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

Claim 17:
18. A non-transitory, computer-readable medium comprising computer readable instructions stored in a memory which, when executed by a processor of a computer direct the computer to control a final focus module of an extreme ultraviolet (EUV) lithography apparatus to perform a method, the method comprising:
detecting excitation radiation reflected by a target droplet;
determining aberration of the detected excitation radiation;
generating a plurality of Zernike polynomials;
determining one or more Zernike polynomials from the plurality of Zernike polynomials that correspond to the aberration;
determining a shift in at least one of Zernike coefficients of the one or more Zernike polynomials;
detecting a change in a beam profile of the excitation radiation based on the shift in the Zernike coefficients; and
generating a control signal to adjust a trajectory of an excitation radiation prior to interacting with the target droplet based on the change in the beam profile.