Extreme ultraviolet light source

Abstract

An apparatus for generating EUV radiation is disclosed which may include a target material, a system generating a laser beam for interaction with the target material and a pair of electrodes. A pulse power electrical circuit may be provided for generating a discharge between said electrodes to produce EUV radiation from said target material.

1 . An apparatus comprising:
 A target material:   a system generating a laser beam for interaction with the target material;   a pair of electrodes; and   a pulse power electrical circuit coupled to said electrodes for generating a discharge in a discharge region to produce EUV radiation from said target material.   
     
     
         2 . The apparatus of  claim 1  wherein the target material comprises a liquid metal. 
     
     
         3 . The apparatus of  claim 1  wherein the target is delivered to the discharge region using laser induced ablation. 
     
     
         4 . The apparatus of  claim 1  wherein the target is delivered to the discharge region using laser induced evaporation. 
     
     
         5 . The apparatus of  claim 1  wherein the laser beam is a pulsed laser beam having pulses with pulse durations between 10 ns to 30 ns. 
     
     
         6 . The apparatus of  claim 1  wherein the laser beam interacts with the target material in a chamber and wherein a cleaning buffer gas comprising hydrogen is disposed within the chamber. 
     
     
         7 . The apparatus of  claim 1  further comprising at least one grazing incidence collection optic. 
     
     
         8 . A method comprising the steps of:
 providing a target material:   generating a laser beam for interaction with the target material;   providing a pair of electrodes; and   connecting a pulse power electrical circuit to said electrodes;   using said electrodes to generate an electrical discharge in a discharge region to produce EUV radiation from said target material.   
     
     
         9 . A method as recited in  claim 8  wherein said step of generating a laser beam for interaction with the target material is performed before said step of using said electrodes to generate an electrical discharge in a discharge region to produce EUV radiation from said target material. 
     
     
         10 . A method as recited in  claim 8  wherein the target material comprises a liquid metal. 
     
     
         11 . A method as recited in  claim 8  wherein the target is delivered to the discharge region using laser induced evaporation. 
     
     
         12 . An apparatus comprising:
 a target material:   a first laser beam travelling along a first beam path for interaction with the target material to produce EUV radiation from said target material; and   a second first laser beam travelling along a second beam path for interaction with the target material to produce EUV radiation from said target material.   
     
     
         13 . The apparatus of  claim 12  wherein the first laser beam is generated by a first laser source and the second first laser beam is generated by a second laser source. 
     
     
         14 . The apparatus of  claim 12  wherein the target material comprises tin. 
     
     
         15 . The apparatus of  claim 12  wherein the laser beams interact with the target material at different times. 
     
     
         16 . The apparatus of  claim 12  wherein the first laser beam comprises a pre-pulse interaction with the target material. 
     
     
         17 . The apparatus of  claim 12  further comprising a third laser beam travelling along a third beam path for interaction with the target material to produce EUV radiation from said target material. 
     
     
         18 . The apparatus of  claim 12  further comprising an optic for focusing the first laser beam to a focal spot having a diameter less than 100 μm. 
     
     
         19 . The apparatus of  claim 12  wherein the first laser beam and the second laser beam spatially overlap at a common focus. 
     
     
         20 . The apparatus of  claim 12  wherein the first laser beam is a pulsed laser beam having pulses with pulse durations between 10 ns to 30 ns.