Deposition film flatness improving structure and chemical vapor deposition device

Abstract

The utility model relates to a deposited film flatness improving structure and a chemical vapor deposition device. The deposited film flatness improving structure comprises a back plate and a plurality of conveying pipes, the back plate is installed at the top of a deposition cavity of the chemical vapor deposition device, a first through hole and a plurality of second through holes are formed in the back plate in the thickness direction of the back plate, the first through hole is located in the center of the back plate, and the second through holes are evenly distributed adjacent to the edge of the back plate; conveying pipes are arranged corresponding to the first through hole and all the second through holes respectively, the first through hole and the second through holes are communicated with the corresponding conveying pipes, and the ends, away from the back plate, of the conveying pipes are connected with an air source. The deposited film flatness improving structure disclosed by the utility model is applied to the chemical vapor deposition device, so that the deposited film on the substrate is smoother, and the residual film in the deposition chamber can be thoroughly removed.

Description

Technical Field

[0001] The utility model relates to the technical field of manufacturing equipment for display devices, in particular to a structure for improving the flatness of a deposited film and a chemical vapor deposition device. Background Art

[0002] At present, CVD (Chemical Vapor Deposition) is widely used in the preparation of display devices and other semiconductors. CVD refers to a process in which a gaseous reactant containing elements constituting a thin film or a vapor of a liquid reactant and other gases required for the reaction are introduced into a deposition chamber from the central position of a back plate at the top of the chemical vapor deposition device and diffused, forming a plasma and depositing on the surface of a substrate to generate a thin film. For a television, a rectangular glass plate is usually used as the substrate for preparing the television display screen.

[0003] Reference Figure 1 , a conventional chemical vapor deposition device includes a deposition chamber, the deposition chamber has a deposition cavity, a back plate 1' is installed at the top of the deposition cavity, and a diffuser 2' is fixed below the back plate 1'. The back plate 1' is provided with a through hole 3' at its central position. When using this chemical vapor deposition device for chemical vapor deposition, there are the following deficiencies:

[0004] (1). The reactant can only be introduced into the deposition chamber from the through hole 3' at the central position of the back plate 1', and it is difficult to make the reactants at the central position and the four corner positions of the deposition cavity uniform, resulting in a phenomenon that the deposited film on the glass plate is thick in the middle and thin at the four corners. For a rectangular glass plate, the flatness of the deposited film is even worse.

[0005] (2). During the chemical vapor deposition process, residual films will be formed inside the deposition chamber. When a certain thickness is accumulated, an etching agent needs to be used for cleaning. However, since the etching agent can also only be introduced from the central position of the back plate 1' and diffused through the diffuser 2', most of the etching agent is distributed at the central position of the deposition cavity. Therefore, there will be a phenomenon that the etching rate of the residual film at the central position of the deposition chamber is much greater than that of the residual film at the four corner positions, resulting in incomplete cleaning at the four corner positions. When the residual films at the four corners are relatively thick, they will fall onto the substrate, resulting in defects. Therefore, when the accumulated residual films are too many, only the deposition chamber can be opened for cleaning and maintenance, and this maintenance process usually costs a lot of money. Summary of the Utility Model

[0006] An object of the utility model is to provide a structure for improving the flatness of a deposited film, which can effectively improve the flatness of the deposited film on a substrate and can completely remove the residual films in the deposition chamber.

[0007] Another object of the present utility model is to provide a chemical vapor deposition device. By using this chemical vapor deposition device, a deposition film with excellent flatness can be prepared on a substrate, and self-cleaning can be achieved without disassembly and cleaning, and the cleaning and maintenance cost is low.

