Patent ID: 7958898

Claim:
A substrate processing apparatus, comprising: a substrate holding unit which generally horizontally holds a substrate and rotates the substrate about a generally vertical rotation axis; a process liquid supplying unit for supplying a process liquid to the substrate held by the substrate holding unit; a first guide portion provided surrounding the substrate holding unit, having an upper edge portion extending toward the rotation axis, for receiving and guiding the process liquid scattered from the substrate rotated by the substrate holding unit to cause the process liquid to flow down; a second guide portion provided surrounding the substrate holding unit outside the first guide portion, having an upper edge portion extending toward the rotation axis and vertically overlapping with the upper edge portion of the first guide portion, for receiving and guiding the process liquid scattered from the substrate rotated by the substrate holding unit to cause the process liquid to flow down; a third guide portion provided surrounding the substrate holding unit outside the second guide portion, having an upper edge portion extending toward the rotation axis and vertically overlapping with the upper edge portion of the second guide portion, for receiving and guiding the process liquid scattered from the substrate rotated by the substrate holding unit to cause the process liquid to flow down; a first recovery channel, provided outside the first guide portion and formed integrally as a unit with the first guide portion, for recovering the process liquid guided to flow down by the second guide portion; a second recovery channel, provided outside the first recovery channel and formed integrally as a unit with the first guide portion, for recovering the process liquid guided to flow down by the third guide portion; a driving mechanism for moving up and down the first guide portion, the second guide portion, and third guide portion independently of each other, for selectively disposing said first, second and third guide portions in respective vertical positions so that only one of said first, second and third guide portions receives said scattered process liquid and guides said process liquid to flow down; a hollow cylindrical inner wall provided inside the first guide portion and formed integrally as a unit with the first guide portion and thereby moving up and down with said first guide portion, and surrounding the rotation axis; and a hollow cylindrical cover flange, having a diameter larger than a diameter of the inner wall, fixed under the substrate holding unit and surrounding the rotation axis, wherein the inner wall and the hollow cylindrical cover flange are arranged such that the inner wall and the hollow cylindrical cover flange have respective portions that overlap with each other when seen horizontally, irrespective of a vertical position of the first guide portion, thereby blocking process liquid guided by said first guide portion from reaching the rotation axis.