Methods of forming patterns on substrates

• US 9,330,934 B2
• Filed: 05/18/2009
• Issued: 05/03/2016
• Est. Priority Date: 05/18/2009
• Status: Active Grant

• Current Assignee: Micron Technology, Inc.
• Original Assignee: Micron Technology, Inc.
• Inventors: Zhou, Baosuo, Schrinsky, Alex J.
• Primary Examiner(s): Ahmed, Shamim
• Assistant Examiner(s): GATES, BRADFORD M
• Application Number:
  US12/467,687
• Publication Number:
  US 20100291771A1
• Time in Patent Office: 2,542 Days
• Field of Search: 438/696
• US Class Current: 1/1
• CPC Class Codes: H01L 21/0337 characterised by the process involved to create the mask, e.g. lift-off masks, sidewalls, or to modify the mask, e.g. pre-treatment, post-treatment
• CPC Class Codes: H01L 21/0338 Process specially adapted to improve the resolution of the mask
• CPC Class Codes: H01L 21/31116 by dry-etching
• CPC Class Codes: H01L 21/31122 of layers not containing Si, e.g. PZT, Al2O3
• CPC Class Codes: H01L 21/31138 by dry-etching
• CPC Class Codes: H01L 21/31144 using masks
• CPC Class Codes: H01L 21/32139 using masks
• CPC Class Codes: H10B 41/40 characterised by the peripheral circuit region
• CPC Class Codes: H10B 41/43 comprising only one type of peripheral transistor

Abstract

Methods of forming a pattern on a substrate include forming carbon-comprising material over a base material, and spaced first features over the carbon-comprising material. Etching is conducted only partially into the carbon-comprising material and spaced second features are formed within the carbon-comprising material which comprise the partially etched carbon-comprising material. Spacers can be formed along sidewalls of the spaced second features. The carbon-comprising material can be etched through to the base material using the spacers as a mask. Spaced third features can be formed which comprise the anisotropically etched spacers and the carbon-comprising material.

Claims

1. A method of forming a pattern on a substrate, comprising:

forming a homogenous carbon-comprising material directly on a base material;

forming a first masking material over the homogenous carbon-comprising material, the first masking material being separated from the homogenous carbon-containing material by a hardmask material;

forming primary features in the first masking material and subsequently laterally trimming the primary features utilizing an isotropic plasma etch with an etch chemistry consisting of O₂, CF₄ and at least one member selected from the group consisting of HBr and Cl₂;

utilizing the trimmed primary features to form spaced first features comprising the hardmask material over the homogenous carbon-comprising material;

only partially etching into the homogenous carbon-comprising material and forming spaced second features within the homogenous carbon-comprising material which comprise the partially etched homogenous carbon-comprising material and overlying hardmask material;

forming spacers along sidewalls of the spaced second features; and

etching through the hardmask material of the second features and subsequently etching the homogenous carbon-comprising material to the base material using the spacers as a mask and forming spaced third features comprising the spacers and the homogenous carbon-comprising material.

2. The method of claim 1 wherein forming the spacers comprises depositing of a spacer-forming layer followed by anisotropic etching of the spacer-forming layer.

3. The method of claim 1 comprising processing the base material through a mask pattern comprising the spaced third features.

4. The method of claim 3 wherein the processing comprises etching into the base material.

5. The method of claim 1 wherein the spaced first features are not in direct physical touching contact with the homogenous carbon-comprising material.

6. The method of claim 1 wherein,

the base material comprises a stack comprising a tunnel dielectric material, floating gate material over the tunnel dielectric material, gate dielectric material over the floating gate material, and conductive control gate material over the gate dielectric material;

and

etching into the stack to form a pattern of charge storage transistor gate constructions using a mask pattern comprising the spaced third features.

7. The method of claim 1 wherein the homogenous carbon-comprising material comprises amorphous carbon.

8. The method of claim 7 wherein the homogenous carbon-comprising material consists essentially of amorphous carbon.

9. The method of claim 1 wherein the homogenous carbon-comprising material comprises transparent carbon.

10. The method of claim 9 wherein the homogenous carbon-comprising material consists essentially of transparent carbon.

11. The method of claim 1 wherein the homogenous carbon-comprising material comprises is polymeric.

12. The method of claim 11 wherein the homogenous carbon-comprising material consists essentially of polymeric material.

13. The method of claim 1 wherein the homogenous carbon-comprising material consists essentially of at least two of amorphous carbon, transparent carbon, and polymeric material.

14. The method of claim 13 wherein the homogenous carbon-comprising material consists essentially of amorphous carbon, transparent carbon, and polymeric material.

