The lithographic machine limit is about 1nm.
At present, the highest process of the lithography machine can be mass-produced for 4nm, as the world's two major foundry giants TSMC and Samsung can technically reach 3nm, and the factory is also in preparation. At present, the limit is close, because the length of the nm unit is about the length of four silicon atoms, and as a smaller process technology, the structure of the GAA architecture of the new silicon transistor is three-dimensional, which determines that the limit of the technology can not be less than 1nm.
The processing limit of the lithography machine is 1nm. Now TSMC can mass produce 5nm chips. Others are still in research and trial production.