Substrate drying apparatus, substrate drying method and control program

A substrate drying method of supplying a substrate rotating in a horizontal plane with a rinse agent flow and a drying gas flow while the rinse agent flow and the drying gas flow are moved from the center side toward an outer periphery side of the rotating substrate, the drying gas flow being able to contain IPA, comprising the steps of:

• a center area drying step of drying a center area of the substrate, the center area being a range where a rotation center of the substrate exists in a collision range of the drying gas flow with the substrate;
• and
• an outer periphery area drying step of drying an outer periphery area existing outside of the center area of the substrate,
• wherein an IPA concentration of the IPA contained in the drying gas flow is maintained at less than 2 mol % during the center area drying step, and the IPA concentration is adjusted higher in the outer periphery area drying step than in the center area drying step.

A substrate drying method of supplying a substrate rotating in a horizontal plane with a rinse agent flow and a drying gas flow while the rinse agent flow and the drying gas flow are moved from the center side toward an outer periphery side of the rotating substrate, the drying gas flow being able to contain IPA, comprising the steps of:

• a center area drying step of drying a center area of the substrate, the center area being a range where a rotation center of the substrate exists in a collision range of the drying gas flow with the substrate;
• and
• an outer periphery area drying step of drying an outer periphery area existing outside of the center area of the substrate,
• wherein an IPA concentration of the IPA contained in the drying gas flow is maintained at a concentration substantially preventing a Marangoni effect during the center area drying step, and the IPA concentration is adjusted to a concentration generating a Marangoni effect during the outer periphery drying step.