Method for high kinetic energy plasma barrier deposition

• US 6,949,472 B1
• Filed: 05/03/2004
• Issued: 09/27/2005
• Est. Priority Date: 05/03/2004
• Status: Active Grant

• Current Assignee: Taiwan Semiconductor Manufacturing Company Limited
• Original Assignee: Taiwan Semiconductor Manufacturing Company Limited
• Inventors: Shue, Shau-Lin, Huang, Cheng-Lin, Hsieh, Ching-Hua
• Primary Examiner(s): Coleman, W. David
• Assistant Examiner(s): Yevsikov, Victor V.
• Application Number:
  US10/838,720
• Time in Patent Office: 512 Days
• Field of Search: 438/758, 438/694, 438/689, 438/643, 438/627, 438/653, 438/618
• US Class Current: 438/758
• CPC Class Codes: H01L 21/02046 Dry cleaning only H01L21/02085 takes precedence
• CPC Class Codes: H01L 21/2855 by physical means, e.g. sputtering, evaporation H01L21/28518 - H01L21/28537 and H01L21/28568 take precedence
• 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 21/76862 Bombardment with particles, e.g. treatment in noble gas plasmas; UV irradiation
• CPC Class Codes: H01L 21/76865 Selective removal of parts of the layer H01L21/76844 takes precedence

Abstract

A novel method for depositing a barrier layer on a single damascene, dual damascene or other contact opening structure. The method eliminates the need for pre-cleaning argon ion bombardment of the structure, thereby reducing or eliminating damage to the surface of the underlying conductive layer and sputtering of copper particles to the via or other contact opening sidewall. The process includes fabrication of a single damascene, dual damascene or other contact opening structure on a substrate; optionally pre-cleaning the structure typically using nitrogen or hydrogen plasma; depositing a thin metal barrier layer on the sidewalls and bottom of the structure; and redistributing or re-sputtering the barrier layer on the bottom and sidewalls of the structure.

Claims

1. A method of depositing a barrier layer to improve barrier layer thickness uniformity in an interconnect opening, comprising the steps of:

providing a substrate comprising a dielectric layer;

forming a structure comprising an interconnect opening in said dielectric layer;

initially forming a barrier layer to line said interconnect opening; and

,

re-distributing said barrier layer according to a sputter-redistribution process to increase said barrier layer thickness and thickness uniformity along said interconnect opening sidewalls.

2. The method of claim 1 further comprising the step of pre-cleaning said structure by subjecting said structure to a reactive plasma prior to the step of initially forming a barrier layer.

3. The method of claim 2, wherein said reactive plasma is formed from a plasma source gas selected from the group consisting of hydrogen (H₂) and nitrogen (N₂).

4. The method of claim 1 wherein said barrier layer has a substantially uniform thickness along said sidewalls of from about 10 angstroms to about 600 angstroms following the step of redistributing.

5. The method of claim 1 wherein said structure is a dual damascene structure.

6. The method of claim 1 wherein said barrier metal layer is initially formed by a high kinetic energy plasma sputter deposition process at an input power of at least about 80 watts per square inch of sputter target area.

7. The method of claim 1 wherein said barrier layer is initially formed having a non-uniform thickness along said sidewalls.

8. The method of claim 1, wherein said interconnect opening exposes a conductive portion at a bottom portion of said interconnect opening prior to the step of forming a barrier layer.

9. The method of claim 1, wherein following the step of redistributing, a thinned portion of said barrier layer remains covering a bottom portion of said interconnect opening.

10. The method of claim 1, further comprising the steps of:

forming a metal seed layer on the barrier layer following the step of redistributing; and

,

filling the interconnect opening with copper.

11. The method of claim 1, wherein the sputter-redistribution process comprises argon plasma bombardment.

12. The method of claim 1, wherein said barrier layer comprises a material selected from the group consisting of Ti, TiN, Ta, and TaN.

13. A method of forming a barrier layer to improve barrier layer thickness uniformity comprising the steps of:

providing a substrate comprising a dielectric layer overlying a conductive layer;

forming a structure comprising an interconnect opening in said dielectric layer to expose said conductive layer at a bottom portion of said interconnect opening;

forming a barrier layer to line said interconnect opening, said barrier layer comprising a non-uniform thickness along sidewall portions; and

,

re-distributing said barrier layer according to a sputter-redistribution process to increase said barrier layer thickness and thickness uniformity along said interconnect opening sidewalls.

14. The method of claim 13 further comprising the step of pre-cleaning said structure by subjecting said structure to a reactive plasma prior to the step of forming a barrier layer.

15. The method of claim 13 wherein said barrier layer has a substantially uniform thickness along said sidewall portions following the step of redistributing.

16. The method of claim 13 wherein said structure is a dual damascene structure.

17. A method of depositing a barrier layer to improve metal seed layer formation comprising the steps of:

providing a substrate comprising a dielectric layer overlying a conductive layer;

forming a structure comprising an interconnect opening in said dielectric layer to expose said conductive layer at a bottom portion of said interconnect opening;

forming a barrier layer to line said interconnect opening, said barrier layer comprising a non-uniform thickness along sidewall portions;

re-distributing said barrier layer according to a sputter-redistribution process to increase said barrier layer thickness and thickness uniformity along said interconnect opening sidewalls while leaving a portion of said barrier layer covering said bottom portion; and

,

then forming a metal seed layer on said barrier layer.

18. The method of claim 17 further comprising the step of pre-cleaning said interconnect opening by subjecting said structure to a reactive plasma prior to the step of forming a barrier layer.

19. The method of claim 17 wherein said barrier layer has a substantially uniform thickness along said sidewall portions and said bottom portion of from about 10 angstroms to about 600 angstroms following the step of redistributing.

20. The method of claim 17 wherein said structure is selected from the group consisting of a single damascene and a dual damascene structure.