Apparatus for angular-resolved spectroscopic lithography characterization
To inspect all portions of the substrate the substrate table can be moved rotationally and linearly. Furthermore the detector can be moved rotationally. This enables all portions of a surface of the substrate to be inspected from all angles in a plane parallel to the substrate. Less linear motion is needed, so the apparatus occupies a smaller volume and generates smaller vibrations.
1. A scatterometer, comprising:
a radiation projector configured to project radiation;
a lens configured to focus radiation;
a substrate table arranged to hold a substrate such that a surface of the substrate is exposed by the focused radiation, wherein the substrate table is configured to be moved linearly along a first axis and rotationally about a second axis perpendicular to the first axis;
a detector configured to detect an angled resolved spectrum reflected from the substrate; and
a rotor coupled to the detector and configured to rotate the detector about the second axis.
2. The scatterometer of claim 1 , wherein the substrate table is mounted on a stage configured to move linearly on a third axis parallel to the surface of the substrate, the substrate table rotating relative to the stage.
3. The scatterometer of claim 2 , wherein the stage is mounted on a mount, the stage being configured to move linearly with respect to the mount.
4. The scatterometer of claim 1 , wherein the detector is mounted on a mount and the rotor is configured to rotate the detector relative to the mount.
5. The scatterometer of claim 1 , further comprising a motor configured to move the substrate table linearly.
6. The scatterometer of claim 1 , further comprising a motor configured to rotate the substrate table.
7. The scatterometer of claim 1 , further comprising a motor that includes the rotor.
8. The scatterometer of claim 1 , further comprising bearings configured to support the substrate table.
9. The scatterometer of claim 8 , wherein the bearings are air bearings.
10. The scatterometer of claim 1 , further comprising bearings configured to support the detector.
11. The scatterometer of claim 10 , wherein the bearings are air bearings.
12. The scatterometer of claim 1 , wherein the lens is a high numerical aperture lens.
13. The scatterometer of claim 12 , wherein the numerical aperture is at least 0.9.
14. A lithographic apparatus comprising a scatterometer, the scatterometer comprising:
a radiation projector configured to project radiation;
a lens configured to focus the radiation;
a substrate table arranged to hold a substrate such that a surface of the substrate is exposed by the focused radiation, wherein the substrate table is configured to be moved linearly along a first axis and rotationally about a second axis perpendicular to the first axis;
a detector configured to detect an angled resolved spectrum reflected from the substrate; and
a rotor coupled to the detector and configured to rotate the detector about the second axis.
15. The apparatus of claim 14 , wherein the substrate table is mounted on a stage configured to move linearly on a third axis parallel to the surface of the substrate, the substrate table rotating relative to the stage.
16. The apparatus of claim 15 , wherein the stage is mounted on a mount, the stage being configured to move linearly with respect to the mount.
17. The apparatus of claim 14 , wherein the detector is mounted on a mount and the rotor is configured to rotate the detector relative to the mount.
18. The apparatus of claim 14 , further comprising a motor configured to move the substrate table linearly.
19. The apparatus of claim 14 , further comprising a motor configured to rotate the substrate table.
20. The apparatus of claim 14 , further comprising a motor that includes the rotor.
21. The apparatus of claim 14 , further comprising bearings configured to support the substrate table.
22. The apparatus of claim 21 , wherein the bearings are air bearings.
23. The apparatus of claim 14 , further comprising bearings configured to support the detector.
24. The apparatus of claim 23 , wherein the bearings are air bearings.
25. The apparatus of claim 14 , wherein the lens is a high numerical aperture lens.
26. The apparatus of claim 25 , wherein the numerical aperture is at least 0.9.