Patent ID: 8006636

Claim:
A substrate treatment apparatus comprising a holding means for rotatably holding a substrate to be treated; a rotation means for rotationally driving said holding means; a treatment solution supply nozzle for supplying a treatment solution onto the substrate to be treated held on said holding means; a treatment container with an upper surface open for housing said holding means; and an exhaust means for exhausting air from a bottom of said treatment container, further comprising: a multiblade centrifugal fan provided on an inner periphery side of said treatment container for flowing airflow on a front surface side of the substrate to be treated to said exhaust means side; and a control means connected to said rotation means and a drive unit for said multiblade centrifugal fan for controlling a number of rotations of said multiblade centrifugal fan corresponding to a number of rotations of the substrate to be treated by said rotation means, wherein a control signal from said control means is transmitted to said multiblade centrifugal fan so that turbulent airflow flowing in a circumferential direction on the front surface of the substrate to be treated generated due to the rotation of the substrate to be treated is corrected to laminar airflow flowing in a radial direction, and wherein said multiblade centrifugal fan comprises an annular electromagnetic coil disposed on the inner periphery side of said treatment container, a fan main body having many radial fins, an annular magnet attached to an outer periphery of said fan main body and facing an inner side of said annular electromagnetic coil, and a support body for rotatably supporting said fan main body on the inner periphery side of said treatment container via a thrust bearing, and said multiblade centrifugal fan is mounted on a mounting portion provided protruding on an inner peripheral surface of said treatment container.