Substrate processing apparatus and substrate processing method

A substrate processing method, comprising the steps of:

• arranging a blocking member including a plate member spaced away from a substrate surface while facing the substrate surface to define a clearance space with the substrate surface,
• the blocking member including:
• a rotary spindle which is hollow and supports the plate-like member, and an inner shaft inserted in said hollow rotary spindle;
• a processing liquid discharge port which is disposed at an end of the inner shaft, and receives and discharges water or a liquid whose principal component is water as a processing liquid to a central part of the substrate surface through the clearance space, the substrate being held in a substantially horizontal posture;
• and
• a solvent discharge port which discharges a low surface-tension solvent having a lower surface tension than the processing liquid to the central part of the substrate surface through the clearance space, the solvent discharge port being disposed at said end of the inner shaft;
• discharging the processing liquid from the processing liquid discharge port to the substrate surface while the substrate is rotated to perform predetermined wet processing to the substrate surface;
• discharging the low surface-tension solvent from the solvent discharge port to the substrate surface wet with the processing liquid while the substrate is rotated to replace the processing liquid adhering to the substrate surface with the low surface-tension solvent;
• and
• removing the low surface-tension solvent from the substrate surface after the replacing step to dry the substrate surface, wherein
• the blocking-member arranging step further includes the steps of:
• providing a gas discharge port disposed at the end of the inner shaft near the solvent discharge port and the processing liquid discharge port which receives and discharges an inert gas to the central part of the substrate surface;
• and
• an outer gas discharge port which is an aperture defined between an inner wall surface of the rotary spindle and an outer wall surface of the inner shaft, and which receives and discharges an inert gas to the surface of the substrate, the outer gas discharge port being located radially outward of and surrounding the processing liquid discharge port, the solvent discharge port and the gas discharge port,
• wherein the end of the inner shaft, including the processing liquid discharge port, the solvent discharge port and the gas discharge port is recessed upward from a plane including a lower surface of the plate member of the blocking member, within the outer gas discharge port, thereby decreasing a flow velocity of the gas discharge port;
• and
• the inert gas is supplied from the gas discharge port and the outer gas discharge port, in the wet processing step and the replacing step, into said clearance space defined between the blocking member arranged in the blocking-member arranging step and the substrate surface.