Alignment apparatus
AssigneeCanon Kabushiki Kaisha
InventorHiroyuki Sekiguchi
Life of this patent
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Abstract
An apparatus for moving a stage, supported by a base, to a target position. The apparatus includes a motor for driving the stage in X and Y directions, a laser interferometer for measuring a current position of the stage in the X and Y directions and a controller for generating a control signal for controlling the motor to move the stage to the target position in the X and Y directions on the basis of the target position and for dynamically setting a transfer function associated with generation of the control signal in correspondence with the current measured position. The controller sets the transfer function so that a gain decreases as the stage moves toward a peripheral portion of the base.
Claims7
An apparatus for moving a stage, supported by a base, to a target position, said apparatus comprising:
- a motor for driving the stage in X and Y directions;
- a laser interferometer for measuring a current position of the stage in the X and Y directions;
- and
- a controller for generating a control signal for controlling said motor to move the stage to the target position in the X and Y directions on the basis of the target position, and for dynamically setting a transfer function associated with generation of the control signal in correspondence with the current measured position,
- wherein said controller sets the transfer function so that a gain decreases as the stage moves toward a peripheral portion of the base.
Dependencies are inferred from the claim text.