Method for holding substrates

摘要

A method of holding utilizing a fixture with five discrete vacuum elements provides support at four peripheral points on a substrate and at the substrate center. Two peripheral vacuum elements are fixed in position on a rigid frame. The remaining peripheral elements and the center element are fixed to a gimbal disc. This gimbal disc is mounted on the frame in such a way that it has three degrees of rotational movement relative to the frame. Downward pressure of a substrate resting on the two fixed elements, brings all three gimbal disc mounted supports into contact with the substrate, without allowing or causing deflection of the substrate. The mounting is locked, and vacuum is applied to all the elements to secure the substrate in place for the planarizing operation.