Metrologieverfahren mit auf ein Ziel unter mehreren Unterschiedlichen Einfallswinkeln Einfallenden Strahlen und Zugehöriges Metrologiewerkzeug

Details

Veröffentlichungs-Nr.

EP4414785

Aktenzeichen

EP23156294

Anmeldetag

13. Februar 2023

Veröffentlichung

14. August 2024

Rechtsraum

EP

IPC

G03F7/00

Abstract

Disclosed is a metrology method and metrology tool comprising a first dispersive element (810) operable to receive and scatter source radiation (e.g., hard X-ray, soft X-ray (SXR) or extreme ultraviolet radiation (EUV)) so as to generate first scattered radiation; a final focusing element (815) (e.g., a first grating) being configured to: collect at least a portion of the first scattered radiation, the collected first scattered radiation comprising a plurality of first scattered beams (e.g., of different diffraction orders (m=-1, m=0, m=+1)), each having been scattered in a respective different direction; and focus the collected first scattered radiation on a second dispersive element (e.g., a target being measured, such as a second (target) grating) (820) such that each of the first scattered beams is incident on the second dispersive element (820) at a respective different angle of incidence; and at least one detector (825) operable to detect second scattered radiation (e.g., of different diffraction orders (-1,+1; -1,0; 0,0; +1,-1; +1,0)) having been scattered by the second dispersive element (820). At least one pair of second scattered beams comprised within the second scattered radiation may overlap on the detector (825) to form interference fringes, wherein the metrology tool may be configured to determine a phase difference between the beams of each pair of second scattered beams from the position of respective interference fringes on the detector (825) for each pair of second scattered beams. The metrology tool may comprise a first focusing element (805) being operable to focus the source radiation at an intermediate field plane, wherein the first dispersive element (810) is located at the intermediate field plane or wherein the first dispersive element (810) is located at a defocus distance (dZ) from the intermediate field plane (IFP). Alternatively, the first dispersive element may comprise a virtual first dispersive element (1010) located at a source plane, wherein a radiation source for generating the source radiation may comprise a laser source arrangement operable to generate a pair of radiation beams (laser pulses) (1000a, 1000b) towards a gas target such that the pair of radiation beams (1000a, 1000b) overlaps temporally and spatially and at respective different angles in the gas target so as to generate an interference pattern forming the virtual first dispersive element (1010), wherein a rotatable waveplate (1050) may be provided in the path of at least one radiation beam (1000b) of the pair of radiation beams to control polarization and interference of the radiation beams (1000a, 1000b). The final focusing element (815) may comprise a final focusing mirror element, wherein the final focusing mirror element may comprise a hollow prolate spheroid portion (1100), having a reflective internal surface (1110). The metrology tool is configured to measure a parameter of interest during manufacturing process at multiple angles of incidence simultaneously.

Anmelder

Firma

ASML Netherlands B.V.

Land

🇳🇱 Niederlande

Fachgebiete