Control of electrolyte flow dynamics for uniform electroplating

Patent metadata

Field	Value
Publication number	US-2016273119-A1
Application number	US-201514662823-A
Country	US
Kind code	A1
Filing date	Mar 19, 2015
Priority date	Mar 19, 2015
Publication date	Sep 22, 2016
Grant date	—

Abstract

The uniformity of electroplating a metal (e.g., copper) on a semiconductor wafer is improved by using an electroplating apparatus having a flow-shaping element positioned in the proximity of the semiconductor wafer, wherein the flow-shaping element is made of a resistive material and has two types of non-communicating channels made through the resistive material, such that the electrolyte is transported towards the substrate through both types of channels. The first type of channels is not perpendicular to the plane defined by a plating face of the substrate. The second type of channels is perpendicular to the plane defined by the plating face of the substrate. The channels of the first and second type are substantially spatially segregated. In one embodiment a plurality of channels of the first type are located in the central portion of the flow-shaping element and are surrounded by a plurality of channels of the second type.

First claim

What is claimed is:

1 . An electroplating apparatus comprising:
(a) a plating 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; (c) a flow-shaping element comprising a substrate-facing surface and an opposing surface, the flow-shaping element comprising an ionically resistive material with a plurality of non-communicating channels made through the flow-shaping element, wherein said non-communicating channels allow for transport of the electrolyte through the flow-shaping element during electroplating from the opposing surface to the substrate-facing surface of the flow-shaping element, wherein the channels comprise a first plurality of channels that are not perpendicular to a plane defined by the plating face of the substrate and a second plurality of channels that are perpendicular to the plane defined by the plating face of the substrate, and wherein the first plurality of channels and the second plurality of channels are substantially spatially segregated.

2 . The electroplating apparatus of claim 1 , wherein the channels that are not perpendicular to the plane defined by the plating face of the substrate are directed at an angle of between about 30-75 degrees to the plane defined by the plating face of the substrate.

3 . The electroplating apparatus of claim 1 , wherein the first plurality of channels that are not perpendicular to the plane defined by the plating face of the substrate are located in a central portion of the flow-shaping element and are surrounded by the second plurality of channels that are perpendicular to the plane defined by the plating face of the substrate.

4 . The electroplating apparatus of claim 1 , wherein the first plurality of channels occupy a generally rectangular region in a central portion of the flow-shaping element.

5 . The electroplating apparatus of claim 1 , wherein the first plurality of channels occupy a generally circular region in a central portion of the flow-shaping element.

6 . The electroplating apparatus of claim 1 , wherein the flow-shaping element comprises between about 6,000-12,000 channels, and wherein the first plurality of channels is between about 0.5-2% of the total number of channels.

7 . The electroplating apparatus of claim 1 , wherein the first plurality of channels that are not perpendicular to the plane defined by the plating face of the substrate are located in a peripheral portion of the flow-shaping element and surround the second plurality of channels that are perpendicular to the plane defined by the plating face of the substrate.

8 . The electroplating apparatus of claim 1 , wherein the channels from the first plurality of channels have larger diameters than the channels from the second plurality of channels.

9 . The electroplating apparatus of claim 1 , wherein the flow-shaping element is a planar disk.

10 . The electroplating apparatus of claim 1 , wherein the substrate-facing surface of the flow-shaping element is convex.

11 . The apparatus of claim 1 , wherein the substrate-facing surface of the flow-shaping element is separated from the plating face of the substrate by a distance of about 10 millimeters or less during electroplating.

12 . The apparatus of claim 1 , further comprising one or more tubes configured to distribute the electrolyte within the electroplating apparatus, wherein each tube has a plurality of openings in its wall distributed to provide greater flow of electrolyte to a central portion of the plating chamber.

13 . The apparatus of claim 1 , further comprising one or more tubes configured to distribute the electrolyte within the electroplating apparatus, wherein each tube has a plurality of openings in its wall distributed to provide greater flow of electrolyte to a peripheral portion of the plating chamber.

14 . The apparatus of claim 1 , further comprising one or more tubes configured to distribute the electrolyte within the electroplating apparatus, wherein each tube has a plurality of openings in its wall distributed to provide uniform flow of electrolyte to the plating chamber.

15 . A method of electroplating metal on a substrate comprising a plurality of recessed features, the method comprising:
(a) providing the substrate to a plating chamber configured to contain an electrolyte and an anode while electroplating metal onto the substrate, wherein the plating chamber includes:
(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 comprising an ionically resistive material with a plurality of non-communicating channels made through the flow-shaping element, wherein said non-communicating channels allow for transport of the electrolyte through the flow-shaping element during electroplating, wherein the channels comprise a first plurality of channels that are not perpendicular to a plane defined by the plating face of the substrate and a second plurality of channels that are perpendicular to the plane defined by the plating face of the substrate, wherein the first plurality of channels and the second plurality of channels are substantially spatially segregated;
(b) electroplating a metal onto the substrate plating surface while rotating the substrate and while flowing the electrolyte in the electroplating cell in the direction of the substrate plating face through the channels of the flow-shaping element.

16 . The method of claim 15 , wherein the channels that are not perpendicular to the plane defined by the plating face of the substrate are directed at an angle of between about 30-75 degrees to the plane defined by the plating face of the substrate.

17 . The method of claim 15 , wherein the first plurality of channels that are not perpendicular to the plane defined by the plating face of the substrate are located in a central portion of the flow-shaping element and are surrounded by the second plurality of channels that are perpendicular to the plane defined by the plating face of the substrate.

18 . The method of claim 1 , wherein the recessed features are Damascene features having widths of less than about 100 nm.

19 . The method of claim 15 , wherein the electroplating comprises:
(i) electrodepositing copper while providing a first level of power to the plating cell; (ii) reducing power to about zero, and allowing the substrate to rotate at a rate of at least about 200 rpm while no power is applied; (iii) continue electrodepositing copper at a second power level after increasing the power provided to the plating cell from about zero to the second power level, which is greater than the first power level, wherein the electroplating comprises providing electrolyte to the plating cell at a lower rate during (i) than during (iii).

Assignees

• Lam Res Corp

Inventors

• He Zhian
• Zhou Jian
• Feng Jingbin
• Reid Jonathan D
• Ghongadi Shantinath

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

• C25D5/022

  using masking means · CPC title

• C25D17/001

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

• C25D5/04

  Electroplating with moving electrodes · CPC title