JPH01197999A - Plasma generating device - Google Patents

Abstract

PURPOSE:To make it possible to generate plasma at a high density by applying a microwave magnetic field circularly polarized by electrons existing in plasma, and applying a magnetic field in the direction where a right-handed screw advances to the rotation direction of the circularly polarized magnetic field. CONSTITUTION:A microwave passing through a mode converter 24 becomes a circularly polarized wave having a vibration direction of a magnetic field rotating in the direction of a right-handed screw to the advancing direction of the microwave. By introducing thus generated microwave including the circularly polarized wave of the magnetic field to a discharge chamber 8 having a magnetic field directing down applied by solenoids 17-a-17-c, the microwave is absorbed by the precession motion of electrons in plasma, because the direction of the magnetic field Hdc and the direction of the circularly polarized wave of the microwave magnetic field are similar to the advancing direction and the rotation direction of the right-handed screw. This makes electrons in plasma have a very high energy, and ionization of discharge gas is accelerated, thereby a high density plasma can be generated.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to an ion source, a plasma device using microwave discharge for CVD, etching, ion beam exposure, etc. Regarding an enhanced plasma generator.

BACKGROUND OF THE INVENTION In recent years, microwave discharges have been used to generate high-density plasmas.

An example of a microwave ion source (eg.
,Set,Ins+trum, ,67(@
p1526 (1s86)) is shown in FIG.

In FIG. 16, reference numeral 1 denotes a 2.45 GHz microwave generation oscillator, and the microwave generated by this is transmitted through a rectangular waveguide 2 and a coaxial tube 6 consisting of an inner conductor 3 and an outer conductor 4. As a result, plasma 9 is generated by co-supplying into a discharge chamber 8 consisting of an inner conductor 6 and an outer conductor 7 connected to this coaxial tube 6.

A ceramic window 1o with low dielectric loss for vacuum sealing is arranged between the coaxial tube 6 and the discharge chamber 8.
and the vacuum chamber 11 are electrode systems 12-a, 12-b, for extracting ions from the plasma 9.
12-c is arranged.

13. 14, 15 and 16 are parts of the microwave transmission circuit, each consisting of an isolator, a power monitor, a choke flange, and a shorting plate.

17-a, 17-b, and 17-c are solenoids for generating electric discharge.

These solenoids 17-a to 17-0 allow a maximum of about 2000 Gauss and a minimum of about 100 Gauss on the central axis of the discharge tube 8.
A mirror magnetic field of approximately 0 Gauss is formed to confine electrons and increase the density of plasma.

In this case, the direction of the magnetic field generated by the solenoids 17-&-17-C does not essentially change whether it is directed upward or downward in FIG. 16.

In addition, in microwave discharge, electron cyclotron resonance (EC) is often used to increase the absorption of microwaves into the plasma.
R) is used.

ECR causes electrons to move circularly along magnetic field lines, and causes resonance absorption of electromagnetic waves of a frequency equal to the rotational frequency determined by the magnetic field strength.A microwave of 2.45 GHz causes resonance absorption in a magnetic field of 875 Gauss.

Since the microwave transmission circuit, including the discharge chamber, has a cutoff frequency at which electromagnetic waves of lower frequencies are not transmitted, the size of the transmission circuit is determined by the frequency of the microwave used.

Therefore, in a plasma device in which a rectangular or circular waveguide or cavity resonator is used as a discharge chamber, the size of the discharge chamber is limited by the frequency of the microwave used.

However, coaxial tubular waveguides do not have a cutoff frequency, so if a coaxial tube is used in the discharge chamber as in the conventional example shown in Figure 16, a discharge tube of any diameter can be used, which is an excellent design feature. Has characteristics.

For example, in order to further increase the amount of ions extracted from the above-mentioned ion source, it is necessary to increase the density of the plasma. As described above, in order to generally improve the performance of a plasma device, it is necessary to increase the plasma density.

In order to increase the density of the plasma, it is sufficient to increase the absorption of the microwave power input into the discharge chamber into the plasma.

Therefore, resonance absorption by ECH is utilized, and in order to further increase the absorption rate, the conventional example shown in FIG. 16 uses a mirror magnetic field of a maximum of about 2000 Gauss as described above.

