The theory developed for perturbed apsheric singlets is used to design a minimum aspheric component optical circuit for use in VLSI. The specification is for a circuit with optical reduction of 10:1 with flat field imaging of a 100mm diameter object field and a resolution of 0.5μm or better. A discussion of the minimising procedure is given together with the theoretically expected performance of the circuit using numerically generated holograms.
D. J. Nicholas,
"Multiple Aspheric Systems For The Lithography Of VLSI Circuits", Proc. SPIE 0645, Optical Manufacturing, Testing and Aspheric Optics, (3 November 1986); doi: 10.1117/12.964492; https://doi.org/10.1117/12.964492