Control of dissolved gas concentration in electroplating baths

Patent metadata

Field	Value
Publication number	US-2024200223-A1
Application number	US-202218554622-A
Country	US
Kind code	A1
Filing date	Apr 14, 2022
Priority date	Apr 15, 2021
Publication date	Jun 20, 2024
Grant date	—

Abstract

A concentration of a dissolved gas can be controlled by following an electroplating solution through a contactor, controlling a pressure within the contactor, and thereby maintaining the concentration of the dissolved gas in the electroplating solution within a first concentration range. The first concentration range is non-zero and sub-saturation.

First claim

What is claimed is:

1 . A method of controlling a concentration of a dissolved gas in an electroplating solution of an electroplating system having one or more electroplating cells, a contactor having a membrane with a shell side and a lumen side, and being fluidically connected to the one or more electroplating cells, a vacuum source connected to the contactor and configured to apply a vacuum to the contactor, the method comprising:
flowing the electroplating solution through the contactor; and controlling a pressure within the contactor and thereby maintaining the concentration of the dissolved gas in the electroplating solution within a first concentration range that is non-zero and sub-saturation.

2 . The method of claim 1 , wherein:
the controlling includes increasing the pressure in the contactor and thereby increasing the concentration, and the controlling includes decreasing the pressure in the contactor and thereby decreasing the concentration.

3 . The method of claim 2 , wherein:
the electroplating system further includes a valve that is interposed between the vacuum source and the contactor, configured to stop the applying of the vacuum to the contactor when closed, and configured to enable application of the vacuum to the contactor when open, the increasing the pressure further includes closing the valve to stop applying the vacuum to the contactor, and the decreasing the pressure further includes opening the valve to apply the vacuum to the contactor.

4 . The method of claim 3 , further comprising detecting the pressure within the contactor using a pressure sensor, wherein:
the controlling further includes opening the valve, in response to detecting a first pressure in the contactor, and thereby decreasing the pressure within the contactor, and the controlling further includes closing the valve, in response to detecting a second pressure in the contactor lower than the first pressure, and thereby increasing the pressure within the contactor.

5 . The method of claim 3 , further comprising detecting a gas concentration of the electroplating solution using a gas sensor, wherein:
the controlling further includes opening the valve, in response to detecting a first gas concentration, and thereby decreasing the pressure within the contactor, and the controlling further includes closing the valve, in response to detecting a second gas concentration lower than the first gas concentration, and thereby increasing the pressure within the contactor.

6 . The method of claim 5 , wherein:
the dissolved gas is oxygen, and the gas sensor is an oxygen sensor.

7 . The method of claim 3 , wherein the controlling further includes:
opening and closing the valve at a first frequency when one or more of the electroplating cells have a wafer positioned therein, and opening and closing the valve at a second frequency greater than the first frequency when one or more of the electroplating cells do not have a wafer positioned therein.

8 . The method of claim 3 , wherein the controlling further includes:
opening and closing the valve at a first frequency when electroplating is being performed on a wafer one of the electroplating cells, and opening and closing the valve at a second frequency different than the first frequency when one or more of the electroplating is not being performed in one of the electroplating cells.

9 . The method of claim 1 , wherein the concentration of the electroplating solution has a substantially positive correlation to the pressure in the contactor.

10 . The method of claim 1 , wherein:
the controlling further includes repeatedly increasing and decreasing the pressure within the contactor and thereby maintaining the pressure within a first pressure range, and the first pressure range corresponds with the first concentration range.

11 . The method of claim 1 , wherein:
the electroplating system further includes a pressure regulator connected to the contactor, the controlling further includes maintaining the pressure within a first pressure range that corresponds with the first concentration range.

12 . The method of claim 1 , wherein the first concentration range is between about 2 ppm and about 8 ppm.

13 . The method of claim 1 , wherein the controlling includes maintaining the pressure within a first pressure range between about 0.2 atmosphere and about 1 atmosphere.

14 . The method of claim 1 , wherein the dissolved gas is oxygen.

15 . The method of claim 1 , wherein the controlling further includes:
maintaining, when one or more of the electroplating cells have a wafer positioned therein, the pressure within the contactor to a first pressure range and thereby causing the concentration to be maintained within the first concentration range, and maintaining, when one or more of the electroplating cells do not have a wafer positioned therein, the pressure within the contactor to a second pressure range and thereby causing the concentration to be maintained within a second concentration range that is non-zero, sub-saturation, and different than the first concentration range.

16 . The method of claim 1 , wherein the controlling further includes:
maintaining, when electroplating is being performed on a wafer in one of electroplating cells, the pressure within the contactor to a first pressure range and thereby causing the concentration to be maintained within the first concentration range, and maintaining, when electroplating is being performed on a wafer in one of electroplating cells, the pressure within the contactor to a second pressure range and thereby causing the concentration to be maintained within a second concentration range that is non-zero, sub-saturation, and different than the first concentration range.

17 . An electroplating system comprising:
one or more electroplating cells; a contactor having a membrane with a shell side and a lumen side, and being fluidically connected to the one or more electroplating cells; an electroplating solution having a concentration of dissolved gas; a pump configured to pump the electroplating solution between the one or more electroplating cells and the contactor; a vacuum source connected to the contactor and configured to apply a vacuum to the contactor; and a controller with instructions that are configured to:
cause the electroplating solution to flow through the contactor; and
control a pressure within the contactor and thereby maintain the concentration of dissolved gas in the electroplating solution within a first concentration range that is non-zero and sub-saturation.

18 . The electroplating system of claim 17 , wherein the control of the pressure further includes:
increasing the pressure in the contactor and thereby increasing the concentration, and decreasing the pressure in the contactor and thereby decreasing the concentration.

19 . The electroplating system of claim 17 , further comprising: a valve that is:
interposed between the vacuum source and the contactor, configured to stop an application of the vacuum to the contactor when closed, and configured to enable the application of the vacuum to the contactor when open, wherein the control of the pressure further includes:
closing the valve to stop the application of the vacuum to the contactor and thereby increase the pressure in the contactor, and
opening the valve to apply the vacuum to the contactor and thereby decrease the pressure in the contactor.

20 . The electroplating system of claim

Assignees

• Lam Res Corp

Inventors

• Kearns Gregory J
• Blickensderfer Jacob Kurtis
• Venkatraman Kailash
• Wilmot Frederick Dean
• Chua Lee Peng
• Rash Robert

Classifications

• C25D21/18

  of electrolytes (C25D21/22 takes precedence) · CPC title

• C25D21/12 Primary

  Process control or regulation (controlling or regulating in general G05) · CPC title

• C25D17/001

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

• C25D5/02

  Electroplating of selected surface areas · CPC title

• C25D3/38

  of copper · CPC title