Substrate processing apparatus and substrate processing method

A substrate processing apparatus, comprising:

• a processing tank configured to store a chemical solution to process a substrate by immersion of the substrate in the chemical solution;
• a holder configured to hold the substrate while immersed in the chemical solution;
• a lid disposed on processing tank for opening and closing an upper end of the processing tank, the lid having a first portion hinged to a first side of the processing tank and second portion hinged to a second side of the processing tank opposite to the first side;
• a first bubble dispensing pipe, the first bubble dispensing pipe being configured to dispense a gas into the processing tank from the lid;
• an outer overflow tank surrounding the processing tank at an upper end of the processing tank;
• and
• a second bubble dispensing pipe with a gas outlet port on a bottom surface of the outer overflow tank,
• a third bubble dispensing pipe with a gas outlet port at a bottom surface of the processing tank and a recirculating path connected between the bottom surface of the outer overflow tank and the bottom surface of the processing tank,
• wherein
• a bottom surface of each of the first and second portions directly contacts the chemical solution stored in the processing tank when the lid is closed,
• the bottom surface of the first portion angles upward from the first side of the processing tank toward a middle of the processing tank, and
• the bottom surface of the second portion angles upward from the second side of the processing tank toward the middle of the processing tank;
• wherein the bottom surfaces of each of the first and second portions of the lid have gas outlets therein connected to the first bubble dispensing pipe.