Droplet generator and method of servicing extreme ultraviolet radiation source apparatus

An extreme ultra violet (EUV) radiation source apparatus, comprising:

• a target droplet generator for generating a metal droplet;
• a cleaner blasting assembly;
• and
• a chamber enclosing at least the target droplet generator and the cleaner blasting assembly,
• wherein the cleaner blasting assembly comprises:
• a supporting device configured to form pressurized dry ice particles;
• and
• a blasting device configured to eject the pressurized dry ice particles toward a residual material at a nozzle of the target droplet generator.

A method of cleaning an extreme ultra violet (EUV) radiation source apparatus, comprising:

• providing a cleaner blasting assembly having a cleaner blasting nozzle and a cleaner supporting member;
• forming pressurized dry ice particles from the cleaner supporting member;
• ejecting the pressurized dry ice particles through the cleaner blasting nozzle toward a residual material at a nozzle of a target droplet generator;
• and
• removing the residual material from the target droplet generator.