I don't blame you, the headlines make it seem like there's only 1 true correct path, but that's all post-hoc justification.
What exactly is economical about using a 100 kW CO2 laser that weighs 10000+ kgs alone to shoot liquid tin droplets in vacuum that's in another 10+ ton system? liquids and vacuum doesn't mix well, exploding metallic liquids even less so, so you need a very sophisticated metal management system to handle the outgassing and cleanup of lenses. And that's not even getting to the optics transmission train, wafer stage, etc.
Just a
single EUV instrument can buy the
entire Shanghai Synchrotron.
The difference is the Shanghai Synchrotron has 16 beamlines, not 1, and are energy tunable.
Note that they're using EUV
interference lithography here. Interference lithography is
maskless. Wave interference is only meaningful with coherent light. Regular EUV is not a laser. It
uses a laser as the energy source for Sn droplet excitation, but the EUV itself, emitted by the Sn droplets, is isotropic.
Synchrotrons produce coherent EUV, which opens up tons of possibilities that don't exist with incoherent LPP EUV. It's not a mere economic advantage (more beamlines for the price of 1), it's a technical one.
And this is not even a synchrotron optimized for EUV production, it just happens to have this capability at 1 beamline station.
