Patent ID: 9239269
Filing Date: 2016-01-19
CPC Classification: G01J,G02B,H01S,H05G

Claim Text:
1. A system comprising: an energy monitor within a laser-produced plasma (LPP) extreme ultraviolet (EUV) system, the energy monitor configured to measure a laser beam comprising pre-pulses and main pulses separated by a length of time, the energy monitor comprising: a calibration module configured to determine a power of the first main pulse based on a main pulse calibration coefficient and a pulse integral of a portion of the voltage signal corresponding to the first main pulse, to determine a power of the first pre-pulse based on the average power and the power of the first main pulse, and to determine a pre-pulse calibration coefficient based on the power of the first pre-pulse and an integral of a portion of the voltage signal corresponding to the first pre-pulse; and a single pulse energy calculation (SPEC) module configured to determine an energy of a second pre-pulse based on the pre-pulse calibration coefficient and a pulse integral of a portion of a second voltage signal provided by the PEM detector corresponding to the second pre-pulse, and to determine an energy of a second main pulse based on the main pulse calibration coefficient and a pulse integral of a portion of the second voltage signal to the second main pulse.