摘要 |
A system for manipulating a planar substrate such as a semiconductor wafer is provided. The manipulator is typically used in conjunction with an XY stage to focus and planarize a wafer with respect to a tool. The manipulator employs redundant actuators of different types and a control system that uses low-bandwidth, high efficiency actuators to provide low frequency forces and high-bandwidth, but less efficient, actuators to provide all other forces. The manipulator provides support and manipulation of a substrate while minimizing errors due to thermal distortion.
|