15. A method of forming a pattern on a substrate, comprising:

forming a carbon-comprising material on a base material, and a hardmask material over the carbon-comprising material;

forming a first masking material over the hardmask material;

forming spaced first features in the first masking material and subsequently laterally trimming the first features utilizing an isotropic plasma etch with an etch chemistry consisting of O₂, CF₄ and at least one member selected from the group consisting of HBr and Cl₂, to form trimmed spaced first features over the hardmask material;

etching through the hardmask material using the spaced first features as a mask followed by etching only partially into the carbon-comprising material and forming spaced second features within the carbon-comprising material which comprise the hardmask material and the underlying partially etched carbon-comprising material;

forming spacers along sidewalls of the spaced second features, the spacers being along sidewalls of the hardmask material and sidewalls of the carbon-comprising material;

after forming the spacers, etching to remove the hardmask material from between the spacers to leave the spacers projecting elevationally outward relative to an elevationally outermost part of the carbon-comprising material; and

after etching the hardmask material, etching through the carbon-comprising material to the base material using the spacers as a mask and forming spaced third features comprising the spacers and the carbon-comprising material.

16. The method of claim 15 wherein the spaced first features are formed by forming spaced primary features followed by laterally trimming width of the spaced primary features prior to the etching through the hardmask material.

17. The method of claim 15 wherein the spaced first features comprise photoresist.

18. The method of claim 17 wherein the spaced first features are formed by depositing and patterning photoresist to form spaced primary features followed by laterally trimming width of the photoresist of the spaced primary features prior to the etching through the hardmask material.

19. The method of claim 15 wherein the carbon-comprising material comprises at least one of amorphous carbon and transparent carbon.

20. The method of claim 15 wherein the carbon-comprising material comprises a polymer.

21. The method of claim 20 wherein the carbon-comprising material consists essentially of a polymer.

22. The method of claim 15 wherein the spaced first features and the carbon-comprising material are of different compositions.

23. The method of claim 15 wherein the carbon-comprising material has a thickness from about 700 Angstroms to about 2,000 Angstroms.

24. The method of claim 15 wherein the etching only partially into the carbon-comprising material is into less than one half of thickness of the carbon-comprising material.

25. The method of claim 15 wherein the etching only partially into the carbon-comprising material is into more than one half of thickness of the carbon-comprising material.

26. The method of claim 15 wherein the hardmask material comprises an antireflective coating.

27. The method of claim 15 wherein the hardmask material is inorganic.

28. The method of claim 15 comprising removing the spaced first features from over the base material prior to forming the spacers.

29. The method of claim 28 wherein the removing is completed during the etching only partially into the carbon-comprising material.

30. The method of claim 15 wherein the spacers comprise silicon.

31. The method of claim 15 wherein the forming of the spacers leaves alternating outwardly exposed regions of the carbon-comprising material and the hardmask material between immediately adjacent ones of the spacers.

32. The method of claim 15 comprising forming the spacers in physical touching contact with carbon of the carbon-comprising material.

33. The method of claim 15 comprising fabrication of integrated circuitry comprising an array circuitry area and a peripheral circuitry area, the spaced first features being at least in the array circuitry area, and further comprising lithographically patterning the peripheral circuitry area after the partial etching into the carbon-comprising material and before the etching through the carbon material.

34. The method of claim 33 wherein the lithographically patterning is conducted after forming the spacers.

35. The method of claim 15 wherein the carbon-comprising material is homogenous.

36. A method of forming a pattern on a substrate, comprising:

forming a carbon-comprising material directly on a semiconductive base material, a hardmask material over the carbon-comprising material, and spaced first features in a first masking material over the hardmask material;

laterally trimming the spaced first features utilizing an isotropic plasma etch with an etch chemistry consisting of O₂, CF₄ and at least one member selected from the group consisting of HBr and Cl₂, to formed narrowed spaced first features;

etching through the hardmask material using the narrowed spaced first features as a mask followed by etching only partially into the underlying carbon-comprising material and forming spaced second features within the carbon-comprising material which comprise the hardmask material and the partially etched carbon-comprising material;

forming spacers along sidewalls of the spaced second features, the spacers being along the hardmask material and the carbon-comprising material;

after forming the spacers, etching the hardmask material from between the spacers; and

etching through the carbon-comprising material to the base material using the spacers as a mask and forming spaced third features comprising the spacers and the carbon-comprising material, the carbon-comprising material consists essentially of at least one of amorphous carbon and transparent carbon.

37. A method of forming a pattern on a substrate, comprising:

forming a carbon-comprising material directly on a semi-conductive base material, an antireflective hardmask material over the carbon-comprising material, and spaced photoresist-comprising features over the hardmask material;

laterally trimming width of the photoresist-comprising features to form spaced photoresist-comprising first features over the antireflective hardmask material;

the lateral trimming utilizing an isotropic plasma etch with an etch chemistry consisting of O₂, CF₄ and at least one member selected from the group consisting of HBr and Cl₂;

etching through the antireflective hardmask material using the spaced photoresist-comprising first features as a mask and at least some of which remain after the etching through the antireflective hardmask material;

