JP2005268652A - Device and method for plasma treatment - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a plasma treatment device which can be simplified in structure and, in addition, can satisfactorily treat an object to be treated with plasma even when the object is an square substrate or a large-area substrate. <P>SOLUTION: The wall of the vacuum vessel 4 of the plasma treatment device 1 generates the plasma in the vacuum vessel 4 by using an electromagnetic wave radiated into the vessel 4, and performs treatment with the plasma. The vessel is constituted to have at least part of an electromagnetic wave transmission line through which the electromagnetic wave is transmitted. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention includes, for example, a semiconductor element such as a thin film transistor (TFT) or a metal oxide semiconductor element (MOS element), a semiconductor device such as a semiconductor integrated circuit device, or a manufacturing process of a display device such as a liquid crystal display device. The present invention relates to a plasma processing apparatus and a plasma processing method applied to the above.

  Conventionally, in order to perform plasma processing such as film deposition, surface modification, or etching in a manufacturing process of a semiconductor device or a liquid crystal display device, a parallel plate type high-frequency plasma processing device or an electron cyclotron resonance (ECR) plasma is used. A processing device or the like is used.

  However, the parallel plate type plasma processing apparatus has a problem that the plasma density is low and the electron temperature is high. In addition, since the ECR plasma processing apparatus requires a DC magnetic field for plasma excitation, there is a problem that it is difficult to process a large area.

  In recent years, a plasma processing apparatus that can generate a plasma having a high density and a low electron temperature has been proposed to solve such problems.

  As this type of plasma processing apparatus, an apparatus including a circular microwave radiation plate having slots arranged concentrically is known. In this plasma processing apparatus, the microwave introduced from the coaxial tube toward the center of the circular microwave radiation plate is radiated from the slot while propagating in the radial direction of the circular microwave radiation plate. Thereby, since the microwave is introduced into the vacuum container through the electromagnetic wave radiation window, plasma is generated in the vacuum container (see, for example, Patent Document 1).

  The plasma processing apparatus is configured such that microwaves are supplied into the chamber through a dielectric window from two slots forming a waveguide antenna disposed on the H-plane of a rectangular waveguide. Is known. In this plasma processing apparatus, the slot is narrower as it is closer to the reflecting surface. Further, the slot is formed in a stepped shape or a tapered shape so as to become narrower toward the reflection surface of the waveguide (see, for example, Patent Document 2).

Furthermore, as a plasma processing apparatus, a surface wave plasma apparatus in which a plurality of rectangular waveguides are arranged in parallel at equal intervals is known. Each waveguide is provided with a coupling hole having a coupling coefficient sequentially increased toward the tip side. The vacuum vessel is provided with a plurality of dielectric windows divided and formed corresponding to each coupling hole (see, for example, Patent Document 3).
Japanese Patent No. 2722070 Japanese Patent No. 2857090 JP 2002-280196 A

  However, when a microwave is propagated in a conductor such as a coaxial tube or a circular microwave radiation plate as in the plasma processing apparatus described in Patent Document 1, a propagation loss such as a copper loss occurs in the conductor. This propagation loss increases as the frequency increases and as the coaxial transmission distance and radiation plate area increase. Therefore, even if a plasma processing apparatus corresponding to a relatively large substrate such as a liquid crystal display device is designed using the technique described in Patent Document 1, the microwave attenuation is large and it is difficult to efficiently generate plasma. It is. In addition, since the plasma processing apparatus described in Patent Document 1 is configured to emit microwaves from a circular microwave radiation plate, when applied to a square substrate such as a liquid crystal display device, the corner of the substrate is used. There is also a problem that the plasma becomes non-uniform in the area.

  In addition, as in the case of the plasma processing apparatus described in Patent Document 2, when a microwave propagated in a rectangular waveguide is radiated from two slots, if there are many negative ions in the generated plasma, There is a problem that the ambipolar diffusion coefficient becomes small. Therefore, in the technique described in Patent Document 2, plasma generation is biased to the vicinity of the slot where the microwave is radiated. Further, this plasma bias becomes more prominent when the plasma pressure is high. Therefore, in the plasma processing apparatus described in Patent Document 2, it is difficult to perform plasma processing on a large substrate using a gas containing oxygen, hydrogen, chlorine, or the like that easily generates negative ions as a raw material. If it is high, it becomes even more difficult. Furthermore, since the distribution of the slots constituting the waveguide antenna is localized (not uniform) on the processing surface of the substrate subjected to plasma processing, the plasma density tends to be non-uniform.

Moreover, in the technique described in Patent Document 1 or 2, the electromagnetic wave emission window (dielectric window) has a thickness that can withstand a gas pressure difference between substantially atmospheric pressure and a pressure close to a vacuum, that is, a force of about 1 kg / cm ^2. It is necessary to design for (strength). This is because, in the case of performing plasma processing, generally, after the vacuum vessel (chamber) is once evacuated, process gas or the like is introduced into the vacuum vessel. Therefore, when designing a plasma processing apparatus that performs plasma processing on a large substrate of 1 m square using the technique described in Patent Document 1 or 2, the thickness of the electromagnetic wave transmission window made of synthetic quartz or the like is very large. It is not practical because it becomes thicker.

  Furthermore, in the technique described in Patent Document 3, since the waveguides are spaced apart from each other, it is difficult to uniformly distribute the coupling holes so as to correspond to the entire surface of the substrate to be processed. . Further, since it is necessary to provide a seal for sealing the vacuum as many as the number of coupling holes, the structure of the vacuum vessel is likely to be complicated. In addition, since the processing cost of the top plate of the vacuum vessel increases, there is a problem that the apparatus price increases.

  The present invention has been made based on such circumstances, and can simplify the structure and generate a uniform plasma with a large area, such as a square substrate or a large area substrate. It is an object of the present invention to provide a plasma processing apparatus and a plasma processing method that can satisfactorily perform plasma processing even on a to-be-treated object.

  The plasma processing apparatus according to claim 1 of the present invention is a plasma processing apparatus for generating plasma in the processing container by the electromagnetic wave radiated from the electromagnetic wave radiating portion in the processing container, and performing plasma processing by the plasma. The wall of the processing container has at least a part of an electromagnetic wave transmission path for transmitting electromagnetic waves.

  In the present invention and the following invention, the “electromagnetic wave transmission path” refers to a line for transmitting electromagnetic waves with high efficiency. Examples of the electromagnetic wave transmission path include a coaxial tube, a waveguide, and a cavity resonator.

  The coaxial tube has a larger loss (propagation loss) than the waveguide, but does not have a cut-off frequency. Therefore, the transmission frequency range is wide and the transmission path can be downsized even when the wavelength is large.

  Since the waveguide does not have a central conductor that causes a loss in the coaxial tube, the loss is small and it is suitable for transmission of high power. However, there is a cut-off frequency and the transmittable frequency range is narrow. Further, the shape is substantially defined by the frequency of the electromagnetic wave to be transmitted.

  The cavity resonator is designed so that a standing wave stands for a specific frequency, and has an effect of strengthening an electromagnetic wave having that wavelength.

  The “electromagnetic radiation portion” refers to a portion that emits an electromagnetic wave transmitted through the electromagnetic wave transmission path to the outside of the electromagnetic wave transmission path. Examples of the electromagnetic wave radiation portion include a slot, a conductor rod, and an electromagnetic horn.

  According to the plasma processing apparatus of the first aspect of the present invention, since the wall of the processing container has at least a part of the electromagnetic wave transmission path, the configuration of the processing container and the plasma apparatus itself can be simplified. . In addition, by adjusting the shape and arrangement of the electromagnetic wave transmission path, stable and uniform plasma can be generated in the processing container regardless of the size and shape of the processing container. Therefore, even a target object such as a square substrate or a large-area substrate can be plasma-processed satisfactorily. Moreover, according to the plasma processing apparatus of Claim 1 of this invention, it is possible to produce | generate uniform plasma with a large area.

The plasma processing apparatus according to claim 2 of the present invention includes an electromagnetic wave transmission path for transmitting electromagnetic waves,
An electromagnetic wave radiation part for electromagnetic wave radiation coupled to the electromagnetic wave transmission path, and a treatment container, and plasma is generated in the treatment container by electromagnetic waves radiated from the electromagnetic wave radiation part into the treatment container, In the plasma processing apparatus for performing plasma processing using plasma, at least a part of the electromagnetic wave transmission path and a wall constituting the processing container are integrated.

  According to the plasma processing apparatus of the second aspect of the present invention, the electromagnetic wave transmission path and the wall constituting the processing container are integrated. That is, since the electromagnetic wave transmission path for introducing electromagnetic waves can be a part of the processing container, the configuration of the processing container and the plasma apparatus itself can be simplified. In addition, by adjusting the shape and arrangement of the electromagnetic wave transmission path, stable and uniform plasma can be generated in the processing container regardless of the size and shape of the processing container. Therefore, even a target object such as a square substrate or a large-area substrate can be plasma-processed satisfactorily. This also facilitates device design taking into account the flow of process gas and the like, and facilitates degassing, cleaning, and the like in the processing container. For this reason, a to-be-processed object can be plasma-processed by stable and uniform plasma. Furthermore, according to the plasma processing apparatus of the second aspect of the present invention, it is possible to generate a uniform plasma with a large area.

  According to a third aspect of the present invention, there is provided a plasma processing apparatus comprising: an electromagnetic wave transmission path for transmitting an electromagnetic wave; an electromagnetic wave radiation portion for electromagnetic wave radiation coupled to the electromagnetic wave transmission path; and a processing container. A plasma processing apparatus for generating plasma in the processing container by electromagnetic waves radiated from the section into the processing container and performing plasma processing with the plasma, and at least a part of a tube wall conductor forming the electromagnetic wave transmission path Serves also as a wall constituting the processing container.

