| 摘要 |
<p>PURPOSE:To perform precision etching while the temperature of a wafer is controlled by using a radio frequency voltage with a relatively low frequency by a method wherein a DC voltage is applied to one of a pair of planar electrodes through a low-pass filter and the radio frequency voltage with a frequency less than 1MHz is applied to a pair of the planar electrodes through capacitors. CONSTITUTION:A radio frequency voltage with a frequency less than 1MHz applied to a pair of planar electrodes 25 from an RF source 6 through capacitors 26 is further applied to a wafer 3 and a support table 11 whose temperature is controlled by water cooling or the like from a pair of the planar electrodes 25 through the insulating layer 20 of an electrostatic chuck. With this method, the impedance between the planar electrode and a plasma through an insulating layer 9 closer to the wafer is smaller than the impedance through the other route. Therefore, the plasma is generated above the wafer 3 with satisfactory balance, the distribution of etching is improved, an abnormal discharge in a gap 24 can be avoided and excel 3 ent etching can be performed. Further, as the electrostatic chuck having a pair of the planar electrodes whose applied radio frequency voltage is prevented from flowing into a DC source 22 by low-pass filters 21 is employed, the sttraction force is not degraded and a stable cooling effect can be obtained.</p> |
