SELF-ALIGNED BARRIER AND CAPPING LAYERS FOR INTERCONNECTS

• US 20110163062A1
• Filed: 10/20/2010
• Published: 07/07/2011
• Est. Priority Date: 10/23/2009
• Status: Active Grant

• Current Assignee: President and Fellows of Harvard College (Harvard Corporation)
• Original Assignee: President and Fellows of Harvard College (Harvard Corporation)
• Inventors: LIN, Youbo, BHANDARI, Harish B., GORDON, Roy G., AU, Yeung
• Granted Patent: US 8,569,165 B2
• Time in Patent Office: Days
• US Class Current: 216/13
• CPC Class Codes: C23C 16/18 from metallo-organic compounds
• CPC Class Codes: C23C 16/34 Nitrides C23C16/303 takes precedence
• CPC Class Codes: C23C 16/401 containing silicon
• CPC Class Codes: H01L 21/28506 of conductive layers
• CPC Class Codes: H01L 21/28556 by chemical means, e.g. CVD, LPCVD, PECVD, laser CVD H01L21/28518 - H01L21/28537 and H01L21/28568 take precedence
• CPC Class Codes: H01L 21/28562 Selective deposition
• CPC Class Codes: H01L 21/288 from a liquid, e.g. electrolytic deposition
• CPC Class Codes: H01L 21/2885 using an external electrical current, i.e. electro-deposition
• 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 21/76829 characterised by the formation of thin functional dielectric layers, e.g. dielectric etch-stop, barrier, capping or liner layers
• CPC Class Codes: H01L 21/76831 in via holes or trenches, e.g. non-conductive sidewall liners
• CPC Class Codes: H01L 21/76832 Multiple layers
• CPC Class Codes: H01L 21/76834 formation of thin insulating films on the sidewalls or on top of conductors H01L21/76831 takes precedence
• CPC Class Codes: H01L 21/76835 Combinations of two or more different dielectric layers having a low dielectric constant H01L21/76832 takes precedence
• CPC Class Codes: H01L 21/76843 formed in openings in a dielectric
• CPC Class Codes: H01L 21/76849 the layer being positioned on top of the main fill metal
• CPC Class Codes: H01L 21/76853 characterized by particular after-treatment steps
• CPC Class Codes: H01L 21/76862 Bombardment with particles, e.g. treatment in noble gas plasmas; UV irradiation
• CPC Class Codes: H01L 21/76867 characterized by methods of formation other than PVD, CVD or deposition from a liquids PVD H01L21/2855; CVD H01L21/28556; deposition from liquids H01L21/288
• CPC Class Codes: H01L 21/76871 : Layers specifically deposited to enhance or enable the nucleation of further layers, i.e. seed layers
• CPC Class Codes: H01L 21/76873 : for electroplating
• CPC Class Codes: H01L 21/76874 : for electroless plating
• CPC Class Codes: H01L 21/76876 : for deposition from the gas phase, e.g. CVD
• CPC Class Codes: H01L 21/76877 : Filling of holes, grooves or trenches, e.g. vias, with conductive material
• CPC Class Codes: H01L 23/5226 : Via connections in a multilevel interconnection structure
• CPC Class Codes: H01L 23/528 : Geometry or layout of the interconnection structure H01L27/0207 takes precedence; algorithms G06F30/00
• CPC Class Codes: H01L 23/53238 : Additional layers associated with copper layers, e.g. adhesion, barrier, cladding layers
• CPC Class Codes: H01L 2924/00 : Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
• CPC Class Codes: H01L 2924/0002 : Not covered by any one of groups H01L24/00, H01L24/00 and H01L2224/00

Abstract

An interconnect structure for integrated circuits for copper wires in integrated circuits and methods for making the same are provided. Mn, Cr, or V containing layer forms a barrier against copper diffusing out of the wires, thereby protecting the insulator from premature breakdown, and protecting transistors from degradation by copper. The Mn, Cr, or V containing layer also promotes strong adhesion between copper and insulators, thus preserving the mechanical integrity of the devices during manufacture and use, as well as protecting against failure by electromigration of the copper during use of the devices and protecting the copper from corrosion by oxygen or water from its surroundings. In forming such integrated circuits, certain embodiments of the invention provide methods to selectively deposit Mn, Cr, V, or Co on the copper surfaces while reducing or even preventing deposition of Mn, Cr, V, or Co on insulator surfaces. Catalytic deposition of copper using a Mn, Cr, or V containing precursor and an iodine or bromine containing precursor is also provided.

Claims

1. A process for forming an integrated circuit interconnect structure, said process comprising:

a) providing a partially-completed and planarized interconnect structure comprising an electrically insulating surface and an electrically conductive, copper-containing surface;

b) depositing a protecting agent that comprises two or more compounds over said electrically insulating surface to synergistically reduce affinity of said electrically insulating surface to a precursor comprising manganese, cobalt, chromium or vanadium;

c) selectively depositing a metal selected from the group consisting of manganese, cobalt, chromium and vanadium on at least a part of the electrically conductive copper-containing surface.

2. The process as in claim 1, wherein said selectively depositing a metal is carried out by CVD or ALD.

3. The process as in claim 1, wherein said protecting agent reduces reactivity of said insulating surface with said precursor comprising manganese.

4. The process as in claim 1, wherein said protecting agent reduces reactivity of said insulating surface with said precursor comprising cobalt.

5. The process as in claim 1, wherein said protecting agent reduces reactivity of said insulating surface with said precursor comprising chromium.

6. The process as in claim 1, wherein said protecting agent reduces reactivity of said insulating surface with said precursor comprising vanadium.

