Patent ID: 8857449

Claim:
A substrate processing apparatus which dries a surface of a substrate which is wet with a liquid, the apparatus comprising: a proximity member made of quartz, which includes an opposed surface facing the surface of the substrate and which is structured to move freely and relatively in a predetermined moving direction relative to the substrate in a condition that the opposed surface is positioned away from the surface of the substrate and that a gap space between the opposed surface and the surface of the substrate is filled up with the liquid to form a liquid-tight layer; wherein the proximity member has the shape of a right prism and is substantially trapezoidal in its vertical cross-section, including an extending surface which is connected with an upstream side which is one of sides defining the opposed surface and which is located on the upstream side of the proximity member in the moving direction, and which extends inclined from the upstream side in a direction away from the substrate surface overlooking the upstream side in the moving direction; and wherein the proximity member forms an interface of the liquid-tight layer at the upstream side, contained between the upstream side and the surface of the substrate; a driver which relatively moves the proximity member in the moving direction relative to the substrate; a solvent gas supplier which supplies a solvent gas which is one of IPA, ethyl alcohol and methyl alcohol toward an upstream-side end portion of the liquid-tight layer in the moving direction, the solvent gas containing a solvent component which dissolves in the liquid to reduce a surface tension; wherein the solvent gas supplier includes a gas nozzle which is disposed in a space above the upstream-side end portion of the proximity member, and which discharges the solvent gas from above so as to supply the solvent gas toward the upstream-side end portion of the proximity member, the solvent gas being guided at least partly along the extending surface of the proximity member; and a liquid layer forming section which forms a liquid puddle layer on an entire downstream-side surface of the substrate relative to the upstream-side end portion of the liquid-tight layer in the moving direction; at the upstream-side end portion of the proximity member, the opposed surface and the extending surface are at an acute angle, so as to form a meniscus between the vicinity of the upstream side of the proximity member and the substrate, thereby maintaining a gas-liquid-solid interface on the surface of the substrate in the vicinity of the upstream side; and a liquid supplier which, while the proximity member relatively moves, supplies the liquid toward the downstream-side surface of the substrate relative to the upstream-side end portion of the liquid-tight layer in the moving direction, thereby maintaining the puddle-like liquid layer on the entire downstream-side surface of the substrate relative to the upstream-side end portion of the liquid-tight layer.