JP2000096247A - Surface treating device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make the distribution of radicals of gaseous raw material uniform on a substrate, to make the film thickness on the substrate uniform and to eliminate trouble, such as unnecessary heat transfer to a reduction/expansion nozzle which can occur in the structure of the nozzle and film formation in the nozzle, by surely ejecting supersonic flow from the nozzle. SOLUTION: The gaseous raw material 7 and carrier gas 8 which are formed as plasma and are excited from the blowout port 10a of the plug nozzle 10 is ejected toward a plug slope 2a and are expanded along the conical slope of the plug 1. The streams of the gases 7, 8 intersect with each other at one point at the front end of the plug 2 and thereafter, the gases are introduced in the form of the supersonic plasma flow 11 uniform in the distribution of pressure into the substrate 5 arranged downstream of the plug nozzle 10. This flow collides against the substrate 5 and a film 6 is deposited thereon.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for surface-treating an object to be processed such as a substrate by forming or etching a functional thin film such as polycrystalline silicon, diamond, or CBN on the substrate.

[0002]

2. Description of the Related Art Conventionally, a raw material gas is converted into a plasma, and the plasma is jetted onto a substrate as a plasma jet through a reduction / enlargement nozzle (Laval nozzle), thereby forming a diamond thin film on the substrate. Techniques for performing surface treatment such as film formation have been adopted in the field of film formation processing.

In this case, in order to form a functional polycrystalline thin film of polycrystalline silicon, diamond, CBN, or the like at a high film forming rate with a high quality, a raw material gas as a raw material of the thin film is maintained in an excited state. It is necessary to reach the substrate in a short time while keeping it.

[0004] For this purpose, an arc discharge path is first generated by, for example, DC arc discharge, and thermal energy generated in the arc discharge path is given to a plasma forming gas. The plasma forming gas (gas to be converted into plasma) is, for example, a raw material gas (for example, a methane gas containing carbon which is a raw material for diamond) and a carrier gas (a gas for transporting the raw material gas. ). The raw material gas is heated,
By being converted into plasma, radicals in a highly reactive state are formed. The carrier gas is an atomic gas. The plasma forming gas excited by the arc discharge flows from the reduction / enlargement nozzle at a supersonic flow and reaches the substrate. As a result, a diamond thin film or the like is formed on the substrate.

Here, in order to uniformly generate the thickness of the diamond thin film in each part on the substrate, the pressure distribution on the substrate (the super It is necessary to make the pressure distribution on the substrate when the sonic flow collides) uniform at each part on the substrate, and to make the radical density of the source gas uniform at each part on the substrate.

If a subsonic flow (a flow below the sonic speed) is ejected from the outlet of the contraction / expansion nozzle, the pressure distribution on the substrate is such that the pressure becomes extremely high at the center of the nozzle, but increases as the distance from the nozzle center increases Is gradually reduced, resulting in a non-uniform distribution. For this reason, the radical density of the source gas also has the same non-uniform distribution, and although the film thickness is formed near the center of the nozzle, the film thickness is extremely small at the end of the substrate separated from the center of the nozzle. Only a non-uniform film thickness can be obtained. That is, the film formation quality deteriorates. Furthermore, at the end of the substrate where the radical density of the source gas is low, the source gas is lost by diffusion to the extent that the density is low. That is, there is a problem that the film formation rate is reduced because the source gas is lost by diffusion.

[0007] Japanese Patent Publication No. 3-16188 discloses a ratio P1 / P1 of the pressure P0 on the upstream side and the pressure P1 on the downstream side of the reduction / enlargement nozzle.
P0 is the critical pressure ratio, that is, A technique for performing a surface treatment such as film formation at a pressure ratio equal to or lower than the pressure ratio is disclosed.

However, the condition below the critical pressure ratio in the above equation (1) is only a necessary condition for making the flow in the throat portion of the nozzle sonic. Under the condition of equation (1), the flow at the nozzle outlet may become subsonic due to the formation of a vertical shock wave in the nozzle. For this reason, the film thickness of the thin film becomes unevenly distributed, and the source gas is lost due to diffusion, so that the film forming speed is reduced.

Accordingly, the applicant of the present application filed Japanese Patent Application No.
Japanese Patent Application No. 220204/97 filed an invention in which the pressures P1 and P0 are adjusted so that the pressure ratio P1 / P0 satisfies the condition represented by the following equation (2). Here, M is the Mach number at the exit surface of the reduction / enlargement nozzle, and γ is the specific heat ratio of the gas.

[0010] If the condition of the above equation (2) is satisfied, the vertical shock wave cannot theoretically exist in the nozzle, and a supersonic flow can be obtained at the nozzle outlet.

However, there is a problem that it is difficult to set the condition of the pressure ratio for obtaining the above-mentioned supersonic flow with the reduction / expansion nozzle, and the stability is not good. That is, if the condition of the above equation (2) is slightly deviated, a vertical shock wave is formed, and the flow at the nozzle outlet becomes a subsonic flow.

The reduction / enlargement nozzle includes a reduction portion having a gradually decreasing cross-sectional area, a throat portion having a minimum cross-sectional area,
And an enlarged portion whose downstream cross-sectional area gradually increases. In the enlarged portion, the cross-sectional area is gradually enlarged with a predetermined expansion angle.

However, in the case of the reduced-expanded nozzle, the condition of supersonic speed is determined by the ratio of the cross-sectional area at the throat portion to the cross-sectional area at the nozzle outlet. Therefore, it is necessary to secure a constant cross-sectional area at the nozzle outlet. Moreover, in order to prevent separation of the gas flowing inside the nozzle, the expansion angle in the enlarged portion cannot be made larger than a certain value. For this reason, the length of the enlarged portion of the reduction / enlargement nozzle has to be increased.

Since the gas passes through such a long enlarged portion, the area where the plasma gas contacts the inner wall of the nozzle becomes large. As a result, unnecessary heat transfer from the plasma gas to the nozzle occurs, and the activity of the plasma gas that has been activated is reduced. As a result, the source gas may return from the excited state to the ground state before reaching the substrate, so that the film forming process or the like cannot be performed efficiently.

Further, as the area of the nozzle becomes longer and the area where the plasma gas contacts the inner wall of the nozzle becomes larger, the chance of forming a film on the inner wall of the nozzle increases. For this reason, there is a problem in that the plasma gas is wasted, and the maintenance and maintenance of the nozzle requires time and cost.

The present invention has been made in view of the above-mentioned circumstances, and by uniformly ejecting a supersonic flow from a nozzle, the distribution of radicals of the raw material gas is made uniform on the substrate to make the film thickness on the substrate uniform. It is an object of the present invention to solve the problem of unnecessary heat transfer to the nozzle, which may occur due to the structure of the reduction / enlargement nozzle, and a problem such as film formation in the nozzle.

[0017]

Means for Solving the Problems and Action and Effect
In the first aspect of the present invention, a plasma-forming gas is turned into a plasma, and the plasma-forming gas is ejected as a supersonic flow through a nozzle toward the processing object, so that the processing object has a surface. In the surface treatment apparatus for processing, the nozzle is formed such that a flow is formed along a slope provided on an outer periphery of the plug and a plug having a slope formed so that the nozzle is tapered as the flow becomes downstream. A plug nozzle having an ejection port for ejecting the plasma-forming gas toward the plug slope; ejecting the plasma-forming gas from the ejection port; and forming the plasma-formed gas on the slope of the plug. The supersonic flow is guided to the object by expansion along.

According to a second aspect, in the first aspect, the plasma forming gas is a gas containing a raw material for surface treatment.

According to a third aspect of the present invention, in the first aspect, the plasma forming gas is a carrier gas, and the energy of the plasmatized carrier gas is given to a raw material gas serving as a raw material for surface treatment. The source gas is activated and guided to the object.

According to a fourth aspect of the present invention, in the third aspect of the present invention, a raw material gas outlet for discharging the raw material gas from the slope of the plug toward the outside of the plug is formed on the slope of the plug.

According to a fifth aspect of the present invention, in the third aspect of the present invention, a source gas jet port for jetting the source gas toward the outside of the plug from a downstream end portion of the plug is provided at a downstream end portion of the plug. It is characterized by having been formed.

According to a sixth aspect of the present invention, in the first aspect, a heating means for heating the plug is provided so that heat of the plasma-forming gas does not move to the plug side. Features.

According to a seventh aspect, in the third aspect, a heating means for heating the source gas in advance before the source gas is mixed with the carrier gas is provided.

According to an eighth invention, in the fourth invention or the fifth invention, a heating means for preheating the raw material gas is provided inside the plug before the raw material gas is mixed with the carrier gas. Features.

According to a ninth aspect, in the eighth aspect, a fin for increasing a contact area with the source gas is formed in a source gas passage inside the plug communicating with the source gas jet port. I do.

According to a tenth aspect, in the first aspect,
The plug is formed of a high heat resistant material.

According to an eleventh aspect, in the first aspect,
The plug nozzle is an annular plug nozzle including an outer cylindrical member and an inner plug, and an annular gap between the outer cylindrical member and the inner plug as the ejection port. A swirling means for swirling the plasma forming gas along the annular direction of the annular jet port.

In the twelfth invention, the plasma-forming gas is converted into plasma by arc discharge between an anode and a cathode, and the plasma-formed gas is directed to a workpiece as a supersonic flow through a nozzle. In the surface treatment apparatus for performing surface treatment on the object to be treated by jetting the nozzle, the nozzle is provided with a plug having a slope formed so as to be tapered as the flow becomes downstream, and the plug provided on the outer periphery of the plug. A jet nozzle for jetting the plasma-forming gas toward the plug slope so that a flow is formed along the slope of the plug nozzle, and jetting the plasma-forming gas from the jet port, By expanding the converted plasma forming gas along the slope of the plug, a supersonic flow is guided to the object.

According to a thirteenth aspect, in the twelfth aspect, one of the anode and the cathode for the arc discharge is disposed upstream of the plug, and the other pole is the plug.

According to a fourteenth aspect, in the twelfth aspect, the plug nozzle comprises an outer cylindrical member and an inner plug, and an annular member between the outer cylindrical member and the inner plug. An annular plug nozzle having an air gap as the ejection port, wherein one pole of the arc discharge anode and the cathode is the outer tubular member, and the other pole is the inner plug, Rotating means for forming an arc discharge path in the annular outlet between the cylindrical member and the inner plug, and rotating the arc discharge path along the annular direction of the annular outlet. It is characterized by being able to obtain.

According to a fifteenth aspect, in the fourteenth aspect, the rotating means for rotating the arc discharge path rotates the arc discharge path by applying a perpendicular force to the arc discharge path using a magnetic force. And things.

In a sixteenth aspect based on the fourteenth aspect, in the fourteenth aspect, the rotating means for rotating the arc discharge path includes a plurality of the outer cylindrical members or the inner plugs arranged along a ring direction of the annular outlet. By dividing the electrodes into electrodes and sequentially energizing the plurality of electrodes, an arc discharge path is sequentially formed along the annular direction of the annular ejection port.

