| 摘要 |
PURPOSE:To enable to perform an optimum processing on the titled device by a method wherein one end of a parallel-plate electrode is grounded through a variable reactance element, a high frequency power source is connected to the other end of the parallel- plate electrode, and the value of the reactance element is controlled by comparing the generated DC self-biased voltage with the set value. CONSTITUTION:The excitation of plasma is performed by applying the output of the high frequency power source 5 on an electrode 8 through a DC blocking capacitor 4. The other electrode 2 is grounded through a variable capacitor or an inductance. When plasma is generated, the DC self-biased voltage is generated at an electrode 3, the DC self-biased voltage is applied to a differential amplifier 10 through the filters on a coil 7 and the capacitor 8, and the DC self-biased voltage is compared with the set voltage of a potentiometer 9, a motor 11 is operated in accordance with the result of the above comparison, and the DC self-biased voltage is adjusted to the set voltage by controlling the value of a variable impedance 6. When the high frequency power, vacuum pressure and gas flow rate which are optimum to the processing are determined, a stabilized etching can be performed while the DC self-biased voltage value is being controlled to an appropriate value during the period wherein plasma is generated. |