Problems to be Solved by the Invention However, in order to apply such a strong magnetic field, it is necessary to flow a large current through the solenoid, which poses a problem in that the device becomes larger and the power consumption increases at the same time.

SUMMARY OF THE INVENTION In view of the above problems, it is an object of the present invention to provide a highly efficient glazma generation device with a simple configuration.

Means for Solving the Problems In order to solve the above problems, the present invention provides an oscillator that generates microwaves as discharge power, a microwave transmission circuit that transmits the microwaves, and a discharger that discharges the transmitted microwaves. A circularly polarized magnetic field generated by the microwave is installed in the section from the oscillator to the discharge chamber, and the circularly polarized magnetic field generated by the circularly polarized magnetic field generated by the circularly polarized wave generator is placed in the discharge chamber. The structure is such that a magnetic field is applied in the direction in which the screw advances.

Function The present invention applies a circular microwave magnetic field to electrons existing in plasma, and applies the magnetic field in the direction in which a right-handed screw advances with respect to the rotation direction of the circularly polarized magnetic field, thereby causing the electrons to precess. Absorb microwaves by exercising.

Embodiments To explain the present invention in detail, the principle thereof will first be explained.

In plasma, high-energy electrons collide with the discharge gas, causing the discharge gas to become! It is caused by doing. Therefore, in order to generate high-density plasma, it is necessary to give higher energy to the electrons.

The present invention promotes ionization and generates high-density plasma by absorbing high energy by electrons.

As shown in FIG. 12a, the electron 18 has a magnetic moment l-M due to its spin. and has angular momentum I0.

Therefore, when a magnetic field Hdo is applied to the electrons 18 to align the spin axes of the electrons 18, and a microwave magnetic field is applied in a direction perpendicular to the magnetic field HdC, the electrons will move into the magnetic field HdC as shown in Figure 12C.
Rotate around the direction (z-axis direction) in the direction of the arrow. This is Larmor precession, and the angular frequency of rotation ω is given by the following equation.

ω'=;e@Hdc/2yrme=groan...war/C...
・−・φ・(1) (e: electron charge, m: electron mass) Then, the applied microwave magnetic field H rotates in the direction of the dashed arrow at right angles to the second sleeve as shown in Figure 12C. When the angular frequency is equal to ω in equation (1), electrons strongly absorb magnetic resonance of this microwave and have high energy.

However, this magnetic resonance occurs when the direction of rotation of the circularly polarized wave of the microwave magnetic field H and the direction of the applied magnetic field Hda are the same as the direction of rotation of the right-hand screw and the direction of movement of the right-hand screw. In other words, the microwave magnetic field H in Fig. 12C
If the direction of rotation is opposite, magnetic resonance will not occur.

Note that the relationship in equation (1) is based on electron cyclotron resonance (EC
This is almost the same as the relational expression for resonance absorption by R).

That is, for microwaves of 2.46 GHz that are normally used for electric discharge, the precession also resonates at about 875 Gausg.

This microwave absorption phenomenon caused by the magnetic resonance of precession is utilized in isolators, which are microwave circuit components.

In order to assist in understanding the present invention, a brief description of a rectangular waveguide type magnetic resonance absorption isolator will be given below.

An isolator is an element that allows microwaves to pass in one direction, but blocks microwaves in the opposite direction.

FIG. 13a shows the instantaneous magnetic field H of microwaves transmitted in two directions within the rectangular waveguide 19.

The microwave is in the TEo mode within the rectangular waveguide, and the magnetic field H is traveling in two axial directions, alternating between clockwise and counterclockwise rotations, as shown in the figure.

FIG. 13 is a view of FIG. 13a from above.

A point close to the right side surface in the waveguide 19 is designated as A, and a point close to the left side surface is designated B, and let us consider the direction of the magnetic field H when the microwave passes through these points.

The magnetic field H of the microwave does not rotate left and right, but moves in two directions, but the change in the state of the magnetic field H that passes through points A and B over time (!) is as follows: This is the same as the change in the magnetic field H and state seen in the direction opposite to the two axes passing through B (in the direction of the dashed arrow).Therefore, the rectangular waveguide 19
If the direction of the microwave magnetic field on the broken line A and the broken line B in each part 1.2 and 3.4 of Figure 13 is indicated by arrows, the directions will be as shown in A' and B'. ing.