[0033] In a seventeenth aspect based on the twelfth aspect, the plug nozzle comprises an outer tubular member and an inner plug, and an annular plug between the outer tubular member and the inner plug. An air gap is an annular plug nozzle serving as the ejection port, wherein the anode for the arc discharge, one of the cathodes is the outer cylindrical member, and the other is the inner plug, The outer cylindrical member or the inner plug is divided into a plurality of electrodes along the annular direction of the annular ejection port, and the plurality of electrodes are simultaneously energized to cause an arc discharge path to extend along the annular injection port. It is characterized in that it is formed at a plurality of locations along the ring direction of the outlet.

In an eighteenth aspect based on the twelfth aspect, in the twelfth aspect, the plug nozzle comprises an outer cylindrical member and an inner plug, and an annular member between the outer cylindrical member and the inner plug. An annular plug nozzle having an air gap as the ejection port, further comprising a swirl means for swirling the plasma forming gas along a ring direction of the annular ejection port.

According to a nineteenth aspect, in the twelfth aspect, the source gas is ejected from a position downstream of a portion where the arc discharge path is formed.

According to a twentieth aspect, in the nineteenth aspect, a source gas outlet for discharging the source gas from the slope of the plug toward the outside of the plug is formed on the slope of the plug.

According to a twenty-first aspect, in the nineteenth aspect, a source gas jet port for jetting the source gas from a front end portion on the downstream side of the plug toward the outside of the plug is provided.
The plug is formed at the downstream end portion.

In the twenty-second aspect, the plasma-forming gas is turned into a plasma, and the plasma-formed gas is ejected through a nozzle as a supersonic flow toward the workpiece, whereby the workpiece is processed. In a surface treatment apparatus for performing a surface treatment, the nozzle is provided with a plug having a slope formed so as to be tapered as the flow becomes downstream, and a flow along the slope of the plug which is annularly arranged along the outer periphery of the plug. A cluster-type plug nozzle having a plurality of cluster nozzles each of which ejects the plasma-forming gas toward the plug slope so as to be formed, and ejects the plasma-forming gas from the plurality of cluster nozzles, By expanding the plasma-forming gas along the slope of the plug, the supersonic flow can be treated. So that leads to things.

According to a twenty-third aspect, in the twenty-second aspect, the plasma-forming gas ejected from each of the plurality of cluster nozzles is a carrier gas, and a source gas serving as a raw material for surface treatment is supplied downstream of the plug. A raw material gas ejection port to be ejected toward the outside of the plug from the tip of the plug is formed at the tip of the downstream side of the plug, and the energy of the carrier gas converted into plasma is transferred from the tip of the plug at the downstream side of the flow. By giving the ejected source gas, the source gas is activated and guided to the object to be processed.

According to a twenty-fourth aspect, in the twenty-second aspect, a heating means for heating the plug is provided so that heat of the plasma-forming gas does not move to the plug side. Features.

According to a twenty-fifth aspect, in the twenty-second aspect, before the raw material gas is mixed with the carrier gas,
A heating means for preheating the source gas is provided inside the plug.

According to a twenty-sixth aspect, in the twenty-second aspect, the plasma forming gas is converted into plasma by an arc discharge between the anode and the cathode, and one of the anode and the cathode for the arc discharge is used. Are arranged in the cluster nozzle, and the other pole is the plug.

According to a twenty-seventh aspect, in the twenty-second aspect, the plasma forming gas is turned into plasma by arc discharge between the anode and the cathode, and one of the anode and the cathode for the arc discharge is used. Is the cluster nozzle, and the other pole is the plug.

In a twenty-eighth aspect based on the twenty-second aspect, the plasma forming gas is converted into plasma by arc discharge between an anode and a cathode, and an arc discharge path is formed in the cluster nozzle. I have to.

In the twenty-ninth aspect, the plasma-forming gas is turned into plasma, and the plasma-forming gas is ejected as a supersonic flow through a nozzle toward the processing object, whereby the processing object is processed. In a surface treatment apparatus for performing a surface treatment, the nozzle is an expansion deflection nozzle.

According to the first aspect of the present invention, as shown in FIG. 1, a plug 2 having a slope 2a formed so as to be tapered so that the flow becomes more downstream, and a slope 2a of the plug 2 provided on the outer periphery of the plug 2 A plug nozzle 10 having an ejection port 10a for ejecting the plasma forming gases 7, 8 toward the plug slope 2a so as to form a flow along the plug nozzle 10 is used.

For this reason, the plasma forming gases 7 and 8 are jetted from the jet port 10 a, and the plasma forming gases 7 and 8 are expanded along the slope 2 a of the plug 2 to form a supersonic flow 11. It is led to the processing object 5.

That is, in the plug nozzle 10, the boundary layer between the supersonic plasma flow 11 and the outside air changes according to the pressure of the outside air, but the supersonic flow is always obtained at the nozzle outlet without generating a vertical shock wave. In other words, the supersonic flow can be easily obtained and the stability is good without strictly managing the conditions for obtaining the supersonic flow as in the conventional reduction / enlargement nozzle. Therefore, the pressure (the pressure distribution on the substrate 5 when the supersonic flow 11 collides with the substrate 5) in each part from the central position 5c of the substrate 5 to the end 5e of the substrate 5 becomes uniform, Can be made uniform at each portion on the substrate 5. As a result, the thickness of the diamond thin film 6 formed on the substrate 5 can be made uniform in each part of the substrate 5, and the film formation quality can be significantly improved. In addition, the radical density of the source gas 7 decreases at the end 5e of the substrate 5, so that the source gas 7 is not lost by diffusion. As a result, it is possible to prevent a decrease in the film forming rate due to the loss of the source gas 7 due to diffusion. Further, the thermal load on the surface of the substrate 5 is also uniform, and thermal distortion of the substrate 5 is prevented.

Also, unlike the contraction / expansion nozzle, the plasma gas 7, 8 expands from the annular jet port 10 a around the nozzle 10 in the direction of the center axis of the nozzle 10, so that the gas 5, 8 A film can be formed.

Since the gas 7 and 8 reach the substrate 5 in a short time as the supersonic flow 11, the gas 7 and 8 are guided to the substrate 5 while maintaining the excited state without deactivating the plasma state. be able to. Therefore, a high-quality film can be formed at a high film-forming speed.

Further, since the length of the nozzle can be made shorter than that of the reduced / enlarged nozzle, the plug 2
The area where the plasma gas is brought into contact with the substrate can be reduced. Therefore, it is possible to prevent the inconvenience that the activity of the plasma gas is reduced due to the heat taken from the plasma gas by the nozzle 2, and the conversion efficiency from the raw material to the film can be increased.

Further, since the plug portion downstream of the ejection port 10a, which is the throat portion, is exposed to the outside, even if a film is formed on the plug portion downstream of the ejection port 10a, maintenance can be easily performed. It becomes possible.

In the second invention, as shown in FIG. 1, the plasma forming gas 7 is a gas containing a raw material for surface treatment.

According to the third aspect of the present invention, as shown in FIG. 2, the carrier gas 8 is used as a plasma forming gas, and the energy of the plasmatized carrier gas 8 is converted into the raw material gas 7 serving as a raw material for surface treatment. And the source gas 7 is activated and guided to the object 5.

According to the fourth invention, as shown in FIG. 7, the source gas 7 is jetted from the source gas jet port 10b formed on the slope 2a of the plug 2 toward the outside of the plug.

According to the fifth aspect of the present invention, as shown in FIG. 8A, the source gas 7 is supplied from the source gas jet port 10b formed at the tip 2b on the downstream side of the flow of the plug 2.
Spouted towards.

FIG. 8B shows the gas flow at this time. As shown in FIG. 8B, the flow G of the source gas 7 jetted from the jet port 10b is confined by the flow I of the supersonic plasma flow 11 of the carrier gas 8 on the outside. Therefore, the source gas 7 efficiently reaches the substrate 5 without diffusing outward.

When the source gas 7 collides with the substrate 5, it diffuses outward along the surface 5 a of the substrate 5 while forming a horizontal flow H in the figure. At this time, the source gas 7 collides with the flow I of the supersonic plasma flow 11 at the end J of the substrate 5. Therefore, the source gas 7 can be sufficiently excited not only at the center portion L of the substrate 5 but also at the end portion J.

As described above, according to the fifth aspect, the flow G of the source gas 7 reaches the substrate 5 so as to be wrapped in the flow I of the supersonic plasma flow 11 on the outside. Diffusion can be further prevented ("wrapping effect"). That is, the prevention of the diffusion increases the chance that the raw material contributes to film formation, and increases the film formation rate at which the raw material is converted into a film. When the conventional reduction / enlargement nozzle is used, the above-mentioned wrapping effect cannot be obtained,
Although the source gas 7 (radicals of the source gas 7) collides with the substrate 5 and is reflected instead of adhering to the substrate 5 and there is a problem that many sources do not contribute to film formation. According to the fifth invention, this is solved. Also, since the thermal pinch effect, which is a feature of arc jets, can be prevented,
A large-area substrate 5 can be formed.

In order to obtain the above-mentioned "wrapping effect", the position of the surface 5a of the substrate 5 is set at a height higher than the position of the virtual cone vertex F of the plug 2 as shown by the arrow Z in FIG. Desirably.

According to the fifth aspect of the present invention, the source gas 7 is sufficiently excited not only at the center portion L of the substrate 5 but also at the end portion J, so that the radical density in each portion of the substrate 5 can be made uniform. it can. For this reason, the thickness of the film 6 can be made uniform in each part of the substrate 5.

According to the sixth aspect of the present invention, as shown in FIG. 1A, the plug 2 is heated by the heating means 14, and the heat of the plasma-forming gases 7, 8 is converted to the side of the plug 2. Movement is prevented.

According to the seventh aspect, as shown in FIG. 8A, before the raw material gas 7 is mixed with the carrier gas 8,
The source gas 7 is previously heated by the heating means 14. This improves the conversion efficiency of the raw materials into radicals.

According to the eighth aspect of the present invention, as shown in FIG. 8A, before the raw material gas 7 is mixed with the carrier gas 8 by the heating means 14 provided inside the plug 2, 7 is preheated.

According to the ninth invention, FIGS.
As shown in FIG. 7, a fin 21a is formed in the source gas passage 21 inside the plug 2 communicating with the source gas outlet 10b, and the contact area with the source gas 7 is increased. Thereby, the efficiency of heat transfer from the heating means 14 to the source gas 7 is improved.

In the tenth aspect, the plug 2 is formed of a high heat-resistant material. As a result, even if the temperature becomes high at the nozzle outlet, it is possible to avoid the deformation and the erosion.

According to the eleventh invention, FIG.
As shown in (b) and (c), the plug nozzle 10 includes an outer tubular member 3 and an inner plug 2, and has an annular shape between the outer tubular member 3 and the inner plug 2. An annular plug nozzle having an opening as the ejection port 10a is formed. Then, by the turning means 20, the annular direction D of the annular ejection port 10a is set.
The plasma forming gases 7, 8 are swirled along. The density of the gas 7, 8 in each part in the same annular direction can be made uniform by the gas 7, 8 turning along the annular direction D of the annular ejection port 10a.

