PURPOSE: To prevent metal powder generation due to abrasion in a treatment container in which a ring gear rotates a wafer-mount-base both around its axis and in a circular orbit, by a mechanism wherein strong permanent magnets are attached to the ring gear on its outer periphery and to the side face of the container so that repulsive force of the magnets floats the entire gear body.
CONSTITUTION: In a treatment container 1, a wafer-mount-base 2 is supported and rotated by a ring gear 3. The gear 3 is supported at the specified location by magnets 5.6 installed on the top of the container's support base 4 and the side face of the container, and by permanent magnets 7.8 installed on the top and bottom of the ring gear 3 so that the same polarity faces each other. The gear 3 is rotated by the drive gear 9 driven by a motor not shown. In this manner, the gear 3 is supported without contacting the container 1 and thus foreign suspended material is nearly completely eliminated. As a result, defect products are reduced, and maintenance and inspection become unnecessary for long periods of time.
HONMA KOUJI
KAMEYAMA KATSUNORI
