Real-time compensation of mechanical position error in pattern generation or imaging applications
AssigneeApplied Materials, Inc.
InventorsBruce B. Baxter, Benyamin Buller, Wenwei Qiao, Huei-Mei Kao
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Abstract
Improved systems, apparatus, and methods for detecting positions of moving stages and accurately compensating position error during operation (in “real time”) are provided. For some embodiments, rather than rely on two dimensional position measurements, measurements in at least three dimensions may be taken allowing compensation for pitch and roll and, therefore, more accurate position measurements. Further, by including a measurement of a beam column, compensation for movement of the beam may be performed.
Claims20
An apparatus for detecting a position of a movable stage, comprising:
- first interferometers for taking at least three measurements along at least three different axes, wherein at least one measurement along a first axis indicates a distance to a column, and at least two of the measurements along second and third axes indicate distances to different positions on the movable stage and wherein the first axis and the second and third axes are substantially parallel and coplanar, the first interferometers using a first beam splitter block;
- and
- logic for calculating a relative distance between the movable stage and the column based on the at least three measurements.
A method for compensating for a positional error of a movable stage, comprising:
- detecting a distance from a first interferometer to a column along a first axis;
- detecting distances from at least second and third independent interferometers to different locations on the movable stage along second and third axes, wherein the first axis and the second and third axes are substantially parallel and coplanar and the first, second, and third interferometers share a first beam splitter block;
- calculating a relative distance between at least one of the locations on the movable stage and the column or a parameter related to the relative distance between the different locations on the movable stage based on the detected distances;
- and
- adjusting the position of the movable stage or a beam of the column based on the calculation.
Dependencies are inferred from the claim text.