China actually can indigenously produce 7nm chips based on this article:
"China's Shanghai Micro Electronics Equipment (SMEE), founded in 2002, announced that it was building on its previous 90nm to produce the first China-made 28nm immersion type lithography machine, which will be delivered in 2021-2022. This means it can produce 12nm -14nm Chips, but with multiple patterning techniques will be able to reach 7nm."
-It also can produce 5nm but require more layer and more advance DUV machine.
EUV 12 layers at 7nm versus 68 DUV layers.
EUV 22 layers at 5nm vs 78 DUV layers.