Methods of forming a pattern on a substrate

• US 8,575,032 B2
• Filed: 05/05/2011
• Issued: 11/05/2013
• Est. Priority Date: 05/05/2011
• Status: Active Grant

• Current Assignee: Micron Technology, Inc.
• Original Assignee: Micron Technology, Inc.
• Inventors: Light, Scott L., deVilliers, Anton J.
• Primary Examiner(s): CAMPBELL, SHAUN M
• Application Number:
  US13/101,485
• Publication Number:
  US 20120282778A1
• Time in Patent Office: 915 Days
• Field of Search: 438/703
• US Class Current: 438/703
• 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 21/31144 using masks

Abstract

A method of forming a pattern on a substrate includes forming a repeating pattern of four first lines elevationally over an underlying substrate. A repeating pattern of four second lines is formed elevationally over and crossing the repeating pattern of four first lines. First alternating of the four second lines are removed from being received over the first lines. After the first alternating of the four second lines have been removed, elevationally exposed portions of alternating of the four first lines are removed to the underlying substrate using a remaining second alternating of the four second lines as a mask. Additional embodiments are disclosed and contemplated.

Claims

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

forming first features elevationally over an underlying substrate, the first features comprising longitudinally elongated first lines having first sidewall spacers received longitudinally along opposite sides thereof, first fill material being received laterally between the first sidewall spacers of laterally adjacent first features;

forming second features elevationally over and crossing the first features, the second features comprising longitudinally elongated second lines having second sidewall spacers received longitudinally along opposite sides thereof, second fill material being received laterally between the second sidewall spacers of laterally adjacent second features;

removing the second sidewall spacers from between the second lines and the second fill material; and

removing, to the underlying substrate, portions of the first sidewall spacers from between the first lines and the first fill material that are not covered by the second lines and the second fill material.

2. The method of claim 1 comprising after removing the portions of the first sidewall spacers to the underlying substrate, etching into the underlying substrate using remnant of the first and second features and the first and second fill materials as a mask and forming a plurality of contact openings extending to node locations in the underlying substrate.

3. The method of claim 2 wherein the underlying substrate comprises an outer hardmask material, the etching comprising:

etching a contact opening pattern into the hardmask material using the remnant of the first and second features and the first and second fill materials as a first mask; and

etching the plurality of the of contact openings into substrate material underlying the hardmask material using the contact opening pattern in the hardmask material as a second mask.

4. The method of claim 3 comprising etching the first mask away from over the hardmask material.

5. The method of claim 1 wherein the first fill material and the first lines are formed to be of different compositions.

6. The method of claim 1 wherein the first fill material and the first lines are formed to be of the same composition.

7. The method of claim 1 wherein the first fill material is formed to have an elevationally outermost surface that is elevationally coincident with or elevationally outward of elevationally outermost surfaces of the first sidewall spacers.

8. The method of claim 7 wherein the elevationally outermost surface of the first fill material is planar.

9. The method of claim 8 wherein the elevationally outermost surfaces of the first sidewall spacers are at a common elevation, the elevationally outermost surface of the first fill material being elevationally coincident with the elevationally outermost surfaces of the first sidewall spacers.

10. The method of claim 8 wherein the elevationally outermost surface of the first fill material is elevationally outward of the elevationally outermost surfaces of the first spacers.

11. The method of claim 1 wherein forming the first features over which the second features are formed comprises planarizing the first lines, the first sidewall spacers, and the first fill material elevationally inward to a coplanar elevationally outermost surface of the first lines, the first sidewall spacers, and the first fill material.

12. The method of claim 1 wherein removing the second sidewall spacers exposes underlying portions of the first sidewall spacers.

13. The method of claim 12 wherein removing the second sidewall spacers exposes all of the lateral width of the respective first sidewall spacers.

14. The method of claim 12 wherein removing the second sidewall spacers exposes only some of the lateral width of the respective first sidewall spacers.

15. The method of claim 1 wherein removing the second sidewall spacers does not expose the underlying first sidewall spacers.

16. The method of claim 1 wherein forming the first features comprises:

forming spaced longitudinally elongated lines;

forming the first sidewall spacers longitudinally along sidewalls of the spaced lines;

removing the spaced lines from between the first sidewall spacers; and

depositing the first fill material over the first sidewall spacers, laterally between the first sidewall spacers where the removed spaced lines were, and laterally between the first sidewall spacers of laterally adjacent first features.

