Large-area microwave plasma excitation device

Abstract

The utility model relates to the technical field of plasma excitation, and particularly discloses a large-area microwave plasma excitation device which comprises an excitation cavity provided with a gas outlet and a gas inlet, an excitation piece installed in the excitation cavity, microwave sources connected with the two ends of the excitation piece respectively, and a gas supply system communicated with the gas inlet. The excitation part comprises an outer glass tube, an inner glass tube which is coaxially sleeved in the outer glass tube and forms an annular cavity, a non-uniform coil which is mounted in the cavity and coaxially sleeved on the outer side of the inner glass tube, and a metal rod which is coaxially sleeved in the inner glass tube and of which the two ends penetrate through the excitation cavity and are connected with the microwave source. According to the utility model, the outer side of the inner glass tube is sleeved with the non-uniform coil, so that the uniform distribution of an electromagnetic field in the excitation cavity is effectively realized, the stable generation and maintenance of microwave plasmas are realized, and the uniformity of the plasma device is improved.

Description

Technical Field

[0001] The utility model relates to the technical field of plasma excitation, and more particularly to a large-area microwave plasma excitation device. Background Art

[0002] Currently, plasma devices have demonstrated tremendous application potential and value in the materials processing and semiconductor industries. Plasma-enhanced vapor deposition (PECVD) is commonly used to manufacture thin films for solar cells. In PECVD technology, the non-uniformity of plasma density and stability will seriously affect the uniformity of thin film deposition. This non-uniformity not only reduces the quality of the film, but also further affects the performance and efficiency of solar cells, thereby limiting their widespread application in the energy field. In addition, plasma cleaning technology, as an important cleaning method in the semiconductor industry, plays an irreplaceable role in improving production efficiency and product quality. However, to achieve high-efficiency cleaning, it is necessary to ensure the uniformity of the plasma device to avoid problems such as incomplete or excessive local cleaning during the cleaning process.

[0003] Microwaves are a highly efficient method for plasma generation, offering advantages such as continuous, stable power output, low cost, and ease of operation. Consequently, they are widely used in plasma technology. However, when microwave plasma devices are applied to large-scale plasma generation, they face a number of challenges. As device size increases, edge effects significantly increase, leading to a decrease in plasma uniformity and severely impacting the effectiveness and reliability of large-scale plasma technology in industrial applications. Utility Model Content

[0004] The technical problem to be solved by the utility model is to provide a large-area microwave plasma excitation device;

[0005] The solution adopted by the utility model to solve the technical problem is:

[0006] A large-area microwave plasma excitation device comprises an excitation cavity provided with a gas outlet and a gas inlet, an excitation member installed in the excitation cavity, a microwave source connected to both ends of the excitation member, and a gas supply system connected to the gas inlet;

[0007] The excitation component includes an outer glass tube, an inner glass tube coaxially sleeved in the outer glass tube to form an annular chamber, a non-uniform coil installed in the chamber and coaxially sleeved on the outside of the inner glass tube, and a metal rod coaxially sleeved in the inner glass tube and with both ends passing through the excitation cavity and connected to the microwave source.

[0008] In some possible implementations, the non-uniform coil includes two groups of symmetrically arranged ends and a connecting portion located between the two groups of ends, and the number of turns of the ends is smaller than the number of turns of the connecting portion.

[0009] In some possible implementations, the outer glass tube, the inner glass tube, and the non-uniform coil have equal lengths along their axial directions, and both ends of the outer glass tube are respectively sealed to the inner side surfaces of the excitation cavity.

[0010] In some possible implementations, coaxial feeding ports connected to both ends of the metal rod are provided on the outside of the excitation cavity.

[0011] In some possible implementations, the microwave source and the coaxial feed port are connected via a coaxial transmission line.

[0012] In some possible implementations, the excitation members are in multiple groups with the same structure, and the number of the microwave sources is twice the number of the excitation members.

[0013] In some possible implementations, the distances between two adjacent groups of the excitation members are equal, and the axes of the multiple groups of the excitation members are in the same plane and parallel to the bottom of the excitation cavity.

