Scatterometry structure with embedded ring oscillator, and methods of using same

• US 6,791,697 B1
• Filed: 03/21/2002
• Issued: 09/14/2004
• Est. Priority Date: 03/21/2002
• Status: Active Grant

• Current Assignee: Taiwan Semiconductor Manufacturing Company Limited
• Original Assignee: Advanced Micro Devices, Inc.
• Inventors: Nariman, Homi E.
• Primary Examiner(s): NGUYEN, MINH T
• Application Number:
  US10/104,675
• Time in Patent Office: 908 Days
• Field of Search: 438/14-18, 331/57, 331/44, 331/64, 356/600-608, 356/625-629, 356/392, 356/394, 356/610-613
• US Class Current: 356/603
• CPC Class Codes: G01R 31/2656 using non-ionising electromagnetic radiation, e.g. optical radiation
• CPC Class Codes: H01L 22/34 Circuits for electrically characterising or monitoring manufacturing processes, e. g. whole test die, wafers filled with test structures, on-board-devices incorporated on each die, process control monitors or pad structures thereof, devices in scribe line switching, multiplexing, gating devices G01R19/25; process control with lithography, e.g. dose control, G03F7/20; structures for alignment control by optical means G03F7/70633
• CPC Class Codes: H01L 2924/00 Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
• CPC Class Codes: H01L 2924/0002 Not covered by any one of groups H01L24/00, H01L24/00 and H01L2224/00

Abstract

In one illustrative embodiment, the method involves forming a ring oscillator that includes a first grating structure comprised of a plurality of gate electrode structures for a plurality of N-channel transistors and a second grating structure comprised of a plurality of gate electrode structures for a plurality of P-channel transistors, and measuring the critical dimension and/or profile of at least one of the gate electrode structures in the first grating structure and/or the second grating structure using a scatterometry tool. In another embodiment, the method further involves forming at least one capacitance loading structure, comprised of a plurality of features, as a portion of the ring oscillator, and measuring the critical dimension and/or profile of at least one of the features of the capacitance loading structure using a scatterometry tool.

Claims

1. A method, comprising:

forming a ring oscillator that comprises a first grating structure comprised of a plurality gate electrode structures for a plurality of N-channel transistors and a second grating structure comprised of a plurality of gate electrode structures for a plurality of P-channel transistors; and

measuring at least one of a critical dimension and a profile of at least one of said gate electrode structures in at least one of said first grating structure and said second grating structure using a scatterometry tool.

2. The method of claim 1, wherein each of said gate electrode structures in said first grating structure are electrically coupled to a separate gate electrode structure comprising said second grating structure.

3. The method of claim 1, wherein measuring at least one of a critical dimension and a profile of at least one of said gate electrode structures in at least one of said first grating structure and said second grating structure using a scatterometry tool comprises illuminating at least one of said first and second grating structures and measuring light reflected off of said at least one of said first and second grating structures.

4. The method of claim 1, wherein said first grating structure is comprised of 101 gate electrode structures and wherein said second grating structure is comprised of 101 gate electrode structures.

5. The method of claim 1, further comprising comparing said measured at least one of a critical dimension and a profile of said at least one of said gate electrode structures to a model to predict at least one electrical performance characteristic of said ring oscillator.

6. The method of claim 5, wherein said at least one electrical performance characteristic is comprised of at least one of a drive current and an operating frequency of said ring oscillator.

7. The method of claim 1, further comprising comparing said measured at least one of a critical dimension and a profile of said at least one of said gate electrode structures to a model to predict at least one electrical performance characteristic of said ring oscillator, said model correlating at least one of a critical dimension and a profile of a gate electrode structure to at least one electrical performance characteristic of said ring oscillator.

8. The method of claim 1, further comprising:

forming at least one capacitance loading structure comprised of a plurality of features, said at least one capacitance loading structure being a portion of said ring oscillator; and

measuring at least one of a critical dimension and a profile of at least one of said features in said capacitance loading structure using a scatterometry tool.

9. The method of claim 8, further comprising comparing said measured at least one of a critical dimension and a profile of at least one of said features in said capacitance loading structure to a model to predict at least one electrical performance characteristic of said ring oscillator.