after the etching through the antireflective hardmask material, etching only partially into the carbon-comprising material and forming spaced second features within the carbon-comprising material which comprise the antireflective hardmask material and the underlying partially etched carbon-comprising material, the partial etching into the carbon-comprising material etching all remnant of the spaced photoresist-comprising first features from being received over the base material prior to completion of said partial etching into the carbon-comprising material;

forming anisotropically etched spacers along sidewalls of the spaced second features to leave alternating outwardly exposed regions of the carbon-comprising material and the antireflective hardmask material between immediately adjacent of the anisotropically etched spacers;

after forming the spacers, etching the antireflective hardmask material from between the anisotropically etched spacers to leave the spacers projecting elevationally outward relative to an elevationally outermost part of the underlying carbon-comprising material; and

etching through the carbon-comprising material to the base material using the anisotropically etched spacers as a mask and forming spaced third features comprising the anisotropically etched spacers and the carbon-comprising material.

38. The method of claim 37 wherein the carbon-comprising material is homogenous.

39. A method of forming a pattern on a substrate, comprising:

forming a material consisting essentially of carbon directly on a semiconductive base material, and spaced first features over the material consisting essentially of carbon;

laterally trimming the spaced first features utilizing an isotropic plasma etch with an etch chemistry consisting of O₂, CF₄ and at least one member selected from the group consisting of HBr and Cl₂;

only partially etching into the material consisting essentially of carbon and forming spaced second features within the material consisting essentially of carbon which comprise the partially etched material consisting essentially of carbon;

forming spacers along sidewalls of the spaced second features, the spacers being along hardmask material and material consisting essentially of carbon; and

after forming the spacers, etching through the material consisting essentially of carbon to the base material using the spacers as a mask and forming spaced third features comprising the spacers and the material consisting essentially of carbon.

40. The method of claim 39 wherein the material consisting essentially of carbon consists essentially of at least two of amorphous carbon, transparent carbon, and polymeric material.

41. The method of claim 40 wherein the material consisting essentially of carbon consists essentially of amorphous carbon, transparent carbon, and polymeric material.

42. A method of forming a pattern on a substrate, comprising:

forming a material consisting essentially of carbon directly on a semiconductive base material, a hardmask material over the material consisting essentially of carbon, and spaced first features over the hardmask material;

laterally trimming the spaced first features utilizing an isotropic plasma etch with an etch chemistry consisting of O₂, CF₄ and at least one member selected from the group consisting of HBr and Cl₂;

etching through the hardmask material using the spaced first features as a mask followed by etching only partially into the material consisting essentially of carbon and forming spaced second features within the material consisting essentially of carbon which comprise the hardmask material over the partially etched material consisting essentially of carbon;

forming spacers along sidewalls of the spaced second features, the spacers being along hardmask material and material consisting essentially of carbon;

etching the hardmask material from between the spacers; and

etching through the material consisting essentially of carbon to the base material using the spacers as a mask and forming spaced third features comprising the spacers and the material consisting essentially of carbon.

43. The method of claim 42 wherein the material consisting essentially of carbon consists essentially of at least two of amorphous carbon, transparent carbon, and polymeric material.

44. The method of claim 43 wherein the material consisting essentially of carbon consists essentially of amorphous carbon, transparent carbon, and polymeric material.

45. A method of forming a pattern on a substrate, comprising:

forming a material consisting essentially of carbon directly on a semiconductive base material, an antireflective hardmask material over the material consisting essentially of carbon, and spaced photoresist-comprising features over the hardmask material;

laterally trimming width of the photoresist-comprising features utilizing an isotropic plasma etch with an etch chemistry consisting of O₂, CF₄ and at least one member selected from the group consisting of HBr and Cl₂, to form narrowed spaced photoresist-comprising first features over the antireflective hardmask material;

etching through the antireflective hardmask material using the spaced photoresist-comprising first features as a mask and at least some of which remain after the etching through the antireflective hardmask material;

after the etching through the antireflective hardmask material, etching only partially into the underlying material consisting essentially of carbon and forming spaced second features within the material consisting essentially of carbon which comprise the antireflective hardmask material and the partially etched material consisting essentially of carbon, the partial etching into the material consisting essentially of carbon etching all remnant of the spaced photoresist-comprising first features from being received over the base material prior to completion of said partial etching into the material consisting essentially of carbon;

forming anisotropically etched spacers along sidewalls of the spaced second features to leave alternating outwardly exposed regions of the material consisting essentially of carbon and the antireflective hardmask material between immediately adjacent of the anisotropically etched spacers;

after forming the spacers, etching the antireflective hardmask material from between the anisotropically etched spacers; and

etching through the material consisting essentially of carbon to the base material using the anisotropically etched spacers as a mask and forming spaced third features comprising the anisotropically etched spacers and the material consisting essentially of carbon.

46. The method of claim 45 wherein the material consisting essentially of carbon consists essentially of at least two of amorphous carbon, transparent carbon, and polymeric material.

47. The method of claim 46 wherein the material consisting essentially of carbon consists essentially of amorphous carbon, transparent carbon, and polymeric material.