JP2006040609A - Plasma treatment device and method, and manufacturing method for flat panel display apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To avoid a complicatedness and an enlargement of a device construction with an antenna array consisting of a plurality of wave guide slot antennas, whose opening is enlarged. <P>SOLUTION: A distributor 30 is equipped with a wave guide for feeding which extends in a direction of widths of the wave guide slot antennas 10A to 10H, and has openings 12 formed on a surface of a wall of the wave guide for feeding, through which wave guides for radiation having the wave guide slot antennas 10A to 10H communicate with the wave guide for feeding. Since the distributor 30 uses the wave guide for feeding of the length same as a summation of widths of the wave guides for radiation having the wave guide slot antennas 10A to 10H, the device construction is not complicated and enlarged even if the opening of the antenna array is enlarged by increasing a number of the wave guide slot antennas which constitute the antenna array. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a plasma processing apparatus and method, and more particularly to a plasma processing apparatus and method for processing an object to be processed such as a flat panel display using plasma generated by microwaves.

  In the manufacture of flat panel display devices such as LCD (liquid crystal display), plasma processing devices are widely used to perform processes such as etching, ashing, and CVD (Chemical Vapor Deposition). As one of plasma processing apparatuses, there is a microwave plasma processing apparatus that generates plasma by ionizing or exciting a gas in a processing container by supplying a microwave into the processing container. A microwave plasma processing apparatus that uses a planar antenna having a circular radiation surface, such as a radial line slot antenna, as a microwave supply means has been put into practical use. Currently, development of a microwave plasma processing apparatus using a planar antenna having a rectangular radiation surface is underway. One of them uses an antenna array composed of a plurality of waveguide slot antennas.

FIG. 29 is a longitudinal sectional view showing the overall configuration of a conventional plasma processing apparatus using a waveguide slot antenna array. FIG. 30 is a cross-sectional view of a part of the configuration including the waveguide slot antenna array. In these drawings, a part of the configuration is shown as functional blocks.
The conventional plasma processing apparatus shown in FIG. 29 has a bottomed cylindrical processing container 1 having a square shape in plan view. The processing container 1 is made of a metal such as Al. A mounting table 2 is disposed at the center of the bottom surface of the processing container 1. On the top surface of the mounting table 2, an LCD substrate 3 or the like is disposed as an object to be processed. A high frequency power source 5 is connected to the mounting table 2 via a matching box 4.

An exhaust port 6 for vacuum exhaust is provided at the peripheral edge of the bottom surface of the processing container 1, and a gas introduction port 7 for introducing gas into the processing container 1 is provided on the side wall of the processing container 1. For example, when the plasma processing apparatus is used as an etching apparatus, a plasma gas such as Ar and a reactive gas such as CF ₄ are introduced.
The upper opening of the processing container 1 is closed with a dielectric plate 8 made of quartz glass or the like so as not to leak the plasma generated in the processing container 1 while introducing microwaves therefrom. Note that an O-ring is interposed between the upper surface of the side wall of the processing container 1 and the dielectric plate 8 to ensure airtightness in the processing container 1.
A waveguide slot antenna array 910 is disposed above the dielectric plate 8. The outer peripheries of the dielectric plate 8 and the antenna array 910 are covered with a shield material 9 disposed in an annular shape on the side wall of the processing container 1, and microwaves supplied from the antenna array 910 into the processing container 1 leak to the outside. It has no structure.

The output side of the microwave distributor 930 is connected to the introduction portion of the waveguide slot antenna array 910, and the microwave oscillator 42 is connected to the input side of the microwave distributor 930 via the microwave waveguide 41. .
As shown in FIG. 30, the waveguide slot antenna array 910 includes a plurality of waveguide slot antennas 910A, 910B, 910C, and 910D. The waveguide slot antennas 910 </ b> A to 910 </ b> D are antennas in which a plurality of radiating slots 911 are formed on the H-plane (wide side wall parallel to the magnetic field) of a radiating waveguide made of a rectangular waveguide. One end of the radiating waveguide is open and the other end is short-circuited. The waveguide slot antennas 910A to 910D have a width orthogonal to the axial direction of the radiation waveguide in a state where the H surface of the radiation waveguide in which the slot 911 is formed is opposed to the mounting table 2. Aligned in the direction.

  The microwave distributor 930 includes an introduction portion 931 having the same width as the microwave waveguide 41, a branch portion 932 that is bifurcated from the tip of the introduction portion 931, and extends in an oblique direction, and each tip of the branch portion 932. The parallel portion 933 extending in parallel to the axial direction of the radiating waveguide of the waveguide slot antennas 910A to 910D and the total width of the radiating waveguides of the waveguide slot antennas 910A to 910D have the same width. And a dividing portion 934. A stub 935 is provided at the center of the boundary between the introduction portion 931 and the branch portion 932. The dividing portion 934 is partitioned in the center in the width direction by a partition plate 936 extending in the axial direction of the radiating waveguide.

  In the plasma processing apparatus having such a configuration, when the microwave oscillator 42 is driven, the microwave is introduced into the introduction portion 931 of the microwave distributor 930 through the microwave waveguide 41. The phase of the microwave introduced into the introduction unit 931 is adjusted by the stub 935, divided into two by the branching unit 932, reaches the division unit 934 through the parallel unit 933, and each of the waveguide slot antennas 910A to 910D. Introduced into the radiating waveguide. The microwaves introduced into the radiating waveguide are gradually radiated from a plurality of slots 911 formed on the H plane while propagating through the tube, and are transmitted through the dielectric plate 8 and supplied into the processing container 1. . Electrons are accelerated by the microwave electric field supplied into the processing chamber 1, and the gas in the processing chamber 1 is ionized, excited, and dissociated to generate reactive species. By this reactive species, the surface of the LCD substrate 3 on the mounting table 2 is subjected to a process such as etching.

  By using an antenna array 910 including a plurality of waveguide slot antennas 910 </ b> A to 910 </ b> D as in this plasma processing apparatus, microwaves are supplied to a wide area inside the processing container 1 that is rectangular in plan view to generate plasma. be able to. Further, since the microwave distributor 930 is symmetric with respect to the center line C parallel to the axial direction of the radiating waveguide of the waveguide slot antennas 910A to 910D, the microwave distributor 930 is also symmetric to the plurality of waveguide slot antennas 910A to 910D. The microwaves from the microwave oscillator 42 can be distributed with the same phase and the same power (see, for example, Patent Document 1).

The applicant has not yet found prior art documents related to the present invention by the time of filing other than the prior art documents specified by the prior art document information described in this specification.
JP-A-11-111493

  In order to reduce the manufacturing cost of a flat panel display device, it has been desired to realize a plasma processing apparatus capable of processing a large substrate. In order to process a larger substrate than before, a processing container having a larger diameter than before is required, and the opening area of the planar antenna for supplying microwaves to the processing container must be increased according to the diameter of the processing container. Don't be.

In the case where the antenna array including the plurality of waveguide slot antennas described above is used as the planar antenna, a method of increasing the cross-sectional size of the radiating waveguide of the waveguide slot antenna can be considered to increase the aperture area. However, if the long side of the cross section of the radiating waveguide exceeds the guide wavelength, the TE ₀₁ mode is excited in addition to the TE ₁₀ mode, making it difficult to control the microwave.
On the other hand, in the method in which the waveguide slot antennas are arranged apart from each other and the surface wave is excited in the dielectric plate 8 by the microwaves radiated from each of the waveguide slot antennas, this surface wave is a standing wave mode. Therefore, the electric field distribution is non-uniform, and the distribution of plasma excited by the electric field is also non-uniform. In addition, since the electric field component in the direction perpendicular to the plasma surface is large, microwaves are easily absorbed by the plasma, and the electron temperature increases, causing substrate damage and metal contamination due to sputtering of the processing vessel 1.

Therefore, in order to increase the opening area, it is preferable to increase the number of waveguide slot antennas constituting the antenna array. However, in this case, when the microwave is distributed to the radiating waveguide of each waveguide slot antenna in the same manner as the microwave distributor 930 used in the conventional plasma processing apparatus, the branch portion having two branches A large number of 932s are required, and the configuration of the microwave distributor is complicated and large. In addition, when the number of waveguide slot antennas is other than 2 ⁿ (n is an integer of 2 or more), the microwave distributor having the branching portion 932 cannot be used, and the design flexibility of the device configuration is small. There was a problem.

  In addition, in order to perform plasma processing using a processing container having a larger diameter than before, it is necessary to supply large power to the processing container in accordance with an increase in the space in which plasma is generated. However, since the price of the microwave oscillator 42 is remarkably increased when the output power is increased, there is a problem that the manufacturing cost of the entire plasma processing apparatus is significantly increased due to the price of the microwave oscillator 42.

