Circuit for adjusting the impedance of a plasma section to a high-frequency generator

Claim 1

A device for a steadily burning plasma comprising a high frequency generator designed for a load of approximately fifty Ohms and having a frequency of approximately 13.56 MHz; a plasma chamber (3) comprising a first electrode (7) and a sound electrode (4); a matching circuit (2) connecting said first and second electrodes (7,4) with said high frequency generator (1); said matching circuit (2) including two parallel resonant circuits (12, 13; 9, 10) coupled with a first fixed capacitance (11) and having capacitive input and output connections with second and third fixed capacitances (14, 8), respectively; said parallel resonant circuits (12, 13; 9, 10) being placed on one side of a ground connection, the two parallel resonance circuits (12, 13; 9, 10) each including a fixed inductor and a variable shunt capacitor, the parallel resonance circuit (12, 13) on the generator side having an inductance of 750 nH and a variable capacitance of 10 pF to 500 pF, and the load-side resonance circuit (9, 10) having an inductance of 500 nH and a variable capacitance of 10 pF to 500 pF, said two parallel resonant circuits (12, 13; 9, 10) being connected with one of their sides to ground and being placed in a cooling device.

Claim 2

A device for a steadily burning plasma comprising a high frequency generator designed for a load of approximately fifty Ohms and having a frequency of approximately 13.56 MHz; a plasma chamber (3) comprising a first electrode (7) and a sound electrode (4); a matching circuit (2) connecting said first and second electrodes (7,4) with said high frequency generator (1); said matching circuit (2) including two parallel resonant circuits (12, 13; 9, 10) coupled with a first fixed capacitance (11) and having capacitive input and output connections with second and third fixed capacitances (14, 8), respectively; said parallel resonant circuits (12, 13; 9, 10) being placed on one side of a ground connection, the two parallel resonance circuits (12, 13; 9, 10) each including a fixed inductor and a variable shunt capacitor, the parallel resonance circuit (12, 13) on the generator side having an inductance of 750 nH and a variable capacitance of 10 pF to 500 pF, and the load-side resonance circuit (9, 10) having an inductance of 500 nH and a variable capacitance of 10 pF to 500 pF, said two parallel resonant circuits (12, 13; 9, 10) being connected with one of their sides to ground and being placed in a cooling device.