Positioning device having dynamically isolated frame, and lithographic device provided with such a positioning device

Abstract

A positioning device includes an object table, a sub-system for processing an object to be placed on the object table, a drive unit for displacing the object table relative to the sub-system, and a measuring system for measuring a position of the object table relative to the sub-system. The drive unit includes a stationary part which is fastened to a first frame of the positioning device, while the measuring system includes a stationary part and a movable part which is fastened to the object table for cooperation with the stationary part of the measuring system. The stationary part of the measuring system is fastened to a second frame of the positioning device which is dynamically isolated from the first frame.

Description

[0001]This is a Division of application Ser. No. 09 / 449,763 filed Nov. 26, 1999, which in turn is a Continuation of application Ser. No. 09 / 192,153 filed Nov. 12, 1998 (now U.S. Pat. No. 6,246,202), which is a Continuation of application Ser. No. 08 / 416,558 filed Apr. 4, 1995 (now U.S. Pat. No. 5,874,820). Said application Ser. No. 09 / 449,763 also is a Continuation-In-Part of application Ser. No. 09 / 127,288 filed Jul. 31, 1998 (now U.S. Pat. No. 6,049,186), which is a Continuation of application Ser. No. 08 / 627,824 filed Apr. 2, 1996 (now U.S. Pat. No. 5,942,871), which is a Continuation of application Ser. No. 08 / 221,375 filed Apr. 1, 1994 (now U.S. Pat. No. 5,528,118). The entire disclosures of the above-identified prior applications are hereby-incorporated by reference herein in their entireties.BACKGROUND OF THE INVENTION[0002]1. Field of the Invention[0003]This invention relates to precision motion stages and more specifically to a stage suitable for use in a photolithography m...

AI Technical Summary

Benefits of technology

[0008]A precision motion stage mechanism includes the stage itself which moves in the X-Y plane on a flat base. The stage is laterally surrounded by a “window frame” guide structure which includes four members attached at or near their corners to form a rectangular structure. The attachments are flexures which are a special type of hinge allowing movement to permit slight distortion of the rectangle. In one version, these flexures are thin stainless steel strips attached in an “X” configuration, allowing the desired degree of hinge movement between any two adjacent connected window frame members.

[0014]An additional aspect in accordance with the invention is that the reaction force of the stage and window frame drive motors is not transmitted to the support frame of the photolithography apparatus projection lens but is transmitted independently directly to the earth's surface by an independent supporting structure. Thus, the reaction forces caused by movement of the stage do not induce undesirable movement in the projection lens or other elements of the photolithography machine.

[0016]Advantageously, the reaction forces from operation of the four motor coils for moving both the stage and its window frame are transmitted through the center of gravity of the stage, thereby desirably reducing unwanted moments of force (i.e., torque). The controller controlling the power to the four drive motor coils takes into consideration the relative position of the stage and the frame and proportions the driving force accordingly by a differential drive technique.

Problems solved by technology

Additionally, many prior art stages do not drive the stage through its center of gravity which undesirably induces a twisting motion in the stage, reducing the frequency response of the stage.

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