CVD equipment for curved cavity coating

Abstract

A CVD apparatus for curved cavity deposition is disclosed, comprising: an evaporation chamber for vaporizing an evaporation source to form a deposition gas; a gas delivery assembly connected to the evaporation chamber for delivering the deposition gas; and a deposition chamber connected to the gas delivery assembly for depositing the deposition gas onto a substrate surface to form a thin film. One side of the input assembly is located within the deposition chamber, and a temperature control structure is provided on the side of the input assembly located within the deposition chamber to control the temperature of the deposition gas. This CVD apparatus for curved cavity deposition reduces the problem of pipe blockage caused by condensation or deposition of the deposition gas within the gas delivery assembly by using a temperature control structure on the gas delivery assembly. Furthermore, the nozzle design and the ability of the sample to be horizontally displaced and rotated also make CVD deposition of curved films possible.

Description

Technical Field

[0001] This invention relates to the field of thin film deposition technology, and in particular to a CVD apparatus for curved cavity deposition. Background Technology

[0002] Chemical vapor deposition (CVD) is an important method for preparing thin film materials. This method delivers gaseous chemicals to a heated substrate, where a chemical reaction occurs on the substrate surface to form a thin film. CVD has many advantages over other deposition methods: 1) It eliminates the need for the deposition material to be directly exposed on the substrate, allowing for the deposition of films in complex areas, which is beneficial for the preparation of non-planar films; 2) It offers a fast deposition rate, reaching μm / min when the required deposition conditions are met. However, currently commercially available CVD equipment is only suitable for preparing planar films and lacks the ability to prepare curved films. Furthermore, because the nozzle of the gaseous material needs to extend into the deposition chamber during CVD, and the deposition chamber is equipped with a heating furnace, the high temperature inside the deposition chamber can easily cause the gaseous material to react and deposit at the nozzle, clogging the nozzle.

[0003] As the core of radio frequency superconducting technology, the radio frequency superconducting cavity (RF superconducting cavity) is widely used in emerging accelerator facilities (such as LHC, EXFEL, LCLS-II, FRIB, etc.) due to its advantages of low loss and high acceleration gradient during continuous wave or long pulse operation. Nb3Sn cavities, fabricated by depositing Nb3Sn thin films on the inner walls of niobium or copper curved cavities, offer higher performance, higher operating temperatures, and lower operating costs compared to traditional pure niobium cavities. In 2019, Fermilab predicted that after the LCLS-II-HE project, future high-energy radio frequency superconducting accelerators and small-scale industrial high-power accelerators would fully transition to niobium-tin technology. Therefore, developing Nb3Sn curved cavity coating processes has enormous market potential and significant strategic importance. Summary of the Invention

[0004] In view of the above problems, the purpose of the present invention is to provide a CVD equipment for curved cavity coating, which controls the temperature of the deposit gas by setting a temperature control structure on the gas delivery component, thereby reducing the problem of pipeline blockage caused by condensation or deposition of deposit gas in the gas delivery component.

[0005] According to one aspect of the present invention, a CVD apparatus for curved cavity deposition is provided, comprising: an evaporation chamber for vaporizing an evaporation source to form a deposition gas; a gas delivery assembly connected to the evaporation chamber for delivering the deposition gas; and a deposition chamber connected to the gas delivery assembly for depositing the deposition gas on a substrate surface to form a thin film; wherein one side of the input assembly is located inside the deposition chamber, and a temperature control structure is provided on the side of the input assembly located inside the deposition chamber for controlling the temperature of the deposition gas.

[0006] Optionally, the gas delivery assembly further includes: a second pipe connecting the evaporation chamber and the deposition chamber for delivering the deposition gas, wherein the nozzle of the second pipe is located in the deposition chamber; and a heating structure surrounding a portion of the second pipe for heating the deposition gas within the second pipe.

[0007] Optionally, the temperature control structure surrounds a portion of the nozzle side of the second pipe for controlling the temperature of the deposited gas at the nozzle inside the second pipe.

