Plating apparatus

Abstract

Proposed is a plating apparatus capable of detecting a film thickness of a plating film formed on a substrate during a plating process. The plating apparatus includes a plating tank, a substrate holder configured to hold a substrate, an anode disposed in the plating tank to oppose the substrate held by the substrate holder, a resistor disposed between the substrate and the anode to adjust an electric field, a first detection electrode disposed in a region between a surface to be plated of the substrate and the anode and having an electrode end disposed at a first position inside the resistor, a second detection electrode disposed at a second position where there is less change in potential as compared with the first position in the plating tank, and a controller that measures a potential difference between the first detection electrode and the second detection electrode, to estimate a thickness of a plating film on the substrate based on the potential difference.

1 . A plating apparatus comprising:
 a plating tank;   a substrate holder configured to hold a substrate;   an anode disposed in the plating tank to oppose the substrate held by the substrate holder;   a resistor disposed between the substrate and the anode to adjust an electric field;   a first detection electrode disposed in a region between a surface to be plated of the substrate and the anode and having an electrode end disposed at a first position inside the resistor;   a second detection electrode disposed at a second position where there is less change in potential as compared with the first position in the plating tank; and   a controller that measures a potential difference between the first detection electrode and the second detection electrode, to estimate a thickness of a plating film on the substrate based on the potential difference during a plating process.   
     
     
         2 . The plating apparatus according to  claim 1 ,
 wherein the resistor has a facing surface that faces the surface to be plated of the substrate, and   the first detection electrode is disposed in a groove portion formed in the facing surface.   
     
     
         3 . The plating apparatus according to  claim 1 , further comprising:
 a rotation mechanism that rotates the substrate holder,   wherein the first detection electrode is provided in a region of not more than 1.7% at a circumference of a circle passing through the first detection electrode around a rotation axis of the rotation mechanism, and   the controller is configured to estimate a film thickness of the plating film with rotation of the substrate achieved by the rotation mechanism.   
     
     
         4 . The plating apparatus according to  claim 1 , comprising:
 a paddle disposed between the resistor and the substrate; and   a paddle stirring mechanism configured to cause the paddle to reciprocate in a direction along the surface to be plated of the substrate,   wherein the first detection electrode is disposed in a region where the paddle reciprocates when the surface to be plated is viewed from the anode.   
     
     
         5 . The plating apparatus according to  claim 4 ,
 wherein the paddle stirring mechanism is configured to cause the paddle to reciprocate at a first cycle, and   the controller estimates the thickness of the plating film on the substrate by removing a vibration component having a frequency corresponding to the first cycle from the potential difference.   
     
     
         6 . The plating apparatus according to  claim 4 ,
 wherein the plating apparatus further comprises a rotation mechanism that rotates the substrate holder,   the paddle stirring mechanism is configured to cause the paddle to reciprocate at a first cycle,   the controller is configured to estimate the film thickness of the plating film with rotation of the substrate at a second cycle achieved by the rotation mechanism, and   the first cycle and the second cycle are adjusted such that the first cycle and the second cycle are not in a relationship of an integer multiple.   
     
     
         7 . The plating apparatus according to  claim 1 , wherein the substrate holder is configured to hold the substrate with a surface to be plated being oriented downward in the plating tank.