公开(公告)号：US20220236648A1

公开(公告)日：2022-07-28

申请号：US17721750

申请日：2022-04-15

Applicant: Carl Zeiss SMT GmbH

Inventor： Renzo Capelli ,  Markus Koch ,  Dirk Hellweg ,  Walter Pauls ,  Grizelda Kersteen ,  Klaus Gwosch

IPC: G03F7/20

Abstract: When measuring a reflectivity of an object for measurement light, initially the object and a reflectivity measurement apparatus are provided. The latter includes a measurement light source, an object holder for holding the object and a spatially resolving detector for capturing measurement light reflected by the object. A measurement light beam impinges on a section of the object within a field of view of the measurement apparatus. The reflected measurement light coming from the impinged-upon section of the object is captured. A surface area of the captured section is at most 50 μm×50 μm. The measurement is performed by the detector. Next, at least one reflectivity parameter of the object is determined on the basis of an intensity of the captured measurement light. The result is a measurement method and a metrology system operating therewith, whereby reflectivities in particular of very finely structured objects, such as lithography masks, can be measured with sufficient precision.

公开(公告)号：US20240085783A1

公开(公告)日：2024-03-14

申请号：US18512872

申请日：2023-11-17

Applicant: Carl Zeiss SMT GmbH

Inventor： Markus Raab ,  Stefan Troeger ,  Sascha Bleidistel ,  Thilo Pollak ,  Alexander Vogler ,  Klaus Gwosch ,  Andreas Koeniger ,  Matthias Manger

IPC: G03F7/00 ,  G01L1/22 ,  G01L1/24 ,  G02B6/02 ,  G02B6/293 ,  G02B6/38 ,  G02B6/42

CPC classification number: G03F7/0005 ,  G01L1/2287 ,  G01L1/246 ,  G02B6/02152 ,  G02B6/2935 ,  G02B6/3861 ,  G02B6/4298

Abstract: An optical apparatus for a lithography system comprises at least one optical element comprising an optical surface. The optical apparatus also comprises one or more actuators for deforming the optical surface. A strain gauge device is provided for determining the deformation of the optical surface. The strain gauge device comprises at least one optical fiber that maintains polarization.

公开(公告)号：US20230168593A1

公开(公告)日：2023-06-01

申请号：US17992034

申请日：2022-11-22

Applicant: Carl Zeiss SMT GmbH

Inventor： Renzo Capelli ,  Klaus Gwosch

IPC: G03F7/20 ,  G03F1/84

CPC classification number: G03F7/7085 ,  G03F1/84 ,  G03F7/70033 ,  G03F7/702 ,  G03F7/70775

Abstract: A metrology system serves for examining objects with EUV measurement light. An illumination optical unit serves for guiding the EUV measurement light towards the object to be examined. The illumination optical unit has an illumination optical unit stop for prescribing a measurement light intensity distribution in an illumination pupil in a pupil plane of the illumination optical unit. An output coupling mirror serves for coupling a part of the measurement light out of an illumination beam path of the illumination optical unit. The output coupling mirror has a mirror surface which is used to couple out measurement light and has an aspect ratio of a greatest mirror surface extent A longitudinally with respect to a mirror surface longitudinal dimension (x) to a smallest mirror surface extent B longitudinally with respect to a mirror surface transverse dimension (y) perpendicular to the mirror surface longitudinal dimension (x). The aspect ratio AB is greater than 1.1. The result is a metrology system in which a measurement light throughput is optimized even in the simulation or emulation of an imaging optical unit of a projection exposure apparatus having an image-side numerical aperture of greater than 0.5 and in particular in the simulation or emulation of an anamorphic imaging optical unit.

公开(公告)号：US20220381643A1

公开(公告)日：2022-12-01

申请号：US17664773

申请日：2022-05-24

Applicant: Carl Zeiss SMT GmbH

Inventor： Klaus Gwosch ,  Markus Koch ,  Lars Stoppe ,  Manuel Decker ,  Lukas Fischer

IPC: G01M11/02

Abstract: To determine an imaging quality of an optical system when illuminated by illumination light within an entrance pupil or exit pupil, a test structure is initially arranged in an object plane of the optical system and an illumination angle distribution for illuminating the test structure with the illumination light is specified. The test structure is illuminated at different distance positions relative to the object plane. An intensity of the illumination light is measured in an image plane of the optical system, the illumination light having been guided by the optical system when imaging the test structure at each distance position. An aerial image measured in this way is compared with a simulated aerial image and fit parameters of a function set for describing the simulated aerial image are adapted and a wavefront of the optical system is determined on the basis of the result of a minimized difference.

