JP2722070B2 - Plasma processing apparatus and plasma processing method - Google Patents

Description

[Description of the Invention] The present invention relates to a plasma processing apparatus. More specifically, the present invention relates to a plasma processing apparatus and a plasma processing method suitable for etching, sputtering, cleaning or ashing of an object to be processed using plasma, and film formation on a substrate.

[Description of Prior Art]

The plasma processing method is a method of converting a specific substance into plasma to generate strongly active radicals and ions, and bringing the radicals and ions into contact with the object to be etched and etching the object.
A processing method for performing processes such as deposition film formation, sputtering, cleaning, and ashing (ashing), and a plasma processing apparatus refers to an apparatus used for performing the plasma processing method.

Conventionally, such a plasma processing apparatus includes a plasma processing chamber formed of a vacuum vessel having a source gas inlet and an exhaust port, and an electromagnetic wave or the like that supplies energy for converting the source gas supplied to the plasma processing chamber into plasma. Supply device.

By the way, the plasma processing method relies on the strong activity of the above-mentioned radicals and ions. By appropriately selecting the density of the radicals and ions, the temperature of the object to be processed, and the like, various processes such as etching and deposition film formation are performed. Is a feature of the plasma processing method, and what is important in the plasma processing method is efficient generation of radicals and ions.

Conventionally, as a medium for applying plasma-forming energy,
Although high-frequency electromagnetic waves of about 13.56 MHz were used, it has recently been found that high-density plasma can be efficiently generated by using microwaves of about 2.45 GHz. , And several devices have been proposed for this purpose.

For example, amorphous silicon (hereinafter referred to as “A-Si”) as an element member used for a semiconductor device, an electrophotographic photoreceptor, an image input sensor, an imaging device, a photovoltaic element, other various electronic elements, an optical element, and the like. A method of forming a deposited film by a plasma CVD method using a microwave (hereinafter, referred to as “MW-PCVD method”) and an apparatus therefor have been proposed.

In this plasma processing technology, electrons are efficiently accelerated by an electric field generated by microwaves and a magnetic field generated by a magnetic field generator placed outside the discharge chamber, and high-density plasma generated by collision and ionization with neutral molecules is generated. The process is performed. In particular, if the magnitude of the magnetic field is determined such that the electron cyclotron frequency matches the microwave frequency, plasma can be generated efficiently. For the commonly used 2.45 GHz, the magnitude of the magnetic field is 875 Gauss.

Advantages of the plasma processing techniques, since the discharge pressure range is wide and 10 ^-4 to 10 Torr compared to high-frequency discharge type, 10 ^-3 to 10 ^-4
At a low pressure such as Torr, the mean free path of the ions is larger than the ion sheath width.For example, in an etching apparatus, ions are vertically incident on the sample, so that vertical etching or the like is possible, and at a pressure of 0.1 to 10 Torr, It is where a large amount of excited gas can be generated. In addition, since the energy of ions incident on the sample is as low as 20 eV, processing can be performed without damaging the sample.

However, in a conventional plasma processing apparatus,
Since the microwave is supplied to the discharge chamber through a microwave introduction window that is smaller than the cross section of the discharge chamber, after the plasma is generated, the microwave is absorbed by the plasma in the vicinity of the microwave introduction window and discharge occurs. There is a problem that uniform plasma is not generated in the room.

Incidentally, Japanese Patent Application Laid-Open No. 60-120525 discloses, as shown in FIG.
A microwave plasma processing apparatus is disclosed. In the figure,
701 is a discharge chamber, 702 is a processing room, 703 is a microwave introduction window, 7
04 is a rectangular waveguide, 705 is a plasma flow, 706 is a plasma extraction window, 707 is a sample, 708 is a sample mounting table, 709 is a sample table, 710
Is an exhaust system, 711 is a magnetic coil, 712 is a magnetic shield, 713
Denotes a first gas introduction system, 714 denotes a second gas introduction system, and 715 denotes a cooling water supply port and a drain port.