  Further, the electric field intensity in the processing container 1 is stronger as it is closer to the slot 911 for supplying the microwave, and the plasma generation is promoted as the electric field intensity is stronger. Therefore, the plasma density distribution in the processing container 1 is near the slot 911. It tends to be higher. In order to make the plasma density distribution more uniform, the interval between the slots 911 arranged in the axial direction of the radiating waveguide of the waveguide slot antennas 910A to 910D may be reduced. However, if the slots 911 are not arranged at a predetermined interval based on the in-tube wavelength of the radiating waveguide, there is a problem that the interval between the slots 911 cannot be reduced unnecessarily because the microwave radiation direction changes. .

The present invention has been made to solve such problems, and its object is to increase the complexity and size of the apparatus configuration when increasing the opening area of an antenna array composed of a plurality of waveguide slot antennas. The purpose is to increase the degree of freedom in designing the device configuration.
Another object is to suppress the manufacturing cost of the plasma processing apparatus.
Another object is to make the plasma density distribution in the processing vessel uniform.

In order to achieve such an object, in the plasma processing apparatus of the present invention, a slot is formed in a mounting table for mounting an object to be processed, a processing container for storing the mounting table, and a radiation waveguide. A plurality of waveguide slot antennas are arranged in the width direction orthogonal to the axial direction of the radiating waveguide and are arranged opposite to the mounting table, and connected to one end of the radiating waveguide, respectively. A distributor for distributing microwaves, and the distributor includes a feeding waveguide extending in a width direction of the waveguide slot antenna, and a radiating waveguide formed on a wall surface of the feeding waveguide. And an opening for communicating with the power feeding waveguide.
In this distributor, a feeding waveguide having the same length (length in the axial direction) as the sum of the widths of the radiation waveguides of all the waveguide slot antennas may be used, so that an antenna array is configured. Even if the number of waveguide slot antennas is increased and the opening area is increased, the apparatus configuration is not complicated and enlarged as compared with the conventional microwave distributor 930. Further, even when the number of waveguide slot antennas is other than 2 ⁿ , it can be dealt with only by adjusting the length of the feeding waveguide.

In this plasma processing apparatus, a slot may be formed on a wall surface facing the mounting table of the power feeding waveguide. Thereby, a waveguide slot antenna antenna is constituted by the feeding waveguide.
The distributor further has a guide wall that projects from the wall surface of the power supply waveguide facing the opening toward the opening and guides the microwave propagating through the power supply waveguide to the radiation waveguide. It may be.
The antenna arrays may be provided on both sides of the power feeding waveguide.

In addition, this plasma processing apparatus may include a slow wave material made of a dielectric material disposed only in the tube of the radiation waveguide. By arranging the slow wave material in the tube of the radiation waveguide, the relative dielectric constant in the tube of the radiation waveguide becomes larger than 1, and the wavelength in the tube of the radiation waveguide becomes short. Since the slots of the radiating waveguide are arranged at a predetermined interval based on the wavelength in the tube, the shorter the wavelength in the tube, the shorter the slot interval, so that more slots can be provided in the radiating waveguide of the same length. It becomes possible to form. Therefore, microwaves with lower power than in the prior art are supplied into the processing container at shorter intervals than in the past, so that the plasma density distribution is made uniform. In addition, since the slow wave material is not disposed in the tube of the power supply waveguide and is left hollow, it is not necessary to reduce the diameter of the power supply waveguide and reduce the power supply.
Here, the slow wave material may have a gradient at an end portion on one end side of the radiation waveguide. As a result, the change in dielectric constant at the boundary between the radiation waveguide and the power feeding waveguide becomes gentle, and the reflection of microwaves at this boundary is reduced.

Further, in the above-described plasma processing apparatus, the width of the radiation waveguide is set to approximately ½ of the in-tube wavelength of the power supply waveguide, and the opening formed in the wall surface of the power supply waveguide is defined as the power supply guide. Two radiating waveguides that are adjacent to each other through one opening may be communicated with the feeding waveguide by being arranged at substantially the same interval as the wavelength within the wave tube. As a result, the microwaves are introduced from the feeding waveguide to each of the radiating waveguides in the same phase.
Also, two conductor plates arranged substantially parallel to each other, and a partition member made of a conductor extending between the two conductor plates and partitioning a space formed by the two conductor plates, A radiation waveguide and a power feeding waveguide may be formed from the conductor plate and the partition member.

The above-described plasma processing apparatus includes a microwave oscillator that generates a microwave, a microwave waveguide that guides the microwave output from the microwave oscillator to a power supply waveguide, and the microwave waveguide. And an impedance matching unit that matches the impedance between the power supply side and the load side. By matching the impedance, the reflection of the microwave at the connecting portion between the microwave waveguide and the feeding waveguide is suppressed.
Here, the impedance matching unit may be configured by an iris provided in the vicinity of a connection portion between the power feeding waveguide and the microwave waveguide and narrowing the pipeline of the microwave waveguide.

The plasma processing apparatus described above may include a plurality of microwave supply apparatuses including an antenna array, a distributor, and a microwave oscillator that supplies a microwave to the distributor. Thereby, a low output microwave oscillator can be used.
Here, the two microwave supply devices are arranged so that the other ends of the radiation waveguides of the two microwave supply devices are opposite to each other and the slots formed in the radiation waveguides of the two microwave supply devices are aligned on the same straight line. May be. Thereby, the regularity of slot arrangement is maintained.
Moreover, the dielectric plate which closes the antenna array side edge part of a processing container, and the reinforcement member extended so that it may oppose the boundary of several adjacent antenna arrays and supporting a dielectric plate may be provided. .

In the above-described plasma apparatus, the number of slots formed in the radiation waveguide may be different depending on the position where the radiation waveguide is disposed in the antenna array.
For example, the slot may be formed only in a region excluding the central portion of the surface facing the mounting table formed by combining all the radiation waveguides. Thereby, since a microwave is not supplied from the central part of the surface facing the mounting table, plasma generation in the upper space of the central part of the mounting table is suppressed. Usually, since plasma tends to be high density in the upper space of the central portion of the mounting table, the plasma density distribution is made uniform by suppressing the plasma generation in this space.
Here, the distributor may supply a smaller power to the radiation waveguide having a smaller number of slots. As a result, in a radiating waveguide having a small number of slots, power loss that is not radiated from the slots is reduced.

  In the plasma processing apparatus described above, the waveguide slot antenna may supply circularly polarized waves from the slot to the inside of the processing container. As a result, the electric field rotates in a plane parallel to the plane in which the slot of the radiating waveguide is formed, so that a uniform plasma is generated on the average in time. A waveguide slot antenna and a distributor may supply circularly polarized waves from the slot to the inside of the processing container.

  The plasma processing method of the present invention also includes an antenna array in which a plurality of waveguide slot antennas each having a slot formed in a radiation waveguide are arranged in the width direction perpendicular to the axial direction of the radiation waveguide. A plasma processing method of using a plasma generated by a microwave supplied into a processing container and processing a target object on a mounting table accommodated in the processing container by using the microwave supplied into the processing container , The microwaves are supplied to the power supply waveguides constituting the distributor, and the microwaves are supplied to each of the radiation waveguides through the openings formed in the side walls of the power supply waveguides. The microwave is supplied into the processing container through a slot formed in the waveguide for use.

In this plasma processing method, a slow wave material made of a dielectric may be disposed only in the radiation waveguide, and a plurality of slots formed in the radiation waveguide may be shortened.
In addition, two conductor plates are arranged substantially parallel to each other, and a space formed by the two conductor plates is partitioned by a partition member made of a conductor extending between the two conductor plates, and the two conductor plates are separated from each other. A radiation waveguide and a power feeding waveguide may be formed from the members.

A plurality of microwave supply devices including an antenna array, a distributor, and a microwave oscillator for supplying a microwave to the distributor may be used.
Alternatively, the slot may be formed only in a region excluding the central portion of the surface facing the mounting table formed by combining all the radiation waveguides.
Further, the antenna array is arranged outside the processing container, the antenna array side end of the processing container is closed with a dielectric plate, and the temperature of the antenna array is controlled with the antenna array in contact with the dielectric plate. It may be.

  The flat panel display device manufacturing method of the present invention is characterized in that at least one of etching, ashing, and CVD is performed on an object to be processed using the above-described plasma processing method.

As described above, in the present invention, the feeding waveguide extending in the direction in which the waveguide slot antenna for supplying microwaves into the processing container is arranged and arranged, and the radiating waveguide of the waveguide slot antenna And an increase in the number of waveguide slot antennas constituting the antenna array to increase the area of the opening, thereby increasing the size and size of the apparatus. The degree of freedom in designing the device configuration can be increased.
Further, by forming the slot on the wall surface facing the mounting table of the power feeding waveguide, a member having the function of only the distributor is not required, so that the apparatus configuration can be further simplified and miniaturized.

  Further, by arranging the slow wave material in the tube of the radiation waveguide, more slots can be formed in the radiation waveguide of the same length than the conventional one. As a result, microwaves with lower power than the conventional ones are supplied into the processing container at shorter intervals than before, so that the plasma distribution can be made uniform. Further, by leaving the inside of the feeding waveguide tube hollow, it is not necessary to reduce the diameter of the feeding waveguide and to reduce the supply power. Therefore, the number of waveguide slot antennas to which the distributor can distribute microwaves does not change, and the design flexibility of the device configuration is not limited.