The arrows A' and B' indicate the direction of vibration of the microwave magnetic field, and when A/ and 13/ are put together, it becomes as shown in Fig. 13C.

That is, as shown in the figure, when viewed from above the rectangular waveguide 19, the microwave magnetic field passing through point A rotates clockwise, and conversely, the microwave magnetic field passing through point B rotates counterclockwise. It has become.

Therefore, as shown in FIG. 13d, a ferromagnetic material ferrite 20 is placed near the left side surface of the rectangular waveguide 19, that is, the part where counterclockwise circularly polarized waves are generated, and further,
When a magnetic field Hda is applied in the direction of the arrow, when microwaves try to pass in the biaxial direction (direction from the front to the back of the page), electrons in the ferrite generate magnetic resonance and absorb the microwaves.

That is, microwaves traveling in the z-axis direction are blocked. Conversely, when the microwave propagates in the opposite direction to the two axes, a clockwise circularly polarized wave as shown at A' in Figure 13C is generated in the ferrite part, but the magnetic field Hda is in the same direction as before. Therefore, no magnetic resonance occurs and microwaves can pass through.

This is the principle of a rectangular waveguide type magnetic resonance absorption isolator.

Next, we will explain the mode of microwaves transmitted within a coaxial tube consisting of an inner conductor and an outer conductor.

Fig. 14 shows a coaxial tube 2 consisting of an inner conductor 21 and an outer conductor 22.
3, and the distribution of electric field E (solid line arrow in the figure) and magnetic field H (broken line arrow in the figure) in the TEM mode normally used in the case of a coaxial tube.

In the TEM mode, the electric field E exists radially and the magnetic field H exists concentrically, and they vibrate by changing their directions.

Waveguides, including coaxial tubes, are designed and used so that the microwave mode (electromagnetic field state) transmitted inside the waveguide is in the simplest (low-order) state. This is the basic mode,
In the case of a coaxial tube, it is the TEM mode.

However, higher-order modes, such as those shown in FIG. 14b-f, may also exist in the coaxial tube.

Similar to FIG. 14a, FIGS. 14b to 14f show the electric field as a solid line and the magnetic field as a broken line.

On the other hand, in a waveguide, the cutoff frequency of higher-order modes is higher than the cut-off frequency of lower-order modes. In other words, if we use a microwave whose cut-off frequency is the lowest in the lowest-order mode (fundamental mode) and lower than the cut-off frequency of the higher-order modes, higher-order modes will be generated by foreign objects in the waveguide. However, these higher-order modes cannot pass through the waveguide and disappear.

Thus, waveguides are designed and used to transmit only the fundamental mode. Note that there is no cutoff frequency in the TEM mode, which is the fundamental mode of the coaxial tube.

Whether higher-order modes can pass depends on the frequency and the size of the waveguide.

In the case of a coaxial tube consisting of an inner conductor 21 with a radius of a and an outer conductor with a radius of 1, TE11. TE21. TE3. Cutoff wavelength λ of the mode. (The wavelength corresponding to the cutoff frequency) is as shown in FIG.

For example, if b/a = 2.3.10w12m, then b
is larger than about 2.7 crII, the TE11 mode exists and can be passed.

Based on the above phenomenon, a first embodiment of the present invention will be described with reference to FIG.

In FIG. 1, the same components as those in the conventional example shown in FIG. 16 are given the same numbers. Further, in FIG. 1, the oscillator 1, rectangular waveguide 2, etc. shown in FIG. 16 are omitted.

In this embodiment, the solenoid 17-a.

The magnetic field Hda generated by 17-b and 17-c is applied in the downward direction indicated by the arrow in the figure.

In this example, the frequency of the microwave is 2.46GH
z, the outer diameter of the inner conductor 3 constituting the coaxial pipe 6 is 2.2 cm, the inner diameter of the outer conductor is 6.0 crn, and TE11 based on FIG.
It is designed to be sized so that the mode can be transmitted. Further, the inner conductor 6 and outer conductor 7 in the discharge chamber 8 are also the same size as the coaxial tube 5. The TEM mode is transmitted to the coaxial tube 6 in a downward direction in the figure, but is converted into the fiTEL mode by the mode converter 24.

