| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide a method for separating an attracted object in an electro static chuck and an electrostatic chuck, in which an object attracted by an electrostatic force is surely separated in a short period of time. SOLUTION: A wafer S is attracted and fixed by applying a predetermined voltage to an electrostatic chuck body 1 from a power supply 2, on the basis of control by a controller 3. After the end of a process, application of attracting voltage is stopped, and a lift pin 5 is raised by manipulating an air cylinder 6 under the control of the controller 3. The voltage of a polarity inverted from that in attracting is then applied to the electrostatic chuck body 1 from the power supply 2 for a predetermined time period and whether or not the wafer S is separated is determined in the controller 3, on the basis of the detecting signal from a position detector 6a. When the wafer S is not separated, a voltage having the polarity inverted from the preceding one is then applied to the electrostatic chuck body 1 from the power supply 2 under the control of the controller 3. When the water S is separated or the voltage is applied for a given number of times for separation, the supply of voltage is completed.</p> |
