A gas uniform system applied to a PECVD coating chamber

Abstract

The utility model relates to photovoltaic coating equipment field discloses a kind of gas distribution system applied to PECVD coating cavity, including cavity, cavity upper cover, gas distribution box.The upper portion of gas distribution box includes an intermediate gas distribution area, four four-around gas distribution areas and two side edge gas distribution areas.Four-around gas distribution area is located in the four corners of cavity upper cover, with intermediate gas distribution area center as symmetry point, annular symmetry distribution;Side edge gas distribution area is respectively located in the left and right sides of intermediate gas distribution area.Correspondingly, the lower portion of intermediate gas distribution area, four-around gas distribution area, side edge gas distribution area is respectively provided with intermediate flow divider for regulating and controlling overall airflow, four-around flow divider for diffusing gas to cavity corner, side edge flow divider for assisting cavity center and four-around gas uniform flow.The area of intermediate gas distribution area, four-around gas distribution area, side edge distribution area and the area of corresponding flow divider decrease in turn.The utility model is complementary to each other by gas distribution area and area, and the gas distribution of entire gas distribution box is uniform.

Description

Technical Field

[0001] This utility model relates to the field of photovoltaic coating equipment, and in particular to a gas equalization system applied to a PECVD coating chamber. Background Technology

[0002] PECVD equipment can be used for photovoltaic cell coating. During coating, process gases are injected into the chamber, and coating is performed using ion-enhanced chemical vapor deposition. The uniformity of the process gas (specialty gas) injected into the PECVD equipment chamber is crucial to the uniformity of cell coating. To ensure uniform gas delivery, existing technologies employ a gas distribution box within the chamber, a gas distribution plate below the distribution box, and multiple air inlets and rinsing ports above the distribution box. Most commercially available systems use five air inlets: one in the center and one at each of the four corners, evenly distributed. A distribution plate is placed below each air inlet to achieve uniform gas delivery.

[0003] With the increasing demand for high-capacity PECVD, the chambers of PECVD equipment on the market are gradually increasing in size. This leads to larger coating areas and shorter cycle times, requiring more gas to be introduced. If existing gas delivery technologies are used while maintaining the same cycle time, increased gas flow rate and pressure are necessary. Current distribution plate structures widely employ a large central circle and radial strips. This structure causes most of the gas to flow out from the two strips. Although the gas doesn't concentrate in the middle, the gas entering from each inlet cannot be mutually replenished and evenly distributed, resulting in uneven gas distribution. Process gases can easily escape directly through the flow equalization holes near the inlets, causing locally thicker coatings and thinner coatings on wafers further away from the inlets (especially at the four corners), resulting in significant film thickness variation on individual wafers. Similarly, when using RPS to clean the chamber or carrier, uneven and incomplete cleaning occurs.

[0004] Therefore, there is an urgent need for a gas distribution system that can solve the problem of uneven gas distribution in large-chamber PECVD equipment to adapt to production. Utility Model Content

[0005] The purpose of this invention is to provide a gas distribution system for PECVD coating chambers. By using a zoned gas distribution method, the gas distribution box is divided into seven main zones, and different function and size distributors are set in each zone. This allows for mutual supplementation and coordination between zones to achieve uniform gas distribution, ultimately achieving uniform gas distribution throughout the entire gas distribution box and solving the problem of uneven gas distribution in some areas.

[0006] To achieve the above objectives, the present invention adopts the following technical solution:

[0007] This utility model discloses a gas distribution system for a PECVD coating cavity, comprising a cavity body and a cavity cover. A gas distribution box is disposed within the cavity body and located below the cavity cover; a gas distribution plate is located below the gas distribution box. The gas distribution box includes a central gas distribution area, four surrounding gas distribution areas, and two side gas distribution areas. The surrounding gas distribution areas are located at the four corners of the cavity cover and are symmetrically distributed in a ring with the center of the central gas distribution area as the symmetrical point. The side gas distribution areas are located on the left and right sides of the central gas distribution area, respectively. The area of ​​the central gas distribution area, the surrounding gas distribution areas, and the side distribution areas decreases sequentially.

[0008] The intermediate air distribution zone has a central air inlet, and below the central air inlet is an intermediate flow divider for regulating the overall airflow. The center of the intermediate flow divider has an upwardly protruding first guide cone, and around it are several radially distributed strip-shaped ventilation slots and baffles.