The detailed structure of the mode converter 24 used in this embodiment is shown in FIG. In Figure 2 a, it is on the left (111
TEM mode microwave is on from 1, TE is on the right side,
1 mode and leaves.

3 is an inner conductor, and 24-a is a T made of a thin metal plate.
EM mode filter, 24-b is a mode converter made of metal wire, 24-C is TE1 made of a thin metal plate.
It is a 1 mode filter.

Generally, even if a metal plate is inserted at right angles to the vibration direction of the microwave electric field within the waveguide, the microwaves will pass through without being reflected. However, if the metal plate is not perpendicular to the direction of vibration of the electric field, the microwaves will be reflected. Two mode fills 24-d and 2
4-C utilizes this principle, in which the TEM mode microwave incident from the left side of FIG. 2a passes through the TEM mode filter 24-a without any problem (TEM-! of FIG.
2.45G to the wire of the need reference mode converter 24-b
Generates a current whose vibration direction changes at Hz.

The wire 24-bl is oriented in the radial direction, and a current oscillates in the radial direction in this wire to newly radiate microwaves having an electric field component equal to the direction of the oscillation.

A part of the wire 24-b2 is oriented in the circumferential direction, and radiates microwaves having an electric field component in the circumferential direction as in the above case. As a result, the mode converter 24-b emits microwaves having electric field components in the radial direction and the circumferential direction, that is, TE4.
．． mode (see Figure 14) is strongly radiated. This T
The Hl mode passes through the TE11 mode filter 24-C and exits to the right side of the figure.

On the other hand, TE4. The mode microwave is reflected by the TEM mode filter 24-a,
It goes to the TE11 mode filter 24-C.

The mode converter 24-b also partially emits TEM mode, but TE4. The TEM mode radiated in the mode filter 24-C direction is reflected by the TE11 mode filter 24-C.

Therefore, only the TE, 1 mode microwaves exit from the mode converter 24.

In FIG. 1, the microwave that has passed through the mode converter 24 is turned into a circularly polarized wave by the phase shifter 25 in which the vibration direction of the magnetic field rotates in a right-handed screw direction with respect to the direction in which the microwave travels. The detailed structure of the phase shifter 26 consists of dielectric plates 26 arranged as shown in FIG.

The microwave that has passed through the mode converter 24 is a linearly polarized wave, and the oscillation direction of its electric field E consists of electric field components Ea and Eb that are perpendicular to each other, as shown in FIG. 3a.

In Figure 3a, 3 and 4 are the inner conductor and outer conductor of the coaxial pipe,
26 is a dielectric plate.

In Fig. 3d, if the microwave transmission direction is the direction toward the other side of the paper, and this is the biaxial direction, the microwave electric field before entering the phase shifter 26 has a phase as shown in Fig. 3. consists of Ea and Eb, which are equal and perpendicular to each other.

However, when passing through the phase shifter 26, the phase of the electric field Eb parallel to the dielectric plate 26 is delayed as shown in FIG. 3C, and as a result, the direction of vibration of the electric field rotates in the direction of the arrow in FIG. 3C. This rotation is in a right-handed screw direction with respect to the microwave transmission direction (biaxial direction).

On the other hand, since the direction of vibration of the electric field and the direction of vibration of the magnetic field are always at right angles, when the direction of vibration of the electric field rotates as shown in FIG. 3C, the direction of vibration of the magnetic field also rotates. That is, the vibration direction of the magnetic field rotates in the right-handed direction with respect to the microwave transmission direction, resulting in circularly polarized waves. The state of circular polarization of the microwave magnetic field at the position of point A near the output of the phase shifter 26 in FIG. 1 will be explained with reference to FIG. 4.

In FIG. 4, the microwave electric field E is shown by a solid line arrow, the magnetic field H is shown by a broken line arrow, and the direction of the magnetic field H at point A is shown by a solid line arrow on the left side of the figure.

