摘要 |
PROBLEM TO BE SOLVED: To highly precisely measure the position of a fine movement stage on a coarse fine movement stage.SOLUTION: In measurement of positional information in the XY plane of a fine movement stage WFS held by a coarse movement stage WCS, an encoder system is used including a head which is placed facing a grating RG placed on a surface substantially parallel to the XY plane of the fine movement stage and irradiates the grating with a measurement beam. Then, the fine movement stage is driven individually or integrally with the coarse movement stage by a drive system, based on the positional information measured by the encoder system. In this case, the head of the encoder system is placed in proximity to the fine movement stage (the grating), which allows a highly precise measurement of the positional information of the fine movement stage by the encoder system. |