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

Abstract

The utility model provides a deposition system capable of realizing a CVD (Chemical Vapor Deposition) process and an ALD (Atomic Layer 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 conical bottom 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 utility model relates to the technical field of semiconductor processing equipment, specifically, relates to a deposition system can realize CVD process and ALD process. BACKGROUND

[0002] The existing negative material titanium nitride realizes the scheme of silicon carbon deposition mainly has fluidized bed scheme and rotary furnace scheme, the fluidized bed scheme is through the airflow blowing, makes the powder material suspension in the reaction container, with the gas phase or liquid phase fully carries out the contact and the reaction, thereby realizes the silicon carbon deposition, and the rotary furnace scheme is to load the powder in the rotary furnace, slowly rotates the hearth and imports the gas to the furnace to carry out the contact and the reaction, thereby realizes the silicon carbon deposition. However, in the fluidized bed scheme, generally realizes in the micro-positive pressure environment, through the large airflow to raise the powder to realize the gas and the powder fully reaction, but its gas intake is relatively big, the bed body diameter is limited by the fluidization effect and cannot be big, can only increase the fluidization height, this leads to the very difficult realization single chamber, single batch capacity improvement, it is more difficult to realize the industrialized mass production. For the rotary furnace scheme, the powder and the gas are difficult to realize the full contact, and the process time is long, and the process effect is a little worse than the fluidized bed.

[0003] At present, CVD process and high temperature ALD process are designed separately, because titanium nitride process needs to be realized at high temperature, and conventional ALD process is generally carried out at low temperature (within 400 DEG C), therefore, conventional ALD system cannot be used for titanium nitride process, if CAD process and high temperature ALD process are realized on titanium nitride, two sets of equipment are needed to complete, but this may lead to pollution in the material flow transfer process, and the process efficiency is also relatively low. UTILITY MODEL CONTENTS

[0004] The utility model discloses a deposition system can realize CVD process and ALD process to solve the problem mentioned above.

[0005] The utility model adopts the following scheme:

[0006] A deposition system can realize CVD process and ALD process, including the high temperature resistant conical process tank suitable for storing powder, also including the vacuum system connected on the conical process tank top and the gas source system connected on the conical process tank cone bottom, wherein,

[0007] The gas source system includes a plurality of process gas gas paths, precursor gas paths and carrier gas gas paths connected to the conical process tank, a plurality of control valves are arranged in the gas source system to switch and control the gas paths connected with the conical process tank,

[0008] The conical process tank is provided with a stirring mechanism, and the stirring mechanism is suitable for lifting and stirring the powder from the cone bottom upwards.

[0009] The deposition system is configured to switch between CVD process or ALD process by controlling the opening and closing of the vacuum system and the control valve of the gas source system.

[0010] Further, the conical process tank is provided with a heating device.

[0011] Further, the process gas gas circuit includes a silane gas circuit and a carbon source gas circuit, and the control valve and flow meter are arranged on the silane gas circuit and the carbon source gas circuit respectively.

[0012] Further, the precursor gas circuit includes at least 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.

[0013] Further, the carrier gas gas circuit is provided with a gas branch to be connected to the second precursor gas circuit.

[0014] Further, the vacuum system is connected to the conical process tank through a filter core device.

[0015] Beneficial effects:

[0016] The silicon-carbon deposition process can be carried out under vacuum, and under the premise of using metal hard sealing to ensure vacuum sealing, the process can be completely isolated from the air environment to realize process safety and controllability. Under the vacuum negative pressure environment, other gas components are less, the silicon source is easier to enter the inside of the negative material, the gas coating efficiency is higher, the process completion time is shorter, and the process efficiency can be improved; in addition to the functions of the fluidized bed and the rotary furnace, the ALD process is introduced, and after the deposition silicon process, more diverse passivation film coating schemes can be realized. BRIEF DESCRIPTION OF DRAWINGS

[0017] Figure 1 is a structure schematic view of a deposition system capable of realizing CVD process and ALD process according to an embodiment of the present application;

[0018] Figure 2 is a deposition process flow schematic view of a deposition system capable of realizing CVD process and ALD process according to an embodiment of the present application; DETAILED DESCRIPTION

[0019] Embodiment 1

[0020] In combination Figure 1 The embodiment provides a deposition system capable of realizing CVD process and ALD process, which comprises 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 to the bottom of the conical process tank 1; wherein,

[0021] The gas source system includes a process gas gas path, a precursor gas path, and a carrier gas gas path 2 connected to the conical process tank 1; a plurality of valves are arranged in the gas source system for switching control of the gas paths communicated with the conical process tank 1;

[0022] The conical process tank 1 is provided with a spiral stirring mechanism 8 adapted to stir the powder upward from the bottom of the cone;

[0023] After the silicon is deposited on the powder, the valves of the gas source system are controlled to select to continue the CVD process or the ALD process:

[0024] When the CVD process is performed, the carrier gas purging is stopped, the conical process tank 1 is pumped to vacuum, and then acetylene process gas is introduced to perform carbon coating on the deposited silicon surface until the process is completed;

[0025] When the ALD process is performed, the carrier gas purging is stopped, the temperature of the conical process tank 1 is reduced to the required temperature range, the conical process tank 1 is pumped to a preset pressure, 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 the carrier gas purging and pumping to a preset pressure are required before the first precursor 3 or the second precursor 4 is introduced.