According to the twelfth aspect, the supersonic flow 11 is guided to the workpiece 5 using the plug nozzle 10 as in the first aspect.

Further, as shown in FIG.
The arc discharge 12 in between converts the plasma forming gas 8 into plasma.

According to the thirteenth aspect, as shown in FIG. 3, one pole 15 of the anode and the cathode for arc discharge is arranged on the upstream side of the plug 2 and the other pole is the plug 2. Thus, an arc discharge path 12 is formed upstream of the plug 2.

According to the fourteenth aspect, as shown in FIGS. 4 (a) and 5 (b), the plug nozzle 10 comprises the outer cylindrical member 3 and the inner plug 2, The annular gap between the cylindrical member 3 and the inner plug 2 is formed by
0a, which is an annular plug nozzle. One of the anode and cathode for arc discharge is an outer cylindrical member 3, and the other is an inner plug 2, between the outer cylindrical member 3 and the inner plug 2. Annular spout 10a
Then, an arc discharge path 12 is formed.

Then, the arc discharge path 12 is rotated by the rotating means 16 along the annular direction E of the annular ejection port 10a. This makes it possible to uniformly heat the gases 7 and 8 at each part in the annular direction of the annular jet port 10a, to make the degree of plasma uniform, and to form a symmetrical plasma jet flow from the center of the nozzle 10. Can be.

According to the fifteenth aspect, as shown in FIGS. 4 (a) and 5 (b), a force E perpendicular to the arc discharge path 12 (current) is generated by the rotating means 16 using magnetic force.
Is added, and the arc discharge path 12 is rotated.

According to the sixteenth aspect, FIG.
As shown in (b), the outer cylindrical member 3 or the inner plug 2 is divided into a plurality of electrodes 3a, 3b, 3c, 3d along the annular direction of the annular ejection port 10a.
The arc discharge paths 12a, 12b, 12c, and 12d are sequentially formed along the ring direction E of the annular ejection port 10a by sequentially energizing the electrodes a, 3b, 3c, and 3d.

According to the seventeenth aspect, as shown in FIG. 6, one of the anode and the cathode for arc discharge is the outer cylindrical member 3, and the other is the inner plug 2 and the inner plug 2. Is done. Then, the outer cylindrical member 3 or the inner plug 2 is connected to the plurality of electrodes 3a, 3a along the annular direction of the annular ejection port 10a.
b, 3c, 3d and a plurality of electrodes 3a, 3b, 3
The arc discharge paths 12a, 12b, 12c, and 12d are formed by the energization of the c.
It is formed at a plurality of places along the ring direction of a.

According to the eighteenth aspect, FIG.
As shown in (b) and (c), the plug nozzle 10 includes an outer tubular member 3 and an inner plug 2, and has an annular shape between the outer tubular member 3 and the inner plug 2. An annular plug nozzle having an opening as the ejection port 10a is formed. Then, by the turning means 20, the annular direction D of the annular ejection port 10a is set.
The plasma forming gases 7, 8 are swirled along. The gas 7, 8 is swirled in the annular direction D of the annular ejection port 10a, so that the density of the gas 7, 8 in each part in the annular direction can be made uniform, and the arc discharge condition is made the same in each part in the annular direction. be able to.

According to the nineteenth aspect, as shown in FIG. 7, the source gas 7 is jetted from the downstream (10b) of the portion 10a where the arc discharge path 12 is formed. Since the activated source gas 7 is not present at the discharge point, rapid erosion and consumption of the discharge electrode material (for example, tungsten) due to the activated source gas 7 being present at the discharge point are prevented. can do.

According to the twentieth aspect, as shown in FIG. 7, as shown in FIG. 7, the source gas 7 flows from the source gas jet port 10b formed on the slope 2a of the plug 2 toward the outside of the plug. It is gushing.

According to the twenty-first aspect, as shown in FIG. 8 (a), the source gas 7 is supplied from the source gas jet port 10b formed at the tip 2b on the downstream side of the flow of the plug 2. Spouted towards.

According to the twenty-second aspect, similarly to the first aspect, the supersonic flow 11 is generated by using the plug nozzle
It is led to.

However, as shown in FIG.
As 0, a cluster type plug nozzle is used. As shown in FIGS. 11A and 11B, the cluster type plug nozzle 10 has a slope 2 that is tapered toward the downstream side.
The plasma forming gas 8 is ejected toward the plug slope 2a such that a flow is formed along the slope 2a of the plug 2 and the plug 2 on which the "a" is formed. The plug nozzle includes a plurality of cluster nozzles 24.

Here, the annular plug nozzle and the cluster plug nozzle will be compared.

In the annular plug nozzle shown in FIG. 1, an annular gap having a width d (for example, 0.5 mm) is formed by the outer nozzle member 3 and the inner plug 2, so that the annular ejection port 10a having the width d is formed. Has formed. However, in order to obtain an accurate value d uniformly in each part in the ring direction, the plug 2 and the nozzle member 3 are required.
It is necessary to control the gap with the high precision, and extremely sophisticated processing is required. In practice, the value of the width d cannot be obtained uniformly in each part in the ring direction because of the restriction on the processing accuracy.

On the other hand, in the cluster type plug nozzle, since the ejection port 10a of the cluster nozzle 24 has a small circular shape, the diameter of the ejection port 10a of the cluster nozzle 24 is set to a value d.
It is very easy to process accurately. For this reason, in the cluster type plug nozzle, each ejection port 10a having a diameter d can be uniformly obtained without error in the ring direction around the plug 2.

Thus, if a cluster type plug nozzle is used, the diameter d of each of the ejection ports 10a around the plug 2 becomes uniform, so that a symmetric plasma jet flow can be formed when viewed from the center of the plug 2. In other words, gas excitation by plasma is uniform, and a uniform plasma flow can be obtained. In addition, since the direction of the plasma flow is accurately determined, the supersonic plasma flow 11 can be accurately jetted to a place where surface treatment is desired.

Further, since the diameter d of each ejection port 10a around the plug 2 can be accurately obtained, the sectional area A1 of the throat portion of the plug nozzle 10 can be adjusted with high accuracy. For this reason, the target performance can be obtained and the stable supersonic plasma flow 11 can be injected.

Further, since the cluster type plug nozzle 10 is an assembly of the individual cluster nozzles 24,
There is an advantage that a large area can be simultaneously formed as compared with the case where the cluster nozzle 24 is used alone.

According to the twenty-third aspect, as shown in FIG. 10, the carrier gas 8 is ejected from each of the plurality of cluster nozzles 24 as a plasma forming gas. Then, a raw material gas 7 serving as a raw material for the surface treatment is jetted toward the outside of the plug from a raw gas jet port 10b formed at the distal end 2b on the downstream side of the flow of the plug 2.

For this reason, the carrier gas 8 converted into plasma
Energy of the plug 2 at the downstream end 2 of the plug 2
The raw material gas 7 is supplied to the raw material gas 7 ejected from b, and the raw material gas 7 is activated and guided to the processing object 5.

According to the twenty-fourth aspect, as shown in FIG. 10, the plug 2 is heated by the heating means 14, and the heat of the plasma-forming gas 8 which has been turned into plasma is
Side movement is prevented.

According to the twenty-fifth aspect, as shown in FIG. 10, before the source gas 7 is mixed with the carrier gas 8 by the heating means 14 provided inside the plug 2, the source gas 7 is Preheated.

According to the twenty-sixth aspect, as shown in FIG. 10, one pole 25 of the anode and the cathode for arc discharge is disposed in the cluster nozzle 24, and the other pole is the plug 2. Thus, the plasma forming gas 8 is turned into plasma by the arc discharge 12 between the plug 2 and the electrode 25 in the cluster nozzle 24.

According to the twenty-seventh aspect, one of the anode and the cathode for arc discharge is used as the cluster nozzle 24, and the other is used as the plug 2, so that the plasma forming gas 8 Plasma is generated by the arc discharge 12 between the cluster nozzle 24 and the plug 2.

According to the twenty-eighth aspect, the arc discharge path 12 is formed in the cluster nozzle 24, and the plasma forming gas 8 is turned into plasma by the arc discharge 12 in the cluster nozzle 24.

According to the twenty-ninth aspect, as shown in FIG. 12, an expansion deflection nozzle 40 is used in place of the plug nozzle 10 of the first aspect, and the supersonic flow 11 is processed using the expansion deflection nozzle 40. Guided to object 5.

[0096]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a surface treatment apparatus according to the present invention will be described below with reference to the drawings.

In this embodiment, as the surface treatment,
FIG. 1 assuming that a diamond thin film is formed is an overall configuration diagram of the first embodiment, and shows an apparatus for vapor-phase growing a polycrystalline diamond thin film (or DLC film). FIG. 1A is a longitudinal sectional view, and FIG. 1B is a view of FIG.

As shown in FIG. 1, a raw material gas 7 serving as a raw material C of a thin film and a carrier gas 8 (methane C
A plug nozzle 10 is used as a nozzle for introducing a mixed gas of H4 and hydrogen H2). Note that an argon (Ar) gas may be used as the carrier gas 8.

Here, the plug nozzle 10 includes a plug 2 having a slope 2a formed so as to be tapered as the flow becomes more downstream, and a plug nozzle 2 provided on the outer periphery of the plug 2 to form the slope 2 of the plug 2.
outlet 10a for jetting plasma forming gases 7, 8 toward plug slope 2a so that a flow is formed along
This is a nozzle consisting of

The plug nozzle includes an annular plug nozzle and a cluster type plug nozzle described later. In the first embodiment, an annular plug nozzle is used.

The annular plug nozzle is defined as the inner plug 2
And an outer cylindrical nozzle member 3, a portion at the most downstream position of an annular gap having a width d formed by the outer nozzle member 3 and the inner plug 2 (FIG. 1 ( b)) is a nozzle having a gas ejection port 10a.

In the plug nozzle 10 of this embodiment, a plug 2 having a conical tip at the downstream side of the flow is used.

The plug 2 and the nozzle member 3 are made of a conductive material.

An AC voltage of a predetermined frequency is applied from an RF (high frequency) power supply 13 so that the plug 2 and the nozzle member 3 serve as electrodes. Therefore, a high-frequency discharge 30 is generated in a gap between the plug 2 and the nozzle member 3.

In the passage formed between the plug 2 and the nozzle member 3, the raw material gas 7 and the carrier gas 8
Is supplied.

Since the plug nozzle 10 is configured as described above, when the raw material gas 7 and the carrier gas 8 are supplied from the upstream, these gases 7, 8
It is heated by the discharge energy of 0 and turned into plasma.

The raw material gas 7 and the carrier gas 8, which have been turned into plasma and excited, are ejected toward the plug slope 2 a from the ejection port 10 a of the plug nozzle 10, and expand along the conical slope 2 a of the plug 2. At the tip of the plug 2, the flows of the gases 7 and 8 intersect at a single point. Thereafter, a supersonic plasma flow 11 having a uniform pressure distribution is led to the substrate 5 disposed downstream of the plug nozzle 10 and the substrate 5. Collide with

In the plug nozzle 10, the ejection port 10a
Is the throat portion, the gas passage area A1 at the throat portion 10a and the gas passage area A2 at the outlet of the nozzle 10
The pressure ratio is determined by the ratio of When the pressure ratio is determined, the expansion rate of the supersonic plasma flow 11 is determined. When the expansion rate increases, the supersonic plasma flow 11 expands outside the nozzle 10, and when the expansion rate decreases, the supersonic plasma flow 11 is narrowed inside the nozzle 10.

