Positioning apparatus having the interferometer and accelerometer positioned such that there signals are in phase

A positioning apparatus, comprising:

• a stationary surface;
• a movable stage, disposed on said stationary surface, movable in at least one direction on said stationary surface, wherein acceleration of said movable stage vibrates said stationary surface;
• a stage position measuring device, disposed on said stationary surface, measuring the position of said movable stage and outputting a position signal representative thereof and of the vibration of said stationary surface occurring in response to the acceleration of said movable stage;
• an accelerometer, disposed on said stationary surface, measuring the acceleration of said stationary surface and outputting an acceleration signal representative thereof;
• a console setting a target position of said movable stage and outputting a target position signal representative thereof;
• means for driving said movable stage;
• a controller, attached to said console, said stage position measuring device, said accelerometer, and said driving means, said controller receiving the target position signal from said console, the position signal from said stage position measuring device, and the acceleration signal from said accelerometer, said controller outputting a driving signal to said driving means instructing said driving means to drive said movable stage to the set target position, and instructing said movable stage to move in the same manner as said stationary surface, in the event said stationary surface vibrates in response to acceleration of said movable stage, in accordance with the position signal and the acceleration signal,
• wherein said stage position measuring device and said accelerometer are positioned such that the position signal is in phase with the acceleration signal in the event the vibration of said stationary surface has a translational component and a rotational component simultaneously.