Systems having light source with extended spectrum for semiconductor chip surface topography metrology
Embodiments of systems for classifying interference signals are disclosed. In an example, a system for classifying interference signals includes an interferometer including a light source and a detector, and at least one processor. The interferometer is configured to provide a plurality of interference signals each corresponding to a respective one of a plurality of positions on a surface of a semiconductor chip. A spectrum of the light source is greater than a spectrum of white light. The at least one processor is configured to classify the interference signals into a plurality of categories using a model. Each of the categories corresponds to a region having a same material on the surface of the semiconductor chip.
1. A system for classifying interference signals, comprising:
an interferometer comprising a light source and a detector, the interferometer configured to provide a plurality of interference signals each corresponding to a respective one of a plurality of positions on a surface of a semiconductor chip, wherein a spectrum of the light source is greater than a spectrum of white light; and
at least one processor configured to:
cluster the plurality of interference signals into a plurality of clusters using a model; and
adjust the plurality of clusters into a plurality of categories based on a design of the semiconductor chip, wherein the plurality of categories are associated with interference signal classification, and wherein each of the plurality of categories corresponds to a region having a same material on the surface of the semiconductor chip.
2. The system of claim 1 , wherein the spectrum of the light source comprises at least one of ultraviolet (UV) light or infrared (IR) light.
3. The system of claim 1 , wherein a range of wavelengths of the spectrum of the light source is greater than a range between about 400 nm and about 900 nm.
4. The system of claim 3 , wherein the range of wavelengths of the spectrum of the light source is between about 190 nm and about 1,100 nm.
5. The system of claim 1 , wherein the light source comprises a Xenon (Xe) lamp.
6. The system of claim 5 , wherein the detector comprises a white light charge coupled device (CCD) or a white light charge complementary metal oxide semiconductor (CMOS) image sensor.
7. The system of claim 1 , wherein each of the interference signals comprises an interference fringe having a width not greater than about 2 μm.
8. The system of claim 7 , wherein the width of the interference fringe is about 1.2 μm.
9. The system of claim 1 , wherein at least part of the surface of the semiconductor chip comprises a transparent layer.
10. The system of claim 9 , wherein a minimum thickness of the transparent layer is not greater than about 2 μm.
11. The system of claim 1 , wherein the interferometer further comprises an optical element configured to manipulate the spectrum of the light source.
12. The system of claim 11 , wherein the optical element comprises at least one of a filter or an antireflection film.
13. A system for classifying interference signals, comprising:
an interferometer comprising a light source and a detector, the interferometer configured to provide a plurality of interference signals each corresponding to a respective one of a plurality of positions on a surface of a semiconductor chip, wherein each of the interference signals comprises an interference fringe having a width not greater than about 2 μm; and
at least one processor configured to:
cluster the plurality of interference signals into a plurality of clusters using a model; and
adjust the plurality of clusters into a plurality of categories based on a design of the semiconductor chip, wherein the plurality of categories are associated with interference signal classification, and wherein each of the plurality of categories corresponds to a region having a same material on the surface of the semiconductor chip.
14. The system of claim 13 , wherein the width of the interference fringe is about 1.2 μm.
15. The system of claim 13 , wherein a spectrum of the light source is greater than a spectrum of white light.
16. The system of claim 15 , wherein the spectrum of the light source comprises at least one of ultraviolet (UV) light or infrared (IR) light.
17. The system of claim 15 , wherein a range of wavelengths of the spectrum of the light source is greater than a range between about 400 nm and about 900 nm.
18. The system of claim 13 , wherein the light source comprises a Xenon (Xe) lamp.
19. The system of claim 18 , wherein the detector comprises a white light charge coupled device (CCD) or a white light charge complementary metal oxide semiconductor (CMOS) image sensor.
20. A system for classifying spectrum signals, comprising:
an interferometer comprising a light source and a detector, the interferometer configured to provide a plurality of interference signals each corresponding to a respective one of a plurality of positions on a surface of a semiconductor chip, wherein a spectrum of the light source is greater than a spectrum of white light; and
at least one processor configured to:
transform the plurality of interference signals into a plurality of spectrum signals each corresponding to a respective one of the positions on the surface of the semiconductor chip;
cluster the plurality of interference signals into a plurality of clusters using a model; and
adjust the plurality of clusters into a plurality of categories based on a design of the semiconductor chip, wherein the plurality of categories are associated with interference signal classification, and wherein each of the plurality of categories corresponds to a region having a same material on the surface of the semiconductor chip.