It's more than half.
Even if given you half, half is enough damage to slow them big time.
That's my opinion and you can have yours
ASML has already developed the EUV machine and underlying technologies.
SMIC ordered the B Model.
But now, ASML has a C model.
My understanding is that this improves modularity and maintenance, rather than the underlying technology.
So how does China embargoing EUV technologies really slow ASML?
With China cutting itself out of the global supply chain, and industries leaving China, ASML would still be able to address at least 75% of the global market.
So a Chinese embargo of EUV technology may result in a
marginal slowdown in ASML developing what comes next after EUV, but that is another 10+ years away. But at the cost of China losing influence, expertise, money etc
It doesn't change the Chinese response, which is fundamental research in new technologies which will replace current EUV tech in 5+ years.
Nor should China stop seeking to match current EUV systems.
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It also raises the point whether sub-3nm semiconductors are economically viable or desirable from a Huawei perspective.
I've seen an estimate that the chip design cost at 5nm (2020) is typically $543M.
And that the design cost at 3nm (2024) is $500M to $1500M.
Presumably the design cost at 2nm (2028?) would be $1000M+
Is designing and manufacturing a sub-3nm chip for consumer purposes still economically viable?
With the consumer smartphone processor volumes that we see from Samsung/Apple/Huawei, it looks like the cost-benefit threshold is between 3nm-5nm. Huawei has already been allocated 5nm/7nm capacity by TSMC and 6nm capacity by Samsung.
And SMIC should be able to get down to 7nm in the next few years, which Huawei should still have access to.
But the vast majority of Huawei products (and sales) are mostly in consumer/industrial sectors where the optimum cost-benefit requires older process technology.