Methods of fabricating substrates

• US 8,247,302 B2
• Filed: 12/04/2008
• Issued: 08/21/2012
• Est. Priority Date: 12/04/2008
• Status: Active Grant

• Current Assignee: Micron Technology, Inc.
• Original Assignee: Micron Technology, Inc.
• Inventors: Sills, Scott, Sandhu, Gurtej S., deVilliers, Anton
• Primary Examiner(s): Deo, Duy
• Application Number:
  US12/328,464
• Publication Number:
  US 20100144153A1
• Time in Patent Office: 1,356 Days
• Field of Search: None
• US Class Current: 438/312
• CPC Class Codes: G03F 7/0035 Multiple processes, e.g. applying a further resist layer on an already in a previously step, processed pattern or textured surface
• CPC Class Codes: H01L 21/0273 characterised by the treatment of photoresist layers
• 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 21/31138 by dry-etching

Abstract

A method of fabricating a substrate includes forming spaced first features and spaced second features over a substrate. The first and second features alternate with one another and are spaced relative one another. Width of the spaced second features is laterally trimmed to a greater degree than any lateral trimming of width of the spaced first features while laterally trimming width of the spaced second features. After laterally trimming of the second features, spacers are formed on sidewalls of the spaced first features and on sidewalls of the spaced second features. The spacers are of some different composition from that of the spaced first features and from that of the spaced second features. After forming the spacers, the spaced first features and the spaced second features are removed from the substrate. The substrate is processed through a mask pattern comprising the spacers. Other embodiments are disclosed.

Claims

1. A method of fabricating a substrate, comprising:

forming spaced first features and spaced second features over a substrate, the first and second features alternating with one another and being spaced relative one another;

laterally trimming width of the spaced second features to a greater degree than any lateral trimming of width of the spaced first features while laterally trimming width of the spaced second features;

after the laterally trimming, forming spacers on sidewalls of the spaced first features and on sidewalls of the spaced second features, the spacers being of some different composition from that of the spaced first features and from that of the spaced second features;

after forming the spacers, removing the spaced first features and the spaced second features from the substrate; and

after the removing of the spaced first and second features from the substrate, processing the substrate through a mask pattern comprising the spacers.

2. The method of claim 1 wherein the forming of the spaced second features comprises etching material from which the spaced second feature are formed while no etch mask is received anywhere over the substrate.

3. The method of claim 1 wherein the spaced second features are formed to comprise second material received over first material, the first and second materials being of some different composition.

4. The method of claim 1 wherein forming the spacers comprises deposition of a spacer-forming layer followed by maskless anisotropic etching thereof.

5. The method of claim 1 wherein forming the spacers comprises depositing an alterable material over the spaced first features and the spaced second features and altering the alterable material with material from the spaced first features and with material from the spaced second features to form altered material which comprises the spacers.

6. The method of claim 1 wherein no lateral width trimming of the spaced first features occurs during the laterally trimming of width of the spaced second features.

7. The method of claim 1 wherein the laterally trimming of width of the spaced second features comprises etching;

and

further comprising treating outermost surfaces of the spaced first features to provide resistance of the spaced first features to said etching.

8. The method of claim 7 wherein no lateral width trimming of the spaced first features occurs during said etching to laterally trim width of the spaced second features.

9. A method of fabricating a substrate, comprising:

forming spaced first features over a substrate;

depositing a first material over the spaced first features which is of some different composition from that of the spaced first features;

depositing a second material over the first material, the second material being of some different composition from that of the first material;

removing only a portion of the second material to expose the first material and form spaced second material received over the first material;

after forming the spaced second material, etching the first material from between the spaced second material and forming spaced second features which comprise spaced second material received over first material, the second features being spaced from the first features;

after the etching of the first material, laterally trimming width of the spaced second features;

after the laterally trimming, forming spacers on sidewalls of the spaced first features and on sidewalls of the spaced second features, the spacers being of some different composition from that of the spaced first features and from that of the spaced second features;

after forming the spacers, removing the first features and the second features from the substrate; and

after the removing of the first features and the second features from the substrate, processing the substrate through a mask pattern comprising the spacers.