  According to the plasma processing apparatus of the third aspect of the present invention, since at least a part of the tube wall conductor forming the electromagnetic wave transmission path also serves as a wall constituting the processing container, the processing container and the plasma apparatus itself The configuration can be simplified. In addition, by adjusting the shape and arrangement of the electromagnetic wave transmission path, stable and uniform plasma can be generated in the processing container regardless of the size and shape of the processing container. Therefore, even a target object such as a square substrate or a large-area substrate can be plasma-processed satisfactorily. This also facilitates device design taking into account the flow of process gas and the like, and facilitates degassing, cleaning, and the like in the processing container. For this reason, a to-be-processed object can be plasma-processed by stable and uniform plasma. Furthermore, according to the plasma processing apparatus of claim 3 of the present invention, it is possible to generate a uniform plasma with a large area.

  When the plasma processing apparatus according to the first to third aspects of the present invention is implemented, at least a part of the electromagnetic wave transmission path can be provided, for example, in the wall of the processing container. In other words, in the plasma processing apparatus according to the first to third aspects of the present invention, for example, a tunnel-like space that penetrates the wall is provided along the wall, so that the electromagnetic wave transmission path is formed in the wall of the processing container. At least a portion can be provided.

  However, considering the ease of processing the wall, etc., a processing container having a processing chamber in which the object to be processed is plasma-treated is adopted, and at least a part of the electromagnetic wave transmission path is connected to the processing chamber of the processing container wall. Is preferably provided on the inner surface of the wall. In this case, since at least a part of the electromagnetic wave transmission path can be defined by the inner surface of the wall of the processing container, it is easier than providing a part of the electromagnetic wave transmission path to penetrate the wall of the processing container. A part of the electromagnetic wave transmission path can be provided on the wall.

  Further, when providing at least a part of the electromagnetic wave transmission path on the inner surface of the wall that defines the processing chamber of the wall of the processing vessel, the inner surface of the wall is provided with a recess that defines at least a part of the electromagnetic wave transmission path, A slot plate having a plurality of slots may be employed as the electromagnetic wave radiation portion, and the recess may be covered from the processing chamber side by this slot plate. At this time, the plurality of slots are made to correspond to the recesses, respectively. By doing in this way, an electromagnetic wave transmission path can be provided in the space surrounded by the wall surface defining the recess and the slot plate. Moreover, the electromagnetic wave transmitted through the electromagnetic wave transmission path can be radiated into the processing chamber through the slot.

  In addition, when the concave portion for defining at least a part of the electromagnetic wave transmission path is provided on the inner surface of the wall and the concave portion is covered from the processing chamber side by the slot plate, the electromagnetic wave transmission path is provided in the same closed space as the processing chamber. It will be. Therefore, electromagnetic waves can be made incident in the processing chamber without providing an electromagnetic wave transmission window made of synthetic quartz or the like in the processing container.

  In other words, the configuration as described above eliminates the need to provide an electromagnetic wave transmission window made of synthetic quartz or the like in the processing container, so that all the sealing mechanisms between the electromagnetic wave transmission window and the electromagnetic wave transmission window and the wall of the processing container are provided. Can be omitted. Therefore, the configuration of the processing vessel and the plasma apparatus itself can be further simplified.

  Moreover, since the electromagnetic wave transmission window itself can be omitted, it is of course unnecessary to consider the strength of the electromagnetic wave transmission window (the thickness of the synthetic quartz window). Therefore, it is possible to easily design a plasma processing apparatus including a large processing container corresponding to a large-scale object to be processed. Moreover, there is no cost increase associated with the increase in size of the electromagnetic wave transmission window. Further, since the influence of the electromagnetic wave transmission window on the propagation of the electromagnetic wave can be eliminated, it is easy to design an apparatus that can uniformly radiate the electromagnetic wave into the processing container. Therefore, it is possible to obtain a plasma processing apparatus capable of performing plasma processing with stable and uniform plasma even for a target object such as a large-area substrate.

  In the case where a recess defining at least a part of the electromagnetic wave transmission path is provided on the inner surface of the wall and the recess is covered from the processing chamber side by the slot plate, a dielectric member for covering so as to cover the slot plate in the processing chamber It is good to provide. By doing so, plasma can be generated satisfactorily in the processing chamber by the electromagnetic wave radiated from the electromagnetic wave radiation part.

  By the way, when a covering dielectric member is provided in the processing chamber so as to cover the slot plate, surface wave plasma can be generated in the processing chamber. That is, when a predetermined process gas is introduced into the processing container (inside the processing chamber) and electromagnetic waves are incident on the processing container, the process gas is excited to generate plasma, and the vicinity of the area surface where the electromagnetic waves are incident The electron density in the plasma (near the slot in the processing chamber) increases. As the electron density in the plasma near the region where the electromagnetic wave is incident increases, it becomes difficult for the electromagnetic wave to propagate through the plasma and attenuates within the plasma. Therefore, since the electromagnetic wave does not reach the region away from the vicinity of the region where the electromagnetic wave is incident, the region where the process gas is excited by the electromagnetic wave is limited to the vicinity of the region where the electromagnetic wave is incident. Thereby, surface wave plasma is generated.

  In plasma treatment using surface wave plasma, damage to the object to be processed due to ions can be suppressed. That is, in a state where surface wave plasma is generated, a region where the energy of the electromagnetic wave is applied and the compound is ionized is localized in the vicinity of the region where the electromagnetic wave is incident. Therefore, the electron temperature in the vicinity of the surface to be processed of the object to be processed can be kept low by providing the object to be processed at a predetermined distance from the region where the electromagnetic wave is incident. That is, since an increase in the electric field of the sheath generated in the vicinity of the surface to be processed of the object to be processed can be suppressed, the incident energy of ions to the object to be processed is reduced, and damage to the object to be processed by ions is suppressed.

  Therefore, by providing a covering dielectric member in the processing chamber so as to cover the slot plate, a plasma processing apparatus capable of suppressing ion damage to the object to be processed can be obtained.

  Some processing containers have a lid that can be removed from the container body for cleaning and maintenance of the processing chamber. Thus, in the processing container in which the container main body and the lid are separate, it is preferable to provide the electromagnetic wave transmission path on the lid rather than providing the electromagnetic wave transmission path on the container main body. It is possible to easily design the apparatus.

  Therefore, when implementing the plasma processing apparatus according to the first to third aspects of the present invention, as a processing container having a processing chamber, a container body having a bottom wall and a peripheral wall and opening at least in one side, and an opening of the container body A wall that defines the processing chamber of the walls of the processing container, and has a bottom wall and a peripheral wall of the container main body and a cover, and at least a part of the electromagnetic wave transmission path Is preferably provided on the lid of the processing vessel.

  A plasma processing apparatus according to a fourth aspect of the present invention is the plasma processing apparatus according to any one of the first to third aspects, wherein a dielectric member is provided in the electromagnetic wave transmission line, Airtightness of the processing container is maintained by the dielectric member, and electromagnetic waves are introduced into the processing container from the outside of the processing container through the dielectric member.

  For example, an electromagnetic wave emission waveguide as a part of the electromagnetic wave transmission path provided on the wall of the processing container, and the electromagnetic wave transmission path provided outside the processing container and transmitting the electromagnetic wave to the electromagnetic wave emission waveguide In the case of connecting an electromagnetic wave distribution waveguide as a part of the container, a seal is placed between the processing container and a member such as an electromagnetic wave distribution waveguide in order to keep the processing container airtight. It is necessary to provide a stopping mechanism. The plasma processing apparatus according to claim 4 of the present invention is the above-described case, that is, the electromagnetic wave radiation waveguide provided on the wall of the processing container, and the electromagnetic wave distribution waveguide provided outside the processing container. By connecting the waveguide, it is preferable when the processing container and the electromagnetic wave distribution waveguide are integrated.

  By doing so, one of the electromagnetic wave transmission paths provided on the wall of the processing container from the outside of the processing container is maintained without complicating the configuration of the processing container and the plasma processing apparatus itself and maintaining the airtightness of the processing container. Electromagnetic waves can be introduced into the part. In general, the dielectric member is easily damaged and is expensive. On the other hand, by setting it as the above structures, the area | region where atmospheric pressure is applied to the dielectric material member which maintains the airtightness of a process container can be made into the cross-sectional area of a waveguide. In other words, with this configuration, the load applied to the dielectric member that maintains the hermeticity of the processing container can be made relatively small, so that damage to the dielectric member can be suppressed. In addition, since the dielectric member that keeps the airtightness of the processing container is provided in the electromagnetic wave transmission path, it is possible to suppress the plasma generated in the processing container from entering the electromagnetic wave transmission path. Furthermore, it is easy to design the apparatus in consideration of the flow of the process gas and the like, and it is easy to degas and clean the processing container.

  A plasma processing apparatus according to a fifth aspect of the present invention is the plasma processing apparatus according to any one of the first to fourth aspects, wherein the region is located in the processing container in the electromagnetic wave transmission path. A dielectric member is provided on at least a part of each. In other words, the electromagnetic wave transmission line has a dielectric member in the electromagnetic wave transmission line, and electromagnetic waves are transmitted through the dielectric member in the electromagnetic wave transmission line. In other words, the dielectric member itself in the electromagnetic wave transmission path becomes a part of the electromagnetic wave transmission path.

  By doing in this way, it can suppress that the plasma produced | generated in the processing container penetrate | invades in the electromagnetic wave transmission path.

  The plasma processing apparatus according to claim 6 of the present invention is the plasma processing apparatus according to any one of claims 1 to 5, wherein the electromagnetic wave radiation portion is a slot plate having a plurality of slots. The slot plate is provided in the processing container, and a dielectric member for coating is provided so as to cover the slot plate.

  Thus, by providing the covering dielectric member in the processing chamber so as to cover the slot plate, the surface wave can be propagated. Therefore, it is possible to perform plasma processing with surface wave plasma that has high density using surface waves and little ion damage to the object to be processed. Furthermore, a target object such as a large-area substrate can be subjected to plasma processing using surface wave plasma that is stable and uniform and causes little damage to the target object. Further, since the slot is closed by the covering dielectric member, the generated plasma does not enter the electromagnetic wave transmission path through the slot and the wall surface defining the electromagnetic wave transmission path is not damaged. In addition, the input electromagnetic wave power can be supplied into the processing container with high efficiency.

