Methods of forming a pattern on a substrate

• US 8,629,048 B1
• Filed: 07/06/2012
• Issued: 01/14/2014
• Est. Priority Date: 07/06/2012
• Status: Active Grant

• Current Assignee: Micron Technology, Inc.
• Original Assignee: Micron Technology, Inc.
• Inventors: Sipani, Vishal, deVilliers, Anton J.
• Primary Examiner(s): Picardat, Kevin M
• Application Number:
  US13/542,913
• Publication Number:
  US 20140011364A1
• Time in Patent Office: 557 Days
• Field of Search: 438/595, 438/587, 438/588, 438/618, 438/622, 438/761, 438/778
• US Class Current: 438/595
• 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 longitudinally elongated first lines and first sidewall spacers longitudinally along opposite sides of the first lines elevationally over an underlying substrate. Longitudinally elongated second lines and second sidewall spacers are formed longitudinally along opposite sides of the second lines. The second lines and the second sidewall spacers cross elevationally over the first lines and the first sidewall spacers. The second sidewall spacers are removed from crossing over the first lines. The first and second lines are removed in forming a pattern comprising portions of the first and second sidewall spacers over the underlying substrate. Other methods are disclosed.

Claims

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

forming longitudinally elongated first lines and first sidewall spacers longitudinally along opposite sides of the first lines elevationally over an underlying substrate;

forming longitudinally elongated second lines and second sidewall spacers longitudinally along opposite sides of the second lines, the second lines and the second sidewall spacers crossing elevationally over the first lines and the first sidewall spacers;

removing the second sidewall spacers from crossing over the first lines; and

removing the first and second lines in forming a pattern comprising portions of the first and second sidewall spacers over the underlying substrate.

2. The method of claim 1 comprising forming the first sidewall spacers as a ring around the respective first lines.

3. The method of claim 1 comprising forming the second sidewall spacers as a ring around the respective second lines.

4. The method of claim 1 wherein the first and second sidewall spacers are formed at the same time.

5. The method of claim 1 wherein forming the second sidewall spacers comprises depositing and subsequently anisotropically etching a masking material.

6. The method of claim 5 wherein the removing of the second sidewall spacers from crossing over the first lines comprises continuing the anisotropically etching of the masking material without stopping the etching between the forming of the second sidewall spacers and the removing of the second sidewall spacers from crossing over the first lines.

7. The method of claim 1 wherein the second sidewall spacers extend completely between immediately adjacent first lines after the removing of the second sidewall spacers from crossing over the first lines.

8. The method of claim 1 wherein the second lines are elevationally thicker between the first lines than atop the first lines.

9. The method of claim 1 wherein the underlying substrate has a planar elevationally outermost surface over which the first and second lines are received, each of the first and second lines extending to the elevationally outermost surface.

10. The method of claim 9 wherein the second lines are elevationally thicker between the first lines than atop the first lines.

11. The method of claim 10 comprising forming the first and second lines to have respective planar elevationally outermost surfaces, the elevationally outermost surfaces of the first lines being coplanar relative one another and the elevationally outermost surfaces of the second lines being coplanar relative one another.

12. The method of claim 1 comprising:

after removing the first and second lines, forming fill material laterally of the portions of the first and second sidewall spacers;

removing remaining of the portions of the first and second sidewall spacers in forming a contact opening mask comprising the fill material; and

using the contact opening mask while etching contact openings into the underlying substrate.

13. The method of claim 1 comprising after removing the first and second lines, etching into the underlying substrate using remaining of the first and second sidewall spacers as an etch mask.

14. The method of claim 1 comprising forming predecessor second lines which are laterally trimmed in forming the second lines, the predecessor second lines having a pitch and a half thereof, the pattern having a minimum feature width that is half of the half-pitch.

15. The method of claim 1 wherein the portions of the first and second spacers in the pattern are generally rectangular in horizontal cross-section having adjacent sides of unequal length.

16. The method of claim 15 wherein the rectangular portions have longer sides that are about three times length of the shorter sides.

17. The method of claim 15 wherein the rectangular portions have longer sides that are more than three times length of the shorter sides.

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

forming longitudinally elongated first lines elevationally over an underlying substrate;

forming longitudinally elongated second lines and masking material longitudinally along opposite sides of the second lines, the second lines and the masking material crossing elevationally over the first lines, the second lines and the masking material being elevationally thicker between the first lines than elevationally over the first lines;

removing the masking material from crossing over the first lines while leaving at least some of the masking material along sidewalls of the second lines between immediately adjacent first lines; and

removing the first and second lines in forming a pattern comprising spaced regions of the masking material over the underlying substrate.

19. The method of claim 18 comprising forming the masking material longitudinally along opposite sides of the first lines.

20. The method of claim 18 comprising forming the first and second lines to have respective planar elevationally outermost surfaces.

21. The method of claim 20 wherein the elevationally outermost surfaces of the first lines are coplanar relative one another and the elevationally outermost surfaces of the second lines are coplanar relative one another.

22. The method of claim 18 comprising forming the first and second lines to be of different compositions.

23. The method of claim 18 wherein forming the second lines comprises depositing and patterning a spin-on material.

24. A method of forming a pattern on a substrate sequentially comprising:

forming longitudinally elongated first lines elevationally over an underlying substrate;

forming longitudinally elongated second lines elevationally over and crossing the first lines;

forming a masking material over tops and sides of the crossing first and second lines to less than fill void space between immediately adjacent second lines;

removing the masking material to expose the tops of the first and second lines; and

removing the first and second lines in forming a pattern comprising spaced regions of the masking material over the underlying substrate.

25. The method of claim 24 wherein the removing of the masking material is from over all of the tops of the first and second lines.

26. A method of forming a pattern on a substrate sequentially comprising:

forming longitudinally elongated first lines elevationally over an underlying substrate;

forming longitudinally elongated second lines elevationally over and crossing the first lines, the second lines being elevationally thicker between the first lines than over tops of the first lines;

forming a masking material over tops, sides and ends of the crossing first and second lines to less than fill void space between immediately adjacent second lines;

removing the masking material from over all of the tops and all of the ends of the first and second lines while leaving at least some of the masking material along sidewalls of the second lines between immediately adjacent first lines; and

removing the first and second lines in forming a pattern comprising spaced regions of the masking material over the underlying substrate.

27. The method of claim 26 wherein the removing of the masking material is by anisotropic etching.

28. The method of claim 26 wherein the removing of the masking material is by mask-less anisotropic etching.