Plasma processing device and thin film deposition equipment

Abstract

The utility model discloses a plasma processing device and thin film deposition equipment, the plasma processing device comprises a plasma cavity and a radioactive source assembly, a discharge cavity is formed in the plasma cavity, the plasma cavity is provided with a cavity wall for isolating the discharge cavity from the outside, and the radioactive source assembly is arranged in the cavity wall. The radioactive source assembly is arranged on the cavity wall; wherein the radioactive source assembly is configured to penetrate through the cavity wall to radiate towards the interior of the discharge cavity; and / or the radioactive source assembly is configured to be partially exposed out of the discharge cavity so as to directly radiate towards the interior of the discharge cavity. According to the utility model, the interior of the discharge cavity is radiated by utilizing the radioactive source assembly, and the radioactive source can penetrate through the cavity wall, enter the interior of the discharge cavity, excite gas in the discharge cavity and generate more free electrons, so that the ignition capability is enhanced, and the problem of difficulty in ignition is solved on the premise that the ignition voltage is not increased.

Description

Technical Field

[0001] This utility model relates to the field of semiconductor technology, and in particular to a plasma processing device and a thin film deposition equipment. Background Technology

[0002] Remote Plasma Sources (RPS) are an indispensable part of modern semiconductor manufacturing processes, playing a crucial role, especially in Chemical Vapor Deposition (CVD) technology. RPS can efficiently dissociate gases such as NF3 (nitrogen trifluoride), generating a large number of active fluorine atoms (F). These active species are essential for cleaning the PECVD (Plasma-Enhanced Chemical Vapor Deposition) chamber and for certain processes such as FCVD (Fluorine Chemical Vapor Deposition). By utilizing the plasma generated by RPS, deposits on the inner walls of the chamber can be effectively removed, ensuring a clean production environment and thus improving product quality and consistency. However, in practical applications, RPS faces a series of challenges, the most significant being the difficulty of ignition. When RPS is not used for extended periods or remains stationary, its internal chamber gradually adsorbs electronegative gases and moisture. This adsorption mainly originates from residual gas components diffused in during the deposition process or gases flowing back into the RPS from other areas. Adsorbed electronegative gas and water molecules trap free electrons, causing a sharp decrease in the electron concentration within the RPS (Reactive Plasma System). This not only increases the difficulty of ignition but may also affect the stability and uniformity of the plasma, negatively impacting subsequent process performance. Although increasing the discharge voltage can improve ignition, this method is prone to sparking or arcing, damaging the equipment and posing safety hazards. Utility Model Content

[0003] The embodiments of this utility model provide a plasma processing device and a thin film deposition equipment, which aim to solve the problem of difficult ignition of existing RPS without increasing the ignition voltage.

[0004] In a first aspect, the present invention provides a plasma processing device, comprising: a plasma cavity and a radiation source assembly, wherein a discharge cavity is formed inside the plasma cavity, the plasma cavity has a cavity wall that isolates the discharge cavity from the outside world, and the radiation source assembly is disposed on the cavity wall;

[0005] Wherein, the radiation source assembly is configured to penetrate the cavity wall and radiate into the discharge cavity; and / or, the radiation source assembly is configured to be partially exposed in the discharge cavity to radiate directly into the discharge cavity.

[0006] Furthermore, the radiation source of the radiation source assembly is a β source.

[0007] Furthermore, a thin-walled portion is formed on the cavity wall, the thickness of the thin-walled portion being less than the thickness of the cavity wall, and the radiation source assembly is mounted on the thin-walled portion.

[0008] Furthermore, the thickness of the thin-walled portion is 0.5mm-2mm.

[0009] Furthermore, the cavity wall is provided with a mounting hole that penetrates the cavity wall, and the radiation source assembly is mounted on the mounting hole, with a portion of the radiation source assembly exposed in the discharge cavity.

[0010] Furthermore, a sealing element is provided between the radiation source assembly and the cavity wall.

[0011] Furthermore, an ignition electrode gap is formed on the cavity wall, and the radiation source assembly is disposed close to the ignition electrode gap, with a distance of 5mm-50mm between the radiation source assembly and the ignition electrode gap.

[0012] Furthermore, the discharge cavity is an annular cavity, and multiple radiation source assemblies are arranged around the annular cavity on the cavity wall.