  In addition, when a part of the electromagnetic wave transmission path provided on the wall of the processing container is provided in the same closed space as the inside of the processing container (the processing chamber of the processing container), the covering dielectric member is also typically used. It is provided in the same closed space as in the processing container. In such a case, the coating dielectric member is not subjected to such a large force as the gas pressure difference between the substantially atmospheric pressure and the pressure close to the vacuum. Therefore, even if the plasma processing apparatus is enlarged, it is not necessary to give strength to the covering dielectric. Therefore, there is no cost increase associated with increasing the strength of the covering dielectric member (thickening the thickness). Further, since the covering dielectric member can be designed to be relatively thin, the influence of the covering dielectric member on the propagation of electromagnetic waves can be reduced. Therefore, it is easy to design an apparatus for uniformly radiating electromagnetic waves into the processing container.

  In addition, as the dielectric member for covering, a member formed so that the inner surface of the processing container is a flat surface can be used. In this case, when the surface wave plasma is generated, it is possible to prevent the exposed surface of the covering dielectric member from blocking the propagation of the surface wave, so that the plasma spreads not only around the slot where the electromagnetic wave is emitted but also on the entire surface. It becomes easy. Therefore, it is possible to easily design a large plasma processing apparatus capable of performing plasma processing on an object to be processed such as a large area substrate. In addition, a plasma processing apparatus with a small footprint and a uniform plasma density can be provided.

  On the other hand, as the dielectric member for covering, a member having an uneven surface on the inside of the processing container may be used. In this case, it can suppress that only the specific mode of a surface wave propagates. Therefore, the in-plane distribution of plasma due to the mode can be improved. Also in this case, it is possible to easily design a large plasma processing apparatus capable of performing plasma processing on an object to be processed such as a large area substrate. In addition, a plasma processing apparatus with a small footprint and a uniform plasma density can be provided.

  In addition, a cooling pipe as a cooling mechanism may be provided in a region corresponding to between adjacent slots in the wall of the processing container, and a refrigerant (fluid) may be circulated in the cooling pipe. By doing so, the electromagnetic wave transmission path can be efficiently cooled by the refrigerant without hindering the generation of plasma.

  A plasma processing apparatus according to a seventh aspect of the present invention is the plasma processing apparatus according to the sixth aspect, wherein a dielectric member is provided in the slot.

  When a dielectric member is provided in the electromagnetic wave transmission path of the processing container wall (in the case of the electromagnetic wave transmission path having a waveguide for electromagnetic wave emission), in the electromagnetic wave transmission path Is filled with a dielectric member, and the inside of the slot is filled with air, for example. That is, since the dielectric constant in the electromagnetic wave transmission path is different from the dielectric constant in the slot, part of the electromagnetic wave transmitted through the electromagnetic wave transmission path is reflected at the interface with the slot. In addition, a part of the electromagnetic wave is also reflected at the interface between the slot and the covering dielectric member.

  On the other hand, if a dielectric member is provided in the slot, the difference between the dielectric constant in the electromagnetic wave transmission path and the dielectric constant in the slot can be reduced, so that the electromagnetic wave reflection at the interface between the electromagnetic wave transmission path and the slot can be reduced. Can be suppressed. In addition, since the difference between the dielectric constant in the slot and the dielectric member for coating can be reduced, reflection of electromagnetic waves at the interface between the slot and the dielectric member for coating can be suppressed. it can.

  The plasma processing apparatus according to claim 8 of the present invention is the plasma processing apparatus according to claim 6 or 7, wherein the electromagnetic wave transmission line has a plurality of rectangular waveguides for electromagnetic wave radiation. The plurality of slots are provided so as to correspond to the E plane (electric field plane) or H plane (magnetic field plane) of the electromagnetic wave radiation rectangular waveguide, respectively.

  By doing so, it is possible to simplify the structure and realize a plasma processing apparatus that can satisfactorily perform plasma processing even on a target object such as a rectangular substrate or a large-area substrate. .

  When the plurality of slots are provided on the H plane, the slots are provided on the plane having the long side of the rectangular waveguide cross section as one side, so that the slot processing and the slot position adjustment are facilitated. In addition, since the slot width can be increased, more electromagnetic waves can be radiated.

  When the plurality of slots are provided on the E surface, the slots are provided on the surface having the short side of the rectangular waveguide cross section as one side, so that the rectangular waveguides are arranged in parallel with each other at regular intervals in a certain area. When arranged, a larger number of rectangular waveguides can be arranged as compared with the case where a plurality of slots are provided on the H plane. Thereby, the uniformity of electromagnetic waves can be increased.

  A plasma processing apparatus according to a ninth aspect of the present invention is the plasma processing apparatus according to the eighth aspect, wherein the plurality of rectangular waveguides for radiating electromagnetic waves each have an electromagnetic wave frequency. The rectangular waveguides are set to sizes that can be transmitted in the fundamental mode. These rectangular waveguides for electromagnetic wave radiation are arranged in parallel to each other, and the interval is set to 50 cm or less.

When enabling the frequency of electromagnetic waves to be transmitted in the fundamental mode in a rectangular waveguide, for example, the dielectric constant of the rectangular waveguide for electromagnetic wave radiation is ε, and the major axis of the inner cross-sectional dimension of the rectangular waveguide for electromagnetic wave radiation Where a is the wavelength λ of the electromagnetic wave,
(Λ / ε ^0.5 ) <2a (1)
This can be realized by designing so as to satisfy the above condition.

  The interval (pitch) d between the rectangular waveguides for electromagnetic wave radiation is preferably set in consideration of the degree of plasma diffusion. FIG. 11 shows the relationship between the distance from the particle generation point and the particle density. As shown in FIG. 11, it can be seen that the lower the pressure of the process gas, the more the particles diffuse.

  When the pressure of the process gas is 0.1 Pa or less, since the plasma is easily diffused, the interval d between the rectangular waveguides for electromagnetic wave emission may exceed 50 cm. However, in the plasma processing apparatus, the pressure of the process gas is generally about 1 Pa or more. When the pressure of the process gas is 1 Pa or more, the inventors of the present application set the upper limit to 50 cm and the interval between the rectangular waveguides for electromagnetic wave radiation so as to correspond to the assumed pressure of the process gas. It has been found that if d is set, it is easy to generate a uniform plasma even under conditions where the plasma is difficult to diffuse.

  As described above, by allowing the electromagnetic wave frequency to be transmitted in the fundamental mode in the rectangular waveguide, the amount of propagation loss of the electromagnetic wave for generating plasma in the rectangular waveguide for electromagnetic wave emission is reduced. Can do. Moreover, by setting the interval d between the rectangular waveguides for electromagnetic wave radiation to 50 cm or less, the plasma can be satisfactorily obtained even under conditions in which the plasma is difficult to diffuse, for example, when the pressure of the process gas in the processing container is high. It can be diffused uniformly.

A plasma processing apparatus according to a tenth aspect of the present invention is the plasma processing apparatus according to the ninth aspect, wherein the dielectric constant of the rectangular waveguide for electromagnetic wave emission is ε, and The major axis of the inner cross-sectional dimension of the rectangular waveguide is a with respect to the wavelength λ of the electromagnetic wave.
(Λ / ε ^0.5 ) <2a (1)
The angular frequency of the electromagnetic wave is ω, the dielectric constant of the dielectric member for coating is ε _d , the speed of light is c, the charge amount of electrons is e, the dielectric constant of vacuum is ε ₀ , and the electron density is n _e, when the electron mass and the m _e, these plasma angular frequency omega _P
ω _P = (e ² × n _e / (ε ₀ × m _e )) ^0.5 (2)
Wave number k defined by
k = ω / c ((ε _d (ω _p ² −ω ² )) / (ω _p ² − (1 + ε _d ) ω ² )) ^0.5 (3)
Is the internal dimension L in the direction orthogonal to the rectangular waveguide for electromagnetic wave radiation of the processing container,
k = mπ / L (m is an integer of 1 ≦ m ≦ 2L / (λ / ε ^0.5 )) (4)
The rectangular waveguide for electromagnetic wave radiation is
λ _swp = π / k (5)
_Are arranged at positions where the wavelength of the standing wave is guided by λ _swp and the amplitude of the standing wave is substantially maximized.

FIG. 12 schematically shows a standing wave of m = 1 in the processing container, and FIG. 13 schematically shows a standing wave of m = 2 L / (λ / ε ^0.5 ) in the processing container. Is shown. As can be seen from FIGS. 12 and 13, the wavelength λ _{swp of the} standing wave is _obtained by _setting the range of m in the equation (4) to an integer of 1 ≦ m ≦ 2L / (λ / ε ^0.5 ). be able to.

In this way, by _arranging the rectangular wave guides for electromagnetic wave radiation near the position where the standing wave has the maximum wavelength λ _swp interval and the wavelength of the standing wave of the low order of the surface wave, the efficiency is improved. The surface wave can be well supplied with electromagnetic energy.

  In addition, the distance between the inner surfaces of adjacent rectangular waveguides for electromagnetic wave radiation is set between the inner surfaces of one rectangular waveguide for electromagnetic wave radiation so that the electromagnetic waves are uniformly radiated into the processing container through the slots. You may set so that it may become smaller than a width | variety. By doing so, it is possible to easily design a large plasma processing apparatus for performing plasma processing on an object to be processed such as a large-area substrate. In addition, a plasma processing apparatus with a small footprint and a uniform plasma density can be provided.

  A plasma processing apparatus according to an eleventh aspect of the present invention is the plasma processing apparatus according to the sixth aspect, wherein at least a part of a region located in the processing container in the electromagnetic wave transmission path is a dielectric. A dielectric member is provided in the slot, and the dielectric member in the electromagnetic wave transmission path and the dielectric member in the slot have a substantially constant dielectric constant in the frequency band of the electromagnetic wave. Are the same.

  As described above, by providing the dielectric member in the slot, it is possible to reduce the dielectric constant difference between the electromagnetic wave transmission path having the dielectric member in the electromagnetic wave transmission path and the slot. Therefore, the electromagnetic wave propagating through the electromagnetic wave transmission path having the dielectric member in the electromagnetic wave transmission path can be suppressed from being reflected at the interface with the slot, and therefore, the electromagnetic wave can be efficiently radiated into the processing container. Can do.