[0014] In some possible implementations, the excitation member divides the excitation chamber into an upper chamber and a lower chamber; when the gas inlet is connected to the upper chamber, the gas outlet is connected to the lower chamber; when the gas outlet is connected to the upper chamber, the gas inlet is connected to the lower chamber.

[0015] In some possible implementations, a gap between an outer side surface of the non-uniform coil and the outer glass tube is 0-1 mm.

[0016] Compared with the prior art, the present invention has the following beneficial effects:

[0017] The utility model effectively realizes the uniform distribution of the electromagnetic field in the excitation cavity by sheathing a non-uniform coil on the outer side of the inner glass tube, thereby realizing the stable generation and maintenance of microwave plasma and improving the uniformity of the plasma device;

[0018] The utility model effectively prevents process gas from entering the excitation component and causing corrosion to the excitation component through the sealed connection between the excitation component and the excitation cavity;

[0019] The utility model greatly improves the utilization rate of process gas by arranging the gas inlet and the gas outlet. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 This is a schematic diagram of the connection relationship of the utility model;

[0021] Figure 2 This is a schematic diagram of the structure of the excitation cavity, microwave source, and excitation element in the utility model;

[0022] Figure 3 This is a schematic diagram of the structure of the present invention when there are multiple groups of excitation members;

[0023] Among them: 1. Excitation cavity; 11. Gas inlet; 12. Gas outlet; 13. Coaxial feed port; 2. Excitation element; 21. Outer glass tube; 22. Non-uniform coil; 23. Inner glass tube; 24. Metal rod; 3. Microwave source; 4. Gas supply system; 5. Coaxial transmission line. DETAILED DESCRIPTION

[0024] In this application, unless otherwise specified or limited, terms such as "mounted," "connected," "connect," and "fixed" should be interpreted broadly. For example, they can refer to fixed connections, removable connections, or integration; they can refer to direct connections or indirect connections through an intermediary; they can refer to internal communication between two components or interactions between two components. The terms "first," "second," and similar terms mentioned in this application do not denote any order, quantity, or importance; they are simply used to distinguish between different components. Similarly, terms such as "a" or "an" do not indicate a quantitative limitation; rather, they indicate the presence of at least one. In the implementation of this application, "and / or" describes an association relationship between associated objects, indicating that three possible relationships exist. For example, "A and / or B" can mean: A exists alone, A and B exist simultaneously, or B exists alone. In the description of the embodiments of this application, unless otherwise specified, "plurality" means two or more. For example, "plurality" refers to two or more positioning posts. Those skilled in the art will understand the specific meanings of these terms in this application based on the specific circumstances.

[0025] The utility model is described in detail below.

[0026] like Figure 1-Figure 3 As shown:

[0027] A large-area microwave plasma excitation device includes an excitation chamber 1 provided with a gas outlet 12 and a gas inlet 11, an excitation member 2 installed in the excitation chamber 1, a microwave source 3 connected to both ends of the excitation member 2, and a gas supply system 4 connected to the gas inlet 11;

[0028] The excitation component 2 includes an outer glass tube 21, an inner glass tube 23 coaxially sleeved in the outer glass tube 21 to form an annular chamber, a non-uniform coil 22 installed in the chamber and coaxially sleeved on the outside of the inner glass tube 23, and a metal rod 24 coaxially sleeved in the inner glass tube 23 and with both ends passing through the excitation cavity 1 and connected to the microwave source 3; the gap between the outer side surface of the non-uniform coil 22 and the outer glass tube 21 is 0-1mm.

[0029] In the present invention, the excitation chamber 1 has enough space for gas flow; the gas inlet 11 and the gas outlet 12 are provided in the excitation chamber 1 for the gas to enter and exit;

[0030] In the present invention, the metal rod 24 serves as a transmission medium for microwave energy and an excitation source for plasma; the metal rod 24 is placed in the inner glass tube and coaxially arranged with the inner glass tube 23, and the metal rod 24 is connected to the microwave source 3 to enable the microwave energy to be transmitted to the process gas.

