Dynamic modulation of cross flow manifold during elecroplating

Patent metadata

Field	Value
Publication number	US-10364505-B2
Application number	US-201615225716-A
Country	US
Kind code	B2
Filing date	Aug 1, 2016
Priority date	May 24, 2016
Publication date	Jul 30, 2019
Grant date	Jul 30, 2019

Abstract

The embodiments herein relate to methods and apparatus for electroplating one or more materials onto a substrate. Typically, the embodiments herein utilize a channeled plate positioned near the substrate, creating a cross flow manifold between the channeled plate and substrate, and on the sides by a flow confinement ring. A seal may be provided between the bottom surface of a substrate holder and the top surface of an element below the substrate holder (e.g., the flow confinement ring). During plating, fluid enters the cross flow manifold through channels in the channeled plate, and through a cross flow inlet, then exits at the cross flow exit, positioned opposite the cross flow inlet. The apparatus may switch between a sealed state and an unsealed state during electroplating, for example by lowering and lifting the substrate and substrate holder as appropriate to engage and disengage the seal.

First claim

What is claimed is:

1. An electroplating apparatus comprising:
(a) an electroplating chamber configured to contain an electrolyte and an anode while electroplating metal onto a substantially planar substrate;
(b) a substrate holder configured to hold the substantially planar substrate such that a plating face of the substrate is separated from the anode during electroplating, the substrate holder comprising a cup that supports the substrate at its periphery;
(c) an ionically resistive element including a substrate-facing surface that is separated from the plating face of the substrate by a gap of about 10 mm or less, the gap forming a cross flow manifold between the ionically resistive element and the substrate,
wherein the ionically resistive element is at least coextensive with the plating face of the substrate during electroplating, and wherein the ionically resistive element is adapted to provide ionic transport through the ionically resistive element during electroplating;

(d) a side inlet to the cross flow manifold for introducing electrolyte to the cross flow manifold;
(e) a side outlet to the cross flow manifold for receiving electrolyte flowing in the cross flow manifold,
wherein the side inlet and side outlet are positioned proximate azimuthally opposing perimeter locations on the plating face of the substrate during electroplating, and wherein the side inlet and side outlet are adapted to generate cross flowing electrolyte in the cross flow manifold; and

(f) a sealing member for wholly or partially sealing one or more outlets to the cross flow manifold other than the side outlet, wherein the sealing member is positioned at least partially below the cup of the substrate holder, and wherein when the sealing member is engaged the apparatus is in a sealed state, and when the sealing member is not engaged the apparatus is in an unsealed state; and
(g) a controller configured to cause intermittently switching between the sealed state and the unsealed state during electroplating.

2. The apparatus of claim 1 , further comprising a flow confinement element positioned peripherally in the cross flow manifold between the ionically resistive element and the substrate holder.

3. The apparatus of claim 2 , further comprising a leakage gap between a surface of the substrate holder and a surface of the flow confinement element, wherein the sealing member is configured to seal the leakage gap when the substrate holder is sufficiently near the flow confinement element.

4. The apparatus of claim 3 , wherein the sealing member seals at least about 75% of the leakage gap.

5. The apparatus of claim 4 , wherein the sealing member seals about 100% of the leakage gap.

6. The apparatus of claim 2 , wherein the side outlet is formed in the flow confinement element.

7. The apparatus of claim 6 , wherein the side outlet comprises a vent region in the flow confinement element, the vent region spanning between about 20-120 degrees proximate the periphery of the substrate.

8. The apparatus of claim 2 , wherein the sealing member is fixedly or releasably attached to the flow confinement element.

9. The apparatus of claim 2 , wherein the sealing member is fixedly or releasably attached to a scaffold that is different from the substrate holder and the flow confinement element.

10. The apparatus of claim 1 , wherein the sealing member comprises a compressible material.

11. The apparatus of claim 10 , wherein the sealing member comprises a fluoropolymer elastomer.

12. The apparatus of claim 11 , wherein the fluoropolymer elastomer comprises between about 65-70% fluorine.

13. The apparatus of claim 1 , wherein the sealing member is fixedly or releasably attached to the substrate holder.

14. The apparatus of claim 1 , wherein the controller is configured to cause rotating the substrate while the apparatus is in the unsealed state.

15. The apparatus of claim 14 , wherein the controller is configured to cause not rotating the substrate while the apparatus is in the sealed state.

16. A method for electroplating on a substrate, the method comprising:
(a) receiving a substantially planar substrate in a substrate holder of an electroplating apparatus, where the substrate holder comprises a cup configured to support the substrate at its periphery such that the plating face of the substrate is exposed and is separated from an anode during electroplating,
(b) immersing the substrate in electrolyte, where a gap of about 10 mm or less is formed between the plating face of the substrate and an upper surface of an ionically resistive element, the gap forming a cross flow manifold, wherein the ionically resistive element is at least coextensive with the plating face of the substrate, and wherein the ionically resistive element is adapted to provide ionic transport through the ionically resistive element during electroplating,
(c) flowing electrolyte in contact with the substrate in the substrate holder
(i) from a side inlet, into the cross flow manifold, and out a side outlet, and, optionally, (ii) from below the ionically resistive element, through the ionically resistive element, into the cross flow manifold, and out the side outlet, wherein the side inlet and side outlet are positioned proximate azimuthally opposed perimeter locations on the plating face of the substrate, wherein the side inlet and side outlet are designed or configured to generate cross flowing electrolyte in the cross flow manifold during electroplating, and wherein a sealing member wholly or partially seals one or more outlets to the cross flow manifold other than the side outlet during at least a portion of electroplating, wherein when the sealing member is engaged the electroplating apparatus is in a sealed state, and when the sealing member is not engaged the electroplating apparatus is in an unsealed state, wherein the sealing member is positioned at least partially below the cup of the substrate holder; and

(d) intermittently switching the electroplating apparatus between the sealed state and the unsealed state while electroplating material onto the plating face of the substrate while flowing the electrolyte as in (c).

17. The method of claim 16 , wherein electroplating material in (d) comprises
(i) electroplating material while rotating the substrate when the electroplating apparatus is in the unsealed state,
(ii) electroplating material while engaging the sealing member to seal the cross flow manifold of the electroplating apparatus,
(iii) electroplating material while maintaining the substrate rotationally stationary when the electroplating apparatus is in the sealed state, and
(iv) electroplating material while disengaging the sealing member to unseal the cross flow manifold of the electroplating apparatus.

18. The method of claim 17 , wherein operations (i)-(iv) of electroplating material in (d) are performed at least three times during electroplating on the substrate.

19. The method of claim 17 , wherein the electroplating apparatus is in the sealed state for more than half of a total plating time.

20. The method of claim 16 , wherein electroplating material in (d) comprises
(i) applying a first current to the substrate while maintaining the substrate rotationally stationary when the electroplating apparatus is in the sealed state, and
(ii) either (A) applying no current to the substrate, or (B) applying a current that is different from the first current while rotating the substrate when the electroplating apparatus is in the unsealed state.

Assignees

• Lam Res Corp

Inventors

• Thorkelsson Kari
• Berke Aaron
• Buckalew Bryan L
• Mayer Steven T

Classifications

• C25D17/008

  Current shielding devices · CPC title

• C25D17/06

  Suspending or supporting devices for articles to be coated · CPC title

• C25D21/10

  Agitating of electrolytes; Moving of racks · CPC title

• C25D5/08 Primary

  Electroplating with moving electrolyte e.g. jet electroplating {(using locally applied jets of electrolyte C25D5/026)} · CPC title

• C25D5/18

  Electroplating using modulated, pulsed or reversing current · CPC title