  In addition, the dielectric member in the electromagnetic wave transmission line and the dielectric member in the slot have substantially the same dielectric constant in the frequency band of the electromagnetic wave, thereby reflecting the electromagnetic wave at the interface between the electromagnetic wave transmission line and the slot. Can be substantially eliminated. Thereby, electromagnetic waves can be supplied into the processing container more efficiently.

  A plasma processing apparatus according to claim 12 of the present invention is the plasma processing apparatus according to claim 6, wherein the dielectric member for the electromagnetic wave transmission path is at least one of quartz, alumina, and fluororesin. It consists of one.

  By doing in this way, the loss of electromagnetic waves due to dielectric loss can be suppressed. In addition, by using a fluororesin as a dielectric member in the electromagnetic wave transmission path, the weight of the waveguide is reduced compared to the case of using an inorganic dielectric member such as quartz while suppressing loss of electromagnetic waves due to dielectric loss. Can be reduced. Moreover, damage due to impact or the like can be made less likely to occur than when an inorganic dielectric member such as quartz is used.

  The plasma processing apparatus according to claim 13 of the present invention is the plasma processing apparatus according to claim 8, further comprising an electromagnetic wave source, and the electromagnetic wave transmission path generated by the electromagnetic wave source. An electromagnetic wave distributing waveguide for distributing the electromagnetic wave to the plurality of electromagnetic wave radiation rectangular waveguides, and a dielectric member is provided in the electromagnetic wave transmission path; The member maintains the hermeticity of the processing container, and electromagnetic waves are introduced into the processing container from the outside of the processing container through the dielectric member.

  By doing so, electromagnetic waves can be introduced from the outside of the processing container into the processing container without complicating the configuration of the processing container and the plasma processing apparatus itself and while maintaining the airtightness of the processing container. In general, the dielectric member is easily damaged and is expensive. However, by adopting the above-described configuration, a region in which atmospheric pressure is applied to the dielectric member that holds the processing container in an airtight manner is used for the electromagnetic wave emission. The cross-sectional area of the waveguide may be approximately the same. In addition, since the dielectric member for holding the processing container in an airtight manner is provided in the electromagnetic wave transmission path, it is possible to suppress the plasma generated in the processing container from entering the electromagnetic wave transmission path. Furthermore, it is easy to design the apparatus in consideration of the flow of the process gas and the like, and it is easy to degas and clean the processing container.

  Further, when the electromagnetic wave is distributed from one electromagnetic wave distribution waveguide to a plurality of electromagnetic wave emission waveguides, the sealing portion for keeping the processing vessel airtight is provided for electromagnetic wave distribution. It can be one place about the cross-sectional area of the waveguide. With such a configuration, the configuration of the plasma processing apparatus can be simplified. Even in such a case, the process container can be kept airtight by the dielectric member that keeps the process container airtight.

  Note that “the plurality of rectangular waveguides for electromagnetic wave radiation and the walls constituting the processing container are integral” means that the plurality of rectangular waveguides for electromagnetic wave radiation and the walls constituting the processing container are integrated. It includes not only those integrally formed but also those in which an electromagnetic wave radiation waveguide is connected to a wall constituting the processing vessel to form an integral structure. In addition, the dielectric member that holds the processing container in an airtight manner may be an integrally molded product with the dielectric member in the electromagnetic wave transmission path. That is, a part of the dielectric member in the electromagnetic wave transmission path may also serve as a dielectric member that holds the processing container in an airtight manner.

  A plasma processing apparatus according to a fourteenth aspect of the present invention is the plasma processing apparatus according to the thirteenth aspect, wherein the plurality of rectangular waveguides for electromagnetic wave radiation are E of the waveguides for electromagnetic wave distribution. It is provided so as to branch from the surface or the H surface.

  A plasma processing apparatus according to a fifteenth aspect of the present invention is the plasma processing apparatus according to the thirteenth aspect, wherein the waveguide for electromagnetic wave distribution is bent at a right angle so that the propagation direction of the electromagnetic wave changes by 90 °. In addition, an electromagnetic wave whose propagation direction is changed by 90 ° is distributed to the plurality of rectangular waveguides for electromagnetic wave radiation.

  By doing so, it is possible to easily design a large plasma processing apparatus capable of performing plasma processing on an object to be processed such as a large-area substrate. In addition, a plasma processing apparatus with a small footprint and a uniform plasma density can be provided.

  A plasma processing apparatus according to a sixteenth aspect of the present invention is the plasma processing apparatus according to the fourteenth aspect, wherein the plurality of rectangular waveguides for electromagnetic wave radiation are E of the waveguide for electromagnetic wave distribution. The plurality of rectangular waveguides for electromagnetic wave radiation and the waveguides for electromagnetic wave distribution are arranged on substantially the same plane.

  Since the plurality of rectangular waveguides and the waveguide for electromagnetic wave distribution are arranged on substantially the same plane, the cross-sectional area of the sealing portion for increasing the size of the plasma processing apparatus or keeping the processing vessel airtight. It is possible to easily design a large-sized plasma processing apparatus capable of performing plasma processing on an object to be processed such as a large area substrate. In addition, a plasma processing apparatus with a small footprint and a uniform plasma density can be provided.

  In the plasma processing apparatus according to claim 17 of the present invention, a dielectric member for an electromagnetic wave transmission path is provided in at least a part of a region located in the processing container in the electromagnetic wave transmission path, A dielectric member is provided in the slot, and the dielectric member in the electromagnetic wave transmission path, the dielectric member in the slot, and the dielectric member for covering are assembled together. .

  In this way, when the dielectric member in the slot is damaged or the dielectric member in the slot needs to be replaced due to redesign of the slot, etc., the dielectric member in the slot is replaced. Can be easily performed. Therefore, a plasma processing apparatus that can be easily maintained can be provided.

  The plasma processing apparatus according to claim 18 of the present invention is the plasma processing apparatus according to claim 6, wherein the covering dielectric member is fixed by a fixture made of a dielectric material.

  By doing in this way, the disturbance of the electromagnetic wave in the location which fixes the dielectric material for a coating | cover can be suppressed. Therefore, it is possible to easily design a large plasma processing apparatus capable of performing plasma processing on an object to be processed such as a large area substrate. In addition, a plasma processing apparatus with a small footprint and a uniform plasma density can be provided.

  The plasma processing apparatus according to claim 19 of the present invention is the plasma processing apparatus according to claim 6, wherein the covering dielectric member is formed in a plate shape covering the slot plate, The thickness is set smaller than ¼ of the wavelength of the electromagnetic wave in the covering dielectric member.

  By doing in this way, it can suppress that electromagnetic waves propagate in the thickness direction of the dielectric material for coating. That is, only the surface wave can be selectively propagated in the covering dielectric member. Therefore, it is possible to easily design a large plasma processing apparatus capable of performing plasma processing on an object to be processed such as a large area substrate. In addition, a plasma processing apparatus with a small footprint and a uniform plasma density can be provided.

  A plasma processing apparatus according to a twentieth aspect of the present invention is the plasma processing apparatus according to the fourth or fifth aspect, wherein the electromagnetic wave transmission path and the dielectric member for holding the processing container in an airtight manner or the The interval with the dielectric member in the electromagnetic wave transmission path is set to 1 mm or less.

  Since the electromagnetic wave transmission path is generally formed of a conductive material, if the distance between the dielectric member for holding the processing vessel airtight or the dielectric member in the electromagnetic wave transmission path exceeds 1 mm, the electromagnetic wave An abnormal discharge may occur between the inner surface of the transmission path and the dielectric member for holding the processing container in an airtight manner or the dielectric member in the electromagnetic wave transmission path.

  Therefore, the distance between the electromagnetic wave transmission path and the dielectric member for holding the processing container in an airtight manner or the dielectric member in the electromagnetic wave transmission path is preferably set to 1 mm or less. Abnormal discharge generated in the gap between the transmission line and the dielectric member for holding the processing vessel in an airtight manner or the dielectric member in the electromagnetic wave transmission line can be suppressed. Therefore, stable plasma can be generated in the processing container.

  A plasma processing apparatus according to a twenty-first aspect of the present invention is the plasma processing apparatus according to any one of the first to fourth aspects, wherein the electromagnetic wave supplies an electromagnetic wave having a frequency of 10 MHz to 25 GHz to the electromagnetic wave transmission line. A source is further provided.

  The electromagnetic wave source may be at least one or more, but by using a plurality of electromagnetic wave sources, a desired output can be obtained without increasing the maximum output of each electromagnetic wave source. However, when using a plurality of electromagnetic wave sources, if the adjacent electromagnetic wave sources have the same frequency, interference between the generated plasmas is likely to occur. Therefore, when a plurality of electromagnetic wave sources are used, it is preferable that the adjacent electromagnetic wave sources have different frequencies.

  As an electromagnetic wave source, electromagnetic waves having frequencies of 13.56 MHz, 27.12 MHz, 40.68 MHz, 915 MHz, 2.45 GHz, 5.8 GHz, and 24.125 GHz, which are industrial frequency bands (ISM frequency band), are supplied. A thing can be used suitably. By doing so, the influence on the communication frequency band can be reduced, so that leakage electromagnetic waves can be easily shielded.

  A plasma processing apparatus according to a twenty-second aspect of the present invention is the plasma processing apparatus according to the twenty-first aspect, wherein the electromagnetic wave source supplies an electromagnetic wave having a frequency of 2.45 GHz ± 50 MHz to the electromagnetic wave transmission line. It is.

  The frequency of the microwave source is currently 2.45 GHz. Therefore, such electromagnetic wave sources are inexpensive and abundant in variety. In addition, by setting the frequency range to 2.45 GHz ± 50 MHz, an industrial frequency band is obtained, the influence on the communication frequency band can be reduced, and the leakage electromagnetic wave of the apparatus can be easily shielded. By doing so, microwaves can be supplied as electromagnetic waves into the processing container.

  A plasma processing apparatus according to a twenty-third aspect of the present invention is the plasma processing apparatus according to any one of the first to twenty-first aspects, wherein plasma oxidation, plasma film formation, or plasma etching is performed using surface wave plasma. Under the conditions.

