Back to results
US 6,822,407 B2Granted
Multiple degree of freedom substrate manipulator
AssigneeActive Precision, Inc.
InventorBradley L. Hunter
Life of this patent
Estimating the term…
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.
Claims2
An actuator that manipulates an object, comprising:
- a housing;
- at least three tangentially acting voice coil motors disposed to move the object relative to the housing in a yaw direction;
- at least three radially acting electromagnet actuators maintaining a substantially constant gap between the object and a housing independent of motion in the yaw direction;
- and
- a control system that supplies the object with large low-frequency forces in a plane of the object using the radially acting electromagnet actuators, and supplies low amplitude high-frequency forces in the plane of the object and provides forces for motion in the yaw direction using the tangential voice coil motors.
2 more elements
Dependencies are inferred from the claim text.