Contact metallization scheme using a barrier layer over a silicide layer

• US 20060251800A1
• Filed: 03/20/2006
• Published: 11/09/2006
• Est. Priority Date: 03/18/2005
• Status: Active Grant

• Current Assignee: Applied Materials Incorporated
• Original Assignee: Applied Materials Incorporated
• Inventors: Weidman, Timothy W., Shanmugasundram, Arulkumar, Mei, Fang, Khandelwal, Amit, Wijekoon, Kapila P., Yang, Michael X., Zhu, Zhize, Moghadam, Farhad K., Gelatos, Avgerinos V. (Jerry)
• Granted Patent: US 7,514,353 B2
• Time in Patent Office: Days
• US Class Current: 427/99.500
• 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

Embodiments of the invention generally provide methods of filling contact level features formed in a semiconductor device by depositing a barrier layer over the contact feature and then filing the layer using an PVD, CVD, ALD, electrochemical plating process (ECP) and/or electroless deposition processes. In one embodiment, the barrier layer has a catalytically active surface that will allow the electroless deposition of a metal on the barrier layer. In one aspect, the electrolessly deposited metal is copper or a copper alloy. In one aspect, the contact level feature is filled with a copper alloy by use of an electroless deposition process. In another aspect, a copper alloy is used to from a thin conductive copper layer that is used to subsequently fill features with a copper containing material by use of an ECP, PVD, CVD, and/or ALD deposition process. In one embodiment, a portion of the barrier layer is purposely allowed to react with traces of residual oxide at the silicon junction of the contact level feature to form a low resistance connection.

Claims

1. A method for depositing a material on a contact level feature formed on a substrate, comprising:

providing a substrate that has one or more contact level features that have an exposed suicide layer formed on a silicon containing region;

depositing a barrier layer over the surface of the exposed suicide layer, wherein the depositing the barrier layer comprises;

depositing a first metal layer on the exposed silicide layer; and

depositing a second metal layer over the first metal layer, wherein the second metal layer contains a metal selected from a group consisting of ruthenium (Ru), cobalt (Co), nickel (Ni), rhodium (Rh), iridium (Ir), palladium (Pd) and platinum (Pt); and

filling the contact level feature with a metal containing layer.

2. The method of claim 1, further comprising electrolessly depositing a third metal layer on the doped silicon containing region prior to providing the substrate, wherein the third metal layer is used to form at least a portion of the exposed silicide layer.

3. The method of claim 2, further comprising heating the substrate to a temperature that causes an element in the third metal layer to form at least a portion of the exposed silicide layer on the silicon containing region.

4. The method of claim 1, further comprising depositing a cobalt containing layer on the exposed silicide layer, wherein the exposed silicide layer comprises a nickel silicide.

5. The method of claim 4, wherein the thickness of the cobalt containing layer is between about 5 angstroms and about 50 angstroms.

6. The method of claim 2, wherein the third metal layer contains an element selected from a group consisting of titanium (Ti), cobalt (Co), nickel (Ni), tungsten (W), molybdenum (Mo), and tantalum (Ta).

7. The method of claim 1, wherein the thickness of the barrier layer deposited on the on the exposed silicide layer is between about 10 angstroms and about 100 angstroms.

8. The method of claim 2, wherein the thickness of the third metal layer deposited on the on the doped silicon containing region is between about 5 angstroms and about 50 angstroms.

9. The method of claim 1, wherein the barrier layer deposited on the exposed silicide layer has a resistivity less than about 10×

10<sup>−

6</sup> ohm-cm.

10. The method of claim 1, wherein the metal containing layer is a copper containing layer.

11. The method of claim 10, wherein the copper containing layer comprises copper and aluminum, wherein the copper containing layer is deposited using an electroless solution that contains about 7 grams/liter of a copper ion source and between about 0.5 and about 6 grams/liter of an aluminum ion source.

12. The method of claim 10, wherein the metal containing layer further comprises copper and an element selected from a group consisting of aluminum (Al), indium (In), molybdenum (Mo), tungsten (W), manganese (Mn), cobalt (Co), palladium (Pd), nickel (Ni), tin (Sn), and ruthenium (Ru).

13. The method of claim 1, wherein the first metal layer contains an element selected from a group consisting of titanium (Ti), cobalt (Co), nickel (Ni), tungsten (W), molybdenum (Mo), nitrogen (N), and tantalum (Ta).

14. The method of claim 1, wherein the second metal layer comprises ruthenium and tantalum.

15. The method of claim 14, wherein the second metal layer comprises between about 70% and about 95% ruthenium and the balance tantalum.

16. The method of claim 1, further comprising depositing a third metal layer on the first metal layer prior to depositing the second metal layer.

