| 摘要 |
<p>PURPOSE:To provide an electrostatic chuck wherein whether a workpiece is properly attracted or not can be externally judged by detecting the status of attraction. CONSTITUTION:The electrostatic shuck consists of a dielectric 1 and an electrode 2. In addition part of its attracting surface where a workpiece 3 is to be attracted is composed of a piezoelectric element 4. The electrostatic chuck also includes a detecting circuit 7 that measures the output of the piezoelectric element 4 on which part of attractive force is exerted. This provides the chuck with improved safety and reliability.</p> |
