Apparatus for plating and method of plating

Abstract

An object is to improve the uniformity of a plating film thickness in a variety of different types of apparatuses for plating that perform pulse plating. There is provided an apparatus for plating, comprising: a first plating tank configured to plate a substrate by application of a forward direction current and a reverse current pulse between the substrate and an anode; a first flow path connected with a reservoir tank and configured to discharge a plating liquid from the reservoir tank; a second flow path connected with the first flow path and with the first plating tank and configured to supply the plating liquid to the first plating tank; a third flow path connected with the first flow path and configured to cause the plating liquid discharged from the reservoir tank to go around the first plating tank and to be returned to the reservoir tank or to be discharged to a discharge port; a first valve configured to regulate a flow of the plating liquid between the second flow path and the third flow path; and a control module configured to control the first valve according to a timing of the reverse current pulse during plating of the substrate, such as to regulate the flow of the plating liquid between the second flow path and the third flow path and to decrease a supply of the plating liquid to the second flow path to be less than a supply of the plating liquid in an interval of the forward direction current or to stop the supply of the plating liquid to the second flow path.

What is claimed is: 
     
         1 . An apparatus for plating, comprising:
 a first plating tank configured to plate a substrate by application of a forward direction current and a reverse current pulse between the substrate and an anode;   a first flow path connected with a reservoir tank and configured to discharge a plating liquid from the reservoir tank;   a second flow path connected with the first flow path and with the first plating tank and configured to supply the plating liquid to the first plating tank;   a third flow path connected with the first flow path and configured to cause the plating liquid discharged from the reservoir tank to go around the first plating tank and to be returned to the reservoir tank or to be discharged to a discharge port;   a first valve configured to regulate a flow of the plating liquid between the second flow path and the third flow path; and   a control module configured to control the first valve according to a timing of the reverse current pulse during plating of the substrate, such as to regulate the flow of the plating liquid between the second flow path and the third flow path and to decrease a supply of the plating liquid to the second flow path to be less than a supply of the plating liquid in an interval of the forward direction current or to stop the supply of the plating liquid to the second flow path.   
     
     
         2 . The apparatus for plating according to  claim 1 ,
 wherein the first valve comprises a flow path changeover valve connected with the first flow path, the second flow path and the third flow path and configured to change over a flow passage between the second flow path and the third flow path.   
     
     
         3 . The apparatus for plating according to  claim 2 ,
 wherein the flow path changeover valve is a three-way valve.   
     
     
         4 . The apparatus for plating according to  claim 1 ,
 wherein the first valve is provided in the second flow path.   
     
     
         5 . The apparatus for plating according to  claim 1 ,
 wherein the first valve is provided in the third flow path.   
     
     
         6 . The apparatus for plating according to  claim 1 , further comprising:
 a second valve, wherein   the first valve is provided in the second flow path,   the second valve is provided in the third flow path, and   the first valve and the second valve are controlled by the control module to be operated at an identical timing.   
     
     
         7 . The apparatus for plating according to  claim 4 ,
 wherein the first valve comprises at least one of a flow control valve and an on-off valve.   
     
     
         8 . The apparatus for plating according to  claim 1 , further comprising:
 a second plating tank; and   a fourth flow path branched off from the second flow path toward the second plating tank, wherein   the control module controls the first valve according to the timing of the reverse current pulse during plating of the substrate, so as to decrease supplies of the plating liquid to the first plating tank and to the second plating tank to be less than supplies of the plating liquid in the interval of the forward direction current or to stop the supplies of the plating liquid to the first plating tank and to the second plating tank.   
     
     
         9 . The apparatus for plating according to  claim 1 , further comprising:
 a second plating tank;   a fourth flow path branched off from the first flow path toward the second plating tank on an upstream side of a location where the third flow path is connected with the first flow path;   a fifth flow path connected with the fourth flow path and configured to cause the plating liquid discharged from the reservoir tank to go around the second plating tank and to be returned to the reservoir tank or to be discharged to a discharge port; and   a third valve configured to regulate a flow of the plating liquid between the fourth flow path and the fifth flow path, wherein   the control module further controls the third valve according to the timing of the reverse current pulse during plating of the substrate, such as to regulate the flow of the plating liquid between the fourth flow path and the fifth flow path and to decrease a supply of the plating liquid to the fourth flow path to be less than a supply of the plating liquid in the interval of the forward direction current or to stop the supply of the plating liquid to the fourth flow path.   
     
