Microwave plasma generator, microwave plasma processing apparatus, and microwave plasma processing method

Abstract

To provide a microwave plasma generation device which increases an amount of a microwave transmitted into a discharge space in a cylindrical container and improves microwave energy utilization efficiency in the microwave plasma generation device which introduces the microwave to a propagation region provided in the outer periphery of the cylindrical container made of a dielectric body and generates plasma in the cylindrical container, and a microwave plasma processing apparatus using the microwave plasma generation device.SOLUTION: A microwave plasma generation device comprises: a cylindrical container which is made of a dielectric body; a cylindrical chamber which is arranged so as to cover the cylindrical container on the outer side of the cylindrical container; a gas supply port which supplies gas into the cylindrical container; and a microwave introduction port which is provided on the lateral side of the cylindrical chamber, and generates plasma along the inner surface of the cylindrical container. A dielectric material is filled in a space between the cylindrical container and the cylindrical chamber.SELECTED DRAWING: Figure 1(a)

Description

[Technical Field]

[0001] The present invention relates to a microwave plasma generator that generates plasma using microwaves, a microwave plasma processing apparatus using the same, and a method for performing microwave plasma processing using the microwave plasma processing apparatus. [Background technology]

[0002] In semiconductor manufacturing processes, plasma treatment is widely used for etching and film deposition of semiconductor substrates. Among plasma treatment devices that perform such plasma treatment, microwave plasma treatment devices, which can uniformly form high-density, low-electron-temperature plasma, are attracting attention.

[0003] Microwave plasma processing equipment has a microwave-excited plasma source that excites the plasma with microwaves having wavelengths of several hundred MHz to several tens of GHz. Because it has a lower plasma potential compared to high-frequency plasma sources, it is widely used for damage-free resist ashing and anisotropic etching with applied bias voltage.

[0004] Patent Document 1 (Japanese Patent Application Publication No. 2003-38951) discloses a plasma generator comprising a vacuum chamber, a waveguide for guiding microwaves, a cylindrical microwave introduction section made of a dielectric for introducing microwaves guided by the waveguide into the vacuum chamber, and a discharge space surrounded by the microwave introduction section, wherein the waveguide is provided so as to surround the cylindrical microwave introduction section, and the microwaves introduced into the discharge space via the microwave introduction section generate a plasma of a reactive gas supplied into the discharge space.

[0005] However, in the case of a plasma generator with the configuration described in Patent Document 1, there is a problem in that the transmission of microwaves into the discharge space is reduced due to the cylindrical microwave introduction section made of a dielectric placed between the microwave waveguide and the plasma generation region in the discharge space, and a configuration that can utilize microwave energy more efficiently is desired.

[0006] Patent Document 2 (JP 2008-177131 A) discloses a plasma generator comprising an introduction waveguide for introducing microwaves, a dielectric (discharge tube) for separating a depressurized space from an atmospheric pressure space, and a plasma expansion member having a dielectric constant lower than that of the dielectric, wherein microwaves are introduced into the dielectric from the atmospheric pressure space side to generate plasma on the depressurized space side. Patent Document 2 states that by providing a member with a lower dielectric constant than the discharge tube (plasma expansion member), the propagation range of microwaves can be expanded, and the plasma generation range can also be expanded, thereby suppressing concentrated plasma generation.

[0007] However, the plasma generator described in Patent Document 2 has a microwave passage with a passage width W [a value greater than half a microwave wavelength (λ / 2) and less than one wavelength (λ)] between the plasma expansion member and the introduction waveguide, and a gap is provided between the inner surface of the plasma expansion member and the outer surface of the discharge tube. As a result, problems arise such as reduced transmission of microwaves from this microwave passage (air) to the plasma expansion member and reduced transmission of microwaves from the gap to the discharge tube, so there is room for improvement in terms of energy efficiency. [Prior art documents] [Patent Documents]

[0008] [Patent Document 1] Japanese Patent Publication No. 2003-38951 [Patent Document 2] Japanese Patent Publication No. 2008-177131 [Overview of the project]

Problems to be Solved by the Invention

[0009] Therefore, an object of the present invention is to provide a microwave plasma generator that introduces microwaves into a propagation region provided on the outer periphery of a cylindrical container made of a dielectric and generates plasma inside the cylindrical container, and that increases the amount of microwaves transmitted into the discharge space inside the cylindrical container and improves the energy utilization efficiency of the microwaves, a microwave plasma processing apparatus using the microwave plasma generator, and a method for performing microwave plasma processing using the microwave plasma processing apparatus.