Further, the width of the radiation waveguide is set to be approximately ½ of the in-tube wavelength of the power supply waveguide, and the opening formed in the wall surface of the power supply waveguide is approximately equal to the in-tube wavelength of the power supply waveguide. Since the microwaves are introduced in the same phase from the feeding waveguide to each of the radiating waveguides by arranging them at the same interval, the slot arrangement should be the same for all waveguide slot antennas. Can do.
Further, by forming a radiation waveguide and a power feeding waveguide from two conductor plates arranged substantially parallel to each other and a partition member that partitions a space formed by these two conductor plates, It becomes easy to cover the opening of the processing container with the antenna.
In addition, by providing an impedance matching device in the microwave waveguide that guides the microwave output from the microwave oscillator to the power supply waveguide, the microwave at the connection between the microwave waveguide and the power supply waveguide is provided. Therefore, the microwave can be efficiently introduced into the power supply waveguide.

In addition, by providing a plurality of microwave supply devices including an antenna array, a distributor, and a microwave oscillator, a low-output microwave oscillator can be used. Since the price of the microwave oscillator increases as the output power increases, the manufacturing cost of the entire plasma processing apparatus can be reduced by using a plurality of microwave oscillators with low output and low price.
In addition, a dielectric plate that closes the antenna array side end of the processing container and a reinforcing member that supports the dielectric plate are provided, and the reinforcing member is extended so as to be opposed to the boundaries of the adjacent antenna arrays. Thus, since the microwave is not radiated from the boundary of the antenna array, the influence of the reinforcing member on the microwave can be reduced.

In addition, in the upper space of the central portion of the mounting table having a high plasma density, a slot is formed only in a region excluding the central portion of the surface facing the mounting table formed by combining all the radiation waveguides. Since plasma generation is suppressed, the plasma density distribution can be made uniform.
Here, by supplying a smaller power to a radiation waveguide having a smaller number of slots, the loss of power not radiated from the slots in the radiation waveguide having a smaller number of slots is reduced, and plasma is efficiently generated. be able to.

In addition, by supplying circularly polarized waves from the slot to the inside of the processing container, the electric field rotates in a plane parallel to the plane on which the slot is formed, and thus a uniform plasma is generated on the average in time. . Therefore, by arranging the object to be processed in parallel with the surface on which the slot is formed, the surface of the object to be processed can be uniformly processed.
Further, the temperature of the dielectric plate can be adjusted by controlling the temperature of the antenna array while the antenna array is in contact with the dielectric plate that closes the end of the processing container. For example, by cooling the antenna array, it is possible to prevent the dielectric plate from being damaged by the plasma heat flow. Further, heating the antenna array can prevent deposition on the dielectric plate.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In the following drawings, components corresponding to those shown in FIGS. 29 and 30 are denoted by the same reference numerals as those in FIGS. 29 and 30, and description thereof will be omitted as appropriate.

(First embodiment)
FIG. 1 is a longitudinal sectional view showing the overall configuration of the plasma processing apparatus according to the first embodiment of the present invention. FIG. 2 is a cross-sectional view of a part of the configuration of the plasma processing apparatus shown in FIG. In these drawings, some components are shown as functional blocks.
The plasma processing apparatus shown in FIG. 1 includes a mounting table 2 on which an LCD substrate 3 or the like is mounted as an object to be processed, a bottomed cylindrical processing container 1 having a square shape in which the mounting table 2 is accommodated, and a processing container 1. And a microwave supply device 50 for supplying microwaves from the outside into the processing container 1 via the dielectric plate 8. Here, the microwave supply device 50 includes a waveguide slot antenna array 10, a microwave distributor 30, a microwave waveguide 41, and a microwave oscillator 42.

  As shown in FIG. 2, the waveguide slot antenna array 10 includes a plurality of waveguide slot antennas 10A, 10B, 10C, 10D, 10E, 10F, 10G, and 10H. The waveguide slot antennas 10A to 10H are antennas in which a plurality of radiating slots 11 are formed on the H surface of a radiating waveguide made of a rectangular waveguide. A power feeding slot (opening) 12 is formed at one end of the radiation waveguide, and the other end is short-circuited. In such a waveguide slot antenna 10A to 10H, with the H surface of the radiation waveguide in which the radiation slot 11 is formed facing the mounting table 2, the axial direction of the radiation waveguide (micro Are aligned in the width direction perpendicular to the wave traveling direction).

A slow wave material 21 made of a dielectric is disposed in the waveguide slot antenna of the waveguide slot antennas 10A to 10H. If the relative permittivity of the slow wave material 21 is εr (> 1) and the in-tube wavelength when the inside of the radiation waveguide is hollow is λg ₀ , the in-tube wavelength λg when the slow wave material 21 is arranged is
λg = λg ₀ / (εr) ^1/2 (1)
It becomes. Note that the end of the slow wave member 21 on the side where the power supply slot 12 is provided is formed with a gradient 21A so that the thickness gradually changes.
A microwave absorber 22 is also arranged in the vicinity of the short-circuited other end in the radiation waveguide. The microwave absorber 22 is not always necessary.

  As the radiation slot 11, a cross slot that radiates circularly polarized waves is used. The cross slot has a configuration in which two slots forming a pair intersect each other at the center, and the magnitude of the electric field radiated from each slot is equal, the phase is 90 ° different, and the polarization directions are orthogonal. Be placed. For example, when the relative dielectric constant εr in the radiating waveguide is 3.6, the lengths of the two slots are 2.94 cm and 3.19 cm, respectively, and the two slots intersect with each other at substantially right angles, It is arranged so as to be inclined at approximately 45 ° with respect to the axis of the radiation waveguide. Alternatively, the lengths of the two slots are 2.80 cm and 3.83 cm, respectively, and the two slots cross each other at an angle of about 107 °, and are about 36.5 with respect to the axis of the radiation waveguide. It may be arranged so as to be inclined. In the present embodiment, the plurality of radiating slots 11 composed of such cross slots are arranged on one side with respect to the central axis of the radiating waveguide at intervals of a natural number multiple of approximately λg.

  Further, the microwave distributor 30 has a plurality of power supply slots (openings) 12 formed on the E surface (narrow side wall parallel to the electric field) of a power supply waveguide made of a rectangular waveguide. The feeding waveguide has the same length as the total sum of the widths (lengths in the width direction) of the radiating waveguides of the waveguide slot antennas 10A to 10H. A plurality of feeding slots 12 formed on the E surface of the feeding waveguide and a feeding slot 12 formed at one end of the radiating waveguide are arranged so as to overlap each other. The waveguide for radiation and the waveguide for radiation communicate with each other. The feeding slot 12 is adjusted so that the microwaves are evenly supplied to all the radiating waveguides.

In the power feeding waveguide, an opening 31 is formed at the center of the E surface facing the E surface where the power feeding slot 12 is formed. A microwave oscillator 42 with an oscillation frequency of, for example, 2.45 GHz is connected to the opening 31 via a microwave waveguide 41 made of a rectangular waveguide. In the tube of the microwave waveguide 41, an iris 43 is provided in the vicinity of the connection portion with the power supply waveguide (for example, a position separated from the central axis of the power supply waveguide by about 1/4 of the tube wavelength). Yes. The iris 43 is a wall that protrudes vertically from the left and right side walls of the microwave waveguide 41, and by adjusting the width of the pipeline of the microwave waveguide 41, the power supply side and the load side of the microwave waveguide 41 Can be matched.
In addition, in the tube of the power supply waveguide, a guide wall 32 projecting vertically from the E surface where the opening 31 is formed toward the center in the width direction of the power supply slot 12 extends between the upper and lower H surfaces. Exist. The protruding length of the guide wall 32 is about 1/5 of the width of the power supply waveguide. A slow wave material is not disposed in the tube of the power supply waveguide, and is hollow.

Incidentally, the guide wavelength of the feeding waveguide When lambda] g _0, the width of the radiation waveguide is formed in a substantially λg _0/2. Therefore, feeding slot 12 is also formed in a substantially lambda] g _0/2 intervals. Therefore, the microwaves are supplied in phase opposite to each other from the feeding waveguide through the feeding slot 12 to the adjacent radiating waveguide. Therefore, the radiating slots 11 of the adjacent waveguide slot antennas radiate the waveguide so that circularly polarized waves in the same rotational direction are radiated from all the radiating slots 11 of the waveguide slot antennas 10A to 10H. It is arranged at a position shifted by approximately λg / 2 in the axial direction of the tube.

