Method of enabling seamless cobalt gap-fill

• US 9,330,939 B2
• Filed: 03/06/2013
• Issued: 05/03/2016
• Est. Priority Date: 03/28/2012
• Status: Active Grant

• Current Assignee: Applied Materials Incorporated
• Original Assignee: Applied Materials Incorporated
• Inventors: Zope, Bhushan N., Gelatos, Avgerinos V., Zheng, Bo, Lei, Yu, Fu, Xinyu, Gandikota, Srinivas, Yu, Sang-Ho, Abraham, Mathew
• Primary Examiner(s): Cao, Phat X
• Assistant Examiner(s): Hoque, Mohammad M
• Application Number:
  US13/786,644
• Publication Number:
  US 20130260555A1
• Time in Patent Office: 1,154 Days
• Field of Search: 438/660
• US Class Current: 1/1
• CPC Class Codes: H01L 21/02057 Cleaning during device manufacture
• 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 21/28556 by chemical means, e.g. CVD, LPCVD, PECVD, laser CVD H01L21/28518 - H01L21/28537 and H01L21/28568 take precedence
• CPC Class Codes: H01L 21/4846 Leads on or in insulating or insulated substrates, e.g. metallisation H01L21/4821 takes precedence; metallisation of ceramics in general C04B41/51; printed circuits H05K3/00
• 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 21/76846 Layer combinations
• CPC Class Codes: H01L 21/76856 by treatment in plasmas or gaseous environments, e.g. nitriding a refractory metal liner
• CPC Class Codes: H01L 21/76877 Filling of holes, grooves or trenches, e.g. vias, with conductive material
• CPC Class Codes: H01L 21/76879 by selective deposition of conductive material in the vias, e.g. selective C.V.D. on semiconductor material, plating plating on semiconductors in general H01L21/288
• CPC Class Codes: H01L 21/76883 Post-treatment or after-treatment of the conductive material
• CPC Class Codes: H01L 23/53209 based on metals, e.g. alloys, metal silicides H01L23/53285 takes precedence
• CPC Class Codes: H01L 23/5329 Insulating materials
• CPC Class Codes: H01L 29/66621 using etching to form a recess at the gate location etching of semiconductor bodies H01L21/302

Abstract

Methods for depositing a contact metal layer in contact structures of a semiconductor device are provided. In one embodiment, a method for depositing a contact metal layer for forming a contact structure in a semiconductor device is provided. The method comprises performing a cyclic metal deposition process to deposit a contact metal layer on a substrate and annealing the contact metal layer disposed on the substrate. The cyclic metal deposition process comprises exposing the substrate to a deposition precursor gas mixture to deposit a portion of the contact metal layer on the substrate, exposing the portion of the contact metal layer to a plasma treatment process, and repeating the exposing the substrate to a deposition precursor gas mixture and exposing the portion of the contact metal layer to a plasma treatment process until a predetermined thickness of the contact metal layer is achieved.

Claims

1. A method for depositing a contact structure in a semiconductor device, comprising:

performing a cyclic metal deposition process to deposit at least part of a gate electrode in openings formed on a silicon containing substrate, the at least part of a gate electrode comprising a cobalt contact metal adjacent a metal containing layer, the cyclic metal deposition process comprising;

exposing the substrate to a deposition precursor gas mixture to deposit a portion of the cobalt contact metal on the substrate;

exposing the portion of the cobalt contact metal to a plasma treatment process; and

repeating the exposing the substrate to a deposition precursor gas mixture and the exposing the portion of the cobalt contact metal to a plasma treatment process until a predetermined thickness of the cobalt contact metal is achieved; and

annealing the cobalt contact metal disposed on the substrate.

2. The method of claim 1, wherein the deposition precursor gas mixture includes a cobalt containing precursor and a reducing gas.

3. The method of claim 2, wherein the cobalt containing precursor is dicobalt hexacarbonyl butylacetylene (CCTBA) and the reducing gas is hydrogen (H₂).

4. The method of claim 1, further comprising:

supplying a pretreatment gas comprising NH₃ to pretreat the substrate prior to the performing a cyclic metal deposition process.

5. The method of claim 1, wherein annealing the cobalt contact metal disposed on the substrate further comprises:

supplying a gas mixture including at least one of an inert gas and hydrogen gas (H₂) while providing the heat energy to the cobalt contact metal.

6. The method of claim 1, further comprising:

repeating the performing a cyclic metal deposition process and the annealing the cobalt contact metal disposed on the substrate until a predetermined thickness of the cobalt contact metal is achieved.

7. The method of claim 1, wherein the exposing the substrate to a deposition precursor gas mixture to deposit a portion of the cobalt contact metal on the substrate and the exposing the portion of the cobalt contact metal to a plasma treatment process are performed simultaneously.

8. The method of claim 1, wherein the exposing the portion of the cobalt contact metal to a plasma treatment process comprises supplying a gas selected from hydrogen (H₂), nitrogen (N₂), ammonia (NH₃), and combinations thereof to reduce roughness of the portion of the cobalt contact metal.

16. The method of claim 1, wherein the cobalt contact metal formed by the cyclic metal deposition process is substantially free of seams.

9. A method for depositing a contact structure in a semiconductor device, comprising:

performing a barrier layer deposition process to deposit a barrier layer on a substrate;

performing a wetting layer deposition to deposit a metal-containing wetting layer on the substrate;

performing a cyclic metal deposition process to deposit at least part of a gate electrode in openings formed on a silicon containing substrate, the at least part of a gate electrode comprising a cobalt contact metal adjacent the metal-containing wetting layer, comprising;

exposing the substrate to a deposition precursor gas mixture to deposit a portion of the cobalt contact metal on the substrate;

exposing the portion of the cobalt contact metal to a plasma treatment process; and

repeating the exposing the substrate to a deposition precursor gas mixture and exposing the portion of the cobalt contact metal to a plasma treatment process until a predetermined thickness of the cobalt contact metal is achieved; and

annealing the cobalt contact metal disposed on the substrate.

10. The method of claim 9, wherein the deposition precursor gas mixture includes a cobalt containing precursor and a reducing gas.

11. The method of claim 10, wherein the cobalt containing precursor is dicobalt hexacarbonyl butylacetylene (CCTBA) and the reducing gas is hydrogen (H₂).

12. The method of claim 9, further comprising:

supplying a pretreatment gas comprising NH₃ to pretreat the substrate prior to the performing a cyclic metal deposition process.

13. The method of claim 9, wherein annealing the cobalt contact metal disposed on the substrate further comprises:

supplying a gas mixture including at least one of an inert gas and hydrogen gas (H₂) while providing the heat energy to the cobalt contact metal.

14. The method of claim 9, further comprising:

repeating the performing a cyclic metal deposition process and the annealing the cobalt contact metal disposed on the substrate until a predetermined thickness of the cobalt contact metal is achieved.

15. The method of claim 9, wherein the wetting layer is deposited by a process selected from PVD Co, CVD TiN, PVD TiN, CVD Ru, PVD Ru, nitridation of PVD Ti, or combinations thereof to prevent inter-diffusion of the substrate and the cobalt contact metal and to increase the adhesion of the cobalt contact metal to the substrate.

17. The method of claim 9, wherein the cobalt contact metal formed by the cyclic metal deposition process is substantially free of seams.

18. The method of claim 9, wherein the barrier layer is a titanium material or a titanium nitride material.