10. The method of claim 9 wherein the second material has a planar outermost surface prior to any removing of the second material.

11. The method of claim 9 wherein forming the spacers comprises deposition of a spacer-forming layer followed by maskless anisotropic etching thereof.

12. The method of claim 9 wherein forming the spacers comprises depositing an alterable material over the spaced first features and the spaced second features and altering the alterable material with material from the spaced first features and with material from the spaced second features to form altered material which comprises the spacers.

13. The method of claim 9 wherein the spacers of the mask pattern have at least two different thicknesses.

14. The method of claim 9 wherein the spacers of the mask pattern comprise alternating first and second pairs of immediately adjacent spacers, the spacers of the first pair having a first common thickness and the spacers of the second pair having a second common thickness, the first and second thicknesses being different.

15. A method of fabricating a substrate, comprising:

forming spaced first features over a substrate;

depositing a first material over the spaced first features which is of some different composition from that of the spaced first features;

depositing a second material over the first material, the second material being of some different composition from that of the first material;

removing only a portion of the second material to expose the first material and form spaced second material received over the first material;

after forming the spaced second material, etching the first material from between the spaced second material and forming spaced second features which comprise spaced second material received over first material, the second features being spaced from the first features;

after the etching of the first material, laterally trimming width of the spaced second features;

after the laterally trimming, depositing an alterable material over the spaced first features and the spaced second features and altering the alterable material with material from the spaced first features and with material from the spaced second features to form altered material on sidewalls of the spaced first features and on sidewalls of the spaced second features;

after the altering, removing the first features and the second features from the substrate; and

after removing the first features and the second features from the substrate, processing the substrate through a mask pattern comprising the altered material.

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

17. The method of claim 15 wherein forming the spaced first features comprises forming spaced mask features followed by laterally trimming the spaced mask features to reduce their respective widths.

18. The method of claim 17 wherein the mask pattern has pitch of about one fourth that of the spaced mask features.

19. The method of claim 15 wherein the second material has a planar outermost surface prior to any removing of the second material.

20. The method of claim 15 wherein the altering occurs during deposition of the alterable material.

21. The method of claim 15 wherein the altering occurs after completion of the deposition of the alterable material.

22. The method of claim 15 wherein no altering occurs until after completion of the deposition of the alterable material.

23. The method of claim 15 wherein the altering alters a portion of the alterable material adjacent each of the spaced first features and the spaced second features to form the altered material while leaving portions of the alterable material distal the spaced first features and the spaced second features unaltered.

24. The method of claim 23 comprising etching the distal portions away selectively relative to the altered material.

25. The method of claim 15 wherein the altering forms altered material over tops of the spaced first features and over tops of the spaced second features.

26. The method of claim 15 wherein the alterable material has a planar outermost surface.

27. A method of fabricating a substrate, comprising:

forming spaced first features over a substrate;

depositing an alterable material over the spaced first features and altering the alterable material with material from the spaced first features to form altered material on sidewalls of the spaced first features;

depositing a first material over the altered material which is of some different composition from that of the altered material;

removing only a portion of the first material to expose the altered material and form spaced first material;

after forming the spaced first material, etching the altered material from between the spaced first material and the spaced first features;

after the etching of the altered material, laterally trimming width of the spaced first material;

after the laterally trimming, forming anisotropically etched spacers on sidewalls of the spaced first features and on sidewalls of the spaced first material, the anisotropically etched spacers being of some different composition from that of the spaced first features and from that of the spaced first material;

after forming the anisotropically etched spacers, removing the spaced first features and the spaced first material from the substrate; and

after removing the spaced first features and the spaced first material from the substrate, processing the substrate through a mask pattern comprising the anisotropically etched spacers.

