Methods of calibrating and controlling stepper exposure processes and tools, and system for accomplishing same

• US 6,972,853 B1
• Filed: 09/27/2002
• Issued: 12/06/2005
• Est. Priority Date: 09/27/2002
• Status: Active Grant

• Current Assignee: Advanced Micro Devices, Inc.
• Original Assignee: Advanced Micro Devices, Inc.
• Inventors: Stirton, James Broc, Nariman, Homi E.
• Primary Examiner(s): Pham, Hoa Q.
• Assistant Examiner(s): Nguyen, Sang H.
• Application Number:
  US10/259,044
• Time in Patent Office: 1,166 Days
• Field of Search: 356603-604, 356606-610, 356/620, 356630-636, 356392-394, 250/559.09, 250/559.16, 250/559.45, 250/225, 438 5- 18, 438/695, 430/30
• US Class Current: 356/630
• CPC Class Codes: G01N 21/47 Scattering, i.e. diffuse reflection G01N21/25, G01N21/41 take precedence G01N21/55 takes precedence
• CPC Class Codes: G01N 21/9501 Semiconductor wafers manufacturing processes per se of semiconductor devices implementing a measuring step H01L22/10
• CPC Class Codes: G01N 21/956 Inspecting patterns on the surface of objects contactless testing of electronic circuits G01R31/308; testing currency G07D; manufacturing processes per se of semiconductor devices implementing a measuring step H01L22/10
• CPC Class Codes: G03F 7/70483 Information management; Active and passive control; Testing; Wafer monitoring, e.g. pattern monitoring
• CPC Class Codes: G03F 7/70533 Controlling abnormal operating mode, e.g. taking account of waiting time, decision to rework or rework flow
• CPC Class Codes: G03F 7/70625 Dimensions, e.g. line width, critical dimension [CD], profile, sidewall angle or edge roughness
• CPC Class Codes: H01L 22/12 for structural parameters, e.g. thickness, line width, refractive index, temperature, warp, bond strength, defects, optical inspection, electrical measurement of structural dimensions, metallurgic measurement of diffusions electrical measurement of diffusions H01L22/14

Abstract

The present invention is generally directed to various methods of stepper exposure processes and tools, and system for accomplishing same. In one embodiment, the method comprises forming a grating structure comprised of a plurality of photoresist features above a semiconducting substrate, measuring at least one characteristic of at least one of the photoresist features at a plurality of locations within the grating structure, and determining if the measured characteristic of the photoresist features varies across the grating structure.

Claims

1. A method, comprising:

forming a grating structure comprised of a plurality of photoresist features above a semiconducting substrate;

measuring at least one characteristic of at least one of said photoresist features at a plurality of locations within said grating structure; and

determining if said measured characteristic of said photoresist features varies from a first edge of said grating structure to a second edge of said grating structure.

2. The method of claim 1, wherein forming said grating structure comprised of a plurality of photoresist features comprises forming said grating structure comprised of a plurality of line-type photoresist features.

3. The method of claim 1, wherein said semiconducting substrate is comprised of silicon.

4. The method of claim 1, wherein measuring at least one characteristic of at least one of said plurality of photoresist features comprises measuring at least one of a critical dimension, a cross-sectional profile, and a sidewall angle of at least one of said plurality of photoresist features.

5. The method of claim 1, further comprising determining if said measured characteristic of said photoresist features varies from an edge region of said grating structure to a center region of said grating structure.

6. The method of claim 1, further comprising indicating an error condition exists in a stepper exposure tool used in forming said plurality of photoresist features.

7. The method of claim 1, further comprising indicating an error condition exists in a stepper exposure tool used in forming said plurality of photoresist features if said determined variance exceeds a preselected limit.

8. The method of claim 1, further comprising indicating an error condition exists in a stepper exposure tool used in forming said plurality of photoresist features if said determined variance is not within acceptable limits.

9. The method of claim 1, further comprising adjusting at least one parameter of a stepper exposure process to be performed on a subsequently processed substrate if said determined variance is not within acceptable limits.

10. The method of claim 9, wherein adjusting at least one parameter of a stepper exposure process comprises adjusting at least one of a focal plane location, a position of said substrate, a tilt of said substrate and an intensity of a light source.