In the plug nozzle 10, the boundary layer between the supersonic plasma flow 11 and the outside air changes according to the pressure of the outside air, but a supersonic flow is always obtained at the nozzle outlet without generating a vertical shock wave. In other words, the supersonic flow can be easily obtained and the stability is good without strictly controlling the conditions for obtaining the supersonic flow as in the conventional reduction / enlargement nozzle. For this reason, the pressure (the pressure distribution on the substrate 5 when the supersonic flow 11 collides with the substrate 5) in each part from the center position 5c of the substrate 5 to the end 5e of the substrate 5 becomes uniform, Can be made uniform at each portion on the substrate 5. As a result, the thickness of the diamond thin film 6 formed on the substrate 5 can be made uniform in each part of the substrate 5, and the quality of film formation can be drastically improved. Source gas 7
Is reduced at the end 5e of the substrate 5, so that the source gas 7 is not lost by diffusion. As a result, it is possible to prevent a decrease in the film forming rate due to the loss of the source gas 7 due to the diffusion. Further, the thermal load on the surface of the substrate 5 is also uniform, and thermal distortion of the substrate 5 is prevented.

Also, unlike the reduction / enlargement nozzles, the gasified gas 7, 8 expands from the annular jet port 10 a around the nozzle 10 in the direction of the center axis of the nozzle 10, so that the gas 5, 8 A film can be formed.

Since the gas 7, 8 reaches the substrate 5 in a short time as the supersonic flow 11, the gas 7, 8 is led to the substrate 5 while maintaining the excited state without deactivating the plasma state. be able to. Therefore, a high-quality film can be formed at a high film-forming speed.

Since the length of the nozzle can be made shorter than that of the reduced / enlarged nozzle, the plug 2
The area where the plasma gas is brought into contact with the substrate can be reduced. Therefore, it is possible to prevent the inconvenience that the activity of the plasma gas is reduced due to the heat taken from the plasma gas by the nozzle 2, and the conversion efficiency from the raw material to the film can be increased.

Further, since the plug portion downstream of the ejection port 10a, which is the throat portion, is exposed to the outside, even if a film is formed on the plug portion downstream of the ejection port 10a, maintenance can be easily performed. It becomes possible.

In the present embodiment, the heater 14 for heating the plug 2 is provided inside the conical portion at the tip of the plug 2 so as to prevent the heat of the plasma gases 7 and 8 from being transferred to the plug 2. Is built-in.

That is, the source gas 7 and the carrier gas 8 are turned into plasma by the generation of the high-frequency discharge 30, and the temperature of the gas becomes extremely high. For this reason, if the temperature of the plug 2 is kept low, heat transfer from the plasma gas 7, 8 to the plug 2 occurs, and the plasma gas 7,
The energy of 8 will decrease.

However, in this embodiment, the temperature of the plug 2 is increased by the heater 14, and the temperature difference between the plug 2 and the plasma gas 7 or 8 becomes small or almost zero. Therefore, heat transfer from the plasma gas 7, 8 to the plug 2 can be minimized. As a result, it is possible to minimize a decrease in the activity of the plasma gas due to the heat transfer to the plug 2. The heater 14 can be provided not on the inside of the plug 2 but on the surface of the plug 2.

When a silicon film is formed on the substrate 5, monosilane S is used as the source gas 7 and the carrier gas 8.
What is necessary is just to supply the mixed gas of iH4 and hydrogen H2 into the nozzle 10 from the upstream.

In the case of performing an etching process, an etching gas may be supplied into the nozzle 10 from the upstream. Since the etching gas is a high-speed plasma flow having directionality by the plug nozzle 10, anisotropic etching can be performed.

In each of the embodiments described below, it is assumed that the diamond thin film 6 is formed on the substrate 5.
Of course, similarly to the first embodiment described above, the present invention may be applied to the case where a film other than diamond is formed, or to the case where various surface treatments such as etching are performed.

Next, a second embodiment will be described with reference to FIG. It should be noted that the description of the same components as those of the first embodiment already described will not be repeated.

In the annular plug nozzle 10 of the second embodiment, a cylindrical cap 4 is further provided outside the nozzle member 3. Therefore, a gap is formed between the nozzle member 3 and the cap 4. That is, the plug nozzle 10 of the present embodiment has a triple cylindrical structure.

In this embodiment, the plug 2 and the nozzle member 3
The carrier gas 8 is supplied from the upstream to the passage formed between them. On the other hand, the raw material gas 7 is supplied from the upstream to the passage formed between the nozzle member 3 and the cap 4. The raw material gas 7 is supplied from the ejection port 10 b at the most downstream position of the passage formed between the nozzle member 3 and the cap 4 to the slope 2 of the plug 2.
It is jetted toward a.

In this embodiment, a DC voltage is applied between the nozzle member 3 and the plug 2 by the DC power supply 9 between the nozzle member 3 as the anode and the plug 2 as the cathode. Therefore, an arc discharge path 12 is formed between the plug 2 and the nozzle member 3 and near the ejection port 10a.

A magnet 16 is annularly disposed on the outer periphery of the plug nozzle 10 and near the vertical position where the arc discharge path 12 is formed.

Since the plug nozzle 10 is configured as described above, when the carrier gas 8 is supplied from the upstream,
These carrier gases 8 are heated by the discharge energy of the DC arc discharge and turned into plasma.

The carrier gas 8 which is turned into plasma and excited from the outlet 10a of the plug nozzle 10 is ejected toward the plug slope 2a, and the conical slope 2a of the plug 2 is formed.
Inflates along. Then, the flow of the gas 8 crosses at one point at the tip of the plug 2, and thereafter becomes a uniform supersonic plasma flow 11, is guided to the substrate 5 disposed downstream of the plug nozzle 10, and collides with the substrate 5. On the other hand, the source gas 7 is supplied from the upstream of the nozzle 10 and is jetted from the jet port 10b toward the plug slope 2a so as to be blown onto the supersonic plasma flow 11 of the carrier gas 8.

As a result, the source gas 7 is mixed into the supersonic plasma flow 11 of the carrier gas 8, whereby the energy of the carrier gas 8 which has been turned into plasma is given to the source gas 7. Therefore, the temperature of the source gas 7 becomes high and the source gas 7 is activated. Then, the radicalized source gas 7 is guided to the substrate 5, and radicals of the source gas 7 cause a chemical reaction on the substrate 5, whereby a diamond thin film 6 is formed on the substrate 5.

Since the plug nozzle 10 is used in the present embodiment as in the first embodiment, a supersonic flow can always be obtained at the nozzle outlet without generating a vertical shock wave.
For this reason, the diamond film 6 can be formed to have a uniform thickness, and a reduction in the film formation rate due to the diffusion of the source gas 7 can be prevented.

Further, in the present embodiment, the arc discharge path 12 can be rotated along the ring direction of the annular ejection port 10a by the magnetic force of the magnet 16, whereby the plasma is generated at each part of the annular ejection port 10a in the ring direction. The degree of formation can be made uniform.

That is, FIG. 5B is a view of FIG. 2 viewed from the direction of arrow C.

Here, assuming that the magnet 16 is not provided, the arc discharge path 12 formed by the DC arc discharge is likely to form an arc along the ring direction of the ejection port 10a.
It is formed only at the point.

In this embodiment, the magnet 16 is connected to the ejection port 10a.
Are applied in the direction perpendicular to the arc discharge path 12 (current path), that is, in the direction of the ring. Therefore, the arc discharge path 12 is rotated along the annular direction of the annular ejection port 10a as shown by the arrow E. Therefore, an effect equivalent to the formation of a large number of arc discharge paths 12 in each part of the annular outlet 10a in the ring direction is obtained, and the gas 8 is uniformly heated in each part of the annular outlet 10a in the ring direction. Thus, the degree of gasification of the gas 8 can be made uniform. That is, the carrier gas 8 can be reliably heated and turned into thermal plasma, and a symmetrical plasma jet flow can be formed when viewed from the center of the nozzle 10. The magnet 16 may be a permanent magnet or an electromagnet, regardless of the type of magnet. In this embodiment, the magnet 16 is provided outside the plug nozzle 10, but may be provided inside the plug nozzle 10. , May be arranged both outside and inside the plug nozzle 10.

Although the DC power supply 9 is used in this embodiment, an AC power supply may be used instead of the DC power supply.

Further, the second embodiment shown in FIG.
It is also possible to carry out the configuration by appropriately combining the embodiments. In the configuration shown in FIG. 2 in which the gas is converted into plasma by the DC arc discharge, the raw material gas 7 is formed in the same manner as in FIG.
And the carrier gas 8 may be supplied to the same passage.

A heater 14 similar to that shown in FIG. 1 may be provided on the inner surface of the cap 4 or the outer surface of the nozzle member 3 shown in FIG. The heater 14 is used to heat the source gas 7 before mixing the source gas 7 into the carrier gas 8. If the raw material gas 7 is heated and given energy before the energy of the carrier gas 8 is applied to the raw material gas 7, the conversion efficiency of the raw material into radicals is improved, and the film formation efficiency can be further improved. Hereinafter, each embodiment for converting a gas into plasma by arc discharge will be further described.

FIG. 3 shows a third embodiment in which an arc discharge is generated on the upstream side of the plug 2. It should be noted that the description of the same components as those of the above-described embodiment will not be repeated.

In the third embodiment, an electrode member 15 serving as a cathode for arc discharge is disposed upstream of the plug 2 and inside the nozzle member 3. Nozzle member 3
The plug 2 is electrically connected to the plug 2 by a connecting member 17. Then, a DC voltage is applied from the DC power source 9 between the nozzle member 3 and the plug 2 and the electrode member 15 with the electrode member 15 serving as a cathode and the electrically connected nozzle member 3 and plug 2 serving as an anode. Therefore, an arc discharge path 12 is formed between the plug 2 and the electrode member 15. The connecting member 17 also functions as a member that mechanically connects the plug 2 and the nozzle member 3 to connect and fix the plug 2 to the nozzle member 3.

In this embodiment, the source gas 7 and the carrier gas 8 are supplied from a passage formed upstream of the plug 2.

Since the plug nozzle 10 is configured as described above, when the source gas 7 and the carrier gas 8 are supplied from the upstream of the plug 2, these gases 7, 8 are generated between the electrode member 15 and the nozzle member 3. Through the passage formed between them,
It reaches between the plug 2 and the electrode member 15 and is heated by the discharge energy of the DC arc discharge and turned into plasma.

The gasified gases 7 and 8 are led to an annular passage formed by the plug 2 and the nozzle member 3 and viewed from the direction of arrow C in FIG.

Here, according to the present embodiment, the gases 7, 8
Is converted into plasma upstream of the plug 2, so that the degree of plasma conversion of the gases 7, 8 can be made uniform.