[0008] Optionally, the temperature control structure uses oil insulation, and the portion surrounding the second pipe includes two layers, with oil flowing from the outer layer into the inner layer or from the inner layer into the outer layer.

[0009] Optionally, the nozzle of the second pipe is a cone, cross, or shower head type.

[0010] Optionally, the gas delivery assembly further includes: a plurality of thermocouples, evenly distributed on the second pipe, for reading the temperature of the deposited gas in the second pipe.

[0011] Optionally, the evaporation chamber includes: at least two evaporation chambers for placing an evaporation source; a heater connected to each evaporation chamber for vaporizing the evaporation source; and a first conduit connected to each evaporation chamber for conveying the deposit gas.

[0012] Optionally, the evaporation chamber further includes: a plurality of thermocouples, evenly distributed on each evaporation chamber and the first pipe, for reading the temperature of the deposited gas in the evaporation chamber and the first pipe.

[0013] Optionally, depending on the number of evaporation chambers, the first pipe may be a two-way or multi-way pipe, and the second pipe may be connected to the first pipe.

[0014] Optionally, the deposition temperature of the deposit on the coating substrate surface within the deposition chamber is 650℃-1200℃.

[0015] Optionally, it further includes: a transition cavity connected to the deposition cavity, used to transfer the coating substrate and to evacuate the deposition cavity.

[0016] Optionally, the transition cavity includes a conveying structure for fixing the coating substrate and controlling the movement of the coating substrate.

[0017] Optionally, during the deposition of the inner wall of the curved substrate, the transition cavity controls the relative movement of the coating substrate and the nozzle along the axial direction of the coating substrate.

[0018] Optionally, during the deposition of the inner wall of the curved substrate, the transition cavity controls the rotation of the coating substrate along the axial direction.

[0019] The CVD equipment for curved cavity coating provided by this invention is a device for a large-area curved surface coating method based on CVD technology. Deposit gas is transported between the evaporation chamber and the deposition chamber through a gas supply component. At the same time, a heating structure and a temperature control structure are set on the gas supply component to keep the deposit gas in the gas supply component at a relatively suitable temperature. This prevents the deposit gas from reacting in the second pipe of the gas supply component due to excessively high or low temperatures (too high temperature) or condensing and blocking the pipe (too low temperature).

[0020] Furthermore, thermocouples are installed at different locations on the gas transmission assembly, which allows for real-time monitoring of the temperature of the sediment gas in the assembly. The temperature of the sediment gas can then be adjusted through heating and temperature control structures, thereby improving the temperature control capability of the sediment gas in the gas transmission assembly.

[0021] Furthermore, the nozzles of the second pipe in the gas delivery assembly are cone-shaped, cross-shaped, or sprinkler-shaped, etc. The unique nozzle shape design allows for more uniform spraying of deposited gas in all directions; the rotation of the coating substrate and the back-and-forth movement relative to the nozzle during the film-forming process can make the film growth more uniform; the programmable back-and-forth displacement and rotation of the sample rod in the transition chamber can flexibly control the nozzle residence time or perform compensatory growth, thereby making the film growth more uniform.

[0022] Furthermore, this application presents a novel design where the gas delivery assembly and temperature control structure reduce the likelihood of reactants reacting (due to excessively high temperatures) or condensing and clogging the pipe (due to excessively low temperatures) in the second pipe. The nozzle design of the second pipe ensures more uniform deposition of gas in all directions. The coating substrate can move and rotate horizontally, and with the nozzle design and programmable control, the nozzle dwell time can be flexibly controlled or compensatory growth can be performed, thus making it possible to deposit a uniform thin film on the inner or outer wall of the curved coating substrate. Attached Figure Description

[0023] The above and other objects, features and advantages of the present invention will become more apparent from the following description of embodiments of the invention with reference to the accompanying drawings, in which:

[0024] Figure 1 A front view of a CVD apparatus for curved cavity coating according to an embodiment of the present invention is shown;

[0025] Figure 2 A top view of a CVD apparatus for curved cavity coating according to an embodiment of the present invention is shown;

