Film forming apparatus for forming metal film and film forming method for forming metal film

A film forming apparatus for forming a metal film, comprising:

• an anode;
• a solid electrolyte membrane disposed between the anode and a substrate that serves as a cathode;
• a power supply configured to apply a current between the anode and the substrate;
• a mount base on which the substrate is placed;
• and
• a housing including a storing chamber that stores an electrolytic solution together with the anode and having the solid electrolyte membrane attached thereto so as to seal the storing chamber;
• wherein the current is applied in a state where the solid electrolyte membrane is pressed against the substrate with a fluid pressure of the electrolytic solution in the storing chamber to form a metal film from metal ions contained in the electrolytic solution on a surface of the substrate, and
• the mount base includes a liquid discharge portion port configured to discharge the electrolytic solution having passed through the solid electrolyte membrane from a position facing an end face of a side wall of the housing;
• wherein a suction pump that sucks the electrolytic solution from the liquid discharge port is coupled to the liquid discharge port;
• and
• wherein the power supply is configured to apply a current between the anode and the substrate such that a current applied between the anode and the substrate is kept constant during formation of the metal film, the film forming apparatus for forming a metal film further comprising:
• a voltmeter configured to measure a voltage across the anode and the substrate;
• and
• a control device configured to control starting and stopping of the suction pump;
• wherein during the formation of the metal film, the control device starts the suction pump when a voltage measured by the voltmeter is equal to or higher than a predetermined voltage value, and stops the suction pump after a lapse of a time set in advance after the suction pump is started.