> I don't know much about foundry processes, but it seems that it's taking more and more time for lesser and lesser gains, right? At this rate, how long until w

> I don't know much about foundry processes, but it seems that it's taking more and more time for lesser and lesser gains, right? At this rate, how long until we reach sub nanometer? What are the physical limits on these processes, and does it have any implications for end users? Will we be using 2nm CPUs for 50 years? The lattice constant of crystalline silicon is 0.54 nm, and since it's an FCC structure the distance between neighboring atoms is 0.38 nm. So with a hypothetical 2 nm CPU, some feature would be only roughly 5 atoms across, which leaves VERY little room for manufacturing tolerance. How would one manufacture a device containing billions of transistors with such small tolerances? I don't think we'll ever see such things, at least not with a lithography approach. Heck, I think it's close to black magic that they are able to produce transistors on a 10nm process, but apparently experts say that up to 5nm (13 atoms!!!) might be possible.