  According to the plasma processing apparatus of the twenty-third aspect, the object to be processed can be subjected to oxidation treatment, film formation, or etching while suppressing ion damage to the object to be processed.

  The plasma processing apparatus according to any one of claims 1 to 23, wherein an object to be processed is disposed inside a processing container, and plasma is generated inside the processing container, whereby the object to be processed is generated by the plasma. A plasma processing method for plasma processing, wherein electromagnetic waves are transmitted through an electromagnetic wave transmission path of a wall of the processing container, and electromagnetic waves are radiated inside the processing container by an electromagnetic wave radiation portion electromagnetically coupled to the electromagnetic wave transmission path. By radiating toward the surface, it can be suitably used when performing a plasma processing method for generating plasma inside the processing container.

  A plasma processing method according to a twenty-fourth aspect of the present invention uses a plasma processing apparatus according to any one of the first to thirty-third aspects, and does not break a vacuum between plasma oxidation and film formation by a plasma CVD method. Do it continuously.

  According to this plasma processing method, after the object to be processed is oxidized, the film forming process can be performed without being exposed to the atmosphere. Therefore, the interface between the object to be processed and the film can be a good interface with little contamination, and a film with good quality can be formed on the object to be processed. Further, both processes can be performed by the same apparatus, and the footprint can be reduced and the apparatus can be manufactured at low cost.

Hereinafter, a first embodiment of the present invention will be described with reference to FIGS.
The plasma processing apparatus 1 shown in FIGS. 1 to 4 is oscillated by a high-frequency power source 2 as an electromagnetic wave source, transmitted through an electromagnetic wave transmission path 3, and radiated into a vacuum vessel 4 as a processing container. Plasma is generated in the vacuum vessel 4 and the object to be processed 5 is subjected to plasma processing by this plasma.

  As shown in FIGS. 2 and 3, the vacuum container 4 includes a container body 11 and a lid 12. The container body 11 has a bottom wall 11a and a peripheral wall 11b and is open upward. The lid 12 covers the container body 11 from above so as to close the opening of the container body 11. That is, the vacuum container 4 includes the bottom wall 11a and the peripheral wall 11b of the container body 11 and the lid 12 as walls. The container body 11 and the lid 12 are kept airtight by an O-ring 13.

  The vacuum vessel 4 has a processing chamber 4a for plasma processing the object 5 to be processed. The processing chamber 4a is defined by a wall that the vacuum vessel 4 has. In other words, the processing chamber 4 a is defined by the inner surface of the bottom wall 11 a and the inner surface of the peripheral wall 11 b and the inner surface of the lid 12 of the container body 11.

  The vacuum container 4 is formed with such a strength that the inside of the processing chamber 4a can be depressurized to a vacuum state or the vicinity thereof. As a material for forming the vacuum vessel 4, for example, a metal material such as aluminum can be used. As will be described later, a metal slot plate 14 as an electromagnetic wave radiation portion and a covering dielectric member 16 covering the slot plate 14 are provided in the processing chamber 4a. A support base 17 that supports the object to be processed 5 is provided in the processing chamber 4 a of the vacuum vessel 4.

  The vacuum container 4 has a gas inlet 18 for introducing a process gas into the processing chamber 4a and a gas exhaust port 19 for exhausting the gas in the processing chamber 4a. Further, the inside of the processing chamber 4 a is communicated with a vacuum exhaust system (not shown) through a gas exhaust port 19. As the vacuum exhaust system, for example, a turbo molecular pump can be used. Therefore, by operating this vacuum exhaust system, the inside of the processing chamber 4a can be exhausted until a predetermined degree of vacuum is reached.

  The electromagnetic wave transmission path 3 is for transmitting electromagnetic waves, and has, for example, one rectangular waveguide 21 for electromagnetic wave distribution and three rectangular waveguides 22 for electromagnetic wave radiation. . Of the walls of the vacuum vessel 4, a wall that defines the processing chamber 4 a, for example, the lid 12 has a part of each rectangular waveguide 22 for electromagnetic wave radiation. That is, a part of the rectangular waveguide 22 for electromagnetic wave radiation and the wall constituting the vacuum vessel 4 are integrated. In other words, a part of the tube wall conductor of each rectangular waveguide 22 for electromagnetic wave radiation also serves as a wall constituting the vacuum vessel 4.

  Specifically, the inner surface of the lid 12 has three groove-like recesses 23 that are part of three rectangular waveguides 22 for electromagnetic wave radiation. These recesses 23 are covered by the slot plate 14 from the processing chamber 4a side. By doing so, three rectangular waveguides 22 for electromagnetic wave radiation are constituted by the three spaces surrounded by the wall surfaces defining the three recesses 23 and the slot plate 14.

  The slot plate 14 is formed of a metal plate material and has a plurality of slots 15a that radiate electromagnetic waves into the processing chamber 4a. These slots 15 a are formed at positions corresponding to the recesses 23. Specifically, the slots 15a are arranged in a checkered pattern, that is, alternately arranged on a pair of virtual lines parallel to each other, thereby forming one slot group 15. In one slot group 15, the vertical pitch and the horizontal pitch between the slots 15a are uniform. The slot plate 14 is provided with three slot groups 15 so as to correspond to the three recesses 23, respectively.

  A coating dielectric member 16 is provided in the processing chamber 4 a so as to cover the slot plate 14. The covering dielectric member 16 can be formed of a dielectric material such as quartz, alumina, and fluororesin, for example. In order to prevent the electromagnetic wave from propagating in the thickness direction of the covering dielectric member 16, the covering dielectric member 16 is ¼ of the wavelength of the electromagnetic wave in the covering dielectric member 16. It is preferable to set a smaller value.

  As shown in FIGS. 2 and 3, the slot plate 14 and the dielectric member 16 for clothing are screwed to the lid 12 of the vacuum vessel 4 from the inner surface side by a male screw 24 as a fixture. In the case where a metal screw is used as the male screw 24, if the head of the male screw 24 is exposed to the processing chamber 4a, electromagnetic waves may be disturbed near the head of the male screw 24. Therefore, in the case where a metal screw is used as the male screw 24, its head is preferably covered with the dielectric cap 25. By doing in this way, disturbance of electromagnetic waves generated near the head of the male screw 24 can be suppressed.

As shown in FIG. 4, the cross-sectional shape of each recess 23 has a horizontally long rectangular shape in which the length x ₁ in the depth direction is shorter than the length x ₂ in the width direction. That is, in the electromagnetic wave radiation rectangular waveguide 22 formed in this way, the bottom surface of the recess 23 and the top surface of the slot plate 14 are surfaces (H surfaces) perpendicular to the electric field direction of the electromagnetic wave. The surface that rises vertically downward from the bottom surface is a surface parallel to the electric field direction of the electromagnetic wave (E surface). That is, in the present embodiment, the slot 15a is provided on the H surface of each rectangular waveguide 22 for electromagnetic wave radiation.

The cross-sectional shape of each recess 23, may be formed long longitudinal rectangular shape than the depth direction of the length x ₁ of the width direction length x _2. In the rectangular waveguide 22 for electromagnetic wave radiation formed in this way, the bottom surface of the recess 23 and the top surface of the slot plate 14 become E planes parallel to the electric field direction of the electromagnetic wave, and downward from the bottom surface of the recess 23. The surface that rises perpendicularly to H is the H plane perpendicular to the electric field direction of the electromagnetic wave. Therefore, by doing in this way, it can comprise so that the slot 15a may be provided in E surface of each rectangular waveguide 22 for electromagnetic wave radiation.

The inner cross-sectional dimensions of these rectangular waveguides 22 for radiating electromagnetic waves are set to sizes that allow the frequency of electromagnetic waves to be transmitted in the fundamental mode in the rectangular waveguide. In the present embodiment, when the dielectric constant of the rectangular waveguide 22 for electromagnetic wave radiation is ε, the major axis of the inner cross-sectional dimension of the rectangular waveguide is x ₂ = a, and the wavelength λ of the electromagnetic wave,
(Λ / ε ^0.5 ) <2a (1)
Designed to meet the requirements of In the present embodiment, the dielectric constant in the rectangular waveguide 22 for electromagnetic wave radiation is equal to the dielectric constant of air, and ε = 1.

  Further, these rectangular waveguides 22 for electromagnetic wave radiation are arranged in parallel to each other so that the distance d is 50 cm or less. More specifically, the position of the rectangular waveguide 22 for electromagnetic wave radiation is set as follows.

That is, the angular frequency of the electromagnetic wave emitted from the high-frequency power source 2 is ω, the dielectric constant of the covering dielectric member 16 is ε _d , the speed of light is c, the electron charge is e, the dielectric constant of vacuum is ε ₀ , the electron density the _{n e,} when the electron mass and _{m e,} plasma angular frequency omega _P is
ω _P = (e ² × n _e / (ε ₀ × m _e )) ^0.5 (2)
And the wave number k is
k = ω / c ((ε _d (ω _p ² −ω ² )) / (ω _p ² − (1 + ε _d ) ω ² )) ^0.5 (3)
Is required.

With respect to the internal dimension L in the direction in which the wave number k is orthogonal to each rectangular waveguide of the vacuum vessel 4,
k = mπ / L (m is an integer of 1 ≦ m ≦ 2L / (λ / ε ^0.5 )) (4)
The distance d between the rectangular waveguides 22 for electromagnetic wave radiation is
λ _swp = π / k (5)
It is _{set as} the space _| interval of wavelength (lambda) _swp of the standing wave guide _{| induced} by. Moreover, the rectangular waveguide 22 for electromagnetic wave radiation is disposed at a position where the amplitude of the standing wave is substantially maximized.

  Each of the rectangular waveguides 22 for radiating electromagnetic waves is coupled to the high frequency power source 2 via an electromagnetic wave distributing rectangular waveguide 21 for distributing the electromagnetic waves to the rectangular waveguides 22.

