Metallized oxide structure and fabrication

• US 5,926,360 A
• Filed: 02/27/1997
• Issued: 07/20/1999
• Est. Priority Date: 12/11/1996
• Status: Expired due to Fees

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: Shaw, Thomas McCarroll, Laibowitz, Robert Benjamin, Viggiano, Joseph M.
• Primary Examiner(s): Ledynh, Bot L.
• Assistant Examiner(s): Dinkins, Anthony
• Application Number:
  US08/807,186
• Time in Patent Office: 873 Days
• Field of Search: 361/303, 361/305, 361/306.3, 361/311, 361/312, 361/313, 361/321.1, 361/321.2, 361/321.3, 361/321.4, 361/321.5, 361/322, 29/25.42, 205/123, 427/123, 427/126.3, 427/126.4, 427/126.5, 257/303, 257/295, 257/306, 257/307, 257/308, 257/309, 257/310
• US Class Current: 361/321.4
• CPC Class Codes: H01G 4/008 Selection of materials

Abstract

A structure for providing an interface with an oxide surface which exhibits both high adhesion and preferred electrical properties. An embodiment includes a capacitor structure having one or two electrodes abutting a high dielectric thin film, whereby the electrodes comprise first partial layers of metal having favorable electrical properties and second continuous layers adjacent the first partial layers, with the second layer material having been chosen for its physical properties, and wherein the second material adheres to exposed areas of the thin film through openings in the partial metal layer.

Claims

1. An adherent metal electrode structure comprising:

an oxide material having a surface;

a metal layer contacting said surface of said oxide material, said metal layer selected for providing an abrupt electrical interface with said oxide material, said metal layer having openings exposing areas of said surface of said oxide material; and

a layer of material contacting said metal layer and said exposed areas of said surface of said oxide material, said material for said layer of material selected to adhere to said oxide material whereby no interfacial layer forms between said areas of said surface of said oxide material exposed in said openings of said metal layer and said metal layer and whereby an interfacial layer forms between said areas of said surface of said oxide material exposed in said openings of said metal layer and said material for said layer of material.

2. The electrode structure of claim 1 wherein said oxide material is selected from the group consisting of barium titanate, strontium titanate, lead zirconium titanate, barium strontium titanate, lead lanthanum titanate, lead lanthanum zirconium titanate, lead manganese titanate with lead titanate lead magnesium niobate with lead titanate, and other niobates, manganates and tantalates.

3. The electrode structure of claim 1 wherein said oxide material is a conducting oxide selected from the group consisting of InO₂, SnO₂, RuO₂, SrRuO₂ and YBCO.

4. The electrode structure of claim 1 wherein the thickness of said metal layer is greater than the thickness at which said metal layer becomes conducting.

5. The electrode structure of claim 4 wherein said metal layer has a thickness of less than 20 nm.

6. The electrode structure of claim 1 wherein said metal layer is in the range of 125 to 180 Å

.

7. The electrode structure of claim 1 wherein said metal layer comprises metal selected from the group consisting of Pt, Pd, Au, Ag, Rh, Re, Tr, Os and Ru.

8. The electrode structure of claim 7 wherein the thickness of said metal layer is greater than the thickness at which said metal layer becomes conducting.

9. The electrode structure of claim 7 wherein said metal has a thickness of less than 20 nm.

10. The electrode structure of claim 7 wherein said metal layer is in the range of 125 to 180 Å

.

11. The electrode structure of claim 7 wherein said oxide material is selected from the group consisting of barium titanate, strontium titanate, lead zirconium titanate, barium strontium titanate, lead lanthanum titanate, lead lanthanum zirconium titanate, lead manganese titanate with lead titanate, lead magnesium niobate with lead titanate, and other niobates, manganates and tantalates.

12. The electrode structure of claim 7 wherein said oxide material is a conducting oxide selected from the group consisting of InO₂, SnO₂, RuO₂, SrRuO₂ and YBCO.

13. The electrode structure of claim 1 wherein said layer of material comprises material selected from the group consisting of Al, Cu, Ta, Ti, Nb, Ni, Mo, MoW, Sn, alloys of those metals, conducting oxides, conducting silicides and conducting nitrides.

14. The electrode structure of claim 7 wherein said layer of material comprises material selected from the group consisting of Al, Cu, Ta, Ti, Nb, Ni, Mo, MoW, Sn, alloys of those metals, conducting oxides, conducting silicides and conducting nitrides.

15. The electrode structure of claim 11 wherein said layer of material comprises material selected from the group consisting of Al, Cu, Ta, Ti, Nb, Ni, Mo, MoW, Sn, alloys of those metals, conducting oxides, conducting suicides and conducting nitrides.

16. The electrode structure of claim 12 wherein said layer of material comprises material selected from the group consisting of Al, Cu, Ta, Ti, Nb, Ni, Mo, MoW, Sn, alloys of those metals, conducting oxides, conducting silicides and conducting nitrides.

17. A capacitor structure on a substrate comprising:

a first layer of conducting material deposited on said substrate;

a partial first metal layer deposited on said first layer of conducting material, said partial first layer having openings exposing areas of the said conducting material;

a thin film of high permittivity material overlaying said partial first layer and said areas of said conducting material;

a partial second metal layer deposited on said thin film, said partial second metal layer having second openings exposing areas of said thin film; and

a second layer of conducting material overlaying said partial second layer and said exposed areas of thin film.

18. The capacitor structure of claim 17 wherein said first and said second conducting materials are materials selected to adhere to said high permittivity material.

19. The capacitor structure of claim 18 wherein said first and said second conducting materials are layer of selected from the group consisting of Al, Cu, Ta, Ti, Nb, Ni, Mo, MoW, Sn, alloys of those metals, conducting oxides, conducting silicides and conducting nitrides.

20. The capacitor structure of claim 17 wherein metal for said partial first and said partial second metal layers is selected to provide an abrupt electrical interface with said high permittivity material.

21. The capacitor structure of claim 20 wherein said metal is selected from the group consisting of Pt, Pd, Au, Ag, Rh, Re, Tr, Os and Ru.

22. The capacitor structure of claim 19 wherein metal for said partial first and said partial second metal layers is selected to provide an abrupt electrical interface with said high permittivity material.

23. The capacitor structure of claim 22 wherein said metal is selected from the group consisting of Pt, Pd, Au, Ag, Rh, Re, Ir, Os and Ru.

24. The capacitor structure of claim 17 wherein said high permittivity material is selected from the group consisting of barium titanate, strontium titanate, lead zirconium titanate, barium strontium titanate, lead lanthanum titanate, lead lanthanum zirconium titanate, lead manganese titanate with lead titanate, lead magnesium niobate with lead titanate, and other niobates, manganates and tantalates.

25. The capacitor structure of claim 23 wherein said high permittivity material is selected from the group consisting of barium titanate, strontium titanate, lead zirconium titanate, barium strontium titanate, lead lanthanum titanate, lead lanthanum zirconium titanate, lead manganese titanate with lead titanate, lead magnesium niobate with lead titanate, and other niobates, manganates and tantalates.

26. The capacitor structure of claim 17 wherein said partial first and said partial second metal layers have thicknesses greater than the thicknesses at which said metal layers become conducting.

27. The capacitor structure of claim 17 wherein said partial first and said partial second metal layers have thicknesses in the range of 125 to 180 Å

.

28. The capacitor structure of claim 25 wherein said partial first and said partial second metal layers have thicknesses greater than the thicknesses at which said metal layers become conducting.

29. The capacitor structure of claim 25 wherein said partial first and said partial second metal layers have thicknesses in the range of 125 to 180 Å

.