ICP radio frequency antenna discharge protection ion source

Abstract

The invention provides an ICP radio frequency antenna discharge protection ion source which comprises an ion container, a quartz lining, a discharge electrode and a vacuumizing system. The ion container is provided with an internal space for generating plasma; the quartz lining is arranged in the ion container so as to divide the internal space of the ion container into a discharge cavity located on the inner side of the quartz lining and a clamping cavity located on the outer side of the quartz lining; the discharge electrode is arranged in the clamping cavity; the air exhaust system comprises two mutually independent air exhaust pipelines, one air exhaust pipeline is connected with the discharge cavity, and the other air exhaust pipeline is connected with the clamping cavity. According to the invention, the discharge electrode is separately placed in an isolated manner, and the space where the discharge electrode is located can be separately vacuumized, so that pollution generated by ion bombardment is isolated, and the service life of the discharge electrode is also prolonged.

Description

Technical Field

[0001] The present invention relates to the field of coating technology, and particularly to an ICP radio frequency antenna discharge protection ion source. Background Art

[0002] In most ion sources, the discharge electrode is located in the working area or in the same vacuum chamber. During the discharge process, the particles generated by ionizing the process gas bombard the electrode continuously while bombarding the target material. This will cause the electrode to heat up. More seriously, the continuous bombardment of ions on the electrode will cause electrode loss, thus severely shortening the maintenance cycle and usage cost of the equipment. At the same time, it will also cause contamination of coating or etching. Summary of the Invention

[0003] In order to solve the technical problems existing in the background art, the present invention provides an ICP radio frequency antenna discharge protection ion source.

[0004] An ICP radio frequency antenna discharge protection ion source provided by the present invention includes: an ion container, a quartz inner lining, a discharge electrode, and a vacuum pumping system;

[0005] The ion container has an internal space for generating plasma; the quartz inner lining is arranged inside the ion container to divide the internal space of the ion container into a discharge cavity inside the quartz inner lining and a clamping cavity outside the quartz inner lining; the discharge electrode is arranged in the clamping cavity; the pumping system includes two independent pumping pipelines, one of which is connected to the discharge cavity to maintain and obtain a vacuum condition in the discharge cavity; the other pumping pipeline is connected to the clamping cavity to maintain and obtain a vacuum condition in the clamping cavity.

[0006] Preferably, in the working state, the vacuum degree of the clamping cavity is higher than that of the discharge cavity.

[0007] Preferably, the discharge electrode has a hollow channel inside to pass a refrigerant medium.

[0008] Preferably, the material of the discharge electrode is oxygen-free copper, and its surface is silver-plated.

[0009] Preferably, the silver-plated surface of the discharge electrode is gold-plated.

[0010] Preferably, the quartz inner lining is arranged inside the ion container near its upper part and is arranged circumferentially along the inner wall of the ion container to form a clamping cavity between the inner wall of the ion container and the outer wall of the quartz inner lining; the discharge electrode is an annular structure arranged circumferentially along the inner wall of the ion container.

[0011] Preferably, an excitation coil is arranged on the outer wall of the ion container and outside the discharge electrode.

[0012] Preferably, the excitation coil is in the shape of an annular racetrack, and the discharge electrode is located inside the annular racetrack.

[0013] Preferably, the ion container is a container with a length direction, and there are two sets of exciting coils, which are oppositely arranged on the length surfaces on both sides of the ion container.

[0014] In the present invention, the internal space of the ion container is divided into a discharge chamber located inside the quartz inner liner and a clamping chamber located outside the quartz inner liner; the discharge electrode is arranged in the clamping chamber so that the discharge electrode is in a protection area independent of the discharge chamber. Then, two vacuum pumping pipelines are respectively connected to the discharge chamber and the clamping chamber so that the discharge chamber and the clamping chamber can be evacuated separately. In the initial stage of operation, the two vacuum pumping pipelines evacuate the discharge chamber and the clamping chamber respectively to minimize the impurity components such as air, organic substances, and water molecules in the space and reduce the discharge pollution. Before discharging, process gases such as Ar, O2, or N2 are introduced into the discharge chamber. At this time, the vacuum pressure inside the discharge chamber rises, while the internal space of the clamping chamber still maintains the original high vacuum. Then, the power supply is turned on, and the process gas inside the discharge chamber is excited by the radio frequency oscillation signal to generate plasma inside the discharge chamber. Since the internal vacuum degree of the clamping chamber is relatively high and there is no process gas, no plasma will be excited and generated. Therefore, the discharge electrode arranged inside the clamping chamber will not be bombarded by the plasma, thus isolating the pollution generated by ion bombardment and increasing the service life of the discharge electrode. Description of the Drawings

