WO1998005803A1

WO1998005803A1 - Surface treatment apparatus, surface treatment method using the apparatus, and surface treatment nozzle used for the apparatus and method

Info

Publication number: WO1998005803A1
Application number: PCT/JP1997/002714
Authority: WO
Inventors: Shunichi Sakuragi
Original assignee: Komatsu Ltd.
Priority date: 1996-08-05
Filing date: 1997-08-05
Publication date: 1998-02-12
Also published as: JPH1050622A

Abstract

The nozzle of a suface treatment apparatus in which reactive gas is jetted against a substrate to be treated to subject the substrate to a surface treatment comprises a gas introducing section which has a sheet-like gas flow path whose length is sufficiently larger than the width and whose width direction cross section along the flow path is uniform and whose cross section gradually decreases toward the downstream, a throat section which is connected to the gas introducing section and has the minimum cross section in the whole nozzle and a gas jetting section which is connected to the throat section and whose cross section gradually increase at a predetermined widening angle. The gas made to flow through the nozzle is subjected to adiabatic expansion and accelerated to flow at a speed larger than the speed of sound and jetted out in such a way that the jetting plane of the reactive gas forms a long line.

Description

TECHNICAL FIELD Surface treatment apparatus, surface treatment method using the same, and nozzle for surface treatment used in the same

The present invention relates to a surface treatment apparatus, a surface treatment method using the same, and a surface treatment nozzle used for the same, and more particularly, to a reactive gas supply method. Background art

The gas is turned into plasma by the induction plasma method or the DC plasma jet method, and the gas is turned into a plasma. The technique of performing surface treatment such as formation or etching is already known, and is widely used for forming or etching a semiconductor thin film.

By the way, when forming a thin film using plasma, it is necessary to guide the gas, which has been converted into a plasma and has increased reactivity, to the target substrate to be processed in a short time at supersonic speed. . This is for the following reasons. If the plasma gas cannot be guided to the substrate in a short time, the excited state (active state) cannot be maintained, and the adhesion between the substrate and the reaction product is reduced, and the reaction product is generated. This is because inconveniences such as peeling of an object may occur, and a film forming rate may be reduced, thereby lowering work efficiency. Further, in the case of etching, inconveniences such as a decrease in the etching rate may occur.

In addition, since the temperature of the plasma gas is extremely high, when the gas reaches the substrate to be processed, the temperature of the gas must be lowered to a temperature that the substrate can withstand. If the temperature reaches a high temperature, not only the surface of the substrate to be processed is damaged, but also a film formation defect may occur.

Also, it is required to prevent impurities from being mixed into the plasma-formed reactive gas. This is because the inclusion of impurities causes deterioration of the film quality. It is also required to prevent impurities from being mixed into the plasma-formed reactive gas. This is because the contamination of impurities causes deterioration of the film quality.

Therefore, the present inventors have proposed a surface treatment apparatus having an improved structure which satisfies the above requirements and aims to improve the working efficiency, the film quality and the etching characteristics.

In this device, as shown in Fig. 8, a high frequency induction coil is wound around a rubber nozzle (also called a divergent nozzle). This Lapearl nozzle is connected to the gas introduction part 101 and the gas introduction part 101 which are configured so that the cross-sectional area becomes gradually smaller, and has the smallest area A 1 (diameter dl) of the whole nozzle. A throat portion (throat portion) 102 configured so as to be connected to the throat portion 102, the cross section gradually expands at a predetermined spread angle, and the maximum cross-sectional area A 2 (diameter d 2) And a gas injection pipe 103 configured to be as follows. When the reactive gas 106 is introduced from the gas introduction port 101 a at the opening end of the gas introduction section 101, the cross section of the gas introduction section 101 along the gas progresses as the gas progresses. After the gas gradually becomes smaller and stabilized in the throat section, the reactive gas accelerated by adiabatic expansion in the gas injection pipe 103 and converted into a plasma with a flow velocity larger than the sonic velocity is generated at the nozzle outlet 103 a It is configured to be sprayed to the substrate to be processed 107 provided so as to face the substrate.

Here, an induction coil 5 is wound around the outer periphery of the throat portion 102, so that a high-frequency current can be supplied to the induction coil 105. Therefore, when the induction coil 105 is energized, an induced electromagnetic field is formed in the throat portion 102, and the gas passing through the throat portion 102 is heated and plasma-excited. Then, the plasma-excited low-density plasma gas is expanded and accelerated by the expansion of the nozzle diameter of the downstream gas injection pipe 103, and becomes a supersonic plasma jet 104 from the gas injection port 103 a. It is injected.

