JPH06232114A - Plasma processing device - Google Patents

Abstract

(57) [Summary] [Purpose] To enable uniform treatment with ions or neutral active species in a plasma treatment apparatus that transmits and uses microwaves through a transmission path. [Structure] Two ends of a rectangular waveguide 12 are arranged by branching the end of a transmission line 1 for transmitting microwaves, and an insulating gas pipe 21 is arranged so as to penetrate each of the rectangular waveguides 12. To do. The gas introduction system 2 is installed in the gas pipe 21.
A plasma-forming gas is introduced by the plasma-forming gas, and plasma is formed by microwave coupling. The extension part 211 extending to the downstream side of each gas pipe 21 constitutes a guide means, and carries ions and neutral active species generated by plasma to the processing container 5 below. Each extension part 211 is provided at an equal position with respect to the surface of the substrate 30 to be processed,
The ions and neutral active species uniformly diffuse inside the processing container 5 and reach the substrate 30.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a plasma processing apparatus for performing processing such as ashing, etching, CVD (chemical vapor deposition) and the like by using ions and neutral active species generated by plasma.

[0002]

2. Description of the Related Art In the field of wafer processing and the like in the LSI manufacturing process, various processes using plasma have been actively studied and put into practical use. For example, there are plasma etching in which etching is performed by reaction with neutral active species generated by plasma, plasma CVD in which the reaction is promoted by plasma, and the like.

A conventional configuration of such a plasma processing apparatus will be described with reference to FIG. FIG. 5 is a schematic explanatory view of an example of a conventional plasma processing apparatus. The conventional plasma processing apparatus shown in FIG. 5 includes a processing container 5, a substrate holder 3 installed at the bottom of the processing container 5, and a hemispherical chamber arranged so as to cover the substrate holder 3 from above. 6 and
It mainly comprises a transmission line 1 for transmitting a microwave generated by a microwave oscillator (not shown) arranged outside the apparatus to the processing container 5.

The transmission line 1 is a rectangular waveguide 11 for main transmission, which is connected to a microwave oscillator, and a tapered cylindrical waveguide, which is connected to a portion of a microwave introduction port 50 provided in the upper part of the processing container 5. 15 and a circle-to-rectangle converter 16 that connects the rectangular waveguide 11 and the tapered cylindrical waveguide 15 to each other. The chamber 6 is for introducing a plasma forming gas into the chamber 6 to form a predetermined plasma in a space facing the substrate 30. Therefore, the chamber 6 is provided with a plasma forming gas introduction portion (not shown). Also,
The chamber 6 is made of a chemically stable high-melting point insulating material capable of transmitting microwaves, that is, a material such as quartz glass. The substrate holder 3 is for mounting the substrate 30 on the substrate 30 for processing, and in many cases, a heater 31 is provided inside to heat the substrate 30.

In the conventional plasma processing apparatus having the above structure, the substrate 30 is placed on the substrate holder 3 in advance and a predetermined plasma forming gas is introduced into the chamber 6. Then, the microwave generated by a microwave oscillator (not shown) is transmitted through the transmission line 1 and introduced into the processing container 5 through the microwave introduction port 50. The microwave penetrates the chamber 6 and reaches the inside of the chamber 6, and is coupled to the plasma forming gas to turn the gas into a plasma state. Then, the predetermined processing is performed on the substrate 30 by the action of the ions in the plasma, the neutral neutral active species, and the like. That is, for example, the etching is performed by the reaction between the neutral active species gas and the material of the substrate.

As is clear from the above description and FIG.
In the conventional plasma processing apparatus, the substrate 30 is arranged in the vicinity of the plasma formation region, that is, the coupling portion between the microwave and the plasma formation gas, and the generated plasma is used on the spot. Here, as is well known, various transmission modes exist in the microwave transmitted through the transmission path, and the microwave introduced into the chamber 6 in FIG. 5 has an electromagnetic field distribution according to a certain transmission mode. ing. Incidentally, such a microwave distribution can be indirectly confirmed by observing the shape of plasma emission.

