Patent ID: 8872123
Filing Date: 2014-10-28
Classification: G21K,H05G

Abstract:
1. A method of regulating a dose of energy produced during continuous burst mode of an EUV light source comprising: (a) beginning a burst having a predetermined energy dose target; (b) timing by the laser controller a trigger to pulse a laser beam to irradiate a droplet during the burst; (c) sensing EUV energy generated by the droplet; (d) calculating by the laser controller a current dose error for the droplet based on the sensed EUV energy and the energy dose target; (e) accumulating by the laser controller a burst error based on the current dose error and a running burst error calculated for one or more preceding droplet during the burst; (f) repeating steps (b)-(e) for a next droplet when the burst is not finished and the accumulated burst error does not meet or exceed a threshold burst error; (g) mistiming by the laser controller the trigger to pulse the laser beam to not irradiate the next droplet when the burst is not finished and the accumulated burst error meets or exceeds the threshold burst error; and (h) repeating steps (c)-(g) until the burst is finished.