Method of enhancing adhesion of a conductive barrier layer to an underlying conductive plug and contact for ferroelectric applications

• US 6,576,546 B2
• Filed: 12/19/2000
• Issued: 06/10/2003
• Est. Priority Date: 12/22/1999
• Status: Expired due to Term

• Current Assignee: Broadcom International Pte Ltd. (Broadcom, Inc.), Texas Instruments, Inc.
• Original Assignee: Agilent Technologies, Inc., Texas Instruments, Inc.
• Inventors: Colombo, Luigi, Summerfelt, Scott, Gilbert, Stephen R.
• Primary Examiner(s): Zarabian, Amir
• Assistant Examiner(s): GUERRERO, MARIA F
• Application Number:
  US09/741,677
• Publication Number:
  US 20020072223A1
• Time in Patent Office: 903 Days
• Field of Search: 438/618, 438/622, 438/624, 438/627, 438/628, 438/629, 438/637, 438/643, 438/644, 438/648, 438/652, 438/653, 438/654, 438/672, 438/685
• US Class Current: 438/629
• CPC Class Codes: H01L 21/32051 Deposition of metallic or metal-silicide layers
• CPC Class Codes: H01L 21/76802 by forming openings in dielectrics
• 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 21/76826 by contacting the layer with gases, liquids or plasmas
• CPC Class Codes: H01L 21/76828 thermal treatment
• CPC Class Codes: H01L 21/76832 Multiple layers
• 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 21/7687 Thin films associated with contacts of capacitors
• CPC Class Codes: H01L 21/76877 Filling of holes, grooves or trenches, e.g. vias, with conductive material
• CPC Class Codes: H01L 21/76889 by forming silicides of refractory metals
• CPC Class Codes: H01L 28/75 comprising two or more layers, e.g. comprising a barrier layer and a metal layer

Abstract

An embodiment of the instant invention is a method of forming a conductive barrier layer on a dielectric layer, the method comprising the steps of: providing the dielectric layer (112 of FIG. 7d) having a top surface, a bottom surface, and an opening extending from the top surface to the bottom surface, and including a conductive plug (704 of FIG. 7d) having a top surface substantially coplanar with the top surface of the dielectric layer; subjecting the top surface of the dielectric layer and the top surface of the conductive plug to a gas selected from the group consisting of: argon, nitrogen, hydrogen, CH₄, and any combination thereof, the gas being incorporated into a high-temperature ambient or a plasma; and forming the conductive barrier layer on the top surface of the dielectric layer and the top surface of the conductive plug after the step of subjecting the top surface of the dielectric layer and the top surface of the conductive plug to the gas incorporated into the high-temperature ambient or the plasma.

Claims

1. A method of forming a conductive barrier layer on a dielectric layer, said meted comprising the steps of:

providing the dielectric layer having a top surface, a bottom surface, and an opening extending from the top surface to the bottom surface, and including a conductive plug having a top surface substantially coplanar with said top surface of said dielectric layer;

subjecting said top surface of said dielectric layer and said top surface of said conductive plug to a gas selected from the group consisting of;

argon, nitrogen, hydrogen, CH₄, and any combination thereof, said gas being incorporated into a high-temperature ambient or a plasma; and

depositing said conductive barrier layer on said top surface of said dielectric layer and said top surface of said conductive plug after said step of subjecting said top surface of said dielectric layer and said top surface of said conductive plug to said gas incorporated into said high-temperature ambient or said plasma.

2. The method of claim 1, wherein said high temperature is around 500 to 1000 C.

3. The method of claim 1, wherein said high temperature is around 600 to 750 C.

4. The method of claim 1, wherein said conductive barrier layer is comprised of a conductor selected from the group consisting of:

TiAlN, TiSiN, TaN, TiN, CrN, CrAlN, TaSiN, ZrN, HfN, and any combination thereof.