[0008] To achieve this purpose, the present utility model adopts the following technical solutions:

[0009] A deposition film flatness improvement structure is provided, including a back plate and a plurality of delivery pipes;

[0010] Among them, the back plate is installed at the top of the deposition chamber of the chemical vapor deposition device. A first through hole and a plurality of second through holes are axially penetrated through the back plate along its thickness direction. The first through hole is located at the center position of the back plate, and the plurality of second through holes are evenly distributed adjacent to the edge of the back plate;

[0011] A delivery pipe is respectively provided corresponding to the first through hole and all the second through holes. The first through hole and the second through holes are communicated with the corresponding delivery pipes, and one end of all the delivery pipes away from the back plate is connected to a gas source.

[0012] As a further solution of the deposition film flatness improvement structure, a throttle valve and a controller are further included. A throttle valve is installed on each delivery pipe, and the throttle valve is electrically connected to the controller.

[0013] As a further solution of the deposition film flatness improvement structure, the back plate is a rectangular structure. A plurality of the second through holes are arranged at intervals on each diagonal line of the back plate, and the plurality of second through holes located on the two diagonal lines are centrosymmetric about the first through hole.

[0014] As a further solution of the deposition film flatness improvement structure, a first distributor is further included. The first distributor includes a first distribution plate. The first distribution plate is disposed opposite to the first through hole and below the back plate. A plurality of first through holes penetrating through the first distribution plate along the thickness direction of the first distribution plate are formed on the first distribution plate.

[0015] As a further solution of the deposition film flatness improvement structure, a plurality of second distributors are further included. The second distributors are disposed opposite to the second through holes one by one. The second distributor includes a second distribution plate. The second distribution plate is disposed opposite to the second through hole and below the back plate. A plurality of second through holes penetrating through the second distribution plate along the thickness direction of the second distribution plate are formed on the second distribution plate.

[0016] As a further solution for the structure to improve the flatness of the deposited film, the number of the second through holes is four, and further includes four driving devices and four slide rails installed at the bottom of the back plate. The four slide rails are located on the diagonal line of the back plate and are symmetric with respect to the center of the first through hole;

[0017] Four second distributors, the second distributors are connected to the corresponding second through holes through metal hoses. A sleeve with a 90° corner is sleeved on the outer periphery of the metal hose and adjacent to the second distributor. The sleeve is slidably matched with the slide rail. Each driving device is fixedly connected to the outside of the sleeve on the outer periphery of the corresponding metal hose, and the driving device can drive the sleeve to slide along the length direction of the slide rail.

[0018] As a further solution for the structure to improve the flatness of the deposited film, the driving device includes a cylinder block installed adjacent to the back plate on the side wall of the deposition chamber and a piston rod connected to the cylinder block. One end of the piston rod away from the cylinder block is fixedly connected to the sleeve, and the length direction of the piston rod is the same as the length direction of the slide rail.

[0019] As a further solution for the structure to improve the flatness of the deposited film, all the first through holes are evenly distributed on the first distribution plate, and all the second through holes are evenly distributed on the second distribution plate.

[0020] As a further solution for the structure to improve the flatness of the deposited film, it further includes a diffuser, the diffuser is fixedly connected to the lower end of the back plate, and the diffuser is spaced below the first distributor and the second distributor.

[0021] On the other hand, a chemical vapor deposition device is provided, including a deposition chamber with a deposition cavity inside. The top of the deposition cavity is provided with the above-mentioned structure for improving the flatness of the deposited film.

[0022] The beneficial effects of the present utility model compared with the prior art:

[0023] In the structure for improving the flatness of the deposited film of the present utility model, by opening a first through hole in the center of the back plate and evenly opening a plurality of second through holes adjacent to its outer periphery, the first through hole and each second through hole are respectively connected to a gas source through a delivery pipe, and the reaction gases pass through the back plate through the first through hole and the second through holes respectively and are introduced into the deposition chamber of the chemical vapor deposition device, so that the plasma is evenly distributed in the deposition cavity of the deposition chamber, thereby improving the flatness of the deposited film on the substrate.

[0024] When the residual film in the deposition chamber reaches a certain thickness, the etching agent for cleaning can be directly introduced into the deposition chamber through the first through hole and each second through hole to etch the residual film in each area, thereby achieving the effect of self-cleaning.

