Substrate holder, apparatus for plating, and method of plating

Abstract

There is provided a substrate holder configured to hold a substrate such that the substrate is exposed to and is brought into contact with a plating solution to be plated. The substrate holder comprises a contact that comes into contact with a seed layer formed on a surface of the substrate to feed electricity; a protective electrode that is biased to a higher potential side relative to the contact or that comprises a material having a lower spontaneous potential than a spontaneous potential of the seed layer and that is electrically connected with the seed layer directly or via an electrical conductor; and a holder main body provided with an internal space being configured to place therein an outer circumferential portion of the substrate, the contact and the protective electrode such as to be sealed from outside of the substrate holder in a state that the substrate is held by the substrate holder and configured to store therein a liquid that covers at least part of the protective electrode and at least a contact location between the seed layer and the contact.

What is claimed is: 
     
         1 . A substrate holder configured to hold a substrate such that the substrate is exposed to and is brought into contact with a plating solution to be plated, the substrate holder comprising:
 a contact that comes into contact with a seed layer formed on a surface of the substrate to feed electricity;   a protective electrode that is biased to a higher potential side relative to the contact or that comprises a material having a lower spontaneous potential than a spontaneous potential of the seed layer and that is electrically connected with the seed layer directly or via an electrical conductor; and   a holder main body provided with an internal space, the internal space being configured to place therein an outer circumferential portion of the substrate, the contact and the protective electrode such as to be sealed from outside of the substrate holder in a state that the substrate is held by the substrate holder and configured to store therein a liquid that covers at least part of the protective electrode and at least a contact location between the seed layer and the contact.   
     
     
         2 . The substrate holder according to  claim 1 ,
 wherein the protective electrode is an insoluble electrode and is biased to the higher potential side relative to the contact.   
     
     
         3 . The substrate holder according to  claim 2 ,
 wherein a voltage larger than a difference between the spontaneous potential of the protective electrode and the spontaneous potential of the seed layer is applied to between the protective electrode and the seed layer.   
     
     
         4 . The substrate holder according to  claim 2 ,
 wherein the protective electrode is fixed to the contact via a spacer.   
     
     
         5 . The substrate holder according to  claim 1 ,
 wherein the protective electrode has a lower spontaneous potential than the spontaneous potential of the seed layer, is electrically connected with the seed layer directly or via an electrical conductor and serves as a soluble sacrificial electrode.   
     
     
         6 . The substrate holder according to  claim 5 ,
 wherein the protective electrode is fixed to the contact and is electrically connected with the seed layer via the contact.   
     
     
         7 . The substrate holder according to  claim 1 ,
 wherein the protective electrode is a soluble electrode and is biased to the higher potential side relative to the contact.   
     
     
         8 . The substrate holder according to  claim 7 ,
 wherein the protective electrode is fixed to the contact via a spacer.   
     
     
         9 . The substrate holder according to  claim 1 ,
 wherein the protective electrode is provided continuously or discretely in a location surrounding an outer circumference of the substrate, when the substrate is held by the substrate holder.   
     
     
         10 . The substrate holder according to  claim 1 ,
 wherein the protective electrode is arranged circumferentially such as to have a distance from an edge of the substrate that is not longer than a predetermined distance, when the substrate is held by the substrate holder.   
     
     
         11 . The substrate holder according to  claim 1 ,
 wherein the liquid comprises a liquid having a conductivity of not higher than 1000 μS/cm.   
     
     
         12 . The substrate holder according to  claim 1 ,
 wherein the liquid is pure water, or deaerated or inert gas-replaced pure water.   
     
     
         13 . The substrate holder according to  claim 1 ,
 wherein the protective electrode serves as a detector, wherein   the detector is configured to monitor an electric current flowing between the protective electrode and the contact or a wiring having electrical continuity with the contact in a state that the liquid is introduced into the internal space, and thereby detect a leakage of the plating solution into the internal space.   
     
     
         14 . The substrate holder according to  claim 1 , the substrate holder being applied for a horizontal plating module configured to hold the substrate at a position in a horizontal direction or being applied for a vertical plating module configured to hold the substrate at a position in a vertical direction. 
     
     
         15 . An apparatus for plating, comprising:
 the substrate holder according to  claim 1 ;   a liquid supply module configured to supply a liquid to the internal space of the substrate holder; and   a plating module configured to cause the substrate held by the substrate holder to be exposed to and brought into contact with a plating solution and thereby to be plated.   
     
     
         16 . The apparatus for plating according to  claim 15 ,
 wherein the liquid supply module comprises a cleaning nozzle configured to clean the internal space of the substrate holder and to replace the liquid present in the internal space.   
     
     
         17 . The apparatus for plating according to  claim 15 , further comprising:
 a pre-wet module configured to process the substrate by a pre-wet process, wherein   the plating module causes the substrate in a wet state to be held by the substrate holder.   
     
     
         18 . A method of plating a substrate, the method comprising:
 providing a substrate holder provided with a protective electrode that is biased to a higher potential side relative to a contact which is brought into contact with a seed layer formed on a surface of the substrate to feed electricity, or that comprises a material having a lower spontaneous potential than a spontaneous potential of the seed layer of the substrate and that is electrically connected with the seed layer directly or via an electrical conductor;   introducing a liquid into an internal space of the substrate holder, which places therein an outer circumferential portion of the substrate such as to be sealed from outside, so as to cover at least part of the protective electrode and at least a contact location between the contact of the substrate holder and the seed layer of the substrate, with the liquid in the internal space; and   plating the substrate held by the substrate holder in a state that the liquid is introduced into the internal space of the substrate holder.