In the present embodiment, the radiation waveguides of the waveguide slot antennas 10A to 10H and the feeding waveguide of the microwave distributor 30 are two pieces of a square in plan view arranged in parallel and spaced apart from each other. the interior of the box body comprising a side wall 15, 16, 17, 18 which connects the periphery of flat plate 13 and flat plate 13, the side wall 15 at a position spaced from the side wall 15 by substantially lambda] g _0/2, 17 in parallel with the partition in the partition plate 19 disposed, the partition plate 19 and the region sandwiched between the side wall 17, substantially in the seven partition plates 20 disposed parallel to the side walls 16,18 λg _0/2 Formed by partitioning at intervals. In addition, the flat plates 13 and 14, the side walls 15 to 18, and the partition plates 19 and 20 are formed of a conductor such as copper.

  In this case, the flat plates 13 and 14 are the H surfaces of all the radiation waveguides and the feeding waveguide, the side wall 15 is one E surface of the feeding waveguide, and the partition plate 19 is the feeding waveguide. The other E face of the tube and one end face of all the radiating waveguides, the side wall 17 becomes the other end face of all the radiating waveguides, and a part of each of the side walls 16 and 18 of the feeding waveguide. Both end surfaces are formed, and the other portions of the side walls 16 and 18 and the partition plate 20 are the E surfaces of the radiation waveguide. An opening 31 is formed in the central portion of the side wall 15, and a plurality of power supply slots 12 are formed in the partition plate 19. A plurality of radiation slots 11 are formed on the flat plate 14 facing the mounting table 2.

In the plasma processing apparatus configured as described above, when the microwave oscillator 42 is driven, the microwave is supplied from the opening 31 of the microwave distributor 30 through the microwave waveguide 41 to the power supply waveguide of the microwave distributor 30. Introduced in the pipe. Since the iris 43 is provided in the tube of the microwave waveguide 41 and impedance matching is achieved, the reflection of the microwave at the connecting portion between the microwave waveguide 41 and the feeding waveguide is suppressed.
The microwave introduced into the tube from the center of the power supply waveguide is bifurcated and propagates toward both end faces of the power supply waveguide. Then, it induced in the guide wall 32 disposed at substantially lambda] g _0/2 intervals in the traveling direction of the microwave, feeding slot 12 of waveguide slot antennas 10A~10H through opposing the guide wall 32 Evenly distributed to each radiating waveguide.

The microwaves introduced into the radiating waveguide are gradually radiated from a plurality of radiating slots 11 formed on the H surface while propagating through the dielectric plate 8 while propagating through the tube in which the slow wave material 21 is disposed. Then, it is supplied into the processing container 1. The microwave remaining without being emitted from the radiation slot 11 is absorbed by the microwave absorber 22.
Electrons are accelerated by the microwave electric field supplied into the processing chamber 1, and the gas in the processing chamber 1 is ionized, excited, and dissociated to generate reactive species. By this reactive species, the surface of the LCD substrate 3 on the mounting table 2 is subjected to a process such as etching.

As described above, in this embodiment, the microwave distribution having a configuration in which a plurality of power supply slots 12 are formed on the E surface of the power supply waveguide extending in the direction in which the waveguide slot antennas 10A to 10H are arranged and arranged. A vessel 30 is used. Even if the number of waveguide slot antennas is increased in order to increase the opening area, the distributor 30 is used for feeding a power having the same length as the total width of the radiation waveguides of all the waveguide slot antennas. Since it is only necessary to use a waveguide, the apparatus configuration is not as complicated and large as the conventional microwave distributor 930. Further, even when the number of waveguide slot antennas is other than 2 ⁿ , it can be dealt with only by adjusting the length of the feeding waveguide. Therefore, it is possible to suppress the complexity and increase in size of the device configuration when the number of waveguide slot antennas is increased to increase the opening area, and it is possible to increase the degree of design freedom of the device configuration.

In this embodiment, since it is not necessary to increase the cross-sectional size of the radiating waveguide of the waveguide slot antenna in order to increase the opening area, a single-mode microwave waveguide is used as the radiating waveguide. A tube can be used, and microwave control becomes easy.
Further, since it is not necessary to excite surface waves in the dielectric plate 8, the plasma distribution can be made uniform. Further, since microwaves are radiated from the slot surfaces of the waveguide slot antennas 10A to 10H in a substantially vertical direction and the electric field component in the direction perpendicular to the plasma surface is small, the substrate damage and the metal contamination in the processing container 1 are low. Electron temperature plasma can be realized.

Further, by arranging the iris 43 in the tube of the microwave waveguide 41 and matching the impedance between the power supply side and the load side of the microwave waveguide 41, the microwave waveguide 41 and the power supply waveguide are connected. The reflection of the microwave at the connecting portion is suppressed, and the microwave can be efficiently introduced into the power feeding waveguide.
In addition, an induction wall 32 is provided in the tube of the power feeding waveguide of the microwave distributor 30, and the microwave propagating through the power feeding waveguide is guided to the waveguide slot antennas 10 </ b> A to 10 </ b> H via the power feeding slot 12. By guiding to the radiation waveguide, it is possible to efficiently supply the microwave from the power supply waveguide to the radiation waveguide whose axis direction is orthogonal.

  Further, by arranging the slow wave material 21 in the waveguide of the waveguide slot antennas 10A to 10H, the wavelength of the waveguide of the radiation waveguide is shortened, and the radiation set based on the wavelength of the waveguide is set. The interval between the slots 11 for use is also shortened. For this reason, more radiation slots 11 can be formed in the radiation waveguide of the same length than when the inside of the tube is hollow. Therefore, it is possible to supply microwaves with a lower power at shorter intervals in the processing container 1 than in the case where the inside of the tube is hollow, so that the plasma density distribution can be made uniform.

In addition, by forming a gradient 21A at the end of the slow wave member 21 on the side where the feeding slot 12 is present, the dielectric constant from the air to the dielectric at the boundary between the feeding waveguide and the radiating waveguide is increased. The change becomes gradual and the reflection of microwaves at this boundary is reduced. Therefore, the microwave can be efficiently supplied to the radiation waveguide.
In this case, the slow wave material is not arranged in the tube of the power supply waveguide of the microwave distributor 30 and is left hollow, thereby reducing the diameter of the power supply waveguide and reducing the power supply. There is no need to do. Therefore, the number of waveguide slot antennas to which the distributor 30 can distribute microwaves does not change, and the design flexibility of the device configuration is not limited.

Further, by forming a cross slot as the radiating slot 11 and radiating circularly polarized waves into the processing container 1, a plane parallel to the H plane on which the radiating slots 11 of the waveguide slot antennas 10A to 10H are formed. In this plane, a uniform plasma is generated on a time average basis. Therefore, by disposing the LCD substrate 3 in parallel with the H surface on which the radiation slot 11 is formed, the surface of the LCD substrate 3 can be uniformly processed.
Note that, like the microwave supply device 150 shown in FIG. 3, a C-shaped slot may be used as the radiation slot 111 that radiates circularly polarized waves. The C-shaped slot has a configuration in which the extension line of one slot intersects the other slot or its extension line, and the magnitude of the electric field radiated from each slot is equal and the phase is 90 ° different. It arrange | positions so that a polarization direction may be orthogonal.

  Further, in the present embodiment, an example in which the opening 31 and the feeding slot 12 are formed on the E surface of the feeding waveguide of the microwave distributor 30 is shown, but the opening is formed on the H surface of the feeding waveguide. There is also a microwave distributor in which a feeding slot is formed. This distributor is used corresponding to a waveguide slot antenna in which a plurality of radiation slots are formed on the E-plane of the radiation waveguide.

(Second Embodiment)
The plasma processing apparatus according to the second embodiment of the present invention uses a microwave distributor that distributes microwaves in the same phase to all the radiation waveguides of the waveguide slot antenna array.
FIG. 4 is a cross-sectional view of a microwave supply apparatus including the microwave distributor. In this figure, components corresponding to the components shown in FIG. 2 are denoted by the same reference numerals as in FIG. 2, and some components are denoted by functional blocks.

The microwave distributor 230 included in the microwave supply device 250 shown in FIG. 4 supplies microwaves to the radiation waveguides of the waveguide slot antennas 210A, 210B, 210C, 210D, 210E, 210F, 210G, and 210H. A plurality of openings 212 are formed at intervals of approximately λg _{0 on} the E surface (partition plate 219) of the feeding waveguide made of a rectangular waveguide. Note that λg ₀ is the in-tube wavelength of the power feeding waveguide. Since the width of the radiation waveguide is a substantially lambda] g _0/2, is formed in two boundary regions of the radiation waveguide adjacent the aperture 212, respectively, the two radiating waveguide adjacent at one opening 212 The tube communicates with the power supply waveguide.

In the feeding waveguide, an opening 31 is formed at the center of the E surface opposite to the E surface where the opening 212 is formed. A microwave oscillator is connected to the opening 31 via a microwave waveguide 41. 42 is connected. Note that the opening 31 may be formed at a position opposite to a portion where the opening 212 is not formed in the boundary region between two adjacent radiating waveguides. Further, the opening 31 may be formed on the end face of the power feeding waveguide.
In addition, a plurality of guide walls 232 projecting vertically from the E surface in which the opening 31 is formed toward the center in the width direction of the opening 212 are disposed in the tube of the power feeding waveguide. The interval between the guide walls 232 is also substantially λg ₀ as in the case of the opening 212.