10. The method of claim 8, further comprising comparing said measured at least one of a critical dimension and a profile of said at least one of said features in said capacitance loading structure to a model to predict at least one electrical performance characteristic of said ring oscillator, said model correlating at least one of a critical dimension and a profile of a feature in said capacitance loading structure to at least one electrical performance characteristic of said ring oscillator.

11. The method of claim 10, wherein said at least one electrical performance characteristic is comprised of at least one of a drive current and an operating frequency of said ring oscillator.

12. The method of claim 8, wherein measuring at least one of a critical dimension and a profile of at least one of said features in said capacitance loading structure using a scatterometry tool comprises illuminating said features in said capacitance loading structure and measuring light reflected off of said features.

13. The method of claim 8, wherein said capacitance loading structure is comprised of a plurality of line-type features.

14. A method, comprising:

forming a ring oscillator that comprises a first grating structure comprised of a plurality gate electrode structures for a plurality of N-channel transistors and a second grating structure comprised of a plurality of gate electrode structures for a plurality of P-channel transistors;

measuring at least one of a critical dimension and a profile of at least one of said gate electrode structures in at least one of said first grating structure and said second grating structure using a scatterometry tool; and

comparing said measured at least one of a critical dimension and a profile of said at least one of said gate electrode structures to a model to predict at least one electrical performance characteristic of said ring oscillator, said model correlating at least one of a critical dimension and a profile of a gate electrode structure to at least one electrical performance characteristic of said ring oscillator.

15. The method of claim 14, wherein each of said gate electrode structures in said first grating structure are electrically coupled to a separate gate electrode structure in said second grating structure.

16. The method of claim 14, wherein measuring at least one of a critical dimension and a profile of at least one of said gate electrode structures in at least one of said first grating structure and said second grating structure using a scatterometry tool comprises illuminating at least one of said first and second grating structures and measuring light reflected off of said at least one of said first and second grating structures.

17. The method of claim 14, wherein said first grating structure is comprised of 101 gate electrode structures and wherein said second grating structure is comprised of 101 gate electrode structures.

18. The method of claim 14, wherein said at least one electrical performance characteristic is comprised of at least one of a drive current and an operating frequency of said ring oscillator.

19. The method of claim 14, further comprising:

forming at least one capacitance loading structure comprised of a plurality of features, said at least one capacitance loading structure being a portion of said ring oscillator; and

measuring at least one of a critical dimension and a profile of at least one of said features in said capacitance loading structure using a scatterometry tool.

20. The method of claim 19, further comprising comparing said measured at least one of a critical dimension and a profile of at least one of said features in said capacitance loading structure to a model to predict at least one electrical performance characteristic of said ring oscillator.

21. The method of claim 20, wherein said at least one electrical performance characteristic is comprised of at least one of a drive current and an operating frequency of said ring oscillator.

22. The method of claim 19, further comprising comparing said measured at least one of a critical dimension and a profile of said at least one of said features in said capacitance loading structure to a model to predict at least one electrical performance characteristic of said ring oscillator, said model correlating at least one of a critical dimension and a profile of a feature in said capacitance loading structure to said at least one electrical performance characteristic of said ring oscillator.

23. The method of claim 19, wherein measuring at least one of a critical dimension and a profile of at least one of said features in said capacitance loading structure using a scatterometry tool comprises illuminating said features in said capacitance loading structure and measuring light reflected off of said features.

24. The method of claim 19, wherein said capacitance loading structure is comprised of a plurality of line-type features.

25. A method, comprising:

forming a ring oscillator that comprises a first grating structure comprised of a plurality gate electrode structures for a plurality of N-channel transistors and a second grating structure comprised of a plurality of gate electrode structures for a plurality of P-channel transistors;

measuring at least one of a critical dimension and a profile of at least one of said gate electrode structures in at least one of said first grating structure and said second grating structure using a scatterometry tool;

forming at least one capacitance loading structure comprised of a plurality of features, said at least one capacitance loading structure being a portion of said ring oscillator; and

measuring at least one of a critical dimension and a profile of at least one of said features in said capacitance loading structure using a scatterometry tool.

26. The method of claim 25, wherein each of said gate electrode structures in said first grating structure are electrically coupled to a separate gate electrode structure in said second grating structure.

27. The method of claim 25, wherein measuring at least one of a critical dimension and a profile of at least one of said gate electrode structures in at least one of said first grating structure and said second grating structure using a scatterometry tool comprises illuminating at least one of said first and second grating structures and measuring light reflected off of said at least one of said first and second grating structures.

