Optical lithographic system having a dynamic coherent optical system

Claim 1

An optical lithographic system comprising: A. a first substrate; B. an ultraviolet source of illumination; C. a dynamic coherent optical condenser coupled to receive said illumination from said ultraviolet source, said condenser having a frequency cutoff typical of an incoherent optical condenser and which has high contrast and resolution typical of a coherent optical condenser; D. a mask including a desired image to be exposed on said first substrate; E. an ultraviolet sensitive photoresist layer on said first substrate whose sensitivity is substantially matched to that of said ultraviolet source of illumination; F. a reflective optical imaging system for imaging a representation of said mask onto said photoresist layer, said optical imaging system comprising a Cassagrain-type telescope design having a primary focusing mirror with a central obscuration, wherein the diameter of said obscuration is less than one-third the diameter of said primary focusing mirror; and G. means for focusing said representation of said mask produced by said optical system onto said photoresist layer to within a predetermined depth of focus.