[0013] Furthermore, the radiation assembly includes a shielding shell and a radiation block, the radiation block being disposed within the shielding shell, and the shielding shell having an opening on the side facing the discharge cavity.

[0014] Furthermore, the thickness of the shielding shell is 5mm-10mm.

[0015] Furthermore, the radiation block is an aluminum block, and the aluminum block itself is mixed with radioactive elements; and / or,

[0016] The surface of the cavity wall facing the discharge cavity is coated with a coating containing radioactive elements.

[0017] Furthermore, the shielding shell is threadedly connected to the cavity wall.

[0018] Secondly, this utility model also provides a thin film deposition apparatus, including the plasma processing device described above.

[0019] This invention provides a plasma processing device and a thin film deposition equipment. The plasma processing device includes a plasma cavity and a radiation source assembly. The plasma cavity has a discharge cavity inside, and the cavity wall of the plasma cavity isolates the discharge cavity from the outside. The radiation source assembly is disposed on the cavity wall and radiates into the discharge cavity. The radiation source can penetrate the cavity wall and enter the discharge cavity, or it can enter the discharge cavity directly without penetrating the cavity wall, exciting the gas inside the discharge cavity and generating more free electrons, thereby enhancing the ignition capability and improving the problem of ignition difficulty without increasing the ignition voltage. Attached Figure Description

[0020] To more clearly illustrate the technical solutions of the embodiments of this utility model, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0021] Figure 1 A schematic diagram of the plasma processing apparatus according to an embodiment of the present invention is shown;

[0022] Figure 2 A schematic diagram of another embodiment of the plasma processing apparatus of this utility model is shown;

[0023] Figure label:

[0024] 1. Plasma cavity; 11. Cavity wall; 111. Thin-walled section; 112. Mounting hole; 12. Discharge cavity; 13. Ignition electrode gap; 14. Inlet; 15. Outlet; 16. Coating; 2. Radiation source assembly; 21. Shielding shell; 22. Radiation block; 23. Sealing element. Detailed Implementation

[0025] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of the present utility model.

[0026] The directional terms used in this invention, such as "up," "down," "front," "back," "left," "right," "inner," "outer," and "side," are merely for reference to the accompanying drawings. Therefore, the directional terms used are for explanation and understanding of this invention, and not for limiting it. Furthermore, in the accompanying drawings, structures that are similar or identical are indicated by the same reference numerals.

[0027] Existing remote plasma sources (RPS) sometimes experience ignition difficulties during use, especially after the equipment has been idle for a period of time. Specifically, when an RPS is not used for an extended period, its internal chambers adsorb electronegative gases and water vapor. These gases may originate from residual gas components diffused or flowing back during the deposition process. The adsorbed electronegative gases and water vapor trap free electrons, reducing the electron concentration within the chamber and thus increasing the difficulty of ignition. Furthermore, after each cleaning process, if the equipment is left to stand for a period of time, positive and negative charges gradually recombine and dissipate, further reducing the number of free electrons within the chamber, making subsequent ignition even more difficult. Conversely, if the equipment continuously processes wafers (i.e., "wafer runs"), and the RPS is used for cleaning immediately after each wafer deposition, a certain number of free electrons remain within the chamber, making ignition problems less likely. Therefore, current RPS systems experience ignition difficulties after a period of idle time due to the adsorption of electronegative gases and water vapor within the internal chambers, leading to a decrease in the free electron concentration.

[0028] To address this issue, this invention provides a plasma processing device and a thin film deposition equipment, which solves the problem of difficult ignition of existing RPS devices. By radiating the discharge cavity through the radiation source assembly, more free electrons are generated, thereby enhancing the ignition capability.

[0029] To solve the aforementioned problem of ignition difficulty, the present invention provides the following specific approach:

[0030] Adding a radiation source assembly, which is installed on the wall of the plasma cavity, allows the radiation source assembly to radiate into the discharge cavity within the plasma cavity. The decay of the radiation source generates an additional electron beam that enters the discharge cavity. The electron beam collides with gas molecules, causing ionization and producing more free electrons. This increases the number and concentration of free electrons. When there is a high concentration of free electrons in the discharge cavity, gas molecules have more opportunities to collide with these electrons and are more easily ionized. Once some gas molecules are ionized, the additional electrons and positive ions generated will further trigger more collisional ionization events, forming an "avalanche" effect. This rapidly increases the plasma density, thereby promoting ignition, enhancing ignition capability, and improving the problem of difficult ignition after settling.

