Plasma blow lamp

Abstract

The invention discloses a plasma blast burner, and relates to the technical field of radio frequency plasmas, the plasma blast burner comprises a blast burner main body and at least one radio frequency induction coil, the radio frequency induction coil surrounds the blast burner main body, the radio frequency induction coil comprises at least one coil section with the inner diameter gradually changing, and when a plurality of coil sections are arranged, the plurality of coil sections are connected in sequence; in the position, corresponding to the radio frequency induction coil, in the blow lamp body, the plasma excitation gas linearly moves towards a blow lamp opening of the blow lamp body; due to the arrangement of the coil sections with the gradually-changed inner diameters in the radio frequency induction coil, formed magnetic induction lines are not completely parallel to the axial direction of the blowtorch, so that plasma excitation gas does linear motion towards the blowtorch opening of the blowtorch main body, magnetic lines of force can be cut to generate induced electromotive force, and gas ionization is promoted to form high-temperature plasma; therefore, airflow output by the whole blowtorch body is closer to a laminar flow state, so that the deposition efficiency is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of radio frequency plasma, in particular to a plasma torch. Background Art

[0002] Radio frequency (RF) plasma is a technology that uses a high-frequency alternating electromagnetic field to ionize gas to form a stable plasma. Compared with traditional DC arc plasma, RF plasma has the following significant advantages: it uses an electrodeless discharge mode to avoid direct contact between electrodes and plasma; it has higher system stability; and it can operate under low gas pressure conditions. These characteristics give it broader application prospects in semiconductor manufacturing, thin film deposition and other fields.

[0003] The basic structure of a commonly used radio frequency plasma torch includes a torch body and an induction coil. The induction coil is cylindrical and surrounds the outside of the torch body. The magnetic induction lines generated by the induction coil are parallel to the torch axis. According to the principle of plasma excitation, the working gas needs to cut the magnetic lines of force to effectively excite the plasma. Therefore, the gas usually needs to enter the torch at a specific angle (generally along the tangent direction of the outer circle of the torch) and form a spiral airflow to fully contact the magnetic lines of force. However, in deposition applications, this spiral airflow pattern is inconsistent with the ideal laminar output state, resulting in low raw material deposition efficiency and limiting its large-scale industrial application.

[0004] Therefore people are in urgent need of a plasma torch with high deposition efficiency. Summary of the Invention

[0005] The purpose of the present invention is to provide a plasma burner to solve the problems existing in the above-mentioned prior art. Through the design of the radio frequency induction coil, the plasma-excited gas can move linearly toward the burner nozzle of the burner body to cut the magnetic lines of force, making the airflow output by the burner closer to a laminar state, thereby improving the deposition efficiency.

[0006] To achieve the above-mentioned objectives, the present invention provides the following solution: The present invention provides a plasma burner, comprising a burner body and at least one radio frequency induction coil, wherein the radio frequency induction coil surrounds the outside of the burner body and includes at least one coil segment with a gradually changing inner diameter. When a plurality of such coil segments are provided, the plurality of such coil segments are connected in sequence. At a position within the burner body corresponding to the radio frequency induction coil, plasma excitation gas moves linearly toward the burner port of the burner body.

[0007] Preferably, the blowtorch body includes a plasma excitation gas channel, a process gas channel and a raw gas channel, the process gas channel and the raw gas channel are connected to the plasma excitation gas channel, the radio frequency induction coil surrounds the outside of the plasma excitation gas channel, and the outlet of the plasma excitation gas channel is the blowtorch mouth.

[0008] Preferably, the raw gas channel, the process gas channel and the plasma excitation gas channel are arranged in sequence from the inside to the outside, the outlets of the raw gas channel and the process gas channel are spaced from the outlet of the plasma excitation gas channel to form a flow space, and the RF induction coil is arranged corresponding to the flow space.

[0009] Preferably, the shell of the raw gas channel, the shell of the process gas channel, and the shell of the plasma excitation gas channel are all cylindrical structures.

[0010] Preferably, the inlet end of the process gas channel extends out of the plasma excitation gas channel, and the raw material gas channel extends out of the process gas channel.

[0011] Preferably, an acceleration section for accelerating the flow rate is provided at the outlet of the process gas channel.

[0012] Preferably, the outlet end of the raw material gas channel is configured to be constricted.

[0013] Preferably, the first gas inlet of the plasma excitation gas channel, the second gas inlet of the process gas channel, and the third gas inlet of the raw material gas channel are all located at one end of the channel away from the burner port.

[0014] Preferably, the radio frequency induction coil is hollow to form a passage for circulating cooling water.

[0015] Preferably, the material of the blowtorch body is quartz.