[0031] In the present invention, the inner glass tube 23 is used to protect the metal rod 24 from plasma corrosion.

[0032] In the present invention, the non-uniform coil 22 is a metal coil, which is arranged between the inner glass tube 23 and the outer glass tube 21 to adjust the distribution of the electric field and optimize the generation of plasma. In actual use, when only the metal rod 24 is used as the inner conductor, the device will show a situation where the electric field is strong at both ends and weak in the middle. To this end, the shape, position and number of turns of the non-uniform coil 22 can be adjusted according to the specific design to better couple the electric field in the middle part, thereby achieving a more uniform electric field distribution. Ultimately, a more uniform plasma is excited by the uniform electric field.

[0033] The outer glass tube 21 of the utility model is used to provide isolation and protect the non-uniform coil 22 from plasma corrosion; the outer glass tube and the inner glass tube 23 are coaxially arranged and wrap the non-uniform coil 22 and the inner glass tube 23 to ensure the stability and safety of the entire device. The two ends of the metal rod 24 will pass through the two ends of the outer glass tube 21 and connect to the microwave source 3.

[0034] The excitation cavity 1 of the present invention serves as a generation and maintenance area for microwave plasma, can accommodate the excitation component 2, and ensure that microwave energy can be effectively transmitted and reflected in the cavity.

[0035] The gas outlet 12 and the gas inlet 11 are used to introduce process gas (such as argon, nitrogen, etc.) and discharge the reacted gas; the gas supply system 4 is connected to the gas inlet 11 through a pipeline to transport the process gas into the excitation chamber 1 to ensure that the process gas can be continuously and stably injected into the reaction chamber.

[0036] During operation, the gas supply system 4 supplies process gas into the excitation chamber 1 through the gas inlet 11. The microwave source 3 transmits microwave energy into the excitation chamber 1 via the metal rod 24. This microwave energy generates a strong electromagnetic field through the metal rod 24-inner glass tube 23-non-uniform coil 22-outer glass tube 21 structure. Under the influence of this strong electromagnetic field, the process gas molecules in the reaction chamber undergo a chemical reaction, ionizing them to form a plasma. During this process, the electric field energy is converted into plasma energy with a high electron density and high electron temperature. The reacted gas is discharged through the gas outlet 12. The output power and frequency of the microwave source 3 can be adjusted to meet different plasma generation requirements.

[0037] In some possible embodiments, the non-uniform coil 22 includes two groups of symmetrically arranged ends and a connecting portion located between the two groups of ends. The number of turns of the ends is smaller than the number of turns of the connecting portion, that is, the non-uniform coil 22 has a structure that is dense in the middle and loose on both sides, presenting a non-uniform arrangement. The distribution of the microwave electric field in the reaction chamber through the non-uniform arrangement of the non-uniform coil 22 enables the electric field to be better coupled in the middle part, thereby achieving a more uniform electric field distribution. Ultimately, a more uniform plasma is excited by the uniform electric field.

[0038] The uniformity of the electric field distribution is improved by adjusting the radial position (distance from the metal rod 24) and the number of turns of the non-uniform coil 22 in the axial direction (position along the length of the metal rod 24). The specific settings for the glass tube dimensions in the metal rod 24 - inner glass tube 23 - non-uniform coil 22 - outer glass tube 21, the metal rod 24 dimensions, the non-uniform coil 22 dimensions, and the number of turns of the non-uniform coil 22 at different positions along the inner glass tube can be determined based on the designed dimensions of the excitation chamber 1.

[0039] In some possible implementations, the outer glass tube 21 , the inner glass tube 23 , and the non-uniform coil 22 have equal lengths along their axial directions, and both ends of the outer glass tube 21 are sealed to the inner side surfaces of the excitation cavity 1 .

[0040] In some possible embodiments, in order to effectively connect the microwave source 3 and the metal rod 24 and realize the transmission of microwave energy, a coaxial feed port 13 connected to both ends of the metal rod 24 is provided on the outside of the excitation cavity 1; the microwave source 3 and the coaxial feed port 13 are connected via a coaxial transmission line 5.

