Droplet Target Delivery Method for High Pulse Rate Laser Plasma Extreme Ultraviolet Light Source (EU)

A laser-plasma, EUV radiation source that controls the target droplet delivery rate so that successive target droplets are not affected by the ionization of a preceding target droplet. A source nozzle of the source has an orifice of a predetermined size that allow the droplets to be emitted at a rate set by the target materials natural Rayleigh instability break-up frequency as generated by a piezoelectric transducer. The rate of the droplet generation is determined by these factors in connection with the pulse frequency of the excitation laser so that buffer droplets are delivered between the target droplets. The buffer droplets act to absorb radiation generated from the ionized target droplet so that the next target droplet is not affected