| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a plasma impedance adjustment device which can keep treatment conditions constantly. <P>SOLUTION: With respect to a device that adjusts plasma impedance in a vacuum chamber, within this device, at least one electrode is connected to AC generator. This AC generator is a free-running type (oscillator), and its frequency corresponds to resonant frequency of an affecting load. This load contains fixed circuit elements and variable plasma impedance. When the plasma impedance changes, the resonance frequency also changes in connection with the plasma impedance. Therefore, the plasma impedance, can be changed by obtaining resonance frequency and by presetting a reference frequency value. As a result, for example, voltage, current, power, or inflow volume of gas can be changed as a function of the difference between the resonance frequency and the reference frequency value. <P>COPYRIGHT: (C)2003,JPO |