It should be noted that the inside of the feeding waveguide is hollow, the length of the feeding waveguide is the same as the total width of the radiating waveguides of the waveguide slot antennas 210A to 210H, and the opening 212. Is adjusted so that the microwaves are uniformly supplied to all the radiation waveguides, which is the same as the plasma distributor 30 shown in FIGS.
On the other hand, in the waveguide slot antennas 210 </ b> A to 210 </ b> H, in order to facilitate introduction of microwaves into two adjacent radiating waveguides, an E plane (partition plate 220) serving as a boundary between the two radiating waveguides. ) On the opening 212 side is slightly retracted.

  With this configuration, the microwaves are introduced in the same phase from the feeding waveguide of the microwave distributor 230 to each of the radiating waveguides of the waveguide slot antennas 210A to 210H. The arrangement of the slots 11 can be the same for all the waveguide slot antennas 210A to 210H.

(Third embodiment)
The plasma processing apparatus according to the third embodiment of the present invention uses a microwave supply apparatus in which a distribution of microwave supply power is distributed in a plane in which slots of a waveguide slot antenna array are formed. is there.
FIG. 5 is a cross-sectional view of the microwave supply device. In this figure, constituent elements corresponding to the constituent elements shown in FIG. 2 or FIG. 4 are indicated by the same reference numerals as those in FIG. 2 or FIG. 4, and some constituent elements are indicated by functional blocks.

  A microwave supply device 350 shown in FIG. 5 is substantially the same as the microwave supply device 250 in the second embodiment. However, in the present embodiment, the arrangement and number of the radiating slots 11 of the waveguide slot antennas 310A, 310B, 310C, 310D, 310E, 310F, 310G, and 310H constituting the antenna array 310 are the same as the waveguide. The slot antennas 310 </ b> A to 310 </ b> H differ depending on the positions where they are arranged in the antenna array 310. More specifically, the radiating slot 11 is not arranged in the central portion 360 of the surface facing the mounting table 2 formed by combining the waveguide slot antennas 310A to 310H, and only the region excluding the central portion 360 is included. The radiating slot 11 is disposed in Here, the portion 360 where the radiation slot 11 is not disposed faces the central portion of the mounting table 2.

  The plasma density distribution in the processing container 1 tends to be higher in the upper space of the central portion of the mounting table 2 when the plasma reaches a steady state. If the slot 11 is not disposed in the portion 360 facing the central portion of the mounting table 2, microwaves are not emitted to the upper space of the central portion of the mounting table 2 having a high plasma density, so that plasma generation in this space is suppressed. The Therefore, the plasma density distribution can be made uniform.

As described above, when the number of the radiating slots 11 is different for each waveguide slot antenna, if the power is evenly distributed to the radiating waveguides of all the waveguide slot antennas, the number of the radiating slots 11 is reduced. In a small number of radiation waveguides, the power that is not radiated from the radiation slot 11 and is finally absorbed by the microwave absorber 22 increases. For this reason, the distribution amount of the microwave distributor 230 is adjusted, and the smaller the number of the radiation slots 11 is, the smaller the power is supplied to the radiation waveguide. As a result, loss of power not radiated from the radiating slot 11 can be reduced, and plasma can be generated efficiently. Here, the distribution amount of the microwave distributor 230 depends on the size of the opening 212 for supplying the microwave to the radiation waveguide and the guide wall 232 for guiding the microwave to the radiation waveguide through the opening 212. It can be adjusted by the protrusion length.
Note that the shape of the portion 360 where the slot 11 is not disposed may be a square shape or a circular shape.

(Fourth embodiment)
The plasma processing apparatus according to the fourth embodiment of the present invention uses a combination of a plurality of microwave supply apparatuses.
FIG. 6 is a diagram illustrating a configuration example in the case where a plurality of microwave supply devices are used in combination. In this figure, (a) shows a surface on which a slot for radiating a waveguide slot antenna array is formed, and (b) shows a cross-sectional configuration in the VIb-VIb ′ line direction in (a). In addition, the component equivalent to the component shown in FIG. 2 or FIG. 4 is shown with the same code | symbol as FIG. 2 or FIG.

  When a plurality of microwave supply devices 250A, 250B, 250C, 250D, 250E, and 250F are used in combination, the surface of the waveguide slot antenna array 210 on which the radiation slot 11 is formed needs to be continuous. Therefore, as shown in FIG. 6A, the microwave supply devices 250A, 250B, and 250C are arranged so that the side walls 16 and 18 of the antenna array 210 face each other. The same applies to the microwave supply devices 250D, 250E, and 250F. Further, the microwave supply devices 250A and 250D are arranged so that the side walls 17 of the antenna array 210 face each other. The same applies to the microwave supply devices 250B and 250E and 250C and 250F.

  When the radiating slots 11 are formed in a line in the axial direction of the radiating waveguide, the microwave supply devices 250A and 250D are arranged so that the radiating slots 11 are aligned on the same straight line. . The same applies to the microwave supply devices 250B and 250E and 250C and 250F. As a result, the regularity of the slot arrangement is maintained, so that the microwaves can be uniformly supplied into the processing container 1 and uniform plasma can be generated.

  By supplying power into the processing container 1 using a plurality of microwave supply devices 250A to 250F as in the present embodiment, a plurality of low output power supplies equivalent to the case of using one high output oscillator are provided. It can be realized using an oscillator. Therefore, even when a large amount of power must be supplied to the processing container 1 such as when performing plasma processing using the processing container 1 having a large diameter, by using a plurality of microwave oscillators 42 with low output and low price, The manufacturing cost of the entire processing apparatus can be reduced.

  On the other hand, when the area of the dielectric plate 8 is increased in accordance with the increase in size of the antenna, it is necessary to reinforce the dielectric plate 8 so that the dielectric plate 8 can withstand high vacuum in the processing chamber 1. . In order to reinforce the dielectric plate 8, there is a method of passing the beam as a reinforcing member to the lower side of the dielectric plate 8 (inside the processing container 1) and supporting the dielectric plate 8 from the lower side. In the present embodiment, microwaves are not radiated from the vicinity of the side walls 16 to 18 that form the boundary between a plurality of adjacent antenna arrays 210. For this reason, as shown in FIG.6 (b), the influence of the beam 81 with respect to a microwave can be made small by extending the beam 81 so that this boundary may be opposed.

FIG. 7 is a diagram illustrating another configuration example when a plurality of microwave supply apparatuses are used in combination. In this figure, constituent elements corresponding to the constituent elements shown in FIG. 2 or 4 are denoted by the same reference numerals as those in FIG. 2 or FIG.
In this configuration example, as in the third embodiment, the slot 11 is not disposed in the central portion 460 of the surface of the waveguide slot antenna array 410 where the radiation slot 11 is formed, and the central portion 460 is excluded. The radiation slot 11 is arranged only in the region. Here, the portion 460 where the radiation slot 11 is not disposed is opposed to the central portion of the mounting table 2.

More specifically, the waveguide slot antenna array 410 of the microwave supply devices 450A, 450C, 450D, and 450F is provided with the radiation slot 11 over the entire area, whereas the microwave supply devices 450B and 450E are guided. In the waveguide slot antenna array 410, the radiating slot 11 is disposed only in the region excluding the tip region (that is, the radiating slot 11 is not disposed in the region of the other end of the radiating waveguide that is short-circuited). .
By arranging the radiation slot 11 in this way, the plasma generation in the upper space of the central portion of the mounting table 2 having a high plasma density can be suppressed and the plasma density distribution can be made uniform as in the third embodiment. Can be

(Fifth embodiment)
FIG. 8 is a perspective view showing a main configuration of a microwave supply device used in a plasma processing apparatus according to the fifth embodiment of the present invention. 9 is a longitudinal sectional view in the direction of the line IX-IX ′ in FIG. 10 is a cross-sectional view in the direction of the line XX ′ in FIG.
The microwave supply device 550 shown in FIGS. 8 to 10 includes a microwave oscillator (not shown), a microwave waveguide 541 composed of a rectangular waveguide that guides the microwave generated by the microwave oscillator, and a microwave waveguide 541. And an antenna member 570 for supplying the microwave guided by the above into the processing container 1.

Here, the antenna member 570 includes a box 571 having a rectangular parallelepiped shape with a low height. The box 571 includes two flat plates 513 and 514 (see FIG. 9) that are arranged in parallel and spaced apart from each other, and side walls 515, 516, and 517 that connect the peripheral portions of the flat plates 513 and 514, respectively. 518 (see FIG. 10). The flat plates 513 and 514 and the side walls 515 to 518 are formed of a conductor such as copper.
As shown in FIG. 11, the inside of the box 571 is divided into three blocks (A, B, C) in the Y direction parallel to the side walls 516, 518, and each block (A, B, C) is It is divided into four radiation blocks (A1, A2, A3, A4, B1, B2, B3, B4, C1, C2, C3, C4) in the X direction parallel to the side walls 515, 517. Therefore, the inside of the box 571 is divided into a total of 12 radiation blocks.