[0009] The center of the surrounding gas distribution area is provided with a surrounding air inlet; below the surrounding air inlet is a surrounding diffuser for diffusing gas to the corners of the cavity; the center of the surrounding diffuser is provided with an upwardly protruding second guide cone, and several radially distributed strip-shaped ventilation grooves and baffles are provided around it, with an annular ventilation groove on the outermost ring.

[0010] A side air inlet is provided at the center of the side air distribution area; below the side air inlet is a side flow divider for uniform gas flow in the center and around the auxiliary cavity; the side flow divider includes a diffuser for diverting gas to the surrounding areas and a flow equalization section for diverting gas downwards; the diffuser is "X" shaped and has four diffusion channels.

[0011] The upper surface area of ​​the middle splitter, the surrounding splitter, and the side splitter decreases sequentially.

[0012] Furthermore, both the intermediate splitter and the surrounding splitter are disc-shaped, and the area of ​​the intermediate splitter is 1.4-1.6 times the area of ​​the surrounding splitter.

[0013] Furthermore, the intermediate distributor includes a disk body, and the disk body has the following components distributed sequentially from the center to the periphery:

[0014] The first diversion zone, the first guide cone is located in the first diversion zone, and the first guide cone is provided with a plurality of first vent holes;

[0015] The second diversion zone has several second vent slots and second baffles evenly distributed on it, and the second vent slots occupy 30%-35% of the area of ​​the second diversion zone;

[0016] The third diversion zone has a plurality of third vent slots and third baffles evenly distributed on it, and the third vent slots occupy 25%-30% of the area of ​​the third diversion zone;

[0017] The fourth diversion zone is provided with a number of fourth vent slots and fourth baffles evenly spaced on it, and the fourth vent slots occupy 30%-35% of the area of ​​the fourth diversion zone.

[0018] The fifth diversion zone is provided with a plurality of fifth vent slots and fifth baffles evenly spaced on it, and the fifth vent slots occupy 25%-30% of the area of ​​the fifth diversion zone.

[0019] The second to fifth diversion zones are all strip-shaped; the number of ventilators in the second to fifth diversion zones increases sequentially, and the length of the ventilators increases sequentially; the second to fifth ventilators are staggered along the diameter of the main body of the disc; each second baffle corresponds to a third baffle along the diameter; each third baffle corresponds to a fourth baffle along the diameter, and each fourth baffle corresponds to a fifth baffle along the diameter.

[0020] Furthermore, the second diversion zone is provided with n second vent slots and n second baffles, the third diversion zone is provided with 2n third vent slots and 2n third baffles, the fourth diversion zone is provided with 4n fourth vent slots and 4n fourth baffles, and the fifth diversion zone is provided with 8n fifth vent slots and 8n fifth baffles; wherein n = 5, 6, or 7.

[0021] Furthermore, the top angle α of the first guide cone is 155°-175°.

[0022] Furthermore, the feature is that the diameter of the first vent hole is 1.5mm-2mm.

[0023] Furthermore, a first fixing area is provided between the fourth and fifth diversion areas. The first fixing area is provided with a plurality of first fixing holes for fixing the intermediate diversion device to the coating vacuum chamber. The first fixing holes are offset from the fourth baffle along the diameter direction of the intermediate diversion device.

[0024] Furthermore, the second baffle is inclined, with the end connected to the third diversion zone being higher than the end connected to the first diversion zone. The upper surfaces of the third, fourth, and fifth diversion zones are on the same plane and are higher than the upper surface of the first diversion zone.

[0025] Furthermore, the four diffuser blades of the side splitter, except for the circumference, all extend upwards with several raised edges to form four diffusion channels;

[0026] The center lines of the four diffusion channels correspond to the four positions of the front and rear corners and the center of the cavity, respectively; there is a gap of 0.8-1.5mm between the upper surface of the protruding edge and the bottom of the cavity cover;

[0027] The diffuser section has a diffuser zone in the middle, and a conical third guide cone is provided at the center of the diffuser zone. Several third vent holes are provided between the third guide cone and the edge of the diffuser zone.

[0028] The flow equalization section consists of four ventilation zones, each with a baffle and a ventilation slot spaced apart. The ventilation zones are located at the angle between two adjacent diffuser blades.

[0029] Furthermore, the area of ​​the ventilation slots in the ventilation zone accounts for 60%-70% of the area of ​​the ventilation zone.

