I can split any small pitch exposure into separate, larger pitch exposures. For instance, if I need 40nm pitch, and my system is limited to 80nm, I can do 4 exposures. The next shrink requires 8.
To figure this out, draw a square, and each node is an exposure.
This process works forever in theory, but is limited in practice by the mutual registration of the exposures.
To figure this out, draw a square, and each node is an exposure.
This process works forever in theory, but is limited in practice by the mutual registration of the exposures.