[0007]

The existence of the microwave transmission mode causes a problem of non-uniformity of processing in the processing apparatus using plasma by the microwave as in the present invention. That is, the introduced microwave has an intensity distribution according to the transmission mode and is non-uniform, so that the density distribution or the ionization degree distribution of the formed plasma is also non-uniform. Therefore, the distribution of ions and neutral active species generated by plasma becomes non-uniform, and the treatment of the substrate with these materials becomes non-uniform. For example, in the case of plasma etching, the etching rate becomes uneven at each point on the substrate. The invention of the present application has been made in view of the above problems, and makes it possible to perform uniform treatment with ions or neutral active species in a plasma processing apparatus that transmits and uses microwaves through a transmission path. Is intended.

[0008]

In order to achieve the above object, a plasma processing apparatus according to claim 1 of the present application comprises a microwave oscillator, a transmission line for transmitting the microwave oscillated by the microwave oscillator, A gas introduction system for guiding a plasma forming gas, and a substrate holder for holding the substrate,
The transmission line is formed so that a plurality of plasma forming regions, which are regions where plasma is formed by combining microwaves with the plasma forming gas, are formed at positions facing the substrate.
Microwaves are guided to each of a plurality of plasma forming regions facing the substrate, the gas introduction system is for guiding a plasma forming gas to each of these plasma forming regions, and further, each plasma forming region is formed. A plurality of guide means for guiding the ions or neutral active species generated in the region to the substrate held by the substrate holder are provided at even positions with respect to the surface of the substrate to be processed. Similarly, in order to achieve the above object, in the plasma processing apparatus according to claim 2, in the configuration according to claim 1, the transmission line is connected to the microwave oscillator, and the end is short-circuited by the terminal short-circuit plate. The gas introduction system is configured to introduce a plasma-forming gas into a plurality of gas pipes, and each gas pipe has a position of an antinode of a standing wave in the waveguide. The gas pipe of the penetrating portion forms a plasma formation region, and at least the penetrating gas pipe has an insulating property. Similarly, in order to achieve the above-mentioned object, claim 3
In the plasma processing apparatus according to the second aspect of the present invention, in the configuration according to the second aspect, the rectangular waveguide forming the transmission line has a terminal end,
A branched rectangular waveguide is connected and branched into a plurality, and a gas pipe is arranged so as to penetrate through each branched waveguide. Similarly, in order to achieve the above object, in the plasma processing apparatus according to claim 4, in the configuration according to claim 2 or 3, the plurality of gas pipes are formed from a portion penetrating the waveguide or the cavity resonator. The extension part extended to the downstream side is formed toward the surface of the substrate to form the guide means, and the extension parts of the gas pipes are arranged uniformly with respect to the surface of the substrate. Similarly, in order to achieve the above object, in the plasma processing apparatus according to claim 5, in the configuration according to claim 1, 2, 3 or 4, the transmission line has a branching part for branching the microwave. However, the microwave oscillated from one microwave oscillator is branched and transmitted to a plurality of plasma formation regions. Similarly, in order to achieve the above object, in the plasma processing apparatus according to claim 6, in the configuration according to claim 1, 2, 3 or 4, the microwave oscillator corresponds to the number of plasma formation regions. A plurality of transmission lines are arranged, and the transmission line has a configuration for transmitting microwaves to each plasma formation region corresponding to each microwave oscillator. Similarly, in order to achieve the above-mentioned object, the plasma processing apparatus according to claim 7 has
The configuration described in any one of 2, 3, 4, 5 and 6 has a configuration in which a matching unit is arranged on the transmission line on the input side of the plasma formation region. Similarly, in order to achieve the above-mentioned object, the plasma processing apparatus according to claim 8 has
In the structure described in 2, 3, 4, 5, 6 or 7, an isolator is arranged on the transmission line.

