Substrate processing apparatus and substrate processing method

A substrate processing method of processing a combined substrate in which a first substrate having thereon a device layer and a second substrate are bonded to each other, the substrate processing method comprising:

• processing the first substrate in a state that a rear surface of the second substrate is held by a holder;
• etching a front surface of the first substrate opposite to a surface thereof where the device layer is provided by supplying a first processing liquid to the front surface of the first substrate through a first liquid supply line connected to a first liquid source;
• removing a metal contaminant on the rear surface of the second substrate by supplying a cleaning liquid to the rear surface of the second substrate through a cleaning liquid supply line connected to a cleaning liquid source;
• and
• after the etching of the front surface of the first substrate and after the removing of the metal contaminant on the rear surface of the second substrate, rinsing the front surface of the first substrate and the rear surface of the second substrate at a same time by supplying pure water to the front surface of the first substrate and the rear surface of the second substrate through a pure water supply line connected to a pure water source,
• wherein the cleaning liquid is an aqueous solution including hydrogen peroxide, and
• wherein the etching of the front surface by the first processing liquid and the removing of the metal contaminant by the cleaning liquid are performed at a same time.