Electro chemical plating process

Patent metadata

Field	Value
Publication number	US-9476135-B2
Application number	US-201313858994-A
Country	US
Kind code	B2
Filing date	Apr 9, 2013
Priority date	Mar 12, 2013
Publication date	Oct 25, 2016
Grant date	Oct 25, 2016

Abstract

The present disclosure relates to an electro-chemical plating (ECP) process which utilizes a dummy electrode as a cathode to perform plating for sustained idle times to mitigate additive dissociation. The dummy electrode also allows for localized plating function to improve product gapfill, and decrease wafer non-uniformity. A wide range of electroplating recipes may be applied with this strategy, comprising current plating up to approximately 200 Amps, localized plating with a resolution of approximately 1 mm, and reverse plating to remove material from the dummy electrode accumulated during the dummy plating process and replenish ionic material within the electroplating solution.

First claim

What is claimed is:

1. A method of electro-chemical plating, comprising:
providing a semiconductor substrate in an electroplating solution comprising a plurality of ions of a material to be deposited;
coupling the semiconductor substrate to an electrode configured to act as a cathode;
applying a first bias between the cathode and an anode which is separated from the electroplating solution by a cationic membrane;
wherein the bias promotes diffusion of the ions of the electroplating solution towards the semiconductor substrate, and wherein the ions reduce to form the material over the semiconductor substrate;
removing the semiconductor substrate from the electroplating solution after the material has been deposited; and
after removing the semiconductor substrate from the electroplating solution and before putting another semiconductor substrate in the electroplating solution, putting the electrode in direct contact with the electroplating solution and applying a second bias between the electrode and the anode over the electroplating solution.

2. The method of claim 1 , wherein the electrode is configured to apply a local bias to the substrate, and wherein the local bias attracts a majority of the ions to regions of the substrate to which the local bias is applied, resulting in a non-uniform deposition thickness of the material over the substrate.

3. The method of claim 2 , wherein the electrode comprises localized wiring distributed within a backside substrate, wherein the localized wiring is configured to deliver a current to a front surface of the backside substrate, and wherein the current generates the local bias to the substrate.

4. The method of claim 3 , wherein the localized wiring is distributed with a spacing of between approximately 1 millimeter (mm) and approximately 300 mm.

5. The method of claim 4 , wherein the localized wiring comprises a pattern including concentric rings of continuous wiring.

6. The method of claim 3 , wherein the current is between approximately 0 Amps and approximately 200 Amps.

7. The method of claim 1 , wherein the electroplating solution comprises ionized cuprous species or an ionized cupric species configured to act as a seed layer or a growth layer over the substrate.

8. The method of claim 7 , wherein the electroplating solution further comprises:
thiourea, benzotriazole, or Janus Green B configured as a leveler;
bis(sodiumsulfopropyl) disulfide configured as an accelerator; or
polyethylene glycol or polypropylene glycol configured as a suppressor.

9. The method of claim 1 , wherein the first bias comprises a voltage between approximately 0 Volts and approximately 10 Volts.

10. A method of electro-chemical plating, comprising:
providing a semiconductor substrate in an electroplating solution comprising:
a plurality of ions of material to be deposited; and
additives configured to react with the material to regulate a presence of the plurality of ions;

coupling the semiconductor substrate to an electrode;
providing a voltage between an anode residing within the electroplating solution and the electrode, such that the semiconductor substrate acts a cathode, whereupon the material is deposited over a front surface of the semiconductor substrate;
decoupling the semiconductor substrate from the electrode and removing the semiconductor substrate from the electroplating solution; and
after removing the semiconductor substrate from the electroplating solution and before putting another semiconductor substrate in the electroplating solution, putting the electrode in direct contact with the electroplating solution and applying a bias between the electrode and the anode.

11. The method of claim 10 , wherein a reverse bias is periodically applied to the electrode with a periodicity.

12. The method of claim 11 , wherein the periodicity comprises approximately 30 minutes.

13. The method of claim 10 , wherein the electrode is disposed over a backside substrate and configured receive a current from a current source through the backside substrate, and wherein the current is between approximately 0 Amps and approximately 200 Amps and generates a bias on the electrode.

14. The method of claim 10 , wherein the electroplating solution comprises ionized cuprous species or an ionized cupric species configured to act as a seed layer or a growth layer over the substrate.

15. The method of claim 14 , wherein the electroplating solution further comprises:
thiourea, benzotriazole, or Janus Green B configured as a leveler;
bis(sodiumsulfopropyl) disulfide configured as an accelerator; or
polyethylene glycol or polypropylene glycol configured as a suppressor.

16. A method of electro-chemical plating (ECP), comprising:
providing an ECP system configured to perform an electroplating process on a substrate, the ECP system comprising an electroplating solution arranged between a first electrode and a second electrode;
coupling the substrate to the first electrode and positioning the substrate in direct contact with the electroplating solution and applying a first voltage between the first and second electrodes while the substrate is in direct contact with the electroplating solution, wherein applying the first voltage reduces ions of the electroplating solution into a first deposit on the substrate;
removing the substrate from the electroplating solution after the first voltage has been applied; and
after removing the substrate from the electroplating solution and before putting another substrate in the electroplating solution, putting the first electrode in direct contact with the electroplating solution and applying a second voltage between the first and second electrodes, wherein applying the second voltage reduces ions of the electroplating solution into a second deposit on the first electrode.

17. The method of claim 16 , further comprising: applying a third voltage between the first and second electrodes to remove the second deposit from the first electrode.

18. The method of claim 17 , wherein applying the first voltage between the first and second electrodes comprises: applying a first initial voltage between the first and second electrodes to fill first openings in the substrate with the first deposit; and applying a second initial voltage between the first and second electrodes to fill second openings in the substrate with the first deposit, wherein the second openings have a larger width than the first openings, and wherein the second initial voltage is larger than the first initial voltage.

19. The method of claim 16 , wherein the electroplating solution comprises ionized cuprous species or an ionized cupric species.

Assignees

• Taiwan Semiconductor Mfg Co Ltd
• Taiwan Semiconductor Mfg Co Ltd

Inventors

• Chang Chih-Yi
• Yang Liang-Yueh Ou
• Kao Chen-Yuan
• Su Hung-Wen

Classifications

• H10P14/47

  Electrolytic deposition, i.e. electroplating; Electroless plating · CPC title

• H10W20/056

  by filling conductive material into holes, grooves or trenches · CPC title

• C25D5/02 Primary

  Electroplating of selected surface areas · CPC title

• C25D7/123

  Semiconductors first coated with a seed layer or a conductive layer · CPC title

• C25D17/002

  Cell separation, e.g. membranes, diaphragms · CPC title