Process gas distribution structure of flat plate type plasma system applied to peald equipment

Abstract

The invention provides a process gas distribution structure of a flat plate type plasma system applied to peald equipment, and relates to the technical field of plasma equipment. Comprising a vacuum cavity, a medium flat plate, an atmosphere side process pipeline and a vacuum side process pipeline, and the vacuum side process pipeline comprises a plurality of process gas pipe branches parallel to the medium flat plate so that ionized gas can be evenly distributed in the vacuum cavity; a plurality of gas holes with openings facing the medium window are uniformly distributed in each process gas pipe branch along the length direction of the process gas pipe branch, so that gas directly flows to the medium window after coming out of the process gas pipe branch, and continuously flows to the vacuum cavity after being rebounded by the medium window, and a gas rebounding area is just positioned in a high ionization area of plasma; and the ionization rate of the process gas is further improved. According to the scheme, the plasma distribution uniformity of the flat plate type plasma system can be improved.

Description

Technical Field

[0001] The present invention relates to the technical field of plasma equipment, and in particular to a process gas distribution structure of a flat-plate plasma system applied to a peald equipment. Background Art

[0002] There are two main types of process gas supply systems currently used in batch peald equipment plasma systems: one is a back-plate multi-layer split flow uniform gas distribution system; the other is a ring-shaped uniform flow gas distribution system. The back-plate multi-layer split flow uniform distribution intake system has a relatively complex structure. Generally, a double-layer or three-layer uniform flow method is used to obtain uniform intake of the entire surface. The disassembly and maintenance of parts is relatively difficult. The maintenance cost is high. Due to the problem of coil layout, the back-plate multi-layer split flow intake system is mostly used in plasma systems where the RF coil is spirally distributed on the side wall of the plasma chamber, because this type of plasma system has no requirements for the back plate material and can be made by metal processing. Since the RF coil of the flat-plate plasma system is mainly distributed on the atmospheric side of the back plate of the plasma chamber. The requirement for the back plate material must be a dielectric material so that the radio frequency wave can be coupled into the vacuum chamber. Therefore, for the flat-plate plasma system, this process gas supply system cannot be applied due to material properties. The ring-shaped uniform flow distribution system is also another common uniform gas distribution method. This intake method is annularly distributed around the back plate because the airflow is close to the inner wall of the vacuum chamber. The airflow will converge toward the center of the vacuum chamber, and the distribution of ionized gas on the inner wall of the vacuum chamber is uneven. Summary of the invention

[0003] The invention discloses a process gas distribution structure of a flat-plate plasma system of a peald device, aiming to solve the problem of uneven distribution and low efficiency of plasma generated by the flat-plate plasma system.

[0004] The present invention adopts the following scheme:

[0005] A process gas distribution structure for a flat-plate plasma system of a peald device, comprising:

[0006] a vacuum chamber, wherein the vacuum chamber is provided with a plasma outlet facing the substrate;

[0007] a dielectric plate, which is arranged on a side of the vacuum chamber away from the substrate and facing the substrate, and is used to couple radio frequency waves into the vacuum chamber, and a plurality of dielectric windows are arranged on the dielectric plate;

[0008] an atmosphere-side process pipeline, wherein the atmosphere-side process pipeline is formed with at least two gas inlet branches for introducing process gas into the vacuum chamber;

[0009] A vacuum side process pipeline is arranged inside the vacuum chamber and connected to the atmosphere side process pipeline; the vacuum side process pipeline includes a plurality of process gas pipe branches parallel to the medium plate so that the ionized gas is evenly distributed in the vacuum chamber; each process gas pipe branch is evenly distributed with a plurality of air holes opening toward the medium window along its length direction, so that the gas flows directly to the medium window after coming out of the process gas pipe branch, and continues to flow to the vacuum chamber after rebounding through the medium window, so that the gas rebound area is just in the high ionization area of ​​the plasma, thereby improving the ionization rate of the process gas.

[0010] Furthermore, cavity flanges are provided at both upper and lower ends of the vacuum cavity, and two atmosphere-side process pipelines are provided and respectively connected to the upper and lower cavity flanges for introducing process gas into the vacuum-side process pipelines.