[0025] By installing throttle valves on each delivery pipe and controlling the opening degree of the throttle valves through a controller, the gas flow rate in each delivery pipe can be adjusted. For the area with a relatively large deposition film thickness, the opening degree of the throttle valve on the delivery pipe closest to this area can be reduced or closed. For the area with a relatively small deposition film thickness, the opening degree of the throttle valve on the delivery pipe closest to this area can be increased or fully opened, which can save the reaction gas while ensuring excellent flatness of the deposition film.

[0026] For the self-cleaning of the chemical vapor deposition device, it only needs to adjust the opening degree of the throttle valve on the delivery pipe closest to the area with more residual film and a relatively large residual film thickness to be fully open through the controller. For the area without residual film, the throttle valve on the delivery pipe closest to this area can be directly closed through the controller. For the area with less residual film, the throttle valve on the delivery pipe closest to this area can be opened to a certain extent through the controller, which can effectively save the etching agent for cleaning and reduce the cleaning and maintenance cost. Brief Description of the Drawings

[0027] The present utility model will be further described in detail below with reference to the drawings and embodiments.

[0028] Figure 1 It is a schematic assembly diagram of a backplane, a diffuser, and a gas source in the prior art.

[0029] Figure 2 It is a schematic diagram of the structure for improving the flatness of the deposition film in Embodiment 1 of the present utility model.

[0030] Figure 3 It is a schematic diagram of the backplane in Embodiment 1 of the present utility model.

[0031] Figure 4 It is a schematic diagram of the structure for improving the flatness of the deposition film in Embodiment 2 of the present utility model.

[0032] Figure 5 It is a schematic diagram of the backplane in Embodiment 2 of the present utility model.

[0033] Figure 6 It is a schematic diagram of the cooperation between the slider and the slide rail in Embodiment 2 of the present utility model.

[0034] Figure 1 In which:

[0035] 1’, backplane; 2’, diffuser; 3’, diffuser;

[0036] Figures 2 to 6 In which:

[0037] 1. Backplane; 2. First through-hole; 3. Second through-hole; 4. Delivery pipe; 5. First distributor; 6. Second distributor; 7. Diffuser; 8. Driving device; 81. Cylinder block; 82. Piston rod; 9. Slide rail; 91. Trapezoidal chute; 10. Metal hose; 11. Sleeve; 12. Slide block; 13. Connecting plate; 14. Limit block; 15. Protection box. Detailed implementation mode

[0038] Referring to the embodiments described in detail below in conjunction with the drawings, the advantages and features of the present utility model and the methods for realizing them will become apparent. However, the present utility model is not limited to the embodiments disclosed below, but can be implemented in various different forms. The provision of these embodiments is only for the purpose of completing the disclosure of the present utility model and enabling those skilled in the art to fully understand the scope of the present utility model, and the present utility model is only defined by the scope of the claims. The same reference numerals denote the same components throughout the specification.

[0039] Hereinafter, the present utility model will be described in detail with reference to the drawings.

[0040] Embodiment 1

[0041] Refer to Figure 2 and Figure 3 , the deposition film flatness improvement structure of this embodiment includes a backplane 1 and a plurality of delivery pipes 4.

[0042] Backplane 1, the backplane 1 is installed at the top of the deposition chamber of the chemical vapor deposition device. The backplane 1 is provided with a first through-hole 2 and a plurality of second through-holes 3 penetrating along its thickness direction. The first through-hole 2 is located at the center position of the backplane 1, and the plurality of second through-holes 3 are evenly distributed adjacent to the edge of the backplane 1;

[0043] One delivery pipe 4 is provided corresponding to the first through-hole 2 and all the second through-holes 3 respectively. The first through-hole 2 and the second through-holes 3 are communicated with the corresponding delivery pipes 4, and one end of all the delivery pipes 4 far from the backplane 1 is connected to a gas source.

