Shroud nozzle for gas jet control in an extreme ultraviolet light source

A gas jet nozzle for an extreme ultraviolet light (EUV) source, comprising:

• a housing adapted to couple to a primary gas source and adapted to expel a first gas/droplet stream, said housing comprising a primary channel located within said housing adapted to expel said first gas/droplet stream, said housing further comprising a secondary channel adapted to couple to a secondary gas source and adapted to expel a second gas stream to shape said first gas stream expelled by said primary channel, said secondary channel being a tapered channel so that the secondary gas expands as it travels through the second channel to be expelled therefrom, wherein said secondary channel is configured such that said second gas stream expelled from said secondary channel restricts the lateral expansion of said first gas/droplet stream expelled from said primary channel, optimizing gas jet properties.

A method of converting laser energy to EUV energy, comprising the steps of:

• expelling gas from a nozzle, said nozzle comprising a housing having a primary channel and a secondary channel, said primary channel being coupled to a primary gas source, said secondary channel being coupled to a secondary gas source, wherein a first gas/droplet stream is expelled from said primary channel and a second gas stream is expelled from said secondary channel, said secondary channel being a tapered channel so that the secondary gas expands as it travels through the second channel to be expelled therefrom, said second gas stream shaping said first gas/droplet stream;
• and
• illuminating said shaped first gas/droplet stream with a laser to produce EUV light-emitting plasma.