Deposition system capable of realizing CVD (chemical vapor deposition) process and ALD (atomic layer deposition) process and deposition process

Abstract

The invention provides a deposition system capable of realizing a CVD (chemical vapor deposition) process and an ALD (atomic layer deposition) process and a deposition process, and relates to the technical field of semiconductor processing equipment. Comprising a high-temperature-resistant conical process tank suitable for storing powder, and further comprises a vacuum system connected to the upper portion of the conical process tank and an air source system connected to the lower portion of the conical process tank. The gas source system comprises a process gas path, a precursor gas path and a carrier gas path which are connected into the conical process tank; a plurality of valves are arranged in the air source system and used for switching and controlling an air path communicated with the conical process tank, and a spiral stirring mechanism suitable for lifting and stirring powder upwards from the conical bottom is arranged in the conical process tank; and after silicon is deposited on the powder, a CVD (chemical vapor deposition) process or an ALD (atomic layer deposition) process is selected to continue by controlling a valve of a gas source system. Through the scheme, the combination of the CVD process and the ALD process is realized, and a richer coating scheme is provided.

Description

Technical Field

[0001] The present invention relates to the technical field of semiconductor processing equipment, and in particular to a deposition system and process thereof capable of implementing a CVD process and an ALD process. Background Art

[0002] The existing solutions for realizing silicon-carbon deposition of titanium nitride, anode material, mainly include fluidized bed solution and rotary kiln solution. The fluidized bed solution uses airflow to suspend the powder material in the reaction vessel, so that it can fully contact and react with the gas phase or liquid phase, thereby realizing silicon-carbon deposition; while the rotary kiln solution is to load the powder in the rotary kiln, slowly rotate the furnace and introduce gas into the furnace for contact and reaction, thereby realizing silicon-carbon deposition. However, in the fluidized bed solution, it is generally realized in a slightly positive pressure environment, and the powder is lifted by the airflow to realize the full reaction between the gas and the powder. However, the air intake is relatively large, and the diameter of the bed cannot be increased due to the limitation of the fluidization effect. The fluidization height can only be increased, which makes it difficult to realize the capacity increase of a single cavity and a single batch, and it is difficult to realize industrial mass production. For the rotary kiln solution, it is difficult for the powder to fully contact with the gas, and the process time is long, and the process effect is worse than that of the fluidized bed.

[0003] At present, the CVD process and the high-temperature ALD process are designed separately. This is because the titanium nitride process needs to be implemented at high temperature, and the conventional ALD process is generally carried out in a low temperature (within 400°C) environment. Therefore, the conventional ALD system cannot perform the titanium nitride process. If the CAD process and the high-temperature ALD process are to be implemented on titanium nitride, two sets of equipment are required to complete it, but this may cause pollution during the logistics transfer process, and the process efficiency is also relatively low. Summary of the invention

[0004] The present invention discloses a deposition system capable of implementing a CVD process and an ALD process to solve the above-mentioned problems.

[0005] The present invention adopts the following scheme:

[0006] A deposition system capable of implementing a CVD process and an ALD process comprises a high temperature resistant conical process tank suitable for storing powders, a vacuum system connected above the conical process tank, and a gas source system connected below the conical process tank; wherein:

[0007] The gas source system includes a plurality of process gas circuits, a precursor gas circuit, and a carrier gas circuit connected to the conical process tank; a plurality of control valves are provided in the gas source system for switching and controlling the gas circuits connected to the conical process tank;

[0008] A spiral stirring mechanism is provided in the conical process tank, and the spiral stirring mechanism is suitable for lifting the powder upward from the bottom of the cone for stirring;

[0009] After silicon is deposited on the powder, the control valve of the gas source system is controlled to select whether to continue the CVD process or the ALD process:

[0010] When the CVD process is performed, the carrier gas purge is stopped and the conical process tank is evacuated to a vacuum, and then acetylene process gas is introduced to perform carbon coating on the deposited silicon surface until the process is completed;

[0011] When the ALD process is carried out, the carrier gas purge is stopped to reduce the temperature of the conical process tank to the required temperature range, the conical process tank is evacuated to the preset pressure and then stopped, and then the first precursor and the second precursor are introduced in a cycle to perform adsorption / reaction until the process is completed. Before the first precursor or the second precursor is introduced, the carrier gas must be introduced for purging and the vacuum must be evacuated to the preset pressure.

