Abstract: A method is presented for converting the sine/cosine signals from an optical encoder into a high-resolution position signal for use by a position control system while eliminating common noise and error sources. The improved noise performance resulting from the alias-free demodulation of encoder signals improves precision and reduces power consumption in precision motion control applications. The adaptive compensation of harmonic distortion eliminates errors related to offset, gain and quadrature of the encoder channels. The interpolator is able to process encoder signals at extremely high resolution without the speed limitation of prior art encoder interpolators.

Abstract: A mechanism for manipulation of a substrate over a substantially planar region has at least three, and up to six, degrees of freedom (DOF). The mechanism may be manufactured in various configurations, including triangular, and may use inherent symmetry to reduce the number of distinct components that must be manufactured. The mechanism may use parallelism to reduce the moving mass and thereby achieve higher levels of performance using less expensive motors while dissipating less power.

Abstract: 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.

Abstract: 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.