[0030] Furthermore, the four diffuser blades are of the same size, and the four diffuser blades form four included angles between each other. The included angles of the two diffuser blades closer to the middle of the cavity are the smallest, the included angles of the two diffuser blades closer to the edge of the cavity are the largest, and the remaining two included angles are of the same size. The size of the four ventilation zones is proportional to the size of the included angle area of ​​the corresponding diffuser blade.

[0031] Furthermore, the outer circumference of the four ventilation zones is smaller than the outer circumference of the diffuser blades.

[0032] Furthermore, a second fixing area is provided on the ventilation area, and a second fixing hole for fixing the side splitter is provided on the second fixing area.

[0033] Furthermore, the height of the raised edge is 0.8mm-1.2mm.

[0034] Furthermore, the angle θ of the upper apex of the third guide cone is 165°-175°.

[0035] Furthermore, an air inlet pipe is provided on the side air inlet, and a remote plasma source (RPS), a scrubbing gas inlet, and a special gas inlet are provided on the air inlet pipe, wherein the scrubbing gas inlet is located above the remote plasma source (RPS) and the special gas inlet is located below the remote plasma source (RPS).

[0036] Furthermore, the intermediate splitter, the surrounding splitter, and the side splitter are made of aluminum alloy plates, and all of them have an anti-corrosion film layer on their outer surface.

[0037] The advantages of this invention are as follows: This invention uses a zoned air distribution method, dividing the air distribution box into seven main areas: a central air distribution area, four surrounding air distribution areas, and two side air distribution areas. A central diffuser is installed below the central air distribution area to regulate the overall airflow; surrounding diffusers are installed below the surrounding air distribution areas to diffuse gas to the corners of the cavity; and side diffusers are installed below the side air distribution areas to assist in uniform gas flow around the center and perimeter of the cavity. The central air distribution area and its corresponding diffuser are the largest, followed by the surrounding air distribution areas and their corresponding diffusers, with the side air distribution areas and their corresponding diffusers being the smallest. By setting diffusers of different functions and sizes in each area, mutual supplementation and coordination between areas are achieved, ultimately resulting in uniform air distribution throughout the entire air distribution box, thus solving the problem of uneven air distribution in some areas. Attached Figure Description

[0038] To more clearly illustrate the technical solutions of the embodiments of this utility model, the drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of this utility model and should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0039] Figure 1 This is a diagram showing the location distribution of the seven splitters in this embodiment.

[0040] Figure 2 This is a location distribution diagram of the seven gas distribution zones in this embodiment.

[0041] Figure 3 This is a schematic diagram showing the location of each branching zone of the intermediate branching unit.

[0042] Figure 4 This is a schematic diagram of the intermediate splitter.

[0043] Figure 5 yes Figure 4 Cross-sectional view along AA.

[0044] Figure 6 yes Figure 5 A magnified view of a section at point B in the middle.

[0045] Figure 7 This is a schematic diagram of the structure of the four-sided splitter.

[0046] Figure 8 This is a plan view of the side splitter.

[0047] Figure 9 yes Figure 8 Cross-sectional view along CC.

[0048] Figure 10This is a three-dimensional structural diagram of the side-splitting flow.

[0049] Explanation of key component symbols:

[0050] 1. Cavity cover;

[0051] 2. Central air distribution area; 21. Central air inlet;

[0052] 3. Surrounding air distribution area; 31. Surrounding air intake holes;

[0053] 4. Side air distribution area; 41. Side air inlet;

[0054] 5. Intermediate diverter; 51. First diverting zone; 511. First guide cone; 512. First vent; 52. Second diverting zone; 521. Second vent groove; 522. Second baffle; 53. Third diverting zone; 531. Third vent groove; 532. Third baffle; 54. Fourth diverting zone; 541. Fourth vent groove; 542. Fourth baffle; 55. Fifth diverting zone; 551. Fifth vent groove; 552. Fifth baffle; 56. First fixing zone; 561. First fixing hole;

[0055] 6. Surrounding diverter; 61. Second guide cone; 62. Second vent; 63. Annular vent groove;

[0056] 7. Side splitter; 71. Diffusion section; 711. Diffusion blade; 712. Raised edge; 713. Diffusion channel; 72. Flow equalization section; 721. Ventilation zone; 722. Sixth baffle; 723. Sixth venting groove; 73. Diffusion zone; 731. Third guide cone; 732. Third vent; 74. Third fixing zone; 741. Third fixing hole. Detailed Implementation

[0057] To make the objectives, technical solutions, and advantages of the embodiments of this utility model clearer, the technical solutions of the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this utility model, not all embodiments. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of this utility model.