If one of the plug 2 and the nozzle member 3 is used as an anode and the other is used as a cathode and a DC voltage is applied between the anode and the cathode, as described above, the annular ejection port 1 is used.
The arc discharge path 12 is formed only at one point in the ring direction of 0a. Therefore, the gas 7, 8 is sufficiently converted into plasma only in a part of the annular ejection port 10a in the ring direction, and the degree of plasma generation is non-uniform.

In this embodiment, however, the gas 7, 8 is turned into plasma by forming the arc discharge path 12 before the passage of the gas 7, 8 becomes an annular passage, that is, in the passage upstream of the plug 2. Therefore, the gases 7 and 8 can be uniformly heated, and the degree of plasma generation can be prevented from being uneven. In other words, the carrier gas 8 and the source gas 7 can be reliably heated and turned into thermal plasma, and a symmetrical plasma jet flow can be formed when viewed from the center of the nozzle 10.

The raw material gas 7 and the carrier gas 8 which are turned into plasma and excited from the ejection port 10a of the plug nozzle 10
Is ejected toward the plug slope 2 a and expands along the conical slope 2 a of the plug 2. Then, the flows of the gases 7 and 8 intersect at one point at the tip of the plug 2, and thereafter become a uniform supersonic plasma flow 11, are guided to the substrate 5 disposed downstream of the plug nozzle 10, and collide with the substrate 5.

As a result, the radicalized source gas 7 can be guided to the substrate 5, and the radical of the source gas 7 causes a chemical reaction on the substrate 5 to form a diamond thin film 6 on the substrate 5.

Also in this embodiment, since the plug nozzle 10 is used, a supersonic flow can always be obtained at the nozzle outlet without generating a vertical shock wave, as in the above-described embodiments.
For this reason, the thickness of the diamond film 6 can be made uniform, and a decrease in the film formation rate due to the diffusion of the source gas 7 can be prevented.

In the third embodiment, the mixed gas of the source gas 7 and the carrier gas 8 is supplied from the upstream of the nozzle 10 to the same passage in the nozzle 10. The raw material gas 7 that has passed through another passage may be mixed into the carrier gas 8 that has been turned into plasma by supplying the gas into the nozzle passage from upstream of the carrier gas 10. That is, the source gas 7 is mixed with the supersonic plasma flow 11 of the carrier gas 8, so that the energy of the carrier gas 8 that has been turned into plasma is given to the source gas 7. Therefore, the temperature of the source gas 7 becomes high and the source gas 7 is activated. Then, the radicalized source gas 7 is guided to the substrate 5, and radicals of the source gas 7 cause a chemical reaction on the substrate 5, whereby a diamond thin film 6 is formed on the substrate 5.

Although the DC power supply 9 is used in this embodiment, an AC power supply may be used instead of the DC power supply.

It is also possible to implement the third embodiment shown in FIG. 3 and the above-described embodiments by appropriately combining them. For example, a heater 14 similar to that of FIG. 1 may be provided inside the plug 2 of FIG.

FIG. 4 shows a fourth embodiment in which the arc discharge path is rotated using a magnet and the gas is swirled in the same rotation direction. It should be noted that the description of the same components as those of the above-described embodiment will not be repeated.

FIG. 4A is a longitudinal sectional view, and FIG.
4A is a cross-sectional view taken along the line AA of FIG. 4A, and FIG. 4C is a view of FIG. FIG. 4
(A) is BB sectional drawing of FIG.4 (b).

As shown in these figures, the plug nozzle 10 of the fourth embodiment comprises an inner plug 2 and an outer cylindrical nozzle member 3 as in the first embodiment shown in FIG. Have been.

As shown in FIGS. 4A and 4B, the plug 2
A cylindrical insulator 18 is interposed between the plug member 2 and the nozzle member 3, and electrically disconnects the plug 2 from the nozzle member 3. Then, a DC voltage is applied from a DC power supply 9 between the nozzle member 3 and the plug 2 using the plug 2 as a cathode and the nozzle member 3 as an anode. Therefore, an arc discharge path 12 is formed between the nozzle member 3 and the plug 2 and in the vicinity of the gas ejection port 10a where the insulator 18 does not exist.

As shown in FIG. 4B, a cylindrical insulator 1
At 8, passages 19 for passing the source gas 7 and the carrier gas 8 from upstream to downstream are formed at several places (for example, four places) along the circumferential direction of the cylinder. The passage 19 and the ejection port 10a are connected by a passage 20. The passage 20 is formed with an inclination such that the gases 7 and 8 flowing from the passage are swirled along the annular direction of the annular ejection port 10a.

In the present embodiment, the source gas 7 and the carrier gas 8 are supplied into the passage 19 from the upstream of the nozzle 10.

Since the plug nozzle 10 is configured as described above, when the source gas 7 and the carrier gas 8 are supplied from upstream of the nozzle 10, these gases 7 and 8 are injected through the passages 19 and 20. It reaches the exit 10a. Then, the gases 7 and 8 are heated by the discharge energy by the DC arc discharge and are turned into plasma. Then, the gasified gas 7, 8 is jetted from the jet port 10a.

Here, the gases 7, 8 flowing from the passage 10 are:
As shown by an arrow D in FIG.
Turns along the ring direction. The gas 7, 8 is swirled along the annular direction of the annular ejection port 10a, whereby the density of the gas 7, 8 in each part in the annular direction can be made uniform, and the arc discharge conditions in each part in the annular direction can be made uniform. be able to. As a result, arc discharge is stably generated at the ejection port 10a.

Further, in the present embodiment, similarly to the second embodiment shown in FIG. 2, the magnet 16 is annularly formed on the outer periphery of the plug nozzle 10 and near the vertical position of the nozzle where the arc discharge path 12 is formed. It is arranged. Therefore, magnet 1
The magnetic force of 6 causes the arc discharge path 12 to rotate along the annular direction of the annular ejection port 10a (see FIG. 5B). This makes it possible to uniformly heat the gases 7 and 8 at each part in the annular direction of the annular jet port 10a, to make the degree of plasma uniform, and to form a symmetrical plasma jet flow from the center of the nozzle 10. Can be.

That is, according to the present embodiment, the ejection port 10a
In this case, the arc discharge is generated stably and the arc discharge path 12 is rotated, so that a uniform plasma flow can be reliably ejected from the ejection port 10a.

The source gas 7 and the carrier gas 8 which are turned into plasma and excited from the ejection port 10a of the plug nozzle 10
Is ejected toward the plug slope 2 a and expands along the conical slope 2 a of the plug 2. Then, the flows of the gases 7 and 8 intersect at one point at the tip of the plug 2, and thereafter become a uniform supersonic plasma flow 11, are guided to the substrate 5 disposed downstream of the plug nozzle 10, and collide with the substrate 5.

As a result, the radicalized source gas 7 can be guided to the substrate 5, and the radical of the source gas 7 causes a chemical reaction on the substrate 5 to form a diamond thin film 6 on the substrate 5.

Also in this embodiment, since the plug nozzle 10 is used, a supersonic flow is always obtained at the nozzle outlet without generating a vertical shock wave, as in the above-described embodiments.
For this reason, the thickness of the diamond film 6 can be made uniform, and a decrease in the film formation rate due to the diffusion of the source gas 7 can be prevented.

In the fourth embodiment, the mixed gas of the source gas 7 and the carrier gas 8 is supplied from the upstream of the nozzle 10 to the same passage 19 in the nozzle 10, but only the carrier gas 8 is supplied. The raw material gas 7 that has passed through another passage may be mixed into the carrier gas 8 by supplying the gas from the upstream of the nozzle 10 to the passage 19 inside the nozzle. That is, the source gas 7 is mixed with the supersonic plasma flow 11 of the carrier gas 8, so that the energy of the carrier gas 8 that has been turned into plasma is given to the source gas 7. Therefore, the temperature of the source gas 7 becomes high and the source gas 7 is activated. Then, the radicalized source gas 7 is guided to the substrate 5, and radicals of the source gas 7 cause a chemical reaction on the substrate 5, whereby a diamond thin film 6 is formed on the substrate 5.

Further, in this embodiment, the DC power supply 9 is used, but an AC power supply may be used instead of the DC power supply.

Further, the fourth embodiment shown in FIG. 4 and each of the above-described embodiments can be appropriately combined and implemented. For example, a heater 14 similar to that of FIG. 1 may be provided inside the plug 2 of FIG.

In the fourth embodiment, the arc discharge path 12 is rotated by the magnetic force of the magnet 16;
As shown in (a), an electric circuit may be configured to rotate the arc discharge path 12 by switching a switch.

FIG. 5A is a view taken in the direction of arrow C in FIG. 4A.

As shown in FIG. 5A, the nozzle member 3
Is divided into four electrodes 3a, 3b, 3c, 3d via four insulators 18a, 18b, 18c, 18d. Switch SW for each electrode 3a, 3b, 3c, 3d
1, SW2, SW3, and SW4 are provided. Electrode 3
a is connected to the power supply 9 by closing the switch SW1.
, A voltage is applied from the power supply 9 by closing the switch SW2 to the electrode 3b, and a voltage is applied from the power supply 9 by closing the switch SW3 to the electrode 3c. , A voltage is applied from the power supply 9 by closing the switch SW4.

The switches SW1, SW2, SW3 and SW4 are sequentially closed by a switch control device (not shown).

For this reason, arc discharge paths 12a, 12b, 12c, and 12d are sequentially formed in each part of the annular ejection port 10a in the ring direction, and clockwise in the ring direction in the figure as shown by the arrow E in FIG. 5B. The arc discharge path 12 is rotated.

Although the nozzle member 3 is divided into a plurality of electrodes in the circuit shown in FIG. 5A, the plug 2 is divided into a plurality of electrodes and the plurality of electrodes on the plug 2 side are similarly energized sequentially. By doing so, the arc discharge path 12 may be rotated.

As shown in FIG. 6, an electric circuit may be formed to simultaneously form a plurality of arc discharge paths 12 in each part of the annular ejection port 10a in the annular direction.

FIG. 6 is a view taken in the direction of arrow C in FIG.

As shown in FIG. 6, the nozzle member 3
Via two insulators 18a, 18b, 18c, 18d,
It is divided into four electrodes 3a, 3b, 3c, 3d.
DC power supplies 9a, 9 for each of the electrodes 3a, 3b, 3c, 3d
b, 9c and 9d are provided. Therefore, a voltage is applied to the electrode 3a from the power supply 9a, a voltage is applied to the electrode 3b from the power supply 9b, a voltage is applied to the electrode 3c from the power supply 9c, and a voltage is applied to the electrode 3d from the power supply 9d.

For this reason, arc discharge paths 12a, 12b, 12c, and 12d are simultaneously formed in each part of the annular ejection port 10a in the ring direction, and the arc discharge path 12 is rotated as shown by an arrow E in FIG. 5B. An effect equivalent to the above is obtained.

In the circuit shown in FIG. 6, the nozzle member 3 is divided into a plurality of electrodes. However, the plug 2 is divided into a plurality of electrodes and a power supply is similarly provided for each of the plurality of electrodes on the plug 2 side. Thus, a plurality of arc discharge paths 12 may be formed in each part in the ring direction.