公开(公告)号：US12158703B2

公开(公告)日：2024-12-03

申请号：US17969967

申请日：2022-10-20

Applicant: Carl Zeiss SMT GmbH

Inventor： Lukas Fischer ,  Klaus Gwosch ,  Markus Koch ,  Mario Laengle ,  Daniel Pagel

IPC: G03F7/00

Abstract: An optical measuring system is used to reproduce a target wavefront of an imaging optical production system when an object is illuminated with illumination light. The optical measuring system comprises an object holder displaceable by actuator means and at least one optical component displaceable by actuator means. Within the scope of the target wavefront reproduction, a starting actuator position set (X0), in which each actuator is assigned a starting actuator position, is initially specified. An expected design wavefront (WD) which approximates the target wavefront and which the optical measuring system produces as a set wavefront is determined. A coarse measurement of a starting wavefront (W0) which the optical measuring system produces as actual wavefront after actually setting the starting actuator position set (X0) is carried out. Then, the object holder is adjusted by actuator means until a coarse target wavefront (W1) is obtained for a coarse actuator position set (X1) in the case of a minimum wavefront deviation between the actual wavefront and the design wavefront (WD). Said coarse target wavefront is then subjected to a fine measurement and the at least one optical component is displaced until a fine target wavefront (W2) is obtained for a fine actuator position set (X2) in the case of a minimum deviation between the actual wavefront setting-in in that case and the design wavefront (WD). This reproduction method allows wavefront deviations of the optical measuring system generated by way of targeted misalignment to provide a good approximation of corresponding deviations of the optical production system.

公开(公告)号：US20230130187A1

公开(公告)日：2023-04-27

申请号：US17969967

申请日：2022-10-20

Applicant: Carl Zeiss SMT GmbH

Inventor： Lukas Fischer ,  Klaus Gwosch ,  Markus Koch ,  Mario Laengle ,  Daniel Pagel

IPC: G03F7/20

Abstract: An optical measuring system is used to reproduce a target wavefront of an imaging optical production system when an object is illuminated with illumination light. The optical measuring system comprises an object holder displaceable by actuator means and at least one optical component displaceable by actuator means. Within the scope of the target wavefront reproduction, a starting actuator position set (X0), in which each actuator is assigned a starting actuator position, is initially specified. An expected design wavefront (WD) which approximates the target wavefront and which the optical measuring system produces as a set wavefront is determined. A coarse measurement of a starting wavefront (W0) which the optical measuring system produces as actual wavefront after actually setting the starting actuator position set (X0) is carried out. Then, the object holder is adjusted by actuator means until a coarse target wavefront (W1) is obtained for a coarse actuator position set (X1) in the case of a minimum wavefront deviation between the actual wavefront and the design wavefront (WD). Said coarse target wavefront is then subjected to a fine measurement and the at least one optical component is displaced until a fine target wavefront (W2) is obtained for a fine actuator position set (X2) in the case of a minimum deviation between the actual wavefront setting-in in that case and the design wavefront (WD). This reproduction method allows wavefront deviations of the optical measuring system generated by way of targeted misalignment to provide a good approximation of corresponding deviations of the optical production system.