[0015] Figure 1 It is a schematic structural diagram of an ICP radio frequency antenna discharge protection ion source proposed by the present invention. Detailed Embodiments

[0016] Referring to Figure 1 , an ICP radio frequency antenna discharge protection ion source proposed by the present invention includes: an ion container 1, a quartz inner liner 2, a discharge electrode 3, and a vacuum pumping system;

[0017] The ion container 1 has an internal space for generating plasma. The quartz inner liner 2 is arranged inside the ion container 1 to divide the internal space of the ion container 1 into a discharge chamber a located inside the quartz inner liner 2 and a clamping chamber b located outside the quartz inner liner 2. Specifically: the quartz inner liner 2 is arranged inside the ion container 1 near its upper part and is arranged circumferentially along the inner wall of the ion container 1 to form a clamping chamber b between the inner wall of the ion container 1 and the outer wall of the quartz inner liner 2. The discharge electrode 3 is arranged in the clamping chamber b. Specifically: the discharge electrode 3 is an annular structure arranged circumferentially along the inner wall of the ion container 1. The air extraction system includes two independent air extraction pipelines 4 and 5. One air extraction pipeline 4 is connected to the discharge chamber a to maintain and obtain a vacuum condition for the discharge chamber a; the other air extraction pipeline 5 is connected to the clamping chamber b to maintain and obtain a vacuum condition for the clamping chamber b, and in the working state, the vacuum degree of the clamping chamber b is higher than that of the discharge chamber a. The working mode is as follows:

[0018] During operation, at the initial stage of operation, two vacuum lines are used to vacuum the discharge chamber and the clamp chamber b to 10E-6mBar respectively, so as to minimize the impurities such as air, organic matter, water molecules, etc. in the space and reduce discharge pollution. Before discharge, process gases such as Ar, O2 or N2 are introduced into the discharge chamber a (in specific operation, corresponding gases are used according to different processes), so that the vacuum pressure inside the discharge chamber a rises to about 10E-3mBar. At this time, since the corresponding process gas is not introduced into the clamp chamber b, the original 10E-6mBar high vacuum is still maintained inside the clamp chamber b. Then, the power is turned on, and the process gas introduced into the discharge chamber a is excited by the radio frequency oscillation signal, and plasma is generated inside the discharge chamber a. Since the clamp chamber b has a high internal vacuum degree and no process gas, it will not be excited to generate plasma, so the discharge electrode 3 arranged inside the clamp chamber b will not be bombarded by plasma.

[0019] In a further embodiment, the discharge electrode 3 has a hollow channel inside for passing a refrigerant. Since the discharge electrode 3 is placed in the clamping cavity b, the vacuum degree is very high during operation, and the vacuum cannot transfer heat. The discharge electrode 3 is made of a conductive material and can transmit radio frequency power by itself. At the same time, the hollow channel inside is used to circulate the refrigerant, so that the heat is also transferred through the refrigerant during discharge, ensuring that the temperature of the discharge electrode 3 is constant. While ensuring the continuity of discharge, the life of the discharge electrode 3 is greatly increased, and the radio frequency discharge power of the device can be increased to 12-15KW.

[0020] The material of the discharge electrode 3 is oxygen-free copper, and the surface is silver-plated, so that the resistance of the discharge electrode 3 is very small, ensuring low loss of radio frequency transmission. Then the silver-plated surface is gold-plated, so that the discharge electrode 3 can be stable in a high temperature environment and extreme discharge.

[0021] In addition, in this embodiment, an excitation coil 6 is arranged on the outer wall of the ion container 1 and outside the discharge electrode 3 to guide the plasma downward, make the plasma distribution more uniform, ensure the uniform deposition of the coating material on the substrate surface, and improve the film quality.

