Zeiss SMT expands German site that caps ASML EUV scanner output

The only two facilities in the world capable of manufacturing the optical columns inside ASML's lithography scanners are undergoing major expansion, the company announced Friday.

Expansion at Oberkochen and Wetzlar

Carl Zeiss Semiconductor Manufacturing Technology (SMT) confirmed it is adding approximately 25,000 square meters of production and production-adjacent space at its Oberkochen site in southern Germany. Staff began moving into the first completed building this month, four years after the groundbreaking in 2022. The remaining buildings will be handed over in stages.

Oberkochen and Wetzlar are the only two locations globally where the optical columns can be built. ASML's own annual report states that the number of systems it can produce is limited by Zeiss SMT's production capacity.

Production Targets and Capacity Increases

ASML told investors earlier this month that it plans to increase Low-NA EUV output by roughly 30% in 2027.

CFO Roger Dassen said during ASML's July earnings call that the company is:

• Nearly fully booked on Low-NA EUV for 2027
• Raising capacity by approximately 30% from roughly 65 systems this year
• Evaluating another 30% increase for 2028

Dassen also told reporters that ASML is compressing its scanner build cycle from around 22 weeks to 15 or 16 weeks. It is understood that ASML is planning price hikes for Low-NA EUV machines, a move that has reportedly upset TSMC.

Critical Supplier Relationship

ASML's 2025 annual report describes Carl Zeiss SMT as its sole supplier of lenses, mirrors, illuminators, collectors, and other critical optical components, held under an exclusive arrangement. The filing warns that if Zeiss could not sustain production over a prolonged period, ASML "would effectively cease to be able to conduct our business."

Purchases from Zeiss SMT and its subsidiaries reached:

• 2025: €4.41 billion
• 2024: €3.95 billion
• 2023: €3.33 billion

(1 Euro = 1.14 USD)

High-NA EUV Optics Complexity

High-NA projection optics contain more than 40,000 parts and weigh approximately 12 tons — roughly seven times the volume and weight of standard EUV optics. The illumination system adds another 25,000 parts and 6 tons.

Individual High-NA mirrors weigh several hundred kilograms, around twice the size and 10 times the weight of current EUV mirrors. Zeiss says they are machined for months before reaching the required figure. Verification requires a purpose-built vacuum chamber measuring 5 by 10 meters, made up of over 100,000 parts and weighing more than 150 tons.

Intel became the first company to ship high-volume logic on 0.55 NA scanners this month. Adding floor space does not shorten any of those steps.

Financial Support and Loan Arrangements

ASML held:

• €1.91 billion in loans receivable from Zeiss SMT at the end of 2025 (up from €1.44 billion a year earlier)
• €1.19 billion in advance payments made to secure optical column deliveries

Two €1 billion facilities are in place, signed in September 2021 and September 2024. ASML issued a further:

• €444 million loan in July 2025
• €212.5 million short-term loan in November 2025

A May 2025 restatement of the company's framework agreement made the capex loans interest-free, with repayment expected over seven or 15 years and quarterly installments that vary with Zeiss SMT's revenue.

Zeiss SMT Performance and Other Developments

Zeiss SMT booked €5.055 billion in the fiscal year ending September 30, 2025, up 23% and the largest of the Zeiss Group's four segments.

Additional developments include:

• Building a multifunction factory at Wetzlar
• Adding 300 square meters of cleanroom at Rossdorf last fall
• Opening an innovation center in Korea this month