28. The method of claim 27 wherein the first material is of the same composition as that of the spaced first features.

29. The method of claim 27 wherein the first material is of some different composition from that of the spaced first features.

30. The method of claim 27 wherein the first material has a planar outermost surface prior to any removing of the first material.

31. The method of claim 27 wherein the spaced first features comprise photoresist and the alterable material comprises one or more inorganic components dispersed in an organic composition that is cross-linkable upon exposure to acid, wherein the material from the spaced first features includes acid, and the altering the alterable material comprises forming cross-links within the organic composition upon exposure to the acid in the material from the spaced first features.

32. The method of claim 31 wherein the one or more inorganic components includes silicon.

33. The method of claim 31 wherein the one or more inorganic components includes metal.

34. A method of fabricating a substrate, comprising:

forming spaced first features over a substrate;

depositing an alterable material over the spaced first features and altering only some of the alterable material with material from the spaced first features to form altered material on sidewalls of the spaced first features and leave alterable material elevationally over and between the altered material;

after the alternating, removing only a portion of the alterable material to expose the altered material and form spaced alterable material;

after forming the spaced alterable material, etching the altered material from between the spaced alterable material and the spaced first features;

after the etching of the altered material, laterally trimming width of the spaced alterable material;

after the laterally trimming, forming anisotropically etched spacers on sidewalls of the spaced first features and on sidewalls of the spaced alterable material, the anisotropically etched spacers being of some different composition from that of the spaced first features and from that of the spaced alterable material;

after forming the anisotropically etched spacers, removing the spaced first features and the spaced alterable material from the substrate; and

after removing the spaced first features and the spaced alterable material from the substrate, processing the substrate through a mask pattern comprising the anisotropically etched spacers.

35. A method of fabricating a substrate, comprising:

forming spaced first features over a substrate;

depositing a first alterable material over the spaced first features and altering the first alterable material with material from the spaced first features to form first altered material on sidewalls of the spaced first features;

depositing a first material over the first altered material which is of some different composition from that of the first altered material;

removing only a portion of the first material to expose the first altered material and form spaced first material;

after forming the spaced first material, etching the first altered material from between the spaced first material and the spaced first features;

after the etching of the first altered material, laterally trimming width of the spaced first material;

after the laterally trimming, depositing a second alterable material over the spaced first features and the spaced first material and altering the second alterable material with material from the spaced first features and with material from the spaced first material to form second altered material on sidewalls of the spaced first features and on sidewalls of the spaced first material;

after forming the second altered material, removing the spaced first features and the spaced first material from the substrate; and

after the removing of the spaced first features and spaced first material from the substrate, processing the substrate through a mask pattern comprising the second altered material.

36. The method of claim 35 wherein the first material has a planar outermost surface prior to any removing of the first material.

37. A method of fabricating a substrate, comprising:

forming spaced first features over a substrate;

depositing a first alterable material over the spaced first features and altering only some of the first alterable material with material from the spaced first features to form first altered material on sidewalls of the spaced first features and leave first alterable material elevationally over and between the first altered material;

after the altering of the first alterable material, removing only a portion of the first alterable material to expose the first altered material and form spaced first alterable material;

after forming the spaced first alterable material, etching the first altered material from between the spaced first alterable material and the spaced first features;

after the etching of the first altered material, laterally trimming width of the spaced first alterable material;

after the laterally trimming, depositing a second alterable material over the spaced first features and the spaced first alterable material and altering the second alterable material with material from the spaced first features and with material from the spaced alterable material to form second altered material on sidewalls of the spaced first features and on sidewalls of the spaced alterable material;

after forming the second altered material, removing the spaced first features and the spaced first alterable material from the substrate; and

after the removing of the spaced first features and spaced first alterable material from the substrate, processing the substrate through a mask pattern comprising the second altered material.