In order to generate plasma using the apparatus, an exhaust system 710 is required.
The discharge chamber 701 and the processing chamber 702 are evacuated to a high vacuum, and a gas is introduced from the first gas introduction system 713 and / or the second gas introduction system 714 to a pressure of 10 ^{-6 to 1} Torr, and a microwave source (shown in FIG. The microwave is introduced into the plasma discharge chamber 701 through the rectangular waveguide 704 and the microwave introduction window 703, and at the same time, the electron cyclotron is applied to at least a part of the discharge chamber by the magnetic coil 711 surrounding the discharge chamber 701. A magnetic field that satisfies the resonance condition is given. When a 2.45 GHz magnetron is used as the microwave source, the electron cyclotron resonance condition is a magnetic flux window of 875 G, and the discharge chamber 701 increases the microwave electric field strength and enhances the discharge efficiency by using a microwave cavity resonator. Is configured to satisfy the condition of For example, in the TE ₁₁₃ cylindrical cavity resonance mode, the inner rectangular dimension is 17 cm in diameter and 20 cm in height.
It is assumed that In order to satisfy the resonance mode, it is preferable that the microwave transmission window has a small size. By the way, in the conventional example, the waveguide for microwave introduction (usually
Use JIS standard WRJ-2 (inner diameter 109.22mm x 54.61mm)
Use the same size as the inner cross section. The plasma generated in the discharge chamber with the above configuration is supplied to the sample 707 through the plasma extraction window 706. When the plasma is generated, the introduced microwave is applied to the microwave introduction window 703 in the discharge chamber.
Is absorbed by the plasma in the vicinity of. This tendency increases as the plasma density increases,
In that case, the microwave does not propagate inside the discharge chamber. Therefore, uniform plasma cannot be generated in the discharge chamber, and uniform processing cannot be performed. In order to avoid this problem and perform uniform processing, the plasma extraction window 706 is narrowed, but in this case, the area to which the plasma is supplied is limited, and the plasma in the discharge chamber is not effective. There is a problem that is not used for.

On the other hand, in the field of microwave communication and radar completely different from the technical field, a slot (or slit) is formed in a flat plate.
Antenna with the antenna was developed (FJGoebels, and KCKe
lly, IRE Transactions on Antenna and Propagation, AP
−9, July, P342, 1961), and recently further development and improvement for satellite broadcasting reception (Naohisa Goto, Masaki Yamamoto,
IEICE Technical Report, A.P80-57, P43, 1980, or Hideo Sasawa, Yasuhide Oshima, Yoshio Sakurai, Makoto Ando, Naohisa Goto, IEICE Technical Report, A.P86-142, P29.198
6).

However, these flat slot antennas are mainly intended for application to microwave communication, radar, and the like, and are not intended for application to plasma generation at all.

[Object of the invention]

SUMMARY OF THE INVENTION The present invention solves the above-mentioned problems in the conventional plasma processing apparatus, and efficiently generates plasma and uses the generated plasma effectively for purposes such as etching, ashing, and film formation. It is a primary object of the present invention to provide a plasma processing apparatus and a plasma processing method that are provided.

Another object of the present invention is to allow microwaves to enter the microwave transmitting window from the outer peripheral portion of the microwave transmitting window so that the microwaves are radiated into the discharge space of the vacuum vessel, thereby allowing the discharge to occur. Plasma processing in which plasma is generated efficiently and in a uniform distribution state in a space, and the generated plasma enables uniform etching or ashing of a sample and uniform film formation on a substrate. An object of the present invention is to provide an apparatus and a plasma processing method.

[Structure and effect of the invention]

The present invention solves the above-mentioned problems in the conventional plasma processing technology and achieves the above object.

The present invention includes a plasma processing apparatus and a plasma processing method configured as described below.

