Patent ID: 6373159
Filing Date: 2002-04-16
Classification: F16C,H01L

Abstract:
A substrate rotating apparatus comprising:a rotor provided in a space communicating with a processing chamber, said rotor having a horizontal disk provided thereon, and said rotor being operable to rotate a substrate located thereon; magnetic bearings comprising electromagnets having yokes, said magnetic bearings being operable to support said rotor, said magnetic bearings including an axial magnetic bearing and a radial magnetic bearing, and said electromagnets being stator-side constituent members of said magnetic bearings; and a motor having a stator-side constituent member, said motor being operable to apply a rotational force to said rotor to rotate the substrate in the processing chamber, wherein said axial magnetic bearing comprises at least three divided axial magnetic bearings positioned so that imaginary lines connecting points where each of said at least three divided axial magnetic bearings are disposed form an approximately regular triangle or polygon, said electromagnets of said at least three divided axial magnetic bearings being disposed substantially above and below said horizontal disk of said rotor, wherein said stator-side constituent members of said magnetic bearings and said stator-side constituent member of said motor are located in a space defined to be outside of the space communicating with the processing chamber by a partition acting as a stator housing, said partition located between said rotor and said stator-side constituent members of said magnetic bearings and said stator-side constituent member of said motor, and wherein portions of said partition where said yokes of said electromagnets are located are fitted with a material that is electromagnetically equivalent to said yokes of said electromagnets as said stator-side constituent members of said magnetic bearings.