System and method for controlling droplets of a target material in an EUV light source

摘要

A method and apparatus for generating and using a dual curtain from one laser source within a laser produced plasma (LPP) extreme ultraviolet (EUV) light system and controlling droplet ejection and / or illumination is disclosed.A first set of sensors comprising one or more sensors detects droplets of a target material as it passes through one or more curtains and allows for adjustment of the orientation of the droplet generator, The subsequent droplet is guided to the irradiation site more accurately. A second set of sensors comprising one or more sensors detects droplets as they pass through one or more curtains and determines when the source laser is emitting pulses so that the pulses reach the irradiation site simultaneously with the droplets And decides whether to generate it.(FIG. 4A).