I read an article about the history of extreme ultraviolet lithography (http://dx.doi.org/10.1116/1.2127950, the full pdf is on sci-hub) which says that soft x-ray reduction lithography using multilayer-coated schwertzchild optics was demonstrated in 1986.
3 nm process nodes have a contacted gate pitch of 48 nanometers, and a tightest metal pitch of 24 nanometers, so a laser with wavelength near 13.5 nm is needed to etch the circuits onto the chip dies with sufficient precision.
Of course, there were many practical engineering challenges with getting this concept to work at scale (there is a video by veritasium which discusses this in more detail), and I think very few people making compute forecasts in 1990 would have accurately predicted the trajectory of this technology.
I read an article about the history of extreme ultraviolet lithography (http://dx.doi.org/10.1116/1.2127950, the full pdf is on sci-hub) which says that soft x-ray reduction lithography using multilayer-coated schwertzchild optics was demonstrated in 1986.
3 nm process nodes have a contacted gate pitch of 48 nanometers, and a tightest metal pitch of 24 nanometers, so a laser with wavelength near 13.5 nm is needed to etch the circuits onto the chip dies with sufficient precision.
Of course, there were many practical engineering challenges with getting this concept to work at scale (there is a video by veritasium which discusses this in more detail), and I think very few people making compute forecasts in 1990 would have accurately predicted the trajectory of this technology.