[0012] Furthermore, a heating device is provided in the conical process tank.

[0013] Furthermore, the process gas circuit includes a silane gas circuit and a carbon source gas circuit, and the silane gas circuit and the carbon source gas circuit are respectively provided with a control valve and a flow meter.

[0014] Furthermore, the precursor gas circuit at least includes a first precursor gas circuit and a second precursor gas circuit, and the first precursor gas circuit and the second precursor gas circuit are respectively provided with control valves.

[0015] Furthermore, the carrier gas circuit is provided with a gas branch to be connected to the second precursor gas circuit.

[0016] Furthermore, the vacuum system is connected to the conical process tank via a filter element device.

[0017] The present invention also provides a deposition process, using the deposition system capable of implementing the CVD process and the ALD process, comprising the following steps:

[0018] S1. Turn on the spiral stirring mechanism and rotate it at a low speed to heat the negative electrode powder to the temperature required by the process, and evacuate the conical process tank to the preset pressure;

[0019] S2, continuously introducing silane gas and high-purity nitrogen into the conical process tank, and keeping the conical process tank evacuated, silane flows through the powder area, cracking reaction occurs, and silicon is deposited on the surface of the negative electrode powder;

[0020] S3, when the silane flow rate reaches the set value, stop introducing the silane gas, and keep the high-purity nitrogen gas for a period of time to blow away the residual reaction by-products;

[0021] S4. Select CVD process or ALD process according to the needs:

[0022] When the CVD process is selected, the following steps are performed:

[0023] S41.1. Stop nitrogen purging, evacuate the conical process tank to a preset pressure, and then introduce acetylene and high-purity nitrogen into the tank. Keep evacuating the conical process tank. The acetylene gas flows through the powder area, causing a cracking reaction and depositing a carbon coating on the deposited silicon surface.

[0024] S41.2, carbon deposition coating to the required thickness until the process is completed;

[0025] When the ALD process is selected, the following steps are performed:

[0026] S42.1. Stop nitrogen purging, lower the tank temperature to the temperature range required by the ALD process, evacuate the conical process tank to a preset pressure, slow down or stop evacuating the conical process tank, introduce the first precursor into the conical process tank, and perform flow or pressure-maintaining adsorption / reaction;

[0027] S42.2, introducing a carrier gas to purge and remove the first precursor that has not been adsorbed, and evacuating to a preset pressure;

[0028] S42.3. Slow down or stop pumping gas from the conical process tank, introduce the second precursor into the conical process tank, and react by flowing or maintaining pressure;

[0029] S42.4, introducing a carrier gas to purge and remove the second precursor that has not reacted with the first precursor and the byproducts of the reaction between the first precursor and the second precursor, and evacuating to a preset pressure;

[0030] S42.5. Repeat steps S42.1 to S42.4 until the ALD coating reaches the required thickness and the process is completed.

[0031] Beneficial effects:

[0032] This solution can carry out silicon-carbon deposition process under vacuum. Under the premise of using metal hard seal to ensure vacuum sealing, it can ensure that the process is completely isolated from the air environment, so as to achieve safe and controllable process. In a vacuum negative pressure environment, other gas components are relatively small, and the silicon source is easier to enter the negative electrode material. The gas coating efficiency is higher, and the process completion time is shorter, which can improve the process efficiency. In addition to the functions of fluidized bed and rotary furnace, this solution introduces ALD process, which can realize more diverse passivation film coating solutions after silicon deposition process. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 It is a structural schematic diagram of a deposition system capable of implementing a CVD process and an ALD process according to an embodiment of the present invention;

[0034] Figure 2 It is a schematic diagram of a deposition process flow of a deposition system capable of implementing a CVD process and an ALD process according to an embodiment of the present invention; DETAILED DESCRIPTION

[0035] Example 1

[0036] Combination Figure 1 This embodiment provides a deposition system capable of implementing CVD process and ALD process, comprising a high temperature resistant conical process tank 1 suitable for storing powder, a vacuum system 7 connected above the conical process tank 1, and a gas source system connected below the conical process tank 1; wherein,

