The Nikon Metrology Laser Radar system focuses a beam from a fiber to a target object and receives the light scattered from the target through the same fiber. The system can, among other things, make highly accurate measurements of the position of a tooling ball by locating the angular position of peak signal quality, which is related to the fiber coupling efficiency. This article explores the relationship between fiber coupling efficiency and focus condition.

Historically, illumination design has been linked with the development of microlithography technologies and many tricks have been developed to achieve resolutions below the classical definition. This is a review of illumination engineering in microlithography development.

Illumination has been a critical factor to producing good imaging in microlithography since the beginning. Early lithographers used very simple illumination schemes, but as they improved their understanding of how the illumination influences image fidelity and resolution they moved into more complex partially coherent illumination conditions. Today, lithographers deploy many tricks with coherence and polarization that are tightly coupled with the patterns being imaged to help achieve seemingly impossible resolutions well below the classical definition. In this talk we review the progress of illumination engineering in microlithography up to the present.