[0044] In this embodiment, the gas for preparing the deposition film in the gas source can be introduced into the deposition chamber through each delivery pipe 4 at the same time to form a plasma, and the plasma can be evenly distributed in the deposition chamber, so that a deposition film with excellent flatness can be obtained on the substrate.

[0045] The installation method of the backplane 1 in the deposition chamber is a conventional technique in the art and will not be described in detail here.

[0046] In this embodiment, the delivery pipe 4 is made of alumina.

[0047] Among them, for the display screen of a display device such as a television, the substrate usually adopts a rectangular glass plate. Next, taking the preparation of a deposition film on a rectangular glass plate as an example, the deposition film flatness improvement structure of this embodiment will be further described in detail.

[0048] For a rectangular glass plate, the deposition chamber of the chemical vapor deposition device is a cuboid structure. Correspondingly, the backplane 1 is also a rectangular structure. When using a conventional backplane, the deposition film will be thick in the middle and thin at the four corners. For this reason, in this embodiment, a second through hole 3 is respectively opened near the four corners of the backplane 1, which can supplement the gas-rare regions at the four corners of the deposition chamber, improve the uniformity of the plasma in the deposition chamber, and thus a deposition film with excellent flatness can be obtained.

[0049] Furthermore, a plurality of second through holes 3 are arranged at intervals on each diagonal line of the backplane 1, and the plurality of second through holes 3 located on the two diagonal lines are centrosymmetric about the first through hole 2. Adopting this structural design can specifically supplement the gas-rare regions at the four corners of the deposition chamber.

[0050] Furthermore, the deposition film flatness improvement structure of this embodiment further includes a first distributor 5. The first distributor 5 includes a first distribution disc, the first distribution disc faces the first through hole 2 and is arranged below the backplane 1, and a plurality of first through holes penetrating through the first distribution disc in the thickness direction of the first distribution disc are opened on the first distribution disc. By installing the first distributor 5 facing the first through hole 2 below the backplane 1, the reaction gas at the central position of the deposition chamber is evenly diffused through the first distributor 5.

[0051] Furthermore, the deposition film flatness improvement structure of this embodiment further includes a plurality of second distributors 6. The second distributors 6 are arranged in one-to-one correspondence with the second through holes 3. The second distributor 6 includes a second distribution disc, the second distribution disc faces the second through hole 3 and is arranged below the backplane 1, and a plurality of second through holes penetrating through the second distribution disc in the thickness direction of the second distribution disc are opened on the second distribution disc. By installing the second distributor 6 facing the second through hole 3 below the backplane 1, the reaction gas at the four-corner positions can be evenly diffused through the second distributor 6.

[0052] In order to further improve the uniformity of the reaction gas distribution, in this embodiment, all the first through holes are evenly distributed on the first distribution disc and all the second through holes are evenly distributed on the second distribution disc.

[0053] Furthermore, the deposition film flatness improvement structure of this embodiment further includes a diffuser 7. The diffuser 7 is fixedly connected to the lower end of the back plate 1 and is spaced below the first distributor 5 and the second distributor 6. Among them, a plurality of channels penetrate through the diffuser 7 in its thickness direction, and the plurality of channels are evenly distributed. The reaction gas is preliminarily diffused by the first distributor 5 and the second distributor 6 and then further diffused by the diffuser 7, so that the plasma can be evenly distributed throughout the deposition chamber, and finally a rectangular deposition film with excellent flatness is prepared on the glass plate.

[0054] On the basis of ensuring the preparation of a deposition film with excellent flatness, this embodiment further optimizes the above deposition film flatness improvement structure, that is, the delivery pipe 4 is improved.

[0055] Specifically, the deposition film flatness improvement structure of this embodiment further includes a throttle valve and a controller ( (not shown in the figure). A throttle valve is installed on each delivery pipe 4, and the throttle valve is electrically connected to the controller. The opening degree of the throttle valve can be controlled by the controller, so as to realize the adjustment of the reaction gas flow rate in each delivery pipe 4.

