JP3529007B2 - DC plasma generator - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a direct current plasma generator for generating plasma in the vicinity of an anode based on ionization of gas, and particularly to promote a gas phase reaction of a plurality of reactive gases in a plasma state, Chemical Vapor that can form a thin film by chemically and physically depositing reactants on the surface of the object to be evaporated with the help of electric and magnetic fields
The present invention relates to a direct-current plasma generation device used for generating a reactive gas in a plasma state by a direct-current electric field applied between an anode and a cathode in a deposition method (abbreviated as CVD).

[0002]

2. Description of the Related Art A conventional DC plasma generating apparatus of this type is disclosed in, for example, Japanese Patent Laid-Open No. 6-163190 (see FIG. 4).

That is, a cylindrical anode 2 is surrounded by a cylindrical cathode 1 having a larger diameter and arranged coaxially in a closed space, and a DC voltage is applied between the anode 2 and the cathode 1. Was there.

Further, as shown in FIG. 4, a tubular cathode 1 as a hot cathode has a plurality of heat generating electrodes 1b (made of a tungsten alloy or the like) between two opposed annular electrodes 1a (made of stainless steel). ) Was used to form a tubular shape. However, in the figure, only one is shown as a representative. When a heating current is applied between the two opposed annular electrodes 1a of the tubular cathode 1 having such a structure, thermoelectrons are emitted from the surface of the heat generating electrode 1b heated to a high temperature by the heating current, and these are emitted. The reactive gas was made into a plasma state by thermionic electrons.

The reactive gas in the plasma state undergoes a gas phase reaction and is chemically and physically deposited on the surface of the object to be vapor deposited with the aid of an electric field or a magnetic field to form a thin film. Was there.

[0006]

However, in such a conventional hot cathode type direct current plasma generator, thermoelectrons become reactive every time a heating current is applied between the annular electrodes 1a of the tubular cathode 1. The heat generation electrode 1b expands due to the heat generated when the gas is brought into a plasma state or the Joule heat due to the heating current, and thermal stress is generated in the heat generation electrode 1b made of tungsten or the like which is easily broken due to expansion and contraction. As a result, structural deformation and mechanical breakage occurred in the tubular cathode 1. Further, there is a technical problem that the life of the cylindrical cathode 1 may be shortened due to such structural deformation and mechanical breakage.

With the same gist, in the conventional cold cathode type direct current plasma generator, each time a field emission voltage necessary for field emission of field emission electrons is applied from the annular electrode 1a of the cylindrical cathode 1, The heat generation electrode 1b is generated by the heat generated when the field emission electrons turn the reactive gas into a plasma state.
Expands and thermal stress is generated in the heat generating electrode 1b, and as a result, structural deformation and mechanical destruction occur in the tubular cathode 1. Further, there is a technical problem that the life of the cylindrical cathode 1 may be shortened due to such structural deformation and mechanical breakage.

An object of the present invention is to solve such a conventional technical problem, and an anode provided on a central axis and having a rotationally symmetrical shape with respect to the central axis, and a state surrounding the anode. By providing a cathode having a cylindrical spiral shape with a spiral central axis coaxial with the central axis of the anode and having a cylindrical diameter larger than the diameter of the anode, thermoelectrons turn the reactive gas into a plasma state. Even if the hot cathode type cathode expands due to the heat generated at that time or the Joule heat due to the heating current, it is possible to suppress the thermal stress from being generated in the cathode due to the spiral shape. It is a technical issue to provide a direct current plasma generation device capable of suppressing the occurrence of mechanical breakdown in the cathode. Furthermore, due to such structural deformation and mechanical breakdown, Cathode life is a technical problem to provide a direct current plasma generating apparatus can prevent the shortened.

For the same reason, even when the cold cathode type cathode expands due to the heat generated when the field emission electrons turn the reactive gas into the plasma state, thermal stress is generated in the cathode due to the spiral shape. It is a technical object to provide a direct current plasma generation device that can suppress the occurrence of structural deformation and mechanical breakdown in the cathode as a result, and further, such a structural deformation and It is a technical subject to provide a direct current plasma generation device that can prevent the life of the cathode from being shortened due to mechanical breakdown.