[0031] To better understand the above technical solutions, the following will provide a detailed explanation of the technical solutions in conjunction with the accompanying drawings and specific implementation methods.

[0032] Please see Figures 1-2This utility model embodiment illustrates a plasma processing device, including: a plasma cavity 1 and a radiation source assembly 2. The plasma cavity 1 has a discharge cavity 12 formed inside it. The plasma cavity has a cavity wall 11 that isolates the discharge cavity 12 from the outside world. The radiation source assembly 2 is disposed on the cavity wall 11. The radiation source assembly 2 is configured to penetrate the cavity wall 11 and radiate into the discharge cavity 12; and / or, the radiation source assembly 2 is configured to be partially exposed in the discharge cavity 12 to radiate directly into the discharge cavity 12.

[0033] Specifically, the plasma cavity 1 is the core component of the plasma processing device, and a discharge cavity 12 is formed inside it for generating and maintaining plasma. Its cavity wall 11 isolates the discharge cavity 12 from the outside environment, ensuring the stability and safety of the plasma generation environment. The radiation source assembly 2 is mounted on the cavity wall 11. The mounting structure of the radiation source assembly 2 and the cavity wall 11 can be of various forms and is not limited here. The radiation source assembly 2 has two radiation paths: one is that the radiation source penetrates the cavity wall 11 to enter the discharge cavity 12; the other is that it does not need to penetrate the cavity wall 11 but is partially exposed in the discharge cavity 12, with the radiation source directly entering the discharge cavity 12. Both radiation paths can effectively radiate the interior of the discharge cavity 12.

[0034] Specifically, the radiation source assembly 2 is disposed on the cavity wall 11 and configured to penetrate the cavity wall 11 to radiate into the discharge cavity 12. Since the cavity is typically made of aluminum, alpha rays have weak penetrating power while gamma rays have strong penetrating power. Therefore, this embodiment uses beta rays with moderate penetrating power. Thus, the radiation source of the radiation source assembly 2 in this embodiment can be a beta source, such as carbon-14 isotope, whose maximum beta particle energy is approximately 0.156 MeV, which can provide sufficient electron injection without causing excessive radiation risk. Other possible options include tritium (H-3) or nickel-63, depending on application requirements and safety requirements. High-speed electrons (i.e., beta particles) are released through beta decay. These high-energy electrons can penetrate the cavity wall 11 and enter the discharge cavity 12, colliding with gas molecules, exciting or ionizing the gas molecules, and generating additional free electrons. Therefore, by radiating β particles into the discharge cavity 12 through the radiation source assembly 2 penetrating the cavity wall 11, additional free electrons can be generated in the discharge cavity 12, increasing the free electron concentration, overcoming the problem of electron reduction caused by adsorption effect, and improving the ignition success rate.

[0035] It is understandable that the radiation source assembly 2 can also be partially exposed inside the discharge cavity 12, directly radiating into the interior of the discharge cavity 12. The radiation source of the radiation source assembly 2 can be selected to be a type of radiation with weak penetrating power. By partially exposing the radiation source assembly 2 inside the discharge cavity 12, β particles can be directly radiated into the discharge cavity 12, generating additional free electrons and increasing the background electron concentration. Direct radiation can more efficiently introduce β particles into the discharge cavity 12, reducing energy loss when penetrating the cavity wall 11 and further improving ignition efficiency.

[0036] In this embodiment, by having the radiation source component 2 penetrate the cavity wall 11 and partially expose itself inside the discharge cavity 12, the concentration of free electrons in the discharge cavity 12 is increased, enhancing the ignition capability. This allows for effective ignition without increasing the ignition voltage, thereby improving the success rate and stability of ignition.

