Plating method and plating apparatus

An apparatus for plating a substrate, comprising:

• a substrate holder including a first holding member and a second holding member which has an opening, the substrate holder being configured to hold a substrate by supporting one surface of the substrate with the first holding member while placing the second holding member in contact with other surface of the substrate, with the other surface of the substrate exposed through the opening of the second holding member, the second holding member having a first protruding portion configured to seal a gap between the first holding member and the second holding member and a second protruding portion configured to seal a peripheral portion of the substrate when the substrate is held by the substrate holder to form an internal space in the substrate holder by the first holding member, the second holding member, and the substrate, the substrate holder having an internal passage communicating with the internal space;
• a suction coupling coupled to a suction line extending from a vacuum source and detachably mounted to the substrate holder so as to communicate with the internal passage;
• a pressure sensor configured to check whether pressure in the internal space reaches a predetermined vacuum pressure within a certain period of time when producing a vacuum in the internal space through the suction line;
• and
• a pressure change detection section configured to detect a change in the pressure in the internal space after the vacuum is produced in the internal space and the internal space is closed off;
• wherein the apparatus is operable to perform a first-stage leakage test of the substrate holder for inspecting the first protruding portion and the second protruding portion by producing a vacuum in the internal space and checking whether pressure in the internal space reaches a predetermined vacuum pressure within a certain period of time, then perform a second-stage leakage test of the substrate holder, which has passed the first-stage leakage test, for further inspecting the first protruding portion and the second protruding portion by closing off the internal space after producing the vacuum therein and checking whether a change in the pressure in the internal space reaches a predetermined value within a certain period of time, and then plate the substrate in a plating bath with use of the substrate holder that has passed the second-stage leakage test.