By Ed Sperling
Continuing to rely on 193nm immersion lithography with multiple patterning is becoming much more difficult at 7nm and 5nm.
With the help of various resolution enhancement techniques, optical lithography using a deep ultraviolet excimer laser has been the workhorse patterning technology in the fab since the early 1980s. It is so closely tied with the continuation of Moore’s Law that it is difficult to think of one without the other. But how much longer this technology can continue isn’t clear, given the magnitude and breadth of the problems expected at upcoming nodes.