Parameterizing x-ray scattering measurement using slice-and-image tomographic imaging of semiconductor structures
Semiconductor structures can be investigated, e.g., in an in-line quality check. An x-ray scattering measurement, e.g., CD-SAXS, can be used for wafer metrology. The x-ray scattering measurement can be configured based on a slice-and-imaging tomographic measurement using a dual-beam device, e.g., including a focused ion beam device and a scanning electron microscope.
1. A method, comprising:
performing a slice-and-image tomographic measurement to obtain one or more three-dimensional volume images of a wafer comprising semiconductor structures;
parameterizing an x-ray scattering measurement based on the one or more three-dimensional volume images; and
after parameterizing the x-ray scattering measurement, performing the x-ray scattering measurement to obtain one or more measurement spectra of the wafer or one or more further wafers comprising the semiconductor structures or further semiconductor structures,
wherein the x-ray scattering measurement is performed in-line of a production line, and the slice-and-image measurement is performed out-of-line of the production line.
2. The method of claim 1 , wherein parameterizing the x-ray scattering measurement comprises determining one or more reference spectra based on a geometry of the semiconductor structures determined based on the one or more three-dimensional volume images.
3. The method of claim 2 , wherein parameterizing the x-ray scattering measurement comprises determining multiple reference spectra based on a variation of the geometry of the semiconductor structure across the one or more three-dimensional volume images.
4. The method of claim 2 , wherein:
the wafer or the one or more further wafers further comprise other semi-conductor structures; and
determining the one or more reference spectra comprises determining a first contribution to the one or more reference spectra associated with the semiconductor structures and determining a second contribution to the one or more reference spectra associated with the other semiconductor structures.
5. The method of claim 2 , wherein:
the x-ray scattering measurement is performed multiple times for multiple test volumes of the wafer or the one or more further wafers; and
the method further comprises:
monitoring a match between the measurement spectra obtained for the multiple test volumes and the one or more reference spectra; and
depending on the monitoring, selectively re-performing the slice-and-image measurement to obtain one or more further three-dimensional volume images of at least one of the multiple test volumes; and
determining the geometry of the semiconductor structures based on the one or more further three-dimensional volume images.
6. The method of claim 5 , further comprising selectively re-parameterizing the x-ray scattering measurement based on the one or more further three-dimensional volume images.
7. The method of claim 1 , wherein parameterizing the x-ray scattering measurement comprises determining an object transfer function of a signal model used to predict one or more reference spectra based on a geometry of the semiconductor structures determined based on the one or more three-dimensional volume images.
8. The method of claim 1 , wherein parameterizing the x-ray scattering measurement comprises setting an imaging parameter of the x-ray scattering measurement.
9. The method of claim 8 , wherein the imaging parameter is set to resolve ambiguities of the one or more measurement spectra between different geometries of the semiconductor structures determined based on the one or more three-dimensional volume images.
10. The method of claim 8 , wherein the imaging parameter comprises at least one member selected from a group consisting of a wavelength of the x-ray radiation, an incidence angle of the x-ray radiation, an acceleration voltage of an x-ray source of the x-ray radiation, a polarization of the x-ray radiation, a diffraction order of the x-ray radiation, a beam shape of the x-ray radiation, and a flux of the x-ray radiation.
11. The method of claim 1 , further comprising, based on the one or more measurement spectra, determining a geometry of the semiconductor structures or the further semiconductor structures.
12. The method of claim 1 , further comprising, based on the one or more measurement spectra, executing the in-line quality check within a production line of a manufacturing process of the semiconductor structures or the further semiconductor structures.
13. The method of claim 12 , wherein the slice-and-image measurement performed out-of-line of the production line is triggered by the in-line quality check.
14. The method of claim 1 , wherein the semiconductor structures comprise deep-etched memory channel holes crossing multiple layers of the wafer.
15. One or more non-transitory machine-readable hardware storage devices comprising instructions that are executable by one or more processing devices to perform operations comprising the method of claim 1 .
16. A system, comprising:
one or more processing devices; and
one or more machine-readable hardware storage devices comprising instructions that are executable by the one or more processing devices to perform operations comprising the method of claim 1 .