Means for Solving the Problems

[0010] In view of the above object, the present inventors have found that by filling the microwave propagation region on the outer periphery of a cylindrical container made of a dielectric with a dielectric material having a different dielectric constant from that of the cylindrical container, the amount of microwaves transmitted into the discharge space inside the cylindrical container increases, and have arrived at the present invention.

[0011] That is, the microwave plasma generator of the present invention comprises a cylindrical container made of a dielectric, a cylindrical chamber disposed outside the cylindrical container so as to cover the cylindrical container, a gas supply port for supplying gas into the cylindrical container, and a microwave inlet provided on a side of the cylindrical chamber, and is a microwave plasma generator for generating plasma along the inner surface of the cylindrical container in characterized in that a dielectric material is filled between the cylindrical container and the cylindrical chamber. Preferably, the dielectric material includes a dielectric material having a dielectric constant different from that of the cylindrical container.

[0012]

[0013] ​The dielectric material preferably includes a dielectric material having a dielectric constant higher than that of the cylindrical container.

[0014] The dielectric material is composed of two or more dielectric materials provided so as to cover the cylindrical container, and preferably, the dielectric material closest to the cylindrical container has a dielectric constant higher than that of the cylindrical container.

[0015] Preferably, an anti-reflection structure for microwaves is provided at the microwave inlet.

[0016] The cylindrical container preferably has an inner diameter of 10 to 300 mm and a thickness of 5 to 100 mm, more preferably an inner diameter of 20 to 100 mm and a thickness of 10 to 50 mm, and most preferably an inner diameter of 30 to 80 mm and a thickness of 15 to 30 mm.

[0017] The microwave plasma processing apparatus of the present invention is characterized by comprising the microwave plasma generator and a sample processing chamber connected to the microwave plasma generator and arranged so that the plasma generated by the microwave plasma generator is supplied.

[0018] In the microwave plasma processing apparatus, The sample processing chamber preferably includes a holding table for holding the workpiece so that the plasma is irradiated onto the workpiece, and a gas exhaust port for exhausting the supplied gas and the gas containing the processed plasma.

[0019] The microwave plasma processing method of the present invention is a method for processing the workpiece using the microwave plasma processing apparatus, Gas is supplied from the gas supply port provided in the cylindrical container of the microwave plasma generator, microwaves are introduced from the microwave inlet provided on the side of the cylindrical chamber, and plasma is generated inside the cylindrical container. Plasma is supplied to the sample processing chamber connected to the cylindrical container, and while exhausting the supplied gas and the gas containing the processed plasma from the gas exhaust port provided in the sample processing chamber, the object to be processed held on the holding table in the sample processing chamber is irradiated with plasma to perform processing of the object to be processed.

[0020] In the microwave plasma processing method, the cylindrical container Inside is 1.3×10 Equivalent to Pa preferably maintained at a pressure of 10 Torr or less, 1.3×10 -1 Pa~1.3×10 3 Equivalent to Pa more preferably maintained at a pressure of 1 mTorr to 10 Torr, 1.3 Pa ~ 1.3 × 10 2 Equivalent to Pa most preferably maintained at a pressure of 10 mTorr to 1 Torr.

[0021] In the microwave plasma processing method, the flow rate of the gas supplied into the cylindrical container is 1.7×10 -5 ~1.7×10 -1 Pa·m 3 Equivalent to / s preferably 0.01 to 100 sccm, 1.7×10 -4 ~1.7×10 -2 Pa·m 3 Equivalent to / s more preferably 0.1 to 10 sccm, 8.5×10 -4 <00001x40> -3 Pa·m 3 Equivalent to / s most preferably 0.5 to 5 sccm.

