METHOD OF FORMING A METAL LAYER OVER A PATTERNED DIELECTRIC BY ELECTROLESS DEPOSITION USING A SELECTIVELY PROVIDED ACTIVATION LAYER

• US 20080182409A1
• Filed: 07/25/2007
• Published: 07/31/2008
• Est. Priority Date: 01/31/2007
• Status: Abandoned Application

• Current Assignee: GlobalFoundries, Inc.
• Original Assignee: GlobalFoundries, Inc.
• Inventors: Richter, Ralf, Seidel, Robert, Preusse, Axel
• Application Number:
  US11/782,987
• Publication Number:
  US 20080182409A1
• Time in Patent Office: Days
• US Class Current: 438/678
• CPC Class Codes: H01L 21/76843 formed in openings in a dielectric
• CPC Class Codes: H01L 21/76844 Bottomless liners
• CPC Class Codes: H01L 21/76849 the layer being positioned on top of the main fill metal
• CPC Class Codes: H01L 21/76859 by ion implantation
• CPC Class Codes: H01L 21/76865 Selective removal of parts of the layer H01L21/76844 takes precedence
• 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 21/76874 for electroless plating
• 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

Abstract

By forming an activation/nucleation layer selectively at a bottom of an opening, efficient electroless deposition techniques may be used for forming contacts, vias and trenches of advanced semiconductor devices. By selectively providing the activation material, a self-aligned bottom-to-top fill behavior may be obtained.

Claims

1. A method, comprising:

providing an exposed surface of an activation layer selectively at a bottom of an opening formed in a material layer of a semiconductor device, said activation layer comprising a species for initiating an electrochemical deposition process when being in contact with a specified electrolyte solution; and

applying said specified electrolyte solution in said opening to perform an electrochemical process for filling said opening with a conductive material from bottom to top on the basis of said exposed surface of the activation layer.

2. The method of claim 1, wherein providing said exposed surface of the activation layer comprises forming said opening and forming said activation layer in said opening.

3. The method of claim 2, wherein said activation layer is formed by a method that comprises forming said activation layer on exposed surfaces of said opening and covering sidewalls of said activation layer by a spacer material exhibiting a substantially inert behavior during the electrochemical process.

4. The method of claim 2, further comprising removing excess material of said activation layer outside said opening.

5. The method of claim 2, wherein said activation layer is formed by a selective deposition technique having a reduced deposition rate at sidewall surfaces of said opening compared to the bottom of said opening.

6. The method of claim 5, further comprising performing an etch process for removing material of said activation layer at the sidewalls of said opening.

7. The method of claim 1, wherein providing said exposed surface of the activation layer comprises forming said activation layer locally on a restricted device region of said semiconductor device, forming said material layer and forming said opening above said restricted device region to expose a portion of said activation layer.

8. The method of claim 7, wherein said restricted device region comprises a metal line of a metallization layer.

9. The method of claim 1, wherein said activation layer comprises at least one of platinum, palladium, silver, copper and cobalt.

10. The method of claim 1, wherein said specified electrolyte solution comprises at least one of copper, cobalt, nickel, silver, gold and alloys of any of these metals.

11. A method comprising:

forming an opening in a material layer of a semiconductor device;

providing an exposed catalyst material selectively at a bottom of said opening, said catalyst material initiating an electrochemical reaction upon contact with a specified electrolyte solution; and

filling said opening from bottom to top with a metal-containing material by applying said specified electrolyte solution.

12. The method of claim 11, wherein said catalyst material is provided in said opening by a directional ion bombardment.

13. The method of claim 12, wherein said directional ion bombardment comprises at least one of an ion implantation process and an ionized physical vapor deposition process.

14. The method of claim 11, wherein providing said catalyst material comprises forming an activation layer comprising said catalyst material on exposed surfaces of said opening.

15. The method of claim 14, further comprising covering sidewalls of said opening by a spacer layer after forming said activation layer.

16. The method of claim 14, further comprising removing said activation layer from sidewalls of said opening while covering the bottom of said opening to reduce material removal of said activation layer at the bottom.

17. The method of claim 11, wherein said metal-containing material comprises at least one of copper, cobalt, nickel, silver, gold and alloys of any of these metals.

18. A method, comprising:

forming an activation layer on a restricted area of a semiconductor device;

forming a dielectric layer above said restricted area;

forming an opening in said dielectric layer to expose a portion of said activation layer; and

filling said opening by an electrochemical deposition process using said exposed portion of the activation layer for initiating said electrochemical deposition process.

19. The method of claim 18, wherein said restricted area represents one of a metal region of a metallization layer and a contact area of a transistor element.

20. The method of claim 18, further comprising forming a conductive barrier layer on sidewalls of said opening prior to filling said opening by said electrochemical deposition process.