11. The method of claim 1, further comprising limiting use of a stepper exposure tool used to form said photoresist features if said determined variance exceeds a preselected allowable limit.

12. The method of claim 11, wherein limiting the use of said stepper exposure tool comprises prohibiting the use of said stepper exposure tool in certain situations.

13. The method of claim 1, wherein forming said grating structure comprised of a plurality of photoresist features above said semiconducting substrate comprises forming a plurality of grating structures above said semiconducting substrate, each of said grating structures being comprised of a plurality of photoresist features.

14. The method of claim 13, further comprising measuring at least one characteristic of at least one of said photoresist features at a plurality of locations within each of said plurality of grating structures.

15. A method, comprising:

forming a grating structure comprised of a plurality of photoresist features above a semiconducting substrate;

measuring at least one characteristic of at least one of said photoresist features at a plurality of locations within said grating structure;

determining if said measured characteristic of said photoresist features varies from a first edge of said grating structure to a second edge of said grating structure; and

indicating an error condition exists in a stepper exposure tool used in forming said plurality of photoresist features if said determined variance is not within acceptable limits.

16. The method of claim 15, wherein forming said grating structure comprised of a plurality of photoresist features comprises forming said grating structure comprised of a plurality of line-type photoresist features.

17. The method of claim 15, wherein said semiconducting substrate is comprised of silicon.

18. The method of claim 15, wherein measuring at least one characteristic of at least one of said plurality of photoresist features comprises measuring at least one of a critical dimension, a cross-sectional profile, and a sidewall angle of at least one of said plurality of photoresist features.

19. The method of claim 15, further comprising determining if said measured characteristic of said photoresist features varies from an edge region of said grating structure to a center region of said grating structure.

20. The method of claim 15, further comprising adjusting at least one parameter of a stepper exposure process to be performed on a subsequently processed substrate if said determined variance is not within acceptable limits.

21. The method of claim 20, wherein adjusting at least one parameter of a stepper exposure process comprises adjusting at least one of a focal plane location, a position of said substrate, a tilt of said substrate and an intensity of a light source.

22. The method of claim 15, further comprising limiting use of a stepper exposure tool used to form said photoresist features if said determined variance is not within allowable limits.

23. The method of claim 22, wherein limiting the use of said stepper exposure tool comprises prohibiting the use of said stepper exposure tool in certain situations.

24. The method of claim 15, wherein forming said grating structure comprised of a plurality of photoresist features above said semiconducting substrate comprises forming a plurality of grating structures above said semiconducting substrate, each of said grating structures being comprised of a plurality of photoresist features.

25. The method of claim 24, further comprising measuring at least one characteristic of at least one of said photoresist features at a plurality of locations within each of said plurality of grating structures.

26. A method, comprising:

forming a grating structure comprised of a plurality of photoresist features above a semiconducting substrate;

measuring at least one characteristic of at least one of said photoresist features at a plurality of locations within said grating structure;

determining if said measured characteristic of said photoresist features varies from a first edge of said grating structure to a second edge of said grating structure; and

adjusting at least one parameter of a stepper exposure process to be performed on a subsequently processed substrate if said determined variance is not within acceptable limits.

27. The method of claim 26, wherein forming said grating structure comprised of a plurality of photoresist features comprises forming said grating structure comprised of a plurality of line-type photoresist features.

28. The method of claim 26, wherein said semiconducting substrate is comprised of silicon.

29. The method of claim 26, wherein measuring at least one characteristic of at least one of said plurality of photoresist features comprises measuring at least one of a critical dimension, a cross-sectional profile, and a sidewall angle of at least one of said plurality of photoresist features.

30. The method of claim 26, further comprising determining if said measured characteristic of said photoresist features varies from an edge region of said grating structure to a center region of said grating structure.

31. The method of claim 26, further comprising indicating an error condition exists in a stepper exposure tool used in forming said plurality of photoresist features if said determined variance is not within acceptable limits.

32. The method of claim 26, wherein adjusting at least one parameter of a stepper exposure process comprises adjusting at least one of a focal plane location, a position of said substrate, a tilt of said substrate and an intensity of a light source.