[0016] Compared with the prior art, the present invention mainly achieves the following technical effects:

[0017] The arrangement of coil segments with gradually changing inner diameters in the RF induction coil ensures that the magnetic induction lines formed are not completely parallel to the burner axis. Therefore, the linear motion of the plasma-excited gas toward the burner nozzle of the burner body can also cut the magnetic lines of force to generate an induced electromotive force, prompting the gas to ionize and form a high-temperature plasma. In this way, the airflow output by the entire burner body is closer to a laminar state, thereby improving deposition efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0019] Figure 1 This is a front view of a plasma torch according to an embodiment of the present invention;

[0020] Figure 2 is a cross-sectional view of a plasma torch according to an embodiment of the present invention;

[0021] Figure 3 A top view of a plasma torch according to an embodiment of the present invention;

[0022] Among them, 1. Blowtorch body; 2. RF induction main coil; 3. First air inlet; 4. Third air inlet; 5. Second air inlet; 6. Plasma excitation gas channel; 7. Raw material gas channel; 8. Process gas channel. DETAILED DESCRIPTION

[0023] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0024] The purpose of the present invention is to provide a plasma burner to solve the problems existing in the prior art. Through the design of the radio frequency induction coil, the plasma-excited gas can move linearly toward the burner nozzle of the burner body to cut the magnetic lines of force, making the airflow output by the burner closer to a laminar state, thereby improving the deposition efficiency.

[0025] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0026] Please refer to Figures 1 to 3 As shown, a plasma burner is provided, comprising a burner body 1 and at least one radio frequency induction coil 2. When multiple radio frequency magnetic induction coils are provided, the multiple radio frequency magnetic induction coils are arranged in sequence along the output direction of the burner body 1, and the radio frequency induction coil 2 surrounds the outside of the burner body 1. The radio frequency induction coil 2 includes at least one coil segment with a gradually changing inner diameter. When multiple coil segments are provided, the multiple coil segments are connected in sequence. At the position of the burner body 1 corresponding to the radio frequency induction coil 2, the plasma excitation gas moves linearly toward the burner port of the burner body 1.

[0027] When the RF induction coil 2 includes one coil segment, the small diameter end of the entire RF induction coil 2 is arranged toward or away from the output port of the blowtorch body 1. The RF induction coil 2 can be a frustum-shaped structure with a straight outer edge, or it can be an irregular structure with an arc outer edge. When the RF induction coil 2 includes multiple coil segments, the small diameter ends of two adjacent coil segments are connected, or among two adjacent coil segments, the small diameter end of one coil segment is connected to the large diameter end of the other coil segment.

[0028] The working principle of this device is as follows: the RF induction coil 2 is connected to a high-performance RF induction power supply through a high-frequency cable. When the RF power supply is started, a strong high-frequency current surges rapidly in the RF induction coil 2, exciting and generating a strong induced magnetic field. Due to the particularity of the gradual change in the inner diameter of the coil segment, the spatial position and electromagnetic environment of each turn of the RF induction coil 2 are different, resulting in different magnetic field intensities generated by each turn. This uneven magnetic field distribution makes the formed magnetic induction lines not completely parallel to the axial direction of the blowtorch body 1 (i.e., the direction of gas flow), but forms a specific angle with the axial direction of the blowtorch body 1. When the plasma-excited gas flows from the inside of the blowtorch body 1 to the blowtorch outlet in a straight line, it will interact with these inclined magnetic induction lines, cutting the magnetic lines of force to generate an induced electromotive force, thereby promoting the ionization of the plasma-excited gas to form a high-temperature plasma. The airflow output by the entire blowtorch body 1 is closer to a laminar flow state, thereby improving the deposition efficiency.

[0029] The blowtorch body 1 includes a plasma excitation gas channel 6, a process gas channel 8 and a raw material gas channel 7. The process gas channel 8 and the raw material gas channel 7 are connected to the plasma excitation gas channel 6. The radio frequency induction coil 2 surrounds the outside of the plasma excitation gas channel 6. The outlet of the plasma excitation gas channel 6 is the blowtorch mouth. The plasma excitation gas, process gas and raw material gas can be selected according to needs. The plasma excitation gas can be an inert gas such as argon, nitrogen and helium.

[0030] In this embodiment, the raw gas channel 7, the process gas channel 8 and the plasma excitation gas channel 6 are arranged in sequence from the inside to the outside. The outlets of the raw gas channel 7 and the process gas channel 8 are spaced apart from the outlet of the plasma excitation gas channel 6 to form a flow space. The RF induction coil 2 is arranged corresponding to the flow space. The plasma gas cuts the magnetic lines in the flow space to ionize and form a high-temperature plasma.

[0031] A plurality of process gas channels 8 can be provided, and the plurality of process gas channels 8 can be nested in sequence.

[0032] In this embodiment, the shell of the raw gas channel 7, the shell of the process gas channel 8 and the shell of the plasma excitation gas channel 6 are all cylindrical structures. In other embodiments, the three can also be designed as cylindrical structures with other cross-sectional shapes.

[0033] Due to the existence of the flow space, the inlet end of the process gas channel 8 is extended with the plasma excitation gas channel 6, and the raw material gas channel 7 is extended with the process gas channel 8. The extension method can extend the length of the channel to ensure the stability of the gas flow, thereby improving the final deposition efficiency.