[0026] In this embodiment, the conical process tank 1 is made of high-temperature resistant material, which can realize a high-temperature process of 800-1000°C. A heating device 9 is arranged in the lower part of the conical process tank 1, and the upper part of the conical process tank 1 is not provided with the heating device 9, so that the silane is cracked in the lower part of the conical process tank 1, and is directly pumped out by the vacuum device after rising to the top. The conical process tank 1 is provided with a spiral stirring mechanism 8 having a spiral paddle, which can continuously lift the negative electrode powder at the bottom of the conical process tank 1 upward during rotation, thereby stirring the negative electrode powder at the bottom of the conical process tank 1, and assisting the process gas or the precursor to blow the negative electrode powder upward, so that the negative electrode powder is in full contact with the process gas or the precursor, reducing the use amount of the process gas or the precursor. At the same time, the conical process tank 1 is adopted in this scheme, and the process gas or the precursor is blown upward from the bottom of the tank body, which can make the gas quickly diffuse upward along the conical structure, improving the process efficiency.

[0027] The gas source system includes a plurality of process gas gas paths, a plurality of precursor gas paths, and a carrier gas gas path 2. Specifically, in this embodiment, two process gas gas paths and two precursor gas paths are taken as an example for illustration, but in other embodiments, more process gas gas paths and precursor gas paths can be provided.

[0028] In the embodiment, the process gas gas path includes a silane gas path 5 and a carbon source gas path 6, the silane gas path 5 and the carbon source gas path 6 are respectively provided with control valves V1, V2 and flow meters; the precursor gas path includes at least a first precursor 3 gas path and a second precursor 4 gas path, and the first precursor 3 gas path and the second precursor 4 gas path are respectively provided with control valves V3, V4, the carrier gas path 2 is provided with a gas branch to be connected to the second precursor 4 gas path, and the second precursor 4 can be carried by the carrier gas. The carrier gas path 2 is provided with a control valve V5.

[0029] The vacuum system 7 is connected to the conical process tank 1 through a filter core device. The vacuum system 7 is provided with a vacuum pump and a pressure valve PV3 for vacuum extraction of the conical process tank 1. During the silicon deposition process, the system is continuously vacuum extracted to keep the conical process tank 1 in a negative pressure state, and the negative pressure state has less other gas components, the silicon source is easier to enter the negative material, the gas coating efficiency is higher, the process completion time is shorter, and the process efficiency can be improved.

[0030] In the embodiment, since the CVD process is carried out in a negative pressure vacuum state, the conical process tank 1 can operate in a high temperature environment, and the high temperature ALD process also needs to be processed in a negative pressure state, and the conical process tank 1 can withstand the problems required by the high temperature ALD process, so the deposition system can selectively carry out the CVD process or the ALD process, especially after the silane is deposited, the CVD process or the ALD process can be switched by controlling the vacuum system 7, the heating system and the gas source system according to the needs. In another embodiment, the ALD process can be switched after the CVD process is completed. Through the scheme, when the titanium nitride negative electrode powder is subjected to silicon-carbon deposition, the CVD process and the ALD process can be realized on the same deposition equipment, which greatly improves the process efficiency, and after the deposition silicon process is realized by the CVD process, a more diverse passivation film coating scheme can be realized by the ALD process.

[0031] Compared with the fluidized bed and rotary furnace scheme, the embodiment scheme adopts a "vacuum vertical stirring combined with bottom gas inlet mode" to carry out the silicon-carbon deposition process. The vacuum vertical stirring combined with bottom gas inlet mode uses stirring to replace gas fluidization of the powder, can realize loading of more powder in the same volume, reduces the gas inlet resistance, ensures sufficient diffusion and contact of the gas in the powder, and can realize industrialized mass production. The scheme can carry out the silicon-carbon deposition process under vacuum, and under the premise of ensuring reliable vacuum sealing by using a metal hard seal, can ensure that the process is completely isolated from the air environment, and realizes process safety and controllability. Since the elemental silicon is highly active after general deposition, it will burn in the air, and therefore a layer of carbon needs to be coated on the surface of the deposited elemental silicon, or the surface layer of the elemental silicon needs to be oxidized. The embodiment scheme has the functions of the fluidized bed and rotary furnace, and further introduces the ALD process, and can realize a more diverse passivation film coating scheme after the deposition silicon process.

