Patent ID: 11860544
Assignee: TAIWAN SEMICONDUCTOR MANUFACTURING COMPANY LTD.
Field: Optics (Instruments)
Classification: CPC G  H | IPC G  H

Claim 12:
13. An apparatus for extreme ultraviolet (EUV) lithography, comprising:
a droplet generator configured to generate target droplets;
an EUV radiation source for generating EUV radiation including an excitation radiation source, excitation radiation from the excitation radiation source interacting with the target droplets;
a system of mirrors for guiding the EUV radiation after interaction with the target droplets; and
a final focus module that receives the EUV radiation after interaction with the target droplets from the system of mirrors and is configured to:
determine aberration of the EUV radiation that is received;
generate a plurality of Zernike polynomials;
determine one or more Zernike polynomials from the plurality of Zernike polynomials that correspond to the aberration;
determine a shift in at least one of Zernike coefficients of the one or more Zernike polynomials; and
reduce the shift by controlling one or more mirrors in the system of mirrors to change a trajectory of the excitation radiation prior to interacting with the target droplets.