  Each radiation block of the box body 571 is partitioned by partition members 523 and 524 formed of a conductor such as copper. However, the boundaries of the radiation blocks B1 to B4 are completely opened, and the boundaries of the radiation blocks Ai, Bi, and Ci are partially opened (i = 1, 2, 3, 4). As a result, as shown in FIG. 10, the partition member 523 is composed of two flat plates connected in a T shape, and the partition member 524 is composed of one flat plate. The partition members 523 and 524 extend between the flat plates 513 and 514 constituting the box of the antenna member 570, and are connected to both of them.

  As shown in FIG. 11, each radiation block of the box 571 has a square shape with a side length of approximately λg / 2. Further, as shown in FIG. 9, the height of the box 571 is approximately λg / 4. Here, λg is the in-tube wavelength of the box 571. Therefore, the radiation blocks B1 to B4 communicating with each other act as a rectangular waveguide extending in the X direction, and the radiation blocks A1 to C1, A2 to C2, A3 to C3, and A4 to C4 are respectively Y direction. Acts as a rectangular waveguide extending to

  A rectangular opening 542 is formed in the flat plate 513 which is the upper surface of the box body 571, and a microwave waveguide 541 connected to a microwave oscillator is connected around the opening 542. More specifically, an intermediate position between the two H surfaces (wider wall surfaces) of the microwave waveguide 541 made of a rectangular waveguide is located on the boundary line between the radiation block B2 and the radiation block B3. In addition, an opening 542 is formed. Here, the flat plate 513 to which the microwave waveguide 541 is connected is an H surface of a rectangular waveguide composed of the radiation blocks B1 to B4. Therefore, the lines of magnetic force in the tube of the microwave waveguide 541 and in the radiation blocks B2 and B3 of the box 571 are as indicated by the arrow lines in FIGS. 12A and 12B, respectively, and are guided by the microwave waveguide 541. The microwaves thus distributed can be distributed and supplied so that the phases of the radiation block B2 and the radiation block B3 are reversed.

  The microwaves supplied to the radiation blocks B2 and B3 propagate to the radiation blocks B1 and B4, respectively. Further, the microwaves of the radiation blocks B1 to B4 are distributed to the radiation blocks A1 to A4 and the radiation blocks C1 to C4 through the opening 512. Since the length of one side of each radiation block is approximately λg / 2, the lines of magnetic force in each radiation block are as shown in FIG.

  As shown in FIG. 10, a radiation slot 511 is formed on the flat plate 514 that is the lower surface of the box 571. In this example, each of the radiation blocks of the box 571 is formed with a C-shaped slot including two slots 511A and 511B. The slot 511A having a short length is disposed at a position where the magnetic field lines are directed leftward, the slot 511B having a long length is disposed at a position where the magnetic field lines are directed downward, and the two slots 511A and 511B are orthogonal to each other on the extension line. To do. Therefore, by setting the phase of the radiation electric field to + 45 ° in the slot 511A and −45 ° in the slot 511B, the microwaves radiated from the slots 511A and 511B become circularly polarized waves.

  Note that the radiated power in each of the slots 511A and 511B is approximately ½ that in the case of emitting linearly polarized waves. As a result, the circularly polarized power is equivalent to that in the case of radiating linearly polarized waves, but the radiation power in each of the slots 511A and 511B is reduced, so that the risk of discharge occurring in each slot 511A and 511B is reduced.

  In the antenna member 570 having such a configuration, the rectangular waveguide and the opening 512 formed of the radiation blocks B1 to B4 of the box 571 have the radiation block similar to the microwave distributor 30 in the first embodiment. It has the function of distributing and supplying microwaves to A1 to A4 and C1 to C4. Further, the radiation blocks A1 to A4 and the radiation blocks C1 to C4 receive the microwaves introduced from the microwave distributor 30 in the radiation slots, like the waveguide slot antenna array 10 in the first embodiment. It has the effect | action supplied to the inside of the processing container 1 via 511. Therefore, the antenna member 570 is provided with the waveguide slot antenna array 10 on both sides of the microwave distributor 30 in the first embodiment, and further, the lower surface of the feeding waveguide of the microwave distributor 30 (that is, It can be understood that the radiation slot 511 is formed on the wall (facing the mounting table 2).

Therefore, in this embodiment, it is possible to obtain the same effect as that of the first embodiment. That is, it is possible to suppress the complexity and increase in size of the device configuration when the number of waveguide slot antennas is increased to increase the opening area, and it is possible to increase the degree of design freedom of the device configuration. In addition, it is not necessary to increase the cross-sectional size of the radiating waveguide of the waveguide slot antenna, and the area can be increased by increasing the number of radiating blocks. Wave control becomes easier. Further, since it is not necessary to excite surface waves in the dielectric plate 8, it is possible to realize a low electron temperature plasma with uniform plasma distribution and less substrate damage and metal contamination in the processing chamber 1.
In addition, in this embodiment, a member having the function of only the microwave distributor 30 is not required, so that the apparatus configuration can be further simplified and miniaturized as compared with the first embodiment.

Next, a modified example of the antenna member 570 will be described.
First, the partition member will be described.
FIG. 13 is a diagram illustrating a planar shape of a partition member that can be used for the antenna member 570. In this figure, the dotted line represents the boundary line of each radiation block of the box 571.

As the partition member, in addition to partition members 525A and 525B made of a single flat plate as shown in FIGS. 13A and 13B, a partition member having a T-shape in plan view as shown in FIG. 13C. 525C, a partition member 525D having a cross shape in plan view as shown in FIG. 13 (d), and a partition member 525E having an L shape in plan view as shown in FIG. 13 (e) can be used. The partition members 523 and 524 in FIG. 10 are the same type as the partition members 525C and 525A shown in FIGS. 13C and 13A, respectively.
Moreover, in FIG. 11, since each boundary of radiation | emission block A1-A4, C1-C4 may open, the columnar partition member 525F as shown in FIG.13 (f) can also be used.

Next, another example of the radiation slot 511 will be described.
FIG. 14 is a view showing another arrangement example of the radiation slot 511. The radiation slot 511 shown in this figure is also a C-shaped slot composed of two slots 511C and 511D. However, the slots 511C and 511D form an angle of about 45 ° with respect to the axis of the rectangular waveguide formed of the radiation blocks Ai, Bi, and Ci (i = 1, 2, 3, 4).

FIG. 15 is a diagram showing a design example of the radiation slot 511 shown in FIG. FIG. 16 is a diagram showing the microwave radiation characteristics of the radiation slot. The horizontal axis represents the slot length divided by the free space wavelength of microwaves (122 mm for microwaves having a frequency of 2.45 GHz) λ ₀ , and the vertical axis represents the relative gain [dB] or phase [ deg].
In the example shown in FIG. 15, the angle formed by the two slots 511C and 511D is 90 °, and the lengths thereof are 0.43λ ₀ and 0.51λ ₀ . Assuming that the lengths of the slots 511C and 511D are 0.43λ ₀ and 0.51λ ₀ , the phase of the radiation electric field is + 45 ° and −45 ° as can be seen from FIG. Therefore, the microwaves radiated from the slots 511C and 511D can be circularly polarized.

FIG. 17 is a diagram showing still another arrangement example of the slots for radiation. The radiation slot 511E shown in this figure is arranged at a position where the magnetic lines of force are directed downward in each radiation block, and the radiated microwave is linearly polarized.
Note that the polarization may be changed depending on the position of the radiation slot 511 in the antenna member 570. For example, by making the microwave radiated near the side wall of the processing container 1 into a linearly polarized wave parallel to the side wall, leakage of the microwave can be reduced. Further, the polarization may be set according to the state of the plasma generated inside the processing container 1. For example, when it is desired to increase the electron temperature, it is advisable to make it linearly polarized.

Next, variations in the arrangement of the radiation blocks will be described.
In the present embodiment, the inside of the box 571 is divided into a plurality of radiation blocks, and each radiation block is partitioned by a partition member as necessary. Therefore, the number and arrangement of the radiation blocks can be freely changed depending on the size and shape of the box body 571.
For example, as shown in FIG. 18, for a box 571C having a length in the X direction of λg and a length in the Y direction of 3 × λg / 2, the inside of the box 571C has 2 × 3 = 6 radiation blocks. Can be divided into

Further, for the box body 571D having a length of 3 × λg / 2 in both the X direction and the Y direction as shown in FIG. 19, the interior of the box body 571D may be set to 2 × 3 = You may divide into six radiation blocks. At this time, if the lengths of the sides of one radiation block in the X direction and the Y direction are ax and ay,
λg = λ ₀ / {1- (λ ₀ / 2ax) ² } ^1/2
λg / 2 = ay
The relational expression is preferably set so as to satisfy.

