Time-domain computation of scattering spectra for use in spectroscopic metrology
AssigneeKLA-Tencor Corporation
InventorsEdward Ratner, Andrei Veldman, Daniel Wack
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Abstract
In an embodiment, a method of time-domain simulation for simulating scattering spectra is described. The method may provide for computing spatial derivatives including computing spectral derivatives in some portion of the domain and finite difference derivatives in some other portion of the domain; forming an equation for non-reflecting boundary conditions; and computing a time-stepping scheme using a high-order unconditionally stable computation method.
Claims28
A method of time-domain computation for simulating electromagnetic (EM) scattering spectra comprising:
- a processor computing spatial derivatives comprising computing spectral derivatives in some portion of the domain and finite difference derivatives in some other portion of the domain;
- the processor forming an equation for boundary conditions;
- and
- the processor computing a time-stepping scheme.
A method of time-domain computation for simulating electromagnetic (EM) scattering spectra comprising:
- a processor computing spatial derivatives of the domain;
- the processor forming an equation for non-reflecting boundary conditions to truncate the computational domain;
- and
- the processor computing a time-stepping scheme.
A method of time-domain computation for simulating electromagnetic (EM) scattering spectra comprising:
- a processor computing spatial derivatives of the domain;
- the processor forming an equation for boundary conditions;
- and
- the processor computing a time-stepping scheme using a high-order unconditionally stable computation method.
A system for measuring electromagnetic (EM) spectra and computing a time-domain simulation for simulating scattering spectra comprising:
- a broadband EM radiation source for illuminating a wafer;
- a spectrometer to detect different spectral components of radiation reflected from the wafer;
- and
- a processor to compute scattering spectra by:
- computing spatial derivatives comprising computing spectral derivatives in some portion of the domain and finite difference derivatives in some other portion of the domain;
- forming an equation for non-reflecting boundary conditions;
- computing a high-order unconditionally stable computation method;
- varying the model geometry;
- and
- re-computing the computed scattering spectra until the computed scatting spectra matches a measured spectrum.
Dependencies are inferred from the claim text.