Electroplating apparatus for tailored uniformity profile

Patent metadata

Field	Value
Publication number	US-10920335-B2
Application number	US-201816007800-A
Country	US
Kind code	B2
Filing date	Jun 13, 2018
Priority date	Nov 7, 2008
Publication date	Feb 16, 2021
Grant date	Feb 16, 2021

Abstract

Methods of electroplating metal on a substrate while controlling azimuthal uniformity, include, in one aspect, providing the substrate to the electroplating apparatus configured for rotating the substrate during electroplating, and electroplating the metal on the substrate while rotating the substrate relative to a shield such that a selected portion of the substrate at a selected azimuthal position dwells in a shielded area for a different amount of time than a second portion of the substrate having the same average arc length and the same average radial position and residing at a different angular (azimuthal) position. The shield is positioned in close proximity of the substrate (e.g., within a distance that is equal to 0.1 of the substrate's radius). The shield in some embodiments may be an ionically resistive ionically permeable element having an azimuthally asymmetric distribution of channels.

First claim

The invention claimed is:

1. A method of electroplating a metal on a substrate while controlling azimuthal uniformity, the method comprising:
(a) providing the substrate into an electroplating apparatus configured for rotating the substrate during electroplating, wherein the electroplating apparatus comprises a shield, configured for providing azimuthally asymmetric shielding, wherein the shield is positioned during electroplating such that a distance between the shield and a working surface of the substrate is no more than about 0.1 of the radius of the substrate; and
(b) electroplating the metal on the substrate while rotating the substrate relative to the shield such that a selected portion of the substrate at a selected azimuthal position dwells in a shielded area for a different amount of time than a second portion of the substrate having the same average arc length and the same average radial position and residing at a different angular azimuthal position.

2. The method of claim 1 , wherein the shield is positioned during electroplating such that a distance between the shield and a working surface of the substrate is no more than about 4 mm.

3. The method of claim 2 , wherein the shield is an annular shield having an irregular portion.

4. The method of claim 1 , wherein (b) comprises rotating the substrate at a variable speed.

5. The method of claim 1 , wherein (b) comprises rotating the substrate at a first speed when the selected portion of the substrate is less shielded and at a second speed when the selected portion of the substrate is more shielded, wherein one full rotation of the substrate comprises a first period of rotation at the first speed and a second period of rotation at the second speed.

6. The method of claim 5 , wherein the second speed is lower than the first speed.

7. The method of claim 5 , wherein the first speed is at least about 20 rpm and the second speed is less than about 10 rpm.

8. The method of claim 5 , wherein the substrate makes at least five full rotations with variable speed during the course of electroplating.

9. The method of claim 1 , wherein (b) comprises rotating the substrate bidirectionally, such that the selected portion of the substrate dwells in the shielded area for a different amount of time than a second portion of the substrate having the same average arc length and the same average radial position and residing at a different angular azimuthal position.

10. The method of claim 1 , wherein the electroplating apparatus further comprises an ionically resistive ionically permeable element positioned such that it is separated from a working surface of the substrate by a distance of about 10 mm or less during electroplating.

11. The method of claim 10 , wherein the ionically resistive ionically permeable element comprises a plurality of non-communicating channels, wherein the shield eclipses a portion of the non-communicating channels.

12. The method of claim 1 , wherein the shield is an ionically resistive ionically permeable element having a plurality of channels, wherein the element has an azimuthally asymmetric distribution of channels.

13. The method of claim 1 , further comprising registering a selected azimuthal position on the substrate prior to electroplating.

14. The method of claim 1 , wherein the shield is an annular shield having a portion departing from annularity.

15. A method of electroplating a metal on a substrate while controlling azimuthal uniformity, the method comprising:
(a) providing the substrate into an electroplating apparatus configured for rotating the substrate during electroplating, wherein the electroplating apparatus comprises a shield, configured for providing azimuthally asymmetric shielding, wherein the shield is an ionically resistive ionically permeable element having an azimuthally asymmetric distribution of channels; and
(b) electroplating the metal on the substrate while rotating the substrate relative to the shield such that a selected portion of the substrate at a selected azimuthal position dwells in a shielded area for a different amount of time than a second portion of the substrate having the same average arc length and the same average radial position and residing at a different angular azimuthal position.

16. The method of claim 15 , wherein (b) comprises rotating the substrate at a first speed when the selected portion of the substrate is less shielded and at a second speed when the selected portion of the substrate is more shielded, wherein one full rotation of the substrate comprises a first period of rotation at the first speed and a second period of rotation at the second speed.

17. The method of claim 15 , wherein the second speed is lower than the first speed.

18. The method of claim 15 , wherein (b) comprises rotating the substrate bidirectionally, such that the selected portion of the substrate dwells in the shielded area for a different amount of time than a second portion of the substrate having the same average arc length and the same average radial position and residing at a different angular azimuthal position.

19. The method of claim 15 , further comprising registering a selected azimuthal position of the substrate before electroplating.

Assignees

• Novellus Systems Inc

Inventors

• Mayer Steven T
• Porter David W
• Buckalew Bryan L
• Rash Robert

Classifications

• H10P14/47

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

• H10W20/043

  for electroplating · CPC title

• C25D17/12

  Shape or form (C25D17/14 takes precedence) · CPC title

• C25D5/04

  Electroplating with moving electrodes · CPC title

• C25D17/002

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