US 12,146,740 B2
Method and system for measuring a surface topography of an object
Daniel Bublitz, Rausdorf (DE); and Peter Westphal, Jena (DE)
Assigned to Carl Zeiss Industrielle Messtechnik GmbH, Oberkochen (DE)
Appl. No. 17/998,599
Filed by Carl Zeiss Industrielle Messtechnik GmbH, Oberkochen (DE)
PCT Filed May 12, 2021, PCT No. PCT/EP2021/062655
§ 371(c)(1), (2) Date Nov. 13, 2022,
PCT Pub. No. WO2021/228959, PCT Pub. Date Nov. 18, 2021.
Claims priority of application No. 10 2020 113 159.3 (DE), filed on May 14, 2020.
Prior Publication US 2023/0204339 A1, Jun. 29, 2023
Int. Cl. G01B 9/021 (2006.01); G01B 9/02 (2022.01); G01B 11/30 (2006.01)
CPC G01B 9/021 (2013.01) [G01B 9/02094 (2013.01); G01B 11/303 (2013.01)] 26 Claims
OG exemplary drawing
 
1. A method for measuring a surface topography of an object, the method including the following steps:
a) providing source radiation and splitting the source radiation into illumination radiation and reference radiation,
b) illuminating the surface of the object with the illumination radiation at a two-dimensionally extended illumination field, the surface of the object being illuminated simultaneously with more than one spatial radiation mode, and radiation modes of the illumination being spatially and temporally coherent but having a fixed phase difference from one another, and
c) superimposing illumination radiation scattered back at the surface of the object with the reference radiation, and detecting an interference signal of the superimposed radiations with at least one detector,
wherein steps a) to c) are carried out for at least two different fixed wavelengths and the surface topography of the object is determined by of holography evaluation.