METHOD FOR LPP DRIVE LASER OUTPUT DURING EUV NON-OUTPUT PERIODS

摘要

A device is disclosed, herein which may comprise a droplet generator producing droplets of target material; a sensor providing an. intercept time signal when a droplet reaches a preselected location; a delay circuit coupled with said sensor, the delay circuit generating a trigger signal delayed from the. intercept time signal; a. laser source responsive to a trigger signal to produce a laser pulse-; and a system controlling said delay circuit to provide a. trigger signal delayed from the intercept time by a first delay time to generate a light pulse that is focused on a droplet and a trigger signal delayed from the intercept time by a second delay time to generate a light -pulse which is not focused on a droplet.