[0037] The gas source system includes a process gas circuit, a precursor gas circuit and a carrier gas circuit 2 connected to the conical process tank 1; a plurality of valves are provided in the gas source system for switching and controlling the gas circuit connected to the conical process tank 1;

[0038] The conical process tank 1 is provided with a spiral stirring mechanism 8, and the spiral stirring mechanism 8 is suitable for lifting the powder upward from the bottom of the cone for stirring;

[0039] After silicon is deposited on the powder, the valve of the gas source system is controlled to select whether to continue the CVD process or the ALD process:

[0040] When the CVD process is performed, the carrier gas purge is stopped and the conical process tank 1 is evacuated to a vacuum, and then acetylene process gas is introduced to perform carbon coating on the deposited silicon surface until the process is completed;

[0041] When the ALD process is carried out, the carrier gas purge is stopped to reduce the temperature of the conical process tank 1 to the required temperature range, the conical process tank 1 is evacuated to a preset pressure and then stopped, and then the first precursor 3 and the second precursor 4 are introduced in a cycle to perform adsorption / reaction until the process is completed, and before the first precursor 3 or the second precursor 4 is introduced, the carrier gas must be introduced for purging and the vacuum must be evacuated to the preset pressure.

[0042] In this embodiment, the conical process tank 1 is made of high temperature resistant material, which can realize high temperature process of 800℃~1000℃. A heating device 9 is arranged in the conical process tank 1, and the heating device 9 is arranged in the lower part of the conical process tank 1. There is no heating device 9 in the upper part of the conical process tank 1, so that the silane is cracked in the lower part of the conical process tank 1, and is directly extracted by the vacuum device after rising to the top. A spiral stirring mechanism 8 is arranged in the conical process tank 1, and the spiral stirring mechanism 8 has a spiral blade, which can continuously lift the negative electrode powder at the bottom of the conical process tank 1 from the bottom of the cone upward during the rotation process, thereby stirring the negative electrode powder at the bottom of the conical process tank 1, and can assist the process gas or precursor to blow the negative electrode powder from bottom to top, so that the negative electrode powder is fully in contact with the process gas or precursor, reducing the use of the process gas or precursor. At the same time, this solution adopts the structure of a conical process tank 1, and the process gas or precursor is blown upward from the conical bottom part of the tank body, which can make the gas quickly diffuse upward along the conical structure and improve the process efficiency.

[0043] The gas source system includes multiple process gas circuits, multiple precursor gas circuits and a carrier gas circuit 2. Specifically, in this embodiment, two process gas circuits and two precursor gas circuits are used as an example for description, but in other embodiments, more process gas circuits and precursor gas circuits may be provided.

[0044] In this embodiment, the process gas circuit includes a silane gas circuit 5 and a carbon source gas circuit 6, and the silane gas circuit 5 and the carbon source gas circuit 6 are respectively provided with control valves V1, V2 and flow meters; the precursor gas circuit at least includes a first precursor 3 gas circuit and a second precursor 4 gas circuit, and the first precursor 3 gas circuit and the second precursor 4 gas circuit are respectively provided with control valves V3, V4, and the carrier gas circuit 2 is provided with a gas branch to connect to the second precursor 4 gas circuit, and the second precursor 4 can be carried by the carrier gas. The carrier gas circuit 2 is provided with a control valve V5.

[0045] The vacuum system 7 is connected to the conical process tank 1 through a filter element device. The vacuum system 7 includes a vacuum pump and a pressure valve PV3, which are used to vacuum the conical process tank 1. During the silicon deposition process, the system is continuously vacuumed to keep the conical process tank 1 in a negative pressure state. In the negative pressure state, there are relatively few other gas components, and the silicon source is easier to enter the negative electrode material. The gas coating efficiency is higher, the process is completed in a shorter time, and the process efficiency can be improved.

[0046] In this embodiment, since the CVD process is carried out while maintaining a negative pressure vacuum state, and the conical process tank 1 can operate in a high temperature environment, and the high temperature ALD process is also required to be subjected to negative pressure treatment, and the conical process tank 1 can withstand the problems required by the high temperature ALD process, the CVD process or the ALD process can be selectively carried out through the present deposition system, especially after the silane is deposited, the CVD process or the ALD process can be switched as needed by controlling the vacuum system 7, the heating system and the gas source system. In another embodiment, the ALD process can also be switched after the CVD process is completed. Through this solution, when silicon-carbon deposition is carried out on the titanium nitride negative electrode powder, the CVD process and the ALD process can be implemented on the same deposition equipment, which greatly improves the process efficiency. After the silicon deposition process is realized through the CVD process, the ALD process can be used to realize a richer and more diverse passivation film coating scheme.