Now, it is assumed that a high-density mixed gas 106 to be injected into the substrate to be processed 107 is supplied from the gas inlet 101 a to the rubber nozzle a. Then, as described above, an electromagnetic field is generated in the throat portion, and the energy of this field excites the gas as high-density plasma.

Then, the high-density gas that has been turned into plasma is discharged through the gas outlet pipe 103 on the downstream side. The gas is expanded and accelerated due to the spread of the chirping, and is injected from the gas injection port 103 a as a supersonic plasma jet 104 toward the substrate to be processed.

By using such a surface treatment apparatus, it is possible to improve the work efficiency, the film quality and the etching characteristics in a relatively small area. By the way, the area of solar cells and image sensors is increasing, and there is a demand to form a uniform high-quality thin film on a large-area substrate such as 1 mx 1 m.

However, the conventional nozzle as described above has a problem that it is difficult to efficiently perform thin film formation etching on a large-surface impurity substrate.

As described above, the conventional surface treatment using high-speed gas injection is performed on a small area, and it has been difficult to efficiently perform thin-film formation etching on a large-area substrate.

The present invention has been made in view of the above circumstances, and has as its object to realize uniform and highly reliable surface treatment for a large-area substrate. Disclosure of the invention

A first feature of the present invention is that in a nozzle for a surface treatment apparatus that performs a surface treatment on the substrate to be treated by injecting a reactive gas onto the surface of the substrate to be treated, the length direction is sufficiently long with respect to the width direction. A gas introduction section that is long and has the same cross section in the width direction along the flow path and has the same sheet-like flow path, and has a cross-sectional area that gradually decreases toward the downstream, and is connected to the gas introduction section. A throat portion configured to have a minimum cross-sectional area over the entire nozzle, and a gas injection portion connected to the throat portion and configured to gradually increase the cross-sectional area with a predetermined divergence angle. The gas passing through the nozzle is adiabatically expanded and accelerated from the gas injection unit into the processing chamber so as to have a flow velocity larger than the speed of sound, and the reactive gas injection surface has a long line. Form Lies in the fact that is caused to sea urchin injection.

Further, a second feature of the present invention is a surface treatment apparatus for performing a surface treatment on the substrate to be treated by injecting gas plasma onto a surface of the substrate to be treated provided in the treatment chamber; Evacuating means for evacuating to a desired pressure; Gas whose length direction is long enough to form a sheet-like channel with the same cross-section in the width direction along the flow path, and whose cross-sectional area gradually decreases toward the downstream An inlet, connected to the gas inlet, a throat configured to have a minimum cross-sectional area over the entire nozzle, and connected to the throat, gradually increasing the cross-sectional area with a predetermined divergence angle. The gas passing through the nozzle is adiabatically expanded and accelerated from the gas injection unit into the processing chamber so as to have a flow velocity higher than the sonic velocity, and the reactive gas A supersonic nozzle that forms a gas flow path so that the injection surface of the supersonic nozzle forms a long linear shape, and a part of the flow path of the supersonic nozzle excites the gas passing through the nozzle with plasma. Plasma raw Means, a gas supply unit for supplying the reactive gas to the gas introduction unit of the supersonic nozzle, and the substrate to be processed in a direction perpendicular to a longitudinal direction of a gas injection unit of the supersonic nozzle. It is provided with a transport means for transporting, and enables surface treatment of a large area.

Preferably, the plasma generating means includes a reactive gas passing through the supersonic nozzle via a pair of discharge electrodes disposed so as to face each other at both ends of a gas introduction portion or a throat portion of the supersonic nozzle. The configuration is such that high-frequency power is applied to the gas.

Preferably, the plasma generating means is disposed on an outer wall along a longitudinal direction of a gas introduction portion or a throat portion of the supersonic nozzle so as to face each other.

A high frequency power is applied to a reactive gas passing through the supersonic nozzle via a pair of discharge electrodes.

Preferably, the plasma generating means is disposed on an inner wall along a longitudinal direction of a gas introduction portion or a throat portion of the supersonic nozzle so as to face each other.