公开(公告)号：US20220390320A1

公开(公告)日：2022-12-08

申请号：US17750947

申请日：2022-05-23

Applicant: Carl Zeiss SMT GmbH

Inventor： Markus Koch ,  Renzo Capelli ,  Klaus Gwosch ,  Dmitry Simakov

IPC: G01M11/02

Abstract: To determine an imaging quality of an optical system when illuminated by illumination light within a pupil to be measured of the optical system and/or to qualify the phase effect of a test structure, a test structure that is periodic in at least one dimension is initially arranged in an object plane of the optical system. An initial illumination angle distribution for illuminating the test structure with an initial pupil region, whose area is less than 10% of a total pupil area, is specified and the test structure is illuminated thereby in different distance positions relative to the object plane. In this way, an initial measured aerial image of the test structure is determined. Specifying the illumination distribution, illuminating and determining the aerial image are then repeated for a further illumination angle distribution and an imaging contribution of the optical system is determined from a comparison of the measured aerial images, the imaging quality parameter to be determined and/or a complex-valued diffraction spectrum of the test structure being determined from said imaging contribution. A metrology system for carrying out the method comprises a holder for the test structure, an illumination optical unit, a specification device for specifying the illumination angle distributions, the optical system to be examined in respect of its imaging quality, and a spatially resolving detection device for determining aerial images. This yields an improved imaging quality determination method.

公开(公告)号：US20240402613A1

公开(公告)日：2024-12-05

申请号：US18679841

申请日：2024-05-31

Applicant: Carl Zeiss SMT GmbH

Inventor： Alexander Winkler ,  Klaus Gwosch ,  Markus Koch

IPC: G03F7/00 ,  G03F1/22

Abstract: A metrology system having an optical measurement system serves to simulate illumination and imaging properties of an optical production system when an object is illuminated and imaged. The optical measurement system has an illumination optical unit serving to illuminate the object and having a pupil stop in the region of an illumination pupil in a pupil plane, and an imaging optical unit for imaging the object in an image plane. At least one pupil stop for specifying a plurality of measurement illumination settings created by displacing the pupil stop in the pupil plane is provided within the scope of the simulation method. Measurement aerial images are recorded in the image plane for various displacement positions of the object perpendicular to the object plane with the various measurement illumination settings. The various measurement illumination settings are specified by displacing the pupil stop. A complex mask transfer function is reconstructed from the recorded measurement aerial images. A 3-D aerial image of the optical production system is determined from the reconstructed mask transfer function and a given illumination setting of the optical production system as the result of the simulation method. The reconstruction includes the fact that profiles of stop edges of the at least one pupil stop which effectively act to specify the respective measurement illumination setting are changed in a manner going beyond a pure displacement of the stop edge when the respective measurement illumination setting is specified on the basis of the displacement position of the pupil stop. This results in an improvement of the simulation method.

公开(公告)号：US20240361704A1

公开(公告)日：2024-10-31

申请号：US18768476

申请日：2024-07-10

Applicant: Carl Zeiss SMT GmbH

Inventor： Klaus Gwosch ,  Markus Koch ,  Renzo Capelli ,  Matthias Roesch ,  Lars Stoppe ,  Manuel Decker

IPC: G03F7/00

CPC classification number: G03F7/70666 ,  G03F7/70625 ,  G03F7/70641 ,  G03F7/706849

Abstract: When simulating illumination and imaging properties of an optical production system when illuminating and imaging an object by use of an optical measurement system of a metrology system, the optical measurement system having an illumination optical unit for illuminating the object and a pupil stop, in particular a displaceable pupil stop, and having an imaging optical unit for imaging the object into an image plane is initially provided. When simulating the properties of the optical production system with the optical measurement system, a plurality of pupil stops are initially provided. Measurement aerial images are then recorded by use of the plurality of pupil stops. A complex mask transfer function is reconstructed from the recorded measurement aerial images and a 3-D aerial image is determined from this function and the illumination setting of the optical production system. This yields an improved simulation method.

公开(公告)号：US20240103381A1

公开(公告)日：2024-03-28

申请号：US18512298

申请日：2023-11-17

Applicant: Carl Zeiss SMT GmbH

Inventor： Klaus Gwosch ,  Pascal Heller ,  Matthias Manger ,  Andreas Koeniger

IPC: G03F7/00

CPC classification number: G03F7/70266 ,  G03F7/7085

Abstract: An optical apparatus for a lithography system has at least one optical element comprising an optical surface. The optical apparatus also has one or more actuators for deforming the optical surface. The optical element comprises a strain gauge device for determining the deformation of the optical surface. The gauge device comprises: a) at least one path length device for generating a measurement spectrum of a measurement radiation, wherein the path length device comprises a grating device for the measurement radiation and/or a resonator device for the measurement radiation; and/or b) at least one waveguide, wherein the at least one waveguide and/or the at least one grating device and/or the at least one resonator device are formed by the substrate element.