摘要 |
The invention is directed to an arrangement for monitoring the energy radiated by an EUV radiation source with respect to energy variations acting in an illumination beam path, wherein the radiation source has a plasma column emitting extreme ultraviolet radiation. The arrangement includes an energy monitoring unit, and a detection beam path. The detection beam path is separate from the illumination beam path and is arranged with the energy monitoring unit for detecting pulse energy, so that the illumination beam path is not impaired by the energy measurement. The detection beam path is matched to the illumination beam path with respect to bundle extension and optical losses.
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