[0032] Embodiment 2

[0033] In combination Figure 2 As shown in the utility model still provides a kind of deposition process, use the deposition system that can realize CVD process and ALD process, comprising the following steps:

[0034] S1, open spiral stirring mechanism 8 low-speed rotation, heat negative electrode powder to the temperature required by process, conical process tank 1 is vacuumized to preset pressure;

[0035] S2, continuously import silane gas and high-purity nitrogen into conical process tank 1, keep conical process tank 1 to be pumped, silane flows through powder area, and occurs cracking reaction, and deposits silicon on the surface of negative electrode powder;

[0036] S3, when the silane flow reaches the set value, stop importing silane gas, at this time, keep a period of time of high-purity nitrogen continuous purging, and blow away residual reaction by-products;

[0037] S4, according to need selection carries out CVD process or ALD process:

[0038] When CVD process is selected, the following steps are executed:

[0039] S41.1, stop nitrogen purging, after conical process tank 1 is vacuumized to preset pressure, simultaneously import acetylene and high-purity nitrogen into the tank, keep conical process tank 1 to be pumped, acetylene gas flows through powder area, and occurs cracking reaction, and deposits carbon coating on the surface of deposited silicon;

[0040] S41.2, carbon deposition coating is required to the required thickness, until the process is completed;

[0041] When ALD process is selected, the following steps are executed:

[0042] S42.1, stop the nitrogen purge, reduce the temperature of the tank to the required temperature range of the ALD process, then vacuum the conical process tank 1 to a preset pressure, slow down or stop the pumping of the conical process tank 1, and introduce the first precursor 3 into the conical process tank 1, and flow or pressure adsorption / reaction;

[0043] S42.2, introduce the carrier gas, purge the first precursor 3 that fails to be adsorbed, and vacuum to a preset pressure;

[0044] S42.3, slow down or stop the pumping of the conical process tank 1, introduce the second precursor 4 into the conical process tank 1, and flow or pressure reaction;

[0045] S42.4, introduce the carrier gas, purge the second precursor 4 that fails to react with the first precursor 3 and the by-products of the reaction of the first precursor 3 and the second precursor 4, and vacuum to a preset pressure;

[0046] S42.5, repeat the steps of S42.1-S42.4 until the ALD coating reaches the required thickness, and the process is complete.

[0047] Through the embodiment scheme, the introduction of the vacuum ALD process can realize the surface passivation film coating after the silicon deposition process, and can bring more possibilities for users to explore the silicon-carbon coating process.

[0048] It should be noted that in another embodiment, after the CVD process is performed, the steps of S42.1-S42.5 can be performed immediately to continue the ALD process after the CVD process is completed to meet different coating requirements.

[0049] 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 solution belonging to the idea of the present application is within the protection scope of the present application.

[0050] The above introduction of the drawings used in the embodiments only shows some embodiments of the present application, and should not be considered as limiting the scope, and for those skilled in the art, other related drawings can be obtained without creative labor.

Claims

1. A deposition system capable of CVD and ALD processes, comprising a high temperature resistant conical process tank adapted to store a powder, characterized in that, Further comprising a vacuum system connected above the conical process tank, and a gas source system connected at the conical bottom of the conical process tank; wherein, The gas source system comprises several process gas gas paths, precursor gas paths and carrier gas gas paths connected to the conical process tank; several control valves are arranged in the gas source system for switching control of the gas paths communicated with the conical process tank; A stirring mechanism is arranged in the conical process tank, and the stirring mechanism is adapted to stir the powder upward from the conical bottom; The deposition system is configured to realize CVD process or ALD process by controlling the opening and closing of the vacuum system and the control valves of the gas source system.

2. The CVD and ALD process enabled deposition system of claim 1, wherein, A heating device is arranged in the conical process tank.

3. The CVD and ALD process enabled deposition system of claim 1, wherein, The process gas gas paths comprise a silane gas path and a carbon source gas path, and control valves and flow meters are respectively arranged on the silane gas path and the carbon source gas path.

4. The CVD and ALD process enabled deposition system of claim 1, wherein, The precursor gas paths at least comprise a first precursor gas path and a second precursor gas path, and the first precursor gas path and the second precursor gas path are respectively provided with control valves.

5. The CVD and ALD process enabled deposition system of claim 4, wherein, The carrier gas gas path is provided with a gas branch to be connected to the second precursor gas path.

6. The CVD and ALD process enabled deposition system of claim 1, wherein, The vacuum system is connected to the conical process tank through a filter core device.

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