Measurement of critical dimensions of nanostructures using X-ray grazing incidence in-plane diffraction
The manufactured structure is illuminated with an x-ray beam. The manufactured structure is positioned at a selected grazing angle and a selected rotation angle with respect to the x-ray beam. The selected rotation angle has been selected to enhance in-plane diffraction of reflections of the x-ray beam by the manufactured structure. A grazing in-plane diffraction beam produced by interference with the periodic feature is detected. A property of the grazing in-plane diffraction beam is determined by the critical dimension.
1. A system for analyzing a manufactured structure having a periodic feature characterized by a critical dimension including:
a x-ray beam source configured to illuminate the manufactured structure with an x-ray beam, wherein the manufactured structure is positioned at a selected grazing angle and a selected rotation angle with respect to the x-ray beam and the selected rotation angle has been selected to enhance in-plane diffraction of reflections of the x-ray beam by the manufactured structure;
a detector configured to detect a grazing in-plane diffraction beam produced by interference with the periodic feature, wherein a property of the grazing in-plane diffraction beam is determined by the critical dimension; and
a processor configured to characterize the critical dimension based on the property of the grazing in-plane diffraction beam.
2. The system of claim 1 , wherein the system is utilized inline in a semiconductor manufacturing process to detect deviation of the manufactured structure from a reference.
3. The system of claim 1 , wherein the manufactured structure is at least a portion of a semiconductor device.
4. The system of claim 1 , wherein the x-ray beam illuminating the manufactured structure has been collimated.
5. The system of claim 1 , wherein the x-ray beam illuminating the manufactured structure has not been collimated.
6. The system of claim 1 , wherein divergent rays of the x-ray beam illuminating the manufactured structure have been focused on the manufactured structure.
7. The system of claim 1 , wherein the x-ray beam illuminating the manufactured structure has a divergence greater than 3 milliradians.
8. The system of claim 1 , wherein characterizing the critical dimension includes determining a measurement value of structure parameters of the critical dimension.
9. The system of claim 1 , wherein characterizing the critical dimension includes comparing the property of the grazing in-plane diffraction beam with a model generated property of an expected grazing in-plane diffraction beam.
10. The system of claim 9 , wherein the model generated property of the expected grazing in-plane diffraction beam was generated using a Parratt analytical model.
11. The system of claim 1 , wherein the selected rotation angle includes an in-plane rotation angle in a plane of the manufactured structure and the in-plane rotation angle has been selected to enhance a diffraction pattern produced by the grazing in-plane diffraction beam when in-plane reflected x-ray paths are superposed.
12. The system of claim 1 , wherein the detector is a two-dimensional detector including scintillator-coupled CCDs.
13. The system of claim 1 , wherein detecting the grazing in-plane diffraction beam includes detecting a diffraction pattern caused at least in part by multiple reflections of a single ray on multiple surfaces of the periodic feature.
14. The system of claim 1 , wherein detecting the grazing in-plane diffraction beam includes detecting a Laue-Bragg diffraction.
15. The system of claim 1 , wherein the property of the grazing in-plane diffraction beam includes one or more of the following: an intensity, an angle, and a position.
16. The system of claim 1 , wherein the critical dimension includes one or more of the following: a sidewall angle, a line height, a linewidth, a pitch, and a roughness.
17. The system of claim 1 , wherein characterizing the critical dimension includes aggregating properties of grazing in-plane diffraction beams detected at different measurement instances corresponding to different rotation angles.
18. The system of claim 1 , wherein characterizing the critical dimension includes detecting one or more peaks of a plot of the property of the grazing in-plane diffraction beam.
19. A method for analyzing a manufactured structure having a periodic feature characterized by a critical dimension including:
illuminating the manufactured structure with an x-ray beam, wherein the manufactured structure is positioned at a selected grazing angle and a selected rotation angle with respect to the x-ray beam and the selected rotation angle has been selected to enhance in-plane diffraction of reflections of the x-ray beam by the manufactured structure;
detecting a grazing in-plane diffraction beam produced by interference with the periodic feature, wherein a property of the grazing in-plane diffraction beam is determined by the critical dimension; and
characterizing the critical dimension based on the property of the grazing in-plane diffraction beam.
20. The method of claim 19 , wherein characterizing the critical dimension includes detecting a deviation of the manufactured structure from a reference as a part of a semiconductor manufacturing process.
21. The method of claim 19 , wherein the manufactured structure is at least a portion of a semiconductor device.
22. The method of claim 19 , wherein the x-ray beam illuminating the manufactured structure has been collimated.
23. The method of claim 19 , wherein the x-ray beam illuminating the manufactured structure has not been collimated.
24. The method of claim 19 , wherein divergent rays of the x-ray beam illuminating the manufactured structure have been focused on the manufactured structure.
25. The method of claim 19 , wherein the x-ray beam illuminating the manufactured structure has a divergence greater than 3 milliradians.
26. The method of claim 19 , wherein characterizing the critical dimension includes determining a measurement value of structure parameters of the critical dimension.