5. The method of claim 1, wherein said conductive plug is comprised of tungsten.

6. The method of claim 1, wherein said gas is comprised of nitrogen and hydrogen.

7. The method of claim 1, wherein said gas is comprised of argon and hydrogen.

8. The method of claim 5, wherein said step of subjecting said top surface of said dielectric layer and said top surface of said conductive plug to said gas incorporated into said high-temperature ambient or said plasma removes any oxide formed on said tungsten plug.

9. The method of claim 1, further comprising:

before the subjecting step, exposing the top surface of the dielectric layer to a low-temperature oxygen plasma.

10. The method of claim 1, wherein the step of providing the dielectric layer including the conductive plug comprises:

forming the dielectric layer over a semiconducting surface of a substrate;

patterning and etching a selected location of the dielectric layer to form an opening therethrough;

filling the opening with a conductive material; and

planarizing the dielectric layer and the conductive material by chemical mechanical polishing, to form the conductive plug from the conductive material.

11. The method of claim 1, further comprising:

after the depositing step, forming a ferroelectric capacitor having a plate in contact with the conductive plug.

12. A method of forming a conductive baffler layer on a dielectric layer, said method comprising the steps of:

forming a dielectric layer over a semiconducting surface of a substrate;

etching a selected location of the dielectric layer to form an opening therethrough;

filling the opening with a conductive material; and

planarizing the dielectric layer and the conductive material by chemical mechanical polishing, to form a conductive plug from the conductive material, the conductive plug having a top surface substantially coplanar with a top surface of the dielectric layer;

annealing the top surface of said dielectric layer and the top surface of said conductive plug at a high temperature; and

depositing the conductive barrier layer on the top surface of the dielectric layer and the top surface of the conductive plug after the annealing step.

13. The method of claim 12, wherein the annealing step is performed in a vacuum.

14. The method of claim 12, wherein the annealing step is performed in an inert ambient.

15. The method of claim 12, wherein the annealing step is performed in an ambient comprised of a mixture of an inert gas and a reducing gas.

16. The method of claim 12, wherein the annealing step is performed in an ambient comprised of a reducing gas.

17. The method of claim 12, further comprising:

after the depositing step, forming a ferroelectric capacitor having a plate in contact with the conductive plug.

18. The method of claim 12, further comprising:

before the annealing step, exposing the top surface of the dielectric layer to a low-temperature oxygen plasma.

19. The method of claim 12, further comprising:

before the depositing step, exposing the top surface of the dielectric layer and the top surface of the conductive plug to a plasma.

20. The method of claim 19, wherein the plasma incorporates a reducing gas.

21. The method of claim 19, wherein the plasma incorporates an inert gas.

22. The method of claim 21, wherein the plasma also incorporates a reducing gas.

23. A method of forming a conductive baffler layer on a dielectric layer, said method comprising the steps of:

forming a dielectric layer over a semiconducting surface of a substrate;

etching a selected location of the dielectric layer to form an opening therethrough;

filling the opening with a conductive material; and

planarizing the dielectric layer and the conductive material by chemical mechanical polishing, to form a conductive plug from the conductive material, the conductive plug having a top surface substantially coplanar with a top surface of the dielectric layer;

after the planarizing step, exposing the top surface of the dielectric layer and the top surface of the conductive plug to a plasma; and

depositing the conductive baffler layer on the top surface of the dielectric layer and the top surface of the conductive plug after the exposing step.

24. The method of claim 23, wherein the plasma incorporates a reducing gas.

25. The method of claim 23, further comprising:

after the depositing step, forming a ferroelectric capacitor having a plate in contact with the conductive plug.

26. The method of claim 23, further comprising:

before the exposing step, exposing the top surface of the dielectric layer to a low-temperature oxygen plasma.

27. The method of claim 23, wherein the plasma incorporates an inert gas.

28. The method of claim 27, wherein the plasma also incorporates a reducing gas.