  As the high frequency power source 2, for example, a power source that supplies an electromagnetic wave having a frequency of 10 MHz to 25 GHz to the electromagnetic wave transmission line 3 can be used. In the present embodiment, as the high frequency power source 2, one microwave source that supplies an electromagnetic wave having a frequency of 2.45 GHz ± 50 MHz to the electromagnetic wave transmission path 3 is employed. The high frequency power supply 2 having a frequency of 2.45 GHz is preferable because it is mass-produced, is inexpensive, and has a wide variety of types.

  The rectangular waveguide 21 for electromagnetic wave distribution is connected to the lid 12 of the vacuum vessel 4 and is configured integrally with the wall of the vacuum vessel 4. Specifically, the rectangular waveguide 21 for electromagnetic wave distribution is provided outside the vacuum vessel 4. The electromagnetic wave distribution rectangular waveguide 21 is bent at a right angle so that the propagation direction of the electromagnetic wave is changed by 90 ° from the tube main body 21a orthogonal to the respective rectangular waveguides 22 for radiation of electromagnetic waves. It has three distribution pipe portions 21b, and is formed so as to distribute the electromagnetic waves whose propagation directions are changed by 90 ° to the respective rectangular waveguides 22 for electromagnetic wave radiation.

  Further, the cross-sectional shape of the rectangular waveguide 21 for electromagnetic wave distribution has a rectangular shape in which the length x1 in the depth direction is longer than the length x2 in the width direction. In the present embodiment, the rectangular waveguide 21 for electromagnetic wave distribution is formed in the same size as the rectangular waveguide 22 for electromagnetic wave radiation. That is, in this rectangular waveguide 21 for electromagnetic wave distribution, the bottom surface and the upper surface are surfaces (H surfaces) perpendicular to the electric field direction of the electromagnetic wave, and the pair of side surfaces facing each other are in the electric field direction of the electromagnetic wave. It becomes a parallel surface (E surface).

  In the present embodiment, the three rectangular waveguides 22 for radiating electromagnetic waves and the rectangular waveguide 21 for distributing electromagnetic waves are arranged substantially on the same plane, and the rectangular waveguide for distributing electromagnetic waves. Electromagnetic waves are distributed from the E surface of the tube 21 to the rectangular waveguides 22 for electromagnetic wave radiation. The electromagnetic wave transmission path 3 may be configured such that each of the electromagnetic wave radiation rectangular waveguides 22 branches from the H plane of the electromagnetic wave distribution rectangular waveguide 21.

  The rectangular waveguide 21 for electromagnetic wave distribution is coupled to the respective rectangular waveguides 22 for electromagnetic wave radiation as follows. The recess 23 provided in the lid 12 of the vacuum vessel 4 is also opened on the peripheral surface of the lid 12. The electromagnetic wave distributing rectangular waveguide 21 is communicated with each of the electromagnetic wave distributing rectangular waveguides 21 through the opening on the peripheral surface of the lid 12. Airtightness is maintained by an O-ring 27 between the tip of the rectangular waveguide 21 for electromagnetic wave distribution and the peripheral surface of the lid 12 (the outer surface of the vacuum vessel 4).

  Thus, in this plasma processing apparatus 1, a plurality of (three in this embodiment) rectangular waveguides for electromagnetic wave radiation are supplied from one high-frequency power supply 2 through the rectangular waveguides 21 for electromagnetic wave distribution. Electromagnetic waves are supplied to 22. Therefore, since the frequency can be made the same throughout the electromagnetic wave transmission path 3, it is easy to design an antenna (slot plate 14) that radiates a uniform energy density.

  A cooling pipe 28 as a cooling mechanism is provided in a region corresponding to a space between adjacent slots 15a in the wall of the vacuum vessel 4. In the cooling pipe 28, a coolant as a refrigerant is circulated. By doing so, the electromagnetic wave transmission path 3 (the rectangular waveguide 22 for electromagnetic wave radiation) can be efficiently cooled by the refrigerant without disturbing the generation of plasma.

  As described above, according to this plasma processing apparatus 1, the lid 12 as the wall of the vacuum vessel 4 has the rectangular waveguide 22 for electromagnetic wave radiation that is at least a part of the electromagnetic wave transmission path 3 that transmits the electromagnetic wave. Therefore, the structure can be simplified, and the plasma treatment can be satisfactorily performed even for the object 5 such as a square substrate or a large-area substrate.

  In addition, according to the plasma processing apparatus 1, the electromagnetic wave transmission window can be omitted, and the sealing portion for holding the vacuum of the vacuum container 4 is used as the rectangular waveguide 21 for electromagnetic wave distribution and the vacuum container 4. It is possible to have two places, namely, a connecting part for connecting the lid 12 and a connecting part for connecting the lid 12 and the container main body 11. Therefore, as compared with the conventional plasma processing container in which the electromagnetic wave transmitting window is provided in the vacuum container 4, the structure can be made simple and the manufacturing cost can be reduced.

Hereinafter, a second embodiment of the present invention will be described with reference to FIGS.
In the plasma processing apparatus 1 of this embodiment, the dielectric member 31 for the electromagnetic wave transmission path is located in the region located in the vacuum vessel 4 in the electromagnetic wave transmission path 3, that is, in the rectangular waveguide 22 for electromagnetic wave radiation. Is provided. The dielectric member 31 for the electromagnetic wave transmission line can be formed of, for example, synthetic quartz, alumina, fluororesin, or the like. In the present embodiment, the dielectric member 31 for the electromagnetic wave transmission path is formed of synthetic quartz.

  When the dielectric member 31 for electromagnetic wave transmission is provided in the rectangular waveguide 22 for electromagnetic wave radiation, as shown in FIGS. 8A and 8B, the dielectric member 31 for electromagnetic wave transmission is formed in advance. It can be realized by fitting into the rectangular waveguide 22 for electromagnetic wave emission. Thereafter, the slot plate 14 and the covering dielectric member 16 may be laminated on the inner surface of the lid 12 in this order, and fixed to the lid 12 with the fixture 26. In the present embodiment, the slot plate 14 and the covering dielectric member 16 are fixed to the lid 12 of the vacuum vessel 4 by a fixture (for example, male screw) 26 made of a dielectric material.

  By the way, when the electromagnetic wave radiation rectangular waveguide 22 is filled with the electromagnetic wave transmission path dielectric member 31, the size (inner cross-sectional dimension) of the electromagnetic wave radiation rectangular waveguide 22 is set to the dielectric for the electromagnetic wave transmission path. The body member 31 needs to be sized so that the frequency of the electromagnetic wave can be transmitted in the fundamental mode in the rectangular waveguide. In other words, the rectangular waveguide 22 for electromagnetic wave emission according to the present embodiment has an inner cross-sectional dimension (major axis) of a rectangular waveguide formed in such a size that the frequency of the electromagnetic wave can be transmitted in the fundamental mode in the rectangular waveguide in the air. And the minor axis) must be divided by the square root of the dielectric constant of the dielectric member 31 in the electromagnetic wave transmission path 3. Specifically, since synthetic quartz has a dielectric constant ε of about 4, the electromagnetic wave radiation rectangular waveguide 22 of this embodiment transmits the frequency of electromagnetic waves in the fundamental mode in the rectangular waveguide in the air. For a rectangular waveguide formed in a possible size, the major axis and the minor axis need to be about ½ each.

  On the other hand, since the inside of the rectangular waveguide 21 for electromagnetic wave distribution is filled with air, the tube main body 21a of the rectangular waveguide 21 for electromagnetic wave distribution has a fundamental frequency within the rectangular waveguide in which the frequency of electromagnetic waves is in air. It is necessary to make the size that can be transmitted in the mode (same as the size of the tube body 21a of the first embodiment). Therefore, in the plasma processing apparatus 1 of the present embodiment, the three distribution pipe portions 21b are tapered so that the electromagnetic wave distribution rectangular waveguide 21 and the electromagnetic wave emission rectangular waveguide 22 are connected. ing.

  In the plasma processing apparatus 1, a dielectric member 32 for holding the vacuum vessel 4 in an airtight manner is provided in the electromagnetic wave transmission path 3, for example, in the distribution pipe portion 21 b of the rectangular waveguide 21 for electromagnetic wave distribution. The dielectric member 32 is configured to maintain the airtightness of the vacuum vessel 4. The dielectric member 32 for holding the vacuum vessel 4 in an airtight manner may be provided in the electromagnetic wave transmission path 3 and may be provided, for example, in the rectangular waveguide 22 for electromagnetic wave emission. In this case, the dielectric member 31 may also have the function.

  The distance between the rectangular waveguide 21 for electromagnetic wave distribution and the dielectric member 32 for holding the vacuum vessel 4 in an airtight manner is set to 1 mm. Further, the O-ring 33 keeps the airtightness between the inner surface of the electromagnetic wave distribution rectangular waveguide 21 and the dielectric member 32 for keeping the vacuum vessel 4 airtight. The electromagnetic wave is introduced from the outside of the vacuum container 4 into the vacuum container 4 through the dielectric member 32 for keeping the vacuum container 4 airtight. In the present embodiment, the dielectric member 32 for holding the vacuum vessel 4 in an airtight manner and the dielectric member 31 in the electromagnetic wave transmission path 3 are integrally molded, but in order to hold the vacuum vessel 4 in an airtight manner. The dielectric member 32 and the dielectric member 31 in the electromagnetic wave transmission path 3 may be separated. Since other configurations are the same as those of the first embodiment described above including a portion not shown, overlapping descriptions will be omitted by attaching the same reference numerals to the drawings.

  If this plasma processing apparatus 1 is used, the to-be-processed object 5 can be plasma-oxidized on surface wave plasma conditions, for example. Further, if this plasma processing apparatus 1 is used, for example, a plasma film can be formed on the object 5 under surface wave plasma conditions. Furthermore, if this plasma processing apparatus 1 is used, the to-be-processed object 5 can be plasma-etched on surface wave plasma conditions. Moreover, if this plasma processing apparatus 1 is used, plasma oxidation and film formation by plasma CVD can be performed continuously without breaking the vacuum. Hereinafter, as an example of a plasma processing method for the object 5 to be processed, a plasma processing method in which plasma oxidation and film formation by the plasma CVD method are performed without breaking the vacuum will be described.