[0056] Among them, the throttle valve is a conventional instrument in the field of automatic control, and its specific structure and principle will not be elaborated here.

[0057] This embodiment also provides a chemical vapor deposition device, including a deposition chamber. There is a deposition cavity in the deposition chamber, and the deposition film flatness improvement structure described in the above embodiment is arranged at the top of the deposition cavity.

[0058] When performing chemical vapor deposition on a rectangular glass plate placed in the deposition cavity of the chemical vapor deposition device, first, the throttle valves on all the delivery pipes 4 are opened through the controller for chemical vapor deposition. After the deposition is completed, all the throttle valves are closed, and the flatness of the deposition film is checked. If there is a relatively thin area, the throttle valve on the delivery pipe 4 closest to this area is opened through the controller.

[0059] In this embodiment, the controller can accurately control the corner torque of the valve disc in the throttle valve, so as to achieve the purpose of accurately controlling the valve angle in real time and ensuring the stable pressure in the deposition cavity.

[0060] When there is too much residual film in the deposition chamber, the deposition chamber needs to be self-cleaned. Specifically, first, the throttle valve on the delivery pipe 4 connected to the first through-hole 2 is opened through the controller, and the etchant is introduced into the deposition chamber. After cleaning for about 50 seconds, the throttle valve on the delivery pipe 4 connected to the second through-hole 3 is then opened in sequence. After about 650 seconds, all the residual film in the deposition chamber can be etched away. The main component of the etchant used to remove the residual film is NF3 gas, and the main product after etching is SiF4 gas, which can be pumped out through the pipe at the bottom of the deposition chamber by a vacuum pump. Of course, it is also possible to first open the throttle valve on the delivery pipe 4 connected to the second through-hole 3 to etch the residual film at the four corners of the deposition chamber for about 600 seconds, and then close the throttle valve on the delivery pipe 4 connected to the second through-hole 3. At the same time, open the throttle valve on the delivery pipe 4 connected to the first through-hole 2 to etch the residual film at the central position of the deposition chamber for about 100 seconds, and all the residual film in the deposition chamber can also be etched away. In actual operation, the opening degree and opening time of the throttle valve of the delivery pipe 4 corresponding to a certain position can also be adjusted in real time according to the thickness of the residual film at that position, so as to achieve fixed-point removal of the residual film and save the etchant.

[0061] Of course, the deposition film flatness improvement structure of this embodiment is not limited to chemical vapor deposition treatment of rectangular glass plates, and is also applicable to substrates of other shapes. Similarly, the deposition chamber is a cuboid structure, and the corresponding backplane 1 is also a rectangular structure, but it is also applicable to backplanes and deposition chambers of other shapes.

[0062] In this embodiment, the deposition film flatness improvement structure is made of a metal material that is heat-resistant and corrosion-resistant.

[0063] The technical effect of this embodiment is that the deposition film flatness improvement structure of this embodiment can introduce the reaction gases respectively through the first through-hole 2 and the second through-hole 3 through the backplane 1 into the deposition chamber of the chemical vapor deposition device, so that the plasma is evenly distributed in the deposition chamber, thereby improving the flatness of the deposition film on the substrate. And, by installing throttle valves on the delivery pipes 4, the gas flow rate of each delivery pipe 4 can be adjusted according to actual needs, achieving the effect of saving reactants.

[0064] The deposition film flatness improvement structure of this embodiment also has a self-cleaning function. When the residual film in the deposition chamber reaches a certain thickness, the gas source can be replaced with the etchant for cleaning to etch the residual film in each area of the deposition chamber, thereby achieving the effect of self-cleaning. In addition, according to the adjustment of the opening degree of the throttle valve on the delivery pipe 4, the etchant for cleaning can be saved under the condition of ensuring thorough cleaning, reducing the cleaning and maintenance cost.