[0010]

According to the invention as set forth in claim 1, in the direct current plasma generating apparatus for generating plasma in the vicinity of the anode based on the ionization of gas, the central axis 1
42. A cylindrical net-like anode 14 having a rotationally symmetric shape with respect to 42, and a cylinder central axis 121 provided coaxially with the central axis 142 of the anode 14 in a state of surrounding the anode 14. Cylinder diameter 14 of reticulated reticulated anode 14
A cathode 12 having a tubular spiral shape with a tubular diameter larger than 4, and a direct current plasma generation device 10.

In other words, even when the cathode 12 expands due to the heat generated when the reactive gas is brought into the plasma state or the Joule heat due to the heating current 107, the spring elasticity due to the spiral shape causes thermal stress on the cathode 12. Can be suppressed, and as a result, structural deformation and mechanical breakdown can be suppressed from occurring in the cathode 12. Furthermore,
It is possible to prevent the life of the cathode 12 from being shortened due to such structural deformation and mechanical breakdown.

According to the second aspect of the present invention, in the direct current plasma generation apparatus for generating the plasma 102 in the vicinity of the anode based on the ionization of the gas, the wire-shaped anode 14 and the state in which the anode 14 is surrounded. And the cylindrical central axis 121 is provided coaxially with the central axis 142 of the anode 14, and the cathode 12 has a cylindrical spiral shape having a cylindrical diameter larger than the wire diameter 145 of the wire-shaped anode 14. It is a direct current plasma generation device 10 characterized by having.

That is, even when the cathode 12 expands due to the heat generated when the reactive gas is brought into the plasma state or the Joule heat due to the heating current 107, the spring elasticity due to the spiral shape causes the thermal stress on the cathode 12. Can be suppressed, and as a result, structural deformation and mechanical breakdown can be suppressed from occurring in the cathode 12. Furthermore,
It is possible to prevent the life of the cathode 12 from being shortened due to such structural deformation and mechanical breakdown.

The invention according to claim 3, that is, claim 1
Alternatively, the cylindrical spiral cathode 12 according to claim 2.
Is a linear or rod-shaped conductor that spirals according to the cylinder diameter
It is configured by being wound around
It is a plasma generation device. That is, the reactive gas is plasma-like
Generated by heat and heating current 10 7
Even if the cathode 12 expands due to
A large spring bullet is formed by forming a linear or rod-shaped conductor into a spiral shape.
Thermal stress is generated in the cathode 12 by realizing the
Can be suppressed, resulting in structural deformation and mechanical
It is possible to prevent the catastrophic breakdown from occurring in the cathode 12. Change
Due to such structural deformation and mechanical destruction.
It is possible to prevent the life of the sword 12 from being shortened.

According to the fourth aspect of the invention, the electric charge of gas is
Plasma 102 is generated near the anode based on the separation.
In a direct current plasma generator that has a cylindrical shape,
A shape surrounding the node 14 and the cylindrical anode 14
In this state, the cylindrical anode 14 is connected to the central axis 142 of
And the central axis of the spiral is provided coaxially,
Helical diameter 122 larger than cylinder diameter 146 of node 14
And a cathode 12 having a spiral shape.
It is a direct current plasma generation device 10 which is a characteristic. That is, reaction
Heat and heating current generated when a volatile gas is put into a plasma state
The cathode 12 expands due to Joule heat generated by 107
Even in the case of
It is possible to suppress the generation of thermal stress in the cathode 12,
As a result, structural deformation and mechanical breakdown occur in the cathode 12.
Can be suppressed. Furthermore, such structural variations
And shortens the life of the cathode 12 due to mechanical breakdown
Can be prevented.

