摘要 |
PURPOSE:To improve controlling accuracy of an incident ion energy by setting a frequency of a high frequency power source to 20MHz or higher, and forming an output waveform of a low frequency power source to cancel a surface potential change due to storage electric amount on a substrate each other out. CONSTITUTION:When a processing chamber 1 is held at a set pressure of 10-0.01Torr and a high frequency voltage is applied by a high frequency power source 5 to an electrode 3, a plasma is generated between the electrodes 2 and 3. A high frequency current of the power source 5 is fed through the electrode 3, the plasma and the electrode 2 directly to an earth but does not pass a low pass filter 11. A signal of a low frequency signal oscillator 8 is input to a low frequency power amplifier 9, amplified, matched by a matching transformer 10, and applied through the filter 11 to the electrode 2. The frequency of the high frequency power source is set to 20MHz or higher, and a surface potential change due to a storage electric amount on a substrate is canceled by the output waveform of a low frequency power source. Thus, controlling accuracy of a substrate incident ion energy is improved to improve the processing capacity due to an increase in an etching velocity.
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