Integrated circuits including organic interlayer dielectric layers and methods for fabricating the same

Patent metadata

Field	Value
Publication number	US-9576894-B2
Application number	US-201514729188-A
Country	US
Kind code	B2
Filing date	Jun 3, 2015
Priority date	Jun 3, 2015
Publication date	Feb 21, 2017
Grant date	Feb 21, 2017

Abstract

Integrated circuits and methods for fabricating integrated circuits are provided. In one example, a method for fabricating an integrated circuit includes depositing an organic dielectric material overlying a semiconductor substrate for forming an organic interlayer dielectric (OILD) layer. An opening is formed in the OILD layer and a conductive metal fill is deposited in the opening for forming a metal line and/or a via.

First claim

What is claimed is:

1. A method for fabricating an integrated circuit, the method comprising:
depositing an organic dielectric material overlying a semiconductor substrate for forming an organic interlayer dielectric (OILD) layer;
forming a patterned hard mask overlying the OILD layer to form a first target metal line trench pattern and a second target metal line trench pattern;
forming a patterned mask overlying the patterned hard mask and the second target metal line trench pattern to form a target via-hole pattern in the first target metal line trench pattern;
forming a via-hole extending through the target via-hole pattern and in the OILD layer;
removing the patterned mask overlying the second target metal line trench pattern;
forming a metal line trench extending through the second target metal line trench pattern and in the OILD layer;
depositing a conductive metal fill in the via-hole for forming a via and in the metal line trench for forming a metal line; and
planarizing the conductive metal fill to expose an upper surface portion of the OILD layer.

2. The method of claim 1 , wherein depositing the organic dielectric material comprises forming the OILD layer having a dielectric constant of from about 1.9 to about 4.

3. The method of claim 1 , wherein depositing the organic dielectric material comprises depositing the organic dielectric material selected from the group consisting of polyimides, polyamides, polyesters, aromatic polymers, polyarylene-ether, fluorine doped polyarylene-ether, fluorine doped amorphous carbon, polytetrafluoroethylene (PTFE), and combinations thereof.

4. The method of claim 1 , wherein depositing the organic dielectric material comprises depositing the organic dielectric material using a spin coating process.

5. The method of claim 1 , wherein forming the opening comprises selectively etching the OILD layer using a plasma etching process that uses CO 2 /CO, N 2 /H 2 , CO 2 , or NH 3 .

6. The method of claim 1 , wherein depositing the organic dielectric material comprises forming the OILD layer having a thickness of from about 30 to about 750 nm.

7. The method of claim 1 , further comprising forming an interlayer dielectric (ILD) layer of dielectric material overlying the semiconductor substrate, wherein depositing the organic dielectric material comprises forming the OILD layer overlying the ILD layer.

8. The method of claim 7 , wherein forming the via-hole comprises forming the via-hole extending through the OILD and ILD layers, and wherein forming the metal line trench comprises forming the metal line trench extending through the OILD layer, and not the ILD layer.

9. The method of claim 8 , wherein forming the via-hole comprises selectively etching the ILD layer using a plasma etching process that uses a fluorine based chemistry.

10. The method of claim 1 , wherein depositing the conductive metal fill in the via-hole and metal line trench comprises depositing additional conductive metal fill overlying the OILD layer, and wherein planarizing the conductive metal fill to expose an upper surface portion of the OILD layer further comprises planarizing using a CMP process to remove the additional conductive metal fill and to expose the upper surface portion of the OILD layer.

11. A method for fabricating an integrated circuit, the method comprising:
forming an interlayer dielectric (ILD) layer of dielectric material overlying a metallization layer above a semiconductor substrate, wherein the metallization layer comprises a metal line;
depositing an organic dielectric material overlying the ILD layer for forming an organic interlayer dielectric (OILD) layer;
forming a patterned hard mask overlying the OILD layer to form a first target metal line trench pattern and a second target metal line trench pattern;
forming a patterned mask overlying the patterned hard mask and the second target metal line trench pattern to form a target via-hole pattern in the first target metal line trench pattern;
selectively etching, through the target via-hole pattern, the OILD layer and the ILD layer to form a via-hole extending towards the metal line of the metallization layer;
removing the patterned mask overlying the second target metal line trench pattern;
selectively etching, through the second target metal line trench pattern, the OILD layer to form a metal line trench;
depositing a conductive metal fill in the via-hole for forming a via electrically coupled to the metal line of the metallization layer and in the metal line trench for forming a metal line spaced from the metal line of the metallization layer;
planarizing the conductive metal fill to expose an upper surface portion of the OILD layer.

12. The method of claim 11 , further comprising depositing a nitrogen (N) doped silicon carbide layer overlying the metallization layer, wherein forming the ILD layer comprises forming the ILD layer overlying the N-doped silicon carbide layer.

13. The method of claim 12 , wherein selectively etching comprises selectively etching the OILD and ILD layers using the N-doped silicon carbide layer as an etch stop to expose a portion of the N-doped silicon carbide layer that is disposed directly above the metal line of the metallization layer.

14. The method of claim 13 , further comprising removing the portion of the N-doped silicon carbide layer using a plasma etching process.

15. The method of claim 13 , further comprising:
forming a metal cap overlying the metal line of the metallization layer, wherein depositing the N-doped silicon carbide layer comprises depositing the N-doped silicon carbide layer overlying the metal cap; and
removing the portion of the N-doped silicon carbide layer to expose the metal cap.

16. The method of claim 15 , further comprising removing the metal cap using a wet etching process to expose the metal line of the metallization layer.

17. The method of claim 11 , wherein forming the via comprises forming a liner in the via-hole.

18. The method of claim 17 , wherein forming the via further comprises depositing a conductive metal seed layer in the via-hole overlying the liner.

19. The method of claim 18 , wherein depositing the conductive metal fill in the via-hole further comprises depositing the conductive metal fill in the via-hole overlying the conductive metal seed layer.

20. An integrated circuit comprising:
a semiconductor substrate;
a metallization layer overlying the semiconductor substrate, the metallization layer comprising a metal line;
an organic interlayer dielectric (OILD) layer of organic dielectric material overlying the metallization layer and having a via-hole and a metal line trench formed in the OILD layer; and
a conductive metal fill disposed in the via-hole to form a via and in the metal line trench to form a metal line;
wherein the via is electrically coupled to the metal line of the metallization layer and the metal line is spaced from the metal line of the metallization layer; and
wherein an upper surface portion of the OILD layer is on the same plane as an upper surface portion of the conductive metal fill.

Assignees

• Globalfoundries Inc

Inventors

• Singh Sunil Kumar
• Srivastava Ravi Prakash
• Wu Xusheng
• Sehgal Akshey
• Tang Teck Jung

Classifications

• H10P50/73

  using masks for insulating materials · CPC title

• H10P14/6905

  being a silicon carbide or silicon carbonitride and not containing oxygen, e.g. SiC or SiC:H · CPC title

• H10P14/6342

  Liquid deposition, e.g. spin-coating, sol-gel techniques or spray coating · CPC title

• H10P14/683

  carbon-based polymeric organic materials, e.g. polyimides, poly cyclobutene or PVC · CPC title

• H10W20/083

  the openings being via holes penetrating underlying conductors · CPC title