According to the invention of claim 5 , claim 4
The spiral-shaped cathode 12 described in 1. is a linear or rod-shaped conductor.
The body is spirally wound according to the spiral diameter 122
A direct current plasma generation device characterized in that
It is a place.

[0017] Sokuchi, even when the cathode 12 is expanded by Joule heat due to the heat and the heating current 107 for generating a reactive gas when a plasma state to form a conductor of a linear or rod in a spiral shape By realizing large spring elasticity, it is possible to suppress the occurrence of thermal stress in the cathode 12, and as a result, it is possible to suppress structural deformation and mechanical breakdown in the cathode 12. Further, due to such structural deformation and mechanical destruction, the cathode 12
It is possible to prevent the life of the product from being shortened.

According to a sixth aspect of the present invention, the cathode 12 has a cold cathode structure.
3 or the DC plasma generator 10 according to claim 5 .

That is, in addition to the effect described in claim 3 or 5 , the cold cathode type cathode 12 expands by the heat generated when the field emission electrons 105 turn the reactive gas into the plasma state. even if, by implementing a large spring elasticity to form a linear or rod-shaped guide <br/> body in a spiral shape, it is possible to suppress the thermal stress is generated in the cathode 12, as a result, the structure It is possible to prevent the cathode 12 from being deformed or mechanically broken. Furthermore, it is possible to prevent the life of the cathode 12 from being shortened due to such structural deformation and mechanical destruction.

According to the seventh aspect of the present invention, the field emission voltage 104 required for field emission of electrons from the spiral cathode 12 is applied between the anode 14 and the cathode 12. 7. The DC plasma generator 10 according to claim 6 , wherein the plasma 10 2 is generated in the vicinity of the anode 14 based on ionization of gas by cold cathode discharge using the field emission electrons 105.

That is, similar to the effect described in claim 6 , when the cold cathode cathode 12 is expanded by the heat generated when the field emission electrons 105 turn the reactive gas into the plasma state, cathode also by implementing a large spring elasticity by forming a conductor of a linear or rod in a spiral shape, the cathode 12 can suppress the thermal stress is generated, is a result, deformation or mechanical disruption of the structural 12 can be suppressed. Furthermore, it is possible to prevent the life of the cathode 12 from being shortened due to such structural deformation and mechanical destruction.

According to the invention of claim 8 , the cathode 12 has a hot cathode structure.
3 or the DC plasma generator 10 according to claim 5 .

In other words, in addition to the effect described in claim 3 or claim 5 , the thermoelectrons of the hot cathode type are generated by the heat generated by the thermoelectrons 109 when the reactive gas is brought into a plasma state and the Joule heat by the heating current 107. even when the cathode 12 is inflated, by implementing a large spring elasticity by forming a conductor of a linear or rod in a spiral shape, it is possible to suppress the thermal stress is generated in the cathode 12, as a result, the structure It is possible to prevent the cathode 12 from being deformed or mechanically broken. Furthermore, it is possible to prevent the life of the cathode 12 from being shortened due to such structural deformation and mechanical destruction.

According to the invention of claim 9 , the heating current 10 7 necessary for emitting thermionic electrons 10 9 from the spiral cathode 12 is applied to the cathode 12, and the anode 14 and the cathode are connected. An acceleration voltage 108 for accelerating thermoelectrons 109 is applied between 12 and
9. The DC plasma generator 10 according to claim 8 , wherein plasma 102 is generated in the vicinity of the anode 14 based on ionization of gas by hot cathode discharge using the emitted thermoelectrons 109.

That is, similarly to the effect described in claim 8 , the hot cathode type cathode 12 expands by the heat generated when the thermoelectrons 109 make the reactive gas into a plasma state and the Joule heat by the heating current 107. even when, by achieving a large spring elasticity by forming a conductor of a linear or rod in a spiral shape, the cathode 12 can suppress the thermal stress is generated, as a result, Ya deformation of structural It is possible to prevent mechanical breakdown from occurring in the cathode 12. Furthermore, it is possible to prevent the life of the cathode 12 from being shortened due to such structural deformation and mechanical destruction.