[0009]

In the plasma processing apparatus described in each of the above claims, the microwave is coupled to the plasma forming gas introduced into each of the plurality of plasma forming regions to form plasma at a plurality of positions. Then, the ions or neutral active species generated by each plasma are evenly guided to the surface of the substrate by the guide means and reach the substrate, and as a result, the substrate is processed.

[0010]

EXAMPLES Next, examples of the present invention will be described. In both of the following two examples, plasma is formed at a plurality of positions facing the substrate, and the ions or neutral active species generated by each plasma are evenly guided to the surface of the substrate. is there. Plasma is formed in two regions in the first embodiment, and plasma is formed in four regions in the second embodiment.

FIG. 1 is a schematic perspective view showing a first embodiment of the present invention, and FIG. 2 is an explanatory view of a penetrating portion of a gas pipe in the embodiment of FIG. The plasma processing apparatus shown in FIG. 1 holds a microwave oscillator (not shown), a transmission line 1 for transmitting the microwave oscillated by the microwave oscillator, a gas introduction system 2 for guiding a plasma forming gas, and a substrate 30. Substrate holder 3 for

The transmission line 1 is composed of rectangular waveguides 11 and 12, and the gas introduction system 2 is arranged inside a plurality of gas pipes 21 penetrating the rectangular waveguide 12 to form a plasma forming gas. Is to be introduced. Therefore, the inside of the plurality of gas pipes 21 is the plasma formation region 7, and these positions are positions facing the substrate 30. further,
An extension portion 211, which extends toward the downstream side from the portion penetrating the rectangular waveguides 11 and 12, is formed toward the surface of the substrate 30 to form a guide unit.

First, as a microwave oscillator (not shown), a known one using a magnetron or the like is adopted.
For example, a microwave of 2.45 GHz is oscillated. As described above, the rectangular waveguides 11 and 12 are used as the transmission line 1. FIG. 1 shows the configuration of the terminal end of the transmission line 1. As can be seen from FIG. 1, the rectangular waveguide 11
Has two rectangular waveguides (hereinafter,
A branched rectangular waveguide) 12 is branched. Then, the two branched rectangular waveguides 12 are partitioned by a partition wall 121 and are adjacent to each other.
It is short-circuited at 22. The branch portion 13 is provided at a position on the input side (the side near the microwave oscillator in the transmission path) from the terminal short-circuit plate 122 by a predetermined distance. Specifically, the branch portion 13 is an opening provided in the partition wall 121. The microwave transmitted by the transmission line 1
The branch portion 13 is branched into two branched rectangular waveguides 12 and is sent to the terminal short-circuiting plate 122 of each branched rectangular waveguide 12.

The gas introduction system 2 includes, in addition to the above-described gas pipe 21, a gas cylinder (not shown) containing a plasma forming gas, a blender (not shown), a flow controller (not shown) for controlling the gas flow rate, and the like. A plasma forming gas having a predetermined composition is introduced up to the gas pipe 21. Of course, the introduced plasma forming gas may contain other components necessary for processing such as etching and CVD, in addition to the components that form plasma by the coupling of microwaves. As can be seen from FIG. 1, two gas pipes 21 are arranged and penetrate each branch rectangular waveguide 12 in the vertical direction.
The gas pipe 21 is made of a chemically stable high melting point insulating material capable of transmitting microwaves, that is, a material such as quartz glass. The microwaves pass through the wall surface of the gas pipe 21 and combine with the internal plasma-forming gas to bring the plasma-forming gas into a plasma state, that is, to cause plasma discharge. Further, the penetrating position of the gas pipe 21 in the present embodiment is the branch rectangular waveguide 12
It is the belly part of the standing wave inside. More specifically, for example, the position is on the input side by a distance of about one quarter of the guide wavelength from the position of the terminal shorting plate 122 of the branched rectangular waveguide 12.
This is, needless to say, because plasma is efficiently generated by utilizing a portion having a large microwave amplitude.

