Control of electrolyte hydrodynamics for efficient mass transfer during electroplating

Patent metadata

Field	Value
Publication number	US-2016376722-A1
Application number	US-201615261244-A
Country	US
Kind code	A1
Filing date	Sep 9, 2016
Priority date	Jul 2, 2010
Publication date	Dec 29, 2016
Grant date	—

Abstract

Described are apparatus and methods for electroplating one or more metals onto a substrate. Embodiments include electroplating apparatus configured for plating highly uniform metal layers. In specific embodiments, the apparatus includes a flow-shaping element made of an ionically resistive material and having a plurality of channels made through the flow shaping element. The channels allow for transport of the electrolyte through the flow shaping element during electroplating. The channel openings are arranged in a spiral-like pattern on the substrate-facing surface of the flow shaping element such that the center of the spiral-like pattern is offset from the center of the flow shaping element.

First claim

1 . (canceled)

2 . A method of electroplating on a substrate comprising features having a width and/or depth of at least about 2 micrometers, the method comprising:
(a) providing the substrate to a plating chamber, wherein the plating chamber is configured to contain an electrolyte and an anode during electroplating of metal onto the substrate, wherein the plating chamber comprises:
(i) a substrate holder holding the substrate such that a plating face of the substrate is separated from the anode during electroplating, and
(ii) a flow shaping element shaped and configured to be positioned between the substrate and the anode during electroplating, the flow shaping element having a flat surface that is substantially parallel to and separated from the plating face of the substrate by a distance of about 10 millimeters or less during electroplating, wherein the flow shaping element has a plurality of holes; and
(b) electroplating a metal onto the substrate plating surface while rotating the substrate and while flowing the electrolyte such that a transverse flow rate of the electrolyte across the center point of the plating face of the substrate is at least about 3 cm/second, wherein flowing the electrolyte comprises diverting an electrolyte flow exiting the holes of the flow shaping element to a transverse electrolyte flow that is substantially parallel to the plating face of the substrate.

3 . The method of claim 2 , wherein the electroplated metal is selected from the group consisting of copper, tin, a tin-lead composition, a tin-silver composition, nickel, a tin-copper composition, a tin-silver-copper composition, gold, and alloys thereof.

4 . The method of claim 2 , wherein the average flow velocity of the electrolyte exiting the holes of the flow shaping element is at least about 10 cm/second.

5 . The method of claim 2 comprising rotating the substrate at a rate of at least 30 rpm during electroplating.

6 . The method of claim 2 , wherein the holes of the flow shaping element are non-communicating channels.

7 . The method of claim 2 , wherein the electrolyte flows across the plating face of the substrate at a center point of the substrate at a transverse flow rate of about 5 cm/second or greater during electroplating.

8 . The method of claim 2 , wherein the flow shaping element comprises an ionically resistive material selected from the group consisting of polyethylene, polypropylene, polyvinylidene diflouride (PVDF), polytetrafluoroethylene, polysulphone, and polycarbonate.

9 . The method of claim 2 , wherein the flow shaping element is a disk having between about 6,000-12,000 holes.

10 . The method of claim 2 , wherein the flow shaping element has a non-uniform density of holes, with a greater density of holes being present in a region of the flow shaping element that faces a rotational axis of the substrate plating face.

11 . The method of claim 2 , wherein the flow shaping element is between about 5 mm and about 10 mm thick.

12 . The method of claim 2 , further comprising reversing a direction of rotation of the substrate with respect to the flow shaping element during electroplating.

13 . The method of claim 2 , wherein the features on the substrate are wafer level packaging features.

14 . The method of claim 2 , wherein the method comprises electroplating metal in the features at a rate of at least 5 micrometers per minute.

15 . The method of claim 2 , wherein the plating chamber comprises at least one electrolyte flow port, configured to increase transverse flow of electrolyte.

Assignees

• Novellus Systems Inc

Inventors

• Mayer Steven T
• Porter David W

Classifications

• C25D17/02 Primary

  Tanks; Installations therefor · CPC title

• C25D17/001 Primary

  Apparatus specially adapted for electrolytic coating of wafers, e.g. semiconductors or solar cells · CPC title

• C25D17/002 Primary

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

• C25D21/10

  Agitating of electrolytes; Moving of racks · CPC title

• C25D5/08

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