Next, a fifth embodiment in which a passage for the source gas 7 is provided in the plug 2 will be described with reference to FIG.

The configuration of the plug nozzle 10 in FIG. 7 is basically the same as the configuration in FIG. The difference is that the carrier gas 8 is supplied from the upstream into the passage 18, while the source gas 7 is supplied from the upstream into the passage 21 provided along the central axis of the plug 2. The plug nozzle 1 shown in FIG.
Only parts different from 0 will be described.

The passage 21 is branched into a plurality of passages at the conical portion of the plug 2. These plurality of branch passages are formed at a plurality of positions (e.g., 5
) Are connected to the ejection ports 10b, 10b,.

Since the plug nozzle 10 is configured as described above, when the carrier gas 8 is supplied into the passage 19 from the upstream of the nozzle 10, the carrier gas 8 is supplied to the passage 19,
It reaches the ejection port 10 a via the passage 20. The gas 8 is heated by the discharge energy of the DC arc discharge and turned into plasma. Then, the gas 8 converted into plasma is ejected from the ejection port 10a.

The carrier gas 8 which is turned into plasma and excited from the ejection port 10a of the plug nozzle 10 is supplied to the plug slope 2a.
And expands along the conical slope 2 a of the plug 2. The flow of the gas 8 intersects at one point at the tip of the plug 2, and thereafter, the uniform supersonic plasma flow 1
1 and the substrate 5 disposed downstream of the plug nozzle 10
And collides with the substrate 5.

Here, the source gas 7 is jetted out of the plug 2 from each jet port 10b formed on the plug slope 2a.

For this reason, the source gas 7 is mixed into the carrier gas 8 which has been turned into plasma on the plug slope 2a. That is, the source gas 7 is mixed with the supersonic plasma flow 11 of the carrier gas 8, so that the energy of the carrier gas 8 that has been turned into plasma is given to the source gas 7. Therefore, the temperature of the source gas 7 becomes high and the source gas 7 is activated. Then, the radicalized source gas 7 is guided to the substrate 5, and radicals of the source gas 7 cause a chemical reaction on the substrate 5, whereby a diamond thin film 6 is formed on the substrate 5.

In addition, since the raw material gas 7 is jetted from each position in the vertical direction of the plug slope 2a, the raw material gas is uniformly mixed in the process of expanding the plasmatized carrier gas 8 along the plug slope 2a.

Therefore, it is possible to make the thickness of the diamond film 6 more uniform than that of the structure of FIG. 4 and to prevent a decrease in the film forming speed due to the diffusion of the source gas 7.

In the present embodiment, the source gas 7 is ejected from the plug slope 2a downstream from the position where the arc discharge path 12 is formed (the ejection port 10a). That is, in the present embodiment, the activated source gas 7 does not exist at the discharge point. Therefore, rapid erosion and consumption of the discharge electrode material (for example, tungsten) due to the presence of the activated source gas 7 at the discharge point can be prevented.

In this embodiment, a plurality of gas outlets 10b are provided on the plug slope 2a, but the outlet 10b may be a single outlet.

Although the DC power supply 9 is used in this embodiment, an AC power supply may be used instead of the DC power supply.

It is also possible to implement the fifth embodiment shown in FIG. 7 and the above-described embodiments by appropriately combining them. For example, a heater 14 similar to that of FIG. 1 may be provided inside the plug 2 of FIG.

Next, a sixth embodiment in which the source gas 7 is ejected from the tip of the plug 2 will be described with reference to FIG.

The structure of the plug nozzle 10 shown in FIG.
It is basically the same as the configuration in FIG. However, a flat surface 2 b parallel to the substrate 5 is formed at the tip of the plug 2.
The difference is that b is formed. Hereinafter, only portions different from the plug nozzle 10 of FIG. 7 will be described.

The passage 21 formed along the center axis of the plug 2 communicates with the ejection port 10b at the tip of the plug 2.

Since the plug nozzle 10 is configured as described above, when the carrier gas 8 is supplied into the passage 19 from the upstream of the nozzle 10, the carrier gas 8 is supplied to the passage 19,
It reaches the ejection port 10 a via the passage 20. The gas 8 is heated by the discharge energy of the DC arc discharge and turned into plasma. Then, the gas 8 converted into plasma is ejected from the ejection port 10a.

The carrier gas 8 which is turned into plasma and excited from the ejection port 10a of the plug nozzle 10 is supplied to the plug slope 2a.
And expands along the conical slope 2 a of the plug 2. Then, the flow of the gas 8 intersects at one point at the virtual conical apex F of the plug 2, and thereafter becomes a uniform supersonic plasma flow 11, is guided to the substrate 5 disposed downstream of the plug nozzle 10, and collides with the substrate 5. I do.

Here, the source gas 7 is jetted toward the substrate 5 from the jet port 10 b at the tip of the plug 2.

For this reason, a part of the raw material gas 7 is mixed into the carrier gas 8 which has been turned into plasma downstream of the plug 2.
That is, the source gas 7 is mixed with the supersonic plasma flow 11 of the carrier gas 8, so that the energy of the carrier gas 8 that has been turned into plasma is given to the source gas 7. Therefore, the temperature of the source gas 7 becomes high and the source gas 7 is activated. Then, the radicalized source gas 7 is guided to the substrate 5, and radicals of the source gas 7 cause a chemical reaction on the substrate 5, whereby a diamond thin film 6 is formed on the substrate 5.

FIG. 8B shows the gas flow at this time. As shown in FIG. 8B, the flow G of the source gas 7 jetted from the jet port 10b is confined by the flow I of the supersonic plasma flow 11 of the carrier gas 8 on the outside. Therefore, the source gas 7 efficiently reaches the substrate 5 without diffusing outward.

When the source gas 7 collides with the substrate 5, it diffuses outward along the surface 5 a of the substrate 5 while forming a horizontal flow H in the figure. At this time, the source gas 7 collides with the flow I of the supersonic plasma flow 11 at the end J of the substrate 5. Therefore, the source gas 7 can be sufficiently excited not only at the center portion L of the substrate 5 but also at the end portion J.

As described above, according to the present embodiment, the flow G of the source gas 7 reaches the substrate 5 so as to be wrapped in the flow I of the supersonic plasma flow 11 on the outside.
Can be further prevented from spreading to the outside of the substrate (hereinafter, this is referred to as a “wrapping effect”). That is, the prevention of the diffusion increases the chance that the raw material contributes to film formation, and increases the film formation rate at which the raw material is converted into a film. When the conventional reduction / enlargement nozzle is used, the above-described wrapping effect cannot be obtained, so that the source gas 7 (radicals of the source gas 7) is reflected without adhering to the substrate 5 after colliding with the substrate 5 in many cases. There is a problem that the raw material does not contribute to film formation, but such a problem is solved according to the present embodiment. Further, since the thermal pinch effect, which is a feature of the arc jet, can be prevented, a large-area substrate 5 can be formed.

In order to obtain the above-mentioned “wrapping effect”, the position of the surface 5a of the substrate 5 is set at a height higher than the position of the virtual conical vertex F of the plug 2 as shown by the arrow Z in FIG. Desirably.

Further, according to the present embodiment, the source gas 7 is sufficiently excited not only at the center portion L of the substrate 5 but also at the end portion J, so that the radical density of each portion of the substrate 5 can be made uniform. . For this reason, the thickness of the film 6 can be made uniform in each part of the substrate 5.

Also in this embodiment, similarly to the embodiment of FIG. 7, the source gas 7 is ejected from the plug tip surface 2b downstream from the position (ejection port 10a) where the arc discharge path 12 is formed. Therefore, rapid erosion and consumption of the discharge electrode material can be prevented.

In this embodiment, the heater 14 is connected to the plug 2
Of the raw material gas 7 inside the tip cone (inside the tip cone).
(In the vicinity of the raw material gas ejection port 10b). The heater 14 converts the source gas 7 into the carrier gas 8
It is used to preheat the raw material gas 7 before being mixed into the raw material gas. If the raw material gas 7 is heated and given energy before the energy of the carrier gas 8 is applied to the raw material gas 7, the conversion efficiency of the raw material into radicals is improved, and the film formation efficiency can be further improved. The heater 14
As a result, the conical portion of the plug 2 is heated, so that the transfer of the heat of the plasma gas 7, 8 present on the plug slope 2 a to the plug 2 side can be minimized, and the decrease in the plasma activity is reduced. It can be minimized. Note that the heater 14 may be provided on the surface of the plug 2.

In the passage 21 for the source gas 7, the source gas 7
A fin may be formed to further increase the contact area with the fin.

FIG. 9 is a sectional view taken along the line AA of FIG. 8 when the passage 21 is formed as described above.

[0206] As shown in FIG.
A fin 21a is formed on 1. Therefore, passage 2
The area in which the source gas 7 passing through 1 contacts the passage 21 increases. Therefore, heat generated by the heater 14 can be efficiently transmitted to the source gas 7 via the passage 21. That is, the preheating of the raw material gas 7 can be promoted by improving the heat transfer coefficient, and the conversion efficiency from the raw material to the radical can be further improved, and the film forming efficiency can be improved.

It is also possible to implement the sixth embodiment shown in FIG. 8 and the above-described embodiments by appropriately combining them.

Although the DC power supply 9 is used in this embodiment, an AC power supply may be used instead of the DC power supply.

The above is an embodiment in which the plug nozzle 10 is an annular plug nozzle. In the above-described embodiment, when the DC power supply 9 is used, the plug 2 side is used as a cathode (cathode), and the nozzle member 3 side is used as an anode (anode). The member 3 may be used as a cathode (cathode).

Further, in the first embodiment shown in FIG. 1, the gas is converted into thermal plasma by high frequency discharge, but the gas may be converted into thermal plasma by arc discharge. Still another plasma generator may be used. For example, a high-frequency current may be applied to the induction coil to form an induction electromagnetic field, and the gas may be heated and converted into plasma by the energy of the induction electromagnetic field.

Similarly, the second embodiment shown in FIGS.
In the sixth embodiment, the gas is converted into thermal plasma by arc discharge. However, another plasma forming apparatus (high-frequency discharge, induction electromagnetic field, microwave heating, or the like) may be used.

Next, a seventh embodiment using a cluster type plug nozzle as the plug nozzle 10 will be described with reference to FIGS. 10 and 11.

FIG. 10 is an overall configuration diagram of the seventh embodiment, and shows an apparatus for vapor-phase growing a polycrystalline diamond thin film (or DLC film). FIG. 11 is a diagram illustrating the structure of a cluster plug nozzle. FIG. 11A is a longitudinal sectional view of FIG. 11B taken along the line AA.
FIG. 1B is a view of FIG.

As shown in FIG. 11, the cluster type plug nozzle 10 is a plug nozzle in which a plurality (for example, eight) of cluster nozzles 24 are annularly arranged along the outer periphery of the plug 2. The plurality of cluster nozzles 2
A small circular outlet 10a is provided for every four. The plasma forming gas is ejected from the plurality of small circular ejection ports 10a toward the plug slope 2a.