[0026] Figure 3 A schematic diagram of the evaporation chamber of a CVD apparatus for curved cavity coating according to an embodiment of the present invention is shown;

[0027] Figure 4A schematic diagram of the gas delivery assembly of a CVD apparatus for curved cavity coating according to an embodiment of the present invention is shown;

[0028] Figure 5 A schematic diagram of the heating structure in the gas delivery assembly of a CVD apparatus for curved cavity coating according to an embodiment of the present invention is shown. Detailed Implementation

[0029] The invention will now be described in more detail with reference to the accompanying drawings. In the various drawings, the same elements are indicated by similar reference numerals. For clarity, the various parts in the drawings are not drawn to scale. Furthermore, some well-known parts may not be shown. For simplicity, the semiconductor structure obtained after several steps can be depicted in a single figure.

[0030] It should be understood that when describing the structure of a device, when referring to a layer or region as being "above" or "on top of" another layer or region, it can mean that it is directly above another layer or region, or that it contains other layers or regions between it and another layer or region. Furthermore, if the device is flipped, that layer or region will be located "below" or "under" another layer or region.

[0031] To describe a situation where it is located directly on another layer or another area, this article will use the expressions "directly on top of" or "on and adjacent to".

[0032] The specific embodiments of the present invention will be described in further detail below with reference to the accompanying drawings and examples.

[0033] Figure 1 A front view of a CVD apparatus for curved cavity coating according to an embodiment of the present invention is shown; Figure 2 A top view of a CVD apparatus for curved cavity coating according to an embodiment of the present invention is shown; Figure 3 A schematic diagram of the evaporation chamber of a CVD apparatus for curved cavity coating according to an embodiment of the present invention is shown; Figure 4 A schematic diagram of the gas delivery assembly of a CVD apparatus for curved cavity coating according to an embodiment of the present invention is shown; Figure 5 A schematic diagram of the heating structure in the gas delivery assembly of a CVD apparatus for curved cavity coating according to an embodiment of the present invention is shown.

[0034] refer to Figure 1 and Figure 2The CVD equipment 100 for curved cavity deposition includes: an evaporation chamber 110, a gas delivery assembly 120, a deposition chamber 130, a transition chamber 140, a vacuum pump assembly 150, a support 160, a temperature control assembly 170, a mechanical pump assembly 180, and a motor assembly 190. The evaporation chamber 110, the gas delivery assembly 120, the deposition chamber 130, and the transition chamber 140 are supported on the surface of the support 160. The vacuum pump assembly 150 is also supported on the support 160, but located below the surface of the support 160. The temperature control assembly 170, the mechanical pump assembly 180, and the motor assembly 190 are located on one side of the support 160.

[0035] The evaporation chamber 110 houses the evaporation source. The deposition gas generated by the evaporation source enters the deposition chamber 130 via the gas delivery assembly 120. The transition chamber 140 carries the coating substrate and delivers it to the deposition chamber 130 so that the deposition gas can deposit on the surface of the coating substrate. The thermostatic assembly 170 is connected to the gas delivery assembly 120 and controls the temperature of the deposition gas in the gas delivery assembly 120. The mechanical pump assembly 180 is connected to the vacuum pump assembly 150 and provides a vacuum environment for the deposition chamber 130 and the transition chamber 140. The motor assembly 190 is connected to the transition chamber 140 and controls its movement.

[0036] In this embodiment, the gas delivery assembly 120 includes multiple structures for controlling the deposited gas to be maintained at a certain temperature, thereby reducing the probability of the deposited gas undergoing a deposition reaction in the pipeline of the gas delivery assembly 120, which could lead to blockage of the gas delivery assembly 120.

[0037] Furthermore, such as Figure 3 As shown, the evaporation chamber 110 is used to vaporize the evaporation source, and its structure includes: at least two evaporation chambers 113, a heater 112 connected to each evaporation chamber 113 respectively, a plurality of thermocouples 115 connected to each evaporation chamber 113 respectively, and a first pipe 116 connected to each evaporation chamber 113 respectively.