The microwave is transmitted toward the front side of the page.
Figures a, b, c, and d represent temporal changes in the electric field E and magnetic field H in the same cross section at point A. Note that the direction of circularly polarized waves is the direction of the arrow shown above each figure.

The direction of the magnetic field at point A in FIGS. 4a, b, c, and d rotates to the lower left, right, and upper, as shown in FIG. 4e. That is, the magnetic field rotates in a right-handed screw direction with respect to the transmission direction.

As is clear from Fig. 14, the circularly polarized wave of such a magnetic field is
This does not occur in the fundamental TEM mode normally used for coaxial tubes. However, circularly polarized waves can be generated in the cwf shown in FIG. 14, which is a higher order mode of the coaxial tube, including the TE and 1 modes shown in this embodiment.

Now, the microwave having the circularly polarized magnetic field generated in this way is transferred to the solenoid 17-a in FIG.

17-b, 1 When introduced into the discharge chamber 8 having a downward magnetic field H applied by arc C, the direction of the magnetic field Hda and the direction of the circularly polarized wave of the microwave magnetic field are equal to the direction in which the right-handed screw advances and the direction of rotation. Therefore, the electrons in the plasma precess and absorb the microwaves.

In particular, for microwaves of 2.45 GHz, the magnetic field Hda
When it is set to 875 Gauge, magnetic resonance due to precession occurs along with ECR resonance of electrons, and almost all of the incident microwaves are absorbed. As a result, the electrons in the plasma have very high energy and can promote the ionization of the discharge gas and generate high-density goufsma.

Although this embodiment has been described using the TEL mode, other higher-order modes shown in FIG. 14 may be used as described above. Moreover, any mode other than that shown in FIG. 14 may be used as long as it can generate circularly polarized magnetic waves.

In this embodiment, circularly polarized waves of the magnetic field are generated using the mode converter 24 and the phase shifter 26 described above, but other methods may also be used, and these are arranged not in the coaxial tube 5 but in the discharge chamber 8. You may do so.

In addition, solenoids 17-a, 17-b, 17
Although the magnetic field Hda caused by -a is directed downward in FIG. 1, it may be directed upward, and the direction of rotation of the circularly polarized wave of the microwave magnetic field may be reversed. Naturally, the magnetic field Hda may be applied by a permanent magnet.

Further, in this embodiment, a case has been described in which a coaxial tube 6 and a discharge chamber 8 consisting of an inner conductor 6 and an outer conductor 7 are used, but other types of waveguides and discharge chambers may be used.

In addition, FIG. 6 shows the case of a magnetic field discharge in which the electrons 27 perform a cyclotron circular motion (FIG. 6 a), and the case where the electrons 27 precess according to the present invention at the same time as the cyclotron circular motion (FIG. 6 b). The trajectory is schematically shown. Note that Hda is the applied magnetic field.

A second embodiment of the present invention will be described with reference to FIG.

In FIG. 6a, the same components as in FIG. 1 are given the same numbers. Further, in FIG. 6, only the waveguide portion and the discharge chamber portion are illustrated, and the other portions are omitted.

In FIG. 6a, 28 is a circular waveguide whose inner part is shown in FIG.
The signal is transmitted in E.1 mode (the solid line arrow indicates the electric field, and the broken line arrow indicates the magnetic field), and a circularly polarized wave of the magnetic field is generated in the same direction of rotation as in the embodiment shown in Fig. 1 using a phase shifter 29 using a dielectric material. .

3o and 31 are the inner conductor and outer conductor that constitute the coaxial pipe 32,
The tip of the inner conductor 30 is sharpened to suppress reflection.

The circularly polarized microwave is here transmitted to the coaxial tube, and the sixth
It passes through the taper part 33 and the coaxial tube 6, which change the size of the coaxial tube, while being circularly polarized in the coaxial tube TE11 mode in Figure C.
It is sent to the discharge chamber 8. A magnetic field Hda is applied to the discharge chamber 8 in the direction shown, and a high-density gufsma is generated as in the first embodiment.

In this way, the circularly polarized wave of the microwave magnetic field may be generated using a circular waveguide, and the circular waveguide 28 may be used instead of using the coaxial tube 6 or the discharge chamber 8 of the type shown in FIG. It may be connected directly to the tubular discharge chamber.

