Multiple stage, stage assembly having independent reaction force transfer

Abstract

A stage assembly (10) for independently moving and positioning a first device (26A) and a second device (26A) in an operation area (25) is provided herein. The stage assembly (10) includes a stage base (12), a first stage (14), a first mover assembly (15), a second stage (16), and a second mover assembly (18). The first mover assembly (15) moves the first stage (14) and the first device (26A) into the operational area (25) and the second mover assembly (18) moves the second stage (16) and the second device (26B) into the operational area (25). The present stage assembly (10) reduces and minimizes the amount of reaction forces and disturbances that are transferred between the stages (14), (16). This improves the positioning performance of the stage assembly (10). Further, for an exposure apparatus (30), this allows for more accurate positioning of two semiconductor wafers (28) relative to a reticle (32) or some other reference.

Dependencies are inferred from the claim text.