That's not what the information implies
What information? SMIC has been delivering 7nm chips for years.
The quadruple patterning approach does not seem viable even if they can deliver products with 7nm
Every single manufacturer (Samsung, TSMC, Intel) uses multiple patterning, it’s inevitable and in no way “not viable”. China’s problem is that they don’t have access to better equipment, so even multiple patterning techniques are not enough for good 5 nm.
Well…