[0038] At least two evaporation chambers 113 are used to house evaporation sources 114. Different evaporation chambers 113 are not interconnected and can house the same or different evaporation sources 114. A heater 112 is connected to each evaporation chamber 113 to heat the evaporation source 114 within the chamber, thereby vaporizing the material within the evaporation source to form a deposit gas. Multiple thermocouples 115 are connected to each evaporation chamber 113 to monitor the temperature of the evaporation source. A first conduit 116 is connected to each evaporation chamber 113 to transport the deposit gas formed by the vaporization of the material within the evaporation source to the gas delivery assembly 120.

[0039] In this embodiment, in order to smoothly transport the deposited gas to the deposition chamber 130 via the gas delivery pipe 120, a carrier gas can be used, so each evaporation chamber 113 in the evaporation chamber 110 also has an air inlet (not shown in the figure). The carrier gas enters the evaporation chamber 113 from the air inlet, and carries the deposited gas in the evaporation chamber 113 together to the deposition chamber 130 via the first pipe 116 and the gas delivery assembly 120.

[0040] In this embodiment, for example, it is used for depositing Nb3Sn thin films in a low-temperature superconducting resonant cavity, wherein the evaporation source 114 can be selected from NbCl5 and SnCl2 when preparing the Nb3Sn thin film. The carrier gas can be, for example, Ar gas, H2 gas, etc.

[0041] Furthermore, the first pipe 116 is also equipped with heating wires and thermocouples to precisely control the temperature in the first pipe 116 and prevent the deposited gas from reacting (too high temperature) or condensing (too low temperature) in the first pipe 116 due to excessively high or low temperatures, which could lead to blockage of the first pipe 116.

[0042] Further, refer to Figure 4 The gas delivery assembly 120 includes a second conduit 121, a heating structure 123, and a temperature control structure 124. The second conduit 121 is connected to a first conduit 116 of the evaporation chamber 110 and is used to transport deposited gas. The heating structure 123 surrounds a portion of the second conduit 121 and is used to heat the deposited gas in the second conduit 121. The temperature control structure 124 surrounds another portion of the second conduit 121 and is used to maintain the temperature of the deposited gas in the second conduit 121.

[0043] refer to Figure 4 and Figure 5 The heating structure 123 surrounds a portion of the second pipe 121 near the evaporation chamber 110. Since the deposited gas enters the second pipe 121 from the evaporation chamber 110, its temperature may be reduced. Therefore, the heating structure 123 can heat the deposited gas in the second pipe 121 to reduce the risk of the deposited gas condensing in the second pipe 121 due to low temperature, which could cause blockage of the second pipe 121.

[0044] The temperature control structure 124 surrounds the portion of the second pipe 121 located in the deposition chamber 130 near the nozzle. Since the deposited gas requires a higher temperature to react in the deposition chamber 130, in this embodiment, taking the deposition of a Nb3Sn thin film on a niobium substrate as an example, the operating temperature of the deposition chamber 130 for preparing the Nb3Sn thin film can reach 1100-1200℃. Therefore, the temperature of the portion of the second pipe 121 near the nozzle will rise. Thus, the temperature control structure 124 can maintain the temperature of the deposited gas in the second pipe 121 at 600-1100℃, reducing the risk of the deposited gas at the nozzle of the second pipe 121 reacting due to excessive temperature and depositing at the nozzle, thus preventing blockage of the second pipe 121. If a niobium-tin thin film is grown on a copper substrate, the deposition temperature is 650-830℃, and the temperature of the deposited gas in the second pipe 121 needs to be controlled below 650℃.

[0045] Furthermore, the temperature control structure 124 employs an oil insulation system, meaning that flowing oil is used within the temperature control structure 124. (Reference) Figure 4 The temperature control structure 124 is connected to the inlet 126 and the outlet 125 to facilitate oil flow. Furthermore, the temperature control structure 124 employs a double-layer structure: the inlet 126 is connected to the inner layer of the temperature control structure 124, and the outlet 125 is connected to the outer layer of the temperature control structure 124. Figure 4 The dashed lines in the temperature control structure 124, inlet 126 and outlet 125 indicate the flow path of oil in the temperature control structure 124.

