Nikon and Canon's absence from EUV lithography is documented as consortium exclusion followed by a strategic exit, not a demonstrated technical failure to imitate ASML/Zeiss's tacit know-how

Brian Potter's Construction Physics account states that when the US-led EUV-LLC consortium formed in the mid-1990s, "Nikon declined to participate in EUV-LLC in part due to the resulting controversy, and Canon was ultimately prevented from joining by the US government," and concludes: "Left outside of the EUV-LLC consortium, Nikon and Canon never successfully developed EUV technology." Samo Burja's ASML piece adds the later chapter: Nikon "built a working prototype in 2008 but delayed and eventually abandoned its EUV program after the 2008 global financial crisis and Intel's 2012 decision to invest in ASML, signaling its commitment to buying their machines." Both accounts describe Nikon as having reached a working EUV prototype (2008) before exiting for financial and strategic-signaling reasons — a different story from the "15+ years" of failed attempts to enter that claim-euv-mirror-advantage-is-tacit-know-how-not-patent originally described, which implies persistent, unsuccessful technical effort rather than exclusion from an information-sharing consortium followed by a business decision to stop once the market had visibly consolidated around ASML.

This does not refute the general tacit-knowledge thesis (claim-burja-and-ip-business-academy-source-asml-zeiss-euv-moat-to-tacit-know-how) as an account of why a new entrant would struggle today. It means the specific causal chain — Nikon/Canon tried for 15+ years and were blocked by tacit know-how specifically — conflates two better-documented mechanisms (consortium/political exclusion; a later strategic exit) with a technical-imitation failure that neither Tier-2 source actually describes for Nikon or Canon by name.