As the cluster nozzle 24, a nozzle which jets a jet having a speed higher than the speed of sound is used.

Here, the annular plug nozzle and the cluster plug nozzle will be compared.

In the annular plug nozzle shown in FIG. 1, an annular gap having a width d (for example, 0.5 mm) is formed by the outer nozzle member 3 and the inner plug 2, so that the annular jet port 10a having the width d is formed. Has formed. However, in order to obtain an accurate value d uniformly in each part in the ring direction, the plug 2 and the nozzle member 3 are required.
It is necessary to control the gap with the high precision, and extremely sophisticated processing is required. In practice, the value of the width d cannot be obtained uniformly in each part in the ring direction because of the restriction on the processing accuracy.

On the other hand, in the cluster type plug nozzle, since the ejection port 10a of the cluster nozzle 24 has a small circular shape, the diameter of the ejection port 10a of the cluster nozzle 24 is set to a value d.
It is very easy to process accurately. For this reason, in the cluster type plug nozzle, each ejection port 10a having a diameter d can be uniformly obtained without error in the ring direction around the plug 2.

Therefore, if a cluster type plug nozzle is used, the diameter d of each of the ejection ports 10a around the plug 2 becomes uniform, so that a symmetric plasma jet flow can be formed when viewed from the center of the plug 2. In other words, gas excitation by plasma is uniform, and a uniform plasma flow can be obtained. In addition, since the direction of the plasma flow is accurately determined, the supersonic plasma flow 11 can be accurately jetted to a place where surface treatment is desired. The number of cluster nozzles 24 is preferably six or more around the plug 2.

Further, since the diameter d of each ejection port 10a around the plug 2 can be accurately obtained, the sectional area A1 of the throat portion of the plug nozzle 10 can be adjusted with high accuracy. For this reason, the target performance can be obtained and the stable supersonic plasma flow 11 can be injected.

Further, since the cluster type plug nozzle 10 is an assembly of the individual cluster nozzles 24,
There is an advantage that a large area can be simultaneously formed as compared with the case where the cluster nozzle 24 is used alone.

Of course, when the cluster type plug nozzle is used, the same effect as when the annular type plug nozzle is used can be obtained. As described above, since a supersonic flow can always be obtained, a supersonic plasma flow 11 having a uniform pressure distribution can be obtained, and the distribution of the film thickness of the substrate 5 can be made uniform and the film forming speed can be improved. Can be. Further, the thermal load on the surface of the substrate 5 is also uniform, and thermal distortion of the substrate 5 is prevented.

As shown in FIG. 10, in the cluster type plug nozzle 10 of this embodiment, the source gas 7 is jetted from the tip of the plug 2 and the carrier gas 8 is injected from the cluster nozzle 24.
To make it squirt.

That is, a flat surface 2b parallel to the substrate 5 is formed at the tip of the plug 2 of the cluster type plug nozzle 10 (see FIG. 11B). A jet port 10b for the source gas 7 is formed on the flat surface 2b at the tip. The passage 21 formed along the center axis of the plug 2 communicates with the ejection port 10 b at the tip of the plug 2. Passage 2
A heater 14 for heating the raw material gas 7 passing through the passage 21 to, for example, about 2000 ° C. is provided in 1. As the heater 14, for example, a hot filament is used.

A cylindrical insulator 18 is interposed between the plug 2 and the cluster nozzle 24, and electrically disconnects the plug 2 from the cluster nozzle 24. An electrode 25 (hereinafter, referred to as a cluster electrode) is provided in the cluster nozzle 24. A DC power supply 9 is connected between the anode and the cathode by using the plug 2 as an anode and the cluster electrode 25 as a cathode.
Is applied. Therefore, the cluster nozzle 24
The arc discharge path 12 is formed between the cluster electrode 25 and the plug 2 so as to pass through the ejection port 10a of the nozzle. The cluster electrode 25 may be used as an anode and the plug 2 may be used as a cathode.

In this embodiment, the cluster nozzle 24
The arc discharge path 12 is formed between the cluster electrode 25 and the plug 2 inside, and the cluster nozzle 24 and the plug 2 are connected between the cluster nozzle 24 and the plug 2 by using one of the cluster nozzle 24 and the plug 2 as an anode and the other as a cathode. The arc discharge path 12 may be formed at the end.

The arc discharge path 12 may be formed in the cluster nozzle 24 by using one of the cluster nozzle 24 and the cluster electrode 25 as an anode and the other as a cathode.

Since the plug nozzle 10 is configured as described above, when the carrier gas 8 is supplied into the cluster nozzle 24 from the upstream of the cluster nozzle 24, the carrier gas 8 reaches the ejection port 10a. The gas 8 is heated by the discharge energy of the DC arc discharge and turned into plasma. Then, the gasified gas 8 is ejected from the ejection port 10a as a supersonic plasma jet 26. The cluster nozzle 24 may be designed as a nozzle for ejecting a sonic plasma flow.

The carrier gas 8 which is turned into plasma and excited from the ejection port 10a of the cluster nozzle 24 is
a, and expands along the conical slope 2 a of the plug 2. Then, the flow of the gas 8 intersects at one point at the virtual conical apex F of the plug 2, and thereafter becomes a uniform supersonic plasma flow 11, is guided to the substrate 5 disposed downstream of the plug nozzle 10, and collides with the substrate 5. I do.

At this time, the relationship between the flow velocity and the nozzle shape when the gas flow at the outlet of the nozzle 10 is uniform and parallel to the axis is expressed by the following equation.

[0231] However, A1 is the cross-sectional area of the throat part (cluster nozzle 2
4, Rn is the nozzle radius, M is the Mach number, and κ is the specific heat ratio of the gas.

On the other hand, the source gas 7 is supplied into the passage 21 from the upstream of the plug 2 and is jetted toward the substrate 5 from the jet port 10 b at the tip of the plug 2.

For this reason, a part of the raw material gas 7 is mixed into the carrier gas 8 which has been turned into plasma downstream of the plug 2.
That is, the source gas 7 is mixed with the supersonic plasma flow 11 of the carrier gas 8, so that the energy of the carrier gas 8 that has been turned into plasma is given to the source gas 7. Therefore, the temperature of the source gas 7 becomes high and the source gas 7 is activated. Then, the radicalized source gas 7 is guided to the substrate 5, and radicals of the source gas 7 cause a chemical reaction on the substrate 5, whereby a diamond thin film 6 is formed on the substrate 5.

The gas flow at this time is as described with reference to FIG.

That is, according to the present embodiment, the source gas 7
Flow G reaches the substrate 5 so as to be wrapped in the flow I of the supersonic plasma flow 11 on the outside, so that the diffusion of the source gas 7 to the outside of the substrate can be further prevented (wrapping effect). That is, the prevention of the diffusion increases the chance that the raw material contributes to film formation, and increases the film formation rate at which the raw material is converted into a film. Further, since the thermal pinch effect, which is a feature of the arc jet, can be prevented, a large-area substrate 5 can be formed.

In order to obtain the above-mentioned "wrapping effect", it is desirable that the substrate 5 is positioned as shown by a dashed line and is raised to a height higher than the position of the virtual conical vertex F of the plug 2.

According to the present embodiment, the source gas 7 is sufficiently excited not only at the center portion L of the substrate 5 but also at the end portion J, so that the radical density of each portion of the substrate 5 can be made uniform. . For this reason, the thickness of the film 6 can be made uniform in each part of the substrate 5.

Further, in this embodiment, since the source gas 7 is jetted from the plug tip surface 2b downstream from the position where the arc discharge path 12 is formed (the jet port 10a), the rapid discharge of the discharge electrode material takes place. Erosion and wear can be prevented.

In this embodiment, the heater 14 is provided in the passage 21 for the source gas 7. This heater 14
Is used to preheat the source gas 7 before mixing the source gas 7 into the carrier gas 8. If the raw material gas 7 is heated and given energy before the energy of the carrier gas 8 is applied to the raw material gas 7, the conversion efficiency of the raw material into radicals is improved, and the film formation efficiency can be further improved. In addition, since the conical portion of the plug 2 is heated by the heater 14, the transfer of the heat of the plasma gas 7, 8 present on the plug slope 2a to the plug 2 side can be minimized, and the plasma activity Can be minimized. The heater 14 is connected to the plug 2
May be disposed on the surface.

Although the arc discharge is generated by the DC power supply in the seventh embodiment shown in FIG. 10, the arc discharge may be generated by the AC power supply. In the seventh embodiment, the gas is converted into a thermal plasma by arc discharge.
Induction electromagnetic field, microwave heating, etc.) may be used.

Further, in the above-described first to seventh embodiments, it is desirable that the plug 2 is formed of a highly heat-resistant material.
As a result, even if the temperature becomes high at the nozzle outlet, it is possible to avoid the deformation and the erosion.

The case where the surface treatment such as film formation is performed using the plug nozzle has been described above, but the surface treatment such as film formation may be performed using the expansion deflection nozzle 40 as shown in FIG. Good.

FIG. 12 shows an eighth embodiment in which the film 6 is formed on the substrate 5 by ejecting the supersonic plasma stream 11 from the expansion / deflection nozzle 40.

The expansion deflecting nozzle 40 is connected to the inner plug 41.
And an outer nozzle member 42. A passage 43 for a plasma forming gas (carrier gas 8) is formed between the plug 41 and the nozzle member 42. The position where the interval between the plug 41 and the nozzle member 42 is minimized is the throat portion 40a of the nozzle. Throat part 40
The shape of a is the same as that of the plug nozzle 10 described above.
It is annular when viewed.

The cross-sectional area of the nozzle is gradually increased downstream of the throat section 40a, and becomes maximum at the nozzle outlet section 40c.

In this embodiment, the carrier gas 8 is supplied from the upstream to the passage 43 between the plug 41 and the nozzle member 42 as a gas for forming plasma. A passage 21 is formed along the central axis of the plug 41, and the passage 21
The raw material gas 7 is supplied from upstream. The passage 21 communicates with the ejection port 40 b at the tip of the plug 2.

The plug 41 and the nozzle member 42 are used as electrodes, respectively, and an AC voltage is applied from the RF power source 13 to these two electrodes. Therefore, the high-frequency discharge 30 is generated between the plug 41 and the nozzle member 42.

Since the expansion / deflection nozzle 40 is configured as described above, when the carrier gas 8 is supplied from upstream of the nozzle 40, the carrier gas 8 passes through the passage 43.
Then, the gas 8 is heated by the discharge energy of the high-frequency discharge 30 and turned into plasma. Then, the gas 8 converted into plasma passes through the throat portion 40a and thereafter expands while being restricted by the nozzle wall, and is ejected from the nozzle outlet 40c. In this way, a uniform supersonic plasma flow 11 is guided to the substrate 5 disposed downstream of the expansion / deflection nozzle 40 and collides with the substrate 5.

On the other hand, the source gas 7 is supplied into the passage 21 from the upstream of the plug 2 and is jetted toward the substrate 5 from the jet port 10 b at the tip of the plug 2.