[0022] In the microwave plasma processing method, The output of the microwaves supplied is 10 to 10,000 W / cm². 2 Preferably, the power is 100-1000 W / cm². 2 It is more preferable that the temperature is 200-700 W / cm². 2 This is the most preferable outcome. [Effects of the Invention]

[0023] The microwave plasma generator of the present invention can increase the amount of microwaves transmitted into the discharge space inside the cylindrical container, thereby improving the energy utilization efficiency of microwaves. Furthermore, by placing a dielectric material with a high dielectric constant on the outside of the cylindrical container, the effect of substantially shortening the wavelength of microwaves is achieved, allowing the microwave plasma generator to be made smaller. For this reason, it is particularly suitable for compact microwave plasma processing equipment and processing methods using the same. [Brief explanation of the drawing]

[0024] [Figure 1(a)] This is a schematic cross-sectional view showing an example of the microwave plasma processing apparatus of the present invention. [Figure 1(b)] This is a cross-sectional view AA of Figure 1(a). [Figure 2(a)] This is a schematic cross-sectional view showing an example of a configuration using two types of dielectric materials. [Figure 2(b)] This is a schematic cross-sectional view showing another example of a configuration using two types of dielectric materials. [Figure 2(c)] This is a schematic cross-sectional view showing yet another example of a configuration using two types of dielectric materials. [Modes for carrying out the invention]

[0025] [1] Microwave plasma processing equipment Figures 1(a) and 1(b) show an example of the microwave plasma generator 100 of the present invention. The microwave plasma processing apparatus 100 of the present invention comprises a microwave plasma generator 101 that generates plasma using microwaves, and a sample processing chamber 102 connected to the microwave plasma generator 101 and arranged to receive the plasma generated by the microwave plasma generator 101. The microwave plasma generator 101 comprises a cylindrical container 103 made of a dielectric material, a cylindrical chamber 109 positioned outside the cylindrical container 103 to cover it, a gas supply port 104 for supplying gas into the cylindrical container 103, and a microwave inlet 105 provided on the side of the cylindrical chamber 109, and is a microwave plasma generator 101 for generating plasma along the inner surface of the cylindrical container 103, characterized in that a dielectric material 110 is filled between the cylindrical container 103 and the cylindrical chamber 109. Preferably, the dielectric material 110 has a dielectric constant different from that of the cylindrical container 103, and more preferably has a portion with a higher dielectric constant than the cylindrical chamber. In addition to filling the entire material with a high dielectric constant, there may be portions with a low dielectric constant on the outside or inside.

[0026] (1) Microwave plasma generator The microwave plasma generator 101 of the present invention is a device that generates plasma using microwaves. When gas G (for example, hydrogen gas) is supplied from a gas supply port 104 to a cylindrical container 103 kept under reduced pressure, microwaves M are introduced from a microwave inlet 105 provided on the side of a cylindrical chamber 109. The microwaves generate standing waves using the surface of the cylindrical container 103 as a transmission path, and plasma of gas G is generated inside the cylindrical container 103 by the microwaves that have passed through the cylindrical container 103. At this time, by filling the gap between the cylindrical container 103 and the cylindrical chamber 109 with a dielectric material 110, reflection of microwaves at the interface between the cylindrical container 103 and the air is suppressed, and microwaves are sufficiently transmitted to the inside of the cylindrical container 103, improving plasma generation efficiency and, as a result, increasing processing efficiency.

[0027] The dielectric material 110 filling the gap between the cylindrical container 103 and the cylindrical chamber 109 may be the same material as the material constituting the cylindrical container 103, i.e., a material with the same dielectric constant, or it may be a material with a different dielectric constant. In particular, if a material with a higher dielectric constant than the dielectric constant of the cylindrical container 103 is used as the dielectric material 110, the effect of improving processing efficiency will be greater due to effects such as reduction of the device dimensions. The dielectric constant of the dielectric material 110 is preferably 1 or more than the dielectric constant of the cylindrical container 103, and more preferably 1.1 to 10 times. It is also acceptable to use a high dielectric constant material in only a part of the device. This will also result in the effect of reducing the device dimensions.

[0028] The dielectric material 110 filling the gap between the cylindrical container 103 and the cylindrical chamber 109 may be of one type or composed of two or more types of dielectric materials. For example, when composed of two types of dielectric materials, the two types of dielectric materials 110a and 110b may be divided radially into layers (i.e., concentrically with the cylindrical container) and arranged as shown in Figure 2(a), or divided circumferentially and arranged alternately as shown in Figure 2(b), or a combination of radial layering and circumferential divisions may be used to create a mosaic-like arrangement as shown in Figure 2(c). The width of each dielectric material when divided may be selected as appropriate. The same applies when composed of three or more types of dielectric materials.

