Compact light source for metrology applications in the EUV range

摘要

A compact light source based on electron beam accelerator technology includes a storage ring, a booster ring, a linear accelerator and an undulator for providing light having the characteristics for actinic mask inspection at 13.5 nm. The booster ring and the storage ring are located at different levels in a concentric top view arrangement in order to keep the required floor space small and to reduce interference effects. Quasi-continuous injection by enhanced top-up injection leads to high intensity stability and combats lifetime reductions due to elastic beam gas scattering and Touschek scattering. Injection into the storage ring and extraction from the booster ring are performed diagonal in the plane which is defined by the parallel straight section orbits of the booster ring and the storage ring. For the top-up injection from the booster ring into the storage ring two antisymmetrically arranged Lambertson septa are used.