SELF-ALIGNED MULTI-PATTERNING PROCESS FLOW WITH ALD GAPFILL SPACER MASK

• US 20180138040A1
• Filed: 11/11/2016
• Published: 05/17/2018
• Est. Priority Date: 11/11/2016
• Status: Active Grant

• Current Assignee: Lam Research Corporation
• Original Assignee: Lam Research Corporation
• Inventors: LaVoie, Adrien
• Granted Patent: US 10,832,908 B2
• Time in Patent Office: Days
• CPC Class Codes: C23C 16/042 using masks
• CPC Class Codes: C23C 16/045 Coating cavities or hollow spaces, e.g. interior of tubes; Infiltration of porous substrates
• CPC Class Codes: C23C 16/45536 Use of plasma, radiation or electromagnetic fields
• CPC Class Codes: C23C 16/56 After-treatment
• CPC Class Codes: H01L 21/02164 the material being a silicon oxide, e.g. SiO2
• CPC Class Codes: H01L 21/02167 the material being a silicon carbide not containing oxygen, e.g. SiC, SiC:H or silicon carbonitrides H01L21/02126 and H01L21/0214 take precedence
• CPC Class Codes: H01L 21/0217 the material being a silicon nitride not containing oxygen, e.g. SixNy or SixByNz H01L21/02126 and H01L21/0214 take precedence
• CPC Class Codes: H01L 21/02186 the material containing titanium, e.g. TiO2
• CPC Class Codes: H01L 21/02274 in the presence of a plasma [PECVD]
• CPC Class Codes: H01L 21/0228 deposition by cyclic CVD, e.g. ALD, ALE, pulsed CVD
• CPC Class Codes: H01L 21/0332 characterised by their composition, e.g. multilayer masks, materials
• 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 21/31051 Planarisation of the insulating layers H01L21/31058 takes precedence
• CPC Class Codes: H01L 21/31111 by chemical means

Abstract

Methods and apparatuses for forming symmetrical spacers for self-aligned multiple patterning processes are described herein. Methods include depositing gapfill material by atomic layer deposition over a patterned substrate including core material and a target layer, planarizing substrate, and etching the core material to form symmetrical spacers. Gapfill material may be deposited for a duration insufficient to completely fill features such that features are underfilled.

Claims

1. A method comprising:

providing a substrate having a core material patterned to form gaps and a target layer;

depositing gapfill material conformally over the core material such that gapfill material is deposited in the gaps on the substrate;

planarizing the substrate to form a planar surface comprising the gapfill material and the core material; and

selectively etching the core material to form symmetrically shaped spacers used as a mask to etch the target layer,

wherein the symmetrically shaped spacers having sidewalls substantially perpendicular to a top surface of the symmetrically shaped spacer.

2. The method of claim 1, wherein the gapfill material is deposited by atomic layer deposition.

3. The method of claim 1, wherein the gapfill material is deposited by atomic layer deposition for a duration insufficient to completely fill the gaps.

4. The method of claim 1, wherein the gapfill material is selected from the group consisting of silicon oxide, silicon nitride, silicon carbide, and titanium oxide.

5. The method of claim 1, wherein the gaps have openings less than about x nm and the gapfill material is deposited for a duration sufficient to deposit the gapfill material to a thickness between about 0.4×

x nm and about 0.5×

x nm.

6. The method of claim 5, wherein x is 50.

7. The method of claim 5, wherein x is less than 50.

8. The method of claim 1, wherein critical dimension between symmetrically shaped spacers in the mask is less than about 50 nm.

9. The method of claim 1, wherein the symmetrically shaped spacers are used for multiple patterning techniques.

11. The method of claim 1, wherein the symmetrically shaped spacers comprise the gapfill material.

12. The method of claim 1, further comprising prior to depositing the gapfill material, depositing another conformal film over the substrate and directionally etching the another conformal film to form sidewall spacers on the sidewalls of the core material.

13. The method of claim 12, wherein selectively etching the substrate to form the symmetrically shaped spacers comprises removing the core material and the gapfill material selective to the sidewall spacers.

14. The method of claim 1, wherein selectively etching the substrate to form the symmetrically shaped spacers comprises removing the core material selective to the gapfill material.

15. The method of claim 1, wherein the core material comprises carbon.

16. The method of claim 2, wherein the core material is selected from the group consisting of spin on carbon, diamond-like carbon, and gapfill ashable hard mask.

17. The method of claim 1, wherein depositing the gapfill material comprises exposing the substrate to alternating pulses of a silicon-containing precursor and an oxidizing plasma.

10. (canceled)

18. A method comprising:

providing a substrate having a core material patterned to form gaps and a target layer;

depositing gapfill material conformally over the core material such that gapfill material is deposited in the gaps on the substrate;

planarizing the substrate to form a planar surface comprising the gapfill material and the core material;

selectively etching the core material to form symmetrically shaped spacers; and

etching the target layer using the symmetrically shaped spacers as a mask,

wherein the symmetrically shaped spacers have a planar top profile with vertical surfaces of the symmetrically shaped spacers oriented at or about 90°

from a top horizontal surface of the symmetrically shaped spacers.

19. A method comprising:

providing a substrate having a core material patterned to form gaps and a target layer;

depositing gapfill material conformally over the core material such that gapfill material is deposited in the gaps on the substrate;

planarizing the substrate to form a planar surface comprising the gapfill material and the core material, the gapfill material having a horizontal planar top profile; and

selectively etching the core material to form symmetrically shaped spacers used as a mask to etch the target layer.