Method for forming metal wiring structure

• US 20070082132A1
• Filed: 03/03/2006
• Published: 04/12/2007
• Est. Priority Date: 10/07/2005
• Status: Active Grant

• Current Assignee: ASM Japan K.K. (ASM International NV)
• Original Assignee: ASM Japan K.K. (ASM International NV)
• Inventors: Shimizu, Akira, Shinriki, Hiroshi
• Granted Patent: US 7,785,658 B2
• Time in Patent Office: Days
• US Class Current: 427/255.394
• CPC Class Codes: C23C 16/0245 by etching with a plasma
• CPC Class Codes: C23C 16/18 from metallo-organic compounds
• CPC Class Codes: C23C 16/36 Carbonitrides
• CPC Class Codes: C23C 16/45529 specially adapted for making a layer stack of alternating different compositions or gradient compositions
• CPC Class Codes: C23C 16/45542 Plasma being used non-continuously during the ALD reactions
• CPC Class Codes: H01L 21/02063 the processing being the formation of vias or contact holes
• CPC Class Codes: H01L 21/28562 Selective deposition
• CPC Class Codes: H01L 21/3105 After-treatment
• CPC Class Codes: H01L 21/76814 post-treatment or after-treatment, e.g. cleaning or removal of oxides on underlying conductors
• CPC Class Codes: H01L 21/76826 by contacting the layer with gases, liquids or plasmas
• CPC Class Codes: H01L 21/76831 in via holes or trenches, e.g. non-conductive sidewall liners
• CPC Class Codes: H01L 21/76846 Layer combinations
• CPC Class Codes: H01L 23/53238 Additional layers associated with copper layers, e.g. adhesion, barrier, cladding layers
• CPC Class Codes: H01L 23/53295 Stacked insulating layers
• CPC Class Codes: H01L 28/90 having vertical extensions

Abstract

A method for forming a metal wiring structure includes: (i) providing a multi-layer structure including an exposed wiring layer and an exposed insulating layer in a reaction space; (ii) introducing an —NH2 or >NH terminal at least on an exposed surface of the insulating layer in a reducing atmosphere; (iii) introducing a reducing compound to the reaction space and then purging a reaction space; (iv) introducing a metal halide compound to the reaction space and then purging the reaction space; (v) introducing a gas containing N and H and then purging the reaction space; (vi) repeating steps (iii) to (v) in sequence to produce a metal-containing barrier layer; and (vii) forming a metal film on the metal-containing barrier layer.

Claims

1. A method for forming a metal wiring structure including a metal-containing barrier layer, comprising, for producing the metal-containing barrier layer:

(i) providing a multi-layer structure including an exposed wiring layer and an exposed insulating layer in a reaction space;

(ii) introducing a terminal containing N at least on an exposed surface of the insulating layer in a reducing atmosphere;

(iii) introducing a reducing compound to the reaction space to reduce the introduced terminal, and then purging a reaction space;

(iv) introducing a metal halide compound to the reaction space to replace the introduced reducing compound, and then purging the reaction space; and

(v) introducing a gas containing N to provide a terminal containing N on a surface formed by the introduced metal halide, and then purging the reaction space.

2. The method according to claim 1, wherein in step (ii), the terminal containing N is an —

NH2 or >

NH terminal.

3. The method according to claim 1, further comprising:

(vi) repeating steps (iii) to (v) in sequence to produce the metal-containing barrier layer; and

(vii) forming a metal film on the metal-containing barrier layer, said metal film comprising a metal other than a metal constituting the wiring layer.

4. The method according to claim 1, further comprising, prior to step (ii), a step of introducing a plasma or radicals of a reducing gas containing H2 to the reaction space to reduce an oxide film formed on an exposed surface of the wiring layer.

5. The method according to claim 4, wherein step (ii) comprises treating the exposed surface of the wiring layer and the exposed surface of the insulating layer with a plasma or radicals including excited NH3, excited NH2, or excited N2/H2, or N2H2.

6. The method according to claim 1, wherein step (ii) comprises treating an exposed surface of the wiring layer and the exposed surface of the insulating layer with a plasma or radicals including excited NH3, excited NH2, or excited N2/H2.

7. The method according to claim 6, wherein step (ii) uses a plasma or radicals including excited N2/H2 derived from a gas containing N2 and H2 wherein a partial pressure of N2 is 5%-50%.

8. The method according to claim 7, wherein the insulating layer is constituted by SiOC.

9. The method according to claim 1, wherein the insulating layer is constituted by a material selected from the group consisting of silicon carbide, N-doped silicon carbide, silicon nitride, silicon oxide, C-doped silicon oxide, and dielectric material formed of organo-silicon.

10. The method according to claim 1, wherein steps (iii) to (v) perform atomic layer deposition.

11. The method according to claim 1, wherein the reducing compound in step (iii) is selected from the group consisting of diborane, alkylborane, disilane, monosilane, and alkylsilane.

12. The method according to claim 1, wherein the metal halide in step (iv) includes a metal selected from the group consisting of W, Ta, and Ti.

13. The method according to claim 1, wherein the gas containing N and H in step (v) is NH3.

14. The method according to claim 1, wherein the metal-containing barrier layer is constituted by at least a metal, carbon, and nitrogen.

15. The method according to claim 3, wherein the metal film is a Ru film or Ta film.

16. The method according to claim 3, wherein step (vii) comprises:

(a) introducing a Ru source gas;

(b) purging the reaction space;

(c) introducing a gas containing H and N;

(d) purging the reaction space; and

(e) repeating steps (a) to (d).