Further, it is preferable that the gas pipe 21 is covered with a shield for the purpose of preventing leakage of microwave power from a portion penetrating the gas pipe 21.
Specifically, a cylindrical punch panel 4 as shown in FIG.
Is attached so as to cover the gas pipe 21. That is, the metal punch panel 4 is arranged so as to surround the gas pipes 21 above and below the portion exposed from the branched rectangular waveguide 12, and the end portion is fixed to the rectangular waveguide 12.
In order to completely shield the microwave, it is more desirable to arrange the punch panel 4 over the entire length of the gas pipe 21. In addition, the reason why the punch panel 4 is used instead of the flat plate is that the plasma formed inside can be visually recognized.

A processing container 5 is arranged below the branched rectangular waveguide 12. The extension part 211 of the gas pipe 21 as a guide means is arranged so as to connect the rectangular waveguide 12 and the processing container 5, and carries the generated ions and neutral active species to the processing container 5. do. Using the extension 211 of the gas pipe 21 as it is as a guide means in this way has the advantage that the structure of the device can be simplified. As a guide means,
In addition to the case where the extended portion of the gas pipe 21 is formed as in the present embodiment, there may be a case where another member is connected to the gas pipe. In any case, the guide means must be formed of a material that does not react with the guiding ion or the neutral neutral active species or lose the activity of the neutral active species. .

The processing container 5 has the substrate holder 3 housed therein, and the ions and neutral active species that have entered the processing container 5 reach the substrate 30 held by the substrate holder 3. A heater 31 is attached to the substrate holder 3 as in the conventional case, and the substrate 30 can be heated to, for example, about 150 ° C. to 250 ° C. Instead of the heating by the heater 31, radiant heating by a lamp can be adopted. The substrate holder 3 in the present embodiment only mounts the substrate 30 on the upper surface thereof, but the substrate holder 3 has a configuration in which the peripheral edge of the substrate 30 is gripped, a configuration in which the substrate 30 is adsorbed and held on the wall surface, and the like. Various other configurations may be employed. In addition, an exhaust system (not shown) is attached to the processing container 5,
For example, the inside can be exhausted to about 0.5 to 1.0 Torr.

Here, the connecting positions of the extension portions 211 of the two gas pipes 21 forming the guide means to the processing container 5 are equal to the surface of the substrate 30 inside the processing container 5. . To be precise, the respective extension parts 211 are connected at symmetrical positions with respect to the central axis of the substrate 30. Therefore, the ions and neutral active species guided by the respective extension portions 211 are uniformly diffused inside the processing container 5 and reach the substrate 30. still,
The central axis means a direction of a perpendicular line which stands from the center of the surface of the substrate 30. Also, as shown in FIG.
Are refracted in the middle, but this is mainly for preventing charged particles generated by the plasma from directly hitting the substrate 30 below. In addition, the apparatus of FIG.
A transfer system (not shown) for transferring 0 to the processing container 5 is provided, and the processing container 5 has a gate (not shown) for loading and unloading the substrate 30.

Next, the operation of the first embodiment having the above structure will be described. A transfer system (not shown) transfers the substrate 30,
The substrate 30 is loaded into the processing container 5 through a gate (not shown) and placed on the substrate holder 3. After closing the gate
An evacuation system (not shown) operates to evacuate to a predetermined degree of vacuum, and then the process is started. That is, the microwave oscillator (not shown) operates and the introduction of the plasma forming gas by the gas introduction system 2 is started. The oscillated microwave is transmitted through the transmission line 1 formed of the rectangular waveguide 11, branched at the branch portion 13 which is an opening, and sent to the end of the branched rectangular waveguide 12.

On the other hand, the gas introduction system 2 sends out a plasma forming gas from a gas cylinder (not shown), mixes it by a blender (not shown) as needed, and controls the flow rate by a flow rate controller (not shown). A plasma forming gas is introduced into the gas pipe 21. Then, the microwaves transmitted as described above pass through the wall surface of the gas pipe 21 and are coupled to the plasma forming gas inside the gas pipe 21 to turn the plasma forming gas into a plasma state.

