| 摘要 |
PURPOSE: To make the distribution of generated plasma variable and make the distribution be optimum in each process by changing distribution ratio of high frequency electric power supplied to a high frequency coil or an electrode and also the phase difference of outputs. CONSTITUTION: A high frequency power supply 11 is fed to a variable and dividing-into-two distributor 12 and the set volume control is rotated, so that a variable capacitor can be set to have a proper capacity. The distributed electric power P1 with delayed phase from that of the electric power 11 by 3π+90 deg. is sent out to a variable phase shifter 13. The phase shifter 13 delays the phase of voltage (b) by 0-180 deg. corresponding to the rotary angle of the variable capacitors C21, C22 and the resulting voltage is sent out to the coil 36 through a matching box 14a. Further the voltage (a) sent out by the distributor 12 is sent to a coil 37 and the phase difference of the current flowing in the coils 36, 37 is detected by a phase detector 17. The voltage having the equivalent phase to that set by a phase setting part 19 is sent to a motor 20 through an operation amplifier 18 and the variable capacitors 21, 22 are controlled by the revolution of the motor 20 and thus the phase of the voltage b can be adjusted.
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