[0058] In this utility model, unless otherwise stated, directional terms such as "up," "down," "left," and "right" are generally understood in conjunction with the accompanying drawings and the directions shown in actual applications.

[0059] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this utility model, "a plurality of" means two or more, unless otherwise explicitly specified.

[0060] In this utility model, unless otherwise explicitly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact through an intermediate medium. Furthermore, "above," "on top of," and "over" the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0061] The endpoints and any values ​​of the ranges disclosed herein are not limited to the precise ranges or values, and should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of the various ranges, the endpoint values ​​of the various ranges and individual point values, and individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed herein. The terms "optional" and "discretionary" mean that they may or may not be included (or may or may not be present).

[0062] This embodiment discloses a gas distribution system for a PECVD coating cavity, which includes a cavity body and a cavity cover 1. A gas distribution box is disposed inside the cavity body and located below the cavity cover 1. A gas distribution plate is located below the gas distribution box.

[0063] like Figure 2As shown, the gas distribution box is divided into seven circular areas centered on the seven air inlets: a central gas distribution area 2, four peripheral gas distribution areas 3, and two side gas distribution areas 4. The central gas distribution area 2 has the largest area and is located in the center of the cavity cover 1. The central gas distribution area 2 is adjacent to the other six areas, hence its largest area, allowing it to better distribute gas to the other six areas and supplement the gas supply to areas with insufficient gas. The four peripheral gas distribution areas 3 are smaller than the central gas distribution area 2, and are of equal size, located at the four corners of the cavity cover 1, arranged symmetrically in a ring with the center of the central gas distribution area 2 as the symmetrical point. The gas in the four surrounding gas distribution zones 3 is mainly delivered to the four corners of the gas distribution box. Simultaneously, gas is supplied or withdrawn based on the gas volume in the central gas distribution zone 2 and the side gas distribution zones 4. For example, if any of the four surrounding gas distribution zones 3 has a slightly larger intake volume, most of the excess gas is supplied to the central gas distribution zone 2, and a small portion is supplied to the side gas distribution zones 4, and vice versa. The side gas distribution zones 4 have the smallest circular area and are located on the left and right sides of the central gas distribution zone 2. Because these two zones are the most stable, their gas flow is generally self-sufficient, while also providing auxiliary gas to the three adjacent gas distribution zones, acting as an intermediate regulator.

[0064] like Figure 1 As shown, a central air inlet 21 is located at the center of the central air distribution zone 2, and a central diffuser 5 for regulating the overall airflow is located below the central air inlet 21. A peripheral air distribution zone 3 has peripheral air inlets 31 at its center. A peripheral diffuser 6 for diffusing gas to the corners of the cavity is located below the peripheral air inlets 31. A side air inlet 41 is located at the center of the side air distribution zone 4. A side diffuser 7 for assisting in the uniform flow of gas in the center and around the perimeter of the cavity is located below the side air inlets 41.

[0065] The central distributor 5 and the four peripheral distributors 6 are arranged in a radial shape, and the gaps between their radial strips can be adjusted according to different process formulations. The side distributors 7 include a diffuser 71 for outward flow distribution and a flow equalization section 72 for downward flow distribution. The diffuser 71 is X-shaped and has four diffusion channels 713. There is a gas sending and receiving relationship between the distributors, and adjacent distributors cooperate with each other in gas distribution.

[0066] Specifically:

[0067] like Figures 3 to 6As shown, the intermediate distributor 5 includes a disc body with five distribution zones arranged sequentially from the center outwards: the first distribution zone 51, the second distribution zone 52, the third distribution zone 53, the fourth distribution zone 54, and the fifth distribution zone 55. Several ventilation slots and baffles are alternately distributed on the five distribution zones, with the ventilation slots radiating outwards from the center. When gas enters through the inlet, most of it is blocked by the baffles and diffuses outwards along the baffles. The gas flows along the radial strip baffles towards the edge of the distributor. During the flow, some gas flows down from both sides of the strip baffles, thus achieving gas diversion and uniform flow while preventing excessive gas concentration in the central area.

