Method for fabricating low resistivity barrier for copper interconnect

• US 20050277292A1
• Filed: 05/28/2004
• Published: 12/15/2005
• Est. Priority Date: 05/28/2004
• Status: Abandoned Application

• Current Assignee: Taiwan Semiconductor Manufacturing Company Limited
• Original Assignee: Taiwan Semiconductor Manufacturing Company Limited
• Inventors: Shue, Shau-Lin, Hsieh, Ching-Hua, Peng, Chao-Hsien
• Application Number:
  US10/856,899
• Publication Number:
  US 20050277292A1
• Time in Patent Office: Days
• US Class Current: 438/672
• CPC Class Codes: H01L 21/28562 Selective deposition
• CPC Class Codes: H01L 21/76843 formed in openings in a dielectric
• CPC Class Codes: H01L 21/76856 by treatment in plasmas or gaseous environments, e.g. nitriding a refractory metal liner
• CPC Class Codes: H01L 21/76862 Bombardment with particles, e.g. treatment in noble gas plasmas; UV irradiation

Abstract

A method of reducing the sheet resistivity of an ALD-TaN layer in an interconnect structure. The ALD-TaN layer is treated with a plasma treatment, such as Argon or Tantalum plasma treatment, to increase the Ta/N ratio of the ALD-TaN barrier layer, thereby reducing the sheet resistivity of the ALD-TaN layer.

Claims

1. A method for forming an interconnect structure, comprising:

forming a dielectric layer overlying a substrate;

forming an opening in the dielectric layer;

forming a barrier layer lining the opening by atomic layer deposition (ALD);

performing a tantalum (Ta) plasma treatment on the ALD-barrier layer; and

filling the opening with a conductive layer.

2. The method of as claimed in claim 1, wherein the ALD-barrier layer is an ALD-TaN layer.

3. The method of as claimed in claim 1, wherein the plasma treatment is a plasma treatment with a tantalum metal-coating target.

4. The method of as claimed in claim 3, wherein the tantalum plasma treatment utilizes an inert gas as a source gas.

5. The method as claimed in claim 1, further comprising:

forming a tantalum layer on the surface of the treated ALD-TaN layer before filling the opening with the conductive layer.

6. The method as claimed in claim 1, wherein the dielectric layer comprises a low-k material with a dielectric constant k<

3.2.

7. A method for forming a barrier layer in an interconnect opening, comprising:

forming an opening in a substrate;

forming a TaN layer on the substrate and lining the opening by atomic layer deposition (ALD); and

increasing Ta/N ratio of the ALD-TaN layer by performing a tantalum plasma treatment.

8. The method as claimed in claim 7, wherein the Ta/N ratio is increased by performing a plasma treatment with a tantalum metal-coating target on the ALD-TaN layer.

10. The method as claimed in claim 8, further comprising:

forming a tantalum layer with increased Ta/N ratio on the surface of the TaN layer.

9. (canceled)

11. A method for reducing resistivity of transition metallic nitride formed by atomic layer deposition (ALD), comprising:

forming a transition metallic nitride layer by atomic layer deposition (ALD); and

performing a transition metallic plasma treatment on the ALD-transition metallic nitride layer to increase transition metal-nitrogen ration thereof.

12. The method of as claimed in claim 11, wherein the plasma treatment is a plasma treatment with the same transition metal.

13. The method as claimed in claim 11, wherein the transition metallic nitride layer is a TaN layer or TiN layer.

14. A method for adjusting element ratio of a binary compound composed of a first element and a second element, formed by atomic layer deposition (ALD), comprising:

forming the binary compound layer by atomic layer deposition (ALD); and

performing a transition metallic plasma treatment on the ALD-binary compound layer to increase the first element/the second ratio thereof.

15. The method as claimed in claim 14, wherein the binary compound is TaN and the first and second elements are Ta and N respectively.

16. The method of as claimed in claim 15, wherein the plasma treatment is a plasma treatment with the first element.

17-20. -20. (canceled)