Substrate processing apparatus, substrate processing method and computer-readable storage medium recording therein substrate processing program

A computer-readable storage medium having stored thereon computer-executable instructions that, in response to execution, cause a substrate processing apparatus to perform a substrate processing program of processing a substrate with a processing liquid and drying the substrate,

• wherein the substrate processing apparatus includes:
• a substrate rotating device configured to rotate the substrate;
• a processing liquid discharging unit configured to discharge the processing liquid toward the substrate;
• a substitution liquid discharging unit configured to discharge a substitution liquid, which is substituted with the processing liquid on the substrate, toward the substrate;
• and
• an inert gas discharging unit configured to discharge an inert gas toward the substrate, the inert gas discharging unit including a first inert gas discharge nozzle provided vertically downward and a second inert gas discharge nozzle provided to be inclined downward, and
• wherein the substrate processing program includes:
• discharging the processing liquid toward the substrate from the processing liquid discharging unit while rotating the substrate by the substrate rotating device, and then;
• discharging the substitution liquid from the substitution liquid discharge unit toward the substrate from the substitution liquid discharging unit while moving the substitution liquid discharging unit relatively with respect to the substrate to form a liquid film of the substitution liquid on the substrate;
• discharging a first inert gas, from the first inert gas discharge nozzle, vertically downward from above a central portion of the substrate toward a central portion of the liquid film of the substitution liquid formed on the substrate while horizontally moving the substitution liquid discharge unit along the substrate toward a peripheral portion thereof and without moving the first inert gas discharge nozzle to form an interface where the liquid film of the substitution liquid is thicker at a peripheral portion side of the substrate than at a central portion side thereof and to increase an area confined by the interface uniformly from the central portion of the substrate toward a peripheral portion thereof, and then
• pushing the interface from the central portion of the substrate toward the peripheral portion thereof by discharging a second inert gas, from the second inert gas discharge nozzle, toward the substrate in an inclined direction from above the substrate toward the peripheral portion of the substrate while moving the second inert gas discharge nozzle relatively with respect to the substrate in a direction different from a direction in which the substitution liquid discharging unit is moved.