More desirably, the plasma generating means includes a pair of mesh-shaped members arranged in the gas introduction portion or the throat portion of the supersonic nozzle along the longitudinal direction so as to face each other at right angles to the gas flow. It is configured to apply high-frequency power to a reactive gas passing through the supersonic nozzle via a discharge electrode. In a third method of the present invention, there is provided a vacuum evacuation step of evacuating the processing chamber to a desired pressure, an injection port being provided in the processing chamber, a length direction being sufficiently longer than a width direction, and extending along a flow path. The cross section in the width direction constitutes the same sheet-like flow path, and is connected to the gas introduction section, which is configured so that the cross-sectional area gradually decreases as going downstream. A throat portion configured to have a minimum cross-sectional area over the entire nozzle, and a gas injection portion connected to the throat portion and configured to gradually expand the cross-sectional area with a predetermined spread angle. The gas passing through the nozzle is thermally inflated and accelerated from the gas injection unit so that the flow velocity is larger than the sonic velocity in the processing chamber, so that the reactive gas injection surface has a long linear shape. So that it can be injected into A gas supply step of supplying a reactive gas from a gas supply port of a supersonic nozzle forming a flow path, and an electric field is formed in the flow path of the nozzle, and the gas is plasma-excited. Generating a gas plasma, adiabatically expanding the gas plasma to accelerate the gas plasma in a desired direction so as to have a flow velocity larger than the sonic velocity, and moving the substrate to be processed in the longitudinal direction of the supersonic nozzle in the vicinity of the injection port. An object of the present invention is to conduct a two-dimensional surface treatment on the surface of the substrate to be processed by introducing high-speed gas plasma to the surface of the gas to be processed while transporting the substrate vertically.

In the apparatus and method of the present invention, strictly, "insulated" state cannot be created, but the term "insulated" is used to mean a state in which heat flow is extremely small.

In addition, this supersonic nozzle is configured so that the cross-sectional area is gradually increased at the gas injection part, and the maximum cross-sectional area is formed at the outlet in the gas injection part. No need to take.

As described above, according to the present invention, a long nozzle can be configured to form a two-dimensionally uniform curtain-shaped supersonic airflow. By scanning this, it is possible to perform two-dimensionally uniform surface treatment with good workability.

In addition, the present invention can be applied not only to plasma surface treatment using a supersonic nozzle, but also to general surface treatment in which a high-speed gas flow is applied to perform surface treatment. BRIEF DESCRIPTION OF THE FIGURES FIG. 1 is a diagram showing a surface treatment apparatus of a first embodiment of the present invention,

FIG. 2 is a diagram showing a surface treatment apparatus of a second embodiment of the present invention,

FIG. 3 is a diagram showing a surface treatment apparatus of a third embodiment of the present invention,

FIG. 4 is a diagram showing a surface treatment apparatus of a fourth embodiment of the present invention,

FIG. 5 is a diagram showing a surface treatment apparatus of a fifth embodiment of the present invention,

FIG. 6 is a view showing a surface treatment apparatus of a sixth embodiment of the present invention,

FIG. 7 is a diagram showing a gas supply pipe of the surface treatment apparatus,

FIG. 8 is a diagram showing a conventional surface treatment apparatus. BEST MODE FOR CARRYING OUT THE INVENTION

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

As shown in FIG. 1, the surface treatment apparatus according to the embodiment of the present invention is formed of a gas formed so that the length direction is sufficiently long with respect to the width direction and the cross-sectional area is gradually reduced. Connected to the introduction section 1 and the gas introduction section 1, has a minimum cross-sectional area over the entire nozzle, and extends along the substrate to be processed in the same cross-sectional shape in a direction orthogonal to the moving direction of the substrate to be processed A throat portion 2 configured as described above, and a gas injection portion 3 connected to the throat portion 2. A supersonic nozzle, a pair of discharge electrodes 5a, 5b disposed so as to face each other at both ends of the gas introduction section 1, and a reactive gas passing through the gas introduction section through these, High-frequency power supply 6 that applies voltage and excites plasma The gas passing through the nozzle is adiabatically expanded, accelerated from the gas injection unit 3 so as to have a flow velocity larger than the sonic velocity in the processing chamber, and the reactive gas injection surface has a slightly wider width. The target substrate 7 is conveyed perpendicularly to the longitudinal direction of the gas injection part of the supersonic nozzle by the conveyer roller 8 so that the substrate 7 is conveyed in a two-dimensional direction. This is to form a uniform thin film.

