Patent ID: 8267041

Claim:
A plasma treating apparatus adapted to provide a predetermined plasma treatment to an object to be treated, comprising: a processing chamber capable of being vacuumed; an object holding means adapted to hold an object; a high frequency power source adapted to generate high frequency voltage; a plasma gas supplying means adapted to supply a plasma generating gas to be treated to generate plasma to the processing chamber; a first plasma electrode and a second plasma electrode providing a pair of plasma electrodes disposed to apply high frequency voltage to plasma generating gas supplied from the plasma gas supplying means and thereby generate plasma in the processing chamber, and connected to the output side of the high frequency power source; a high frequency matching means, provided between the pair of plasma electrodes and the high frequency power source to connect the electrodes and the power source such that none of the high frequency matching means and the electrodes are grounded and each electrode is brought into an excited electrode state in a high frequency manner, for impedance matching based upon a load acting on the high frequency power source as a result of plasma generated in the processing chamber by the plasma electrodes, said load being detectable as a reflected wave at the plasma electrodes, the high frequency matching means including: a wave detector for detecting said reflected wave and outputting a signal representative of said wave; a high frequency matching circuit disposed such that the wave detector is between the high frequency matching circuit and the high frequency power source, the high frequency matching circuit having at least one first reactance element, and a control unit for causing, based on a reflected wave signal output from the wave detector, the high frequency matching circuit to match an impedance of said load by causing the plasma electrodes to generate a composite potential; and wiring for connecting the plasma electrode to the high frequency power source through the high frequency matching means, the wiring including: a first wire extending from the first plasma electrode through the high frequency matching circuit to the wave detector, the first wire continuing to connect the wave detector to the high frequency power source to thereby connect the first plasma electrode to the output side of the source, and a second wire extending from the second plasma electrode through the high frequency matching circuit to the detector, the second wire continuing to connect the wave detector to the high frequency power source to thereby connect the second plasma electrode to the output side of the source wherein the first wire and the second wire are connected to each other through the at least one first reactance element, and neither the first wire nor the second wire is grounded.