EUV lithography

Extreme ultraviolet lithography (EUVL or simply EUV) is a technology used in the semiconductor industry for manufacturing integrated circuits (ICs). It is a type of photolithography that uses 13.5 nm extreme ultraviolet (EUV) light from a laser-pulsed tin (Sn) plasma to create intricate patterns on semiconductor substrates.

As of 2025, ASML is the only company that produces and sells EUV systems for chip production, targeting 5 nanometer (nm) and 3 nm process nodes, though Reuters reported in December 2025 that China had developed its own prototype EUV lithography system, China is also pursuing alternative EUV light-source approaches, including accelerator based Steady-state microbunching (SSMB) and laser-induced discharge plasma (LDP).

The EUV wavelengths that are used in EUVL are near 13.5 nanometers (nm),to produce a pattern by using a reflective photomask to expose a substrate covered by photoresist.

History and economic impact

In the 1960s, visible light was used for the production of integrated circuits, with wavelengths as short as 435 nm (mercury G line).

Later, ultraviolet (UV) light was used, at first with a wavelength of 365 nm (mercury I line), then with excimer wavelengths, first of 248 nm (krypton fluoride laser), then 193 nm (argon fluoride laser), which was called deep UV.

The next step, going even smaller, was called extreme UV, or EUV. EUV light is absorbed by glass and air, so instead of using lenses to focus the beams of light as done previously, mirrors in vacuum would be needed. A reliable production of EUV was also problematic. Then, leading producers of steppers Canon and Nikon stopped development.

While working at Nippon Telegraph and Telephone (NTT) in mid-1980s Japan, engineer Hiroo Kinoshita first proposed the concept of EUV. He tested the idea and successfully demonstrated the first EUV images at a 1986 Japan Society of Applied Physics (JSAP) meeting. Despite initial scepticism in Japan, Kinoshita continued EUV research at NTT and organized joint US-Japan research on EUV in the early 1990s.