Process gas distribution structure for flat panel plasma system applied to peald apparatus

Abstract

The application provides a process gas distribution structure of a flat plate type plasma system applied to a PEALD device, and relates to the technical field of plasma devices. The process gas distribution structure comprises a vacuum cavity, a dielectric flat plate, an atmospheric side process pipeline and a vacuum side process pipeline. The vacuum side process pipeline comprises a plurality of process gas pipe branches parallel to the dielectric flat plate, so that ionized gas is uniformly distributed in the vacuum cavity. Each process gas pipe branch is uniformly provided with a plurality of gas holes with openings facing the dielectric window along the length direction of the process gas pipe branch, so that the gas directly flows to the dielectric window after being discharged from the process gas pipe branch, and continues to flow to the vacuum cavity after being bounced back through the dielectric window. The gas bouncing area is just in the high ionization area of the plasma, thereby improving the ionization rate of the process gas. The plasma distribution uniformity of the flat plate type plasma system can be improved through the scheme.

Description

Technical Field

[0001] This invention relates to the field of plasma equipment technology, and more specifically, to a process gas distribution structure for a flat-plate plasma system applied to a peald device. Background Technology

[0002] There are two main types of process gas supply systems used in batch PELAND plasma systems: a backplate-type multi-layer split-flow uniform gas distribution system and a ring-shaped uniform flow gas distribution system. The backplate-type multi-layer split-flow uniform gas distribution system has a relatively complex structure, generally employing a double- or triple-layer flow distribution method to achieve uniform gas intake across the entire surface. Disassembly and maintenance of components are more difficult, resulting in higher maintenance costs. Due to coil layout issues, the backplate-type multi-layer split-flow gas distribution system is mostly used in plasma systems where the RF coils are spirally distributed on the sidewalls of the plasma cavity. This type of plasma system has no requirements for the backplate material and can be made of metal. However, in planar plasma systems, the RF coils are mainly distributed on the atmospheric side of the backplate of the plasma cavity. The backplate material must be a dielectric material so that the radio frequency waves can couple into the vacuum cavity. Therefore, this process gas supply system cannot be applied to planar plasma systems due to material properties. The ring-shaped uniform flow distribution system is another common method of uniform gas distribution. In this method, the airflow is distributed in a ring around the backplate, close to the inner wall of the vacuum cavity. The airflow converges towards 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] This invention discloses a process gas distribution structure for a planar plasma system of a Peald device, aiming to solve the problems of uneven plasma distribution and low efficiency generated by the planar plasma system.

[0004] The present invention adopts the following solution:

[0005] A process gas distribution structure for a flat-plate plasma system used in a PEARL device, comprising:

[0006] A vacuum chamber having a plasma outlet facing the substrate;

[0007] A dielectric plate is disposed on the side of the vacuum cavity away from the substrate and facing the substrate, for coupling radio frequency waves into the vacuum cavity, and multiple dielectric windows are provided on the dielectric plate.

[0008] An atmospheric side process pipeline, wherein the atmospheric side process pipeline forms at least two inlet branches to introduce process gas into the vacuum chamber;

[0009] A vacuum side process pipeline is arranged inside the vacuum cavity and is communicated with the atmospheric side process pipeline; the vacuum side process pipeline comprises a plurality of process gas sub-pipelines parallel to the medium plate to uniformly distribute the ionized gas in the vacuum cavity; each process gas sub-pipeline is uniformly provided with a plurality of gas holes with openings facing the medium window along the length direction of the process gas sub-pipeline, so that the gas flows directly to the medium window after being discharged from the process gas sub-pipeline, and continues to flow to the vacuum cavity after being bounced off the medium window, so that the gas bouncing area is just in the high ionization area of the plasma, thereby improving the ionization rate of the process gas.

[0010] Further, the upper and lower ends of the vacuum cavity are both provided with cavity flanges, the atmospheric side process pipeline is provided with two and is connected to the upper and lower cavity flanges respectively to guide the process gas into the vacuum side process pipeline.

[0011] Further, each atmospheric side process pipeline is provided with two gas inlet sub-pipelines, and each gas inlet sub-pipeline is connected with a process gas sub-pipeline.

[0012] Further, the gas holes are arranged in longitudinal columns on the process gas sub-pipeline, and at least two longitudinal columns of gas holes are provided.

[0013] Further, the diameter of the gas holes on the process gas sub-pipeline is 0.1mm-3mm.

[0014] Further, a plurality of process gas sub-pipelines are located in the same plane, and the plane is parallel to the plane where the medium plate is located.

[0015] Further, a plurality of process gas sub-pipelines are distributed at equal intervals in the vacuum cavity.

[0016] Further, each process gas sub-pipeline is provided with a notch positioning structure to facilitate quick installation.