  For example, a silicon substrate is prepared as the object 5 to be processed. The object to be processed 5 is provided on a support base 17 in the vacuum vessel 4. An evacuation system is operated and the air in the vacuum vessel 4 (inside the processing chamber 4a) is discharged. Thereafter, the first gas is supplied into the vacuum container 4 through the gas inlet 18. As the first gas, for example, oxygen gas or a mixed gas of oxygen and a rare gas containing at least one of helium, neon, argon, krypton, and xenon is used. In the present embodiment, oxygen gas is employed as the first gas, and this gas is supplied into the vacuum vessel 4 so that the oxygen gas is 400 SCCM and the total pressure is 20 Pa.

  After the gas pressure in the vacuum container 4 reaches a predetermined gas pressure, irradiation with electromagnetic waves is started. The electromagnetic wave sent to the slot 15a via the electromagnetic wave transmission path 3 is radiated into the vacuum container 4 from each slot 15a.

  The electromagnetic wave radiated into the vacuum vessel 4 excites oxygen gas as the first gas. When the electron density in the plasma in the vicinity of the dielectric member 16 to be coated increases to a certain extent, the electromagnetic wave cannot propagate in the plasma and attenuates in the plasma. Therefore, the electromagnetic wave does not reach the area away from the clothing dielectric member 16, and surface wave plasma is generated in the vicinity of the clothing dielectric member 16.

  In the state where the surface wave plasma is generated, a high electron density is achieved in the vicinity of the dielectric member 16 to be coated, and accordingly, high-density oxygen atom active species are generated. This high-density oxygen atom active species diffuses to the object 5 to be processed, and the object 5 is efficiently oxidized. As a result, a first insulating film is formed on the surface of the object 5 to be processed. In the state in which surface wave plasma is generated, the electron temperature in the vicinity of the surface of the object to be processed 5 is low (electron energy is low), so the electric field of the sheath in the vicinity of the surface of the object to be processed 5 is also weak. Accordingly, since the incident energy of ions to the object to be processed 5 is reduced, ion damage of the object to be processed 5 during the oxidation process is suppressed.

  Further, the second gas is supplied from the gas inlet 18 into the vacuum container 4. As the second gas, for example, silane, an organic silicon compound (tetraalkoxysilane, vinylalkoxysilane, alkyltrialkoxysilane, phenyltrialkoxysilane, polymethyldisiloxane, polymethylcyclotetrasiloxane, etc.), or an organic metal A gas containing a compound (trimethylaluminum, triethylaluminum, tetrapropoxyzirconium, pentaethoxytantalum, tetrapropoxyhafnium, or the like) can be used. In the present embodiment, oxygen gas is continuously used as the first gas, and tetraethoxysilane gas, which is a kind of tetraalkoxysilane, is used as the second gas. Then, these gases are supplied into the vacuum vessel 4 so that the oxygen gas as the first gas is 400 SCCM, the tetraethoxysilane gas as the second gas is 10 SCCM, and the total pressure is 20 Pa.

  Oxygen radicals generated from the first gas react with tetraethoxysilane as the second gas. Thereby, decomposition of tetraethoxysilane is promoted, and silicon oxide is deposited on the surface of the object 5 to be processed. As a result, a second insulating film (silicon oxide film formed by CVD) is formed on the first insulating film. Thus, the formation of the insulating film on the object 5 is completed. According to this plasma processing method, after the object 5 is oxidized, the film forming process can be performed without exposure to the atmosphere. Therefore, the interface between the object to be processed and the film can be a good interface with little contamination, and a CVD film with good quality can be formed on the object to be processed 5.

  As described above, according to the plasma processing apparatus 1, similarly to the first embodiment, the lid 12 as the wall of the vacuum vessel 4 is an electromagnetic wave radiation that is at least part of the electromagnetic wave transmission path 3 that transmits the electromagnetic wave. Since the rectangular waveguide 22 is provided, the structure can be simplified and the plasma processing can be satisfactorily performed even on the object to be processed 5 such as a rectangular substrate or a large-area substrate. Can do.

  In addition, according to the plasma processing apparatus 1, the electromagnetic wave transmission window can be omitted, and the sealing portion for holding the vacuum of the vacuum container 4 is used as the rectangular waveguide 21 for electromagnetic wave distribution and the vacuum container 4. It is possible to have two places, namely, a connecting part for connecting the lid 12 and a connecting part for connecting the lid 12 and the container main body 11. Therefore, as compared with the conventional plasma processing container in which the electromagnetic wave transmitting window is provided in the vacuum container 4, the structure can be made simple and the manufacturing cost can be reduced.

  Furthermore, according to the plasma processing apparatus 1 of this embodiment, the to-be-processed object 5 can be plasma-processed by surface wave plasma. Further, since the rectangular waveguide 22 for electromagnetic wave radiation has the dielectric member 31 for the electromagnetic wave transmission path, the plasma generated in the vacuum vessel 4 is prevented from entering the electromagnetic wave transmission path 3. can do.

Hereinafter, a third embodiment of the present invention will be described with reference to FIGS.
In the plasma processing apparatus 1 of this embodiment, the dielectric member 31 for the electromagnetic wave transmission path is located in the region located in the vacuum vessel 4 in the electromagnetic wave transmission path 3, that is, in the rectangular waveguide 22 for electromagnetic wave radiation. Is provided. The dielectric member 31 for the electromagnetic wave transmission line can be formed of, for example, synthetic quartz, alumina, fluororesin, or the like. In the present embodiment, the dielectric member 31 for the electromagnetic wave transmission path is formed of a fluororesin. Since the fluororesin is lighter than the synthetic quartz (having a lower specific gravity), the plasma processing apparatus 1 can be reduced in weight by forming the dielectric member 31 for the electromagnetic wave transmission path with the fluororesin.

  By the way, in this embodiment, the inside of the rectangular waveguide 22 for electromagnetic wave radiation is filled with a fluororesin. Since the fluororesin has a dielectric constant smaller than that of synthetic quartz, it is not necessary to reduce the size of the rectangular waveguide 22 for electromagnetic wave emission as in the second embodiment. Therefore, in this embodiment, the inner cross-sectional dimension of the rectangular waveguide 22 for electromagnetic wave radiation is the same as the inner cross-sectional dimension of the rectangular waveguide 21 for electromagnetic wave distribution.

  Further, in order to suppress reflection of electromagnetic waves at the interface between the rectangular waveguide 22 for electromagnetic wave radiation and the slot 15a and the interface between the slot 15a and the dielectric member 16, a dielectric member 34 is provided in the slot 15a. ing. The dielectric member 34 can be formed of, for example, synthetic quartz, alumina, fluorine resin, or the like. In the present embodiment, the dielectric member 34 is formed of a fluororesin. When the covering dielectric member 16 is made of synthetic quartz, some electromagnetic waves are reflected at the interface between the slot 15a and the dielectric member 16, but the slot dielectric member 34 is omitted ( Compared to the state in which the inside of the slot 15a is filled with air), the reflection at the interface between the slot 15a and the dielectric member 16 can be reduced by providing the dielectric member 34 for the slot.

  When the dielectric member 31 is provided in the rectangular waveguide 22 for electromagnetic wave radiation, the dielectric member 31 is formed in advance in the rectangular waveguide 22 for electromagnetic wave radiation, as in the second embodiment. It can be realized by fitting it into. Thereafter, the slot plate 14 in which the dielectric member 34 is fitted in the slot 15a and the dielectric member 16 for covering may be laminated on the inner surface of the lid 12 in this order, and fixed to the lid 12 with the fixture 26. In the present embodiment, the slot plate 14 and the covering dielectric member 16 are fixed to the lid 12 of the vacuum vessel 4 by a fixture 26 made of a dielectric material.

  The dielectric member 31 in the electromagnetic wave transmission path 3 and the dielectric member 34 in the slot may be assembled together. By doing so, it is possible to save the trouble of packing the dielectric members 34 one by one in the slot 15a. Alternatively, the dielectric member 31 in the electromagnetic wave transmission path 3, the dielectric member 34 in the slot, and the dielectric member 16 for covering may be assembled together.

  In the plasma processing apparatus 1, an airtight container separate from the dielectric member 31 for the electromagnetic wave transmission path is provided in the electromagnetic wave transmission path 3, for example, the distribution pipe portion 21 b of the rectangular waveguide 21 for electromagnetic wave distribution. A dielectric member 32 is provided for holding the gas container 4 in an airtight manner, and the dielectric member 32 is configured to maintain the airtightness of the vacuum vessel 4. The dielectric member 32 can be made of, for example, synthetic quartz, fluororesin, or alumina. Airtightness is maintained by an O-ring 33 between the inner surface of the rectangular waveguide 21 for electromagnetic wave distribution and the dielectric member 32 for keeping the airtight container 4 airtight.

  Note that the plasma processing method using the surface wave plasma as described in the second embodiment can also be realized by using the plasma processing apparatus 1 of the present embodiment. Since other configurations are the same as those of the second embodiment described above including a portion not shown, overlapping descriptions are omitted by attaching the same reference numerals to the drawings.

  As described above, according to the plasma processing apparatus 1, similarly to the first embodiment, the lid 12 as the wall of the vacuum vessel 4 is an electromagnetic wave radiation that is at least part of the electromagnetic wave transmission path 3 that transmits the electromagnetic wave. Since the rectangular waveguide 22 is provided, the structure can be simplified and the plasma processing can be satisfactorily performed even on the object to be processed 5 such as a rectangular substrate or a large-area substrate. Can do.

  In addition, according to the plasma processing apparatus 1, the electromagnetic wave transmission window can be omitted, and the sealing portion for holding the vacuum of the vacuum container 4 is used as the rectangular waveguide 21 for electromagnetic wave distribution and the vacuum container 4. It is possible to have two places, namely, a connecting part for connecting the lid 12 and a connecting part for connecting the lid 12 and the container main body 11. Therefore, as compared with the conventional plasma processing container in which the electromagnetic wave transmitting window is provided in the vacuum container 4, the structure can be made simple and the manufacturing cost can be reduced.

  Furthermore, according to the plasma processing apparatus 1 of this embodiment, the to-be-processed object 5 can be plasma-processed by surface wave plasma.