7. The process as in claim 1, wherein said protecting agent is selectively deposited on said electrically insulating surface.

8. The process as in claim 7, wherein said protecting agent comprises two or more alkylsilanes.

9. The process as in claim 8, wherein the alkylsilanes comprise compounds with one or more dialkylamide groups bonded to silicon.

10. The process as in claim 9, wherein the compounds with one or more dialkylamide groups bonded to silicon comprise bis(N,N-dialkylamino)dialkylsilanes and (N,N-dialkylamino)trialkylsilanes.

11. A process for forming an integrated circuit interconnect structure, said process comprising:

a) providing a partially-completed interconnect structure having one or more vias and trenches, said vias and trenches comprising sidewalls defined by one or more electrically insulating materials and electrically conductive copper-containing bottom regions;

b) depositing a layer comprising a nitride of a metal selected from the group consisting of manganese, chromium and vanadium on the partially-completed interconnect structure;

c) depositing copper within said one or more vias and trenches.

12. The process of claim 11, further comprising removing nitrogen from said layer comprising metal nitride prior to said depositing copper within said one or more vias and trenches.

13. The process as in claim 12 wherein said removing nitrogen is accomplished by contact of the structure with a hydrogen-containing plasma.

14. The process as in claim 11 wherein said depositing copper comprises electroplating or electroless plating from a liquid solution.

15. The process as in claim 11 wherein said depositing copper comprises deposition from the vapor phase by CVD or ALD.

16. The process as in claim 11, wherein said layer comprising a nitride of a metal comprises manganese nitride.

17. A process comprising:

depositing a metal containing layer from a vapor of a metal containing precursor, wherein the metal is selected from the group consisting of manganese, chromium and vanadium;

depositing an iodine or bromine containing material from a vapor of an iodine or bromine containing precursor, wherein the iodine or bromine containing material is chemisorbed on or in the metal containing layer; and

depositing a copper containing material from a vapor of a copper containing precursor, wherein the iodine or bromine containing material allows a catalytic deposition of copper containing material.

18. The process of claim 17, wherein said depositing an iodine or bromine containing material is carried out after said depositing a metal containing layer.

19. The process of claim 17, wherein the iodine or bromine containing material is chemisorbed on the surface of the metal containing layer.

20. The process of claim 17, wherein the metal containing layer is a manganese containing layer and the metal containing precursor is a manganese containing precursor.

21. The process of claim 20, wherein the manganese containing layer further contains nitrogen.

22. The process of claim 17, wherein the metal containing layer is a chromium containing layer and the metal containing precursor is a chromium containing precursor.

23. The process of claim 17, wherein the metal containing layer is vanadium containing layer and the metal containing precursor is a vanadium containing precursor.

24. The process of claim 17, further comprising:

depositing additional iodine or bromine containing material from a vapor of an iodine or bromine containing precursor onto said copper containing material; and

depositing additional copper containing material from a vapor of a copper containing precursor, wherein the additional iodine or bromine containing material allows a catalytic deposition of additional copper containing material.

25. The process of claim 24, wherein the additional copper containing material comprises copper and manganese.

26. The process of claim 24, wherein the additional copper containing material is co-deposited from a vapor of a manganese containing precursor.

27. The process of claim 20, wherein the manganese containing precursor comprises manganese amidinate.

28. The process of claim 27, wherein the manganese amidinate has the general structure

29. The process of claim 28 wherein R¹, R², R³, R^1′

, R^2′

and R^3′

are independently selected from the group consisting of hydrogen, alkyl, aryl, alkenyl, alkynyl, trialkylsilyl, alkylamide and fluoroalkyl groups.

30. The process of claim 29, wherein the manganese amidinate has the structure

31. The process of claim 17, wherein the copper containing precursor comprises copper amidinate.

32. The process of claim 31, wherein the copper amidinate has the general structure

33. The process of claim 32, wherein R¹, R², R³, R^1′

, R^2′

and R^3′

are independently selected from the group consisting of hydrogen, alkyl, aryl, alkenyl, alkynyl, trialkylsilyl, alkylamide and fluoroalkyl groups.

34. The process of claim 33, wherein the copper amidinate has the structure

35. The process of claim 17, wherein the copper is deposited on a partially-completed interconnect structure having one or more vias and trenches, said vias and trenches comprising sidewalls defined by one or more electrically insulating materials and electrically conductive copper-containing bottom regions.

36. The process of claim 35, wherein the deposited copper substantially fills said vias and trenches.

37. The process of claim 17, wherein the deposited copper has a manganese concentration in the range of about 0.1% to about 4%.

38. The process of claim 17, wherein the deposited copper has a manganese concentration in the range of about 0.2% to about 2%.

39. The process of claim 17, further comprising removing the iodine or bromine from at least a part of the surface of the copper-containing material.

40. The process of claim 39, wherein said removing the iodine or bromine includes an oxidation process.

41. The process of claim 40, wherein said oxidation process includes exposing the at least a part of the surface of the copper-containing material with an oxidant selected from the group consisting of hydrogen peroxide, sodium hypochlorite, sodium hypobromite, ozone, an oxygen plasma, and mixtures thereof.

42. The process of claim 40, wherein said removing the iodine or bromine further includes a reduction process.

43. The process of claim 42, wherein the reduction step includes a hydrogen plasma.

44. The process as in claim 39, further comprising modifying said at least a part of the surface of the copper-containing material after said removing the iodine or bromine to decrease deposition of copper.

45. The process of claim 44, wherein said modifying includes reaction of the copper surface with an alkanethiol.