ZEISS SMT opens new cleanrooms at Rossdorf site

• The segment ZEISS Semiconductor Manufacturing Technology (SMT) has expanded its research and development site in Rossdorf
• 300 square meters of cleanroom space have been added.
• Hesse’s Prime Minister Boris Rhein: "A strong signal for our economic location“.

The ZEISS segment Semiconductor Manufacturing Technology (SMT) has put into operation an additional 300 square meters of cleanroom space at its research and development site in Rossdorf, southern Hesse – an increase in area of 80 percent. This strengthens the company's position in a highly specialized area of semiconductor production: the development of high-precision mask repair systems. The measure is part of a larger investment package with a total volume of more than 20 million euros. "The semiconductor industry is of central importance for nearly all future technologies – from autonomous driving to artificial intelligence. That a company like ZEISS is investing in Hesse is a strong signal for our economic location," says Hesse's Prime Minister Boris Rhein. He attended a small opening ceremony on September 17, 2025, in Rossdorf and also took the opportunity to tour the site. Around 280 employees of the strategic business unit ZEISS Semiconductor Mask Solutions (SMS) are employed in Rossdorf.

With the new cleanrooms, ZEISS SMT not only creates optimal conditions for precision work in the nanometer range – clean, vibration-free, and controlled – but also urgently needed space: the expansion provides room for four additional tools, highly specialized systems that enable the production of defect-free high-end photomasks. "The commissioning is a milestone for our business," says Dr. Clemens Neuenhahn, Head of ZEISS SMS. "We are specifically expanding our research and development capacities to meet the increasing technological complexity in mask repair. ZEISS traditionally invests in research and infrastructure – this is a central prerequisite to remain a technology leader in the future." Rossdorf has been a site of ZEISS SMT since 2005 – at that time, ZEISS acquired NaWoTec GmbH, a spin-off of Deutsche Telekom. "In the past 20 years, our team has grown significantly: in 2015 we were about 80 employees, today around 280. This development shows what is possible with start-up DNA, the backing of a global technology corporation, and the tech ecosystem around Darmstadt," says Dr. Patrick Villwock, development and site manager of ZEISS SMT in Rossdorf.

Rossdorf offers several advantages as a location: its position in the Rhine-Main metropolitan region ensures excellent transport connections – with Frankfurt Airport as an international logistics and travel hub. The proximity to the scientific city of Darmstadt, its Technical University, and research institutions is also a crucial plus. ZEISS maintains intensive networks with students and educators and benefits from the proximity to academic talent. Additionally, there is a research cooperation with the ZEISS Innovation Hub @ KIT in Karlsruhe – an interdisciplinary development center at the interface of science and industry.

Photomasks serve as optical templates in microchip manufacturing, allowing the finest nanostructures to be exposed on silicon wafers – comparable to an extremely precise slide. Even the smallest defects on these masks can lead to scrap and thus impair the quality and cost-effectiveness of production. The MERiT® systems developed at the Rossdorf site by ZEISS SMT correct such errors contactlessly, using electron beam technology and nanometer precision – without damaging the masks. They help ensure yield in production and guarantee the quality of modern microchips. All major semiconductor manufacturers worldwide use the systems from ZEISS SMT to reliably repair photomasks. As microchips continue to get smaller, more powerful, and more energy-efficient, the demands on repair processes are also increasing. Therefore, the technology in Rossdorf is continuously being further developed.