     
         10 . The apparatus for plating according to  claim 1 , further comprising:
 a flowmeter configured to detect a flow rate of the plating liquid in the second flow path, wherein   when it is determined that a timing of decreasing the flow rate of the plating liquid in the second flow path is deviated from a desired timing according to the timing of the reverse current pulse, based on the flow rate detected by the flowmeter, the control module performs feedback control of a timing of controlling the first valve, such as to reduce the deviation of the timing.   
     
     
         11 . An apparatus for plating, comprising:
 a plating tank configured to plate a substrate by application of a forward direction current and a reverse current pulse between the substrate and an anode;   a first flow path connected with a reservoir tank and configured to discharge a plating liquid from the reservoir tank;   a second flow path and a third flow path fluidically connected with the first flow path and with the plating tank and provided parallel to each other, wherein the second flow path has a larger inner diameter than an inner diameter of the third flow path;   a first valve provided in the second flow path;   a second valve provided in the third flow path; and   a control module configured to control the first valve and the second valve according to a timing of the reverse current pulse during plating of the substrate, such as to regulate a flow of the plating liquid between the second flow path and the third flow path and to decrease a total flow rate of the plating liquid through the second flow path and through the third flow path to be less than a total flow rate of the plating liquid in an interval of the forward direction current.   
     
     
         12 . The apparatus for plating according to  claim 11 , further comprising:
 one or a plurality of flowmeters configured to detect the total flow rate of the plating liquid through the second flow path and through the third flow path, wherein   when it is determined that a timing of decreasing the total flow rate of the plating liquid through the second flow path and through the third flow path is deviated from a desired timing according to the timing of the reverse current pulse, based on the total flow rate detected by the one or the plurality of flowmeters, the control module performs feedback control of a timing of controlling the first valve and the second valve, such as to reduce the deviation of the timing.   
     
     
         13 . An apparatus for plating, comprising:
 a plating tank;   an anode placed in the plating tank;   a substrate holder configured to hold a substrate such as to be opposed to the anode;   a resistor placed between the substrate holder and the anode and provided with a plurality of through holes that form a flow path of a plating liquid;   a lift device configured to lift up and down the substrate holder;   a power source configured to apply a forward direction current and a reverse current pulse between the substrate and the anode; and   a control module, wherein   the plating tank is configured to supply the plating liquid to the substrate via the resistor and to supply the plating liquid along a surface of the substrate in such a manner as to shear the plating liquid supplied to the substrate via the resistor, and   the control module is configured to control the lift device according to a timing of the reverse current pulse during plating of the substrate, such as to lift up the substrate holder, to expand a flow passage area of the plating liquid between the substrate and the resistor, and to weaken a flow of the plating liquid on the surface of the substrate, compared with a flow of the plating liquid in an interval of the forward direction current.   
     
     
         14 . The apparatus for plating according to  claim 13 ,
 wherein the control module obtains a height of the substrate holder, and   when it is determined that a timing of increasing the height of the substrate holder is deviated from a desired timing according to the timing of the reverse current pulse, based on the obtained height of the substrate holder, the control module performs feedback control of a timing of controlling the lift device, such as to reduce the deviation of the timing.   
     
     
         15 . A method of plating a substrate in a plating tank by application of a forward direction current and a reverse current pulse between the substrate and an anode, the method comprising:
 providing an apparatus for plating, which comprises: a plating tank; a first flow path connected with a reservoir tank and configured to discharge a plating liquid from the reservoir tank; a second flow path connected with the first flow path and with the plating tank and configured to supply the plating liquid to the plating tank; a third flow path connected with the first flow path and configured to cause the plating liquid discharged from the reservoir tank to go around the plating tank and to be returned to the reservoir tank or to be discharged to a discharge port; and a first valve configured to regulate a flow of the plating liquid between the second flow path and the third flow path; and   controlling the first valve according to a timing of the reverse current pulse during plating of the substrate, such as to decrease a supply of the plating liquid to the second flow path to be less than a supply of the plating liquid in an interval of the forward direction current or to stop the supply of the plating liquid to the second flow path.   
     