Further, the length in the Y direction of the portion (the radiation blocks A1 to A4 and C1 to C4 in FIG. 11) acting as the waveguide slot antenna array 10 in the first embodiment is extended, and a plurality of radiations in the Y direction are performed. A block may be arranged. FIG. 20 shows an example in which the length in the Y direction of the portions AA and CC acting as the waveguide slot antenna array 10 is λg, and two radiation blocks are arranged in the Y direction.
Further, as shown in FIG. 21, the portion AA that acts as the waveguide slot antenna array 10 may be provided only on one side of the portion B that acts as the microwave distributor 30.

  As described above, since the number and arrangement of the radiation blocks have a large degree of freedom, the box 571 is selected in accordance with the diameter and shape of the opening of the processing container 1 and the inside of the processing container 1 is made into a block. A radiation block can be arranged over the entire opening. Therefore, according to the present embodiment, it is possible to cover the opening of the processing container 1 with the antenna more easily than configuring the antenna by combining a plurality of radiation waveguides.

(Sixth embodiment)
A plasma processing apparatus according to the sixth embodiment of the present invention uses a combination of a plurality of microwave supply apparatuses 550 in the fifth embodiment.
FIG. 22 is a plan view showing a configuration example when a plurality of microwave supply devices 550 are used in combination. FIG. 23 is a diagram illustrating the dimensions of the antenna member 570 of the microwave supply device 550. 24 is a cross-sectional view taken along line XXIV-XXIV ′ in FIG. In this figure, constituent elements corresponding to the constituent elements shown in FIG. 1 are denoted by the same reference numerals as in FIG.

As shown in FIG. 22, when the dimension of the LCD substrate 3 is 1100 mm × 1300 mm, for example, the processing container 1 having a diameter of 1500 mm × 1500 mm is used. In addition, 3 × 3 = 9 antenna members 570 each having a box body 571 of 346.4 mm × 346.4 mm are arranged in the upper part of the opening of the processing container 1. As shown in FIG. 23, the inside of the box 571 is divided into 16 radiation blocks of 86.6 mm × 86.6 mm.
Thus, by using a plurality of microwave supply devices 550, the same operational effects as those of the fourth embodiment described above can be obtained. That is, a low-price and low-price microwave oscillator can be used for each microwave supply device 550, and as a result, the manufacturing cost of the entire plasma processing apparatus can be reduced.

Also in the present embodiment, similarly to the fourth embodiment, the upper opening of the processing container 1 is closed with one dielectric plate 8 and a plurality of antenna members 570 are arranged on the dielectric plate 8. However, as shown in FIG. 24, only the lower part of each antenna member 570 may be formed of a dielectric plate 8A. In this case, since it is not necessary to increase the area of the dielectric plate, the strength of the dielectric plate can be maintained. The dielectric plate 8 </ b> A disposed only in the lower part of the antenna member 570 is supported by the beam 1 </ b> A that is passed through the upper opening of the processing container 1. A sealing member 1B such as an O-ring is interposed between the dielectric plate 8A and the beam 1A, and between the base of the beam 1A and the upper surface of the side wall of the processing container 1, thereby ensuring airtightness in the processing container 1. To do.
Further, a gas introduction pipe 7A for introducing gas into the processing container 1 may be provided on the beam 1A. Furthermore, a metallic shower plate (not shown) may be disposed in the upper space of the mounting table 2 so that the gas introduced from the gas introduction pipe 7A is made uniform.

  Further, the lower surface of the antenna member 570 where the radiation slot 511 is formed may be brought into contact with the dielectric member 8A. In this case, the temperature of the dielectric plate 8A can be adjusted by controlling the temperature of the antenna member 570. By cooling the antenna member 570 and cooling the dielectric plate 8A, the temperature rise of the dielectric plate 8A due to the plasma heat flow can be suppressed, and damage to the dielectric plate 8A due to thermal expansion can be prevented. In addition, when performing a process using a deposition gas such as a fluorocarbon gas, the antenna member 570 is heated to bring the temperature of the dielectric plate 8A to about 150 ° C. The position can be prevented and the process can be stabilized.

(Seventh embodiment)
In the fifth embodiment, an example in which a rectangular waveguide is used as the microwave waveguide 541 of the microwave supply device 550 has been described. However, the present invention is not limited to this. For example, a coaxial waveguide is used. Also good. An example using this coaxial waveguide will be described as a seventh embodiment of the present invention.
FIG. 25 is a longitudinal cross-sectional view showing a main configuration of a microwave supply device used in the plasma processing apparatus according to the seventh embodiment of the present invention. 26 is a cross-sectional view in the direction of the line XXVI-XXVI ′ in FIG. In these drawings, components corresponding to those shown in FIGS. 8 to 10 are denoted by the same reference numerals as those in FIGS.
The microwave supply device 650 shown in FIGS. 25 and 26 includes a microwave oscillator (not shown), a microwave waveguide 641 including a coaxial waveguide that guides the microwave generated by the microwave oscillator, and a microwave waveguide 641. And an antenna member 670 for supplying the microwave guided by the above into the processing container 1.

  A circular opening 642 is formed in the flat plate 513 that is the upper surface of the box 671 of the antenna member 670. The opening 642 is formed in the central portion of the radiation block inside the box body 671, and the outer conductor 641 </ b> A of the microwave waveguide 641 is connected around the opening 642. The inner conductor 641B arranged coaxially with the outer conductor 641A extends through the opening 642 to the inside of the box 671. The tip of the internal conductor 641B may be connected to the flat plate 514 that is the lower surface of the box 671 as shown in FIG. 25A, or may not be connected as shown in FIG. Good. In the former case, a taper 643 is attached to the tip of the inner conductor 641B to moderate the impedance change from the microwave waveguide 641 to the antenna member 670, and at the connection portion between the microwave waveguide 641 and the antenna member 670. The reflection of microwaves can be reduced.

The magnetic lines of force in the tube of the microwave waveguide 641 rotate around the inner conductor 641B as indicated by the arrow in FIG. Therefore, by connecting the microwave waveguide 641 to the central portion of the radiation block as described above, the lines of magnetic force in the radiation block are as indicated by the arrow lines in FIG. 27B, and are shown in FIG. Thus, microwaves can be distributed to all blocks.
Similarly to the sixth embodiment, a plurality of microwave supply devices 650 using a coaxial waveguide may be used in combination as the microwave waveguide 641. An example of the configuration is shown in FIG. In this figure, 3 × 3 = 9 antenna members 670 of the microwave supply device 650 are arranged in a matrix shape above the opening of the processing container 1.

  Although various embodiments of the present invention have been described above, the present invention also includes combinations of technical ideas included in the above-described embodiments.

  The plasma processing apparatus of the present invention can be used for an etching apparatus, a CVD apparatus, an ashing apparatus, and the like. The plasma processing method of the present invention can be used for processing such as etching, ashing, and CVD. Furthermore, these plasma processing apparatuses and methods can also be used in the manufacture of flat panel display devices such as LCDs.

