Electroplating apparatus and method

Abstract

An apparatus and a method for plating a substrate are provided. The apparatus includes: an electroplating cell for containing an electroplating solution; a substrate holder for holding a substrate in the electroplating solution; a rotation driver coupled to the substrate holder and configured to rotate the substrate holder; a power distribution assembly coupled to the rotation driver; an anode disposed within the electroplating cell; a power supply unit electrically coupled between the anode and the power distribution assembly, thereby forming an electric loop; and a current regulating member for providing a predetermined impedance value for the electric loop, wherein a voltage provided by the power supply unit causes an electric current to flow through the electric loop, and the predetermined impedance is such selected that the variation of the electric current is kept within a smaller range compared to that measured in the absence of the current regulating member.

What is claimed is: 
     
         1 . An electroplating apparatus for electrochemically plating a substrate, comprising:
 an electroplating cell for containing an electroplating solution;   a substrate holder for holding a substrate in the electroplating solution;   a rotation driver electrically coupled to the substrate holder and configured to rotate the substrate holder;   a power distribution assembly electrically coupled to the rotation driver;   an anode disposed within the electroplating cell, the anode being immersed in the electroplating solution;   a power supply unit electrically coupled between the anode and the power distribution assembly, thereby forming an electric loop; and   a current regulating member for providing a predetermined impedance value for the electric loop,   wherein a voltage provided by the power supply unit causes an electric current to flow through the electric loop, and the predetermined impedance is such selected that the variation of the electric current flowing through the electric loop is kept within a smaller range compared to that measured in the absence of the current regulating member.   
     
     
         2 . The electroplating apparatus of  claim 1 , wherein the anode is made of gold, zinc, nickel, silver, copper or nickel. 
     
     
         3 . The electroplating apparatus of  claim 1 , wherein the rotation driver comprises a rotatable spindle and a slip ring assembly. 
     
     
         4 . The electroplating apparatus of  claim 1 , wherein the power supply unit comprises a DC power supply unit. 
     
     
         5 . The electroplating apparatus of  claim 1 , wherein the current regulating member is arranged on the electric loop and is not disposed in the electroplating cell. 
     
     
         6 . The electroplating apparatus of  claim 1 , wherein the predetermined impedance value ranges from about 0.02 mΩ to about 20Ω. 
     
     
         7 . The electroplating apparatus of  claim 1 , wherein the predetermined impedance value ranges from about 0.05 mΩ to about 5Ω. 
     
     
         8 . The electroplating apparatus of  claim 1 , wherein the predetermined impedance value ranges from about 0.1 mΩ to about 1Ω. 
     
     
         9 . The electroplating apparatus of  claim 1 , wherein the impedance of the electric loop ranges from 1Ω to 50Ω. 
     
     
         10 . An electroplating apparatus for electrochemically plating a substrate, comprising:
 an electroplating cell for containing an electroplating solution;   a substrate holder for holding a substrate in the electroplating solution;   a rotation driver electrically coupled to the substrate holder and configured to rotate the substrate holder;   an anode disposed within the electroplating cell, the anode being immersed in the electroplating solution, wherein a voltage applied across the rotation driver and the anode causes an electric current to flow from the rotation driver to the anode; and   a current regulating member electrically coupled to the rotation driver, wherein a predetermined impedance value of the current regulating member is such selected that the variation in the electric current is kept within a smaller range compared to that measured in the absence of the current regulating member.   
     
     
         11 . The electroplating apparatus of  claim 10 , wherein the substrate holder comprises a clamshell-type substrate holder. 
     
     
         12 . The electroplating apparatus of  claim 12 , wherein the clamshell-type substrate holder comprises a cone member, a cup member and a seal member. 
     
     
         13 . An electroplating method for electrochemically plating a substrate, comprising:
 immersing a substrate into an electroplating solution;   electrically coupling an anode to the electroplating solution;   forming an electric loop in which an electric current flows from a power supply to the anode, the electroplating solution, the substrate, and back to the power supply; and   providing a current regulating member with a predetermined impedance value on the electric loop,   wherein the predetermined impedance is such selected that the variation of the electric current flowing through the electric loop is kept within a smaller range compared to that measured in the absence of the current regulating member,   wherein the flow of the electric current through the electric loop causes the deposition of a conductive material onto the substrate.   
     
     
         14 . The method of  claim 13 , wherein the predetermined impedance value ranges from about 0.1 mΩ to about 1Ω. 
     
     
         15 . The method of  claim 13 , wherein the operation of immersing the substrate into the electroplating solution further comprises rotating the substrate in the electroplating solution. 
     
     
         16 . The method of  claim 13 , wherein the electroplating solution comprises copper sulfate or copper cyanide. 
     
     
         17 . The method of  claim 13 , wherein the electroplating solution comprises at least one of a brightener, suppressor and leveler. 
     
     
         18 . The method of  claim 13 , wherein an operation of forming additional conductive layers is performed prior to immersing the substrate into the electroplating solution. 
     
     
         19 . The method of  claim 18 , wherein the conductive layers comprise a barrier layer and a seed layer. 
     
     
         20 . The method of  claim 13  further comprising planarizing a plated surface of the substrate by chemical mechanical polishing (CMP).