17. The method of claim 16, wherein the first metal layer is a titanium containing layer, the third metal layer is a titanium nitride containing layer and the second metal layer is a ruthenium containing layer.

18. The method of claim 1, wherein the metal containing layer is a copper containing layer that is deposited by an electrochemical deposition process.

19. A method for depositing a material on a contact level feature formed on a substrate, comprising:

providing a substrate that has one or more contact level features that have an exposed silicide layer formed on a doped silicon containing region;

depositing a barrier layer over the surface of the exposed silicide layer, wherein the depositing the barrier layer comprises;

depositing a first metal layer on the exposed silicide layer; and

depositing a second metal layer over the first metal layer, wherein the second metal layer contains a metal selected from a group consisting of ruthenium (Ru), cobalt (Co), nickel (Ni), rhodium (Rh), iridium (Ir), palladium (Pd) and platinum (Pt);

electrolessly depositing a first copper containing layer on the barrier layer; and

depositing a second copper containing layer on the first copper containing layer to fill the one or more contact level features.

20. The method of claim 19, wherein the second copper containing layer is generally pure copper layer deposited using an electrochemical deposition process.

21. The method of claim 19, wherein the first copper containing layer comprises copper and an element selected from a group consisting of aluminum (Al), indium (In), molybdenum (Mo), tungsten (W), manganese (Mn), cobalt (Co), palladium (Pd), nickel (Ni), tin (Sn), and ruthenium (Ru).

22. The method of claim 19, further comprising depositing a third metal layer on the first metal layer prior to depositing the second metal layer.

23. The method of claim 22, wherein the first metal layer is a titanium containing layer, the third metal layer is a titanium nitride containing layer and the second metal layer is a ruthenium containing layer.

24. The method of claim 19, wherein the second copper containing layer is deposited by an electrochemical deposition process.

25. A method for depositing a material on a contact level feature formed on a substrate, comprising:

depositing a barrier layer over the surfaces of one or more contact level features formed on the substrate; and

electrolessly depositing a copper containing layer on the barrier layer using a metal layer electroless deposition solution, wherein the metal layer electroless deposition solution comprises EDTA and copper ions at a concentration ratio of less than about 6;

1.

26. A method for depositing a material on a contact level feature formed on a substrate, comprising:

electrolessly depositing a first metal containing layer on a doped silicon region on a surface of a substrate;

forming a contact level interconnect feature, wherein the process of forming the contact level interconnect comprises;

depositing a dielectric layer over a surface of the substrate and the first metal containing layer; and

forming one or more contact level features in the dielectric layer using conventional semiconductor processing methods, wherein the first metal containing layer is exposed at the bottom of one or more of the contact level features;

depositing a barrier layer over the surface of the first metal layer, wherein the depositing the barrier layer comprises;

depositing a second metal layer over the first metal layer, wherein the second metal layer contains a metal selected from a group consisting of ruthenium (Ru), cobalt (Co), nickel (Ni), rhodium (Rh), iridium (Ir), palladium (Pd) and platinum (Pt); and

electrolessly depositing a copper containing layer on the barrier layer.

27. The method of claim 26, wherein the first metal containing layer comprises an element selected from a group consisting of cobalt (Co) and nickel (Ni).

28. The method of claim 26, further comprising depositing a cobalt containing layer on the first metal containing layer, wherein the first metal containing layer comprises a nickel containing alloy.

29. The method of claim 28, further comprising heating the substrate to a temperature that causes the nickel containing layer to form a nickel silicide.

30. The method of claim 26, further comprising depositing a third metal layer on the first metal layer before depositing the second metal over the first metal layer.

31. The method of claim 30, wherein the third metal layer contains a metal selected from a group consisting of titanium (Ti), tantalum (Ta), tungsten (W), ruthenium (Ru), cobalt (Co), and nickel (Ni).

32. A method for depositing a material on a contact level feature formed on a substrate, comprising:

providing a substrate that has one or more contact level features that have an exposed doped silicon containing region;

depositing a first metal layer on the doped silicon containing region;

depositing a barrier layer over the surface of the first metal layer, wherein the depositing the barrier layer comprises;

depositing a second layer over the first layer, wherein the second layer comprises ruthenium and tantalum; and

filling the contact level feature with a metal containing layer.

33. The method of claim 32, wherein the barrier layer further comprises depositing a third layer on the first metal layer prior to depositing the second layer.

34. The method of claim 33, wherein the third layer contains a metal selected from a group consisting of titanium (Ti), tantalum (Ta), tungsten (W), ruthenium (Ru), cobalt (Co), nickel (Ni), rhodium (Rh), iridium (Ir), palladium (Pd) and platinum (Pt).

35. The method of claim 32, wherein the metal containing layer comprises copper.