[0017] Beneficial effects:

[0018] In the scheme, due to the characteristics of the flat plate type plasma distribution, the gas distribution system of the application is more suitable for this type of plasma device. After the gas is discharged from the process gas sub-pipeline, it flows to the medium window, and continues to flow to the vacuum cavity after being bounced off the medium window. The gas bouncing area is just in the high ionization area of the plasma, so the gas is more easily ionized, and the ionization rate of the gas is higher. The uniform distribution of the gas becomes better in this bouncing process, especially for the gas close to the inner wall of the plasma cavity, and the entire gas pipeline is easier to maintain and relatively easy to remove. BRIEF DESCRIPTION OF DRAWINGS

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

[0020] Figure 2 is a distribution schematic diagram of an atmospheric side process pipeline of a process gas distribution structure of a flat plate type plasma system applied to a PEALD device according to an embodiment of the present application;

[0021] Figure 3 is a side view schematic diagram of a distribution of an atmospheric side process pipeline of a process gas distribution structure of a flat plate type plasma system applied to a PEALD device according to an embodiment of the present application;

[0022] Figure 4 is a distribution schematic diagram of a process gas pipeline of a process gas distribution structure of a flat plate type plasma system applied to a PEALD device according to an embodiment of the present application;

[0023] Figure 5 is a structural schematic diagram of a process gas pipeline of a process gas distribution structure of a flat plate type plasma system applied to a PEALD device according to an embodiment of the present application;

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

[0025] In combination Figures 1 to 5 As shown in the drawings, the embodiment provides a process gas distribution structure of a flat plate type plasma system applied to a PEALD device, which comprises:

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

[0027] A dielectric plate 2, which is arranged on the side of the vacuum cavity away from the substrate and opposite to the substrate position, for coupling RF waves into the vacuum cavity, and a plurality of dielectric windows 21 are arranged on the dielectric plate 2;

[0028] An atmospheric side process pipeline 3, which is formed with at least two gas inlet branches 31 to guide process gas into the vacuum cavity;

[0029] A vacuum side process pipeline 4 is arranged inside the vacuum cavity 1 and communicates with the atmospheric side process pipeline 3; the vacuum side process pipeline 4 includes a plurality of process gas sub-pipes 41 parallel to the dielectric plate 2 to make the ionized gas uniformly distributed in the vacuum cavity 1; each of the process gas sub-pipes 41 is uniformly provided with a plurality of gas holes 411 with openings facing the dielectric window 21 along the length direction of the process gas sub-pipe 41, so that the gas flows directly to the dielectric window 21 after coming out of the process gas sub-pipe 41, and continues to flow to the vacuum cavity 1 after being bounced off the dielectric window 21, so that the gas bouncing area is just in the high ionization area of the plasma, thereby improving the ionization rate of the process gas.

[0030] In combination Figure 1 As shown in the embodiment, the flat plate type plasma system further includes a vacuum cavity, an RF coil 5, a dielectric plate 2 and a grid plate 6; wherein the dielectric plate 2 is arranged outside the vacuum cavity and faces the substrate position, and is provided with a dielectric window 21 for coupling radio frequency waves into the vacuum cavity; the grid plate 6 is arranged on the vacuum cavity and on the side opposite to the dielectric window 21, for controlling the bombardment density of the plasma on the substrate to reduce the temperature rise of the substrate; the gas inlet pipeline extends into the vacuum cavity to provide the reaction gas to the vacuum cavity; the RF coil 5 is adapted to provide an excitation electromagnetic field to the vacuum cavity under the driving of a radio frequency power source to make the reaction gas ionized to form plasma, and the RF coil 5 is installed in a flat plate type structure on the side of the dielectric plate away from the vacuum cavity, so that the plasma is uniformly distributed on the dielectric plate 2 facing the substrate. The distance between the dielectric plate 2 and the grid plate 6 is 40mm-200mm, under which the plasma source and the substrate position are relatively closer, the transmission efficiency of the plasma is higher, and the input power of the plasma generating device to achieve the same film layer performance can be relatively low. The RF coil 5 is connected with a radio frequency power source, which is arranged outside the dielectric plate 2, and the RF coil 5 is laid in a flat plate type on the surface of the dielectric plate 2, or inlaid into the dielectric plate 2, and the whole RF coil 5 is arranged in a spiral type central symmetric structure, which can improve the inductance range on the one hand, and make the generated plasma more uniformly and concentrated, thereby improving the uniformity of the plasma. The RF coil 5 is concentrated on the dielectric plate 2 plane in a spiral and central symmetric structure.