[0037] Reference Figure 1 In one embodiment, a thin-walled portion 111 is formed on the cavity wall 11, the thickness of which is less than the thickness of the cavity wall 11. The radiation source assembly 2 is mounted on the thin-walled portion 111. Specifically, the cavity wall 11 is part of the plasma cavity 1, used to isolate the discharge cavity 12 from the external environment. The plasma cavity 1 is an aluminum cavity. The thin-walled portion 111 is a thinner section in a specific area of ​​the cavity wall 11, its thickness being less than that of other parts of the cavity wall 11. The purpose of the thin-walled portion 111 is to allow the radiation source to penetrate through the thin-walled portion 111 and enter the interior of the discharge cavity 12, while the other parts of the cavity wall 11 are thicker, preventing the radiation source from passing through. That is, the cavity wall 11 acts as a shielding structure to prevent radiation leakage. In a specific implementation, the thin-walled portion 111 can be a mounting groove for mounting the radiation source assembly 2. This mounting groove is recessed towards the discharge cavity 12, and therefore its thickness is thinner than the gas portion of the cavity wall 11. The radioactive source assembly 2 is installed in the mounting slot, for example, by interference fit, threaded fit, screw fastening, etc., which is not limited here. In this embodiment, in order to ensure the safety and reliability of the radioactive source, a thin-walled portion 111 is formed on the cavity wall 11, and the radioactive source assembly 2 is installed on the thin-walled portion 111, so that the radioactive source can only penetrate the thin-walled portion 111 to enter the discharge cavity 12, while the other parts of the cavity wall 11 are shielded, and the radioactive source cannot penetrate, protecting the operators and equipment from unnecessary radiation and ensuring that radiation leakage meets safety standards.

[0038] In this embodiment, the thickness of the thin-walled portion 111 is 0.5mm-2mm. Specifically, in practical applications, if the thin-walled portion 111 is too thick, the energy loss during radiation source penetration is greater, resulting in poor ignition effect. If the thin-walled portion 111 is too thin, the mechanical strength of the cavity wall 11 is insufficient, affecting the overall structural stability of the cavity. Therefore, the thickness of the thin-walled portion 111 is within a preferred feasible range. In this embodiment, the thickness of the thin-walled portion 111 can be 0.5mm. When the thickness of the thin-walled portion 111 is 0.5mm, the energy loss during β-particle penetration is minimized, allowing more high-energy electrons to smoothly enter the discharge cavity 12, while the wall thickness still maintains a certain mechanical strength. The thickness of the thin-walled portion 111 can also be 2mm. When the thickness of the thin-walled portion 111 is 2mm, the energy loss during β-particle penetration is within an acceptable range, ensuring sufficient high-energy electrons enter the discharge cavity 12. The 2mm thickness provides better mechanical strength and radiation shielding effect, ensuring the safety and reliability of the cavity wall 11. Of course, the thickness of the thin-walled portion 111 can also be 1mm, 1.5mm, or other values, which are not limited here. It is evident that a thickness range of 0.5mm to 2mm can find the optimal balance between reducing energy loss and ensuring mechanical strength. The specific choice can be adjusted according to actual application requirements. For example, a thickness close to 0.5mm can be chosen when higher radiation efficiency is required; while a thickness close to 2mm can be chosen when better mechanical strength and radiation shielding are needed.

[0039] Reference Figure 2In one embodiment, a mounting hole 112 is provided on the cavity wall 11, the mounting hole 112 penetrating the cavity wall 11, and the radioactive source assembly 2 is mounted in the mounting hole 112, with a portion of the radioactive source assembly 2 exposed in the discharge cavity 12. Specifically, the mounting hole 112 is a through hole opened in the cavity wall 11 for mounting the radioactive source assembly 2, and the mounting hole 112 connects to the outside and the discharge cavity 12. The radioactive source assembly 2 is installed in the mounting hole 112, and the shape, diameter, and depth of the mounting hole 112 match the radioactive source assembly 2 to ensure that the radioactive source assembly 2 can be installed safely and stably. The radioactive source assembly 2 can be installed in the mounting hole 112 by mechanical fixing, welding, or bonding, etc., which is not limited here. When the radioactive source assembly 2 is installed into the mounting hole 112, it isolates the outside world from the discharge cavity 12. A portion of the radioactive source assembly 2 is directly exposed inside the discharge cavity 12. Therefore, the radiation source can directly enter the discharge cavity 12. The radioactive source assembly 2, which is directly exposed inside the discharge cavity 12, can more efficiently introduce β particles into the discharge cavity 12, reducing energy loss when penetrating the cavity wall 11, reducing penetration resistance, and further improving ignition efficiency. In this embodiment, by opening the mounting hole 112 in the cavity wall 11 and installing the radioactive source assembly 2 into the mounting hole 112, a portion of the radioactive source assembly 2 is directly exposed inside the discharge cavity 12, effectively increasing the number of high-energy electrons entering the discharge cavity 12, increasing the free electron concentration, and thus improving ignition performance.

