Method of measuring implant profiles using scatterometric techniques

• US 6,989,900 B1
• Filed: 04/02/2001
• Issued: 01/24/2006
• Est. Priority Date: 04/02/2001
• Status: Expired due to Fees

• Current Assignee: GlobalFoundries, Inc.
• Original Assignee: Advanced Micro Devices, Inc.
• Inventors: Stirton, James Broc
• Primary Examiner(s): Lauchman, Layla G.
• Assistant Examiner(s): VALENTIN, JUAN D
• Application Number:
  US09/824,156
• Time in Patent Office: 1,758 Days
• Field of Search: 356/445, 356/446, 356/447, 356/448, 438/14, 438/15, 438/16
• US Class Current: 356/445
• 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

Abstract

The present invention is directed to several inventive methods for characterizing implant profiles. In one embodiment, the method comprises forming a first plurality of implant regions in a substrate, and illuminating the implant regions with a light source in a scatterometry tool, the scatterometry tool generating a trace profile corresponding to an implant profile of the illuminated implant regions. In another embodiment, the method comprises measuring profiles of implant regions by forming a plurality of implant regions in a substrate, illuminating the implant regions, measuring light reflected off the substrate to generate a profile trace for the implant regions, comparing the generated profile trace to a target profile trace from a library, and modifying, based upon a deviation between the generated profile trace and the target profile trace, at least one parameter of an ion implant process used to form implant regions on subsequently processed substrates. In yet another embodiment, the generated profile trace is compared or correlated to at least one of a plurality of calculated profile traces stored in a library, each of which has an associated implant region profile, and modifying, based upon the comparison of the generated profile trace and the calculated profile trace, at least one parameter of an ion implant process used to form implant regions on subsequently processed substrates.

Claims

1. A method, comprising:

providing a semiconducting substrate;

forming a first plurality of implant regions in said substrate;

illuminating said first plurality of implant regions with a light source in a scatterometry tool, said scatterometry tool generating a trace profile corresponding to an implant profile of said illuminated implant regions; and

creating a library comprised of a plurality of calculated trace profiles of implant regions having varying implant profiles.

2. The method of claim 1, further comprising generating an additional trace profile for an additional plurality of implant regions formed in said substrate or additional substrates, said additional plurality of implant regions having an implant profile different from said first plurality of implant regions.

3. The method of claim 1, wherein forming a first plurality of implant regions in said substrate comprises forming a first plurality of implant regions to thereby define a grating structure in said substrate.

4. The method of claim 1, wherein said first plurality of implant regions are comprised of N-type dopant material or P-type dopant material.

5. The method of claim 1, wherein said first plurality of implant regions are illuminated using at least one of a multiple wavelength light source and a single wavelength light source.

6. The method of claim 1, wherein said implant profile is comprised of at least one of a width, a depth, a dopant concentration level, and a dopant concentration profile of said implant regions.

7. A method of measuring profiles of implant regions formed in a semiconducting substrate, comprising:

forming a plurality of implant regions in a semiconducting substrate;

illuminating said plurality of implant regions;

measuring light reflected off the substrate to generate a profile trace for said implant regions;

comparing the generated profile trace to a target profile trace; and

modifying, based upon a deviation between the generated profile trace and the target profile trace, at least one parameter of an ion implant process used to form implant regions on subsequently processed substrates.

8. The method of claim 7, further comprising correlating the generated profile trace to a profile trace from a library, the profile trace from the library having an associated implant region profile.

9. The method of claim 8, further comprising modifying, based upon a deviation between the generated profile trace and a profile trace from the library, at least one parameter of an ion implant process used to form implant regions on subsequently processed substrates.

10. The method of claim 7, wherein measuring the reflected light comprises measuring the intensity of the reflected light.

11. The method of claim 7, further comprising providing a library of calculated profile traces, each of which correspond to a unique profile of an implanted region.

12. The method of claim 7, wherein measuring light reflected off the substrate to generate a profile trace for said implant regions is performed prior to the implanted regions being subjected to an anneal process or a diffusion process.

13. The method of claim 7, wherein measuring light reflected off the substrate to generate a profile trace for said implant regions is performed after the implanted regions have been subjected to an anneal process or a diffusion process.

14. The method of claim 7, wherein modifying at least one parameter of an ion implant process comprises modifying at least one of an implant energy, an implant angle, a dopant material, and a dopant material concentration.