[0031] In combination Figures 1 to 4As shown, the upper and lower ends of the vacuum cavity 1 are provided with cavity flanges 7, the atmospheric side process pipeline 3 is provided with two, and is connected to the upper and lower cavity flanges 7 respectively to guide the process gas into the vacuum side process pipeline 4. In the embodiment, each atmospheric side process pipeline 3 is provided with two gas inlet branches 31, and each gas inlet branch 31 is connected with a process gas pipe branch 41. Thus, four process gas pipe branches 41 are arranged in parallel in the vacuum cavity. It should be noted that the atmospheric side process pipeline 3 is mainly designed according to the principle of binary gas distribution, and the vacuum side process pipeline 4 is provided with four process gas pipe branches 41, but is not limited to this, and can also be provided with two process gas pipe branches 41 or eight process gas pipe branches 41, etc. The plurality of process gas pipe branches 41 are located in the same plane, and the plane is parallel to the plane where the dielectric plate 2 is located. This arrangement can make the process gas guided from the process gas pipe branch 41 have the same distance to the dielectric window 21 on the dielectric plate 2, so as to ensure the uniformity of the ionized gas. Further, the plurality of process gas pipe branches 41 are distributed at equal intervals in the vacuum cavity 1, so as to further improve the uniformity of the process gas guided into the vacuum cavity 1.

[0032] In combination Figure 5 As shown, in the preferred embodiment, the end of the process gas pipe branch 41 is provided with a notch positioning structure 412, so that a plurality of process gas pipe branches 41 can be combined into a longer process gas pipe, and quick installation is facilitated. However, this is not the only way to position the direction and repeatability, and other positioning methods such as pin clamping can also be used.

[0033] The gas hole 411 with an opening facing the dielectric window 21 is arranged on each process gas pipe branch 41, and the gas holes 411 are uniformly distributed along the length direction of the process gas pipe branch 41 to form a vertical arrangement. At least two vertical rows of gas holes 411 are arranged on each process gas pipe branch 41, so that the range of process gas guided is larger and the gas density is larger. The diameter of the gas hole 411 on the process gas pipe branch is 0.1mm-3mm, and preferably 0.1mm. Since the pipe diameter of the process gas pipe branch 41 is small, the diameter of the gas hole 411 is also relatively small. The gas flow rate ejected by the smaller diameter is larger, so that the gas can flow to the dielectric window 21 at a faster speed, and after rebounding through the dielectric window 21, the gas continues to flow to the vacuum cavity 1, and the rebounding speed is also faster. The gas rebounding area is just in the high ionization area of the plasma, so the gas is more easily ionized, and the ionization rate of the gas is higher. In this rebounding process, the uniform distribution of the process gas becomes better, especially for the gas close to the inner wall of the plasma cavity.

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

[0035] Through the gas distribution structure of the present embodiment scheme, it is more suitable for the flat plate type plasma generation system, which can effectively improve the uniformity of the plasma concentration of the flat plate type plasma generation system, thereby helping to improve the uniformity of the substrate reaction.

[0036] It should be understood that: the above is only the preferred embodiment of the present application, the protection scope of the present application is not limited to the above-mentioned embodiments, any technical scheme that belongs to the idea of the present application is within the protection scope of the present application.

[0037] The above description of the drawings used in the embodiments only shows some embodiments of the present application, and should not be considered as limiting the scope. For those skilled in the art, other related drawings can be obtained from these drawings without creative labor.

Claims

1. A process gas distribution structure for a flat-plate plasma system applied to a PEARL device, characterized in that, include: A vacuum chamber having a plasma outlet facing the substrate; A dielectric plate is disposed on the side of the vacuum cavity away from the substrate and facing the substrate, for coupling radio frequency waves into the vacuum cavity, and multiple dielectric windows are provided on the dielectric plate. An atmospheric side process pipeline, wherein the atmospheric side process pipeline forms at least two inlet branches to introduce process gas into the vacuum chamber; A vacuum-side process pipeline is disposed inside the vacuum chamber and connected to the atmospheric-side process pipeline. The vacuum-side process pipeline includes multiple process gas branch lines parallel to the medium plate to ensure uniform distribution of ionized gas within the vacuum chamber. Each process gas branch line has multiple vents evenly distributed along its length, with openings facing the medium window. This allows gas to flow directly to the medium window after exiting the process gas branch line, and after rebounding through the medium window, continue flowing into the vacuum chamber. This ensures that the gas rebound area is precisely within the high ionization region of the plasma, thereby improving the ionization rate of the process gas. It also includes RF coils that are laid flat on the surface of a dielectric plate.

2. The process gas distribution structure for a flat-plate plasma system applied to a PEARL device according to claim 1, characterized in that, Both ends of the vacuum chamber are provided with chamber flanges. There are two atmospheric side process pipelines, which are respectively connected to the upper and lower chamber flanges to introduce process gas into the vacuum side process pipelines.

3. The process gas distribution structure for a flat-plate plasma system applied to a PEARL device according to claim 2, characterized in that, Each atmospheric side process pipeline is provided with two of the aforementioned air intake branches, and each of the aforementioned air intake branches is connected to a process gas pipeline branch.

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

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

6. The process gas distribution structure of the flat-plate plasma system applied to the PEARL equipment according to claim 1, characterized in that, Multiple process gas branch lines are located in the same plane, and this plane is parallel to the plane where the medium plate is located.

7. The process gas distribution structure for a flat-plate plasma system applied to a PEARL equipment according to claim 6, characterized in that, Multiple process gas pipes are distributed at equal intervals within the vacuum chamber.

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

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