[0040] In this embodiment, a sealing element 23 is also provided between the radioactive source assembly 2 and the cavity wall 11. Specifically, since a through mounting hole 112 is opened in the cavity wall 11, there is a risk of gas leakage inside the discharge cavity 12, making it difficult to maintain a vacuum. Therefore, this embodiment improves the sealing performance of the discharge cavity 12 by providing a sealing element 23. Specifically, the sealing element 23 can be a sealing ring, which can be fitted around the outer periphery of the radioactive source assembly 2. The sealing ring is located in the mounting hole 112, with its inner wall in close contact with the radioactive source assembly 2 and its outer wall in close contact with the wall of the mounting hole 112. In another installation method, the sealing ring can be pressed against the cavity wall 11 by the radiation source assembly 2. The radiation source assembly 2 includes a cylindrical shielding shell 21, which is divided into two sections with different diameters: an inner shell section with a smaller diameter and an outer shell section with a larger diameter. The inner shell section is installed with the mounting hole 112, and the outer shell section is outside the plasma cavity. The sealing ring is fitted onto the inner shell section, and the end face of the outer shell section facing the cavity wall 11 presses the sealing ring against the cavity wall 11, thereby achieving a seal. By setting a seal 23 between the radiation source assembly 2 and the cavity wall 11, gas leakage and external contaminants can be effectively prevented from entering the discharge cavity 12, ensuring that the inside of the plasma cavity 1 is a vacuum, while reducing radiation leakage around the radiation source assembly 2 and improving safety.

[0041] In one embodiment, an ignition electrode gap 13 is formed on the cavity wall 11, and the radiation source assembly 2 is disposed close to the ignition electrode gap 13. The distance between the radiation source assembly 2 and the ignition electrode gap 13 is 5mm-50mm. Specifically, the ignition electrode gap 13 is the space between two electrodes formed on the cavity wall 11, used to initiate plasma discharge. By applying a high voltage between the electrodes, a spark or arc discharge is generated, exciting gas molecules and producing initial free electrons and positive ions. The ignition electrode gap 13 is formed by splicing cavities, with the two ends of the ignition electrode gap 13 being spliced ​​cavities, i.e., the spliced ​​cavities serve as electrodes. The radiation source assembly 2 is installed on the cavity wall 11, disposed close to the ignition electrode gap 13. This effectively increases the concentration of free electrons near the ignition electrode gap 13. The high-energy electrons released by the radiation source can directly enter the region of the ignition electrode gap 13 or be near the ignition electrode gap 13, increasing the probability of collision with gas molecules, exciting or ionizing gas molecules, generating additional free electrons, and improving the success rate of ignition. The distance between the radiation source assembly 2 and the ignition electrode gap 13 should be controlled between 5mm and 50mm. This distance range ensures that β particles can effectively reach the ignition electrode gap 13 while avoiding the risk of radiation leakage due to excessively close proximity. The specific selection can be adjusted according to actual application or process requirements, as long as it is within the above-mentioned distance range, ensuring optimal radiation efficiency and safety. In other embodiments, multiple ignition electrode gaps 13 can be set at different positions on the cavity wall 11, with a radiation source assembly 2 installed near each ignition electrode gap 13 to achieve a more uniform discharge distribution and further improve the ignition effect.

[0042] In this embodiment, the discharge cavity 12 is an annular cavity, and multiple radiation source components 2 are arranged around the annular cavity on the cavity wall 11. Specifically, the discharge cavity 12 has an annular structure with a ring-shaped cross-section, providing a larger surface area and more uniform internal space, ensuring uniform plasma distribution throughout the cavity. The annular cavity can be assembled from multiple independent cavities, facilitating manufacturing, installation, and maintenance. The assembly structure can be fixed using mechanical connectors (such as bolts or clips) or welding to ensure the sealing and stability between the cavities. An inlet 14 and an outlet 15 are respectively provided at the top and bottom of the annular cavity. NF3 enters the discharge cavity 12 through the inlet 14, dissociates into fluorine atoms, and is discharged through the outlet 15. Multiple radiation source components 2 are arranged around the annular cavity on the cavity wall 11 to ensure that each region within the discharge cavity 12 receives sufficient free electrons. The number and position of the radiation source components 2 can be optimized according to specific application requirements to achieve the best electron injection effect. It is understandable that multiple ignition electrode gaps 13 can be set at different positions in the annular cavity, and combined with the more free electrons provided by the radiation source assembly 2, the success rate and stability of ignition can be further improved. In this embodiment, multiple radiation source assemblies 2 are arranged around the cavity wall 11 of the annular cavity, so that each region in the discharge cavity 12 can obtain sufficient free electrons, which can significantly improve the success rate and stability of ignition.