As a result, desired materials such as ions and neutral neutral active species are produced inside the gas pipe 21. The generated ions and neutral active species are carried by the extension portion 211 of the gas pipe 21, enter the inside of the processing container 5, uniformly diffuse inside the processing container 5, and reach the substrate 30. Then, depending on the ions and neutral active species that have arrived, the substrate 3
The desired processing of 0 is performed. That is, for example, the neutral active species gas such as Freon reacts with the exposed material on the surface of the substrate 30 to perform the etching process. As described above, in the apparatus of the present embodiment, microwaves are coupled to the plasma forming gas at two positions facing the substrate 30 to form two plasmas, and ions generated by these two plasmas Since the neutral neutral active species are evenly extracted and used in the extension portion 211 of the gas pipe 21 as the guide means, the substrate 30 can be uniformly processed.

In the above embodiment, as described in claim 7, the transmission line 1 on the input side of the plasma formation region 7 is provided.
Placing a matcher on top provides even more desirable results. That is, although the matching device is frequently used in a normal microwave transmission circuit, since the gas pipe 21 made of an insulating material is penetrated through the branched rectangular waveguide 12 as in the present embodiment, a load is not required. The impedance has changed greatly compared to the original design. Therefore, unless proper matching is performed, there arises a problem that transmission loss increases. Although not shown in FIG. 1, the matching unit is achieved by providing a stub matching circuit or the like on the transmission line 1 on the input side of the branching unit 13, for example. Further, in the above-mentioned embodiment, when the isolator is arranged on the transmission line 1 as described in claim 8, further desirable result is obtained. That is, by disposing the isolator on the transmission line 1 so that the reflected wave does not return to the micro oscillator, the life of the oscillator can be extended. When the matching unit is arranged, this isolator is preferably arranged on the transmission line 1 on the input side (the side closer to the microwave oscillator) than the matching unit.

Next, a second embodiment of the present invention will be described. FIG. 3 is a schematic perspective view showing a second embodiment of the present invention. The above-described first embodiment has a structure in which the end of the transmission path is branched into two, whereas the second embodiment is different in that it is branched into four. Hereinafter, the second embodiment will be described in detail while avoiding duplication of description.

In the second embodiment, as in the first embodiment, microwaves are transmitted by the transmission line 1 composed of the rectangular waveguide 11. The end of this rectangular waveguide 11 is shown in FIG.
As shown in FIG. 3, the branch portion 13 is formed and is branched into two branched rectangular waveguides 12. Specifically, the branching section 13 is an H-plane symmetric T-branch, and the transmitted microwave is branched into two branch rectangular waveguides 12 in phase. As shown in FIG. 3, the two branched rectangular waveguides 12 are formed in a U shape by forming two corners or vents, and the ends of each of them are opposed to each other below the branch portion 13. Further, each of the ends facing each other further has an H-plane symmetric T-branch, and two four-branch waveguides 14 are connected to each other and extend in the direction of the rectangular waveguide 11. Therefore, the microwaves sent through the branched rectangular waveguide 12 branch from the portion of the connection portion 141 to the respective four-branched waveguides 14 in the same phase and proceed to the four-branched waveguides 14
It is designed to reach the terminal short-circuit plate.

On the other hand, also in this second embodiment, the same gas pipe 21 as in the first embodiment is adopted. This gas pipe 21 penetrates each of the four-branch waveguides 14 and a total of four gas pipes are used. Each gas pipe 21 penetrates in the position of the antinode of the standing wave in each four-branch waveguide 14, as in the above-described embodiment. More generally, from the position of the terminal short-circuit plate of the four-branch waveguide 14, it is approximately (λ / 4).
The position on the input side is the penetration position by a distance of + (2 / λ) × m. It should be noted that λ is the resonance wavelength of the microwave and m is a positive integer. The four four-branch waveguides 14 are constructed in exactly the same manner, so that in this embodiment, four plasma forming regions 7 that operate similarly are arranged. Further, the gas introduction system 2 in the second embodiment is the same as that in the first embodiment except that the gas for plasma formation is introduced into the four gas pipes 21. still,
One gas transfer pipe may be branched into four and four gas pipes 21 may be connected. However, if the conductance may be reduced, two or four independent gas introduction systems 2 may be used. May be