[0046] Furthermore, the temperature control structure 124 is connected to the thermostatic component 170 via the inlet 126 and the outlet 125, and the thermostatic component 170 controls the temperature of the heat-insulating oil, thereby controlling the temperature of the deposit gas in the second pipe 121.

[0047] In addition, the gas delivery assembly 120 also includes a flange interface 122, which is used to fix and seal the deposition chamber 130. The second pipe 121 passes through the flange interface 122, and the heating structure 123 and the temperature control structure 124 are located on the same side of the flange interface 122, that is, the heating structure 123 and the temperature control structure 124 are both located inside the deposition chamber 130.

[0048] In addition, the nozzle of the second pipe 121 extends into the cavity wall of the coating substrate. In order to improve the uniformity of the film on the inner wall of the coating substrate, nozzles of shapes such as cone (i.e. oblique), cross, and sprinkler can be used according to the collision of the curved coating substrate.

[0049] The deposit gas reacts in the deposition chamber 130, depositing a thin film on the cavity wall of the coating substrate. The deposition chamber 130 is a quartz tube, and an annular cylindrical heating furnace (not shown in the figure) is located outside to heat the deposition chamber 130, causing the deposit gas to react and deposit on the cavity wall of the coating substrate. The heating furnace can be moved left and right by the lower guide rail to change the relative position of the heating furnace on the quartz tube. The quartz tube is connected to the gas supply assembly 120 on one side and to the transition chamber 140 on the other side through a sealing device.

[0050] The transition cavity 140 is used to transfer the coating substrate and to evacuate the deposition cavity 130. Therefore, the transition cavity 140 includes at least a transfer structure and a vacuum structure.

[0051] The transition chamber 140 is connected to the vacuum pump assembly 150 via a flange interface and a gate valve at its lower part. During evacuation, the airflow direction is evaporation chamber 110, gas delivery assembly 120, deposition chamber 130, transition chamber 140, and vacuum pump assembly 150.

[0052] The other end of the transition cavity 140 is connected to a sample rod, which has a sample holder on it. The curved coating substrate can be installed on the sample holder and extended into the deposition cavity 130 through the sample rod. The sample rod is equipped with an automatic displacement platform, which allows the sample rod to move back and forth.

[0053] The sample rod is equipped with an electrically driven horizontal displacement and rotation platform. During the coating process, the nozzle of the gas delivery assembly 120 moves relative to the axis of the coating substrate. Combined with the rotation of the coating substrate, the programmable system controlling the translation and rotation speeds, and compensating for deposition, the thin film preparation becomes more uniform.

[0054] The CVD equipment for curved cavity coating provided by this invention transmits deposit gas between the evaporation chamber and the deposition chamber through a gas delivery component. At the same time, a heating structure and a temperature control structure are set on the gas delivery component to keep the deposit gas in the gas delivery component at a relatively suitable temperature. This prevents the deposit gas from reacting in the second pipe of the gas delivery component due to excessively high or low temperatures (too high temperature) or condensing and blocking the pipe (too low temperature).

[0055] Furthermore, thermocouples are installed at different locations on the gas transmission assembly, which allows for real-time monitoring of the temperature of the sediment gas in the assembly. The temperature of the sediment gas can then be adjusted through heating and temperature control structures, thereby improving the temperature control capability of the sediment gas in the gas transmission assembly.

[0056] Furthermore, the nozzles of the second pipe in the gas delivery assembly are cone-shaped, cross-shaped, or sprinkler-shaped, etc. The unique nozzle shape design allows for more uniform spraying of deposited gas in all directions; the rotation of the coating substrate and the back-and-forth movement relative to the nozzle during the film-forming process can make the film growth more uniform; the programmable back-and-forth displacement and rotation of the sample rod in the transition chamber can flexibly control the nozzle residence time or perform compensatory growth, thereby making the film growth more uniform.

