Plating apparatus
Provided is a plating apparatus capable of improving uniformity of a plating film formed on a substrate. The plating apparatus includes a plating tank, a substrate holder that holds a substrate, and an anode disposed in the plating tank to oppose the substrate held by the substrate holder. The plating apparatus also includes a conduit having a first portion including an opening end disposed in a region between the substrate held by the substrate holder and the anode, and a second portion apart from the region between the substrate held by the substrate holder and the anode, the conduit having at least a part filled with a plating solution, and a potential sensor that is disposed in the second portion of the conduit and that is configured to measure a potential of the plating solution.
1 . A plating apparatus comprising:
a plating tank;
a substrate holder that holds a substrate;
an anode disposed in the plating tank to oppose the substrate held by the substrate holder;
a conduit having a first portion including an opening end disposed in a region between the substrate held by the substrate holder and the anode, and a second portion apart from the region between the substrate held by the substrate holder and the anode, the conduit having at least a part filled with a plating solution;
a first detection electrode that is a potential sensor disposed in the second portion of the conduit, and configured to measure a potential of the plating solution;
a second detection electrode that is a potential sensor for reference, the second detection electrode disposed at a second position and configured to measure potential of the plating solution outside of a region between the substrate and the anode as compared to the opening end in the plating tank; and
a control module 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.
2 . The plating apparatus according to claim 1 , wherein the opening end of the conduit faces a surface to be plated of the substrate held by the substrate holder.
3 . The plating apparatus according to claim 1 , further comprising:
a resistor disposed between the anode and the substrate held by the substrate holder, wherein the opening end of the conduit is disposed between the resistor and the substrate.
4 . The plating apparatus according to claim 1 , wherein the second portion of the conduit extends outside the plating tank.
5 . The plating apparatus according to claim 1 , further comprising:
a paddle disposed between the substrate held by the substrate holder and the anode, and
a paddle stirring mechanism that moves the paddle to stir the plating solution, wherein the first portion of the conduit is disposed on an outer peripheral side of the paddle.
6 . The plating apparatus according to claim 1 , further comprising:
the control module configured to estimate a distribution of a plating current in the substrate during a plating process based on the potential difference between the first detection electrode and the second detection electrode.
7 . The plating apparatus according to claim 6 , wherein the control module is configured to estimate a film thickness distribution of the plating film in the substrate based on the estimated distribution of the plating current in the substrate.
8 . The plating apparatus according to claim 1 , further comprising:
a control module that adjusts plating conditions during a plating process based on the potential difference between the first detection electrode and the second detection electrode.
9 . The plating apparatus according to claim 1 , further comprising:
a second conduit having a third portion including an opening end disposed in a region between the substrate holder and the anode in the plating tank, and a fourth portion apart from the region between the substrate holder and the anode, the second conduit having at least a part filled with the plating solution, and
an auxiliary anode disposed in the fourth portion of the second conduit.
10 . The plating apparatus according to claim 1 , further comprising:
a rotation mechanism that rotates the substrate holder.
11 . 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.
12 . 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 laterally in the plating tank.