| 摘要 |
A system for precisely positioning and moving a platform relative to a support structure is disclosed herein. The platform is particularly suitable for carrying wafers. Charged particle optics can be attached to the support structure. The platform positioning system comprises a stage, comprising a base, a platform and stage actuators, the stage actuators being coupled to the platform and the platform being coupled to the base; a frame attached to the base; a support structure mechanically coupled to the frame; stage sensors attached to the support structure, for sensing the position of the platform relative to the support structure; and a current control system coupled to the stage sensors and the stage actuators. The current control system may include a predictor for generating an ouptut signal anticipating the actual position of the platform relative to the support structure in real time. |