[0068] The first diversion zone 51 is the first guide cone 511. Through comparative experiments, it was found that the diffusion effect is better when the top angle α of the first guide cone 511 is between 155° and 175°. Several first vent holes 512 are provided on the first guide cone 511, with the holes arranged in a ring. The purpose of these first vent holes 512 is to allow a small portion of the airflow to pass through and enter the lower part of the diverter. After multiple experiments, the optimal diameter of the first vent holes is found to be 1.5mm-2mm. A diverter without first vent holes 512 was also compared, and it was found that the diversion effect of the diverter was slightly reduced. The conclusion is that the center should not be completely blocked; first vent holes 512 are necessary to allow gas to pass through.

[0069] The second diversion zone 52 has several second venting slots 521 and second baffles 522 evenly distributed at intervals. The second venting slots 521 occupy 30%-35% of the area of ​​the second diversion zone 52. The second baffles 522 are inclined, meaning the end connecting to the third diversion zone 53 is higher than the end connecting to the first diversion zone 51. The upper surfaces of the third diversion zone 53, fourth diversion zone 54, and fifth diversion zone 55 are on the same plane and are higher than the upper surface of the first diversion zone 51. When gas impacts the first diversion zone 51, the gas pressure is high, and the gas will rebound upwards. The inclined arrangement of the second baffles 522 ensures that the upper planes of the third diversion zone 53, fourth diversion zone 54, and fifth diversion zone 55 are higher than the first diversion zone 51, matching the rebounding gas and facilitating its diffusion to distant locations.

[0070] Several third venting slots 531 and third baffles 532 are evenly distributed on the third diversion zone 53. The third venting slots 531 occupy 25%-30% of the area of ​​the third diversion zone 53.

[0071] Several fourth venting slots 541 and fourth baffles 542 are evenly distributed on the fourth diversion zone 54. The fourth venting slots 541 occupy 30%-35% of the area of ​​the fourth diversion zone 54.

[0072] Several fifth venting slots 551 and fifth baffles 552 are evenly distributed on the fifth diversion zone 55. The fifth venting slots 551 occupy 25%-30% of the area of ​​the fifth diversion zone 55.

[0073] The ventilation slots in the second and third diversion zones 52 and 53 are arranged in a large-small-large-small pattern, which helps the gas entering from the ventilation slots to complement and evenly distribute during gas diffusion. The proportion of ventilation slots is smaller than that of baffles, allowing most of the gas to diffuse further along the baffles.

[0074] The second to fifth diversion zones 52 and 55 are all annular. The number of ventilation slots in the second to fifth diversion zones 52 and 55 increases sequentially, becoming denser and longer. Different proportions of ventilation slots are designed according to the experimental setup to ensure more uniform gas distribution. When designing the positions of the baffles in each diversion zone, the baffles are positioned as close as possible to each other, which helps the gas diffuse to areas farther from the inlet, overcoming the problem of thin gas at the corners of the coating chamber. Specifically, the second diversion zone 52 has n second ventilation slots 521 and n second baffles 522; the third diversion zone 53 has 2n third ventilation slots 531 and 2n third baffles 532; the fourth diversion zone 54 has 4n fourth ventilation slots 541 and 4n fourth baffles 542; and the fifth diversion zone 55 has 8n fifth ventilation slots 551 and 8n fifth baffles 552; where n = 5, 6, or 7. In this embodiment, n=5. The second diversion zone 52 is provided with 5 second venting slots 521 and 5 second baffles 522; the third diversion zone 53 is provided with 10 third venting slots 531 and 10 third baffles 532; the fourth diversion zone 54 is provided with 20 fourth venting slots 541 and 20 fourth baffles 542; and the fifth diversion zone 55 is provided with 40 fifth venting slots 551 and 40 fifth baffles 552. The number of baffles increases exponentially from the inside out, such that each second baffle 522 corresponds to one third baffle 532 along its diameter; each third baffle 532 corresponds to one fourth baffle 542 along its diameter; and each fourth baffle 542 corresponds to one fifth baffle 552 along its diameter. This helps to ensure that enough gas can diffuse far along the baffle, while some gas also enters the lower part of the distributor from the vent slot. At the same time, the second vent slot 521 to the fifth vent slot 551 are staggered along the diameter of the disk body, making the gas entering the lower part of the distributor more uniform.