[0026]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a perspective view showing a DC plasma generator 10 according to one embodiment of the present invention. FIG. 2 is a sectional view taken along the central axis 142 of the DC plasma generator 10 of FIG. FIG. 3 is a DC plasma generator 1 of FIG.
FIG. 3 is a perspective view showing a spiral shape of a cathode 12 at 0.

DC plasma generator 10 of this embodiment
Is a direct current plasma generator 10 for generating plasma 102 in the vicinity of the anode 14 based on the ionization of gas,
In particular, it promotes the gas-phase reaction of multiple reactive gases in the plasma state, and with the help of electric and magnetic fields, the reactants are chemically and physically deposited on the surface of the material to be deposited to form a thin film. In the aforementioned CVD, which can be performed, by a DC electric field applied between the anode 14 and the cathode 12,
A direct-current plasma generation device 10 used for generating a reactive gas in a plasma state, wherein heat and heating current 10 generated when the reactive gas is brought into a plasma state.
Even if the cathode 12 expands due to Joule heat due to 7, the spring elasticity due to the spiral shape suppresses the generation of thermal stress in the cathode 12, and the structural deformation and mechanical damage that are considered to be caused by the thermal stress are suppressed. It has the function of suppressing the occurrence of mechanical breakdown in the cathode 12.

As shown in FIG. 1 or 2, the anode 14 of the present embodiment is provided on the central shaft 142, and the central shaft 1
It has a cylindrical shape that is rotationally symmetric with respect to 42.

Specifically, as shown in FIG. 1, a circular ring body 2a having a diameter smaller than the spiral diameter 122 used for the cathode 12 is opposed, and a mesh 2b of conductive fibers is wound between them to form a tubular shape. What was done can be used. The material forming the anode 14 is not particularly limited, but when used for CVD, it is preferably formed of a metal having corrosion resistance to the raw material gas used.

Instead of the cylindrical anode 14,
The same function can be realized by using the wire-shaped anode 14, and the same effect due to this function can be obtained. The same function can be realized by using a rod-shaped anode 14 instead of the cylindrical anode 14.
Similar effects resulting from this function can be obtained. Here, the anode 14 having a wire shape can be realized by a wire material using a high melting point metal such as a tungsten wire (specifically, a diameter of about 0.1 mm to 2 mm). The rod-shaped anode 14 is common in material to the wire-shaped anode 14, and is a rod made of a refractory metal such as tungsten (having a diameter larger than that of the wire, specifically, several mm). To several centimeters). Instead of using the tungsten wire, it is possible to use the cathode 12 formed by evenly spreading the conductive carbon fiber (Granox XN40, Nippon Oil Co., Ltd.) into a cylindrical shape.

The cathode 12 of this embodiment is the anode 1
The central axis 142 of the above-mentioned anode 14 in a state of surrounding 4
On the other hand, a cylinder center axis 121 is provided coaxially, and has a spiral shape (see FIG. 3) having a spiral diameter 122 larger than the cylinder diameter 144 of the cylindrical anode 14 described above. Specifically, it is configured by winding two tungsten alloy wires for two turns with a phase shift of 180 degrees. The cathode 12 can be formed by winding four tungsten alloy wires in a phase of 90 degrees. As a result, a large amount of heat can be obtained, and the diameter of the electrode can be reduced.

At this time, the distance between the anode 14 and the cathode 12 can be appropriately selected so as to match the voltage applied to the discharge power source 16. Normally, the cylinder diameter 146 (or the cylinder diameter 144, It can be about 5 to 10 mm regardless of the wire diameter 145). The cathode heater power supply 18 is a power supply that supplies heating power to the cathode 12. In addition, the discharge power source 16 includes the anode 14
Is a power supply for supplying electric power for generating plasma discharge between the cathode and the cathode 12.