28. The method of claim 25, wherein said first grating structure is comprised of 101 gate electrode structures and wherein said second grating structure is comprised of 101 gate electrode structures.

29. The method of claim 25, further comprising comparing said measured at least one of a critical dimension and a profile of said at least one of said gate electrode structures to a model to predict at least one electrical performance characteristic of said ring oscillator.

30. The method of claim 29, wherein said at least one electrical performance characteristic is comprised of at least one of a drive current and an operating frequency of said ring oscillator.

31. The method of claim 25, further comprising comparing said measured at least one of a critical dimension and a profile of said at least one of said gate electrode structures to a model to predict at least one electrical performance characteristic of said ring oscillator, said model correlating at least one of a critical dimension and a profile of a gate electrode structure to at least one electrical performance characteristic of said ring oscillator.

32. The method of claim 25, further comprising comparing said measured at least one of a critical dimension and a profile of at least one of said features in said capacitance loading structure to a model to predict at least one electrical performance characteristic of said ring oscillator.

33. The method of claim 25, further comprising comparing said measured at least one of a critical dimension and a profile of said at least one of said features in said capacitance loading structure to a model to predict at least one electrical performance characteristic of said ring oscillator, said model correlating at least one of a critical dimension and a profile of a feature comprising said capacitance loading structure to at least one electrical performance characteristic of said ring oscillator.

34. The method of claim 33, wherein said at least one electrical performance characteristic is comprised of at least one of a drive current and an operating frequency of said ring oscillator.

35. The method of claim 25, wherein measuring at least one of a critical dimension and a profile of at least one of said features in said capacitance loading structure using a scatterometry tool comprises illuminating said features in said capacitance loading structure and measuring light reflected off of said features.

36. The method of claim 25, wherein said capacitance loading structure is comprised of a plurality of line-type features.

37. A method, comprising:

forming a ring oscillator that comprises a first grating structure comprised of a plurality gate electrode structures for a plurality of N-channel transistors and a second grating structure comprised of a plurality of gate electrode structures for a plurality of P-channel transistors;

measuring at least one of a critical dimension and a profile of at least one of said gate electrode structures in at least one of said first grating structure and said second grating structure using a scatterometry tool;

forming at least one capacitance loading structure comprised of a plurality of features, said at least one capacitance loading structure being a portion of said ring oscillator;

measuring at least one of a critical dimension and a profile of at least one of said features in said capacitance loading structure using a scatterometry tool;

comparing said measured at least one of a critical dimension and a profile of said at least one of said gate electrode structures to a model to predict at least one electrical performance characteristic of said ring oscillator; and

comparing said measured at least one of a critical dimension and a profile of at least one of said features in said capacitance loading structure to a said model to predict at least one electrical performance characteristic of said ring oscillator.

38. The method of claim 37, wherein each of said gate electrode structures in said first grating structure are electrically coupled to a separate gate electrode structure in said second grating structure.

39. The method of claim 37, wherein measuring at least one of a critical dimension and a profile of at least one of said gate electrode structures in at least one of said first grating structure and said second grating structure using a scatterometry tool comprises illuminating at least one of said first and second grating structures and measuring light reflected off of at least one of said first and second grating structures.

40. The method of claim 37, wherein said first grating structure is comprised of 101 gate electrode structures and wherein said second grating structure is comprised of 101 gate electrode structures.

41. The method of claim 37, wherein said at least one electrical performance characteristic is comprised of at least one of a drive current and an operating frequency of said ring oscillator.

42. The method of claim 37, wherein said model provides a correlation between at least one of a critical dimension and a profile of a gate electrode structure to at least one electrical performance characteristic of said ring oscillator.

43. The method of claim 37, wherein said model further provides a correlation between at least one of a critical dimension and a profile of a feature comprising said capacitance loading structure to at least one electrical performance characteristic of said ring oscillator.

44. The method of claim 37, wherein measuring at least one of a critical dimension and a profile of at least one of said features in said capacitance loading structure a scatterometry tool comprises illuminating said features in said capacitance loading structure and measuring light reflected off of said features.

45. The method of claim 37, wherein said capacitance loading structure is comprised of a plurality of line-type features.