EUV Lithography

A computer chip consists of billions of tiny switches sitting on a thin slice of silicon. These switches are not built individually, but exposed onto the wafer like a photograph. A pattern is projected through light onto a light-sensitive layer, and afterward, whatever was not exposed is etched away. How fine this pattern can be depends on the wavelength of the light: the shorter the wave, the smaller the details. EUV lithography uses light with a wavelength of only 13.5 nanometers, roughly one fifty-thousandth of a millimeter. This makes it possible to create structures that could no longer be made cleanly with older, longer-wavelength light.

A Bottleneck of the Global Economy

There is exactly one manufacturer of such machines worldwide: the Dutch company ASML. No other company and no other country has so far built a working EUV system. A single machine costs, depending on configuration, between 150 and over 350 million euros and is delivered in parts by cargo aircraft.

This results in an unusual power dynamic. Anyone who wants to manufacture modern processors for smartphones or AI data centers cannot avoid EUV. The major chip factories of TSMC in Taiwan, Samsung in South Korea, and Intel in the USA all depend on the same supply chain.

For this reason, the technology has long been a political issue. Under pressure from the USA, the Netherlands prohibits the export of EUV machines to China. China can still manufacture chips, but only with older technology and correspondingly greater effort per chip. ASML figures and new export regulations therefore regularly move stock prices.

How the 13.5-Nanometer Light Is Generated

EUV light cannot be produced with a normal lamp. Inside the machine, a powerful laser fires at tiny droplets of liquid tin, around 50,000 times per second. Each droplet turns into an extremely hot plasma that briefly flashes, emitting the desired radiation. The efficiency is low: only a small fraction of the energy used ends up as usable light on the wafer.

A second problem is the path of the light. EUV is absorbed by air as well as by ordinary glass. Lenses are therefore impossible; the entire optical system works with mirrors, and does so in a vacuum. These mirrors consist of around a hundred ultra-thin layers and rank among the smoothest surfaces humans can produce.

The pattern itself comes from a mask, a kind of stencil at an enlarged scale. The optics shrink the image and project it onto the silicon wafer, which moves at high speed during exposure. A modern chip is created through many such exposure steps, layer upon layer.

EUV in Phones, Graphics Cards, and Stock Market News

You practically never see an EUV machine directly. But almost everyone carries its result in their pocket. The main processor of a current smartphone is exposed using EUV, just like the chips on which large AI models are trained.

In the news, the term usually appears together with nanometer figures, such as “3-nanometer manufacturing.” These numbers, however, are nowadays more of a marketing label for a manufacturing generation than an actual measurement. Another common misconception is that EUV automatically makes chips faster. At first, it merely allows more switches on the same area, which can improve performance and power consumption.

Economically, EUV is a perpetual topic because this technology determines who will be able to build the most powerful chips in the future. The next step is called High-NA EUV and works with larger optics for even finer structures. The first such machines are already in place at Intel and at research centers.