The cathode 12 of the spiral shape, as shown in FIG. 1, between the two opposing annular electrodes 1a, the conductor of the linear or rod-like, according to threadedly handed diameter 122 spiral (in this embodiment The spiral shape is a spiral shape, which is equivalent to a spring shape).

The spiral cathode 12 has a heating current of 10
Since the magnetic field generated by 7 is generated in the azimuth direction and the low lens force is generated in the direction of the cylinder central axis 121, the plasma 102 of the reactive gas in the plasma state near the anode 14 can be efficiently supplied to the CVD.

For example, in this embodiment, the cathode 12 is
It has a structure as shown in FIG. 1, which is formed into a cylindrical shape by using a tungsten wire having a diameter of 0.2 mm and a length of 50 mm between annular electrodes 1a of stainless steel having a diameter of 70 mm. Further, the anode 14 has a structure as shown in FIG. 1 in which a 60-mesh stainless steel wire mesh 2b is wound around a 50-mm diameter stainless steel annular body 2a, 2a so as to have a length of 50 mm.

The CVD promotes the gas phase reaction using the plasma 102 of the reactive gas supplied from the direct current plasma generator 10, and chemically assists the reactant on the surface of the object to be deposited with the help of an electric field or a magnetic field. The aforementioned CVD plasma that can be physically and physically deposited to form a thin film can be generated.

In CVD, at least 10 −6 To
A member for supporting the substrate of the anode 14 is provided at the position of the central axis 142 of the anode 14 in a closed container capable of withstanding a vacuum pressure of rr or less, and a reactive gas material for CVD film formation is further introduced. Equipped with means. It is desirable that the components constituting the CVD apparatus be made of a material having sufficient corrosion resistance against a reactive gas.

[0039] According to Sokuchi present embodiment, by realizing the large spring elasticity by forming a <br/> conductor of linear or rod into a helical shape, occurs when a reactive gas to a plasma state Even if the cathode 12 expands due to the heat generated or the Joule heat due to the heating current 107, it is possible to suppress the thermal stress from being generated in the cathode 12, and as a result, the structural deformation or It is possible to prevent mechanical breakdown from occurring in the cathode 12. Furthermore, it is possible to prevent the life of the cathode 12 from being shortened, which is considered to be caused by such structural deformation and mechanical destruction.

As the cathode structure of the cathode 12, either a cold cathode structure or a hot cathode structure can be used.

When the cathode 12 is a hot cathode, it is preferable that the cathode 12 has a high melting point heating wire. The diameter of the conductor, the number of spirals, the spiral pitch, and the like can be appropriately selected according to the capacity of the cathode 12 power supply used. The material of the heating wire can be usually tungsten, tungsten alloy, carbon or the like, but is not particularly limited.

The direct current plasma generator 10 using the cathode 12 having the cold cathode structure has a spiral cathode 12.
Field emission voltage required to emit electrons from the field 1
04 is applied between the anode 14 and the cathode 12 to generate the plasma 102 in the vicinity of the anode 14 based on the ionization of the gas by the cold cathode discharge using the field emission electrons 105. it can.

[0043] According to Sokuchi present embodiment, by realizing the large spring elasticity by forming a <br/> conductor of linear or rod in a spiral shape, in the case where the cathode 12 of the cold cathode is inflated Even if there is, it is possible to suppress the generation of thermal stress in the cathode 12 by the heat generated when the field emission electrons 105 turn the reactive gas into a plasma state, and as a result, the structure considered to be caused by the thermal stress is considered. It is possible to suppress the deformation and mechanical destruction of the cathode 12 from occurring. Furthermore, it is possible to prevent the life of the cathode 12 from being shortened, which is considered to be caused by such structural deformation and mechanical destruction.

The direct current plasma generator 10 using the cathode 12 having the hot cathode structure has a spiral cathode 12.
Heating current 1 required to emit thermoelectrons 10 9 from
07 is applied between the two opposing annular electrodes 1a, and an acceleration voltage 108 for accelerating thermoelectrons 109 is applied between the anode 14 and the cathode 12.
Plasma 102 can be generated between the anode 14 and the cathode 12 based on the ionization of gas by the hot cathode discharge using the emitted thermoelectrons 109.