It is a longitudinal section showing the whole plasma treatment equipment composition concerning a 1st embodiment of the present invention. It is a cross-sectional view of the structure of the microwave supply apparatus used for the plasma processing apparatus shown in FIG. It is a transverse cross section showing an example of composition of a slot for radiation. It is a cross-sectional view which shows the structure of the microwave supply apparatus used for the plasma processing apparatus which concerns on the 2nd Embodiment of this invention. It is a cross-sectional view which shows the structure of the microwave supply apparatus used for the plasma processing apparatus which concerns on the 3rd Embodiment of this invention. It is a figure which shows one structural example in the case of using in combination the several microwave supply apparatus in the plasma processing apparatus which concerns on the 4th Embodiment of this invention. It is a figure which shows the other structural example in the case of using combining a several microwave supply apparatus. It is a perspective view which shows the principal part structure of the microwave supply apparatus used for the plasma processing apparatus which concerns on the 5th Embodiment of this invention. It is a longitudinal cross-sectional view of the IX-IX 'line direction in FIG. FIG. 10 is a transverse cross-sectional view in the direction of the line XX ′ in FIG. 9. It is a figure which shows the example of arrangement | positioning of the block for radiation | emission inside a box. It is a figure which shows the magnetic force line in the block for radiation | emission to which the inside of the pipe | tube of a microwave waveguide and the microwave waveguide were connected. It is a figure which shows the planar shape of the partition member which can be used for an antenna member. It is a figure which shows the other example of arrangement | positioning of the slot for radiation | emission. It is a figure which shows the example of a design of the slot for radiation | emission shown in FIG. It is a figure which shows the microwave radiation characteristic of the slot for radiation | emission. It is a figure which shows the further example of arrangement | positioning of the slot for radiation | emission. It is a figure which shows the other example of arrangement | positioning of the block for radiation | emission inside a box. It is a figure which shows the other example of arrangement | positioning of the block for radiation | emission inside a box. It is a figure which shows the other example of arrangement | positioning of the block for radiation | emission inside a box. It is a figure which shows the other example of arrangement | positioning of the block for radiation | emission inside a box. It is a top view which shows one structural example in the case of using combining multiple microwave supply apparatuses. It is a figure which shows the dimension of the antenna member of a microwave supply apparatus. It is sectional drawing of the XXIV-XXIV 'line direction in FIG. FIG. 25 is a longitudinal cross-sectional view showing a main configuration of a microwave supply device used in the plasma processing apparatus according to the seventh embodiment of the present invention. FIG. 26 is a transverse sectional view in the direction of line XXVI-XXVI ′ in FIG. 25. It is a figure which shows the magnetic force line in the block for radiation | emission to which the inside of the pipe | tube of a microwave waveguide and the microwave waveguide were connected. It is a top view which shows one structural example in the case of using combining multiple microwave supply apparatuses. It is a longitudinal cross-sectional view which shows the whole structure of the conventional plasma processing apparatus using a waveguide slot antenna array. It is a cross-sectional view of a part of the configuration including the waveguide slot antenna array.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Processing container, 1A ... Beam, 1B ... Sealing member, 2 ... Mounting base, 3 ... LCD substrate, 4 ... Matching box, 5 ... High frequency power supply, 6 ... Exhaust port, 7 ... Gas inlet port, 7A ... Gas inlet tube 8, 8A ... dielectric plate, 9 ... shield material, 10, 110, 210, 310, 410 ... waveguide slot antenna array, 10A-10H, 110A-110H, 210A-210H, 310A-310H ... waveguide Slot antenna, 11, 111, 511... Slot for radiation, 12, 212... Slot for feeding, 13, 14, 513, 514... Flat plate, 15-18, 515-518, 517A, 517B ... side wall, 19, 20, 219 220 ... partition plate, 21 ... slow wave material, 21A ... gradient, 22 ... microwave absorber, 30, 230 ... microwave distributor, 31 ... opening, 32, 232 ... invitation Wall, 41, 541, 641 ... microwave waveguide, 42 ... microwave oscillator, 43 ... iris (impedance matching device), 50, 150, 250, 250A-250F, 350, 450A-450F, 550, 650 ... microwave Supply device, 81: Beam (reinforcing member), 511A to 511E ... Slot, 512 ... Opening, 523, 524, 525A to 525F ... Partition member, 542, 642 ... Opening, 570, 670 ... Antenna member, 571, 571A to 571F , 671 ... box, 641A ... external conductor, 641B ... internal conductor, 643 ... taper, A1 to A4, B1 to B4, C1 to C4 ... radiation block.

Claims (25)

A mounting table for mounting the object to be processed, a processing container for storing the mounting table, and a plurality of waveguide slot antennas having slots formed in the radiating waveguide are arranged in the axial direction of the radiating waveguide. In a plasma processing apparatus, comprising: an antenna array arranged in an orthogonal width direction and opposed to the mounting table; and a distributor connected to one end of the radiation waveguide and distributing a microwave to each of the antenna waveguides. ,
The distributor is
A feeding waveguide extending in the width direction of the waveguide slot antenna;
A plasma processing apparatus comprising: the radiation waveguide formed on a wall surface of the power supply waveguide; and an opening that communicates the power supply waveguide. The plasma processing apparatus according to claim 1,
A plasma processing apparatus, wherein a slot is formed on a wall surface of the power supply waveguide facing the mounting table. In the plasma processing apparatus according to claim 1 or 2,
The distributor includes an induction wall that projects from the wall surface of the power supply waveguide facing the opening toward the opening and guides the microwave propagating through the power supply waveguide to the radiation waveguide. A plasma processing apparatus further comprising: In the plasma processing apparatus according to claim 1 or 2,
The plasma processing apparatus, wherein the antenna arrays are provided on both sides of the feeding waveguide. In the plasma processing apparatus described in any one of Claims 1-4,
A plasma processing apparatus comprising a slow wave material made of a dielectric material disposed only in a tube of the radiation waveguide. The plasma processing apparatus according to claim 5, wherein
The plasma processing apparatus, wherein the slow wave material has a gradient at an end portion on the one end side of the radiation waveguide. In the plasma processing apparatus described in any one of Claims 1-6,
The width of the radiating waveguide is approximately ½ of the in-tube wavelength of the feeding waveguide,
The plasma processing apparatus is characterized in that the openings are arranged at substantially the same interval as the in-tube wavelength of the power supply waveguide, and two adjacent radiation waveguides are communicated with the power supply waveguide. . In the plasma processing apparatus described in any one of Claims 1-7,
Two conductor plates arranged substantially parallel to each other;
A partition member extending between the two conductor plates and made of a conductor that partitions a space formed by the two conductor plates;
The plasma processing apparatus, wherein the radiation waveguide and the power feeding waveguide are formed from the two conductor plates and the partition member. In the plasma processing apparatus described in any one of Claims 1-8,
A microwave oscillator that generates microwaves;
A microwave waveguide for guiding the microwave output from the microwave oscillator to the feeding waveguide;
A plasma processing apparatus comprising: an impedance matching unit provided in the microwave waveguide for matching impedances of a power supply side and a load side. The plasma processing apparatus according to claim 9, wherein
The said impedance matching device is provided in the connection part of the said waveguide for electric power feeding and the said microwave waveguide, and consists of an iris which narrows the pipe line of the said microwave waveguide, The plasma processing apparatus characterized by the above-mentioned. In the plasma processing apparatus described in any one of Claims 1-8,
A plasma processing apparatus comprising a plurality of microwave supply devices including the antenna array, the distributor, and a microwave oscillator for supplying the microwave to the distributor. The plasma processing apparatus according to claim 11, wherein
The two microwave supply devices are arranged so that the other ends of the radiation waveguides of the two microwave supply devices face each other, and the slots formed in the radiation waveguides of the two microwave supply devices are aligned on the same straight line. A plasma processing apparatus. The plasma processing apparatus according to claim 11 or 12,
The plurality of antenna arrays are arranged outside the processing container,
A dielectric plate closing the antenna array side end of the processing container;
A plasma processing apparatus, comprising: a reinforcing member that extends so as to face boundaries between a plurality of adjacent antenna arrays and supports the dielectric plate. In the plasma processing apparatus described in any one of Claims 1-13,
The plasma processing apparatus, wherein the number of the slots formed in the radiation waveguide differs depending on a position where the radiation waveguide is arranged in the antenna array. The plasma processing apparatus according to claim 14, wherein
2. The plasma processing apparatus according to claim 1, wherein the slot is formed only in a region excluding a central portion of a surface facing the mounting table formed by combining all the radiation waveguides. In the plasma processing apparatus according to claim 14 or 15,
The plasma processing apparatus is characterized in that the distributor supplies smaller power to a radiation waveguide having a smaller number of slots. The plasma processing apparatus according to claim 1,
The plasma processing apparatus, wherein the waveguide slot antenna supplies circularly polarized waves from the slot into the processing container. The plasma processing apparatus according to claim 2, wherein
The plasma processing apparatus, wherein the waveguide slot antenna and the distributor supply circularly polarized waves from the slot to the inside of the processing container. A plurality of waveguide slot antennas each having a slot formed in a radiating waveguide are arranged in a width direction perpendicular to the axial direction of the radiating waveguide, and a microwave is introduced into a processing container. In the plasma processing method of supplying and processing the object to be processed on the mounting table accommodated in the processing container using the plasma generated by the microwave supplied in the processing container,
Supplying a microwave to a power supply waveguide constituting a distributor, supplying the microwave to each of the radiation waveguides through a plurality of openings formed in a side wall of the power supply waveguide, A plasma processing method, wherein the microwave is supplied into the processing container through the slot formed in the radiation waveguide. The plasma processing method according to claim 19, wherein
A plasma processing method, wherein a slow wave material made of a dielectric is disposed only in a tube of the radiation waveguide, and a plurality of slots formed in the radiation waveguide are shortened. The plasma processing method according to claim 19 or 20,
Two conductor plates are arranged substantially parallel to each other, and a space formed by the two conductor plates is partitioned by a partition member made of a conductor extending between the two conductor plates, and the two conductor plates and The plasma processing method, wherein the radiation waveguide and the power supply waveguide are formed from the partition member. In the plasma processing method as described in any one of Claims 19-21,
A plasma processing method using a plurality of microwave supply apparatuses including the antenna array, the distributor, and a microwave oscillator for supplying the microwave to the distributor. In the plasma processing method as described in any one of Claims 19-22,
A plasma processing method, wherein the slot is formed only in a region excluding a central portion of a surface facing the mounting table formed by combining all the radiation waveguides. In the plasma processing method as described in any one of Claims 19-23,
The antenna array is disposed outside the processing container, the antenna array side end of the processing container is closed with a dielectric plate, and the temperature of the antenna array is in a state where the antenna array is in contact with the dielectric plate. The plasma processing method characterized by controlling. 25. A flat panel display device, wherein the object to be processed is subjected to at least one of etching, ashing, and CVD by using the plasma processing method according to any one of claims 19 to 24. Production method.

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