Lithography in a quantum world

Abstract

Abstract The conceptualization of the lithography process as captured in models was long based primarily on classical physics. It is now essential to model the lithography process at the quantum level. Photon shot noise and molecular inhomogeneity in resists lead to line-edge roughness and stochastic defects. To contain photon shot noise while maintaining good scanner throughput for EUV lithography requires very powerful light sources. Resists in the future will need to be single-component, and molecular building blocks will need to be much smaller than 0.5 nm. This precludes the long-term use of chemically amplified resists for EUV lithography, at least for minimum line/space patterns. Because the radiation chemistry of EUV resists is driven by photoelectrons and secondary electrons, the range and stochastics of these electrons needs to be considered in the design of future resists. Invention and innovation in patterning materials will be needed to a greater degree than before.