Note: design and licensing is a far cry for semiconductor fabbing, and not every country can do the latter.
Most countries depend ridiculously much on TSMC (from Taiwan), while TSMC depends ridiculously much on instruments from ASML (from the Netherlands). Grossly simplified, getting where those two currently are takes a decade, and by that time they’ll be a decade ahead (unless they get lazy).
As far as I recall, Samsung (South Korea) can fabricate large quantities of semiconductors on their own (but several times less than TSMC). Then come several Chinese companies, one in the US and one in Israel. Beyond that, there’s very small fish. The only European foundry worth mentioning (X-Fab) has dropped out of the top 10.
I really like to build from zero, but some things are better copied, no matter if you fully understand them or fall short. :)
For example, I’m not qualified to check if Hamilton and Euler were correct - I only do as they explained, and later double-check the output against input.