[0057] Furthermore, this application presents a novel design where the gas delivery assembly and temperature control structure reduce the likelihood of reactants reacting (due to excessively high temperatures) or condensing and clogging the pipe (due to excessively low temperatures) in the second pipe. The nozzle design of the second pipe ensures more uniform deposition of gas in all directions. The coating substrate can move and rotate horizontally, and with the nozzle design and programmable control, the nozzle dwell time can be flexibly controlled or compensatory growth can be performed, thus making it possible to deposit a uniform thin film on the inner or outer wall of the curved coating substrate.

[0058] As described above, these embodiments of the present invention do not exhaustively cover all details, nor do they limit the invention to the specific embodiments described. Clearly, many modifications and variations can be made based on the above description. This specification selects and specifically describes these embodiments to better explain the principles and practical applications of the invention, thereby enabling those skilled in the art to effectively utilize the invention and its modifications. The invention is limited only by the claims and their full scope and equivalents.

Claims

1. A CVD apparatus for coating a curved surface cavity, characterized by comprising: The application relates to a thin film deposition device, which comprises: an evaporation cavity for vaporizing an evaporation source to form a deposition gas; a gas conveying assembly connected with the evaporation cavity for conveying the deposition gas; a deposition cavity connected with the gas conveying assembly for depositing the deposition gas on a surface of a film-coated substrate to form a thin film; a transition cavity connected with the deposition cavity for conveying the film-coated substrate and vacuumizing the deposition cavity; wherein one side of the gas conveying assembly is located in the deposition cavity, a side of a nozzle of the gas conveying assembly located in the deposition cavity is provided with a temperature control structure for controlling the temperature of the deposition gas, and the nozzle of the gas conveying assembly extends into a cavity wall of the film-coated substrate; the temperature control structure adopts oil insulation and comprises two layers, and oil flows from the outer layer into the inner layer or from the inner layer into the outer layer; the transition cavity is connected with a sample rod, the sample rod is provided with a sample holder, the film-coated substrate is installed on the sample holder, the film-coated substrate extends into the deposition cavity through the sample rod, and the sample rod is provided with an automatic horizontal displacement and rotation platform, so that the sample rod drives the film-coated substrate to move horizontally along the axis direction of the film-coated substrate and rotate during the deposition process, and the nozzle of the gas conveying assembly moves relative to the film-coated substrate.

2. The curved cavity coated CVD apparatus of claim 1, wherein, The gas conveying assembly further comprises: a second pipeline connected with the evaporation cavity and the deposition cavity for conveying the deposition gas, and a nozzle of the second pipeline is located in the deposition cavity; a heating structure surrounding a part of the second pipeline for heating the deposition gas in the second pipeline.

3. The curved cavity coated CVD apparatus of claim 2, wherein, The temperature control structure surrounds a part of the side of the nozzle of the second pipeline for controlling the temperature of the deposition gas at the nozzle of the second pipeline.

4. The curved cavity coated CVD apparatus of claim 2, wherein, The nozzle of the second pipeline adopts a conical type, a cross type or a shower type.

5. The curved cavity coated CVD apparatus of claim 3, wherein, The gas conveying assembly further comprises: a plurality of thermocouples uniformly distributed on the second pipeline for reading the temperature of the deposition gas in the second pipeline.

6. The curved cavity coated CVD apparatus of claim 2, wherein, The evaporation cavity comprises: at least two evaporation chambers for placing evaporation sources; a heater connected with each evaporation chamber for vaporizing the evaporation sources; a first pipeline connected with each evaporation chamber for conveying the deposition gas.

7. The curved cavity coated CVD apparatus of claim 6, wherein, The evaporation cavity further comprises: a plurality of thermocouples uniformly distributed on each evaporation chamber and the first pipeline for reading the temperature of the deposition gas in the evaporation chamber and the first pipeline.

8. The curved cavity coated CVD apparatus of claim 6, wherein, According to the number of the evaporation chambers, the first pipeline adopts a two-way or multi-way structure, and the second pipeline is connected with the first pipeline.

9. The curved cavity coated CVD apparatus of claim 2, wherein, The temperature of the deposition gas deposited on the surface of the film-coated substrate in the deposition cavity is 650 DEG C-1200 DEG C.

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