Matching unit and plasma processing system

1. A matching unit, provided between a high frequency power supply and a high frequency load introducing part, for matching an impedance of a high frequency load with a transmission path impedance, said matching unit comprising:

a resonance rod for transmitting a high frequency energy from a high frequency power supply to a high frequency load introducing part;

a variable capacitor, connected to said resonance rod and said high frequency load introducing part in series, for adjusting an imaginary part of an impedance complex number;

a housing which is provided outside of said resonance rod and which is grounded; and

a variable coupling feeding part for exciting a high frequency energy to said resonance rod and for adjusting a real part of the impedance complex number,

wherein said variable capacitor and said variable coupling feeding part are adjusted so that a series resonance circuit is formed between said high frequency power supply and said high frequency load in a state that the impedance of said high frequency load is matched with the transmission path impedance.

2. A matching unit as set forth in claim 1 , wherein said high frequency load introducing part is a plasma producing electrode, and said high frequency load is plasma.

3. A matching unit as set forth in claim 1 , which further comprises control means for controlling said variable capacitor and said variable coupling feeding part.

4. A matching unit as set forth in claim 1 , wherein said resonance rod and said housing are provided so as to be coaxial with each other.

5. A matching unit as set forth in claim 1 , wherein said variable coupling feeding part has a link coil for supplying a high frequency power to said resonance rod by the inductive coupling.

6. A matching unit as set forth in claim 5 , wherein said variable coupling feeding part adjusts impedance by adjusting the distance between said link coil and said resonance rod.

7. A matching unit as set forth in claim 5 , wherein said variable coupling feeding part has a variable capacitor which is connected to said link coil, and adjusts impedance by adjusting said variable capacitor.

8. A matching unit as set forth in claim 7 , wherein said link coil is cylindrical, and is provided so as to surround said resonance rod.

9. A matching unit as set forth in claim 1 , wherein said variable coupling feeding part has a connection member which is movably connected to said resonance rod and which supplies a high frequency power to said resonance rod, and a moving mechanism for moving a connection member in longitudinal directions of said resonance rod, said variable coupling feeding part adjusting a real part of an impedance complex number by adjusting the position of said connection member by said moving mechanism.

10. A matching unit as set forth in claim 1 , wherein said variable coupling feeding part has a connection member which is movably connected to said resonance rod and which supplies a high frequency power to said resonance rod, and a variable capacitor which is arranged in series to said connection member, said variable coupling feeding part adjusting a real part of an impedance complex number by adjusting said variable capacitor.

11. A matching unit as set forth in claim 1 , wherein said variable capacitor connected to said resonance rod and said high frequency load introducing part in series has a motor for changing the capacitance of said variable capacitor, said motor being provided on the side of the other end via a rotation shaft provided in said resonance rod.

12. A matching unit as set forth in claim 1 , wherein said high frequency power supply has a frequency of 70 MHz or higher.

13. A matching unit as set forth in claim 1 , wherein said variable capacitor connected to said resonance rod and said high frequency load introducing part in series is mounted directly on said plasma producing electrode.

14. A matching unit as set forth in claim 13 , wherein said variable capacitor is detachably mounted by a multi-plane contact member having a plurality of contacts.

15. A matching unit as set forth in claim 13 , wherein said variable capacitor has a structure that one electrode of said variable capacitor serves as a part of said plasma producing electrode and that the other electrode is provided via air serving as an insulating layer.

16. A matching unit, provided between a high frequency power supply and a plasma producing electrode, for matching an impedance of a high frequency load with a transmission path impedance, said matching unit being mounted directly on said plasma producing electrode,

said matching unit having a variable capacitor for adjusting an imaginary part of an impedance complex number of a high frequency load, said variable capacitor being mounted directly on said plasma producing electrode.

17. A matching unit as set forth in claim 16 , wherein said variable capacitor being detachably mounted by a multi-plane contact member has a plurality of contacts.

18. A matching unit as set forth in claim 16 , wherein said variable capacitor has a structure that one electrode of said variable capacitor serves as a part of said plasma producing electrode and that the other electrode is provided via air serving as an insulating layer.

19. A plasma processing system comprising:

a chamber for housing therein an object to be processed;

first and second electrodes which are provided so as to face each other in said chamber;

a high frequency power supply for supplying a high frequency power to said first electrode;

a matching unit, provided between said high frequency power supply and said first electrode, for matching a plasma impedance with a transmission path impedance;

exhaust means for maintaining the interior of said chamber in a predetermined reduced pressure state; and

process gas feed means for feeding a process gas into said chamber,

said plasma processing system forming a high frequency electric field between said first and second electrodes by said high frequency power to produce the plasma of said process gas to carry out a plasma processing,

said matching unit comprising:

a resonance rod for transmitting a high frequency energy from said high frequency power to said first electrode;

a variable capacitor, connected to said resonance rod and said first electrode in series, for adjusting an imaginary part of an impedance complex number;

a housing which is provided outside of said resonance rod and which is grounded; and

a variable coupling feeding part for exciting a high frequency energy to said resonance rod and for adjusting a real part of the impedance complex number,

wherein said variable capacitor and said variable coupling feeding part are adjusted so that a series resonance circuit is formed between said high frequency power and the ground via said plasma in a state that the impedance of a high frequency load is matched with a transmission path impedance.

20. A plasma processing system as set forth in claim 19 , wherein said high frequency power supply has a frequency of 70 MHz or higher.

21. A plasma processing system comprising:

a chamber for housing therein an object to be processed;

first and second electrodes which are provided so as to face each other in said chamber;

a high frequency power supply for supplying a high frequency power to said first electrode;

a matching unit, provided between said high frequency power supply and said first electrode, for matching a plasma impedance with a transmission path impedance;

exhaust means for maintaining the interior of said chamber in a predetermined reduced pressure state; and

process gas feed means for feeding a process gas into said chamber,

said plasma processing system forming a high frequency electric field between said first and second electrodes by said high frequency power to produce the plasma of said process gas to carry out a plasma processing,

said matching unit being mounted directly on said first electrode and having a variable capacitor for adjusting an imaginary part of an impedance complex number of high frequency load, said variable capacitor being mounted directly on said first electrode.