[0065] Compared with the prior art, the cleaning of the chemical vapor deposition device of this embodiment is more efficient, can effectively reduce the occurrence of residual film, and improve the film formation quality.

[0066] Embodiment 2

[0067] This embodiment is further improved on the basis of the above-mentioned embodiment 1.

[0068] refer to Figure 4 and Figure 5 In the deposited film flatness improvement structure of this embodiment, the number of the second through holes 3 on the back plate 1 is four, and correspondingly, the number of the second distributors 6 is also four. Specifically, the deposited film flatness improvement structure also includes:

[0069] Four driving devices 8 and four slide rails 9 installed at the bottom of the back plate 1, the four slide rails 9 are located on the diagonal lines of the back plate 1 and are symmetrical with respect to the center of the first through hole 2;

[0070] The second distributor 6 is connected to the corresponding second through hole 3 through a metal hose 10. A sleeve 11 with a 90° corner is provided on the outer periphery of the metal hose 10 and adjacent to the second distributor 6, that is, the sleeve 11 is a 90° elbow. The sleeve 11 is slidably matched with the slide rail 9. Each driving device 8 is fixedly connected to the outer side of the sleeve 11 on the outer periphery of the corresponding metal hose 10. The driving device 8 can drive the sleeve 11 to drive the second distributor 6 to slide along the length direction of the slide rail 9.

[0071] In this embodiment, the driving device 8 can drive the sleeve 11 and drive the second distributor 6 to move to a specific position according to actual needs, so as to supplement the area with lower plasma concentration at a fixed point and further improve the flatness of the deposited film.

[0072] Among them, the sleeve 11 with a 90° corner is made of hard metal material and is mainly used to shape a section of the metal hose 10 adjacent to the second distributor 6 so that the end of the metal hose 10 connected to the second distributor 6 faces downward, so that the second distributor 6 faces the diffuser 7 below, that is, the second distributor 6 is parallel to the diffuser 7.

[0073] like Figure 6 As shown, the cross section of the slide rail 9 has a trapezoidal slide groove 91, and a slider 12 matching the trapezoidal slide groove 91 is provided on the sleeve 11, and the slider 12 can slide along the length direction of the slide rail 9. A connecting plate 13 is also provided on the outer periphery of the sleeve 11, and the connecting plate is fixedly connected to the driving device 8. Among them, the slide rail 9, the sleeve 11, the trapezoidal slider 12 and the connecting plate are all made of high temperature resistant and corrosion resistant metal materials, and the details are not repeated here.

[0074] In this embodiment, limit blocks 14 are respectively provided at both ends of the slide rail 9 , and the limit blocks 14 are detachably fixed to the slide rail 9 by screws, so as to facilitate the insertion of the slider 12 into the trapezoidal slide groove 91 .

[0075] Optionally, the driving device 8 includes a cylinder block 81 installed on the side wall of the deposition chamber adjacent to the back plate 1 and a piston rod 82 connected to the cylinder block 81. One end of the piston rod 82 away from the cylinder block 81 is fixedly connected to the sleeve 11, and the length direction of the piston rod 82 is the same as the length direction of the slide rail 9.

[0076] Wherein, the cylinder block 81 and the piston rod 82 are made of high-temperature resistant and corrosion-resistant metal materials.

[0077] Further, the cylinder block 81 can be installed in a protective box 15. The protective box 15 is provided with an avoidance hole, and the piston rod 82 passes through the avoidance hole and is fixedly connected to the connecting plate 13 outside the sleeve 11.

[0078] Wherein, the protective box 15 is made of high-temperature resistant and corrosion-resistant metal materials. Installing the cylinder block 81 in the protective box 14 can prevent the cylinder block 81 from being damaged.

