JPS63258110A - Impedance matching device for high frequency plasma generator - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to an impedance matching device for a high frequency plasma generator.

[Conventional technology]

The impedance matching device of the conventional high frequency plasma generator is an L-type impedance matching circuit 8 as shown in FIG.
This method is generally known, in which slight load fluctuations are matched by the Paricore 3 and the variable capacitor 6, and in the case of large load fluctuations that exceed the variable capacitance range of the variable capacitor 3, a fixed capacitor/all the capacitors are used. 9 was installed in parallel with variable capacitor 3 each time.

Note that the maximum capacity of the variable capacitors 3 and 5 used is 500 PF due to their size, price, etc.

(Problem to be Solved by the Invention) However, in the impedance matching circuit 8 described above, when two or more loads are switched and used, even if matching is achieved within the adjustment range of the variable capacitor 3, matching is performed at the time of load switching. The V4 adjustment time of the variable capacitor 3 was wasted, and the discharge itself became unstable.

In addition, each time the variable capacitor 3 does not fall within the adjustment range of 500PF, the matching circuit box has to be opened and the fixed capacitor 9 removed, which is extremely troublesome and unsuitable for automation.

The present invention is intended to solve these problems, and its purpose is to provide a circuit that can easily and quickly perform impedance matching even when there is a large change in load or switching between multiple loads. It is in.

[Means for solving problems]

The impedance matching device of the high frequency plasma generation device of the present invention includes, in an impedance matching circuit between a high frequency power source and a high frequency plasma generation container, an impedance matching circuit from the high frequency power source to an input port of the matching circuit and ground.
It is characterized by comprising one or more fixed capacitors and a switch capable of switching these in two stages or in multiple stages.

[Effect]

According to the above configuration of the present invention, even if the impedance of the load changes significantly due to large fluctuations in the load, switching of the load, etc., even if the impedance of the load changes significantly due to large fluctuations in the load, load switching, etc. By simply switching the installed fixed capacitors in multiple stages, the capacitance can be changed significantly and quickly, making it possible to easily match impedance.

〔Example〕

An embodiment of the present invention will be described below with reference to FIG.

In FIG. 1, a high frequency power source is connected to an impedance matching circuit 80 input port 2 by a coaxial cable. Fixed capacitors 91, 92, and 93 are provided between the input port 2 and the ground via the variable capacitor 3 and the switch 10.

Further, a coil 4 and a variable capacitor 5 are arranged in series between the input port 2 and the output port of the impedance matching circuit 8, and a negative IV voltage is connected from the output port through the load switcher 11.
a71. Load b72. High frequency power is supplied to the load c73. The wiring between these uses copper plates.

Here, the output impedance of the high-frequency power source is Ro, and the load impedance is the pure resistance RL and the capacity CL.
In order to supply maximum power to the load, that is, to achieve matching, the impedance seen from the input port of the impedance matching circuit 8 toward the load side must be Ro. For this purpose, the capacitance C of the variable capacitor 3 and the reactance of the capacitance G1 of the variable capacitor 5 and the reactance of the capacitor 4 are determined by the following formula. (The wL-1/wCT of the formula is almost determined by the shape of the plasma generation container, etc., and subsequent load fluctuations can be adjusted and absorbed by the variable capacitor 5.) The 1/wCM of the formula is largely determined by the shape of the container and the load fluctuations mentioned above. The deviation may exceed the adjustment range of the variable capacitor 3.

In this embodiment, the above circuit is used in a sputtering apparatus, and the load a7
J is a metal magnetron cathode, load b72 is a ceramic magnetron cathode, and load C73 is for sputter etching, that is, applying high frequency to the substrate holder. Here, when the load switcher 6 is connected to the load a71, the capacitor switcher lO is connected to the fixed capacitor 91 (300PF
) and similarly load b72. When connected to load c73, the capacitor switch also switches to fixed capacitor 02 (70
0PF), 93 (100OPF).

By doing this, the variable capacitor 3 does not have to be moved much, and furthermore, matching can be easily and quickly performed even when the maximum capacity of the variable capacitor is exceeded.

(Effects of the Invention) As described above, according to the present invention, a fixed hole is arranged in advance between the high frequency power supply side input port of the impedance matching circuit and the ground, and by switching and using this, a plurality of To achieve the effect of easily and quickly achieving impedance matching even when there is load switching, large load fluctuation, etc.

[Brief explanation of drawings]

FIG. 1 is a configuration diagram of an impedance matching device according to the present invention. Second
The figure is a configuration circuit diagram of a conventional impedance matching device. ■...High frequency power supply 2...Impedance matching circuit input port 3.5...
・Varicon 4...Coil 6...Impedance matching circuit output port door...Load 71, 72.73...Loads a, b, c8...Impedance matching circuit section 91.92.03...Fixed Capacitor 10...Capacitor switching device 11...Load switching device and above Applicant: Seiko Epson Corporation Kanryo no Bee! (No change to FC contents) Figure 1 Figure 2 Procedural amendment form) % formula % Impedance matching device 3 of high frequency plasma generator, person making the correction Representative director Tsuneya Nakamura 4, agent 5, person making the correction order Date 7, subject to amendment as per attached sheet

Claims (1)

[Claims] (1) In an impedance matching circuit between a high frequency power source and a high frequency plasma generation container, between the input port from the high frequency power source to the impedance matching circuit and ground,
1. An impedance matching device for a high-frequency plasma generator, comprising at least one fixed capacitor and a switch capable of switching these in two stages or in multiple stages.