[0075] To better fix the flow divider, a first fixing area 56 is provided between the fourth flow divider 54 and the fifth flow divider 555. The fixing area is provided with a number of first fixing holes 561 for fixing to the coating vacuum chamber. In order to prevent the fixing holes from affecting the gas diffusion to the far end along the baffle, the fixing holes are staggered from the fourth baffle 542 along the diameter direction.

[0076] The intermediate distributor 5 is divided into five distribution zones. Each zone has alternating vents and baffles, radiating outwards from the center. This allows gas entering from the inlet to encounter the first distribution zone 51, where it is radially distributed outwards by the conical disc. Simultaneously, a small portion of the gas enters the distribution box directly below the distributor through the first vent 512. Most of the gas is blocked by the baffles and diffuses outwards, flowing along the radial strip baffles towards the edge of the distributor. During this flow, some gas also flows down from both sides of the strip baffles, thus achieving gas distribution and uniform flow while preventing excessive concentration of gas in the central area.

[0077] Meanwhile, based on the gas flow pattern, the number of ventilation slots in each diversion zone of the intermediate diverter 5 increases sequentially from the center outwards, becoming denser and longer. Different proportions of ventilation slots are designed according to the experimental setup to ensure more uniform gas distribution. When designing the positions of the baffles in each diversion zone, the baffles are positioned as close as possible to each other, which helps the gas diffuse to areas farther from the inlet, overcoming the problem of thin gas at the corners of the coating chamber.

[0078] Specifically:

[0079] like Figure 7 As shown, the area of ​​the four corner distributors 6 is smaller than that of the central distributor 5. Experiments have verified that when the area of ​​the central distributor 5 is 1.4-1.6 times that of the four corner distributors 6, the gas uniformity effect is better. The structure of the four corner distributors 6 is similar to that of the central distributor 5, adopting a layered radial structure. A second guide cone 61 is set in the middle, and a second vent 62 is set around the second guide cone 61. On the outermost layer of the four corner distributors 6, an annular vent groove 63 is added as an airflow circulation ring. The setting of the annular vent groove 63 allows the gas to be accelerated and diverted downward after being delivered to the edge. Gas usually tends to gather at the edge, and the groove at this point is conducive to better gas diversion. The gas distributors at the four corners divert less gas to the central area, while the gas distributors in the central area divert more gas to the four corners. Therefore, the central area distributors do not have through slots along their edges to allow the gas to diffuse better in all directions. The four corner distributors need to ensure their own gas distribution first, so through slots are designed at their edges to accelerate the downward flow of gas for better distribution.

[0080] Specifically:

[0081] like Figures 8 to 10As shown, the side diffuser 7 includes a diffuser 71 for distributing the flow outwards and a flow equalization section 72 for distributing the flow downwards. The diffuser 71 is X-shaped and has four identical diffuser blades 711. Each of the four diffuser blades 711, except for the circumference, has several raised edges 712 extending upwards, forming four diffusion channels 713. The centerlines of the four diffusion channels 713 correspond to four positions at the front and rear corners and the center of the cavity, respectively. The four diffusion channels 713 distribute the gas in the central region to the surrounding areas, especially the region far from the inlet, thereby solving the problem of sparse plasma at the corners of the cavity.

[0082] The raised edge 712 has a height of 0.8mm-1.2mm, and there is a gap of 0.8-1.5mm between the upper surface of the raised edge 712 and the bottom of the cavity cover. This gap allows a portion of the gas in the middle region to enter the flow equalization section 72 and flow downwards. The gas in the diffusion channel 713 and the flow equalization section 72 work together to achieve a stable flow distribution and improve the uniformity of the gas within the cavity.

[0083] The flow equalization section 72 comprises four ventilation zones 721. Each ventilation zone 721 is provided with a sixth baffle 722 and a sixth ventilation groove 723 at intervals. The ventilation zones 721 are located at the angle between two adjacent diffuser blades 711. The outer circumference of each of the four ventilation zones 721 is smaller than the outer circumference of each diffuser blade 711. The area of ​​the sixth ventilation groove 723 on each ventilation zone 721 occupies 60%-70% of the area of ​​a single ventilation zone 721. In this embodiment, the four diffuser blades 711 form four angles between each pair of diffuser blades. The angles are smallest for the two diffuser blades 711 closest to the center of the cavity, largest for the two diffuser blades 711 closest to the corners of the cavity, and the remaining two angles are of equal size. The size of each of the four ventilation zones 721 is proportional to the size of the angle between the corresponding diffuser blades 711. The largest ventilation zone 721 has five sixth ventilation grooves 723, while the remaining ventilation zones 721 have three sixth ventilation grooves 723. Setting the number and size of ventilation slots appropriately is more conducive to the uniform distribution of downward-flowing gas.

