Apparatus for plating and method of plating

Abstract

There is provided an apparatus for plating a substrate, comprising: an anode placed to be opposed to the substrate; and an intermediate mask placed between the substrate and the anode to be arranged on a substrate side, provided with a first center opening that causes an electric field from the anode toward the substrate to pass through, and further provided with an auxiliary anode that is placed in an internal space of the intermediate mask to be arranged around the first center opening, wherein the auxiliary anode has an area that is not greater than ⅕ of an area of the anode.

1 . An apparatus for plating a substrate in a rectangular shape, comprising:
 an anode placed to be opposed to the substrate; and   an intermediate mask placed between the substrate and the anode to be arranged on a substrate side, provided with a first center opening that causes an electric field from the anode toward the substrate to pass through, and further provided with an auxiliary anode arranged around the first center opening,   wherein the first center opening of the intermediate mask has a shape corresponding to the shape of the substrate, and   the auxiliary anode is divided into a plurality of auxiliary anodes, the auxiliary anodes being placed along respective sides of four sides of the first center opening at positions other than corners of the first center opening.   
     
     
         2 . The apparatus for plating according to  claim 1 ,
 wherein a distance between the intermediate mask and the substrate is not less than ¼ and not greater than ⅓ of a distance between the anode and the substrate.   
     
     
         3 . The apparatus for plating according to  claim 1 ,
 wherein the intermediate mask comprises:
 a mask main body provided with a second center opening and further provided with an internal space in which the auxiliary anode is placed, the internal space being arranged around the second center opening and the internal space being open on a substrate side thereof; and 
 a shielding plate placed to cover the internal space of the mask main body, provided with a third center opening that is smaller than the second center opening and that defines the first center opening, and further provided with a first opening that overlaps with at least a partial area of the auxiliary anode. 
   
     
     
         4 . The apparatus for plating according to  claim 3 ,
 wherein the shielding plate further includes a diaphragm provided to cover the first opening.   
     
     
         5 . The apparatus for plating according to  claim 1 ,
 wherein the intermediate mask includes an internal space in which the auxiliary anode is paced in, and a passage that causes an electric field from the auxiliary anode toward the substrate to pass through and that has an outlet provided at a position which does not overlap with the auxiliary anode in a plane parallel to the substrate.   
     
     
         6 . The apparatus for plating according to  claim 5 ,
 wherein the intermediate mask comprises:
 a mask main body; 
 a cover mounted to cover a substrate side of the mask main body and configured to form, along with the mask main body, a fourth center opening corresponding to the first center opening; and 
 a block mounted to the mask main body and the cover on a periphery of the fourth center opening, wherein 
   the mask main body includes the internal space and has a second opening that overlaps with at least a partial area of the auxiliary anode,   the cover includes a first passage that communicates with the second opening, and   the block includes a second passage that communicates with the first passage,   wherein the first passage and the second passage form the passage that causes the electric field from the auxiliary anode toward the substrate to pass through.   
     
     
         7 . The apparatus for plating according to  claim 6 ,
 wherein the mask main body is further provided with a diaphragm to cover the second opening.   
     
     
         8 . The apparatus for plating according to  claim 1 , further comprising:
 a variable anode mask configured to regulate an exposed area of the anode.   
     
     
         9 . The apparatus for plating according to  claim 1 ,
 wherein the anode is a split anode consisting of a plurality of anode pieces, wherein   an effective area of the anode that provides the electric field toward the substrate is adjusted by selecting an anode piece which electric current is to flow in, or   the electric field from the anode toward the substrate is adjusted by regulating electric current flowing in each of the anode pieces.   
     
     
         10 . The apparatus for plating according to  claim 1 ,
 wherein the plurality of auxiliary anodes are electrically connected with a bus bar which is connected with a positive electrode of a power source.   
     
     
         11 . A method of plating a substrate in a rectangular shape, comprising:
 providing an intermediate mask that is placed between the substrate and an anode, wherein the intermediate mask comprises a center opening having a shape corresponding to the shape of the substrate and configured to control an electric field from the anode toward the substrate; and a plurality of auxiliary anodes that are placed around the center opening, the plurality of auxiliary anodes being placed along respective sides of four sides of the center opening at positions other than corners of the center opening; and   regulating expansion of the electric field from the anode toward the substrate and regulating electric current that is to be supplied to the auxiliary anode placed in the intermediate mask, according to a resist opening ratio and a magnitude of seed resistance of the substrate.   
     
     
         12 . The method according to  claim 11 ,
 wherein the expansion of the electric field from the anode toward the substrate is adjusted by a variable anode mask that is configured to regulate an exposed area of the anode.   
     
     
         13 . The method according to  claim 11 ,
 wherein the anode is a split anode consisting of a plurality of anode pieces, wherein   the expansion of the electric field from the anode toward the substrate is adjusted by selecting an anode piece which electric current is to flow in or by regulating electric current flowing in each of the anode pieces.   
     
     
         14 . The method according to  claim 11 ,
 wherein the plurality of auxiliary anodes are electrically connected with a bus bar which is connected with a positive electrode of a power source, the plurality of auxiliary anodes being supplied with electric current via the bus bar from the power source.