EUV

Computer chips are made by exposing tiny patterns onto round silicon discs – similar to photography, only millions of times smaller. The shorter the light wave used for exposure, the finer these patterns can be. EUV is the abbreviation for extreme ultraviolet light, radiation that is invisible to the human eye. Its wavelength is 13.5 nanometers, roughly one forty-thousandth of the thickness of a hair. It took about twenty years of research before this light became industrially usable. Today, chips exposed with EUV are found in almost every new smartphone.

The bottleneck of the entire chip industry

Without EUV, today’s fastest processors would not exist. Previously, exposure was done with light at a wavelength of 193 nanometers, i.e. with significantly coarser waves. To still produce fine structures with it, the same disc had to be exposed multiple times in succession. This cost time, created scrap, and eventually hit a limit. EUV accomplishes in a single pass what previously required four steps.

The market situation is particularly explosive. Worldwide, only a single company builds EUV machines: the Dutch corporation ASML. One machine costs between 150 and 400 million euros and is delivered in several cargo planes. Whoever doesn’t get one cannot manufacture the most advanced chips. This has turned a technical question into a political one.

The European Union and the United States have heavily restricted the export of these machines to China. Chinese manufacturers therefore currently cannot keep up at the most advanced production stages. When business news talks about a chip war, it very often concerns precisely these machines.

How light is generated from tin droplets

EUV light cannot simply be produced with a lamp. Inside the machine, about 50,000 tiny droplets of liquid tin fall through a chamber every second. Each droplet is hit twice by a laser: the first shot flattens it into a disc, the second vaporizes it. This creates an extremely hot plasma, i.e. a gas of charged particles, which emits EUV radiation.

A second problem is guiding the light. EUV is absorbed by every material, including glass and even air. Normal lenses therefore don’t work. Instead, the machine uses mirrors made up of around a hundred ultra-thin layers. These mirrors are the smoothest objects ever manufactured by humans. The entire beam path lies in a vacuum, since otherwise nothing would arrive.

In the end, only a fraction of the energy used remains. A machine consumes about as much electricity as several hundred households. Nevertheless, it pays off, because well over a hundred silicon discs are exposed per hour. Each of these carries hundreds of chips.

Where EUV shows up in products and headlines

You will never directly see an EUV machine. But you use its results every day. The processors in current iPhones, modern laptop chips, and the graphics processors on which AI models are trained are all produced using EUV exposure. They can only be manufactured in a few factories, mainly in Taiwan, South Korea, and increasingly in the United States.

In financial news, the term is often encountered in connection with nanometer figures such as 3 nm or 2 nm. Today, these numbers are more marketing names for production stages than actual measurements. Another common misconception is that EUV itself is a chip or a technology within the chip. In fact, it is merely the tool used for manufacturing.

The industry is currently discussing the next expansion stage, called High-NA EUV. It uses larger mirrors and thereby images even finer structures. The first devices have been in place at Intel and other manufacturers since 2024. Anyone reading reports on ASML’s delivery figures learns fairly precisely how the entire semiconductor industry is doing.