The plasma processing apparatus of the present invention includes a vacuum vessel having a discharge space, a means for supplying a processing gas into the vacuum vessel, and a microwave introduction for introducing a microwave for generating plasma in the vacuum vessel. Means, and a plasma processing apparatus comprising: a sample holder for holding a sample to be processed in the vacuum vessel; wherein the microwave introducing means includes a surface to be processed of the sample to be processed disposed in the vacuum vessel. A circular plate-shaped microwave radiating member having a spiral or a slit arranged on a concentric circle for radiating the microwave into the vacuum vessel, and the circular plate-shaped microwave A microwave coaxial tube having a coaxial inner conductor and a coaxial outer conductor provided toward the center of the radiation member, and propagates in a radial direction of the circular plate-shaped microwave radiation member. The microwave radiating from said slit to generate plasma of the process gas into the vacuum chamber, is characterized in.

The plasma processing method according to the present invention includes a vacuum vessel having a discharge space, a means for supplying a processing gas into the vacuum vessel, and a microwave introduction for introducing a microwave for generating plasma in the vacuum vessel. Means, and a plasma processing method using a plasma processing apparatus comprising a sample holder for holding a sample to be processed in the vacuum vessel, wherein the surface of the sample to be processed is treated by the vacuum vessel. Arranged on the sample holder so as to face a circular plate-shaped microwave radiating member having a spiral or a slit arranged on a concentric circle for radiating into the sample holder, and disposing the microwave on the circular plate-shaped microwave From the coaxial waveguide for microwave propagation having the coaxial inner conductor and the outer coaxial conductor provided toward the center of the radiation member, the coaxial waveguide is directed toward the center of the circular plate-shaped microwave radiation member. The microwave is radiated from the slit while the introduced microwave is propagated in the radial direction of the circular plate-shaped microwave radiating member to generate plasma of the processing gas in the vacuum vessel, thereby plasma-treating the sample to be processed. It is characterized by processing.

The plasma processing apparatus of the present invention having the above-described configuration will be described below in detail with reference to embodiments of the drawings.

FIG. 1 is a sectional view of the most typical plasma processing apparatus of the present invention. In FIG. 1, reference numeral 101 denotes a vacuum container for keeping a processing unit at a vacuum, 102 denotes a gas inlet for introducing a processing gas into the vacuum container, 103 denotes a microwave launcher for emitting microwaves, and 107 denotes plasma. Is a discharge chamber, 104 is a mask that radiates microwaves to the discharge chamber 107, a slit is formed in a conductive plate, 105 is a dielectric,
The microwave transmission window is made of, for example, quartz, alumina, boron nitride, forsterite, or the like, and vacuum seals between the inside of the microwave launcher 103 and the discharge chamber 107. Reference numerals 106a and 106b denote a coaxial outer conductor and a coaxial inner conductor for supplying microwaves to the microwave launcher 103, respectively. 108 is a sample to be processed, 109 is a sample holder, 110 is a vacuum exhaust system for maintaining the processing pressure in the discharge chamber, 111 is an air-core coil for generating a magnetic field in the discharge chamber, 112
Is a microwave propagation path, 113 is a taper for suppressing microwave reflection, 114 is a conductor plate for forming a two-layer structure, and 115 is microwave transmission insulation for avoiding direct contact between the conductor plate 114 and plasma. Reference numeral 116 denotes a surface for vacuum-sealing the microwave window.

FIG. 2 shows an example of a conductor flat plate 104 having slits used in the present invention. Here, reference numeral 201 denotes a spiral slit having a width S and an interval d.

Next, in the above configuration, the microwave (usually 2.45 GHz) generated by the microwave oscillator is supplied by a waveguide to an isolator that absorbs the microwave returning to the microwave oscillator, and further matched with the microwave launcher 103. To a coaxial converter with a tuner to take
Here, the waveguide is converted into a coaxial waveguide and supplied to the center of the microwave launcher 103. On the other hand, processing gas, for example, Cl ₂ for etching of Si substrate, S for film deposition of amorphous Si
For iH ₄ and resist ashing, O ₂ is supplied from the gas inlet 102. The microwave enters the microwave launcher from the upper layer to the lower layer along the propagation path 112.