[0022] In a further embodiment, the excitation coil 6 is a ring track structure, and the discharge electrode 3 is located inside the ring track. The ring track coil generates a uniform and symmetrical magnetic field in the central area, and the discharge electrode 3 is located inside the ring track, in the area with the strongest magnetic field. The magnetic field can effectively confine the plasma, reduce the contact between the plasma and the container wall, and reduce energy loss and container damage. At the same time, the synergistic effect of the magnetic field and the discharge electrode 3 can guide the arc path, stabilize the discharge process, extend the life of the discharge electrode 3 and improve the discharge efficiency.

[0023] Specifically: The ion container 1 is a container with a length direction. There are two sets of exciting coils 6, which are oppositely arranged on the length surfaces on both sides of the ion container 1. This structural design can, on the one hand, generate a uniform magnetic field inside the ion container 1, covering the entire length direction to ensure the stable confinement of the plasma over a long distance; on the other hand, the symmetric arrangement of the two sets of coils can reduce the attenuation of the magnetic field at the edges of the ion container 1 to ensure that the plasma can also be effectively confined at both ends of the ion container 1. In addition, by independently adjusting the currents of the two sets of coils, the magnetic field intensity and distribution can be flexibly controlled to meet different experimental or process requirements.

[0024] As can be seen from the above, in the present invention, the discharge electrode 3 is separately isolated and placed, and the space where it is located can be separately evacuated, thereby isolating the contamination generated by ion bombardment and increasing the service life of the discharge electrode 3.

[0025] The above is only a preferred specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art within the technical scope disclosed by the present invention, according to the technical solution and inventive concept of the present invention, making equivalent substitutions or changes should be covered within the protection scope of the present invention.

Claims

1. An ICP radio frequency antenna discharge protection ion source, characterized in that, Comprising: An ion container (1), a quartz inner liner (2), a discharge electrode (3), and a vacuum pumping system; The ion container (1) has an internal space for generating plasma; the quartz inner liner (2) is disposed inside the ion container (1) to divide the internal space of the ion container (1) into a discharge chamber (a) inside the quartz inner liner (2) and a clamping chamber (b) outside the quartz inner liner (2); the discharge electrode (3) is disposed in the clamping chamber (b); the pumping system includes two independent pumping pipelines (4, 5), one of the pumping pipelines (4) is connected to the discharge chamber (a) to maintain and obtain a vacuum condition in the discharge chamber (a); the other pumping pipeline (5) is connected to the clamping chamber (b) to maintain and obtain a vacuum condition in the clamping chamber (b).

2. The ICP radio frequency antenna discharge protection ion source according to claim 1, characterized in that Under the working state, the vacuum degree of the clamping chamber (b) is higher than that of the discharge chamber (a).

3. The ICP radio frequency antenna discharge protection ion source according to claim 1, wherein The discharge electrode (3) has a hollow channel inside for passing a refrigerant medium.

4. The ICP radio frequency antenna discharge protection ion source according to claim 1, characterized in that The material of the discharge electrode (3) is oxygen-free copper, and its surface is silver-plated.

5. The ICP radio frequency antenna discharge protection ion source according to claim 4, characterized in that, The silver-plated surface of the discharge electrode (3) is gold-plated.

6. The ICP radio frequency antenna discharge protection ion source according to any one of claims 1-5, characterized in that, The quartz inner liner (2) is disposed inside the ion container (1) near its upper part and is disposed circumferentially along the inner wall of the ion container (1) to form a clamping chamber (b) between the inner wall of the ion container (1) and the outer wall of the quartz inner liner (2); the discharge electrode (3) is a ring structure disposed circumferentially along the inner wall of the ion container (1).

7. The ICP radio frequency antenna discharge protection ion source according to claim 1, characterized in that An excitation coil (6) is provided outside the outer wall of the ion container (1) and outside the discharge electrode (3).

8. The ICP radio frequency antenna discharge protection ion source according to claim 7, characterized in that, The excitation coil (6) is in a ring runway structure, and the discharge electrode (3) is located inside the ring runway.

9. The ICP radio frequency antenna discharge protection ion source according to any one of claims 7-8, characterized in that, The ion container (1) is a container with a length direction, and two sets of excitation coils (6) are provided. The two sets of excitation coils (6) are oppositely disposed on the length surfaces on both sides of the ion container (1).

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