[0043] In one embodiment, the radiation assembly includes a shielding shell 21 and a radiation block 22, the radiation block 22 being disposed within the shielding shell 21, and the shielding shell 21 having an opening on the side facing the discharge cavity 12. Specifically, plasma processing devices face the risk of radiation leakage and the problem of radiation efficiency when using a radiation source. To improve the safety and effectiveness of radiation, this embodiment provides a solution by designing the radiation source assembly 2 to include a shielding shell 21 and a radiation block 22, with the shielding shell 21 having an opening on the side facing the discharge cavity 12. This solution can effectively reduce unnecessary radiation leakage, ensure that high-energy electrons concentrate and enter the discharge cavity 12 from the opening, while maintaining good radiation efficiency.

[0044] Specifically, the shielding shell 21 is used to enclose the radiation block 22 to prevent radiation leakage in unwanted directions. The shielding shell 21 has an opening on the side facing the discharge cavity 12, while the other sides are completely covered by shielding material. The shielding shell 21 can be a high-density, radiation-resistant material, such as lead, tungsten, or stainless steel. The shielding shell 21 can be designed as a sleeve structure with one side closed and the other side open, or with an opening. The outer periphery of the shielding shell 21 is provided with external threads, and the thin-walled portion 111 is provided with internal threads. The shielding shell 21 is threadedly connected to the thin-walled portion 111 on the cavity wall 11, and the radiation block 22 is placed inside the shielding shell 21. When the shielding shell 21 is installed on the thin-walled portion 111, the side with the opening faces the discharge cavity 12 and the thin-walled portion 111, so that the radiation block 22 also faces the thin-walled portion 111 on this side. The radiation block 22 and the discharge cavity 12 are separated only by the thin-walled portion 111. The high-speed electrons released by the radiation block 22 can only be emitted from this opening; all other locations are shielded by the shielding shell 21. The electron beam directly penetrates the thin-walled portion 111 through the opening and enters the discharge cavity 12. This ensures that high-energy electrons concentrate and enter the discharge cavity 12 from the opening, reducing unnecessary radiation leakage and penetration resistance. This achieves directional radiation inside the discharge cavity 12, improving radiation efficiency and ensuring that more high-energy electrons can effectively excite gas molecules to generate additional free electrons. Through this embodiment, the radiation source can directly penetrate the thin-walled portion 111 through the opening and enter the discharge cavity 12, reducing penetration resistance and improving radiation efficiency. Simultaneously, the design of the shielding shell 21 effectively blocks radiation, preventing leakage to the external environment and ensuring the safety of operators and equipment.

[0045] In this embodiment, the thickness of the shielding shell 21 is 5mm-10mm. Specifically, to ensure radiation safety, the thickness of the shielding shell 21 needs to be greater than the thickness of the thin-walled portion 111. This allows radiation to penetrate the thin-walled portion 111 and enter the discharge cavity 12, but prevents it from penetrating other parts of the cavity wall 11, thus preventing radiation leakage to the external environment. Therefore, the thickness of the shielding shell 21 does not need to be too thick, which increases material costs, but it must be greater than the thickness of the thin-walled portion 111, thus there is an optimal thickness range. Specifically, the thickness of the shielding shell 21 can be controlled between 5mm and 10mm, finding the optimal balance between radiation shielding effect and material cost. The specific choice can be adjusted according to actual application requirements. For example, a thickness close to 10mm can be chosen when a higher shielding effect is required; while a thickness close to 5mm can be chosen when cost reduction or weight reduction is needed. Of course, other thickness values ​​are also possible.

[0046] In one embodiment, the radiation block 22 is an aluminum block mixed with radioactive elements. Specifically, the radiation block 22 is the core part of the radiation source, used to release high-speed electrons (i.e., β particles) through β decay. These high-energy electrons can enter the discharge cavity 12, exciting or ionizing gas molecules and generating additional free electrons. The radiation block 22 is made of aluminum, which has good conductivity, is lightweight, and easy to process. The shape of the aluminum block matches the interior of the shielding shell 21. The aluminum block itself is mixed with radioactive elements, which are uniformly mixed into the aluminum block through a doping process, so that the aluminum block can radiate outwards as a radiation source.

