Cross flow conduit for foaming prevention in high convection plating cells

Patent metadata

Field	Value
Publication number	US-2021395913-A1
Application number	US-201917309214-A
Country	US
Kind code	A1
Filing date	Nov 15, 2019
Priority date	Nov 19, 2018
Publication date	Dec 23, 2021
Grant date	—

Abstract

The embodiments herein relate to apparatuses and methods for electroplating one or more materials onto a substrate. Embodiments herein utilize a cross flow conduit in the electroplating cell to divert flow of fluid from a region between a substrate and a channeled ionically resistive plate positioned near the substrate down to a level lower than level of fluid in a fluid containment unit for collecting overflow fluid from the plating system for recirculation. The cross flow conduit can include channels cut into components of the plating cell to allow diverted flow, or can include an attachable diversion device mountable to an existing plating cell to divert flow downwards to the fluid containment unit. Embodiments also include a flow restrictor which may be a plate or a pressure relief valve for modulating flow of fluid in the cross flow conduit during plating.

First claim

1 . An electroplating apparatus comprising:
an electroplating cell configured to contain an electrolyte and an anode while electroplating metal onto a substrate, the electroplating cell having a chamber wall of a fluid containment unit having a fluid level during electroplating; a substrate holder configured to hold the substrate such that a plating face of the substrate is separated from the anode during electroplating; a channeled ionically resistive plate including a substrate-facing surface that is separated from the plating face of the substrate by a cross flow region; a cross flow inlet to the cross flow region for providing electrolyte to the cross flow region; and a cross flow conduit comprising a channel for diverting electrolyte from the cross flow region to an outlet feeding the fluid containment unit of the electroplating cell, the outlet being lower than the fluid level and the cross flow region being between the cross flow inlet and cross flow conduit.

2 . The electroplating apparatus of claim 1 , wherein the cross flow region is defined at least in part by an upper surface of the channeled ionically resistive plate and a lower surface of the substrate in the substrate holder when in operation, and an insert.

3 . The electroplating apparatus of claim 1 , wherein the cross flow conduit is disposed to accept electrolyte flowing out of the cross flow region and direct the electrolyte flowing out downward and away from a surface of the substrate.

4 . The electroplating apparatus of claim 1 , further comprising a flow restrictor for restricting flow of electrolyte in the cross flow conduit.

5 . The electroplating apparatus of claim 4 , wherein the flow restrictor is one of:
a plate inserted under the channeled ionically resistive plate, a motor-driven variable aperture plate capable of varying an opening size of the cross flow conduit, or a pressure relief valve controlling flow of electrolyte through the cross flow conduit depending on pressure of the electrolyte in response to whether a substrate is present in the electroplating cell.

6 . The electroplating apparatus of claim 5 , further comprising a controller comprising executable instructions for electroplating material onto the substrate by:
causing flow of electrolyte via cross flow across a surface of the substrate from one side of the substrate to the opposite side of the substrate; causing diversion of flow of electrolyte to below fluid level as electrolyte flows to the opposite side of the substrate for collection in fluid containment unit; and causing widening and narrowing of an opening of the cross flow conduit using the motor-driven variable aperture plate in response to flow rate of electrolyte.

7 . The electroplating apparatus of claim 1 , wherein the cross flow conduit is an attachable diversion device capable of being attached to the electroplating cell.

8 . The electroplating apparatus of claim 1 , further comprising a membrane frame below the channeled ionically resistive plate, wherein the cross flow conduit further comprises a second channel in the membrane frame for flowing electrolyte from the cross flow region to an outlet to the fluid containment unit of the electroplating cell.

9 . The electroplating apparatus of claim 1 , further comprising a weir wall.

10 . A method for electroplating on a substrate in an electroplating cell, the method comprising:
receiving a substrate in a substrate holder, where the substrate holder is configured to hold the substrate such that a plating face of the substrate is separated from an anode during electroplating; immersing the substrate in electrolyte, where a cross flow region is formed between the plating face of the substrate and an upper surface of a channeled ionically resistive plate; flowing electrolyte in contact with the substrate in the substrate holder from below the channeled ionically resistive plate, across the channeled ionically resistive plate through the cross flow region, and out a cross flow conduit; modulating an opening of the cross flow conduit using a flow restrictor; and electroplating material onto the plating face of the substrate while flowing electrolyte and while modulating the opening of the cross flow conduit.

11 . The method of claim 10 , wherein the electroplating cell comprises a fluid containment unit for holding electrolyte after it has passed through the cross flow region, wherein the fluid containment unit has a fluid level during electroplating, wherein the cross flow conduit comprises a channel for diverting electrolyte from the cross flow region to an outlet feeding the fluid containment unit, and wherein the outlet is lower than the fluid level in the fluid containment unit.

12 . The method of claim 10 , wherein the cross flow conduit is disposed to accept electrolyte flowing out of the cross flow region and direct the electrolyte flowing out downward and away from a surface of the substrate.

13 . The method of claim 10 , wherein the flow restrictor comprises a motor-driven variable aperture plate capable of varying a size of the opening to the cross flow conduit, and wherein modulating an opening of the cross flow conduit comprises engaging the motor-driven variable aperture plate.

14 . The method of claim 10 , wherein the flow restrictor comprises a pressure relief valve that seals flow of electrolyte depending on a pressure of the electrolyte in response to whether a substrate is present in the electroplating cell, and wherein modulating the opening of the cross flow conduit comprises modulating the pressure relief valve.

15 . The method of claim 10 , wherein the cross flow conduit comprises an attachable diversion device capable of being attached to the electroplating cell.

16 . The method of claim 10 , wherein the electroplating cell comprises a membrane frame having an opening, wherein the cross flow conduit is defined, at least in part, by the opening in the membrane frame, and wherein flowing electrolyte out the cross flow conduit comprises flowing electrolyte through the opening in the membrane frame.

17 . The method of claim 10 , wherein during electroplating, the cross flow conduit prevents electrolyte from flowing over a weir wall of the electroplating cell.

18 . A method for electroplating on a substrate in an electroplating cell, the method comprising:
receiving a substrate in a substrate holder, where the substrate holder is configured to hold the substrate such that a plating face of the substrate is separated from an anode during electroplating; immersing the substrate in electrolyte, where a cross flow region is formed between the plating face of the substrate and an upper surface of a channeled ionically resistive plate; and flowing electrolyte in contact with the substrate in the substrate holder from below the channeled ionically resistive plate, across the channeled ionically resistive plate through the cross flow region, through a cross flow conduit, and through an outlet feeding a fluid containment unit, wherein the fluid containment unit has a fluid level during electroplating, and wherein the outlet feeding the fluid containment unit is lower than the fluid level in the fluid containment unit.

19 . The method of claim 18 , wherein the channeled ionically resistive plate comprises an opening, and wherein the cross flow conduit is defined, at least in part, by the opening in the channeled ionically resistive plate.

20 . The method of claim 18 , wherein the cross flow conduit comprises an at

Assignees

• Lam Res Corp

Inventors

• Banik Ii Stephen J
• Berke Aaron
• Graham Gabriel Hay
• Kearns Gregory J
• Chua Lee Peng
• Buckalew Bryan L

Classifications

• C25D21/12

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

• C25D17/06

  Suspending or supporting devices for articles to be coated · CPC title

• C25D17/02 Primary

  Tanks; Installations therefor · CPC title

• C25D7/123

  Semiconductors first coated with a seed layer or a conductive layer · CPC title

• C25D17/008

  Current shielding devices · CPC title