33. The method of claim 26, wherein forming said grating structure comprised of a plurality of photoresist features above said semiconducting substrate comprises forming a plurality of grating structures above said semiconducting substrate, each of said grating structures being comprised of a plurality of photoresist features.

34. The method of claim 33, wherein limiting the use of said stepper exposure tool comprises prohibiting the use of said stepper exposure tool in certain situations.

35. The method of claim 26, further comprising limiting use of a stepper exposure tool used to form said photoresist features if said determined variance exceeds a preselected allowable limit.

36. The method of claim 35, further comprising measuring at least one characteristic of at least one of said photoresist features at a plurality of locations within each of said plurality of grating structures.

37. A method, comprising:

forming a grating structure comprised of a plurality of photoresist features above a semiconducting substrate;

measuring at least one characteristic of at least one of said photoresist features at a plurality of locations within said grating structure;

determining if said measured characteristic of said photoresist features varies from a first edge of said grating structure to a second edge of said grating structure; and

limiting use of a stepper exposure tool used to form said photoresist features if said determined variance exceeds a preselected allowable limit.

38. The method of claim 37, wherein forming said grating structure comprised of a plurality of photoresist features comprises forming said grating structure comprised of a plurality of line-type photoresist features.

39. The method of claim 37, wherein said semiconducting substrate is comprised of silicon.

40. The method of claim 37, wherein measuring at least one characteristic of at least one of said plurality of photoresist features comprises measuring at least one of a critical dimension, a cross-sectional profile, and a sidewall angle of at least one of said plurality of photoresist features.

41. The method of claim 37, further comprising determining if said measured characteristic of said photoresist features varies from an edge region of said grating structure to a center region of said grating structure.

42. The method of claim 37, further comprising indicating an error condition exists in a stepper exposure tool used in forming said plurality of photoresist features if said determined variance is not within acceptable limits.

43. The method of claim 37, further comprising adjusting at least one parameter of a stepper exposure process to be performed on a subsequently processed substrate if said determined variance is not within acceptable limits.

44. The method of claim 43, wherein adjusting at least one parameter of a stepper exposure process comprises adjusting at least one of a focal plane location, a position of said substrate, a tilt of said substrate and an intensity of a light source.

45. The method of claim 37, wherein limiting the use of said stepper exposure tool comprises prohibiting the use of said stepper exposure tool in certain situations.

46. The method of claim 37, wherein forming said grating structure comprised of a plurality of photoresist features above said semiconducting substrate comprises forming a plurality of grating structures above said semiconducting substrate, each of said grating structures being comprised of a plurality of photoresist features.

47. The method of claim 46, further comprising measuring at least one characteristic of at least one of said photoresist features at a plurality of locations within each of said plurality of grating structures.

48. A method, comprising:

forming a grating structure comprised of a plurality of photoresist features above a semiconducting substrate;

measuring at least one characteristic of at least one of said photoresist features at a plurality of locations within said grating structure; and

determining if said measured characteristic of said photoresist features varies from an edge region of said grating structure to a center region of said grating structure.

49. A method, comprising:

forming a grating structure comprised of a plurality of photoresist features above a semiconducting substrate;

measuring at least one characteristic of at least one of said photoresist features at a plurality of locations within said grating structure;

determining if said measured characteristic of said photoresist features varies from an edge region of said grating structure to a center region of said grating structure; and

indicating an error condition exists in a stepper exposure tool used in forming said plurality of photoresist features if said determined variance is not within acceptable limits.

50. A method, comprising:

forming a grating structure comprised of a plurality of photoresist features above a semiconducting substrate;

measuring at least one characteristic of at least one of said photoresist features at a plurality of locations within said grating structure;

determining if said measured characteristic of said photoresist features varies from an edge region of said grating structure to a center region of said grating structure; and

adjusting at least one parameter of a stepper exposure process to be performed on a subsequently processed substrate if said determined variance is not within acceptable limits.

51. A method, comprising:

forming a grating structure comprised of a plurality of photoresist features above a semiconducting substrate;

measuring at least one characteristic of at least one of said photoresist features at a plurality of locations within said grating structure;

determining if said measured characteristic of said photoresist features varies from an edge region of said grating structure to a center region of said grating structure; and

limiting use of a stepper exposure tool used to form said photoresist features if said determined variance exceeds a preselected allowable limit.