[0047] Compared with the fluidized bed and rotary kiln solutions, this embodiment adopts "vacuum vertical stirring combined with bottom air intake" for silicon-carbon deposition process. Vacuum vertical stirring combined with bottom air intake replaces gas fluidization powder with stirring. More powder can be loaded under the same volume, and the gas intake resistance is reduced, ensuring sufficient diffusion and contact of gas in the powder, which can realize industrial mass production. This solution can carry out silicon-carbon deposition process under vacuum. On the premise of using metal hard seal to ensure reliable vacuum sealing, it can ensure that the process is completely isolated from the air environment, so as to realize safe and controllable process. Since silicon is generally deposited, due to the high activity of elemental silicon, it will burn in the air. Therefore, it is necessary to coat the surface of elemental silicon with a layer of carbon after deposition, or to oxidize the surface silicon. In addition to the functions of fluidized bed and rotary kiln, this embodiment also introduces ALD process, which can realize more diverse passivation film coating schemes after silicon deposition process.

[0048] Example 2

[0049] Combination Figure 2 As shown, the present invention also provides a deposition process, using the deposition system capable of implementing the CVD process and the ALD process, comprising the following steps:

[0050] S1, start the spiral stirring mechanism 8 to rotate at a low speed, heat the negative electrode powder to the temperature required by the process, and evacuate the conical process tank 1 to a preset pressure;

[0051] S2, continuously introducing silane gas and high-purity nitrogen into the conical process tank 1, and keeping evacuating the conical process tank 1, so that silane flows through the powder area, a cracking reaction occurs, and silicon is deposited on the surface of the negative electrode powder;

[0052] S3, when the silane flow rate reaches the set value, stop introducing the silane gas, and keep the high-purity nitrogen gas for a period of time to blow away the residual reaction by-products;

[0053] S4. Select CVD process or ALD process according to the needs:

[0054] When the CVD process is selected, the following steps are performed:

[0055] S41.1. Stop nitrogen purging, evacuate the conical process tank 1 to a preset pressure, and then introduce acetylene and high-purity nitrogen into the tank. Keep evacuating the conical process tank 1. The acetylene gas flows through the powder area, causing a cracking reaction, and depositing a carbon coating on the deposited silicon surface;

[0056] S41.2, carbon deposition coating to the required thickness until the process is completed;

[0057] When the ALD process is selected, the following steps are performed:

[0058] S42.1. Stop nitrogen purging, lower the tank temperature to the temperature range required by the ALD process, and then evacuate the conical process tank 1 to a preset pressure, then slow down or stop evacuating the conical process tank 1, and introduce the first precursor 3 into the conical process tank 1 for flow or pressure-maintaining adsorption / reaction;

[0059] S42.2, introducing a carrier gas to purge and remove the first precursor 3 that has not been adsorbed, and evacuating to a preset pressure;

[0060] S42.3, slowing down or stopping the vacuuming of the conical process tank 1, introducing the second precursor 4 into the conical process tank 1, and reacting by flowing or maintaining pressure;

[0061] S42.4, introducing a carrier gas to purge and remove the second precursor 4 that has not reacted with the first precursor 3 and the byproducts of the reaction between the first precursor 3 and the second precursor 4, and evacuating to a preset pressure;

[0062] S42.5. Repeat steps S42.1 to S42.4 until the ALD coating reaches the required thickness and the process is completed.

[0063] Through the scheme of this embodiment, the introduction of the vacuum ALD process can realize the surface passivation film coating after the silicon deposition process, which can bring more possibilities for users to explore the silicon-carbon coating process.

[0064] It should be noted that, in another embodiment, after the CVD process, steps S42.1 to S42.5 may be performed immediately, so that the ALD process may be continued after the CVD process is completed to meet different coating requirements.

[0065] 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.