Since the lower layer is a microwave window 105, the wavelength of the microwave entering the window is given by the relative permittivity of the window material as Er. become. Therefore, the length of the slit or slot formed in the conductive flat plate 104 is determined by the wavelength, and the slit or slot length can be reduced by selecting the material of the window. Quartz, alumina, false light, boron nitride, which have low microwave absorption as window materials,
The dielectric constant greater (Zr, Sn) TiO systems, BaO-TiO ₃ system, are suitable ceramic composite perovskite. The size is appropriately determined according to the purpose of use of the apparatus, the scale of the apparatus, and the like.

By the way, the microwave transmitting window is in contact with the inner wall surface of the microwave launcher 103 at a portion 116, and it is necessary to perform vacuum sealing on the contact portion. For this,
The contact portion is bonded with an appropriate microwave-permeable adhesive and sealed in a vacuum. With respect to the adhesive, the atmospheric pressure acts on the contact portion in a direction to hold down the portion at 116, so that the adhesive force may not be so large. A preferable example of such an adhesive is a silicone resin adhesive.

The microwave propagates through the microwave transmitting window between the conductive plate 104 and the conductive plate 114 having the slit shown in FIG. 2, and is gradually radiated from the slit 201. After passing through the insulation and reaching the discharge chamber 107, a microwave electric field is created therein, and plasma is efficiently generated by the magnetron effect of the electric field and the magnetic field generated by the air-core coil 111. Also, make the magnitude of the magnetic field the same as the electron cyclotron frequency and microwave frequency (2.45 GHz
At 875 Gauss for z), the electrons are resonantly accelerated and plasma is generated more efficiently.

At this time, an insulator of 115 is attached to prevent the plasma from directly contacting the conductive flat plate to prevent the metal from being sputtered and the sample from being contaminated by the metal. As the material of the insulator, a material that absorbs less microwaves and does not become a source of contamination is selected.
For example, quartz is used for Si and SiO etching and amorphous Si is deposited, and alumina is used for alumina etching. The microwave radiation distribution that determines the spatial distribution of the processing can be controlled by the width S and the interval d of the slit 201 formed in the conductive flat plate 104.

For example, if the intensity of the microwave at the center is high, the slit interval d is increased at the center and reduced at the periphery. The width of the slit can be similarly set. Note that the shape of the slit described here is not limited to a spiral, and the same effect can be obtained by an arbitrary shape such as a concentric circle and a shape having a number of cross slots.

After the plasma is generated, the microwave is absorbed in the discharge space near the microwave window as described above. However, in the generated plasma, the direction of the magnetic flux density of the magnetic field generated by the air-core coil 111 is perpendicular to the surface of the sample 108, and the plasma is efficiently diffused along the magnetic field in a direction perpendicular to the sample surface without much diffusion. The surface of 108 is reached and the desired treatment is performed.

Further, by moving the sample holder 109 away from the strongest magnetic field to a position where it is about 1/2 to 1/10, the divergence and acceleration of the plasma by the magnetic field can be obtained, and the processing can be promoted.

In the aforementioned embodiment, as shown in FIG.
Around the outside of the tube, a dielectric ring made of, for example, alumina, quartz, forsterite, boron nitride, Teflon, polystyrene, etc. (Where ε _r is the relative dielectric constant of the dielectric), the wavelength is shortened, and it is easy to enter the lower layer from the upper layer. When the microwave transmission window 105 is made of the same material, the same structure may be used.

As the next embodiment, an apparatus for applying high-frequency power to the sample holder 109 is shown in FIG. In FIG. 4, 412 is an insulator for electrically insulating the sample holder, 413 is a high frequency power supply for supplying high frequency power to the sample holder, and 414 is a capacitor for floating the holder DC. It is. The same reference numerals as in FIG. 1 denote the same parts as those in FIG.