17. The method according to claim 16, wherein the gas containing H and N is NH3 or a mixture of N2 and H2.

18. The method according to claim 16, wherein the gas is excited by a plasma.

19. The method according to claim 3, further comprising a step of (viii) forming a copper layer on the metal film.

20. The method according to claim 3, wherein step (ii), steps (iii) to (vi), and step (vii) are conducted in respective reaction spaces and are conducted in sequence without breaking a vacuum.

21. The method according to claim 19, wherein step (ii), steps (iii) to (vi), step (vii), and step (viii) are conducted in respective reaction spaces and are conducted in sequence without breaking a vacuum.

22. The method according to claim 1, wherein step (iii) is conducted to reduce the —

NH2 or >

NH with the reducing compound, thereby providing —

NH-A or >

N-A, wherein A is derived from the reducing compound.

23. The method according to claim 22, wherein step (iv) is conducted to substitute the metal halide compound for the A, thereby providing —

NH-M or >

N-M, wherein M is derived from the metal halide compound.

24. The method according to claim 23, wherein step (v) is conducted to substitute —

NH2 or >

NH for a halogen in the M, thereby providing —

NH-M′

-Tr or >

N-M′

-Tr, wherein M′

is derived from the M, and Tr is the —

NH2 or >

NH.

25. The method according to claim 1, wherein the wiring layer is made of copper.

26. The method according to claim 1, wherein the insulating layer is porous and has pores, said method further comprising, prior to step (ii),

forming a pore-sealing layer to block pores at least on an exposed surface of the insulating layer;

and

removing a portion of the pore-sealing layer, if any, formed on an exposed surface of the wiring layer, wherein the exposed surface of the insulating layer in step (ii) on which the terminal containing N is introduced is comprised of a surface of the pore-sealing layer and the exposed surface of the wiring layer.

27. The method according to claim 26, wherein the pore-sealing layer is constituted by a material selected from the group consisting of SiC, SiOC, silicon nitride, amorphous carbon, and SiO2.

28. The method according to claim 26, wherein the exposed surface of the insulating layer forms at least one trench, and the exposed surface of the wiring layer is formed at a bottom of the trench.

29. The method according to claim 19, wherein the insulating layer is porous and has pores, said method further comprising, prior to step (ii),

forming a pore-sealing layer to block pores at least on an exposed surface of the insulating layer;

and

removing a portion of the pore-sealing layer, if any, formed on an exposed surface of the wiring layer, wherein the exposed surface of the insulating layer in step (ii) on which the terminal containing N is introduced is comprised of a surface of the pore-sealing layer and the exposed surface of the wiring layer,

wherein the exposed surface of the insulating layer forms at least one trench, and the exposed surface of the wiring layer is formed at a bottom of the trench, said method further comprising, subsequent to step (viii),

planarizing the copper layer by chemical mechanical polishing (CMP) to form an interconnect copper line filled in the trench covered with the metal film.

30. A method for producing a capacitor, comprising:

forming the metal wiring structure according to claim 1, wherein the metal film serves as a lower electrode;

forming a thin dielectric film on the metal wiring structure; and

forming an upper electrode on the thin dielectric film.

31. The method according to claim 30, wherein the metal film is a Ru film.

32. A method for forming a metal wiring structure including a metal-containing barrier layer, comprising, for producing the metal-containing barrier layer:

(i) providing a multi-layer structure including an exposed wiring layer and an exposed insulating layer;

(ii) introducing —

NH2 or >

NH at least on an exposed surface of the insulating layer in a reducing atmosphere;

(iii) reducing the —

NH2 or >

NH with a reducing compound to provide —

NH-A or >

N-A, wherein A is derived from the reducing compound;

(iv) substitute a metal halide compound for the A to provide —

NH-M or >

N-M, wherein M is derived from the metal halide compound; and

(v) substitute —

NH2 or >

NH for a halogen in the M to provide —

NH-M′

-Tr or >

N-M′

-Tr, wherein M′

is derived from the M, and Tr is the —

NH2 or >

NH.

33. The method according to claim 32, further comprising:

(vi) repeating steps (iii) to (v) to produce the metal-containing barrier layer; and

(vii) forming a metal film on the metal-containing barrier layer, said metal film comprising a metal other than a metal constituting the wiring layer.

34. The method according to claim 32, wherein the insulating layer is porous and has pores, said method further comprising, prior to step (ii),

forming a pore-sealing layer to block pores at least on an exposed surface of the insulating layer;

and

removing a portion of the pore-sealing layer, if any, formed on an exposed surface of the wiring layer, wherein the exposed surface of the insulating layer in step (ii) on which the —

NH2 or >

NH is provided is comprised of a surface of the pore-sealing layer and the exposed surface of the wiring layer.

35. A method for forming a multiple-layer structure including a metal-containing barrier layer, comprising, for producing the metal-containing barrier layer:

(i) providing an insulating layer in a reaction space;

(ii) introducing an —

NH2 or >

NH terminal at least on an exposed surface of the insulating layer in a reducing atmosphere;

(iii) introducing a reducing compound to the reaction space and then purging a reaction space;

(iv) introducing a metal halide compound to the reaction space and then purging the reaction space; and

(v) introducing a gas containing N and H and then purging the reaction space;

.

36. The method according to claim 35, further comprising:

(vi) repeating steps (iii) to (v) in sequence to produce the metal-containing barrier layer; and

(vii) forming a metal film on the metal-containing barrier layer.

37. The method according to claim 35, wherein the insulating layer is porous and has pores, said method further comprising, prior to step (ii),

forming a pore-sealing layer to block pores at least on an exposed surface of the insulating layer;

and

removing a portion of the pore-sealing layer, if any, formed on an exposed surface of the wiring layer, wherein the exposed surface of the insulating layer in step (ii) on which the —

NH2 or >

NH terminal is introduced is comprised of a surface of the pore-sealing layer and the exposed surface of the wiring layer.