| 摘要 |
<p>PURPOSE:To easily and securely separate from an electrostatic chuck a wafer, which has already been processed, without damaging the wafer by, upon interrupting the application of a voltage applied to the electrostatic chuck of a semiconductor manufacturing apparatus, turning off the application while alternating the polarity of the voltage. CONSTITUTION:Upon removing electric charges induced in an insulator 11 of an electrostatic chuck 10, an applied voltage to the electrostatic chuck is changed to -V1 which has a peak voltage less than the voltage V0 upon attraction of the chuck and has a reverse polarity, then changed to +V2 less than +V0, and to -V3 less than -V1. This is repeated in succession to bring the voltage to 0 volt. It is assumed that +100V is applied to a point A in the figure from a power supply 12 and -1000V to a point B from another power supply 14. The points A, B are branch points between lines connecting the power supplies 12, 14 to the electrodes 13, 13 and to the electrodes 15, 5. Upon interrupting the voltage, the voltage from the power supply 12 to the point A is decreased in succession by -1/2 time at each 1sec for example to 0V, like a voltage series: -500V, 250V, -125V, and 62.5V.... Electric charges induced in the electrostatic chuck are induced in the electrostatic chuck are surely reduced, to assure the separation of a wafer 16 from the electrostatic chuck by means of the operation of pins.</p> |
