What Does Carl Zeiss SMT Make? The Optics Inside Every EUV Machine

Every EUV lithography machine ASML sells contains optics that only one company on earth can build. Here's what Carl Zeiss SMT makes, why ASML partly owns it, and how deep the dependency runs.

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Aug 9, 2026 · 2 min read

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ASML is the only company that builds extreme ultraviolet lithography machines, the tools needed to print the smallest transistors on the world's most advanced chips. Inside every one of those machines sits an optical system that ASML doesn't build itself. Carl Zeiss SMT does, and it's the only company that can.

The short answer

Carl Zeiss SMT sits at the center of advanced chipmaking:

• Who it sells to: ASML is its only customer for lithography optics, and also owns roughly 24.9% of the company.
• Who depends on it indirectly: TSMC, Samsung Electronics, and Intel all run EUV scanners built around Zeiss optics.
• What it's made from: SCHOTT AG supplies the ultra-low-expansion glass-ceramic substrates that Zeiss polishes into mirrors; Corning supplies an alternative ultra-low-expansion glass used for the same purpose.

The full interactive map is on Carl Zeiss SMT's supply chain page.

A single customer, and a stake in it

Carl Zeiss SMT sells its lithography optics to exactly one company: . Few businesses rely on a single customer like that, but it makes sense given what Zeiss builds. Its mirrors and lenses are precise enough to focus extreme ultraviolet light without blurring the pattern being printed, and no other company has matched them. The relationship is more than a supply contract. ASML owns close to 24.9% of Zeiss SMT, so it is both the only customer and a part-owner.

Why the whole chip industry depends on it

TSMC, the world's leading foundry, runs EUV production that depends on the Zeiss optics inside its ASML machines. Samsung Electronics and Intel run the same category of scanners for their own leading-edge nodes. None of these companies buy from Zeiss directly, but every chip made on an EUV line has been printed through Zeiss optics.

What the optics are made from

Building a mirror this precise starts with a substrate stable enough not to distort under heat. SCHOTT AG supplies ZERODUR, an ultra-low-expansion glass-ceramic that gives Zeiss a dimensionally stable blank to polish into an EUV mirror. Corning supplies an alternative material, ULE glass, used for the same category of mirror and photomask blanks. On the equipment side, TRUMPF co-developed the EUV light source itself, supplying the high-power laser that ASML integrates alongside Zeiss's optics inside every EUV scanner.

See it for yourself

The full breakdown, with live tickers for every company involved, is on Carl Zeiss SMT's supply chain map.