Large grain size conductive structure for narrow interconnect openings

• US 7,956,463 B2
• Filed: 09/16/2009
• Issued: 06/07/2011
• Est. Priority Date: 09/16/2009
• Status: Active Grant

• Current Assignee: Globalfoundries US Incorporated (GlobalFoundries, Inc.)
• Original Assignee: International Business Machines Corporation
• Inventors: Yang, Chih-Chao, Nogami, Takeshi, Rossnagel, Stephen M., Edelstein, Daniel C.
• Primary Examiner(s): POTTER, ROY KARL
• Application Number:
  US12/560,878
• Publication Number:
  US 20110062587A1
• Time in Patent Office: 629 Days
• Field of Search: 257/751, 257/E23.011, 257/750, 257/758, 257/767, 438/627, 438/629, 438/643, 438/648, 438/656
• US Class Current: 257/751
• CPC Class Codes: H01L 21/76805 the opening being a via or contact hole penetrating the underlying conductor
• CPC Class Codes: H01L 21/76844 Bottomless liners
• CPC Class Codes: H01L 21/76846 Layer combinations
• CPC Class Codes: H01L 21/76868 Forming or treating discontinuous thin films, e.g. repair, enhancement or reinforcement of discontinuous thin films
• 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 21/76883 Post-treatment or after-treatment of the conductive material

Abstract

An interconnect structure having reduced electrical resistance and a method of forming such an interconnect structure are provided. The interconnect structure includes a dielectric material including at least one opening therein. The at least one opening is filled with an optional barrier diffusion layer, a grain growth promotion layer, an agglomerated plating seed layer, an optional second plating seed layer a conductive structure. The conductive structure which includes a metal-containing conductive material, typically Cu, has a bamboo microstructure and an average grain size of larger than 0.05 microns. In some embodiments, the conductive structure includes conductive grains that have a (111) crystal orientation.

Claims

1. An interconnect structure comprising:

a dielectric material including at least one opening therein;

a grain growth promotion layer located within the at least one opening;

an agglomerated plating seed layer located above upper surfaces of said grain growth promotion layer; and

a conductive structure located within the at least one opening and atop upper surfaces of the agglomerated plating seed layer, said conductive structure comprising a metal-containing conductive material having a bamboo microstructure, an average grain size of larger than 0.05 microns, and conductive grains that have a (111) crystal orientation.

2. The interconnect structure of claim 1 wherein said dielectric material is one of SiO₂, a silsesquioxane, a C doped oxide that includes atoms of Si, C, O and H, or a thermosetting polyarylene ether.

3. The interconnect structure of claim 1 wherein said at least one opening is a line opening, a via opening, a combined line opening and via opening, or combinations thereof.

4. The interconnect structure of claim 1 wherein said grain growth promotion layer comprises Ru, Co, Ir, Rh, Mo, Re, Hf, Nb or alloys thereof.

5. The interconnect structure of claim 1 wherein said grain growth promotion layer has a thickness from 0.5 nm to 10 nm.

6. The interconnect structure of claim 1 further comprising a diffusion barrier located beneath said grain growth promotion layer, said diffusion bather comprising Ta, TaN, Ti, TiN, Ru, RuN, W, WN or any other material that can serve as a barrier to prevent conductive material from diffusing there through.

7. The interconnect structure of claim 1 wherein said agglomerated plating seed layer comprises Cu or a Cu-containing alloy.

9. The interconnect structure of claim 1 wherein said metal-containing conductive material of said conductive structure includes a conductive metal, an alloy comprising at least one conductive metal, or a conductive metal silicide.

10. The interconnect structure of claim 9 wherein said metal-containing conductive material is a conductive metal selected from the group consisting of Cu, Al, W and AlCu.

11. The interconnect structure of claim 1 wherein said conductive structure is present in an open-via bottom, an anchored-via bottom structure or a closed-bottom via.

12. The interconnect structure of claim 1 wherein said conductive structure is a copper-containing conductive structure.

8. An interconnect structure comprising:

a dielectric material including at least one opening therein;

a grain growth promotion layer located within the at least one opening;

an agglomerated plating seed layer located above upper surfaces of said grain growth promotion layer; and

a conductive structure located within the at least one opening and atop upper surfaces of the agglomerated plating seed layer, said conductive structure comprising a metal-containing conductive material having a bamboo microstructure and an average grain size of larger than 0.05 microns, wherein another plating seed layer is located between said agglomerated plating seed layer and said conductive structure.

13. A method of forming an interconnect structure comprising:

forming at least one opening in a dielectric material;

forming a grain growth promotion layer within said at least one opening;

forming an agglomerated plating seed layer within the at least one opening; and

forming a conductive structure within said at least one opening atop said agglomerated plating seed layer, said conductive structure including a metal-containing conductive material having a bamboo microstructure, an average grain size of larger than 0.05 microns, and conductive grains that have a (111) crystal orientation.

14. The method of claim 13 further comprising forming a diffusion barrier within the at least one opening prior to forming said grain growth promotion layer.

15. The method of claim 13 wherein said forming said grain growth promotion layer occurs at a deposition temperature of 400°

C. or less.

16. The method of claim 13 wherein said forming the agglomerated plating seed layer comprising depositing a plating seed layer;

and subjecting the plating seed layer to an anneal.

17. The method of claim 16 wherein said anneal is performed at a temperature from 200°

C. to 400°

C. in a reducing atmosphere or under vacuum.

19. The method of claim 13 wherein said forming the conductive structure comprises depositing the metal-containing conductive material within the at least one opening;

and annealing the metal-containing conductive material.

20. The method of claim 19 wherein said annealing is performed at a temperature from 80°

C. to 300°

C.

21. The method of claim 13 wherein said conductive structure is a copper-containing conductive structure.

18. A method of forming an interconnect structure comprising:

forming at least one opening in a dielectric material;

forming a grain growth promotion layer within said at least one opening;

forming an agglomerated plating seed layer within the at least one opening;

forming another plating seed layer atop the agglomerated plating seed layer; and

forming a conductive structure within said at least one opening atop said agglomerated plating seed layer, said conductive structure including a metal-containing conductive material having a bamboo microstructure and an average grain size of larger than 0.05 microns.