Electroless deposition processes and compositions for forming interconnects

• US 20060252252A1
• Filed: 03/20/2006
• Published: 11/09/2006
• Est. Priority Date: 03/18/2005
• Status: Abandoned Application

• Current Assignee: Applied Materials Incorporated
• Original Assignee: Applied Materials Incorporated
• Inventors: Konecni, Anthony, Weidman, Timothy W., Shanmugasundram, Arulkumar, Stewart, Michael P., Krishna, Nety M., Zhu, Zhize
• Application Number:
  US11/385,290
• Publication Number:
  US 20060252252A1
• Time in Patent Office: Days
• US Class Current: 438/618
• CPC Class Codes: B82Y 30/00 Nanotechnology for materials or surface science, e.g. nanocomposites
• CPC Class Codes: C23C 16/0227 by cleaning or etching
• CPC Class Codes: C23C 16/0281 of metallic sub-layers C23C16/029 takes precedence
• CPC Class Codes: C23C 16/045 Coating cavities or hollow spaces, e.g. interior of tubes; Infiltration of porous substrates
• CPC Class Codes: C23C 16/14 Deposition of only one other metal element
• CPC Class Codes: C23C 18/1608 from pretreatment step, i.e. selective pre-treatment
• CPC Class Codes: C23C 18/1651 Two or more layers only obtained by electroless plating
• CPC Class Codes: C23C 18/1653 Two or more layers with at least one layer obtained by electroless plating and one layer obtained by electroplating
• CPC Class Codes: C23C 18/1678 Heating of the substrate
• CPC Class Codes: C23C 18/31 Coating with metals
• CPC Class Codes: C23C 18/32 Coating with nickel, cobalt or mixtures thereof with phosphorus or boron C23C18/50 takes precedence
• CPC Class Codes: C23C 18/34 using reducing agents
• CPC Class Codes: C23C 18/38 Coating with copper
• CPC Class Codes: C23C 18/40 using reducing agents
• CPC Class Codes: C23C 18/48 Coating with alloys
• CPC Class Codes: C25D 5/34 Pretreatment of metallic surfaces to be electroplated
• CPC Class Codes: H01L 21/02063 the processing being the formation of vias or contact holes
• CPC Class Codes: H01L 21/02074 the processing being a planarization of conductive layers
• CPC Class Codes: H01L 21/28518 the conductive layers comprising silicides H01L21/28537 takes precedence
• 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 21/288 : 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 21/76843 : formed in openings in a dielectric
• CPC Class Codes: H01L 21/76844 : Bottomless liners
• CPC Class Codes: H01L 21/76846 : Layer combinations
• CPC Class Codes: H01L 21/76847 : the layer being positioned within the main fill metal
• CPC Class Codes: H01L 21/76849 : the layer being positioned on top of the main fill metal
• CPC Class Codes: H01L 21/76855 : After-treatment introducing at least one additional element into the layer
• CPC Class Codes: H01L 21/76856 : by treatment in plasmas or gaseous environments, e.g. nitriding a refractory metal liner
• CPC Class Codes: H01L 21/76861 : Post-treatment or after-treatment not introducing additional chemical elements into the layer
• CPC Class Codes: H01L 21/76862 : Bombardment with particles, e.g. treatment in noble gas plasmas; UV irradiation
• CPC Class Codes: H01L 21/76874 : for electroless plating
• CPC Class Codes: H01L 21/76877 : Filling of holes, grooves or trenches, e.g. vias, with conductive material
• CPC Class Codes: H01L 21/76879 : by selective deposition of conductive material in the vias, e.g. selective C.V.D. on semiconductor material, plating plating on semiconductors in general H01L21/288
• 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

In one embodiment, a method for depositing a material on a substrate is provided which includes positioning a substrate containing a contact within a process chamber, exposing the substrate to at least one pretreatment step and depositing a fill the contact vias by an electroless deposition process. The pretreatment step contains multiple processes for exposing the substrate to a wet-clean solution, a hydrogen fluoride solution, a tungstate solution, a palladium activation solution, an acidic rinse solution, a complexing agent solution or combinations thereof. Generally, the HARC via contains a tungsten oxide surface and the shallow contact via may contain a tungsten silicide surface. In some example, the substrate is pretreated such that both vias are filled at substantially the same time by a nickel-containing material through an electroless deposition process.