For this reason, a part of the source gas 7 is mixed into the carrier gas 8 which has been turned into plasma downstream of the plug 2.
That is, the source gas 7 is mixed with the supersonic plasma flow 11 of the carrier gas 8, so that the energy of the carrier gas 8 that has been turned into plasma is given to the source gas 7. Therefore, the temperature of the source gas 7 becomes high and the source gas 7 is activated. Then, the radicalized source gas 7 is guided to the substrate 5, and radicals of the source gas 7 cause a chemical reaction on the substrate 5, whereby a diamond thin film 6 is formed on the substrate 5.

The above-described embodiments shown in FIGS. 1 to 12 may be appropriately combined with each other as long as they can be combined.

[Brief description of the drawings]

FIG. 1 is an overall configuration diagram of a first embodiment using an annular plug nozzle, FIG. 1 (a) is a longitudinal sectional view, and FIG. 1 (b) is the same as FIG. 1 (a). It is the figure seen from arrow C.

FIG. 2 is an overall configuration diagram of a second embodiment using an annular plug nozzle.

FIG. 3 is an overall configuration diagram of a third embodiment using an annular plug nozzle.

FIG. 4 is an overall configuration diagram of a fourth embodiment using an annular plug nozzle, FIG. 4 (a) is a longitudinal sectional view, and FIG. 4 (b) is that of FIG. 4 (a). 4A is a cross-sectional view, and FIG. 4C is a view of FIG.

5 (a) is a diagram showing an electric circuit for rotating an arc discharge path in a ring direction, and FIG. 5 (b) is a diagram showing a state in which the arc discharge path is rotated in a ring direction.

FIG. 6 is a diagram showing an electric circuit for forming an arc discharge path in each part in a ring direction.

FIG. 7 is an overall configuration diagram of a fifth embodiment using an annular plug nozzle.

8 is an overall configuration diagram of a sixth embodiment using an annular plug nozzle, FIG. 8 (a) is a longitudinal sectional view, and FIG. 8 (b) is a view in FIG. 8 (a). It is a figure explaining the flow of gas.

FIG. 9 is a diagram illustrating a cross-sectional shape of a gas passage.

FIG. 10 is an overall configuration diagram of a seventh embodiment using a cluster type plug nozzle.

FIG. 11 is a view for explaining the structure of a cluster type plug nozzle, and FIG. 11 (a) is a view taken on line AA of FIG. 11 (b).
11B is a sectional view, and FIG. 11B is a view of FIG.

FIG. 12 is an overall configuration diagram of an eighth embodiment using an expansion deflection nozzle.

[Explanation of symbols]

 2, 41 plug 3, 43 nozzle member 5 substrate 7 raw material gas 8 carrier gas 10 plug nozzle 10a jet port 12 arc discharge path 40 expansion deflection nozzle

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) H05H 1/34 H05H 1/34 F term (Reference) 4D075 AA01 BB45X 4G077 AA03 BA03 BA04 BE12 DB04 DB07 DB11 DB16 DB17 DB18 DB19 TA04 TA11 TG06 4K030 AA06 AA10 AA16 AA17 BA28 BA29 BB03 EA05 FA01 FA03 FA04 JA12 KA30 5F045 AA08 AA16 AB07 AC01 AC16 BB02 BB09 BB10 EC09 EF01 EF04 EF08 EF11 EH10 EH16

Claims (29)

[Claims] 1. A surface for surface-treating an object to be processed by converting the plasma-forming gas into a plasma and jetting the plasma-formed plasma-forming gas as a supersonic flow through a nozzle toward the object to be processed. In the processing apparatus, the nozzle may include: a plug having a slope formed so as to be tapered as the flow becomes downstream; and the plasma forming so that a flow is formed along the slope of the plug provided on an outer periphery of the plug. A jet nozzle for jetting a forming gas toward the plug slope, causing the plasma forming gas to be jetted from the jet port, and expanding the plasma-forming plasma gas along the slope of the plug. A surface treatment apparatus that guides a supersonic flow to the object to be processed. 2. The surface treatment apparatus according to claim 1, wherein the plasma forming gas is a gas containing a material for surface treatment. 3. The plasma-forming gas is a carrier gas, and the energy of the plasma-converted carrier gas is applied to a raw material gas serving as a raw material for surface treatment, thereby activating the raw material gas and causing the carrier gas to be activated. 2. The surface treatment apparatus according to claim 1, wherein the surface treatment apparatus guides the object to be processed. 4. The surface treatment apparatus according to claim 3, wherein a source gas jet port for jetting the source gas from the slope of the plug toward the outside of the plug is formed on the slope of the plug. 5. A raw material gas ejection port for ejecting the raw material gas from a distal end on the downstream side of the plug toward the outside of the plug is formed at a downstream distal end of the plug. 3. The surface treatment apparatus according to 3. 6. The surface according to claim 1, further comprising a heating means for heating said plug so that heat of said plasma forming gas does not move to said plug side. Processing equipment. 7. The surface treatment apparatus according to claim 3, further comprising a heating means for preheating the raw material gas before the raw material gas is mixed with the carrier gas. 8. A heating means for preheating the source gas before the source gas is mixed with the carrier gas,
The surface treatment device according to claim 4, wherein the surface treatment device is provided inside the plug. 9. The surface treatment apparatus according to claim 8, wherein a fin for increasing a contact area with the source gas is formed in a source gas passage inside the plug communicating with the source gas outlet. . 10. The surface treatment apparatus according to claim 1, wherein said plug is formed of a high heat resistant material. 11. The plug nozzle includes an outer cylindrical member and an inner plug, and has an annular gap between the outer cylindrical member and the inner plug as the discharge port. The surface treatment apparatus according to claim 1, further comprising a swirl unit configured to swirl the plasma forming gas along a ring direction of the annular ejection port. 7. 12. The plasma-forming gas is turned into plasma by arc discharge between an anode and a cathode, and the plasma-formed gas is jetted toward a workpiece as a supersonic flow through a nozzle. In the surface treatment apparatus for performing surface treatment on the object to be treated, a plug having an inclined surface formed so as to be tapered as the flow becomes downstream, and a plug provided on the outer periphery of the plug along the inclined surface of the plug And a jet nozzle for jetting the plasma forming gas toward the plug slope so that a flow is formed. The plasma forming gas is jetted from the jet port to form plasma. A surface treatment apparatus in which a supersonic flow is guided to the object by expanding a working gas along a slope of the plug. 13. The surface treatment apparatus according to claim 12, wherein one of the anode and the cathode for the arc discharge is disposed upstream of the plug, and the other pole is the plug. 14. The plug nozzle includes an outer cylindrical member and an inner plug, and has an annular gap between the outer cylindrical member and the inner plug as the discharge port. A plug plug nozzle, wherein one pole of the arc discharge anode and the cathode is the outer cylindrical member, and the other pole is the inner plug, and the outer cylindrical member and the inner plug are provided. An arc discharge path is formed in the annular discharge port between the annular discharge port and a rotating means for rotating the arc discharge path along a ring direction of the annular discharge port. The surface treatment device according to claim 12. 15. The surface according to claim 14, wherein the rotating means for rotating the arc discharge path rotates the arc discharge path by applying a perpendicular force to the arc discharge path using a magnetic force. Treatment device. 16. The rotating means for rotating the arc discharge path divides the outer cylindrical member or the inner plug into a plurality of electrodes along an annular direction of the annular ejection port, and The surface treatment apparatus according to claim 14, wherein an arc discharge path is sequentially formed along a ring direction of the ring-shaped jet port by sequentially energizing the electrodes. 17. The plug nozzle includes an outer cylindrical member and an inner plug, and has an annular gap between the outer cylindrical member and the inner plug as the discharge port. A plug plug nozzle, wherein one pole of the arc discharge anode and the cathode is the outer cylindrical member, and the other pole is the inner plug, in the ring direction of the annular jet port. The outer cylindrical member or the inner plug is divided into a plurality of electrodes along the plurality of electrodes, and the plurality of electrodes are simultaneously energized to form an arc discharge path at a plurality of locations along the annular direction of the annular outlet. 13. The method according to claim 12, wherein
The surface treatment apparatus as described in the above. 18. The plug nozzle includes an outer cylindrical member and an inner plug, and has an annular gap between the outer cylindrical member and the inner plug as the discharge port. 13. The surface treatment apparatus according to claim 12, further comprising a swirl unit configured to swirl the plasma forming gas along an annular direction of the annular ejection port. 19. The surface treatment apparatus according to claim 12, wherein said source gas is ejected from a position downstream of a portion where said arc discharge path is formed. 20. A raw material gas jet port for jetting the raw material gas from the slope of the plug to the outside of the plug,
2. The plug according to claim 1, wherein the plug is formed on a slope.
10. The surface treatment apparatus according to 9. 21. A raw material gas jet port for jetting the raw material gas from a downstream end portion of the plug toward the outside of the plug is formed at a downstream end portion of the plug. 20. The surface treatment apparatus according to 19. 22. A surface for subjecting the object to be treated by converting the plasma-forming gas into plasma and jetting the plasma-formed gas as a supersonic flow through a nozzle toward the object. In the processing apparatus, the nozzle may be configured such that a slope is formed so that the flow is tapered as the flow becomes downstream, and a flow is formed along the slope of the plug which is annularly arranged along the outer periphery of the plug. A plurality of cluster nozzles each of which ejects the plasma-forming gas toward the plug slope, and the plasma-forming gas is ejected from each of the plurality of cluster nozzles to form a plasma. By expanding the forming gas along the slope of the plug,
A surface treatment apparatus configured to guide a supersonic flow to the object. 23. A plasma forming gas ejected from each of the plurality of cluster nozzles is a carrier gas, and a raw material gas serving as a raw material for surface treatment is directed to the outside of the plug from a downstream end of the flow of the plug. Forming a raw material gas ejection port at the downstream end of the plug, and applying the energy of the plasmatized carrier gas to the raw material gas ejected from the downstream end of the plug. 23. The surface treatment apparatus according to claim 22, wherein the raw material gas is activated and guided to the object. 24. The surface according to claim 22, further comprising heating means for heating the plug so that heat of the plasma-forming gas does not move to the plug side. Processing equipment. 25. The plug according to claim 2, wherein a heating means for preheating the source gas is provided inside the plug before the source gas is mixed with the carrier gas.
3. The surface treatment apparatus according to 2. 26. The plasma forming gas is turned into plasma by arc discharge between an anode and a cathode, and one of the anode and the cathode for the arc discharge is arranged in the cluster nozzle. 23. The surface treatment apparatus according to claim 22, wherein the other pole is the plug. 27. The plasma forming gas is turned into plasma by an arc discharge between an anode and a cathode, and one of the anode and the cathode for the arc discharge is used as the cluster nozzle. 23. The surface treatment device according to claim 22, wherein the other pole is the plug. 28. The surface treatment according to claim 1, wherein the plasma forming gas is turned into plasma by arc discharge between an anode and a cathode, and an arc discharge path is formed in the cluster nozzle. apparatus. 29. A surface for processing a surface of an object to be processed by converting the gas for plasma formation into plasma and ejecting the plasma-formed gas as a supersonic flow through a nozzle toward the object to be processed. In the processing apparatus, the nozzle is an expansion deflection nozzle.