15. A method of measuring profiles of implant regions formed in a semiconducting substrate, comprising:

forming a plurality of implant regions in a semiconducting substrate;

illuminating said plurality of implant regions;

measuring light reflected off the substrate to generate a profile trace for said implant regions;

comparing the generated profile trace to a calculated profile trace in a library, the calculated profile trace having an associated implant region profile; and

modifying, based upon said comparison of the generated profile trace and the calculated profile trace, at least one parameter of an ion implant process used to form implant regions on subsequently processed substrates.

16. The method of claim 15, further comprising comparing the generated profile trace to a target profile trace from said library.

17. The method of claim 16, further comprising modifying, based upon a comparison of the generated profile trace and the target profile trace, at least one parameter of an ion implant process used to form implant regions on subsequently processed substrates.

18. The method of claim 15, wherein measuring the reflected light comprises measuring the intensity of the reflected light.

19. The method of claim 15, further comprising providing a library of calculated profile traces in a library, each of which correspond to a unique profile of an implanted region.

20. The method of claim 15, wherein measuring light reflected off the substrate to generate a profile trace for said implant regions is performed prior to the implanted regions being subjected to an anneal process or a diffusion process.

21. The method of claim 15, wherein measuring light reflected off the substrate to generate a profile trace for said implant regions is performed after the implanted regions have been subjected to an anneal process or a diffusion process.

22. The method of claim 15, wherein modifying at least one parameter of an ion implant process comprises modifying at least one of an implant energy, an implant angle, a dopant material, and a dopant material concentration.

23. A method of measuring profiles of implant regions formed in a semiconducting substrate, comprising:

forming a plurality of implant regions in a semiconducting substrate;

illuminating said plurality of implant regions;

measuring light reflected off the substrate to generate a profile trace for said implant regions;

providing a library comprised of a plurality of calculated profile traces, each of which correspond to a unique profile of an implanted region;

comparing the generated profile trace to at least one of said calculated profile traces from said library; and

modifying, based upon said comparison of the generated profile trace and the calculated profile trace, at least one parameter of an ion implant process used to form implant regions on subsequently processed substrates.

24. The method of claim 23, further comprising comparing the generated profile trace to a target profile trace.

25. The method of claim 24, further comprising modifying, based upon a deviation between the generated profile trace and the target profile trace, at least one parameter of an ion implant process used to form implant regions on subsequently processed substrates.

26. The method of claim 23, wherein measuring the reflected light comprises measuring the intensity of the reflected light.

27. The method of claim 23, wherein measuring light reflected off the substrate to generate a profile trace for said implant regions is performed prior to the implanted regions being subjected to an anneal process or a diffusion process.

28. The method of claim 23, wherein measuring light reflected off the substrate to generate a profile trace for said implant regions is performed after the implanted regions have been subjected to an anneal process or a diffusion process.

29. The method of claim 23, wherein modifying at least one parameter of an ion implant process comprises modifying at least one of an implant energy, an implant angle, a dopant material and a dopant material concentration.

30. A method of measuring profiles of implant regions formed in a semiconducting substrate, comprising;

forming a plurality of implant regions in a semiconducting substrate;

illuminating said plurality of implant regions;

measuring light reflected off the substrate to generate a profile trace for said implant regions;

comparing the generated profile trace to a target profile trace; and

modifying, based upon a deviation between the generated profile trace and the target profile trace, at least one parameter of an ion implant process used to form implant regions on subsequently processed substrates, said at least one parameter comprised of at least one of an implant energy, an implant angle, a dopant material, and a dopant material concentration.

31. The method of claim 30, further comprising comparing the generated profile trace to a calculated profile trace in a library, the calculated profile trace having an associated implant region profile.

32. The method of claim 31, further comprising modifying, based upon said comparison of the generated profile trace and the calculated profile trace, at least one parameter of an ion implant process used to form implant regions on subsequently processed substrates.

33. The method of claim 30, wherein measuring the reflected light comprises measuring the intensity of the reflected light.

34. The method of claim 30, further comprising providing a library of historical profile traces, each of which correspond to a unique profile of an implanted region.

35. The method of claim 30, wherein measuring light reflected off the substrate to generate a profile trace for said implant regions is performed prior to the implanted regions being subjected to an anneal process or a diffusion process.

36. The method of claim 30, wherein measuring light reflected off the substrate to generate a profile trace for said implant regions is performed after the implanted regions have been subjected to an anneal process or a diffusion process.