     
         16 . A method of plating a substrate in a plating tank by application of a forward direction current and a reverse current pulse between the substrate and an anode, the method comprising:
 providing an apparatus for plating, which comprises: a plating tank; a first flow path connected with a reservoir tank and configured to discharge a plating liquid from the reservoir tank; a second flow path and a third flow path fluidically connected with the first flow path and with the plating tank and provided parallel to each other, wherein the second flow path has a larger inner diameter than an inner diameter of the third flow path; a first valve provided in the second flow path; and a second valve provided in the third flow path; and   controlling the first valve and the second valve according to a timing of the reverse current pulse during plating of the substrate, such as to regulate a flow of the plating liquid between the second flow path and the third flow path and to decrease a total flow rate of the plating liquid through the second flow path and through the third flow path to be less than a total flow rate of the plating liquid in an interval of the forward direction current.   
     
     
         17 . A method of plating a substrate in a plating tank by application of a forward direction current and a reverse current pulse between the substrate and an anode, the method comprising:
 providing an apparatus for plating, which comprises: a plating tank; an anode placed in the plating tank; a substrate holder configured to hold a substrate such as to be opposed to the anode; a resistor placed between the substrate holder and the anode and configured to form a flow path of a plating liquid between the resistor and the substrate; and a lift device configured to lift up and down the substrate holder, wherein the plating tank is configured to supply the plating liquid to the substrate via the resistor and to supply the plating liquid along a surface of the substrate in such a manner as to shear the plating liquid supplied to the substrate via the resistor; and   controlling the lift device according to a timing of the reverse current pulse during plating of the substrate, such as to lift up the substrate holder, to expand a flow passage area of the plating liquid between the substrate and the resistor, and to weaken a flow of the plating liquid on the surface of the substrate, compared with a flow of the plating liquid in an interval of the forward direction current.   
     
     
         18 . A storage medium configured to store therein a program that causes a computer to perform a control method of plating a substrate by application of a forward direction current and a reverse current pulse between the substrate and an anode in an apparatus for plating, the apparatus for plating comprising: a plating tank; a first flow path connected with a reservoir tank and configured to discharge a plating liquid from the reservoir tank; a second flow path connected with the first flow path and with the plating tank and configured to supply the plating liquid to the plating tank; a third flow path connected with the first flow path and configured to cause the plating liquid discharged from the reservoir tank to go around the plating tank and to be returned to the reservoir tank or to be discharged to a discharge port; and a first valve configured to regulate a flow of the plating liquid between the second flow path and the third flow path,
 wherein the program causes the computer to perform:   controlling the first valve according to a timing of the reverse current pulse during plating of the substrate, such as to regulate the flow of the plating liquid between the second flow path and the third flow path and to decrease a supply of the plating liquid to the second flow path to be less than a supply of the plating liquid in an interval of the forward direction current or to stop the supply of the plating liquid to the second flow path.   
     
     
         19 . A storage medium configured to store therein a program that causes a computer to perform a control method of plating a substrate by application of a forward direction current and a reverse current pulse between the substrate and an anode in an apparatus for plating, the apparatus for plating comprising: a plating tank; a first flow path connected with a reservoir tank and configured to discharge a plating liquid from the reservoir tank; a second flow path and a third flow path fluidically connected with the first flow path and with the plating tank and provided parallel to each other, wherein the second flow path has a larger inner diameter than an inner diameter of the third flow path; a first valve provided in the second flow path; and a second valve provided in the third flow path,
 wherein the program causes the computer to perform:   controlling the first valve and the second valve according to a timing of the reverse current pulse during plating of the substrate, such as to regulate a flow of the plating liquid between the second flow path and the third flow path and to decrease a total flow rate of the plating liquid through the second flow path and through the third flow path to be less than a total flow rate of the plating liquid in an interval of the forward direction current.   
     
     
         20 . A storage medium configured to store therein a program that causes a computer to perform a control method of plating a substrate by application of a forward direction current and a reverse current pulse between the substrate and an anode in an apparatus for plating, the apparatus for plating comprising: a plating tank; an anode placed in the plating tank; a substrate holder configured to hold a substrate such as to be opposed to the anode; a resistor placed between the substrate holder and the anode and provided with a plurality of through holes that form a flow path of a plating liquid; and a lift device configured to lift up and down the substrate holder, wherein the plating tank is configured to supply the plating liquid to the substrate via the resistor and to supply the plating liquid along a surface of the substrate in such a manner as to shear the plating liquid supplied to the substrate via the resistor,
 wherein the program causes the computer to perform:   controlling the lift device according to a timing of the reverse current pulse during plating of the substrate, such as to lift up the substrate holder, to expand a flow passage area of the plating liquid between the substrate and the resistor, and to weaken a flow of the plating liquid on the surface of the substrate, compared with a flow of the plating liquid in an interval of the forward direction current.