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.
US 6,855,943 B2
Application Serial Number
Joint Assignment w/UCFRF
Assignee at Issuance
Agency: Northrop Grumman Corporation
Assignee at Filing
Agency: TRW Inc.
Nonprovisional Application Record
Shields, Henry, "Droplet Target Delivery Method for High Pulse Rate Laser Plasma Extreme UV Light Source" (2005). UCF Patents. 684.