US Patent 12133318 Rotating target for extreme ultraviolet source with liquid metal

An extreme ultraviolet (EUV) light source includes a vacuum chamber with a rotating target assembly therein. The rotating target assembly has an annular groove with a distal wall relative to an axis of rotation. The distal wall includes a porous region. The rotating target assembly is rotated to form a target by centrifugal force with a layer of molten metal on a distal wall of an annular groove in the rotating target assembly.