[0029] The dielectric material 110 filling the gap between the cylindrical container 103 and the cylindrical chamber 109 may be constructed by arranging materials with different dielectric constants in the axial direction. For example, a dielectric material with an axial length (height) of 90 mm may have a dielectric constant of 3 for a length of 30 mm at one end (upper part) and a length of 30 mm at the other end (lower part), and a dielectric constant of 6 for a length of 30 mm in the central part. With such a configuration, plasma will concentrate in the central part, and a high effect can be expected.

[0030] When two or more dielectric materials 110a and 110b are divided and arranged radially in layers (i.e., concentrically with the cylindrical container), it is preferable that the dielectric material 110a closest to the cylindrical container 103 has a higher dielectric constant than the dielectric constant of the cylindrical container 103. In this case, the dielectric constant of the dielectric material 110b furthest from the cylindrical container 103 may be higher or lower than that of the cylindrical container 103, and may also be higher or lower than that of the dielectric material 110a closest to the cylindrical container 103. It is preferable that the volume average of the two dielectric materials is greater than 1.

[0031] The cylindrical container 103 is preferably made of a material with excellent corrosion resistance to plasma, such as quartz (relative permittivity: 3.9), alumina (relative permittivity: 9.0), boron nitride (relative permittivity: 4), or aluminum nitride (relative permittivity: 8.5).

[0032] Examples of dielectric materials 110 include mica (6-8), acrylic resin (2.7-4.5), urethane (6.5-7.1), glass (3.7-10.0), glass-epoxy laminate (4.5-5.2), trifluoroethylene resin (2.4-2.5), silicone resin (3.5-5), silicone rubber (3.0-3.5), styrene-butadiene rubber (3.0-7.0), quartz glass (3.5-4.0), styrene resin (2.3-3.4), tetrafluoroethylene resin (2.0), nylon (3.5-5.0), neoprene (6.0-9.0), paraffin (1.9-2.5), fluororesin (4.0-8.0), unsaturated polyester resin (2.8-5.2), polyamide (2.5-2.6), polyester resin (2.8-8.1), Materials such as polyethylene (2.3-2.4), polybutylene (2.2-2.3), polypropylene (2.0-2.3), phenolic resin (3.0-12.0), polyacetal resin (3.6-3.7), polyurethane (5.0-5.3), polyethylene terephthalate (2.9-3.0), polycarbonate (2.9-3.0), polystyrene (2.4-2.6), polystyrene (2.0-2.6), polyvinyl alcohol (2.0), polybutylene resin (2.25), polypropylene resin (2.2-2.6), polymethyl acrylate (4.0), melamine resin (4.7-10.2), methacrylic resin (2.2-3.2), wood (2.0-6.0), and petrolatum (2.2-2.9) can be used. The numbers in parentheses after each dielectric material indicate the relative permittivity. The state of the dielectric material 110 is not particularly limited; for example, it may be solid, liquid, or bead-like.

[0033] It is preferable to position the dielectric material 110 in close contact with the cylindrical container 103 and the cylindrical chamber 109 so that no gaps are formed between the dielectric material 110 and the cylindrical container 103 and the cylindrical chamber 109. If gaps are formed between the dielectric material 110 and the cylindrical container 103 and the cylindrical chamber 109, an interface is formed between the air and the dielectric material 110, and microwave reflection occurs at this interface, reducing the amount of microwaves transmitted to the inside of the cylindrical container 103.

[0034] The cylindrical container preferably has an inner diameter of 10 to 300 mm and a thickness of 5 to 100 mm, more preferably an inner diameter of 20 to 100 mm and a thickness of 10 to 50 mm, and most preferably an inner diameter of 30 to 80 mm and a thickness of 15 to 30 mm. The present invention is thus suitable for relatively small microwave plasma generators.

[0035] In order to prevent a decrease in microwave utilization efficiency due to microwaves being irradiated almost perpendicularly onto the dielectric material 110 and the cylindrical container 103 and reflected, it is preferable that the microwave inlet 105 of the microwave plasma generator 101 is provided with a microwave anti-reflection structure 111 at the portion connected to the cylindrical chamber 109. As the anti-reflection structure 111, for example, a structure having a so-called moth-eye structure, in which many nanoscale fine protrusions are arranged at regular intervals, can be used. Alternatively, a layer of low dielectric constant material may be provided.