Also in the present embodiment, the guide means is constituted by the extension portion 211 extending to the lower side of each gas pipe 21, and the ions and neutral active species generated at the penetrating portion to the four-branch waveguide 14 are kept as they are. It is carried to the processing container 5 below. And the extension 21 of the four gas pipes 21
Similarly to the first embodiment described above, the number 1 is evenly positioned with respect to the surface of the substrate 30 inside the processing container 5. That is, the lower end of each extension portion 211 is connected to the processing container 5 at a symmetrical position (more specifically, a square vertex position) with respect to the central axis of the substrate 30. Therefore, also in this second embodiment, each extension 21
The ions and neutral active species guided by 1 uniformly diffuse inside the processing container 5 and reach the substrate 30. The other constituent elements of each part are the same as those in the above-described first embodiment, and therefore description thereof will be omitted.

In the device of the second embodiment having the above-mentioned configuration, the transmitted microwave is branched into H plane symmetry T at the branching portion 13 and is branched and transmitted to the two branched rectangular waveguides 12. After that, the H-plane symmetric T-branch is again branched at the connecting portion 141 and transmitted to the four four-branch waveguides 14. Then, the transmitted microwaves pass through the respective wall surfaces of the four gas pipes 21 and are combined with the internal plasma forming gas, so that the plasma forming gas is brought into a plasma state. As a result, the ions and neutral active species generated by the plasma are guided by the extension portions 211 of the respective gas pipes 21 and enter the processing container 5, uniformly diffuse inside the processing container 5 and reach the substrate 30. , The surface of the substrate 30 is uniformly processed. Also in the second embodiment described above, the use of the matching device or the isolator in the transmission line 1 brings about the same preferable result as in the first embodiment. The matching device in the second embodiment may be arranged on the input side of the branch portion 13, and the isolator may be arranged on the input side of the four-branch waveguide 14 as a load.

In the above-mentioned two embodiments, as the uniform arrangement of the guide means for achieving the uniformity of the substrate processing, the example in which the end faces of the extension portions 211 are arranged symmetrically on the same plane is described. Any configuration can be adopted. Figure 4
[FIG. 8] is an explanatory view of another example of the uniform arrangement of the guide means, which is an example in which a hemispherical chamber is adopted as in the conventional apparatus shown in FIG. In addition, in FIG.
(A) is a side sectional view and (B) is a plan view. In this example,
Chamber (sometimes called a bell jar) 6
Has a plurality of introduction holes 61 formed at the same height on the circumferential surface thereof, and the end surface of each extension portion 211 has the introduction holes 6 respectively.
It is connected to part 1. Then, as shown in FIG. 4B, the introduction holes 61 are arranged in line symmetry around the center line 62, and the end faces of the extension portions 211 are arranged in center symmetry. There is. It is needless to say that the center line 62 is configured so as to coincide with a perpendicular line that stands up from the center of the surface of the substrate (not shown).

Finally, an embodiment of the constitution of claim 6 will be described. In both of the above-mentioned two embodiments, the transmitted microwave is branched and used. This has the effect that the microwave oscillator can be made one and the whole device can be made compact, and the cost of the device can be reduced. However, a plurality of microwave oscillators are used corresponding to the number of plasma formation regions 7, and the microwaves oscillated by the respective microwave oscillators are
It may be configured to transmit to each corresponding plasma forming region 7. With this structure, the microwave power transmitted to the rectangular branch waveguide 12 or the four-branch waveguide 14 becomes stronger, so that a high density of plasma causes abundant ions and neutral neutral activity. Seeds can be obtained and processed efficiently. In the case of this embodiment, the transmission line 1 is configured by arranging a plurality of waveguides in parallel, for example.

