The Zeiss & Cymer AllianceWide moat

Two components of an EUV machine are as hard to make as the machine itself, and ASML has locked up both. The first is the optics: the mirrors and lenses¹ that steer 13.5-nanometer light must be the flattest, most perfect surfaces ever manufactured, and only Carl Zeiss — through a specialized subsidiary, in an exclusive decades-long partnership with ASML — can make them. The second is the light source: generating usable EUV light by vaporizing tin droplets² with a laser is a feat unto itself, and it is made by Cymer, which ASML acquired outright in 2013 precisely to control this critical link.

This alliance is the reason the moat is a network rather than a single company's secret. A competitor seeking to build an EUV machine would need optics of Zeiss's caliber and a light source of Cymer's — and both are either owned by ASML or bound to it exclusively, with their own decades of irreproducible expertise. There is no open market to buy these pieces from; ASML has, over decades, either acquired or monopolized the entire critical supply chain for the hardest parts. The monopoly on the finished machine is thus backstopped by control of the irreplaceable components inside it — a moat within the moat, and one of the deepest reasons replication is not merely hard but, for the foreseeable future, foreclosed.