[0034] An acceleration section for accelerating the flow rate is provided at the outlet of the process gas channel 8. The acceleration section can be a necking structure, or the overall cross-sectional area of ​​the process gas channel 8 can be directly reduced, so that the entire process gas channel 8 exists as an acceleration section; the high-speed flow of process gas at the outlet of the process gas channel 8 can not only efficiently carry the generated plasma out of the blowtorch body 1 to form a stable and powerful plasma torch, but also utilize the flushing effect generated by the gas flow to effectively reduce the accumulation of reactants at the outlet of the raw gas channel 7, avoid the occurrence of blockage, and ensure the continuous and stable operation of the equipment.

[0035] In this embodiment, the outlet end of the raw gas channel 7 is narrowed to increase the flow rate of the raw gas, shorten the reaction time of the raw gas at the outlet of the raw gas channel 7, and further reduce the accumulation of reactants at the outlet of the raw gas channel 7.

[0036] The first air inlet 3 of the plasma excitation gas channel 6, the second air inlet 5 of the process gas channel 8 and the third air inlet 4 of the raw material gas channel 7 are all located at the end of the channel away from the blowtorch mouth to extend the gas flow path and ensure that the gas has a stable flow state when entering the flow space, thereby improving the deposition effect.

[0037] The RF induction coil 2 is hollow to form a passage for circulating cooling water. By passing cooling water into the passage, the temperature of the RF induction coil 2 can be reduced, ensuring that the device operates in a safe, stable and efficient state.

[0038] In this embodiment, the material of each component of the blowtorch body 1 is quartz. If the budget is sufficient, high-purity quartz can be selected.

[0039] In the plasma excitation gas channel 6 , a cylindrical cooling layer or other gas layers may be provided as needed.

[0040] During actual use, the plasma excitation gas enters the plasma excitation gas channel 6, cuts the magnetic lines of force to generate high-temperature plasma, and creates a high-temperature environment; the process gas can carry the generated plasma out of the blowtorch to form a stable and powerful plasma torch; the raw material gas enters the high-temperature environment and undergoes a violent thermochemical reaction. The raw material molecules are rapidly decomposed and recombined under the dual effects of high temperature and plasma, and finally generate target reactants, which are evenly deposited on the target material surface under the promotion of the gas flow field, completing the key process of material surface treatment or precision machining.

[0041] Adaptive changes based on actual needs are all within the scope of protection of the present invention.

[0042] It should be noted that it will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the present invention can be implemented in other specific forms without departing from the spirit or essential characteristics of the present invention. Therefore, the embodiments should be considered in all respects as illustrative and non-restrictive, and the scope of the present invention is defined by the appended claims, not the foregoing description, and it is intended that all variations within the meaning and range of equivalents of the claims be encompassed within the present invention. Any reference signs in the claims should not be construed as limiting the claim to which they relate.

[0043] The present invention uses specific examples to illustrate the principles and implementation methods of the present invention. The above examples are only intended to help understand the method and core concept of the present invention. At the same time, those skilled in the art will find that the specific implementation methods and application scopes may vary based on the concept of the present invention. In summary, the contents of this specification should not be construed as limiting the present invention.

Claims

1. A plasma torch, characterized in that: The device comprises a blowtorch body and at least one radio frequency induction coil, wherein the radio frequency induction coil surrounds the outside of the blowtorch body and comprises at least one coil segment with a gradually changing inner diameter. When a plurality of the coil segments are provided, the plurality of coil segments are connected in sequence. At a position in the blowtorch body corresponding to the radio frequency induction coil, the plasma excitation gas moves linearly toward the blowtorch port of the blowtorch body.

2. The plasma torch according to claim 1, wherein: The blowtorch body includes a plasma excitation gas channel, a process gas channel and a raw gas channel. The process gas channel and the raw gas channel are connected to the plasma excitation gas channel. The radio frequency induction coil surrounds the outside of the plasma excitation gas channel. The outlet of the plasma excitation gas channel is the blowtorch mouth.

3. The plasma torch according to claim 2, wherein: The raw gas channel, the process gas channel and the plasma excitation gas channel are arranged in sequence from the inside to the outside, the outlets of the raw gas channel and the process gas channel are spaced from the outlet of the plasma excitation gas channel to form a flow space, and the RF induction coil is arranged corresponding to the flow space.

4. The plasma torch according to claim 3, wherein: The shell of the raw gas channel, the shell of the process gas channel, and the shell of the plasma excitation gas channel are all cylindrical structures.

5. The plasma torch according to claim 3, wherein: The inlet end of the process gas channel extends out of the plasma excitation gas channel, and the raw material gas channel extends out of the process gas channel.

6. The plasma torch according to claim 3, wherein: An acceleration section for accelerating the flow rate is provided at the outlet of the process gas channel.

7. The plasma torch according to claim 2, characterized in that The outlet end of the raw material gas channel is configured to be constricted.

8. The plasma torch according to claim 2, wherein: The first gas inlet of the plasma excitation gas channel, the second gas inlet of the process gas channel and the third gas inlet of the raw material gas channel are all located at one end of the channel away from the burner port.

9. The plasma torch according to claim 1, wherein: The radio frequency induction coil is hollow to form a passage for circulating cooling water.

10. The plasma torch according to claim 1, wherein The material of the blowtorch body is quartz.

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