[0079] This embodiment also provides a chemical vapor deposition device, including a deposition chamber with a deposition cavity inside. The top of the deposition cavity is provided with the deposition film flatness improvement structure as described above. The chemical vapor deposition device of this embodiment is basically the same as the first embodiment above, except for the deposition film flatness improvement structure, which will not be elaborated here.

[0080] Although the embodiments of the present invention have been described above with reference to the drawings, the present invention is not limited to the above embodiments, but can be manufactured in various forms, and those skilled in the art will understand that the present invention can be implemented in other specific forms without changing the technical spirit or basic characteristics of the present invention. Therefore, it should be understood that the above embodiments are exemplary in all aspects and not restrictive.

Claims

1. A deposited film flatness improvement structure, characterized in that: include: A back plate, the back plate is mounted on the top of the deposition chamber of the chemical vapor deposition device, the back plate is provided with a first through hole and a plurality of second through holes along the thickness direction thereof, the first through hole is located at the center of the back plate, and the plurality of second through holes are evenly distributed near the edge of the back plate; A delivery pipe is provided corresponding to the first through hole and all the second through holes respectively, the first through hole and the second through hole are connected to the corresponding delivery pipe, and one end of all the delivery pipes away from the back plate is connected to the gas source.

2. The deposited film flatness improvement structure according to claim 1, characterized in that: It also includes a throttle valve and a controller. Each of the delivery pipes is equipped with a throttle valve, and the throttle valve is connected to the controller.

3. The deposited film flatness improvement structure according to claim 1, characterized in that: The back plate is a rectangular structure, a plurality of the second through holes are arranged at intervals on each diagonal line of the back plate, and the plurality of the second through holes on two diagonals are symmetrical about the center of the first through hole.

4. The deposited film flatness improvement structure according to claim 1, characterized in that: It also includes a first distributor, which includes a first distribution plate. The first distribution plate is opposite to the first through hole and is arranged below the back plate. The first distribution plate is provided with a plurality of first through holes that penetrate the first distribution plate along the thickness direction of the first distribution plate.

5. The deposited film flatness improvement structure according to claim 4, characterized in that: It also includes a plurality of second distributors, which are arranged opposite to the second through holes one by one. The second distributor includes a second distribution plate, which is opposite to the second through holes and is arranged below the back plate. The second distribution plate is provided with a plurality of second through holes that penetrate the second distribution plate along the thickness direction of the second distribution plate.

6. The deposited film flatness improvement structure according to claim 4, characterized in that: The number of the second through holes is four, and further includes: Four driving devices and four slide rails installed at the bottom of the back plate, wherein the four slide rails are located on the diagonal lines of the back plate and are symmetrical with respect to the center of the first through hole; Four second distributors are connected to the corresponding second through holes through a metal hose, a sleeve with a 90° angle is provided on the outer periphery of the metal hose and adjacent to the second distributor, the sleeve is slidably matched with the slide rail, each of the driving devices is fixedly connected to the outer side of the sleeve on the outer periphery of the corresponding metal hose, and the driving device can drive the sleeve to slide along the length direction of the slide rail.

7. The deposited film flatness improvement structure according to claim 6, characterized in that: The driving device includes a cylinder body installed on the side wall of the deposition chamber adjacent to the back plate and a piston rod connected to the cylinder body. One end of the piston rod away from the cylinder body is fixedly connected to the sleeve, and the length direction of the piston rod is consistent with the length direction of the slide rail.

8. The deposited film flatness improvement structure according to claim 5, characterized in that: All of the first via holes are evenly distributed on the first distribution plate, and all of the second via holes are evenly distributed on the second distribution plate.

9. The deposited film flatness improvement structure according to claim 8, characterized in that: It also includes a diffuser, which is fixedly connected to the lower end of the back plate and is spaced below the first distributor and the second distributor.

10. A chemical vapor deposition device, comprising a deposition chamber, wherein the deposition chamber has a deposition cavity, characterized in that: The top of the deposition chamber is provided with a deposited film flatness improvement structure as described in any one of claims 1 to 9.

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