Claims

1. A method of forming an interconnect on a silicon substrate, comprising:

providing a substrate containing an exposed tungsten-containing contact plug exposed that has an exposed gap formed therein;

exposing the substrate to a pretreatment process, wherein the pretreatment process is adapted to remove an oxide layer from a surface of the exposed tungsten-containing contact plug; and

filling the exposed gap with a fill material.

2. The method of claim 1, wherein the pretreatment process comprises exposing the substrate to a wet-clean solution having a pH value of less than about 5.

3. The method of claim 2, wherein the wet-clean solution has a hydrogen fluoride concentration within a range from about 0.1 wt % to about 2 wt %.

4. The method of claim 2, wherein the wet-clean solution further comprises a complexing agent that is selected from the group consisting of citric acid, EDTA, EDA, carboxylic acids, amines, salts thereof, derivatives thereof and combinations thereof.

5. The method of claim 1, wherein the step of filling the exposed gap is completed using an electroless deposition process, wherein the fill material is selected from the group consisting of cobalt boride (CoB), cobalt phosphide (CoP), cobalt tungsten phosphide (CoWP), cobalt tungsten boride (CoWB), cobalt molybdenum phosphide (CoMoP), cobalt molybdenum boride (CoMoB), cobalt rhenium boride (CoReB), cobalt rhenium phosphide (CoReP), nickel boride (NiB), nickel phosphide (NiP), nickel tungsten phosphide (NiWP), nickel tungsten boride (NiWB), nickel molybdenum phosphide (NiMoB), nickel molybdenum phosphide (NiMoP), nickel rhenium phosphide (NiReP), and nickel rhenium boride (NiReB).

6. The method of claim 1, wherein the fill material is selected from the group consisting of copper, cobalt, nickel and tungsten.

7. The method of claim 1, wherein the fill material is a dielectric material.

8. The method of claim 1, further comprising removing a portion of the exposed tungsten-containing contact plug to increase the size of the exposed gap.

9. The method of claim 8, wherein the step of removing a portion of the exposed tungsten-containing contact plug is performed using a wet-clean solution having a pH value of less than about 5.

10. A method of forming an interconnect on a silicon substrate, comprising:

providing a silicon substrate having a first dielectric layer which is disposed on a surface of the silicon substrate and a first aperture formed in the first dielectric layer, wherein a doped silicon containing region of the silicon substrate is exposed at the bottom of the first aperture;

filling the first aperture formed in the first dielectric layer with a tungsten containing layer, wherein the tungsten containing layer is in electrical communication with the doped silicon containing region;

removing an amount of the tungsten containing layer disposed on the first dielectric layer, wherein a gap formed in the tungsten containing layer during the step of filling the first aperture is exposed; and

depositing a material on the surface of the silicon substrate to substantially cover the gap formed in the tungsten containing layer.

11. The method of claim 10, further comprising exposing the substrate to a pretreatment process, wherein the pretreatment process is adapted to remove an oxide layer from a surface of the exposed tungsten containing layer.

12. The method of claim 11, wherein the pretreatment process further comprises exposing the substrate to a wet-clean solution having a pH value of less than about 5.

13. The method of claim 12, wherein wet-clean solution further comprises a complexing agent that is selected from the group consisting of citric acid, EDTA, EDA, carboxylic acids, amines, salts thereof, derivatives thereof and combinations thereof.

