Substrate cleaning method and substrate cleaning apparatus

A substrate cleaning apparatus for cleaning and drying a substrate, comprising:

• a substrate holder configured to hold the substrate substantially horizontally;
• a rotation drive mechanism configured to rotate the substrate held by the substrate holder about an axis perpendicular to the substrate;
• a cleaning-liquid nozzle configured to discharge a cleaning liquid to a surface of the substrate while the substrate is rotated;
• a cleaning-liquid-nozzle drive mechanism configured to move the cleaning-liquid nozzle;
• a gas nozzle configured to discharge a gas to the surface of the substrate while the substrate is rotated;
• a gas-nozzle drive mechanism configured to move the gas nozzle;
• and
• a control part configured to control the substrate holder, the rotation drive mechanism, the cleaning-liquid nozzle, the cleaning-liquid-nozzle drive mechanism, the gas nozzle and the gas-nozzle drive mechanism,
• wherein the control part is configured to control the substrate holder and the rotation drive mechanism to perform a step in which the substrate is held substantially horizontally and is rotated about the axis perpendicular to the substrate, to control the cleaning-liquid nozzle to perform a step in which the cleaning liquid is discharged from the cleaning-liquid nozzle to a central part of the substrate while the substrate is rotated, to control the cleaning-liquid nozzle drive mechanism to perform a step in which the cleaning-liquid nozzle is moved such that a to-be-discharged position of the cleaning liquid on the substrate is moved by a predetermined distance from the central part of the substrate toward a periphery of the substrate, to control the gas nozzle to perform a step in which the gas is discharged from the gas nozzle to the central part of the substrate while the substrate is rotated during a predetermined time period, so as to form a dried area of the cleaning liquid in the central part of the substrate, under a condition wherein the to-be-discharged position of the cleaning liquid on the substrate is maintained at the predetermined distance from the central part of the substrate, and to control the cleaning-liquid-nozzle drive mechanism and the gas-nozzle drive mechanism to perform a step in which the cleaning-liquid nozzle is further moved such that the to-be-discharged position of the cleaning liquid on the substrate is further continuously moved toward the periphery of the substrate and the gas nozzle is also moved such that a to-be-discharged position of the gas on the substrate is maintained at the predetermined distance from the to-be-discharged position of the cleaning liquid on the substrate, after the dried area has been formed in the central part of the substrate.