How EUV Lithography Works: Inside the $200M Machine That Prints the Future

Every iPhone, every Nvidia GPU, every AI data center on the planet depends on a machine built by exactly one company. ASML of the Netherlands is the sole manufacturer of extreme ultraviolet lithography systems, the tools that print the circuitry of the world's most advanced chips. Without them, modern computing simply stops advancing.

The machine works by firing lasers at droplets of molten tin 50,000 times per second, creating plasma hotter than the surface of the Sun, then steering the resulting light with mirrors polished to atomic precision. It is arguably the most complex manufactured object in human history. Here is how it works.

Light that nothing can touch

Lithography is printing with light. A chip's circuit pattern is projected onto a silicon wafer coated with a light-sensitive chemical, and the precision of that projection sets how small transistors can be. In the 1960s, engineers used visible light (380 to 780 nanometers). As chips demanded finer features, the industry moved to ever shorter wavelengths: ultraviolet at 365nm, excimer lasers at 248nm, then deep ultraviolet at 193nm.

Extreme ultraviolet, at 13.5 nanometers, was the next step, and it nearly broke the industry. EUV light is absorbed by almost everything, including air and glass. No lens on Earth can focus it. The solution, decades in the making, was to abandon lenses entirely and bounce the light off a series of precision mirrors inside a vacuum chamber.

The road was long. A Japanese engineer, Hiroo Kinoshita, demonstrated the first EUV images in 1986. Bell Labs affirmed the approach in 1991. In 1996 the U.S. Department of Energy formed a consortium with industry to prove a working prototype. ASML acquired Silicon Valley Group in 2001, consolidating the key intellectual property, and by 2018 had brought EUV to full commercial maturity as the only supplier.

Exploding tin, 50,000 times a second

Generating EUV light is the machine's first miracle. A droplet generator releases approximately 50,000 microscopic droplets of molten tin per second, each about 30 microns across. Tin is used because, when ionized, it emits light most efficiently at exactly the 13.5-nanometer wavelength.

Each droplet is struck twice. A pre-pulse laser first flattens it to increase its surface area. Then a high-power carbon dioxide laser, delivering a 30-kilowatt pulse, slams into it and heats the tin to roughly 500,000 degrees Celsius. That is 40 to 90 times hotter than the surface of the Sun. The tin becomes a plasma that radiates extreme ultraviolet light, among the hottest sustained reactions in any industrial process on Earth.

Fifty thousand miniature suns per second, all to draw lines thinner than a virus.

Mirrors polished to atoms

Creating the light is only half the job. The EUV beam must then be collected, focused, and projected through a patterned mask onto the wafer, all without ever touching a lens or passing through air.

The system routes the beam through 11 to 13 mirrors made by Carl Zeiss SMT of Germany. Each mirror is polished to about 0.1 nanometer accuracy across a surface half a meter wide, using multilayer molybdenum-silicon coatings and ion beam figuring. A wafer stage positions the silicon with sub-nanometer accuracy beneath them. The partnership is so deep that ASML owns a 25% stake in Zeiss SMT.

Each machine exposes roughly 150 to 200 wafers per hour, and since every wafer holds hundreds of chips, a single system patterns well over 100,000 chips every hour. Dozens of exposures per chip layer build up the billions of transistors inside a modern processor.

The $200 million price tag

Each EUV system costs on the order of $200 million (analysts put the 2023 average near 150 million euros), weighs about 331,000 pounds, and ships in 250 crates requiring multiple cargo aircraft. Inside are more than 100,000 parts from over 5,000 suppliers across 60 countries: Zeiss mirrors, Trumpf lasers, Cymer plasma sources, precision vacuum and motion systems.

Assembly takes 12 to 18 months per unit, and ASML ships only 50 to 70 machines a year. That scarcity is why just three companies, TSMC, Samsung, and Intel, operate EUV at scale. The economics are punishing in another way too: each system draws roughly a megawatt of power, yet nearly 98% of the generated EUV light is lost, absorbed by the very mirrors that make the process possible, before it ever reaches the wafer.

What comes next

The current machines are approaching their resolution limits, so ASML is moving to High-NA EUV. The EXE:5200 series raises the numerical aperture from 0.33 to 0.55, focusing light more tightly, and is expected to improve light collection by around 70%. These systems target 2nm-class processes and beyond.

Meanwhile the monopoly faces its first serious challenge. Reuters reported in December 2025 that China had developed its own prototype EUV lithography system, alongside alternative approaches like accelerator-based light sources. Foundries are also stretching today's tools by mixing EUV for the finest layers with cheaper deep-ultraviolet for the rest.

EUV took five decades to go from laboratory curiosity to the foundation of the digital economy. Whatever replaces or extends it will define what computers can become next.