A third embodiment of the present invention will be described with reference to FIG. In FIG. 7, the same components as in FIG. 1 are given the same numbers. Also, in FIG. 7, a part of the coaxial tube 6 and a discharge chamber 8 are shown.
Some parts are shown and others are omitted.

In this embodiment, an inner conductor 34 formed in a spiral shape is used as a means for generating circularly polarized waves of a microwave magnetic field. The inner conductor formed in a spiral shape generates good circularly polarized waves when the length of the circumference of the spiral is approximately equal to the wavelength of the microwave, similar to the spiral antenna used for microwave communication antennas. .

Note that the shape of the spiral of the inner conductor 34 is not limited to the shape shown in FIG. It doesn't matter if it is.

Before explaining the fourth embodiment of the present invention, a coaxial isolator will be explained.

In Fig. 8a, a metal plate 38 is arranged between the inner conductor 36 and outer conductor 37 of a coaxial pipe 36, and the microwave is incident from the right side of the figure in TEM mode and transmitted in two axial directions. Suppose there is. Since it is a TEM mode, the electric field E is generated radially in the radial direction, but the inner conductor 36 and the outer conductor 37 are
No electric field E can be generated in the portions that are in contact with each other.

On the other hand, the magnetic field H is always perpendicular to the electric field Z, and since the electric field E does not exist near the metal plate 38, the magnetic field H is bent into a saddle shape as shown in FIG. 8a. The shape of this magnetic field H is the same as that shown in FIG. 13 when viewed from above by cutting the coaxial tube 36 from the center in the radial direction of the metal plate 38 and developing it.

Therefore, just as we investigated the direction of the magnetic field at points 1 to 4 in Figure 13, we examine the direction of the magnetic field at points 1 to 4 parallel to the z-axis through point A in Figure 8. , in the direction of the arrows shown below points 1 to 4 in FIG.

FIG. 8d illustrates this change in direction, and it is clear that a circularly polarized wave rotating counterclockwise is generated.

Therefore, if a ferrite is placed at point A and a magnetic field Hdc is applied in the direction of the arrow in FIG. However, for microwaves traveling in the opposite direction to the two axes, absorption does not occur because the direction of rotation of the circularly polarized waves of the magnetic field is reversed, and the microwave acts as an isolator (for example, , 146).

Therefore, a saddle-shaped magnetic field H as shown in Fig. 8a is generated in a vacuum without using ferrite, and the magnetic field Hda is directed in the direction shown in Fig. 8C.
When is applied, the electrons present in the portion 39 cause magnetic resonance absorption, and high-density plasma is generated.

The fourth embodiment shown in FIG. 9 utilizes this.

In FIG. 9, the same components as in FIG. 1 are given the same numbers, but the size of the coaxial tube 6 and discharge chamber 8 is TE4. We do not care about the possible sizes of modes. Also, the 9th
In the figure, only the coaxial tube 6 and the discharge chamber 8 are shown, and the others are omitted. However, in this embodiment, the solenoids around the discharge chamber 8 are not used. In Figure 9a,
39 is a metal plate. FIG. 9 is a sectional view of FIG. 9a, in which a magnetic field Hda is applied by a permanent magnet 40 in the direction of the arrow.

With this configuration, microwaves are resonantly absorbed in the portion 41, and high-density plasma is generated. However, plasma is 41
It is not only present in the discharge chamber 8, but due to diffusion.
spread throughout the interior.

In this embodiment, the permanent magnet 40 is used as the means for generating the magnetic field Hdo, but an electromagnet may also be used, or a solenoid may be arranged around the discharge tube 8 as shown in FIG.

A sixth embodiment of the present invention will be described with reference to FIG.

This embodiment is based on the embodiment shown in FIG. 9, in which a rectangular ion beam is extracted, and the same components as in FIG. 9 are given the same numbers. A rectangular slit 42 for extracting ions is provided in the outer conductor 7 of the discharge chamber 8, and an extraction electrode system 12-a, 12-b similar to that shown in FIG. 1 is provided.
, 12-c are arranged.

This principle is exactly the same as the embodiment shown in FIG. 9, so its explanation will be omitted.