[0030]

As described above, in the invention described in claim 1 of the present application, microwaves are coupled to the plasma forming gas at a plurality of positions facing the substrate to form plasma, and the plasma is generated by the plurality of plasmas. Since the generated ions and neutral neutral active species are uniformly extracted and used by the guide means, uniform substrate processing becomes possible. Further, in the invention described in claim 2 or 3, in addition to the effect of claim 1, plasma can be formed by efficiently utilizing the transmitted microwaves, so that the efficiency of processing can be improved. The effect is obtained. In the invention according to claim 4,
In addition to the effect of claim 2 or 3, the guide means is formed by the extension of each gas pipe, so that an effect is obtained that the device has a simple structure. In addition, in the invention described in claim 5, in addition to the effect of claim 1, 2, 3 or 4, the number of microwave oscillators can be reduced, so that there is an effect that an inexpensive and compact device can be obtained. can get. Further, in the invention of claim 6, in addition to the effect of claim 1, 2, 3 or 4, more powerful microwave can be coupled to the plasma forming gas, so that abundant ions and neutral neutral The effect that the sexually active species can be obtained and the treatment can be efficiently performed is obtained. further,
In the invention according to claim 7, the above-mentioned claims 1, 2, 3,
In addition to the effects of 4, 5, or 6, transmission loss and the like in the microwave transmission path are reduced, and therefore, an effect that efficient processing is possible in this respect is obtained. Further, claim 8
In the invention described in claim 1, the above-mentioned claims 1, 2, 3, 4, 5, 6
In addition to the effect of 7 or 7, since the reflected wave of the microwave does not return to the microwave oscillator, the life of the oscillator becomes stable in the microwave transmission state, and stable processing can be performed.

[Brief description of drawings]

FIG. 1 is a schematic perspective view showing a first embodiment of the present invention.

FIG. 2 is an explanatory view of a penetrating portion of a gas pipe in the embodiment of FIG.

FIG. 3 is a schematic perspective view showing a second embodiment of the present invention.

FIG. 4 is an explanatory diagram of another example of uniform arrangement of guide means.

FIG. 5 is a schematic explanatory view of an example of a conventional plasma processing apparatus.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Transmission line 11 Rectangular waveguide 12 Branch rectangular waveguide 122 Termination short-circuiting plate 13 Branch part 14 Four branch waveguide 2 Gas introduction system 21 Gas pipe 211 Extension part 3 Substrate holder 30 Substrate 5 Processing container 7 Plasma formation region

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[Procedure amendment]

[Submission date] July 31, 1993

[Procedure Amendment 1]

[Document name to be amended] Statement

[Name of item to be corrected] 0022

[Correction method] Change

[Correction content]

In the above embodiment, as described in claim 7, if a matching device is arranged on the transmission line 1 on the input side of the plasma formation region 7, further desirable results can be obtained. That is, although the matching device is frequently used in a normal microwave transmission circuit, when plasma is formed inside the waveguide as in the present embodiment, the impedance changes greatly, so that the impedance changes. Placing a matcher for the purpose of compensating for ## EQU1 ## produces even more desirable results. Although not shown in FIG. 1, the matching unit is achieved by providing a stub matching circuit or the like on the transmission line 1 on the input side of the branching unit 13, for example. Further, in the above-mentioned embodiment, when the isolator is arranged on the transmission line 1 as described in claim 8, further desirable result is obtained. That is, by disposing the isolator on the transmission line 1 so that the reflected wave does not return to the micro oscillator, the life of the oscillator can be extended. When the matching unit is arranged, this isolator is preferably arranged on the transmission line 1 on the input side (the side closer to the microwave oscillator) than the matching unit.