[0084] As shown in the figure, a diffusion zone 73 is provided in the middle of the diffuser section 71. A conical third guide cone 731 is provided at the center of the diffusion zone 73. The third guide cone 731 is designed to facilitate the downward flow of the incoming gas along the side of the cone, thereby distributing it to the surrounding area more quickly. Several third vent holes 732 are provided between the third guide cone 731 and the edge of the diffusion zone 73, allowing a small amount of gas to enter the area directly below the distributor through the vent holes. The angle θ of the upper apex of the third guide cone 731 is 165°-175°.

[0085] By designing the gap size and the proportion of the ventilation slots in the ventilation zone 721, the optimal range was selected through experiments, which greatly improved the gas uniformity and thus improved the film quality of the coated products.

[0086] The ventilation zone 721 is provided with a third fixing zone 74, and the third fixing zone 74 is provided with a third fixing hole 741 for fixing the side distributor 7.

[0087] The side air inlet 41 serves not only as the inlet for coating gas but also as the inlet for plasma cleaning gas. An inlet pipe is installed on the side air inlet 41, which includes a remote plasma source (RPS), a cleaning gas inlet, and a special gas inlet. The cleaning gas inlet is located above the RPS, and the special gas inlet is located below it. When coating gas is required, it enters through the special gas inlet; when plasma cleaning gas is required, it enters through the cleaning gas inlet.

[0088] The side distributor 7 increases the uniformity of gas distribution by distributing gas from the central area to the surrounding areas. By combining a diffuser 71 and a flow equalizer 72, the gas entering from the pipe inlet is divided into two parts by the side distributor 7. One part diffuses outward from the diffusion channel 713 of the diffuser 71 to the far corner of the cavity, while the other part enters the ventilation area 721 of the flow equalizer 72 through the gap between the raised edge 712 and the cavity cover, flowing downwards evenly. The two parts of gas work together to achieve a stable flow distribution and improve the uniformity of gas within the cavity. By designing the gap size, the width of the diffuser channel 713, and the proportion of the ventilation slot in the ventilation area 721, the optimal range was selected through experiments, greatly improving gas uniformity, thereby improving the film quality of the coated products and accelerating the cleaning efficiency of the cavity.

[0089] During the cleaning of the coating chamber, the cleaning gas is ionized into cleaning plasma by the RPS and enters from the cleaning gas inlet. The cleaning gas is evenly distributed to various areas of the chamber by the side distributor 7, which not only improves the cleaning quality but also reduces the cleaning time and speeds up the cleaning efficiency of the chamber.

[0090] Among them, the central diverter 5, the surrounding diverter 6, and the side diverter 7 are all aluminum alloy diverters. Aluminum alloy is lightweight and strong, thus reducing the overall weight of the diverter. The outer surface of the diverter is coated with an anti-corrosion film to improve its service life. At the same time, the manufacturing cost is not high and it is easy to process.

[0091] During coating gas intake, the special gas enters the cavity simultaneously through seven air inlets. After entering the central gas distribution zone 2 through the air inlets, the gas is radially distributed to the surrounding areas by the action of the first guide cone 511. Simultaneously, a small portion of the gas enters the gas distribution box directly below the central distributor 5 through the first vent 512. A portion of the gas enters the areas below the central gas distribution zone 2 through the venting grooves on both sides of the baffle, while another portion is blocked by the baffle and diffuses outwards, replenishing the side gas distribution zones 4 and the surrounding gas distribution zones 3. After entering the side gas distribution zone 4 through the air inlets, a portion of the gas diffuses outwards to the far corners of the cavity through the diffusion channel 713 of the diffuser 71, balancing the gas in the surrounding gas distribution zones 3 and the central gas distribution zone 2. Another portion of the gas enters the venting area 721 of the flow equalization section 72 through the gap between the protruding edge 712 and the cavity cover, flowing downwards and into the areas below the side gas distribution zone 4. The surrounding air distribution zone 3 receives gas from the inlet and, under the action of the second guide cone 61, distributes it radially in all directions. Simultaneously, a small portion of the gas enters the air distribution box directly below the central distributor 5 through the first vent 512. Some gas enters the areas below the central air distribution zone 2 through the venting grooves on both sides of the baffle, while some gas is blocked by the baffle and diffuses outwards, accelerating downwards at the edge of the outermost annular venting groove 63 to replenish the gas in the corner areas of the cavity. The adjacent areas of the central air distribution zone 2, the side air distribution zone 4, and the surrounding air distribution zone 3, according to the laws of airflow, achieve mutual supplementation and uniform gas distribution between the areas, ultimately resulting in a uniform gas distribution throughout the entire air distribution box.