17. The method of claim 16 comprising planarizing at least the first fill material back to at least the elevationally outermost surfaces of the first spacers.

18. The method of claim 17 comprising planarizing the first fill material and the first spacers elevationally inward to a coplanar elevationally outermost surface of the first lines, the first sidewall spacers, and the first fill material.

19. The method of claim 1 wherein the first and second features cross orthogonally relative one another.

20. The method of claim 1 wherein the first and second features cross non-orthogonally relative one another.

21. The method of claim 1 wherein the first and second features extend longitudinally straight linear.

22. The method of claim 1 wherein at least one of the collective first features and the collective second features respectively extend longitudinally curvilinear.

23. The method of claim 1 wherein the first fill material and the second fill material are of the same composition.

24. The method of claim 1 wherein the first fill material and the second fill material are of different compositions.

25. The method of claim 1 wherein the first fill material is received elevationally over the first lines and the first sidewall spacers, and over which the second features are formed;

and

after removing the second sidewall spacers, etching the first fill material to expose the first sidewall spacers and first lines there-beneath.

26. The method of claim 1 wherein the removing of the portions of the first sidewall spacers comprises anisotropic etching of material of the first sidewall spacers selectively relative to the first lines, the first fill material, the second lines, and the second fill material.

27. The method of claim 1 wherein forming the second features comprises:

forming spaced longitudinally elongated lines;

forming the second sidewall spacers longitudinally along sidewalls of the spaced lines;

removing the spaced lines from between the second sidewall spacers; and

depositing the second fill material over the second sidewall spacers, laterally between the second sidewall spacers where the removed spaced lines were, and laterally between the second sidewall spacers of laterally adjacent second features.

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

forming anisotropically etched first sidewall spacers elevationally over an underlying substrate;

forming anisotropically etched second sidewall spacers elevationally over and crossing the first sidewall spacers, intersections of the first and second sidewall spacers defining respective elevationally overlapped areas of the first sidewall spacers where the second sidewall spacers cross over the first sidewall spacers;

removing the second sidewall spacers where such cross over the first sidewall spacers and exposing the overlapped areas of the first sidewall spacers; and

removing material of the first sidewall spacers through the exposed overlapped areas to the underlying substrate while at least a majority of the area of the first sidewall spacers outside of the overlapped areas is masked.

29. The method of claim 28 wherein the second sidewall spacers are formed directly against the first sidewall spacers, and the removing of the second sidewall spacers exposes the overlapped areas of the first sidewall spacers.

30. The method of claim 28 wherein the second sidewall spacers are not formed directly against the first sidewall spacers, and the removing of the second sidewall spacers does not expose the overlapped areas of the first sidewall spacers.

31. The method of claim 28 wherein elevationally outermost surfaces of the first sidewall spacers are non-planar, and comprising planarizing the elevationally outermost surfaces of the first sidewall spacers prior to forming the second sidewall spacers.

32. The method of claim 28 wherein the removing of the second sidewall spacers removes all of such from the substrate.

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

forming a repeating pattern of four first lines elevationally over an underlying substrate;

forming a repeating pattern of four second lines elevationally over and crossing the repeating pattern of four first lines, each of the second lines comprising solid material;

after forming the first lines and the second lines, removing first alternating second lines of the four second lines from being received over the first lines; and

after removing the first alternating second lines of the four second lines, removing elevationally exposed portions of alternating first lines of the four first lines to the underlying substrate using a remaining second alternating of the four second lines as a mask.

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

forming first and second lines elevationally over an underlying substrate;

forming third and fourth lines elevationally over and crossing the first and second lines;

the third and fourth lines each comprising solid material;

the first, second, third, and fourth lines forming a quadrilateral there-between;

providing a pair of crossing lines within the quadrilateral, the crossing lines each comprising solid material; and

using the first line, the second line, the third line, the fourth line, and the pair of crossing lines as a mask while etching through material to form a pattern of four openings which are individually received within a respective different one of four corners of the quadrilateral.

35. The method of claim 34 comprising providing the pair of crossing lines to be centered within the quadrilateral.