Patent ID: 11906904
Assignee: CARL ZEISS SMT GMBH
Field: Optics (Instruments)
Classification: CPC G | IPC G

Claim 19:
20. A system, comprising:
a projection lens comprising a plurality of optical elements in a beam path of a working wavelength of electromagnetic radiation to image a pattern arranged in an object surface of the projection lens into an image surface of the projection lens via the operating wavelength of the electromagnetic radiation, the plurality of optical elements comprising a replaceable optical element
a correction optical element; and
an interchange device configured to replace the replaceable optical element with the correction optical element,
wherein:
the correction optical element comprises a body comprising a surface which comprises regions consisting of diffraction structures configured to diffract an operating wavelength of electromagnetic radiation;
the regions of the surface of the correction element consist of diffraction structures comprise a first region of the surface of the correction element and a second region of the surface of the correction element
the first region of the surface of the correction element consists of first diffraction structures having a first density of diffraction structures;
the second region of the surface of the correction element consists of second diffraction structures having a second density of diffraction structures;
the second density of diffraction structures is different from the first density of diffraction structures; and
the operating wavelength of the electromagnetic radiation is in the EUV range.