14. The method of claim 10, wherein the material is selected from the group consisting of metallic nickel (Ni), metallic cobalt (Co), cobalt boride (CoB), cobalt phosphide (CoP), cobalt tungsten phosphide (CoWP), cobalt tungsten boride (CoWB), cobalt molybdenum phosphide (CoMoP), cobalt molybdenum boride (CoMoB), cobalt rhenium boride (CoReB), cobalt rhenium phosphide (CoReP), nickel boride (NiB), nickel phosphide (NiP), nickel tungsten phosphide (NiWP), nickel tungsten boride (NiWB), nickel molybdenum phosphide (NiMoB), nickel molybdenum phosphide (NiMoP), nickel rhenium phosphide (NiReP), and nickel rhenium boride (NiReB).

15. The method of claim 10, further comprising;

forming a second dielectric layer over the first dielectric layer and the tungsten containing layer disposed in the first aperture; and

forming a second aperture in the second dielectric layer that is in communication with the tungsten containing layer disposed in the first aperture, wherein the step of forming the second aperture is formed before the step of depositing a material on the surface of the silicon containing substrate is performed.

16. A method of forming an interconnect on a silicon substrate, comprising:

providing a substrate containing first dielectric layer that contains at least one tungsten-containing contact plug that has an exposed surface;

forming a second dielectric layer over the first dielectric layer and the tungsten-containing contact plug;

forming a second aperture in the second dielectric layer that is in communication with the exposed surface of the tungsten-containing contact plug; and

selectively filling the second aperture with a fill material.

17. The method of claim 16, further comprising depositing a first metal layer over the exposed surface of the tungsten-containing contact plug and the second aperture before selectively filling the second aperture.

18. The method of claim 16, wherein the tungsten-containing contact plug has an exposed gap that comprises a portion of the exposed surface of the tungsten-containing contact plug, wherein the second aperture is in communication with the exposed surface and the exposed gap.

19. The method of claim 16, further comprising exposing the substrate to a pretreatment process, wherein the pretreatment process is performed after forming the second aperture and is adapted to remove an oxide layer from the exposed surface of the tungsten-containing contact plug.

20. The method of claim 17, further comprising removing the second dielectric layer from the surface of the tungsten-containing contact plug before depositing the first metal layer.

21. The method of claim 16, further comprising exposing the substrate to a pretreatment process, wherein the pretreatment process is adapted to remove an oxide layer from a surface of the exposed tungsten-containing contact plug before selectively filling the second aperture with the fill material.

22. The method of claim 16, wherein the pretreatment process further comprises exposing the substrate to a wet-clean solution having a pH value of less than about 5.

23. The method of claim 22, wherein wet-clean solution further comprises a complexing agent that is selected from the group consisting of citric acid, EDTA, EDA, carboxylic acids, amines, salts thereof, derivatives thereof and combinations thereof.

24. The method of claim 17, wherein the first metal layer is contains a metal selected from the group consisting of metallic nickel (Ni), metallic cobalt (Co), cobalt boride (CoB), cobalt phosphide (CoP), cobalt tungsten phosphide (CoWP), cobalt tungsten boride (CoWB), cobalt molybdenum phosphide (CoMoP), cobalt molybdenum boride (CoMoB), cobalt rhenium boride (CoReB), cobalt rhenium phosphide (CoReP), nickel boride (NiB), nickel phosphide (NiP), nickel tungsten phosphide (NiWP), nickel tungsten boride (NiWB), nickel molybdenum phosphide (NiMoB), nickel molybdenum phosphide (NiMoP), nickel rhenium phosphide (NiReP), and nickel rhenium boride (NiReB).

25. The method of claim 16, wherein the fill material is selected from the group consisting of metallic nickel (Ni), metallic cobalt (Co), cobalt boride (CoB), cobalt phosphide (CoP), cobalt tungsten phosphide (CoWP), cobalt tungsten boride (CoWB), cobalt molybdenum phosphide (CoMoP), cobalt molybdenum boride (CoMoB), cobalt rhenium boride (CoReB), cobalt rhenium phosphide (CoReP), nickel boride (NiB), nickel phosphide (NiP), nickel tungsten phosphide (NiWP), nickel tungsten boride (NiWB), nickel molybdenum phosphide (NiMoB), nickel molybdenum phosphide (NiMoP), nickel rhenium phosphide (NiReP), and nickel rhenium boride (NiReB).

