An employee looks at the coated mirror of High-NA-EUV technology in the clean room of ZEISS Semiconductor Manufacturing Technology

SMT Magazine

High-NA-EUV lithography: mirroring the future

25 January 2024 5 min read

According to current planning, the microchips of the future will be produced with High-NA-EUV lithography from 2025 onwards. Dr. Peter Kürz explains the technology, its importance for our economy and society, and puts it in context of the history of semiconductor development.

An associate works in the clean room on the High-NA-EUV technology

New technology leadership

Microchips are the engines of progress. Their computing power and energy efficiency are driving the digitalization of our economy and society. The roadmap for this progress is being written by ZEISS and its partners. Because the production of both current and future microchip generations requires technologies and innovations for the semiconductor industry: technologies and innovations from ZEISS. Our optical systems for EUV lithography are precise enough to expose billions of transistors onto a silicon surface the size of a fingernail – and with the new High-NA-EUV technology generation, even more will be added! This gives us a lead of several years over our competitors in the market. We are working at full speed to further increase our technology leadership. Our drive is clearly defined: we are paving the way for the microchips of tomorrow, for future IT systems that are even more powerful and energy-efficient. Such as medical systems that support doctors in life-saving operations, in cancer detection and also in eye measurement. In the energy sector, semiconductors produced with ZEISS technologies will make power generation and distribution more sustainable – and in production they will support people during strenuous work. Autonomous driving and AI applications cannot be realized without powerful microchips.

To the website of High-NA-EUV lithography

The product image of the projection optic as a component of High-NA-EUV technology

Small structures, great optics

The process for producing the next generation of microchips is called High-NA-EUV lithography. Based on this technology, semiconductor structures are exposed on a photomask with a light source. Mirrors from the ZEISS Semiconductor Manufacturing Technology (SMT) segment capture the light reflected from the mask and bundle it for projection onto a silicon layer called "wafer". The shorter the wavelength of the light used, the more transistors fit on a microchip. The order of magnitude is now only a few nanometers. For this, ultraviolet light (EUV light) with a wavelength of 13.5 nanometers is used.

ASML's machine for manufacturing state-of-the-art microchips with two employees at the control panel

The finer the structures, the larger the overall system

Right now, the first High-NA-EUV systems from our strategic partner ASML are scheduled to start series production in 2025. "High-NA" stands for high numerical aperture. This measurand describes the angular range from which an optical system can pick up light. The larger the angle, the finer the details that are displayed. With a numerical aperture of 0.55, High-NA-EUV lithography clearly exceeds the current EUV lithography's NA of 0.33. This also means new superlatives for the overall system: the projection optics consists of over 40,000 parts and weighs approximately twelve tons. The same applies for the illumination system. With High-NA-EUV lithography, it weighs more than six tons and consists of more than 25,000 parts. This makes the optics for High-NA-EUV lithography about seven times larger in volume and weight than EUV optics that are currently in use.

Two employees work on a mirror of the High-NA-EUV technology in the clean room

Subatomic precision

The mirrors used for High-NA-EUV technology weigh several hundred kilograms – making them about twice as large and ten times as heavy as previous EUV mirrors. The new generation of mirrors is machined for months in SMT production until it has the required precision. If they were enlarged to the dimension of Germany, the deviation would be only a tenth of a millimeter. This makes them the most precise mirrors in the world.
Corresponding measurement systems operating in the subatomic range did not previously exist for such mirrors. That is why we have completely redeveloped all of the measurement technology together with our strategic partner ASML. Above all, this includes the most complex machine that ZEISS has ever built: a five-by-ten-meter vacuum chamber consisting of more than a hundred thousand parts and a total weight of more than 150 tons. But only here, in a vacuum and absolutely vibration-free space, our mirror surfaces can be measured precisely enough in the sub-nanometer range.

The measuring system for the surface inspection of the mirrors for High-NA-EUV lithography operates in a vacuum chamber measuring five by ten meters. The entire system weighs approximately 150 tons. Broadly speaking, that's 150 tons of know-how.

Dr. Peter Kürz
Head of Field of Business High-NA-EUV lithography at ZEISS

Two employees stand in front of the gigantic metrology for the production of the mirrors for the High-NA-EUV lithography

The future is teamwork

Around 1,500 of the more than 7,500 employees at ZEISS SMT are currently working on the development and realization of High-NA-EUV lithography. More than 25 years of development and research, billions of euros of investment by ZEISS and ASML, and funding from the Federal Government of Germany and the European Union have gone into this technology of the future. Around 2,000 ZEISS patents prove and secure our technological leadership.
Together with our partners, we are empowering chip manufacturers so that the first microchips with High-NA-EUV lithography can roll off the production line in 2025. Our network includes around 1,200 national and international companies. Together, we are driving Moore's Law forward. Postulated as early as 1965, this law states that the complexity of integrated circuits doubles approximately every two years. High-NA-EUV lithography is paving the way to continue Moore's law and thus the digitalization of our economy and society beyond 2030. For the key technologies of the future – and for applications that we cannot even imagine today.