Substrate processing method, substrate processing apparatus and recording medium

A substrate processing apparatus configured to perform a liquid processing by supplying a processing liquid onto a substrate, the substrate processing apparatus comprising:

• a substrate holding unit configured to hold and rotate the substrate horizontally and equipped with a rotating mechanism configured to vary a rotation number of the substrate;
• a processing liquid nozzle configured to supply the processing liquid onto the substrate;
• a cleaning liquid nozzle configured to discharge a cleaning liquid slantly with respect to a surface of the substrate toward a downstream side in a rotational direction of the substrate being rotated;
• a gas nozzle configured to discharge a gas downwards;
• a nozzle moving mechanism configured to move the cleaning liquid nozzle and the gas nozzle between a central portion side of the substrate and a peripheral portion side thereof;
• and
• a control unit configured to output a control signal to conduct:
• performing a liquid processing by supplying the processing liquid from the processing liquid nozzle onto the substrate being rotated;
• supplying the cleaning liquid from the cleaning liquid nozzle onto the substrate being rotated after being subjected to the liquid processing and discharging the gas from the gas nozzle, when viewed from a liquid arrival position where the cleaning liquid reaches the substrate, toward a position adjacent to a central portion side of the substrate;
• moving the liquid arrival position from the central portion side of the substrate toward the peripheral portion side thereof by a nozzle moving mechanism in a state that a relative positional relationship between the liquid arrival position and a gas arrival position where the gas reaches the substrate is maintained;
• and
• varying the rotation number by the rotating mechanism such that, when a moving path of the liquid arrival position is divided at an intermediate position between a central portion of the substrate and a peripheral portion thereof and a region between the central portion and the intermediate position is defined as a first region whereas a region between the intermediate position and the peripheral portion is defined as a second region, the rotation number of the substrate in a period during which the liquid arrival position is moved in the second region becomes smaller than a maximum rotation number of the substrate in a period during which the liquid arrival position is moved in the first region.