Illumination system for EUV projection lithography
AssigneeCarl Zeiss SMT GmbH
InventorsMichael Patra, Ralf Mueller
Life of this patent
Estimating the term…
Abstract
An illumination system for EUV projection lithography has a beam shaping optical unit for generating an EUV collective output beam from an EUV raw beam of a synchrotron-radiation-based light source. An output coupling optical unit serves for generating a plurality of EUV individual output beams from the EUV collective output beam. In each case a beam guiding optical unit serves for guiding the respective EUV individual output beam toward an object field in which a lithography mask is arrangable. The result is an illumination system with which EUV light of a synchrotron-radiation-based light source is guided to the greatest possible extent without losses and at the same time flexibly.
Claims24
A beam shaping optical unit, comprising:
- at least two groups of mirrors on which EUV radiation impinges with grazing incidence during use of the beam shaping optical unit,
- wherein each mirror group has a common group incidence plane, the group incidence planes of the mirror groups differ from one another, and the beam shaping unit is an EUV lithography beam shaping unit, and
- wherein:
- the beam shaping optical unit comprises first, second and third groups of mirrors;
- all mirrors of the first group of mirrors are in a beam path downstream of a first mirror of the second group of mirrors;
- and
- all the mirrors of the first group of mirrors are upstream of a last mirror of the third group of mirrors.
A beam shaping optical unit, comprising:
- at least two groups of mirrors on which EUV radiation impinges with grazing incidence during use of the beam shaping optical unit,
- wherein each mirror group has a common group incidence plane, the group incidence planes of the mirror groups differ from one another, and the beam shaping unit is an EUV lithography beam shaping unit, and
- wherein the angles of incidence of the EUV radiation on at least two mirrors of one of the mirror groups differ.
An illumination system, comprising:
- a beam shaping optical unit comprising at least two groups of mirrors on which EUV radiation impinges with grazing incidence during use of the beam shaping optical unit,
- wherein:
- each mirror group has a common group incidence plane, the group incidence planes of the mirror groups differ from one another;
- the beam shaping unit is an EUV lithography beam shaping unit;
- the illumination system is an EUV illumination system;
- and
- the beam shaping optical unit configured to generate an EUV collective output beam from an EUV raw beam of a synchrotron-radiation-based light source.
Dependencies are inferred from the claim text.