With such a configuration, the reactive gas introduced into the gas introduction unit is excited by receiving the energy of the electric field generated by the high-frequency voltage to become gas plasma, and the gas plasma passes through the throat unit. The flow velocity along the substrate to be processed In the same direction. Thereafter, the gas plasma uniformed in the longitudinal direction is adiabatically expanded due to the shape of the gas injection unit, and is injected in a long linear shape having a width slightly on the surface of the substrate to be processed.

Although not shown, at least the nozzle orifice 3a of the nozzle is disposed in a chamber that can be evacuated, and this chamber is desirably provided by a vacuum pump composed of a mechanical booster pump and a single pump. is evacuated so that the pressure P c _h. The substrate to be processed is maintained at a desired temperature by a heater (not shown).

Further, in this device, the nozzle is operated under the following conditions so that the reactive gas passing through the nozzle is adiabatically expanded and injected from the injection port 3a of the nozzle at a flow velocity u greater than the sonic velocity a. Construct a sonic nozzle.

This nozzle is a nozzle fine in cross-section, reactivity gas 6 to be injected on the surface of the processed substrate 7 (e.g. Rei_11 ₄ and 1 ^ mixed gas of ₂₎ gas inlet portion 1 (the width of the cross-section w: 5 O mm) and a throat section with a minimum cross-sectional area A 1 (width dl: 16 mm) across the nozzle, with a gas inlet 1 configured so that the cross-sectional area gradually decreases as the gas progresses (Throat part) 2 and gas injection where plasma area 4 gradually injects from gas injection port 3 a having maximum cross-sectional area A 2 (width d 2: 40 mm) with a predetermined spread angle Section 5 Then, the substrate to be processed 7 is continuously moved by the transport roller 8 so as to face the linear plasma flow 4 ejected from the ejection port 3a of the nozzle.

A pair of discharge electrodes 5a and 5b are provided as plasma generating means on the outer walls at both ends of the gas introduction section 1. High-frequency currents (500 W, 13 When 56 MHz is applied, an induced electromagnetic field is formed in the outlet 3 and the gas passing through the throat 2 is plasma-excited.

The high-density gas, which has been turned into plasma, is expanded and accelerated due to the expansion of the nozzle by the gas injection unit 3 on the downstream side, and is injected as a supersonic curtain-like plasma flow 4 from the gas injection port 3a. You.

Here, if the cross-sectional divergence angle before and after the throat portion 2 is too large, separation of the boundary layer occurs on the wall surface. Therefore, it is necessary to set an appropriate size, for example, about 15 °. In the slot 2, the high-density reactive gas, which has been turned into plasma, is excited by the heat into a highly reactive state, that is, a state in which the reactive gas easily reacts on the substrate to be processed. From the experimental results for a two-dimensional long nozzle, the same effects as those of a conventional rubber nozzle can be obtained for a three-dimensional cross section. It can be seen that the result almost coincides with the calculation result.

By the way, since the temperature of this reactive gas is very high, and in some cases reaches as high as 10,000 degrees, when the reactive gas is injected onto the substrate to be processed, the substrate itself withstands this temperature. May not be possible.

However, since the reactive gas passing through the inside is designed to be adiabatically expanded, it is rapidly cooled during this adiabatic expansion process and has an appropriate temperature that does not cause deterioration of the substrate before reaching the surface of the substrate to be processed. become. Since the temperature at this time is determined by the divergence ratio A 2 ZA 1, an arbitrary temperature can be obtained depending on the nozzle design conditions.

According to the theory of one-dimensional fluid dynamics, the relationship between the substrate temperature and the flow velocity in the adiabatic flow of a complete gas is expressed by the following equation.

T. = T + (1/2) · {(7-1) / (r · R)} · (u) ^2- (1)

Τ ₀ / Τ = 1 + ((γ-l) / 2) · (Μ) ^2- (2)

here,

Τ ₀ : Total temperature of the flow (approximately equal to the temperature of the throat 3 which is the heating part) T: Static temperature of the flow (so-called temperature)

: Specific heat ratio of gas

R: gas constant

u: Flow velocity

M: Mach number

It is.

Equation (2) is obtained by rewriting equation (1) using Mach numbers (u / a, a: sound velocity). The Mach number M is uniquely determined as a function of the Suehiro ratio AsZA. From the above equation (1), the total temperature T in the adiabatic expansion process. Since the value of is kept constant, it can be seen that the static temperature T decreases as the flow velocity u increases. In other words, the higher the flow speed, the more rapid the temperature drops.