[0036] (2) Sample processing room The sample processing chamber 102 is connected to the microwave plasma generator 101 and is arranged so that the plasma generated by the microwave plasma generator 101 is supplied to it. The sample processing chamber 102 includes a holding stand 107 for holding the object to be processed 106 so that the plasma generated by the microwave plasma generator 101 irradiates the object to be processed 106, and a gas exhaust port 108 for exhausting the supplied gas and the gas containing the processed plasma. The holding stand 107 is rotatable about a predetermined rotation axis R, and it is preferable that the rotation axis R and the central axis C of the cylindrical container 103 are not on the same straight line. Alternatively, the rotation axis R and the central axis C of the cylindrical container 103 may be arranged at a predetermined angle. It is preferable that the holding stand 107 is equipped with a temperature control function.

[0037] The location of the gas exhaust port 108 is not particularly limited, but it is preferably downstream of the holding base 107, that is, behind the holding base 107 as viewed from the microwave plasma generator 101. In particular, it is preferable to provide it on the side of the holding base 107 opposite to the side where the workpiece 106 is placed.

[0038] [2] Microwave plasma processing method The microwave plasma processing method of the present invention is performed using a microwave plasma processing apparatus 100 (for example, the apparatus shown in Figures 1(a) and 1(b)) which comprises the aforementioned microwave plasma generator 101 and a sample processing chamber 102 connected thereto. Specifically, the microwave plasma processing method of the present invention is characterized by supplying gas G from a gas supply port 104 provided in a cylindrical container 103 of the microwave plasma generator 101, introducing microwaves M from a microwave inlet 105 provided on the side of a cylindrical chamber 109 to generate plasma inside the cylindrical container 103, supplying the plasma to a sample processing chamber 102 connected to the cylindrical container 103, and processing the object to be processed 106 by irradiating the object to be processed 106 held on a holding stand 107 in the sample processing chamber 102 with a gas containing plasma (also called "reactive gas") while exhausting the supplied gas G and the gas containing the processed plasma from a gas exhaust port 108 provided in the sample processing chamber 102.

[0039] Microwave plasma processing involves supplying gas G (e.g., hydrogen gas) from a gas supply port 104 at a flow rate of 0.1 to 10 sccm into a cylindrical container 103 maintained at a pressure of 1 Torr or less, while simultaneously applying an output of 100 to 2000 W (e.g., 2450 MHz and 800 W / cm²) from a microwave inlet 105. 2 A microwave M is introduced, and the microwave, which is in a standing wave state inside the cylindrical container 103, causes a cylindrical reactive gas G inside the cylindrical container 103. A A process is performed on the workpiece 106, which is kept at 0-400°C, while rotating the holding stand 107, until the density reaches 5 × 10 14 pieces / cm 3 Reactive gas G containing the above radicals AThis is done by irradiating for 1 to 20 minutes. As a result, the product of the radical irradiation time and density on the workpiece 106 is 25 × 10 14 Minutes / cm 3 The above can be done. Reactive gas G A The potential difference between the material and the surface of the workpiece 106 is preferably 10 V or less. The reactive gas G after treatment. A The refrigerated and excess gas G is exhausted from the gas exhaust port 108. The radical irradiation density can be determined by known methods (T. Arai el al. (2016) "Selective Heating of Transition Metal Usings Hydrogen Plasma and Its Application to Formation of Nickel Silicide Electrodes for Silicon Ultralarge-Scale Integration Devices" Journal of Materials Science and Chemical Engineering, 2016, 4, 29-33).

[0040] From the perspective of generating hydrogen radicals, hydrogen gas is used as gas G. However, depending on the purpose of the treatment, other gases such as nitrogen, oxygen, carbon dioxide, ammonia, and noble gases (helium, neon, argon, etc.) may be used.

[0041] It is preferable to maintain a pressure of 10 Torr or less inside the cylindrical container 103, or inside the cylindrical container and the cylindrical chamber, more preferably between 1 mTorr and 10 Torr, and most preferably between 10 mTorr and 1 Torr.

[0042] The gas supply rate is preferably 0.01 to 100 sccm, more preferably 0.1 to 10 sccm, and most preferably 0.5 to 5 sccm. If the gas supply rate is less than 0.01 sccm, the reactive gas concentration will not increase sufficiently, and if it is greater than 100 sccm, the exhaust will not keep up, resulting in unstable pressure.

[0043] The gas exhaust velocity is preferably 1 to 10,000 L / min. More preferably 10 to 2,000 L / min, and even more preferably 50 to 1,000 L / min. If the gas exhaust velocity is less than 1 L / min, exhaust takes too long, and if it is greater than 10,000 L / min, the cost becomes too high.

