EUV Lithography: A European Joint Project

Lithography based on extreme ultraviolet light enables ever finer structures to be created on computer chips. As a result, these continuously achieve a higher transistor density and become more powerful and energy efficient. Together with its strategic partners ASML and TRUMPF, ZEISS is the global market leader in EUV technology – thanks to around 25 years of research and development by several thousand employees.

The heart of progress beats in a microchip. The new mobile phone and the next video conference, Industry 4.0 and 5G networks, autonomous driving and, last but not least, innovative medical technology – all are based on increasingly more powerful microchips. As a key technology, microelectronics and nanoelectronics thus form the basis for technological progress in important European application industries. German and European policy supports the industry in order to secure access to these strategically important goods for Europe. In addition, innovations are to be driven forward by research, development and manufacturing in Europe. The German government has been promoting EUV technology since the late 1990s.

European funding has also flowed in as part of so-called "Joint Undertakings." This is the case with "Important Projects of Common European Interest (IPCEI)", for which five European countries have joined forces. They support high-risk but highly innovative projects of small and large companies in the capital-intensive semiconductor industry. In Germany, ZEISS realized the world's most advanced fab for EUV lithography optics with the help of the project. This enabled ZEISS to expand its international leading position in this technology and create more than a thousand jobs.

Today, the smartphone in your pocket is more powerful than all the computers NASA used to take men to the moon and back fifty years ago. In this era, Gordon Moore postulated the law named after him: The co-founder of Intel predicted that the number of transistors on a computer chip would double every two years. At the time of the moon flights, an average microchip had just 1,000 transistors; today there are more than fifteen billion. Moore was right – because dedicated teams around the globe have worked and are working continuously to develop computing power even further.

A key technology for this is optical lithography. With this process, the structures of a photomask are imaged by light onto the light-sensitive layer of a silicon wafer, as in a slide projector. The shorter the wavelength of the light, the finer the patterns on the wafer, which is later used to create microchips. This increases the number of transistors on the same area as well as the possible computing power.

EUV stands for extreme ultraviolet light. With a wavelength of just 13.5 nanometers, structures can be created that are a tiny 15 nanometers in size – 5,000 times finer than a human hair. The microchips produced with this technology are not only more compact and more powerful overall – they also consume around 30 percent less energy than the latest generation of chips, which is produced with a longer wavelength of 193 nanometers. However, the challenges for EUV lithography are enormous: because air and glass absorb EUV light, the exposure needs to occur in a vacuum – and only high-precision mirrors may be used instead of optical lenses. EUV mirrors from ZEISS are the most accurate mirrors in the world today. Scaled up to the size of Germany, the largest unevenness would be just a tenth of a millimeter. The sensors and actuators in a ZEISS projection optics work so precisely that a reflected laser beam could hit a golf ball on the moon with pinpoint accuracy. ZEISS has secured this technology with more than 2,000 patents.