Furthermore, according to the surface treatment method using the surface treatment device of the present invention, a high-density and highly reactive gas can be reduced to an arbitrary temperature and guided onto the substrate 7 to be treated. As a result, a uniform film can be formed over a large area, and not only the working efficiency but also the film quality can be greatly improved.

In this embodiment, the film formation is described, but the present invention is also applicable to etching and the like. In the above-described embodiment, the substrate is transported. However, the substrate may be transported at a desired speed on the nozzle side.

Further, in this embodiment, the discharge electrodes for plasma excitation are provided at both ends of the gas introduction part, but the present invention is not limited to this and can be changed as appropriate.

Next, a second embodiment of the present invention will be described.

As shown in FIG. 2, this surface treatment apparatus is characterized in that the discharge electrodes 15a and 15b are formed in a mesh shape and arranged so as to be orthogonal to the gas flow of the nozzle 內. . The other parts are formed in exactly the same manner as in the first embodiment. In this case, since the gas flow comes into direct contact with the discharge electrode, it is necessary to use an electrode material that is difficult to react with the reactive gas.

Further, as a third embodiment of the present invention, as shown in FIG. 3, the discharge electrodes 25a and 25b are arranged along the inner wall of the gas inlet 1 of the nozzle. Things. The other parts are formed in exactly the same manner as in the first embodiment. Also in this case, since the gas flow comes into direct contact with the discharge electrode, it is necessary to use an electrode material that does not easily react with the reactive gas.

As shown in FIG. 4 as a fourth embodiment of the present invention, discharge electrodes 35a and 35b are arranged along the outer wall of the gas introduction portion 1 of the nozzle, and the nozzle is heated by induction heating. The gas passing through the inside may be excited by plasma.

Further, as a fifth embodiment of the present invention, as shown in FIG. 5, discharge electrodes 45a and 45b are arranged along the inner wall of the throat portion 2 of the horn, and a high frequency power supply 6 A voltage may be applied to excite the gas passing through the nozzle into plasma. Les ,.

Further, as a sixth embodiment of the present invention, as shown in FIG. 6, a reactive gas supplied here from a gas supply pipe 11 penetrating through a gas introduction portion 1 of a nozzle is used as plasma excitation means, Excitation may be performed by the microwave 12 that has passed through the waveguide 55. Other parts are formed in the same manner as in the above embodiment. As shown in FIG. 7, the gas supply pipe 11 is configured to be blown in a direction perpendicular to the pipe from holes provided at equal intervals in a part of the pipe.

Although the Laval nozzle has been described in the above embodiment, it goes without saying that a nozzle having another structure may be used.

In addition, in the above-described embodiment, the film forming method has been described. However, it is needless to say that the present invention is not limited to the film forming and can be applied to the etching.

In each of the above-described embodiments, the injection nozzle is fixed and the substrate to be processed is transported. However, in the present invention, the substrate to be processed may be fixed and the injection nozzle may be moved. .

In addition, as described above, the gas plasma injected from the gas introduction unit preferably has a flow velocity equal to or higher than the sonic velocity, but the effect of the present invention can be obtained if the velocity is equal to or close to the sonic velocity. .

Further, in the above-described embodiment, the example in which the vacuum exhaust means is provided has been described. However, in the present invention, there is no requirement for the condition of reduced pressure, and the same effect can be obtained even under normal pressure. it can. Industrial applicability

As described above, according to the present invention, it is possible to efficiently form and etch a thin film uniformly and quickly over a large area.

Claims

The scope of the claims

(1) an injection nozzle that converts a reactive gas into a plasma flow and injects the same,

Gas supply means for supplying the reactive gas to the injection nozzle,

Conveying means for moving a substrate to be surface-treated by the plasma flow jetted by the jet nozzle relative to the jet nozzle;

With

The injection nozzle,

A gas introduction unit into which the reactive gas supplied by the gas supply unit is introduced; and a throat connected to the gas introduction unit and extending along the substrate to be processed in a direction orthogonal to a moving direction of the substrate to be processed. Department and

A gas injection unit connected to the throat unit and having an inverted funnel shape in cross section; and a plasma generation unit provided in the gas introduction unit and generating a plasma flow by exciting the reactive gas.