[0066] 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 deposition system capable of implementing CVD process and ALD process, comprising a high temperature resistant conical process tank suitable for storing powder, characterized in that: It also includes a vacuum system connected above the conical process tank, and a gas source system connected below the conical process tank; wherein, The gas source system includes a plurality of process gas circuits, a precursor gas circuit, and a carrier gas circuit connected to the conical process tank; a plurality of control valves are provided in the gas source system for switching and controlling the gas circuits connected to the conical process tank; A spiral stirring mechanism is provided in the conical process tank, and the spiral stirring mechanism is suitable for lifting the powder upward from the bottom of the cone for stirring; After silicon is deposited on the powder, the control valve of the gas source system is controlled to select whether to continue the CVD process or the ALD process: When the CVD process is performed, the carrier gas purge is stopped and the conical process tank is evacuated to a vacuum, and then acetylene process gas is introduced to perform carbon coating on the deposited silicon surface until the process is completed; When the ALD process is carried out, the carrier gas purge is stopped to reduce the temperature of the conical process tank to the required temperature range, the conical process tank is evacuated to the preset pressure and then stopped, and then the first precursor and the second precursor are introduced in a cycle to perform adsorption / reaction until the process is completed. Before the first precursor or the second precursor is introduced, the carrier gas must be introduced for purging and the vacuum must be evacuated to the preset pressure.

2. The deposition system capable of implementing CVD process and ALD process according to claim 1, characterized in that: A heating device is arranged in the conical process tank.

3. The deposition system capable of implementing CVD process and ALD process according to claim 1, characterized in that: The process gas circuit comprises a silane gas circuit and a carbon source gas circuit, and the silane gas circuit and the carbon source gas circuit are respectively provided with a control valve and a flow meter.

4. The deposition system capable of implementing CVD process and ALD process according to claim 1, characterized in that: The precursor gas circuit at least includes a first precursor gas circuit and a second precursor gas circuit, and the first precursor gas circuit and the second precursor gas circuit are respectively provided with control valves.

5. The deposition system capable of implementing CVD process and ALD process according to claim 4, characterized in that: The carrier gas circuit is provided with a gas branch to be connected to the second precursor gas circuit.

6. The deposition system capable of implementing CVD process and ALD process according to claim 1, characterized in that: The vacuum system is connected to the conical process tank via a filter element device.

7. A deposition process, characterized in that: The deposition system capable of implementing the CVD process and the ALD process according to any one of claims 1 to 6 comprises the following steps: S1. Turn on the spiral stirring mechanism and rotate it at a low speed to heat the negative electrode powder to the temperature required by the process, and evacuate the conical process tank to the preset pressure; S2, continuously introducing silane gas and high-purity nitrogen into the conical process tank, and keeping the conical process tank evacuated, silane flows through the powder area, cracking reaction occurs, and silicon is deposited on the surface of the negative electrode powder; S3, when the silane flow rate reaches the set value, stop introducing the silane gas, and keep the high-purity nitrogen gas for a period of time to blow away the residual reaction by-products; S4. Select CVD process or ALD process according to the needs: When the CVD process is selected, the following steps are performed: S41.

1. Stop nitrogen purging, evacuate the conical process tank to a preset pressure, and then introduce acetylene and high-purity nitrogen into the tank. Keep evacuating the conical process tank. The acetylene gas flows through the powder area, causing a cracking reaction and depositing a carbon coating on the deposited silicon surface. S41.2, carbon deposition coating to the required thickness until the process is completed; When the ALD process is selected, the following steps are performed: S42.

1. Stop nitrogen purging, lower the tank temperature to the temperature range required by the ALD process, evacuate the conical process tank to a preset pressure, slow down or stop evacuating the conical process tank, introduce the first precursor into the conical process tank, and perform flow or pressure-maintaining adsorption / reaction; S42.2, introducing a carrier gas to purge and remove the first precursor that has not been adsorbed, and evacuating to a preset pressure; S42.

3. Slow down or stop pumping gas from the conical process tank, introduce the second precursor into the conical process tank, and react by flowing or maintaining pressure; S42.4, introducing a carrier gas to purge and remove the second precursor that has not reacted with the first precursor and the byproducts of the reaction between the first precursor and the second precursor, and evacuating to a preset pressure; S42.

5. Repeat steps S42.1 to S42.4 until the ALD coating reaches the required thickness and the process is completed.

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