[0044] Microwave output is 10-10000 W / cm². 2 It is preferable to do so at 100-1000 W / cm². 2 It is more preferable to do so at 200-700 W / cm². 2 This is the most preferable. 10 W / cm 2 If the size is smaller, the amount of reactive gas generated will decrease, up to 10,000 W / cm². 2 Making it larger would be too expensive.

[0045] The processing time is preferably 0.001 to 100 minutes, more preferably 0.01 to 50 minutes, and even more preferably 0.05 to 20 minutes. If the processing time is shorter than 0.001 minutes, the effect will be reduced, and if it is longer than 100 minutes, productivity will deteriorate.

[0046] The rotational speed of the holder 107 is preferably 0.1 to 10,000 rpm. More preferably 1 to 1,000 rpm, and even more preferably 10 to 200 rpm. If the rotational speed is slower than 0.1 rpm, unevenness will occur, and if it is faster than 10,000 rpm, the machine's durability will decrease. [Examples]

[0047] The present invention will be described in more detail by the following examples, but the present invention is not limited thereto.

[0048] Comparative Example 1 A model of a microwave plasma generator was fabricated, consisting of a cylindrical container made of quartz (relative permittivity: 3.9) with an inner diameter of 80 mm, an outer diameter of 100 mm, and an axial length of 100 mm, and a cylindrical chamber (made of stainless steel) with an inner diameter of 180 mm, an outer diameter of 200 mm, and an axial length of 100 mm, arranged concentrically, with the top and bottom covered by stainless steel metal plates. In this model, the steady state of electromagnetic waves was calculated using OpenFDTD (manufactured by EEM Co., Ltd.), and the maximum plasma intensity inside the cylindrical container was determined.

[0049] Examples 1-3 As shown in Table 1, models of Examples 1 to 3 were prepared by filling a cylindrical container and a cylindrical chamber with mica (relative permittivity: 6-8), quartz, and polyethylene (relative permittivity: 2.3-2.4) as dielectric materials, respectively, and the maximum plasma intensity inside the cylindrical container was determined in the same manner as in Comparative Example 1.

[0050] Comparative Examples 2 and 3 As shown in Table 1, models of Comparative Examples 2 and 3 were prepared by placing mica and polyethylene, respectively, as dielectric materials on the outer circumference (100-120 mm from the center) of a cylindrical container, and filling the space between these dielectric materials and the cylindrical chamber with air. The maximum plasma intensity inside the cylindrical container was determined in the same manner as in Comparative Example 1.

[0051] Example 4 As shown in Table 1, a model of Example 4 was prepared, in which mica was placed as a dielectric material on the outer circumference of a cylindrical container (in the range of 100 to 120 mm from the center), and quartz was placed as a dielectric material between the mica and the cylindrical chamber. The maximum plasma intensity inside the cylindrical container was determined in the same manner as in Comparative Example 1.

[0052] Example 5 As shown in Table 1, a model of Example 5 was prepared, in which mica was placed as a dielectric material on the outer circumference of a cylindrical container (100-120 mm from the center), quartz was placed as a dielectric material on the outer circumference of the mica (120-140 mm from the center), mica was placed as a dielectric material on the outer circumference of the quartz (140-160 mm from the center), and quartz was placed as a dielectric material on the outer circumference of the quartz (160-180 mm from the center). The maximum plasma intensity inside the cylindrical container was determined in the same manner as in Comparative Example 1.

[0053] Table 1 shows the maximum plasma intensity of each sample as a relative value, with the maximum plasma intensity of Comparative Example 1 set to 1.0. From these results, it can be seen that the microwave plasma generator of the present invention, which is constructed by placing a dielectric material between a cylindrical container and a cylindrical chamber, can obtain a higher plasma intensity than one without a dielectric material.

