My informed amateur opinion is that no one really knows. There's no case law on this that I'm aware of.
Basically: the "shape of a transistor" (and highly tuned structures like SRAM & flash cells, etc...) in modern logic processes is itself a tightly guarded secret. Outside some crappy electron microcroscopy done by people like Chipworks and the much-prettier-but-really-spun pictures released by the fab's marketing departments, no one involved in the process releases anything.
Now, maybe that's because it's that the masks are ultimately copyrighted by the fab and protected. Or maybe if they leaked they'd be perfectly fine. But what really happens in practice is that before the fab will consent to make your chips for you, they force you to sign an elaborate NDA with no doubt huge contractual penalties.
Again, I don't expect this to change. Silicon fabrication at the mask level will not be open source any time soon, though maybe there's hope that open source tooling might arrive. We just won't be able to see its output.
Basically: the "shape of a transistor" (and highly tuned structures like SRAM & flash cells, etc...) in modern logic processes is itself a tightly guarded secret. Outside some crappy electron microcroscopy done by people like Chipworks and the much-prettier-but-really-spun pictures released by the fab's marketing departments, no one involved in the process releases anything.
Now, maybe that's because it's that the masks are ultimately copyrighted by the fab and protected. Or maybe if they leaked they'd be perfectly fine. But what really happens in practice is that before the fab will consent to make your chips for you, they force you to sign an elaborate NDA with no doubt huge contractual penalties.
Again, I don't expect this to change. Silicon fabrication at the mask level will not be open source any time soon, though maybe there's hope that open source tooling might arrive. We just won't be able to see its output.