EUV collector

An EUV collector configured to transfer an emission of at least one EUV radiation source to a main intensity spot, the EUV collector comprising:

• a collector subunit comprising first and second grazing incidence mirrors arranged one behind the other, the first and second grazing incidence mirrors being configured to transfer EUV radiation from the radiation source to a transfer intensity spot;
• and
• an ellipsoid mirror having an ellipsoidal mirror surface configured so that, during use of the EUV collector, the EUV radiation impinges on the ellipsoidal mirror surface at an angle of incidence below a critical grazing incidence angle,
• wherein:
• the EUV collector has no more than one collector subunit comprising any grazing incidence mirrors in a path of an EUV partial beam between the EUV radiation source and the transfer intensity spot;
• EUV partial beams are emitted by the EUV radiation source so that each EUV partial beam is reflected by no more than one single collector subunit comprising at least one grazing incidence mirror;
• at least some of the EUV partial beams emitted by the EUV radiation source are reflected only by the collector subunit comprising the first and second grazing incidence mirrors;
• the collector subunit is configured to collect a forward emission portion of the emission of the at least one EUV radiation source which is emitted toward the main intensity spot;
• and
• the ellipsoid mirror is configured to collect a backward emission portion of the emission of the at least one EUV radiation source which is emitted away from the main intensity spot.