  Further, since the dielectric member 34 is provided in the slot 15a, the reflection of electromagnetic waves at the interface between the rectangular waveguide 22 for electromagnetic wave radiation and the slot 15a, and the slot 15a and the dielectric member 16 for covering are provided. The reflection of electromagnetic waves at the interface can be suppressed.

  A dielectric member 31 in the electromagnetic wave transmission path 3, a dielectric member 34 in the slot, a dielectric member 16 for coating, and a dielectric member 32 for holding the hermetic container 4 as a processing container in an airtight manner. The dielectric material to be formed is not limited to synthetic quartz, fluororesin, alumina or the like, and various dielectric materials can be used.

  The plasma processing apparatus and the plasma processing method of the present invention are not limited to the above-described embodiments, and can be implemented in various ways without departing from the gist thereof.

1 is a top view showing a plasma processing apparatus according to a first embodiment of the present invention. Sectional drawing which follows the II-II line | wire in FIG. Sectional drawing which follows the III-III line in FIG. FIG. 2 is a perspective view showing a part of the vacuum vessel of the plasma processing apparatus of FIG. The top view which shows the plasma processing apparatus which concerns on the 2nd Embodiment of this invention. Sectional drawing which follows the VI-VI line in FIG. Sectional drawing which follows the VII-VII line in FIG. (A) (B) is a manufacturing process figure which shows the process of forming the lid | cover with which the plasma processing apparatus of FIG. 5 is provided. The figure which shows the plasma processing apparatus which concerns on the 3rd Embodiment of this invention in cross section along the rectangular waveguide direction for electromagnetic wave radiation. The figure which shows the plasma processing apparatus of FIG. 9 in cross section along the direction which crosses the rectangular waveguide for electromagnetic wave radiation. The figure which shows the relationship between the distance from a particle generation point, and particle density. The figure which shows typically the standing wave of m = 1 in a vacuum vessel. The figure which shows typically the standing wave of m = 2L / ((lambda) / (epsilon) ^0.5 ) in a vacuum vessel.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Plasma processing apparatus, 2 ... High frequency power supply (electromagnetic wave source), 3 ... Electromagnetic wave transmission path, 4 ... Vacuum container (processing container), 14 ... Electromagnetic radiation part (slot board), 15a ... Slot, 16 ... Dielectric for coating Body member, 21 ... rectangular waveguide for electromagnetic wave distribution, 22 ... rectangular waveguide for electromagnetic wave radiation, 26 ... fixture, 31 ... dielectric member, 32 ... dielectric member, 34 ... dielectric member

Claims (24)

A plasma processing apparatus for generating plasma in the processing container by electromagnetic waves radiated from an electromagnetic wave radiating portion in the processing container, and performing plasma processing by the plasma,
The plasma processing apparatus, wherein the wall of the processing container has at least a part of an electromagnetic wave transmission path for transmitting electromagnetic waves. An electromagnetic wave transmission path for transmitting electromagnetic waves;
An electromagnetic wave radiation part for electromagnetic wave radiation coupled to the electromagnetic wave transmission path;
A processing container,
A plasma processing apparatus for generating plasma in the processing container by electromagnetic waves radiated into the processing container from the electromagnetic wave radiating unit, and performing plasma processing by the plasma;
A plasma processing apparatus, wherein at least a part of the electromagnetic wave transmission path and a wall constituting the processing container are integrated. An electromagnetic wave transmission path for transmitting electromagnetic waves;
An electromagnetic wave radiation part for electromagnetic wave radiation coupled to the electromagnetic wave transmission path;
A processing container,
A plasma processing apparatus for generating plasma in the processing container by electromagnetic waves radiated into the processing container from the electromagnetic wave radiating unit, and performing plasma processing by the plasma;
At least a part of the tube wall conductor forming the electromagnetic wave transmission path also serves as a wall constituting the processing container. A dielectric member is provided in the electromagnetic wave transmission path, and the hermeticity of the processing container is maintained by the dielectric member,
The plasma processing apparatus according to any one of claims 1 to 3, wherein the electromagnetic wave is introduced from the outside of the processing container into the processing container through the dielectric member.   5. The plasma processing apparatus according to claim 1, wherein a dielectric member is provided in at least a part of a region located in the processing container in the electromagnetic wave transmission path. 6. .   The electromagnetic wave radiation portion is a slot plate having a plurality of slots. The slot plate is provided in the processing container, and a covering dielectric member is provided to cover the slot plate. The plasma processing apparatus according to any one of claims 1 to 5, wherein:   The plasma processing apparatus according to claim 6, wherein a dielectric member is provided in the slot.   The electromagnetic wave transmission path has a plurality of rectangular waveguides for electromagnetic wave radiation, and the plurality of slots are provided corresponding to the E-plane or H-plane of the rectangular waveguides for electromagnetic wave radiation, respectively. The plasma processing apparatus according to claim 6, wherein the apparatus is a plasma processing apparatus. The inner cross-sectional dimensions of the plurality of rectangular waveguides for electromagnetic wave radiation are set to sizes at which the frequency of electromagnetic waves can be transmitted in the fundamental mode in the rectangular waveguide,
9. The plasma processing apparatus according to claim 8, wherein the rectangular waveguides for electromagnetic wave radiation are arranged in parallel to each other, and the interval is set to 50 cm or less. Assuming that the dielectric constant of the rectangular waveguide for electromagnetic wave radiation is ε, the major axis of the inner cross-sectional dimension of the rectangular waveguide for electromagnetic wave radiation is a with respect to the wavelength λ of the electromagnetic wave.
(Λ / ε ^0.5 ) <2a
In relation to
The angular frequency of the electromagnetic wave is ω, the dielectric constant of the dielectric material for coating is ε _d , the speed of light is c, the charge amount of electrons is e, the dielectric constant of vacuum is ε ₀ , the electron density is _ne , and the mass of electrons the when and m _e, these and plasma angular frequency ω _P
ω _P = (e ² × n _e / (ε ₀ × m _e )) ^0.5
Wave number k defined by
k = ω / c ((ε _d (ω _p ² −ω ² )) / (ω _p ² − (1 + ε _d ) ω ² )) ^0.5
Is the internal dimension L in the direction orthogonal to the rectangular waveguide for electromagnetic wave radiation of the processing container,
k = mπ / L (m is an integer of 1 ≦ m ≦ 2L / (λ / ε ^0.5 ))
In relation to
These rectangular waveguides for electromagnetic radiation are:
λ _swp = π / k
The plasma processing apparatus according to claim 9, wherein the plasma processing apparatus is disposed at a position where the amplitude of the standing wave is substantially _{maximized at} an interval of the wavelength λ _swp of the standing wave guided by.   A dielectric member is provided in at least a part of a region located in the processing container in the electromagnetic wave transmission path, and a dielectric member is provided in the slot. The plasma processing apparatus according to claim 6, wherein the dielectric member and the dielectric member in the slot have substantially the same dielectric constant in the frequency band of electromagnetic waves.   The plasma processing apparatus according to claim 5 or 11, wherein the dielectric member for the electromagnetic wave transmission path is made of at least one of quartz, alumina, and fluororesin. The electromagnetic wave source further includes an electromagnetic wave source, and the electromagnetic wave transmission path includes an electromagnetic wave distributing waveguide for distributing the electromagnetic wave generated by the electromagnetic wave source to the plurality of rectangular waveguides for electromagnetic wave radiation. And
A dielectric member is provided in the electromagnetic wave transmission path, and the hermeticity of the processing container is maintained by the dielectric member,
9. The plasma processing apparatus according to claim 8, wherein electromagnetic waves are introduced into the processing container from outside the processing container through the dielectric member.   The plasma processing apparatus according to claim 13, wherein the plurality of rectangular waveguides for electromagnetic wave radiation are provided so as to branch from an E surface or an H surface of the electromagnetic wave distribution waveguide. .   The electromagnetic wave distribution waveguide is bent at a right angle so that the propagation direction of the electromagnetic wave is changed by 90 °, and the electromagnetic wave whose propagation direction is changed by 90 ° is applied to the plurality of rectangular waveguides for electromagnetic wave emission. The plasma processing apparatus according to claim 13, wherein the plasma processing apparatus is formed so as to be distributed.   The plurality of electromagnetic wave radiation rectangular waveguides are provided so as to be branched from the E surface of the electromagnetic wave distribution waveguide, and the plurality of electromagnetic wave radiation square waveguides and the electromagnetic wave distribution waveguides. The plasma processing apparatus according to claim 14, wherein the waveguide is disposed on substantially the same plane. A dielectric member is provided in at least a part of a region located in the processing container in the electromagnetic wave transmission path, a dielectric member is provided in the slot, and
The plasma processing apparatus according to claim 6, wherein the dielectric member in the electromagnetic wave transmission path, the dielectric member in the slot, and the dielectric member for covering are assembled together.   The plasma processing apparatus according to claim 6, wherein the covering dielectric member is fixed by a fixing member made of a dielectric material.   The covering dielectric member is formed in a plate shape covering the slot plate, and the thickness thereof is set to be smaller than ¼ of the wavelength of the electromagnetic wave in the covering dielectric member. The plasma processing apparatus according to claim 6.   6. The distance between the electromagnetic wave transmission path and a dielectric member for holding the processing container in an airtight manner or a dielectric member in the electromagnetic wave transmission path is set to 1 mm or less. The plasma processing apparatus according to 1.   The plasma processing apparatus according to claim 1, further comprising an electromagnetic wave source that supplies an electromagnetic wave having a frequency of 10 MHz to 25 GHz to the electromagnetic wave transmission line.   The plasma processing apparatus according to claim 21, wherein the electromagnetic wave source supplies an electromagnetic wave having a frequency of 2.45 GHz ± 50 MHz to the electromagnetic wave transmission path.   The plasma processing apparatus according to any one of claims 1 to 22, wherein plasma oxidation, plasma film formation, or plasma etching is performed under surface wave plasma conditions.   24. A plasma processing method, wherein plasma oxidation and film formation by plasma CVD are continuously performed using the plasma processing apparatus according to claim 1 without breaking a vacuum.

Images