26. The method of claim 16, wherein the fill material is electrolessly deposited on the exposed surface of the tungsten-containing contact plug and is generally in contact with the second dielectric layer.

27. The method of claim 26, wherein the fill material contains a metal selected from the group consisting of cobalt and nickel.

28. The method of claim 18, further comprising filing the exposed gap with a second layer that contains a metal selected from the group consisting of metallic nickel (Ni), metallic cobalt (Co), cobalt boride (CoB), cobalt phosphide (CoP), cobalt tungsten phosphide (CoWP), cobalt tungsten boride (CoWB), cobalt molybdenum phosphide (CoMoP), cobalt molybdenum boride (CoMoB), cobalt rhenium boride (CoReB), cobalt rhenium phosphide (CoReP), nickel boride (NiB), nickel phosphide (NiP), nickel tungsten phosphide (NiWP), nickel tungsten boride (NiWB), nickel molybdenum phosphide (NiMoB), nickel molybdenum phosphide (NiMoP), nickel rhenium phosphide (NiReP), and nickel rhenium boride (NiReB).

29. A method of forming an interconnect on a silicon substrate, comprising:

providing a substrate having an aperture formed in a dielectric layer disposed on a surface of the substrate, wherein the aperture is in communication with an exposed surface of a tungsten-containing contact plug;

dispensing a clean solution on an the exposed surface of the tungsten-containing contact plug, wherein the clean solution comprises hydrogen fluoride;

disposing a preparation solution on the exposed surface of the tungsten-containing contact plug, wherein the preparation solution comprises a tungstate source;

depositing a initiation layer on the exposed surface of the tungsten-containing contact plug using an activation solution; and

selectively filling the second aperture with a fill material.

30. The method of claim 29, wherein the clean solution is an aqueous solution that has a hydrofluoric acid concentration in a range from about 0.1 wt % to about 0.5 wt %.

31. The method of claim 29, wherein the preparation solution is an aqueous solution that comprises a tungstate source that is selected from the group consisting of ammonium tungsten oxide, tungstic acid, water soluble WO₄²⁻

sources, derivatives thereof and combinations thereof.

32. The method of claim 29, wherein the preparation solution is an aqueous solution that has a tungstic acid concentration in a range from about 2 mM to about 100 mM.

33. The method of claim 29, further comprising dispensing a chelating solution on the exposed surface of the substrate, wherein the chelating solution comprises citric acid that is in a concentration between about 50 mM and about 300 mM.

34. The method of claim 29, wherein the initiation layer is deposited using an activation solution that contains a palladium source.

35. The method of claim 29, wherein the fill material contains a metal selected from the group consisting of cobalt and nickel.

36. The method of claim 29, wherein the fill material contains a metal selected from the group consisting of metallic nickel (Ni), metallic cobalt (Co), cobalt boride (CoB), cobalt phosphide (CoP), cobalt tungsten phosphide (CoWP), cobalt tungsten boride (CoWB), cobalt molybdenum phosphide (CoMoP), cobalt molybdenum boride (CoMoB), cobalt rhenium boride (CoReB), cobalt rhenium phosphide (CoReP), nickel boride (NiB), nickel phosphide (NiP), nickel tungsten phosphide (NiWP), nickel tungsten boride (NiWB), nickel molybdenum phosphide (NiMoB), nickel molybdenum phosphide (NiMoP), nickel rhenium phosphide (NiReP), and nickel rhenium boride (NiReB).

37. The method of claim 29, further comprising activating the initiation layer using a rinse activation solution before selectively filling the second aperture with a fill material.

38. The method of claim 37, wherein rinse activation solution has a borane reductant concentration in a range from about 1 mM to about 200 mM.