then gets aimed at the photomask through fancy lithography mirrors, but those mirrors can be sensitive to heat.

The photomasks are made of multilayer reflective materials designed to bounce back EUV radiation really well. They do a great job of reflecting, but they still soak up a tiny bit of that EUV light, which means the photomask ends up with a bit of extra thermal load.

As EUV tools step up their game and process more wafers per hour (WPH), they bring in some potent light sources. This means pellicles, photomasks, and photoresists face higher levels of EUV radiation and heat. Corning's Extreme ULE glass, which builds on the classic ULE family, delivers incredible thermal stability and uniformity, just what the next-gen high-NA and soon-to-be low-NA EUV tools need.

"As the demands of integrated chipmaking grow with the rise of artificial intelligence, glass innovation is more important than ever," said Claude Echahamian, Vice President & General Manager, Corning Advanced Optics. "Extreme ULE Glass will expand Corning's vital role in the ongoing pursuit of Moore's Law by helping enable higher-powered EUV manufacturing as well as higher yield."