27. The method of claim 19 , wherein characterizing the critical dimension includes comparing the property of the grazing in-plane diffraction beam with a model generated property of an expected grazing in-plane diffraction beam.
28. The method of claim 27 , wherein the model generated property of the expected grazing in-plane diffraction beam was generated using a Parratt analytical model.
29. The method of claim 19 , wherein the selected rotation angle includes an in-plane rotation angle in a plane of the manufactured structure and the in-plane rotation angle has been selected to enhance a diffraction pattern produced by the grazing in-plane diffraction beam when in-plane reflected x-ray paths are superposed.
30. The method of claim 19 , wherein the grazing in-plane diffraction beam is detected using a two-dimensional detector including scintillator-coupled CCDs.
31. The method of claim 19 , wherein detecting the grazing in-plane diffraction beam includes detecting a diffraction pattern caused at least in part by multiple reflections of a single ray on multiple surfaces of the periodic feature.
32. The method of claim 19 , wherein detecting the grazing in-plane diffraction beam includes detecting a Laue-Bragg diffraction.
33. The method of claim 19 , wherein the property of the grazing in-plane diffraction beam includes one or more of the following: an intensity, an angle, and a position.
34. The method of claim 19 , wherein the critical dimension includes one or more of the following: a sidewall angle, a line height, a linewidth, a pitch, and a roughness.
35. The method of claim 19 , wherein characterizing the critical dimension includes aggregating properties of grazing in-plane diffraction beams detected at different measurement instances corresponding to different rotation angles.
36. The method of claim 19 , wherein characterizing the critical dimension includes detecting one or more peaks of a plot of the property of the grazing in-plane diffraction beam.
37. A computer program product for analyzing a manufactured structure having a periodic feature characterized by a critical dimension, the computer program product being embodied in a tangible computer readable storage medium and comprising computer instructions for:
illuminating the manufactured structure with an x-ray beam, wherein the manufactured structure is positioned at a selected grazing angle and a selected rotation angle with respect to the x-ray beam and the selected rotation angle has been selected to enhance in-plane diffraction of reflections of the x-ray beam by the manufactured structure;
detecting a grazing in-plane diffraction beam produced by interference with the periodic feature, wherein a property of the grazing in-plane diffraction beam is determined by the critical dimension; and
characterizing the critical dimension based on the property of the grazing in-plane diffraction beam.
38. The computer program product of claim 37 , wherein characterizing the critical dimension includes detecting a deviation of the manufactured structure from a reference as a part of a semiconductor manufacturing process.
39. The computer program product of claim 37 , wherein the manufactured structure is at least a portion of a semiconductor device.
40. computer program product of claim 37 , wherein the x-ray beam illuminating the manufactured structure has been collimated.
41. The computer program product of claim 37 , wherein the x-ray beam illuminating the manufactured structure has not been collimated.
42. The computer program product of claim 37 , wherein divergent rays of the x-ray beam illuminating the manufactured structure have been focused on the manufactured structure.
43. The computer program product of claim 37 , wherein the x-ray beam illuminating the manufactured structure has a divergence greater than 3 milliradians.
44. The computer program product of claim 37 , wherein characterizing the critical dimension includes determining a measurement value of structure parameters of the critical dimension.
45. The computer program product of claim 37 , wherein characterizing the critical dimension includes comparing the property of the grazing in-plane diffraction beam with a model generated property of an expected grazing in-plane diffraction beam.
46. The computer program product of claim 45 , wherein the model generated property of the expected grazing in-plane diffraction beam was generated using a Parratt analytical model.
47. The computer program product of claim 37 , wherein the selected rotation angle includes an in-plane rotation angle in a plane of the manufactured structure and the in-plane rotation angle has been selected to enhance a diffraction pattern produced by the grazing in-plane diffraction beam when in-plane reflected x-ray paths are superposed.
48. The computer program product of claim 37 , wherein the grazing in-plane diffraction beam is detected using a two-dimensional detector including scintillator-coupled CCDs.
49. The computer program product of claim 37 , wherein detecting the grazing in-plane diffraction beam includes detecting a diffraction pattern caused at least in part by multiple reflections of a single ray on multiple surfaces of the periodic feature.
50. The computer program product of claim 37 , wherein detecting the grazing in-plane diffraction beam includes detecting a Laue-Bragg diffraction.
51. The computer program product of claim 37 , wherein the property of the grazing in-plane diffraction beam includes one or more of the following: an intensity, an angle, and a position.
52. The computer program product of claim 37 , wherein the critical dimension includes one or more of the following: a sidewall angle, a line height, a linewidth, a pitch, and a roughness.
53. The computer program product of claim 37 , wherein characterizing the critical dimension includes aggregating properties of grazing in-plane diffraction beams detected at different measurement instances corresponding to different rotation angles.
54. The computer program product of claim 37 , wherein characterizing the critical dimension includes detecting one or more peaks of a plot of the property of the grazing in-plane diffraction beam.