In this way, the resonance absorption type isolator can be used as a high-density plasma generation device.

Figure 11a shows an example of another type of coaxial tube type isolator.
- Shown in f. In FIG. 11, 43 is a coaxial tube consisting of an inner conductor 44 and an outer conductor 46, and 46 is a dielectric.

By disposing a dielectric material between the inner conductor 44 and the outer conductor 45 as shown in FIG. 11 awd, or by making the inner conductor 44 and the outer conductor 45 eccentric as shown in FIG.
A saddle-shaped magnetic field H similar to that shown in the figure can be generated.

Therefore, by making the discharge chamber portion of the embodiment shown in FIGS. 9 and 10 as shown in FIG. 11 awf, a high-density plasma generating device can be obtained.

Effects of the Invention According to the present invention, absorption of microwaves into plasma can be dramatically increased with a magnetic field strength comparable to that of ECR.
High density plasma can be generated.

Therefore, less current is required to flow through the magnetic field generation solenoid, and a high-performance plasma generation device can be obtained with a small device and a small squid used.

Furthermore, since the required magnetic field is on the order of ECR, a permanent magnet can also be used to generate the magnetic field, which has the effect of requiring extremely low power consumption.

[Brief explanation of the drawing]

Fig. 1 is a schematic diagram of a plasma generator according to the first embodiment of the present invention, Fig. 2 is a perspective view of the components, Fig. 3 is a principle diagram of the constituent parts, and Fig. 4 is a mode diagram of circularly polarized waves. , FIG. 6 is an electron trajectory diagram, FIG. 6 is a schematic diagram showing the second embodiment of the present invention, FIG. 7 is a schematic diagram of the third embodiment of the present invention, and FIG. 8 is a coaxial tube. 9 is a schematic diagram of a fourth embodiment of the present invention, FIG. 10 is a schematic diagram of a sixth embodiment of the present invention, and FIG. 11 is a schematic diagram of a coaxial tubular isolator system. Figure 12 is a schematic diagram of the precession of electrons, Figure 13 is a principle diagram of a rectangular waveguide isolator, Figure 14 is a mode diagram of microwaves in a coaxial tube, and Figure 16 is the size of the coaxial tube. FIG. 16 is a schematic diagram showing the configuration of a conventional example. 6...Coaxial tube, 8...Discharge chamber, 17.
... Solenoid, 24 ... Mode converter, 26 ... Phase shifter. Name of agent Patent attorney Satoshi Nakao and one other person Figure 5 ↓ Hadc Figure 6 (a) Figure 7 00 v Q
＼ノFigure 9Figure 10=Shin J'1cIzb17L:L Figure 11Figure 12Figure 13Figure 14 ((7,) (b)Tshint-':
7Enmogi TEa< +-￥
TE3+ t-YTMu+Yo ￥2
7M2 E@-g Figure 15 Last Figure 16

Claims (6)

[Claims] (1) An oscillator that generates microwaves that are discharge power;
It consists of a microwave transmission circuit that transmits the microwave and a discharge chamber that discharges the transmitted microwave, and has a circularly polarized wave generating device for the magnetic field of the microwave in the section from the oscillator to the discharge chamber, and a plasma generation device in which a magnetic field is applied in a direction in which a right-handed screw advances with respect to a rotational direction of a circularly polarized magnetic field generated by the circularly polarized wave generator in a discharge chamber. (2) The plasma generating device according to claim 1, wherein the microwave transmission circuit and the discharge chamber include an inner conductor and an outer conductor. (3) The plasma generating device according to claim 2, which has a circularly polarized wave generating device using means for generating a higher-order mode of a microwave electromagnetic field mode generated in a coaxial tube consisting of an inner conductor and an outer conductor. . (4) The plasma generating device according to claim 3, wherein the circularly polarized microwave magnetic field generating device is formed in a spiral shape of an inner conductor within the discharge chamber. (5) Claim 3 in which the microwave magnetic field circularly polarized wave generator comprises a conductor or dielectric material disposed within the discharge chamber.
Plasma generator as described in section. (6) The plasma generating device according to claim 3, wherein the circularly polarized microwave magnetic field generating device includes an inner conductor and an outer conductor that are eccentric.