Schemes for Forming Barrier Layers for Copper in Interconnect Structures

• US 20190311993A1
• Filed: 06/24/2019
• Published: 10/10/2019
• Est. Priority Date: 11/21/2006
• Status: Active Grant

• Current Assignee: Taiwan Semiconductor Manufacturing Company Limited
• Original Assignee: Taiwan Semiconductor Manufacturing Company Limited
• Inventors: Yu, Chen-Hua, Chen, Hai-Ching, Bao, Tien-I
• Granted Patent: US 10,943,867 B2
• Time in Patent Office: Days
• CPC Class Codes: H01L 21/322 to modify their internal properties, e.g. to produce internal imperfections
• CPC Class Codes: H01L 21/76843 formed in openings in a dielectric
• CPC Class Codes: H01L 21/76849 the layer being positioned on top of the main fill metal
• 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 21/76877 Filling of holes, grooves or trenches, e.g. vias, with conductive material
• CPC Class Codes: H01L 21/76883 Post-treatment or after-treatment of the conductive material
• CPC Class Codes: H01L 23/528 Geometry or layout of the interconnection structure H01L27/0207 takes precedence; algorithms G06F30/00
• CPC Class Codes: H01L 23/53238 Additional layers associated with copper layers, e.g. adhesion, barrier, cladding layers
• CPC Class Codes: H01L 2924/00 Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
• CPC Class Codes: H01L 2924/0002 Not covered by any one of groups H01L24/00, H01L24/00 and H01L2224/00

Abstract

A method of forming a semiconductor structure includes providing a substrate; forming a low-k dielectric layer over the substrate; embedding a conductive wiring into the low-k dielectric layer; and thermal soaking the conductive wiring in a carbon-containing silane-based chemical to form a barrier layer on the conductive wiring. A lining barrier layer is formed in the opening for embedding the conductive wiring. The lining barrier layer may comprise same materials as the barrier layer, and the lining barrier layer may be recessed before forming the barrier layer and may contain a metal that can be silicided.

Claims

1. A method comprising:

forming a low-k dielectric layer over a substrate;

embedding a conductive wiring in the low-k dielectric layer; and

thermal soaking the conductive wiring in a gas with SiH-bonds to form a barrier layer on the conductive wiring, wherein the thermal soaking occurs in a non-plasma environment, the barrier layer comprising a silicide.

2. The method of claim 1, further comprising performing a decontamination process prior to the thermal soaking the conductive wiring.

3. The method of claim 2, wherein the decontamination process is performed at least in part in a hydrogen-based gas environment.

4. The method of claim 1, further comprising passivating the barrier layer after the thermal soaking the conductive wiring.

5. The method of claim 4, wherein the passivating the barrier layer is performed at least in part with a plasma treatment.

6. The method of claim 5, wherein the passivating the barrier layer is performed with a carbon-containing gas.

7. A method comprising:

embedding a conductive material in a low-k dielectric layer, the conductive material comprising a first element;

thermal soaking the conductive material in a gas with SiH-bonds to form a barrier layer on the conductive material, wherein the thermal soaking occurs in a non-plasma environment, and wherein the barrier layer comprises a silicide of the first element; and

performing a plasma process to passivate the barrier layer.

8. The method of claim 7, further comprising performing a decontamination process prior to the thermal soaking the conductive material.

9. The method of claim 8, wherein the decontamination process removes oxygen and chemical contamination from the conductive material.

10. The method of claim 8, wherein the decontamination process is performed at least in part in a hydrogen-based gas environment.

11. The method of claim 8, wherein the decontamination process is performed at least in part in a nitrogen-based gas environment.

12. The method of claim 7, wherein the plasma process is performed using nitrogen-containing gases.

13. The method of claim 7, wherein the plasma process is performed using carbon-containing gases.

14. A method comprising:

forming a first recess in a low-k dielectric layer;

forming a first barrier layer on sidewalls and a bottom of the first recess, the first barrier layer comprising a first element;

filling the first recess with a conductive material, the conductive material comprising a second element different from the first element;

performing a decontamination process on the conductive material;

thermal soaking the conductive material in a gas with SiH-bonds to form a second barrier layer on the conductive material and the first barrier layer, wherein the thermal soaking occurs in a non-plasma environment, and wherein the second barrier layer comprises a silicide of the first element and a silicide of the second element; and

performing a passivation process on the second barrier layer.

15. The method of claim 14, wherein the decontamination process is performed in a gas environment comprising H₂, NH₃, or CH₄.

16. The method of claim 14, wherein the decontamination process is performed in a gas environment comprising N₂ or NH₃.

17. The method of claim 14, wherein performing the passivation process comprises performing a plasma process using a NH₃ gas.

18. The method of claim 14, wherein performing the passivation process comprises performing a plasma process using a C_xH_y gas.

19. The method of claim 14, further comprising, prior to the thermal soaking the conductive material, etching the first barrier layer to form a second recess.

20. The method of claim 19, wherein a depth of the second recess is greater than about 5% of a thickness of the conductive material.