Laser produced plasma EUV light source having a droplet stream produced using a modulated disturbance wave

Abstract

A plasma generating system is disclosed having a source of target material droplets, e.g. tin droplets, and a laser, e.g. a pulsed CO2 laser, producing a beam irradiating the droplets at an irradiation region, the plasma producing EUV radiation. For the device, the droplet source may comprise a fluid exiting an orifice and a sub-system producing a disturbance in the fluid which generates droplets having differing initial velocities causing at least some adjacent droplet pairs to coalesce together prior to reaching the irradiation region. In one implementation, the disturbance may comprise a frequency modulated disturbance waveform and in another implementation, the disturbance may comprise an amplitude modulated disturbance waveform.

Dependencies are inferred from the claim text.