Magnetic structure for metal plating control

• US 10,526,719 B2
• Filed: 08/21/2013
• Issued: 01/07/2020
• Est. Priority Date: 08/21/2013
• Status: Active Grant

• Current Assignee: Taiwan Semiconductor Manufacturing Company Limited
• Original Assignee: Taiwan Semiconductor Manufacturing Company Limited
• Inventors: Tsai, Ming-Chin, Kao, Chung-En, Lu, Victor Y.
• Primary Examiner(s): Cohen, Brian W
• Assistant Examiner(s): Chung, Ho-Sung
• Application Number:
  US13/971,881
• Publication Number:
  US 20150053563A1
• Time in Patent Office: 2,330 Days
• CPC Class Codes: C25D 17/001 Apparatus specially adapted for electrolytic coating of wafers, e.g. semiconductors or solar cells
• CPC Class Codes: C25D 17/007 Current directing devices
• CPC Class Codes: C25D 5/007 Electroplating using magnetic fields, e.g. magnets
• CPC Class Codes: C25D 7/123 Semiconductors first coated with a seed layer or a conductive layer

Abstract

Among other things, one or more systems and techniques for promoting metal plating profile uniformity are provided. A magnetic structure is positioned relative to a semiconductor wafer that is to be electroplated with metal during a metal plating process. In an embodiment, the magnetic structure applies a force that decreases an edge plating current by moving metal ions away from a wafer edge of the semiconductor wafer. In an embodiment, the magnetic structure applies a force that increases a center plating current by moving metal ions towards a center portion of the semiconductor wafer. In this way, the edge plating current has a current value that is similar to a current value of the center plating current. The similarity between the center plating current and the edge plating current promotes metal plating uniformity.

Claims

1. A system for promoting metal plating profile uniformity, comprising:

a plating cell configured to contain a semiconductor wafer, wherein, when the semiconductor wafer is disposed within the plating cell, a bottom surface of the semiconductor wafer faces an anode;

a circular-shaped magnetic structure configured to modify at least one of an edge plating current or a center plating current associated with a metal plating process for the semiconductor wafer; and

a magnet movement component configured to modify a position of the circular-shaped magnetic structure from a first position to a second position with respect to the semiconductor wafer by moving the circular-shaped magnetic structure in a first direction and rotating the circular-shaped magnetic structure about an axis parallel to a diameter of the circular-shaped magnetic structure, wherein the circular-shaped magnetic structure is entirely disposed between a center of the semiconductor wafer and an edge of the semiconductor wafer when the circular-shaped magnetic structure is positioned at the second position.

2. The system of claim 1, the circular-shaped magnetic structure configured to:

provide a magnetic force to decrease the edge plating current.

3. The system of claim 1, the circular-shaped magnetic structure configured to:

provide a magnetic force to increase the center plating current.

4. The system of claim 1, the circular-shaped magnetic structure configured to:

apply a force to a metal ion to move the metal ion towards a center portion of the semiconductor wafer.

5. The system of claim 1, the circular-shaped magnetic structure configured to:

apply a force to a metal ion to move the metal ion away from a wafer edge of the semiconductor wafer.

6. The system of claim 1, the circular-shaped magnetic structure located externally to the plating cell.

7. The system of claim 6, the circular-shaped magnetic structure configured to:

apply a force to a metal ion to move the metal ion away from a wafer edge of the semiconductor wafer proximate a housing of the plating cell.

8. The system of claim 1, the circular-shaped magnetic structure located inside the plating cell.

9. The system of claim 1, the circular-shaped magnetic structure located relative to the semiconductor wafer such that the semiconductor wafer is situated between the circular-shaped magnetic structure and the anode.

10. The system of claim 9, the circular-shaped magnetic structure configured to:

apply a force to a metal ion generated by the anode to move the metal ion towards a center portion of the semiconductor wafer.

11. The system of claim 1, the magnet movement component configured to:

modify a rotational speed of the circular-shaped magnetic structure.

12. The system of claim 1, a difference between the first position and the second position corresponding to a change in a horizontal distance between the circular-shaped magnetic structure and the center of the semiconductor wafer.

13. The system of claim 1, comprising:

a magnet strength component configured to;

modify a strength of a magnetic field generated by the circular-shaped magnetic structure.

14. The system of claim 1, wherein the diameter of the circular-shaped magnetic structure is less than a diameter of the semiconductor wafer.

15. The system of claim 1, wherein the circular-shaped magnetic structure defines a ring.

16. A system for promoting metal plating profile uniformity, comprising:

a plating cell configured to perform a metal plating process upon a semiconductor wafer, wherein when the semiconductor wafer is disposed within the plating cell, a bottom surface of the semiconductor wafer faces an anode; and

a ring-shaped magnetic structure having a diameter that is less than a diameter of the semiconductor wafer, wherein

the ring-shaped magnetic structure is configured to apply a force to at least one of;

decrease an edge plating current associated with the metal plating process, or

increase a center plating current associated with the metal plating process; and

a magnet movement component configured to modify a position of the ring-shaped magnetic structure from a first position to a second position with respect to the semiconductor wafer by moving the ring-shaped magnetic structure in a first direction and rotating the ring-shaped magnetic structure about an axis parallel to the diameter of the ring-shaped magnetic structure, wherein the ring-shaped magnetic structure is entirely disposed between a center of the semiconductor wafer and an edge of the semiconductor wafer when the ring-shaped magnetic structure is positioned at the second position.

17. A system for promoting metal plating profile uniformity, comprising:

a metal plating cell configured to contain a semiconductor wafer having a first surface to be plated;

a circular-shaped magnetic structure configured to generate a magnetic field that interacts with metal ions within the metal plating cell; and

a magnet movement component configured to move the circular-shaped magnetic structure between a first position at which the circular-shaped magnetic structure is substantially centered over the semiconductor wafer to a second position at which the circular-shaped magnetic structure is entirely disposed between a center of the semiconductor wafer and an edge of the semiconductor wafer and to rotate the circular-shaped magnetic structure about an axis parallel to a diameter of the circular-shaped magnetic structure.

18. The system of claim 17, the magnetic movement component configured to move the circular-shaped magnetic structure in a direction perpendicular to the first surface of the semiconductor wafer.

19. The system of claim 17, wherein the circular-shaped magnetic structure configured is to provide a magnetic force to increase a center plating current to direct the metal ions toward the center of the semiconductor wafer.

20. The system of claim 17, wherein the semiconductor wafer is disposed between an anode and the circular-shaped magnetic structure.