[Procedure Amendment 2]

[Document name to be amended] Statement

[Name of item to be corrected] 0027

[Correction method] Change

[Correction content]

In the device of the second embodiment having the above configuration,
The transmitted microwave is branched into H plane symmetry T at the branching portion 13 and is branched and transmitted to the two branched rectangular waveguides 12. After that, the H-plane symmetric T-branch is again branched at the connecting portion 141 and transmitted to the four four-branch waveguides 14. Then, the transmitted microwaves pass through the respective wall surfaces of the four gas pipes 21 and are combined with the internal plasma forming gas, so that the plasma forming gas is brought into a plasma state. As a result, the ions and neutral active species generated by the plasma are guided by the extension portions 211 of the respective gas pipes 21 and enter the processing container 5, uniformly diffuse inside the processing container 5 and reach the substrate 30. , The surface of the substrate 30 is uniformly processed. Also in the second embodiment described above, the use of the matching device or the isolator in the transmission line 1 brings about the same preferable result as in the first embodiment. Since the main purpose of the matching device is to correct the change in impedance due to the formation of plasma as described above, it is necessary to provide one matching device on each input side of each plasma formation region. That is, one matching device is arranged at a position closer to the input side than the penetrating portion of the gas pipe 21 of each four-branch waveguide 14. Further, since the isolator protects the microwave oscillator as described above, when the matching device is arranged, the isolator is provided on the transmission line 1 on the input side of the matching device, and when the matching device is not arranged, the isolator is connected to the load. Also, it is sufficient if one is arranged on the transmission line 1 on the input side. That is, one isolator is arranged in the rectangular waveguide 11 that connects the microwave oscillator (not shown) and the branch portion 13.

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Claims (8)

[Claims] 1. A microwave generator comprising: a microwave oscillator; a transmission path for transmitting microwaves oscillated by the microwave oscillator; a gas introduction system for guiding a plasma forming gas; and a substrate holder for holding a substrate. Each of the plurality of plasma forming regions facing the substrate is formed so that a plurality of plasma forming regions, which are regions where microwaves are coupled to the working gas and plasma is formed, are formed at positions facing the substrate. To introduce microwaves to the plasma forming region, and the gas introducing system guides a plasma forming gas to each of these plasma forming regions. A plurality of guide means for guiding the substrate to the substrate held by the substrate holder are provided at even positions with respect to the surface of the substrate to be processed. Plasma processing device. 2. The transmission line is formed of a rectangular waveguide which is connected to the microwave oscillator and whose end is short-circuited by a terminal shorting plate, and the gas introduction system forms plasma inside a plurality of gas pipes. To introduce a gas for use,
Further, each of the gas pipes is arranged so as to penetrate the waveguide at the position of the antinode of the standing wave in the waveguide, and the gas pipe of the penetrated portion forms the plasma formation region, and at least The gas pipe of the penetrating portion is insulative.
The plasma processing apparatus according to. 3. A branched rectangular waveguide is connected to the end of the rectangular waveguide forming the transmission line to branch into a plurality of parts, and the gas pipe is arranged to penetrate each branched waveguide. The plasma processing apparatus according to claim 2, wherein the plasma processing apparatus is a plasma processing apparatus. 4. The plurality of gas pipes each have an extension portion extending downstream from a portion penetrating the waveguide or the cavity resonator toward the surface of the substrate to form the guide means. The plasma processing apparatus according to claim 2 or 3, wherein the extension portions of the respective gas pipes are evenly arranged with respect to the substrate. 5. The transmission path has a branching portion for branching a microwave, and branches the microwave oscillated from one microwave oscillator to transmit the microwave to the plurality of plasma formation regions. Claims 1, 2, 3 characterized
Or the plasma processing apparatus of item 4. 6. A plurality of the microwave oscillators are arranged corresponding to the number of the plasma formation regions, and the transmission lines are
5. The plasma processing apparatus according to claim 1, wherein the microwave is transmitted to each plasma formation region corresponding to each microwave oscillator. 7. The plasma processing apparatus according to claim 1, wherein a matching device is arranged on the transmission line on the input side of the plasma formation region. 8. An isolator is arranged on the transmission line.
The plasma processing apparatus according to 6 or 7.