Dutch company and the world's sole manufacturer of extreme-ultraviolet (EUV) lithography machines, which use light with a wavelength of 13.5 nanometres to etch the circuit patterns that make up a microchip onto wafers of silicon. ASML spent decades perfecting the technology. In the same way that a calligraphy pen can draw more precisely than a crayon, shorter wavelengths of light allow finer details to be etched, enabling the production of chips with the tiniest transistors.
Only three firms—Samsung, TSMC and (to a degree) Intel—can make chips with the very smallest transistors, and all rely on ASML's EUV machines to do so.
In October 2025 Substrate, an American startup backed by Peter Thiel's Founders Fund, was unveiled with the ambition of building a chipmaking machine using advanced X-ray lithography to challenge ASML's monopoly and revive American semiconductor production. The firm has raised $100m at a valuation of $1bn.
Under American pressure, ASML will not sell EUV machines to Chinese chipmakers. China's only option is therefore to push older "deep ultra-violet" (DUV) systems, which use 193nm light, to their limits. One tactic is "multi-patterning": instead of exposing a wafer to the light source once, engineers repeat the process several times, building up smaller features that would be impossible to produce in a single pass. Multi-patterning adds cost, slows production and reduces yield (the proportion of chips on each wafer that are free from defects). Most analysts reckon that, unless China can secure a supply of ASML's EUV machines, large-scale production of the most advanced chips is still years away.
The executioner is, I hear, very expert, and my neck is very slender.