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 very 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: . That's an unusually concentrated customer base for any business, but it makes sense given what Zeiss builds: mirrors and lenses precise enough to focus extreme ultraviolet light without losing the pattern being printed, a capability no other company has matched. ASML's relationship with Zeiss goes beyond a supply contract; ASML owns close to 24.9% of the company, tying the two together as both customer and part-owner.