For example, in the present embodiment, the inside of the container is evacuated, and then hydrogen is introduced to make it 0.06 Torr.
A current of about 20 A is applied to heat the tungsten wire to about 2500 ° C., and a positive voltage of 25 V is applied to the anode 14 with respect to the cathode 12 to generate good plasma 102 in the internal space of the anode 14. There is. Specifically, the central axis 1 by the Langmuir probe method
The plasma density of the plasma 102 generated at the position 42 was measured to be 9 of 10 per cubic centimeter.
The squared value is obtained. In addition, when the same evaluation experiment was performed in the DC plasma generation device 10 using the cathode 12 having the cold cathode structure, the central axis was obtained under the power condition of the discharge current 200 mA and the discharge voltage 500 V supplied by the discharge power supply 16. A plasma density of about 10 9 is obtained per cubic centimeter at the position of 142 (using the Langmuir probe method). Cathode heater power supply 18
Is a power supply for supplying electric power for heating the cathode 12. The discharge power supply 16 is a power supply that supplies electric power for generating plasma discharge between the anode 14 and the cathode 12.

According to [0046] Sokuchi present embodiment, by realizing the large spring elasticity by forming a <br/> conductor of linear or rod in a spiral shape, a thermionic 109 reactive gas to a plasma state Even when the hot cathode type cathode 12 expands due to the heat generated at the time of heating or the Joule heat due to the heating current 107, it is possible to suppress the generation of thermal stress in the cathode 12, and as a result, it is considered that the thermal stress is caused. It is possible to prevent the considered structural deformation and mechanical destruction from occurring in the cathode 12. Furthermore, it is possible to prevent the life of the cathode 12 from being shortened, which is considered to be caused by such structural deformation and mechanical destruction.

[0047]

According to the invention described in claim 1, 2 or 4 , in the case where the cathode 12 is expanded by the heat generated when the reactive gas is brought into the plasma state or the Joule heat by the heating current 107. Even if there is, it is possible to suppress the generation of thermal stress in the cathode 12 due to the spring elasticity due to the spiral shape, and as a result, it is possible to suppress the structural deformation and mechanical destruction of the cathode 12. Furthermore, it is possible to prevent the life of the cathode 12 from being shortened due to such structural deformation and mechanical destruction.

According to the invention of claim 3 or 5 ,
Also the cathode 12 by Joule heat due to the heat and the heating current 107 that occurs when a reactive gas to a plasma state in a case where it is inflated, realize a large spring elasticity by forming a conductor of a linear or rod in a spiral shape By doing so, it is possible to suppress the generation of thermal stress in the cathode 12, and as a result, it is possible to prevent structural deformation and mechanical destruction from occurring in the cathode 12. Furthermore, it is possible to prevent the life of the cathode 12 from being shortened due to such structural deformation and mechanical destruction.

According to the invention of claim 6 or 7 , in addition to the effect of claim 3 or 5 , the field emission electron 1
By heat 05 is generated when the reactive gas to a plasma state, even when the cathode 12 of the cold cathode is inflated, realize a large spring elasticity by forming a conductor of a linear or rod in a spiral shape By doing so, it is possible to suppress the generation of thermal stress in the cathode 12, and as a result, it is possible to prevent structural deformation and mechanical destruction from occurring in the cathode 12. Furthermore, it is possible to prevent the life of the cathode 12 from being shortened due to such structural deformation and mechanical destruction.

According to the invention of claim 8 or 9 , in addition to the effect of claim 3 or 5 , the heat or heating current generated when the thermoelectrons 10 9 turn the reactive gas into a plasma state. Even if the hot cathode type cathode 12 expands due to Joule heat generated by 107, the conductor having a linear or rod-shaped cross-section is formed in a spiral shape to realize a large spring elasticity, so that the cathode 12 is heated. It is possible to suppress the generation of stress, and as a result, it is possible to suppress the structural deformation and mechanical breakdown of the cathode 12. Furthermore, it is possible to prevent the life of the cathode 12 from being shortened due to such structural deformation and mechanical destruction.