[0011] Furthermore, each atmosphere-side process pipeline is provided with two of the air intake branches, and each of the air intake branches is connected to a process air pipe branch.

[0012] Furthermore, the air holes are arranged in a vertical row on the process air pipe branch, and at least two vertical rows of air holes are provided.

[0013] Furthermore, the diameter of the pores on the process gas pipe branch is 0.1 mm to 3 mm.

[0014] Furthermore, the plurality of process gas pipe branches are located in the same plane, and the plane is parallel to the plane where the medium plate is located.

[0015] Furthermore, a plurality of the process gas pipe branches are distributed in the vacuum chamber at equal intervals.

[0016] Furthermore, each of the process gas pipe branches is provided with a notch positioning structure to facilitate quick installation.

[0017] Beneficial effects:

[0018] In this solution, due to the characteristics of the flat-plate plasma distribution, the gas distribution system of this application is more suitable for this type of plasma device. After the gas is branched out from the process gas pipe, it flows to the medium window, and after rebounding through the medium window, it continues to flow to the vacuum chamber. The gas rebound area is just in the high ionization area of ​​the plasma, the gas is more easily ionized, and the gas ionization rate will be higher. In this rebound process, the uniform distribution of the gas will become better, especially for the gas close to the inner wall of the plasma chamber, and the entire gas pipeline is easier to maintain and relatively easy to dismantle. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1It is a schematic structural diagram of a process gas distribution structure of a flat-plate plasma system applied to a peald device according to an embodiment of the present invention;

[0020] Figure 2 This is a schematic diagram of the distribution of process pipelines on the atmosphere side of a process gas distribution structure of a flat-plate plasma system applied to a peald device according to an embodiment of the present invention;

[0021] Figure 3 It is a side schematic diagram of the distribution of process pipelines on the atmosphere side of a process gas distribution structure of a flat-plate plasma system applied to a peald device according to an embodiment of the present invention;

[0022] Figure 4 This is a schematic diagram of the distribution of process gas pipes in a process gas distribution structure of a flat-plate plasma system applied to a peald device according to an embodiment of the present invention;

[0023] Figure 5 It is a structural schematic diagram of a process gas pipe branch of a process gas distribution structure of a flat-plate plasma system applied to a peald device according to an embodiment of the present invention;

[0024] Icons: vacuum chamber 1, dielectric plate 2, dielectric window 21, atmosphere side process pipeline 3, air inlet branch 31, vacuum side process pipeline 4, process gas pipe branch 41, air hole 411, notch positioning structure 412, RF coil 5, grid plate 6, chamber flange 7. DETAILED DESCRIPTION

[0025] Combination Figures 1 to 5 As shown, this embodiment provides a process gas distribution structure of a flat-plate plasma system applied to a peald device, including:

[0026] A vacuum chamber 1, wherein the vacuum chamber 1 is provided with a plasma outlet facing the substrate;

[0027] a dielectric plate 2, which is disposed on a side of the vacuum chamber away from the substrate and facing the substrate, and is used to couple radio frequency waves into the vacuum chamber, and a plurality of dielectric windows 21 are disposed on the dielectric plate 2;

[0028] An atmosphere-side process pipeline 3, wherein the atmosphere-side process pipeline 3 is formed with at least two gas inlet branches 31 for introducing process gas into the vacuum chamber;

[0029] A vacuum side process pipeline 4, the vacuum side process pipeline 4 is arranged inside the vacuum chamber 1 and connected to the atmosphere side process pipeline 3; the vacuum side process pipeline 4 includes a plurality of process gas pipe branches 41 parallel to the medium plate 2 to evenly distribute the ionized gas in the vacuum chamber 1; each of the process gas pipe branches 41 is evenly distributed along its length with a plurality of air holes 411 opening toward the medium window 21, so that the gas flows directly to the medium window 21 after coming out of the process gas pipe branch 41, and continues to flow to the vacuum chamber 1 after rebounding from the medium window 21, so that the gas rebound area is just in the high ionization area of ​​the plasma, thereby improving the ionization rate of the process gas.