[0047] In one embodiment, a coating 16 is provided on the surface of the cavity wall 11 facing the discharge cavity 12, and the coating 16 is mixed with radioactive elements. Specifically, in order to further improve the success rate and stability of ignition, a coating 16 containing radioactive elements is provided on the surface of the cavity wall 11 facing the discharge cavity 12, that is, the inner surface. This coating 16 is mixed with radioactive elements and can continuously release β particles on the inner surface of the cavity wall 11, exciting gas molecules inside the discharge cavity 12, generating more free electrons, increasing the free electron concentration, thereby improving the success rate and stability of ignition.

[0048] This utility model also provides a thin film deposition apparatus, including the plasma processing device described in the above embodiments. The plasma processing device has been described in detail in the above embodiments, and for the sake of brevity, it will not be repeated here.

[0049] In this embodiment, the radiation source assembly 2 is used to radiate the interior of the discharge cavity 12. The radiation source can penetrate the cavity wall 11 and enter the interior of the discharge cavity 12, exciting the gas inside the discharge cavity 12 and generating more free electrons, thereby enhancing the ignition capability and improving the problem of ignition difficulty without increasing the ignition voltage.

[0050] The above description is merely a specific embodiment of this utility model, but the protection scope of this utility model is not limited thereto. Any person skilled in the art can easily conceive of various equivalent modifications or substitutions within the technical scope disclosed in this utility model, and these modifications or substitutions should all be covered within the protection scope of this utility model. Therefore, the protection scope of this utility model should be determined by the scope of the claims.

Claims

1. A plasma processing device, characterized in that, The application relates to a plasma processing device. The plasma processing device comprises a plasma cavity and a radiation source assembly, wherein the plasma cavity is internally formed with a discharge cavity, the plasma cavity is provided with a cavity wall for isolating the discharge cavity from the outside, and the radiation source assembly is arranged on the cavity wall. The radiation source assembly is configured to penetrate the cavity wall to radiate the inside of the discharge cavity, and / or the radiation source assembly is configured to be partially exposed to the discharge cavity to directly radiate the inside of the discharge cavity.

2. The plasma processing apparatus of claim 1, wherein, The radiation source of the radiation source assembly is a beta source.

3. The plasma processing apparatus of claim 1, wherein, The cavity wall is formed with a thin wall part, the thickness of the thin wall part is smaller than that of the cavity wall, and the radiation source assembly is arranged on the thin wall part.

4. The plasma processing apparatus of claim 3, wherein, The thickness of the thin wall part is 0.5-2 mm.

5. The plasma processing apparatus of claim 1, wherein, The cavity wall is provided with a mounting hole penetrating the cavity wall, the radiation source assembly is arranged on the mounting hole, and part of the radiation source assembly is exposed to the discharge cavity.

6. The plasma processing apparatus of claim 1, wherein, A sealing element is arranged between the radiation source assembly and the cavity wall.

7. The plasma processing apparatus of claim 1, wherein, The cavity wall is formed with an ignition electrode gap, the radiation source assembly is arranged close to the ignition electrode gap, and the distance between the radiation source assembly and the ignition electrode gap is 5-50 mm.

8. The plasma processing apparatus of claim 1, wherein, The discharge cavity is a ring-shaped cavity, and a plurality of radiation source assemblies are arranged on the cavity wall around the ring-shaped cavity.

9. The plasma processing apparatus of any of claims 1-8, wherein, The radiation source assembly comprises a shielding shell and a radiation block, the radiation block is arranged in the shielding shell, and the shielding shell is provided with an opening on the side facing the discharge cavity.

10. The plasma processing apparatus of claim 9, wherein, The thickness of the shielding shell is 5-10 mm.

11. The plasma processing apparatus of claim 9, wherein, The radiation block is an aluminum block, the aluminum block is mixed with radioactive elements, and / or The surface of the cavity wall on the side facing the discharge cavity is provided with a coating mixed with radioactive elements.

12. The plasma processing apparatus of claim 9, wherein, The shielding shell is threadedly connected with the cavity wall.

13. A thin film deposition apparatus, characterized by, The application further relates to a plasma processing device comprising any one of the above-mentioned plasma processing devices.

Images