[0041] In some possible implementations, the excitation members 2 are multiple groups with the same structure, and the number of the microwave sources 3 is twice the number of the excitation members 2 ; this configuration can achieve simultaneous transmission of microwave energy from both ends of the metal rod 24 .

[0042] In some possible embodiments, the distances between two adjacent groups of the excitation members 2 are equal, and the axes of the multiple groups of the excitation members 2 are in the same plane and parallel to the bottom of the excitation chamber 1; this arrangement can achieve uniform excitation of the plasma over a large range;

[0043] In some possible embodiments, the excitation member 2 divides the excitation chamber 1 into an upper chamber and a lower chamber; when the gas inlet 11 is connected to the upper chamber, the gas outlet 12 is connected to the lower chamber; when the gas outlet 12 is connected to the upper chamber, the gas inlet 11 is connected to the lower chamber; this setting will enable the process gas to fully react after entering the excitation chamber 1.

[0044] The present invention achieves uniform distribution of the electromagnetic field in the reaction chamber through components such as the metal rod 24, the inner glass tube, the non-uniform coil 22 with a dense structure in the middle and sparse structures on both sides, the outer glass tube and the reaction chamber, thereby achieving stable generation and maintenance of microwave plasma and improving the uniformity of the plasma device. A large-area, high-uniformity microwave plasma device is of great significance for improving the deposition quality and efficiency of solar cell thin films, and will also promote technological progress and industrial upgrading in related fields such as semiconductor cleaning technology.

[0045] The present invention is not limited to the aforementioned specific embodiments, but extends to any new features or any new combination disclosed in this specification, as well as any new method or process steps or any new combination disclosed.

Claims

1. A large-area microwave plasma excitation device, characterized in that: The invention comprises an excitation cavity provided with a gas outlet and a gas inlet, an excitation member installed in the excitation cavity, a microwave source connected to both ends of the excitation member, and a gas supply system connected to the gas inlet; The excitation component includes an outer glass tube, an inner glass tube coaxially sleeved in the outer glass tube to form an annular chamber, a non-uniform coil installed in the chamber and coaxially sleeved on the outside of the inner glass tube, and a metal rod coaxially sleeved in the inner glass tube and with both ends passing through the excitation cavity and connected to the microwave source.

2. A large-area microwave plasma excitation device according to claim 1, characterized in that: The non-uniform coil includes two groups of symmetrically arranged ends and a connecting portion located between the two groups of ends, and the number of turns of the ends is smaller than the number of turns of the connecting portion.

3. The large-area microwave plasma excitation device according to claim 1, characterized in that: The outer glass tube, the inner glass tube and the non-uniform coil have equal lengths along their axial directions, and both ends of the outer glass tube are respectively sealed and connected to the inner side surface of the excitation cavity.

4. The large-area microwave plasma excitation device according to claim 1, characterized in that: Coaxial feeding ports respectively connected to the two ends of the metal rod are arranged on the outside of the excitation cavity.

5. The large-area microwave plasma excitation device according to claim 4, characterized in that: The microwave source and the coaxial feed port are connected via a coaxial transmission line.

6. The large-area microwave plasma excitation device according to claim 1, characterized in that: The excitation members are in multiple groups with the same structure, and the number of the microwave sources is twice that of the excitation members.

7. The large-area microwave plasma excitation device according to claim 6, characterized in that: The distances between two adjacent groups of the excitation members are equal, and the axes of the multiple groups of the excitation members are in the same plane and parallel to the bottom of the excitation cavity.

8. The large-area microwave plasma excitation device according to claim 1, characterized in that: The excitation component divides the excitation chamber into an upper chamber and a lower chamber; when the gas inlet is connected to the upper chamber, the gas outlet is connected to the lower chamber; when the gas outlet is connected to the upper chamber, the gas inlet is connected to the lower chamber.

9. The large-area microwave plasma excitation device according to claim 1, characterized in that: The gap between the outer side surface of the non-uniform coil and the outer glass tube is 0-1 mm.

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