Explaining the operation of this device, plasma is generated in the discharge chamber 107 by microwaves as in the above-described embodiment. At the same time, when high-frequency power is applied to the sample holder, the sample holder is negatively biased because it is DC-floating by the capacitor 414, and the ions are accelerated toward the sample 108 by the bias voltage, thereby promoting the processing by the ions. You. Since the ion energy is determined by the bias voltage and the bias voltage is determined by the high frequency power, the ion energy can be controlled by the high frequency power.

In the case of etching, for example, in the etching of SiO _{2 which} requires a certain amount of ion energy, the ion energy is controlled so that there is no damage due to ion collision, and an appropriate etching rate can be obtained. In the deposition of a SiO ₂ film, the energy of ions is controlled, and a film is deposited while simultaneously performing appropriate etching by ion bombardment, so that a flat film can be formed without unevenness on the film.

Regarding the frequency of the high frequency used, it is 2-3 MHz or more,
The energy of ions can be controlled by bias voltage, and industrial high frequency of 13.56 MHz is usually used. On the other hand, at a high frequency of 2 to 3 MHz or less, the energy of ions cannot be controlled by the bias voltage. However, since the ions are directly accelerated by the high-frequency electric field, the energy of the ions can be controlled similarly. Commonly used frequencies are in the range of 100 KHz to 500 KHz. In this case, the high frequency may be applied to the opposed microwave launcher 103 instead of the sample holder. This is because the slit interval is usually 100 cm or less and the slit width S is 1 cm or less.
z) It can be regarded as a flat plate. FIG. 5 shows an embodiment. In FIG. 5, reference numeral 515 denotes a device for blocking a high frequency wave from going to a coaxial converter with a tuner. For example, a device having a choke structure generally used in a microwave circuit may be used. Insulators for electrical insulation, and those having the same reference numerals as in FIGS. 1 and 4 are the same as those in FIGS. 1 and 4. Next, the operation of this apparatus will be described. As in the embodiment shown in FIG. 4, plasma is generated in the discharge chamber 107 by microwaves, and a high frequency power supply 413 applies a high frequency to the entire microwave launcher.
A high-frequency electric field is generated between the 104-plasma-sample holder (or sample), and the electric field accelerates ions, so that etching, ashing, film formation, and the like can be performed efficiently.

In the two examples of simultaneously applying the high frequency described above, since the conductor flat plate 104 and the sample holder 109 act as counter electrodes of the parallel plate type reaction apparatus, simply apply a high frequency electric field to one side,
Unlike the case without the opposing flat plate electrode, the mask-plasma-
A uniform high-frequency electric field is generated between the sample holders, and uniform etching, ashing, film formation, and the like can be performed.

As a next embodiment, FIG. 6 shows an apparatus for extracting ions from a plasma generated in a discharge chamber 107 by an electrode group and irradiating a sample 108 with the ions for processing.

In FIG. 6, reference numeral 617 denotes an insulating inner container that transmits microwaves such as quartz, alumina, boron nitride, and forsterite for insulating the plasma generated in the discharge chamber from the vacuum vessel, and 618, 619, and 620 open many holes to each other. Ion extraction electrode with holes optically aligned, 62
1,622 is a DC power supply for applying a DC voltage to the extraction electrodes 618,619, 623 is a processing chamber, and 102 'is a gas inlet provided in the processing chamber.

The operation of the device shown in FIG.
The microwaves radiated from the slits or slots pass through the insulating inner container 617 and are supplied to the discharge chamber 107.

Next, when a processing gas, for example, a SiN film is deposited on a sample Si substrate, an N ₂ gas is introduced from 102 and a SiH ₄ gas is introduced from 102 ′. Plasma is generated in the discharge chamber 107 by the same operation as the embodiment shown in FIG. 1, and the plasma is diffused along the lines of magnetic force to reach the ion extraction electrode 618. The ions (mainly N ⁺ and N ₂ ⁺ ) in the plasma are
Get energy dependent on the voltage applied by 22,
The spread of ions is controlled by the voltage applied by the electrode 619, and the sample holder 1 installed in the processing chamber 623 is controlled.
The sample 108 placed on 09 is irradiated and combined with SiH ₄ to deposit a SiN film. The number of extraction electrodes need not be limited to the three-plate configuration shown in FIG. 5, and the same effect can be obtained with a one- or two-plate configuration.