[0051]

[Brief description of drawings]

FIG. 1 is a perspective view showing a DC plasma generation device according to an embodiment of the present invention.

FIG. 2 is a cross-sectional view taken along the central axis of the DC plasma generation device of FIG.

FIG. 3 is a perspective view showing a spiral shape of a cathode in the DC plasma generator of FIG.

FIG. 4 is a perspective view showing the shape of a cathode in a conventional DC plasma generation device.

[0053]

[Explanation of symbols]

10 DC plasma generator 102 plasma 104 Field emission voltage 105 Field emission electrons 10 7 Heating current 10 8 Accelerating voltage 10 9 thermoelectrons 12 cathode 121 Cylinder center axis 122 spiral diameter 14 Anode 142 central axis 144 cylinder diameter 145 wire diameter 146 cylinder diameter

Continuation of the front page (56) Reference JP-A-11-195498 (JP, A) JP-A-6-163190 (JP, A) JP-A-4-73896 (JP, A) JP-A-60-88955 (JP , A) JP 5-239616 (JP, A) JP 5-339733 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB name) H05H 1/24 C23C 16/50 H05H 1/46

Claims (9)

(57) [Claims] 1. A probe is formed in the vicinity of the anode based on the ionization of gas.
In a DC plasma generator that generates plasma, Cylindrical reticulated ano with a rotationally symmetric shape about the central axis
And the With the anode surrounded, the central axis of the anode
On the other hand, the central axis of the cylinder is provided coaxially, and
Has a cylindrical spiral shape with a diameter larger than the diameter of the node.
A cathode to A direct current plasma generation device comprising: 2. A probe is formed in the vicinity of the anode based on the ionization of gas.
In a DC plasma generator that generates plasma, An anode having a wire shape, With the anode surrounded, the central axis of the anode
On the other hand, the cylinder center axis is provided coaxially, and the wire shape
Cylindrical spiral with a diameter larger than the wire diameter of the anode
A cathode having a shape, A direct current plasma generation device comprising: 3. The cylindrical screw according to claim 1 or 2.
The spiral cathode has a linear or rod-shaped conductor
A special feature is that it is spirally wound according to the diameter.
DC plasma generator as a characteristic. 4. Based on the ionization of the gas, the plasma is generated near the anode.
In a direct current plasma generation device for generating plasma , an anode having a cylindrical shape and the cylindrical shape is surrounded by the cylindrical anode.
The spiral central axis is coaxial with the central axis of the anode of
Larger than the cylindrical diameter of the cylindrical shaped anode
And a cathode having a spiral shape with a spiral diameter . 5. The spiral cathode according to claim 4.
Is a linear or rod-shaped conductor that spirals according to the spiral diameter.
A direct current plasma generation device characterized in that the direct current plasma generation device is configured by being wound into a shape . 6. The cathode has a cold cathode structure.
A DC plastic according to claim 3 or 5, characterized in that
Zuma generation device. 7. An electric field for electrons from the spiral cathode.
The field emission voltage required to emit the
Apply between the cathode and the field emission electron
The annoyed gas based on the ionization of the gas due to the cold cathode discharge.
A plasma is generated in the vicinity of the magnetic field.
6. The DC plasma generator according to item 6. 8. The cathode has a hot cathode structure.
A DC plastic according to claim 3 or 5, characterized in that
Zuma generation device. 9. A thermoelectron is emitted from the spiral cathode.
Apply the heating current required for the cathode to emit
The thermoelectrons between the anode and the cathode.
Applying an accelerating voltage to accelerate the
Based on the ionization of gas by hot cathode discharge using electrons,
Characterized in that plasma is generated in the vicinity of the anode
The DC plasma generation device according to claim 8.