摘要:
The positioning appts. includes an substrate table (1), a subsystem for processing an object on the table, a drive unit (21) displacing the table, and a system (39) measuring the position of table w.r.t. the subsystem. The drive unit has a stationary part fastened to the positioning appts. machine frame co-operating with the measuring system's stationary and movable parts fastened to the table. The measuring system stationary part is fastened to the positioning appts. reference frame dynamically isolated from the machine frame.
摘要:
The positioning mechanism has a force actuator system controlled by an electric controller, and which exerts a compensation force on the frame (45) during operation. The force has a mechanical moment about a reference point of the frame. This moment has a value equal to a value of a mechanical moment of a force of gravity acting on the object table (5) about the reference point, and a direction opposed to a direction of the mechanical moment of the force of gravity.