The distribution of ions extracted from the plasma chamber 107 largely depends on the distribution of plasma in the plasma chamber. The uniform flat plate 104 with slits generates uniform plasma by emitting microwaves from the conductive flat plate 104 with slits. Can be obtained. By etching with this ion beam under a pressure of the order of 10 ^-4 Torr, the ion beam having a uniform direction reaches the sample, and the etching proceeds in the direction in which ions travel, so that anisotropic etching becomes possible.

Example of Etching A case will be described in which SiO ₂ is etched by using the Si substrate covered with an SiO ₂ film as the sample 108 in the apparatus shown in FIG.

First, the Si substrate is placed on the sample holder 109. Next, the inside of the vacuum vessel 101 is degassed to 2 × 10 ⁻⁶ Torr or less by the vacuum evacuation system 110. Next, an etching gas CHF ₃ is introduced from the gas inlet 102, the conductance of a valve (not shown) of the vacuum exhaust system is adjusted, and the internal pressure is set to 1 × 10 ⁻³ Torr. Next, energize the microwave oscillator, oscillate microwaves of 2.45 GHz, 300 W, adjust the tuner of the coaxial converter with tuner, and adjust the reflected power to 30 W or less. The microwave is radiated to generate plasma in the discharge space 107. The Si substrate is etched by ions and radicals in the plasma.
After etching for a predetermined time, the substrate was taken out and the amount of etching was measured.

Example of forming a deposited film of SiN In the apparatus shown in FIG.
The case where a deposited film is formed will be described.

First, the Si substrate is placed on the sample holder 109. Next, the inside of the vacuum vessel 101 is evacuated to an internal pressure of 2 × 10 ⁻⁶ Torr or less by the vacuum exhaust system 110. Next, 30 scc of SiH ₄ gas from gas inlet 102
m, N ₂ gas 10 sccm was introduced, the conductance of a vacuum exhaust system valve (not shown) was adjusted, and the internal pressure was set to 1 × 10 ^-2 Torr.
Set to. Next, energize the microwave oscillator and set it to 2.45GHz,
Oscillate a microwave of 500 W, adjust the tuner of the coaxial converter with a tuner, reduce the reflected power to 30 W or less, radiate the microwave from the slit provided in the conductor plate 104, and generate plasma in the discharge space 107. generate. This plasma is exposed to a Si substrate, and SiN is deposited for a predetermined time to obtain a film having a desired thickness. Thus obtained. When this was subjected to various tests and examined, a dense, uniform and homogeneous film was obtained.

[Summary of effects of the invention]

As described above, according to the plasma processing apparatus of the present invention in which microwaves are supplied using a conductive plate having a slit (or slot), the uniformity of the plasma processing is improved, and only the processing unit is provided. Since microwaves can be supplied, microwaves can be supplied efficiently.

