| 摘要 |
PURPOSE: To drive a linear motor without providing a particular phase switching sensor in an aligner using the linear motor as a driving device of a stage. CONSTITUTION: An X stage 10X on the wafer side is driven in the X direction for a wafer base 11 via a linear motor composed of a stator 12A and needles 12B. A thrust FWX obtained from a position deflectionΔXwi , etc., between X coordinates Xw and target coordinates Xwi of an X stage 10X on the wafer side measured by a wafer interferometer 14X is supplied to multiplying means 27A to 27C. Functions cosθto co(θ-1π/2) corresponding to the phases of the stator 12A and the needles 12B are abtained from the X coordinates Xw via a fraction detecting means 28 and a phase converting means 29A to 29C, and supplied to the multiplying means 27A to 27C. An excitation current is supplied to an armature coil of the linear motor based on the outputs of the multiplying means 27A to 27C. |