[0054] [Table 1] Note (1): Relative value with the maximum plasma intensity value of Comparative Example 1 set to 1.0. [Explanation of Symbols]

[0055] 100...Microwave plasma processing equipment 101...Microwave plasma generator 102... Sample Processing Room 103...Cylindrical container C...Central axis 104...Gas supply port 105...Microwave Inlet 106...Item to be processed 107...Holding stand R... Rotation axis 108...Gas exhaust port 109...Cylindrical chamber 110... Dielectric materials 110a, 110b... Dielectric materials 111...Anti-reflection structure G... Gas

Claims

1. A cylindrical container made of a dielectric, A cylindrical chamber is positioned on the outside of the cylindrical container so as to cover the cylindrical container, A gas supply port for supplying gas into the cylindrical container, The cylindrical chamber is provided with a microwave inlet located on its side, A microwave plasma generator for generating plasma along the inner surface of the cylindrical container, A dielectric material other than air is filled between the cylindrical container and the cylindrical chamber. The dielectric material consists of two or more layers of dielectric material arranged to cover the cylindrical container, and the dielectric material closest to the cylindrical container has a dielectric constant higher than that of the cylindrical container. A microwave plasma generator characterized by the following features.

2. In the microwave plasma generator according to claim 1, A microwave plasma generator characterized in that a microwave reflection prevention structure is provided at the microwave inlet.

3. In the microwave plasma generator according to either claim 1 or 2, A microwave plasma generator characterized in that the cylindrical container has an inner diameter of 10 to 300 mm and a thickness of 5 to 100 mm.

4. In the microwave plasma generator according to claim 3, A microwave plasma generator characterized in that the cylindrical container has an inner diameter of 20 to 100 mm and a thickness of 10 to 50 mm.

5. In the microwave plasma generator according to claim 4, A microwave plasma generator characterized in that the cylindrical container has an inner diameter of 30 to 80 mm and a thickness of 15 to 30 mm.

6. A microwave plasma processing apparatus comprising a microwave plasma generator according to any one of claims 1 to 5, and a sample processing chamber connected to the microwave plasma generator and arranged to receive the plasma generated by the microwave plasma generator.

7. In the microwave plasma processing apparatus according to claim 6, The microwave plasma processing apparatus is characterized in that the sample processing chamber comprises a holding stand for holding the object to be processed so that the plasma irradiates the object to be processed, and a gas exhaust port for exhausting the supplied gas and the gas containing the processed plasma.

8. A method for processing the object to be processed using the microwave plasma processing apparatus described in claim 7, Gas is supplied from the gas supply port provided in the cylindrical container of the microwave plasma generator, and microwaves are introduced from the microwave inlet provided on the side of the cylindrical chamber, thereby generating plasma inside the cylindrical container. A microwave plasma processing method characterized by supplying plasma to the sample processing chamber connected to the cylindrical container, and processing the object to be processed by irradiating the object to be processed, which is held on the holding stand in the sample processing chamber, with plasma while exhausting the supplied gas and the processed plasma from the gas exhaust port provided in the sample processing chamber.

9. In the microwave plasma processing method described in claim 8, A microwave plasma treatment method characterized in that the pressure inside the cylindrical container is maintained at 1.3 × 10³ Pa or less.

10. In the microwave plasma processing method described in claim 9, A microwave plasma treatment method characterized in that the inside of the cylindrical container is maintained at a pressure of 1.3 × 10⁻¹ to 1.3 × 10³ Pa.

11. In the microwave plasma processing method according to claim 10, A microwave plasma treatment method characterized in that the inside of the cylindrical container is maintained at a pressure of 1.3 to 1.3 × 10² Pa.

12. In the microwave plasma processing method according to any one of claims 8 to 11, A microwave plasma processing method characterized in that the flow rate of the gas supplied into the cylindrical container is 1.7 × 10⁻⁵ to 1.7 × 10⁻¹ Pa·m³ / s.

13. In the microwave plasma processing method according to claim 12, A microwave plasma processing method characterized in that the flow rate of the gas supplied into the cylindrical container is 1.7 × 10⁻⁴ to 1.7 × 10⁻² Pa·m³ / s.

14. In the microwave plasma processing method described in claim 13, A microwave plasma processing method characterized in that the flow rate of the gas supplied into the cylindrical container is 8.5 × 10⁻⁴ to 8.5 × 10⁻³ Pa·m³ / s.

15. In the microwave plasma processing method according to any one of claims 8 to 14, The output of the microwaves supplied is 10 to 10,000 W / cm². 2 A microwave plasma processing method characterized by the following:

16. In the microwave plasma processing method described in claim 15, The output of the microwaves supplied is 100 to 1000 W / cm². 2 A microwave plasma processing method characterized by the following:

17. In the microwave plasma processing method according to claim 16, The output power of the supplied microwaves is 200-700 W / cm². 2 A microwave plasma processing method characterized by the following:

Images