With

The plasma flow generated by the plasma generation means is made to pass through the throat portion to make the flow velocity uniform in a direction along the substrate to be processed, and the plasma flow is adiabatically expanded by the gas injection portion. A surface treatment apparatus for accelerating by means of spraying on the substrate to be treated.

(2) The plasma flow injected from the injection nozzle is:

2. The surface treatment device according to claim 1, wherein the surface treatment device is accelerated to a flow velocity higher than a sonic velocity.

(3) The plasma generating means includes:

A pair of discharge electrodes disposed to face the gas introduction unit;

The surface treatment apparatus according to claim 1, further comprising:

(4) The pair of electrodes,

2. The surface treatment apparatus according to claim 1, wherein the surface treatment apparatus is disposed orthogonal to a direction in which the reactive gas flows, and has a plurality of holes for allowing the reactive gas to pass therethrough.

(5) The plasma generation means,

Microwave irradiation means for irradiating the gas inlet with a microphone mouth wave

The surface treatment apparatus according to claim 1, further comprising:

(6) an injection nozzle that converts a reactive gas into a plasma flow and injects the same, a gas supply unit that supplies the reactive gas to the injection nozzle,

With

The injection nozzle,

A gas introduction unit into which the reactive gas supplied by the gas supply unit is introduced; and a slot connected to the gas introduction unit and extending along the substrate to be processed in a direction orthogonal to a moving direction of the substrate to be processed. One part,

A gas emitting portion connected to the throat portion and having an inverted funnel shape in cross section; and a plasma generating means provided on the throat and generating a plasma flow by exciting the reactive gas.

With

The reactive gas introduced into the gas introduction unit is caused to pass through the throat unit to make the flow velocity uniform in a direction along the substrate to be processed, and to generate a plasma flow by the plasma generation unit, A surface treatment apparatus that accelerates the plasma flow by adiabatically expanding the gas flow at the gas injection unit and jets the plasma flow to the substrate to be processed.

(7) The plasma flow injected from the injection nozzle is:

7. The surface treatment device according to claim 6, wherein the surface treatment device is accelerated to a flow velocity higher than the speed of sound.

(8) The plasma generating means,

A pair of discharge electrodes disposed to face the throat portion

7. The surface treatment apparatus according to claim 6, comprising:

(9) Exciting the reactive gas to generate a plasma flow of the reactive gas, extending the plasma flow along the substrate to be processed, and forming a throat portion having a predetermined length along the plasma flow. By passing the fluid, the flow velocity is made uniform in the direction along the substrate to be treated,

The plasma stream is further adiabatically expanded and accelerated and sprayed on the substrate to be processed, A surface treatment method for performing a surface treatment on the substrate to be treated.

(10) The surface treatment method according to claim 9, wherein the surface treatment is performed under reduced pressure.

(11) Introduce reactive gas,

Passing the reactive gas through a throat portion extending along the substrate to be treated and having a predetermined length;

Exciting the reactive gas in the throat portion to convert the reactive gas into a plasma flow and uniformizing the flow velocity in a direction along the substrate to be processed,

The plasma stream is further adiabatically expanded to accelerate and spray the substrate to be processed,

A surface treatment method for performing a surface treatment on the substrate to be treated.

(12) The surface treatment method according to claim 11, wherein the surface treatment is performed under reduced pressure.

(13) a gas introduction part into which a reactive gas is introduced,

A throat portion connected to the gas introduction portion, and extending along a substrate to be treated, the surface treatment of which is performed by the reactive gas;

A gas injection unit connected to the throat unit and having an inverted funnel shape in cross section, a plasma generation unit provided in the gas introduction degree unit, and generating a plasma flow by exciting the reactive gas;

With

The plasma flow generated by the plasma generation means is made to pass through the throat portion to make the flow velocity uniform in a direction along the substrate to be processed, and the plasma flow is adiabatically expanded by the gas injection portion. Nozzle for surface treatment equipment that accelerates and jets by

(1) a gas introduction part into which a reactive gas is introduced,

A gas injection unit connected to the throat unit and having an inverted cross section, and a plasma generation unit provided in the throat unit and generating a plasma flow by exciting the reactive gas.

With The reactive gas introduced into the gas introduction part is converted into a plasma flow by the plasma generation means by passing through the throat part, and the flow velocity of the plasma flow is made uniform in a direction along the substrate to be processed. Further, a nozzle for a surface treatment apparatus which accelerates and jets the plasma stream by adiabatically expanding the gas jet section.