[0030] Combination Figure 1 As shown, in this embodiment, the flat-plate plasma system further includes a vacuum chamber, an RF coil 5, a dielectric plate 2 and a grid plate 6; wherein the dielectric plate 2 is arranged outside the vacuum chamber and facing the substrate, and is provided with a dielectric window 21 for coupling radio frequency waves into the vacuum chamber; the grid plate 6 is arranged on the other side of the vacuum chamber opposite to the dielectric window 21, and is used to control the bombardment density of the plasma on the substrate to reduce the temperature rise of the substrate; the air inlet pipeline extends into the vacuum chamber to provide the reaction gas to the vacuum chamber; the RF coil 5 is suitable for providing an excitation electromagnetic field to the vacuum chamber under the drive of the radio frequency power supply to ionize the reaction gas to form plasma, and the RF coil 5 is installed in a flat structure on the side of the dielectric plate away from the vacuum chamber, so that the plasma is evenly distributed on the dielectric plate 2 facing the substrate. The distance between the dielectric plate 2 and the grid plate 6 is 40 mm to 200 mm. At this distance, the plasma source and the substrate are relatively closer, the transmission efficiency of the plasma is higher, and the power input to the plasma generator to achieve the same film performance can be relatively lower. The RF coil 5 is connected to a radio frequency power supply, which is arranged on the outside of the dielectric plate 2. The RF coil 5 is laid on the surface of the dielectric plate 2 in a flat shape, or embedded in the dielectric plate 2, and the entire RF coil 5 is arranged in a spiral centrosymmetric structure. On the one hand, it can increase the inductance range, and on the other hand, it can make the generated plasma distribution more uniform and concentrated, which is convenient for improving the uniformity of the plasma. The RF coil 5 is concentrated on the plane of the dielectric plate 2 and presents a spiral and centrosymmetric structure.

[0031] Combination Figures 1 to 4As shown, chamber flanges 7 are provided at both ends of the vacuum chamber 1, and two atmosphere-side process pipelines 3 are provided, and are respectively connected to the upper and lower chamber flanges 7 for introducing process gas into the vacuum-side process pipeline 4. In this embodiment, each atmosphere-side process pipeline 3 is provided with two inlet branches 31, and each inlet branch 31 is connected to a process gas pipe branch 41. Thus, four process gas pipe branches 41 are arranged in parallel in the vacuum chamber. It should be noted that the structure of the atmosphere-side process pipeline 3 is mainly designed based on the principle of binary gas separation, and the vacuum-side process pipeline 4 adopts four process gas pipe branches 41, but it is not limited to this, and two process gas pipe branches 41 or eight process gas pipe branches 41 can also be used. The multiple process gas pipe branches 41 are located in the same plane, and the plane is parallel to the plane where the medium plate 2 is located. This setting can make the process gas introduced from the process gas pipe branch 41 have the same distance from the medium window 21 on the medium plate 2 to ensure the uniformity of the ionized gas. Furthermore, the plurality of process gas pipe branches 41 are evenly spaced and distributed in the vacuum chamber 1 , so as to further improve the uniformity of the process gas after being introduced into the vacuum chamber 1 .

[0032] Combination Figure 5 As shown, in a preferred embodiment, a notch positioning structure 412 is provided at the end of the process gas pipe branch 41, so that a plurality of process gas pipe branches 41 can be combined into a longer process gas pipe, and it is convenient for quick installation. However, the direction and repeatability positioning are not limited to this method, and the positioning can be performed by means of pins and the like.

[0033] Each of the process gas pipe branches 41 is arranged with air holes 411 opening toward the medium window 21, and the air holes 411 are evenly distributed along the length direction of the process gas pipe branch 41 to form a longitudinal arrangement, and at least two longitudinal rows of air holes 411 are arranged on each of the process gas pipe branches 41, so that the process gas can be introduced in a wider range and with a higher gas density. The aperture of the air holes 411 on the process gas pipe branch is 0.1 mm to 3 mm, preferably 0.1 mm. Since the diameter of the process gas pipe branch 41 is small, the aperture of the air holes 411 is also relatively small, and the gas flow rate ejected from the smaller aperture is greater, so that it can flow to the medium window 21 at a faster speed, and continue to flow to the vacuum chamber 1 after rebounding from the medium window 21, and the rebound speed is also faster; the gas rebound area is just in the high ionization area of ​​the plasma, and the gas is more easily ionized, and the gas ionization rate will be higher. In this rebound process, the uniform distribution of the process gas will become better, especially for the gas close to the inner wall of the plasma chamber.

