Self-trimming method on looped patterns

• US 6,632,741 B1
• Filed: 07/19/2000
• Issued: 10/14/2003
• Est. Priority Date: 07/19/2000
• Status: Expired due to Fees

• Current Assignee: Snap, Inc.
• Original Assignee: International Business Machines Corporation
• Inventors: Clevenger, Lawrence A., Hsu, Louis Lu-Chen, Radens, Carl J., Mandelman, Jack A.
• Primary Examiner(s): Utech, Benjamin L.
• Assistant Examiner(s): Tran, Binh X.
• Application Number:
  US09/619,664
• Time in Patent Office: 1,182 Days
• Field of Search: 438/706, 438/723, 438/724, 438/725, 438/756, 438/757, 438/689, 438/696
• US Class Current: 438/689
• CPC Class Codes: H01L 21/0334 characterised by their size, orientation, disposition, behaviour, shape, in horizontal or vertical plane

Abstract

A method of self-trimming pattern, includes forming a pattern containing a plurality of regular or irregular features within a first material deposited on a substrate, depositing a conformal layer of second material, and etching the second material to form spacers of the second material along the sidewalls of the features in the first material.

Claims

1. A method of self-trimming a pattern, comprising:

forming a pattern containing a plurality of densely packed features using a first material deposited on a substrate;

forming sidewall spacers using a second material along the sidewalls of said pattern in said first material;

depositing and etching back a third material, such that said third material covers a portion of said sidewall spacers; and

etching, without a mask, to remove said sidewall spacers exposed to an outer edge and not covered by said third material,

wherein said pattern is a looped pattern.

2. A method of self-trimming a pattern, comprising:

forming a pattern within a first material deposited on a substrate;

depositing a conformal layer of a second material;

etching said second material to form spacers of said second material along the sidewalls of predetermined patterns in said first material; and

depositing and etching back, without a mask, a conformal layer of a third material to fully expose the spacers at exterior boundaries.

3. The method of claim 2, wherein said etching comprises an anisotropic etching.

4. The method of claim 2, wherein a pitch of said first material and said spacer pattern is 2F representing two minimum non-phase shift, lithographically-patternable feature sizes.

5. The method of claim 2, wherein a pitch of adjacent spacers in a spacer pair is 1F representing one minimum non-phase shift, lithographically-patternable feature size.

6. The method of claim 2, wherein said method is devoid of a distinct lithographic masking level to trim loop regions of the spacers.

7. The method of claim 2, wherein said substrate comprises a dielectric.

8. The method of claim 2, wherein said method is for producing a half-pitch conductor with trim for a bitline wiring level for a dynamic random access memory (DRAM) array.

9. The method of claim 2, wherein said sidewalls of predetermined patterns comprises a looped pattern.

10. The method of claim 2, wherein said predetermined patterns comprise line patterns.

11. The method of claim 2, wherein said depositing and etching back partially exposes the spacers between adjacent lines of said first material.

12. The method of claim 2, wherein said pattern contains a plurality of lines and spaces.

13. The method of claim 12, further comprising:

depositing a third material to fill said spaces of said pattern in said first deposited material.

14. The method of claim 13, wherein said first material and said third material comprise a same material.

15. The method of claim 2, wherein said first material comprises one of silicon dioxide and silicon nitride for forming a mandrel.

16. The method of claim 15, wherein said second material comprises an electrically conductive material.

17. The method of claim 16, wherein said electrically conductive material comprises at least one of Al, W, TiN, Cu, TiW, Ta, and alloys thereof.

18. The method of claim 2, wherein said second material comprises an electrically conductive material.

19. The method of claim 18, wherein said electrically conductive material comprises polysilicon.

20. The method of claim 2, wherein said first material comprises a conductive material and said second material comprises an electrically insulating material.

21. The method of claim 20, wherein said electrically insulating material comprises one of silicon nitride and silicon dioxide.

22. The method of claim 2, further comprising depositing a conformal gapfill blocking film between a gap between adjacent spacers.

23. The method of claim 22, wherein said conformal gapfill blocking film comprises a chemical vapor deposition (CVD) film.

24. The method of claim 23, wherein said CVD film comprises boro-phosphorous silicate glass (BPSG).

25. The method of claim 22, wherein said gapfill blocking film comprises at least one of a dielectric, a photoresist, a polymer, a spin-on-glass (SOG), a chemical vapor deposited (CVD) diamond, and boro-phosphorous silicate glass (BPSG).

26. A method comprising:

forming a pattern within a first material deposited on a substrate;

depositing a conformal layer of a second material;

etching said second material to form spacers of said second material along the sidewalls of predetermined patterns in said first material;

depositing a third material to fill said spaces of said pattern in said first deposited material;

etching back said third deposited fill material to expose the spacers at exterior boundaries, said etching back partially removing said third deposited material from between adjacent lines of said first material;

removing said exposed spacers via an etching; and

stripping the remaining said third deposited fill material,

wherein said pattern contains a plurality of lines and spaces.

27. A method of self-trimming a pattern, comprising:

forming a pattern within a first material deposited on a substrate;

depositing a conformal layer of a second material;

etching said second material to form spacers of said second material along the sidewalls of predetermined patterns in said first material;

depositing a conformal gapfill blocking film between a gap between adjacent spacers; and

isotropically partially removing the gapfill blocking film by etching, wherein said etching is selective to the spacer material.

28. The method of claim 27, further comprising;

removing, via an isotropic etch, the spacer material which is not masked by the remaining gapfill blocking film, such that a predetermined exposed spacer material along the pattern is removed.

29. A method comprising:

forming a pattern within a first material deposited on a substrate;

depositing a conformal layer of a second material;

etching said second material to form spacers of said second material along the sidewalls of predetermined patterns in said.first material;

depositing a third material to fill said spaces of said pattern in said first deposited material; and

removing at least one of the third material and the first material by etching selective to the spacer material,

wherein said pattern contains a plurality of lines and spaces.