This extra cost for multi-patterning will never allow a 7nm DUV process to be price competitive with EUV at 7nm. It just gets worse going to 5nm DUV, which is supposedly possible with Nikon lithographs, but not competitive economically. Despite the cost, I think if SMEE can upgrade their upcoming 28nm immersion lithograph to a future version that supports below <14nm, the extra cost won't matter. China will literally be forced to buy those <14nm ICs made by SMEE or CETC equipment that they are currently sanctioned from producing with TSMC. It's at that point that I think the Americans will allow China to outsource IC fabrication to >=7nm in order to harm SMEE and CETC lithography sales."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.