[0034] In this solution, due to the characteristics of the flat-plate plasma distribution, the gas distribution system of the present application is more suitable for this type of plasma device. After the gas comes out of the process gas pipe branch 41, it flows to the medium window 21, and continues to flow to the vacuum chamber 1 after rebounding through the medium window 21. The gas rebound area is just in the high ionization area of ​​the plasma, the gas is more easily ionized, and the gas ionization rate will be higher. In this rebound process, the uniform distribution of the gas will become better, especially for the gas that is only around the inner wall of the plasma chamber, and the entire gas pipeline is easier to maintain and relatively easy to dismantle.

[0035] The gas distribution structure of the embodiment is more suitable for a flat-plate plasma generating system, and can effectively improve the uniformity of plasma concentration in the flat-plate plasma generating system, thereby helping to improve the uniformity of substrate reaction.

[0036] It should be understood that the above are only preferred implementations of the present invention, and the protection scope of the present invention is not limited to the above embodiments. All technical solutions under the concept of the present invention belong to the protection scope of the present invention.

[0037] The above description of the drawings used in the implementation manner only illustrates certain embodiments of the present invention and should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without paying creative work.

Claims

1. A process gas distribution structure for a flat-plate plasma system used in a peald device, characterized in that: include: a vacuum chamber, wherein the vacuum chamber is provided with a plasma outlet facing the substrate; a dielectric plate, which is arranged on a side of the vacuum chamber away from the substrate and facing the substrate, and is used to couple radio frequency waves into the vacuum chamber, and a plurality of dielectric windows are arranged on the dielectric plate; an atmosphere-side process pipeline, wherein the atmosphere-side process pipeline is formed with at least two gas inlet branches for introducing process gas into the vacuum chamber; A vacuum side process pipeline is arranged inside the vacuum chamber and connected to the atmosphere side process pipeline; the vacuum side process pipeline includes a plurality of process gas pipe branches parallel to the medium plate so that the ionized gas is evenly distributed in the vacuum chamber; each process gas pipe branch is evenly distributed with a plurality of air holes opening toward the medium window along its length direction, so that the gas flows directly to the medium window after coming out of the process gas pipe branch, and continues to flow to the vacuum chamber after rebounding through the medium window, so that the gas rebound area is just in the high ionization area of ​​the plasma, thereby improving the ionization rate of the process gas.

2. The process gas distribution structure of the flat-plate plasma system applied to the peald equipment according to claim 1, characterized in that: The upper and lower ends of the vacuum cavity are both provided with cavity flanges, and two atmosphere-side process pipelines are provided and respectively connected to the upper and lower cavity flanges for introducing process gas into the vacuum-side process pipelines.

3. The process gas distribution structure of the flat-plate plasma system applied to the peald equipment according to claim 2, characterized in that: Each atmosphere-side process pipeline is provided with two air inlet branches, and each of the air inlet branches is connected to a process air pipe branch.

4. The process gas distribution structure of the flat-plate plasma system applied to the peald equipment according to claim 1, characterized in that: The air holes are arranged in a vertical row on the process air pipe branch, and at least two vertical rows of air holes are provided.

5. The process gas distribution structure of the flat-plate plasma system applied to the peald equipment according to claim 4, characterized in that: The diameter of the air holes on the process air pipe branch is 0.1mm to 3mm.

6. The process gas distribution structure of the flat-plate plasma system applied to the peald equipment according to claim 1, characterized in that: The plurality of process gas pipe branches are located in the same plane, and the plane is parallel to the plane where the medium plate is located.

7. The process gas distribution structure of the flat-plate plasma system applied to the peald equipment according to claim 6, characterized in that: The plurality of process gas pipe branches are distributed in the vacuum chamber at equal intervals.

8. The process gas distribution structure of the flat-plate plasma system applied to the peald equipment according to claim 1, characterized in that: Each of the process gas pipe branches is provided with a notch positioning structure to facilitate quick installation.

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