Selective formation of metallic films on metallic surfaces

• US 8,956,971 B2
• Filed: 06/10/2011
• Issued: 02/17/2015
• Est. Priority Date: 06/10/2010
• Status: Active Grant

• Current Assignee: ASM International NV
• Original Assignee: ASM International NV
• Inventors: Haukka, Suvi P., Niskanen, Antti, Tuominen, Marko
• Primary Examiner(s): Kebede, Brook
• Application Number:
  US13/702,992
• Publication Number:
  US 20130189837A1
• Time in Patent Office: 1,348 Days
• Field of Search: 438/644, 438/651, 438/655, 438/672, 438/680, 438/687
• US Class Current: 438/655
• CPC Class Codes: C23C 16/0227 by cleaning or etching
• CPC Class Codes: C23C 16/14 Deposition of only one other metal element
• CPC Class Codes: C23C 16/45525 Atomic layer deposition [ALD]
• CPC Class Codes: H01L 21/02068 during, before or after processing of conductive layers, e.g. polysilicon or amorphous silicon layers
• CPC Class Codes: H01L 21/02697 Forming conducting materials on a substrate
• CPC Class Codes: H01L 21/28562 Selective deposition
• CPC Class Codes: H01L 21/32051 Deposition of metallic or metal-silicide layers
• CPC Class Codes: H01L 21/32053 of metal-silicide layers
• CPC Class Codes: H01L 21/76826 by contacting the layer with gases, liquids or plasmas
• CPC Class Codes: H01L 21/76829 characterised by the formation of thin functional dielectric layers, e.g. dielectric etch-stop, barrier, capping or liner layers
• CPC Class Codes: H01L 21/76838 characterised by the formation and the after-treatment of the conductors etching for patterning the conductors H01L21/3213
• CPC Class Codes: H01L 21/76849 the layer being positioned on top of the main fill metal
• CPC Class Codes: H01L 21/7685 the layer covering a conductive structure H01L21/76849 takes precedence
• CPC Class Codes: H01L 21/76883 Post-treatment or after-treatment of the conductive material

Abstract

Metallic layers can be selectively deposited on surfaces of a substrate relative to a second surface of the substrate. In preferred embodiments, the metallic layers are selectively deposited on copper instead of insulating or dielectric materials. In preferred embodiments, a first precursor forms a layer or adsorbed species on the first surface and is subsequently reacted or converted to form a metallic layer. Preferably the deposition temperature is selected such that a selectivity of above about 90% is achieved.

Claims

1. A method for selectively depositing a film on a substrate comprising a first metal surface and a second dielectric surface, the method comprising one or more deposition cycles, each cycle comprising:

contacting the substrate with a first precursor comprising silicon or boron to selectively form a layer of first material comprising Si or B on the first metal surface relative to the second dielectric surface; and

converting the first material on the first metal surface to a second metallic material by exposing the first material to a second precursor comprising metal, wherein the method has a selectivity for depositing material on the first metal surface relative to the second dielectric surface of above about 50%.

2. The method of claim 1, wherein the first metal surface comprises copper.

3. The method of claim 1, wherein the second metallic material comprises a metal nitride.

4. The method of claim 1, wherein the second metallic material comprises a transition metal.

5. The method of claim 4, wherein the second metallic material comprises tungsten.

6. The method of claim 1, wherein the metal surface comprises a noble metal.

7. The method of claim 1, wherein the metallic material comprises a metal silicide.

8. The method of claim 1, wherein the metallic material consists essentially of elemental metal.

9. The method of claim 1, wherein the second dielectric surface comprises SiO₂.

10. The method of claim 1, wherein the second dielectric surface comprises a low k material with a dielectric value of less than about 4.0.

11. The method of claim 1, wherein the first precursor comprises silane, disilane, or trisilane.

12. The method of claim 11, wherein the second precursor comprises WF₆, TaF₅, NbF₅, TiF₄, MoF_x, or VF_x.

13. The method of claim 1, wherein the first precursor is diborane.

14. The method of claim 1, wherein the material of the first surface is not converted or reacted to form another compound during the selective deposition.

15. The method of claim 1, wherein the second precursor comprises a metal halide.

16. The method of claim 1, wherein the process has a selectivity for depositing material on the first surface versus the second surface of about above 90%.

17. The method of claim 1, further comprising repeating the contacting and converting steps.

18. The method of claim 1, further comprising cleaning the substrate prior to the contacting introducing step.

19. The method of claim 1, wherein the first material has a thickness less than about 20 Å

.

20. The method of claim 1, wherein the temperature of the substrate is less than about 175°

C.

21. The method of claim 1, wherein the temperature of the substrate is selected such that the first material forms on the first metal surface with a selectivity of greater than about 90% versus the second dielectric surface.

22. The method of claim 1, wherein converting the first material to second material is a replacement reaction.

23. The method of claim 1, further comprising after the one or more deposition cycles:

contacting the substrate with a precursor comprising silicon or boron to form a layer comprising Si or B on the second metallic material.

24. The method of claim 23, further comprising oxidizing the layer comprising Si or B to form SiO₂ or B₂O₃.

25. The method of claim 24, further comprising removing the SiO₂ or B₂O₃ by exposing the SiO₂ or B₂O₃ to a metal halide source chemical.

26. The method of claim 1, wherein the one or more deposition cycles are carried out at a temperature less than about 150°

C.

27. A method for selectively depositing a film on a substrate comprising a first copper surface and a second dielectric surface, the method comprising one or more deposition cycles:

contacting the substrate with a first precursor comprising silicon to selectively form a layer of first material comprising Si or B over the first copper surface relative to the second dielectric surface; and

converting the first material to a second metallic material by subsequently exposing the first material to a second precursor comprising a metal fluoride;

wherein a temperature of the substrate is selected such that the first material forms on the first copper surface with a selectivity of greater than about 90% versus the second dielectric surface.

28. The method of claim 27, wherein the temperature of the substrate is less than about 150°

C.