Patent ID: 8109282

Claim:
A substrate processing apparatus, comprising: a substrate holder which holds a substrate in a substantially horizontal posture; a substrate rotating unit which rotates the substrate held by the substrate holder about a predetermined rotation axis; a blocking member which includes a plate-like member arranged away from the substrate surface while facing the substrate surface to define a clearance space with the substrate surface, a rotary spindle which is hollow inside and supports the plate-like member and an inner shaft which is inserted in a hollow part of the rotary spindle; a processing liquid supplier which discharges a processing liquid from a processing liquid discharge port disposed to an end of the inner shaft to a central part of the substrate surface through the clearance space; a solvent supplier which discharges a low surface-tension solvent having a lower surface tension than the processing liquid from a solvent discharge port disposed to the end of the inner shaft to the central part of the substrate surface through the clearance space, the solvent discharge port having a bore diameter smaller than that of the processing liquid discharge port; and a gas supplier which includes a first gas discharge port and a second gas discharge port, the first gas discharge port being disposed to the end of the inner shaft near the solvent discharge port and the processing liquid discharge port and discharging an inert gas to the central part of the substrate surface though the clearance space, and the second gas discharge port being an aperture defined between an inner wall surface of the rotary spindle and an outer wall surface of the inner shaft and discharging an inert gas from the blocking member side to the clearance space so that the inert gas from the second gas discharge port surrounds the solvent discharge port, the processing liquid discharge port and the first gas discharge port, wherein an aperture area of the second gas discharge port is larger than an aperture area of the first gas discharge port, and the end of the inner shaft is retracted upward from a plane including a lower surface of the plate-like member and thereby a flow velocity of the gas from the first gas discharge port is decreased.