Alignment apparatus, control method thereof, exposure apparatus and method of manufacturing semiconductor device by exposure apparatus controlled by the same control method
AssigneeCanon Kabushiki Kaisha
InventorHiroshi Kurosawa
Life of this patent
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Abstract
X-axis interferometers which have a function of measuring the current position of a wafer stage in one direction simultaneously measure the current position, and at the same time, the initial value of one of the X-axis interferometers is set to the initial value of the other, thereby switching between the X-axis interferometers. Switching between the X-axis interferometers is performed while suppressing errors which may occur during stage driving.
Claims14
An alignment apparatus which drives to a target position a stage capable of moving at least in a two-dimensional direction, comprising:
- a plurality of position measurement devices which have a function of measuring a position of the stage in one direction simultaneously from different positions;
- a switching device which switches from one of said plurality of position measurement devices which simultaneously measure the position of the stage to another on the basis of at least one of position information and velocity information of the stage;
- and
- a setting device which sets an initial value of a second position measurement device after switching on the basis of the position of the stage measured by a first position measurement device before switching when said switching device switches between said position measurement devices,
- wherein said switching device switches between said position measurement devices during driving of the stage.
A method of controlling an alignment apparatus which drives to a target position a stage capable of moving at least in a two-dimensional direction, comprising:
- a measurement step of measuring a position of the stage in one direction simultaneously from different positions using a plurality of position measurement devices;
- a switching step of switching from one of the plurality of position measurement devices to another on the basis of at least one of position information and velocity information of the stage;
- and
- a setting step of setting an initial value of a second position measurement device after switching on the basis of the position measured by a first position measurement device before switching when in the switching step, switching between the position measurement devices is performed,
- wherein in the switching step, switching between the position measurement devices is performed during driving of the stage.
Dependencies are inferred from the claim text.