Chemical mechanical polish slurry and method of manufacture

Patent metadata

Field	Value
Publication number	US-11043396-B2
Application number	US-201816179307-A
Country	US
Kind code	B2
Filing date	Nov 2, 2018
Priority date	Jul 31, 2018
Publication date	Jun 22, 2021
Grant date	Jun 22, 2021

Abstract

Methods of manufacturing a chemical-mechanical polishing (CMP) slurry and methods of performing CMP process on a substrate comprising metal features are described herein. The CMP slurry may be manufactured using a balanced concentration ratio of chelator additives to inhibitor additives, the ratio being determined based on an electro potential (Ev) value of a metal material of the substrate. The CMP process may be performed on the substrate based on the balanced concentration ratio of chelator additives to inhibitor additives of the CMP slurry.

First claim

What is claimed is:

1. A method, comprising:
measuring an electrical potential of a conductive material of a workpiece, the conductive material comprising an alloy;
selecting a composition of a slurry to apply to a surface of the workpiece, wherein the composition of the slurry has a ratio of a first volume of a first additive to a second volume of a second additive, the selecting the composition comprising:
the ratio being based on the electrical potential of the conductive material, the ratio being between 40% and 100%, 40% inclusive and 100% inclusive, when the electrical potential of the conductive material of the workpiece is less than or equal to a threshold voltage; and
the ratio being between 100% and 140%, 140% inclusive, when the electrical potential of the conductive material of the workpiece is greater than the threshold voltage;
applying the slurry to the surface of the workpiece; and
performing a chemical mechanical polishing procedure to the surface of the workpiece using the slurry.

2. The method of claim 1 , wherein the slurry further comprises a reactant additive, the reactant additive being an oxidizing agent of the conductive material of the workpiece.

3. The method of claim 1 , wherein the first additive is a chelator agent.

4. The method of claim 3 , the chelator agent being an amino group selected from the group consisting of primary amino groups, secondary amino groups, and ternary amino groups.

5. The method of claim 3 , wherein the second additive is an inhibitor agent.

6. The method of claim 5 , wherein the inhibitor agent is one of a carboxyl type inhibitor and a benzene type inhibitor.

7. The method of claim 5 , the method further comprising:
preparing the slurry using the first volume of the chelator agent and using the second volume of the inhibitor agent.

8. A method comprising:
measuring an electrical potential of a material of a conductor, the conductor comprising an alloy;
selecting between a first ratio and a second ratio of a slurry, each of the first ratio and the second ratio being defined by a ratio of a first volume of a chelator additive to a second volume of an inhibitor additive, the second ratio being greater than the first ratio, the selecting between the first ratio and the second ratio comprising choosing between the first ratio and the second ratio depending on whether the electrical potential of the material is less than or equal to a threshold potential or greater than the threshold potential, respectively;
dispensing the slurry onto a surface of a substrate, the substrate including the conductor and the slurry comprising the first volume of the chelator additive and the second volume of the inhibitor additive; and
using the slurry to perform a chemical mechanical polishing on the surface of the substrate.

9. The method of claim 8 further comprising:
determining a material property of the conductor; and
determining a first type of the inhibitor additive based on the material property of the conductor, the inhibitor additive being one of a carboxyl type inhibitor additive and a benzene type inhibitor additive.

10. The method of claim 9 further comprising:
determining a second type of the chelator additive based on the material property of the conductor and based on the first type of the inhibitor additive, the second type of the chelator additive being an amino group selected from the group consisting of primary amino groups, secondary amino groups, and ternary amino groups.

11. The method of claim 8 , further comprising:
mixing the first volume of the chelator additive and the second volume of the inhibitor additive into a base slurry to form the slurry.

12. The method of claim 11 , further comprising:
mixing a third volume of an oxidizing agent into the base slurry.

13. The method of claim 12 , wherein the oxidizing agent oxidizes the material of the conductor.

14. The method of claim 12 , wherein:
0%≤the chelator to inhibitor ratio ≤60%, when the electrical potential of the material of the conductor is less than or equal to the threshold potential; and
60%<the chelator to inhibitor ratio 100%, when the electrical potential of the material of the conductor is greater than the threshold potential.

15. A method comprising:
choosing a chelator to inhibitor ratio of a slurry based on an electrical potential of a material of a conductor disposed within a substrate, the conductor comprising an alloy;
removing the slurry from a holding tank, the slurry comprising a first volume of a chelator additive and a second volume of an inhibitor additive, the first volume and the second volume being defined by the chelator to inhibitor ratio; and
sending the slurry to a chemical mechanical polishing (CMP) unit configured to perform a chemical mechanical polishing procedure on a surface of the substrate using the slurry.

16. The method of claim 15 , wherein the slurry further comprises a third volume of an oxidizing agent.

17. The method of claim 15 , wherein the material of the conductor comprises copper (Cu).

18. The method of claim 15 , wherein the material of the conductor comprises cobalt (Co).

19. The method of claim 15 , wherein the chelator to inhibitor ratio is determined according to: 40%≤the chelator to inhibitor ratio ≤100%, when the electrical potential of the material of the conductor is ≤−0.25V; and 100%<the chelator to inhibitor ratio ≤140%, when the electrical potential of the material of the conductor is >−0.25V.

20. The method of claim 15 , wherein the chelator to inhibitor ratio is determined according to: 0%≤the chelator to inhibitor ratio ≤60%, when the electrical potential of the material of the conductor is ≤−0.25V; and 60%<the chelator to inhibitor ratio ≤100%, when the electrical potential of the material of the conductor is >−0.25V.

Assignees

• Taiwan Semiconductor Mfg Co Ltd

Inventors

• Kung Chun-Hao
• Chen Tung-Kai
• Chang Chih-Chieh
• Liao Kao-Feng
• Huang Hui-Chi
• Chen Kei-Wei

Classifications

• H10P52/402

  of semiconductor materials · CPC title

• H10W20/033

  in openings in dielectrics · CPC title

• H10P52/403 Primary

  of conductive or resistive materials · CPC title

• C09G1/02

  containing abrasives or grinding agents {(abrasives as such C09K3/14; polishing of semi-conductors H10P52/40)} · CPC title

• C09G1/04

  Aqueous dispersions (C09G1/02 takes precedence) · CPC title