Further, vacuum sealing at the oblique outer peripheral portion of the microwave transmitting window simplifies the structure of the vacuum sealing portion, and has an effect of improving the reliability of the bonding portion.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of a plasma processing apparatus embodying the present invention, FIG. 2 is a plan view of a conductor plate having a spiral slit, and FIG. It is sectional drawing of the microwave launcher part which provided the ring-shaped dielectric in the incidence part. FIG. 4 is a cross-sectional view of an apparatus for applying high-frequency power to the sample holder, FIG. 5 is a cross-sectional view of an apparatus for applying high-frequency power to the microwave launcher, and FIG. It is sectional drawing of the apparatus which extracts and processes an ion. FIG. 7 is a sectional view of a conventional microwave plasma processing apparatus. In FIG. 1, 101: vacuum vessel, 102: gas inlet, 10
3 ... microwave launcher, 104 ... conductor plate with slit or slot, 105 ... microwave transmission window, 106 a ... coaxial outer conductor, 106 b ... coaxial inner conductor, 107 ... discharge chamber, 108 ... sample,
109: sample holder, 110: vacuum evacuation system, 111: air-core coil, 112: microwave propagation path, 113: taper, 114: conductor plate, 115: insulator, 116: surface for vacuum sealing the microwave window. In FIG. 2, reference numeral 201 denotes a spiral slit. In FIG. 3, 117... A ring-shaped dielectric. In FIG. 4, 412 is an insulator, 413 is a high frequency power supply, 414
... capacitors. In FIG. 5, reference numeral 515 denotes a high frequency blocking unit, and 516 denotes an insulator. In FIG. 6, 617 ... microwave transmitting inner container, 618,61
9,620… Ion extraction electrode, 621,622… DC power supply, 62
3… Processing room. 7, 701: plasma discharge chamber; 702: processing chamber;
703: microwave introduction window, 704: rectangular waveguide, 705: plasma flow, 706: plasma extraction window, 707: sample, 708: sample mounting table, 709: sample table, 710: exhaust system, 711: magnetic coil, 712… magnetic shield, 713… first gas introduction system, 714…
2nd gas introduction system, 715: Cooling water inlet and outlet.

Claims (5)

(57) [Claims] 1. A vacuum vessel having a discharge space, a means for supplying a processing gas into the vacuum vessel, a microwave introduction means for introducing a microwave for generating plasma in the vacuum vessel, In a plasma processing apparatus including a sample holder for holding a sample to be processed in the vacuum container, the microwave introduction unit is arranged in parallel with a surface to be processed of the sample to be processed disposed in the vacuum container. A circular plate-like microwave radiating member having a spiral or a slit arranged on a concentric circle for radiating the microwave into the vacuum container, and a circular plate-like microwave radiating member. A coaxial waveguide for microwave propagation having a coaxial inner conductor and a coaxial outer conductor provided toward the center, the microwave propagating in the radial direction of the circular plate-shaped microwave radiating member; The plasma processing apparatus characterized by radiating from lit to generate a plasma of the processing gas into the vacuum vessel. 2. The plasma processing apparatus according to claim 1, wherein the circular plate-shaped microwave radiating member has a large number of cross slits. 3. The plasma processing apparatus for performing etching, ashing, or film formation on the sample to be processed, wherein a high-frequency wave is provided between the sample to be processed and the circular plate-shaped microwave radiating member. The plasma processing apparatus according to claim 1, further comprising a high-frequency power supply for generating an electric field. 4. The method according to claim 1, wherein a microwave transmitting insulating plate is provided on the side of the sample to be processed of the circular plate-shaped microwave radiating member, and a dielectric is provided on a side opposite to the sample to be processed. The plasma processing apparatus as described in the above. 5. A vacuum vessel having a discharge space, means for supplying a processing gas into the vacuum vessel, microwave introduction means for introducing a microwave for generating plasma in the vacuum vessel, In a plasma processing method using a plasma processing apparatus including a sample holder for holding a sample to be processed in the vacuum container, the surface of the sample to be processed is irradiated with the microwave into the vacuum container. It is arranged on the sample holder so as to face a circular plate-like microwave radiating member having a spiral or a slit arranged on a concentric circle for performing the microwave on the circular plate-like microwave radiating member. A microphone introduced from a coaxial waveguide for microwave propagation having a coaxial inner conductor and a coaxial outer conductor provided toward the center toward the center of the circular plate-shaped microwave radiating member. Radiating microwaves from the slits while propagating waves in the radial direction of the circular plate-shaped microwave radiating member, generating plasma of the processing gas in the vacuum vessel, and plasma-treating the sample to be processed. A plasma processing method characterized by the above-mentioned.