[0092] The preferred embodiments of this utility model have been described in detail above; however, this utility model is not limited thereto. Within the scope of the technical concept of this utility model, various simple modifications can be made to the technical solution of this utility model, including combining the various technical features in any other suitable manner. These simple modifications and combinations should also be considered as the content disclosed by this utility model and are all within the protection scope of this utility model.

Claims

1. A gas distribution system for a PECVD coating chamber, comprising a chamber body and a chamber cover, wherein a gas distribution box is disposed inside the chamber body and located below the chamber cover; and a gas distribution plate is located below the gas distribution box. Its features are: The gas distribution box includes a central gas distribution area, four surrounding gas distribution areas, and two side gas distribution areas. The surrounding gas distribution areas are located at the four corners of the cavity cover and are symmetrically distributed in a ring with the center of the central gas distribution area as the symmetrical point. The side gas distribution areas are located on the left and right sides of the central gas distribution area, respectively. The area of ​​the central gas distribution area, the surrounding gas distribution areas, and the side distribution areas decreases sequentially. The intermediate air distribution zone has an intermediate air inlet at its center, and an intermediate flow divider for regulating the overall airflow is located below the intermediate air inlet. The intermediate flow divider has an upward-protruding first guide cone at its center, and several radially arranged strip-shaped ventilation slots and baffles around it. A four-sided air inlet is provided at the center of the four-sided air distribution area; a four-sided diffuser is provided below the four-sided air inlet for diffusing gas to the corners of the cavity; a second upward-protruding guide cone is provided at the center of the four-sided diffuser, and several strip-shaped ventilation grooves and baffles are provided around it in a radially alternating pattern, with an annular ventilation groove provided on the outermost ring. A side air inlet is provided at the center of the side air distribution area; below the side air inlet is a side flow divider for uniform gas flow in the center and around the auxiliary cavity; the side flow divider includes a diffuser for diverting gas to the surrounding areas and a flow equalization section for diverting gas downwards; the diffuser is "X" shaped and has four diffusion channels. The upper surface area of ​​the middle splitter, the surrounding splitter, and the side splitter decreases sequentially.

2. The gas equalization system applied to a PECVD coating cavity according to claim 1, characterized in that: Both the intermediate splitter and the surrounding splitter are disc-shaped, and the area of ​​the intermediate splitter is 1.4-1.6 times the area of ​​the surrounding splitter.

3. The gas equalization system applied to a PECVD coating cavity according to claim 2, characterized in that: The intermediate distributor includes a disk body, and the disk body has the following components distributed sequentially from the center to the periphery: The first diversion zone, the first guide cone is located in the first diversion zone, and the first guide cone is provided with a plurality of first vent holes; The second diversion zone has several second vent slots and second baffles evenly distributed on it, and the second vent slots occupy 30%-35% of the area of ​​the second diversion zone; The third diversion zone has a plurality of third vent slots and third baffles evenly distributed on it, and the third vent slots occupy 25%-30% of the area of ​​the third diversion zone; The fourth diversion zone is provided with a number of fourth vent slots and fourth baffles evenly spaced on it, and the fourth vent slots occupy 30%-35% of the area of ​​the fourth diversion zone. The fifth diversion zone is provided with a plurality of fifth vent slots and fifth baffles evenly spaced on it, and the fifth vent slots occupy 25%-30% of the area of ​​the fifth diversion zone. The second to fifth diversion zones are all strip-shaped; the number of ventilators in the second to fifth diversion zones increases sequentially, and the length of the ventilators increases sequentially; the second to fifth ventilators are staggered along the diameter of the main body of the disc; each second baffle corresponds to a third baffle along the diameter; each third baffle corresponds to a fourth baffle along the diameter, and each fourth baffle corresponds to a fifth baffle along the diameter.

4. The gas equalization system applied to a PECVD coating cavity according to claim 3, characterized in that: The second diversion zone is provided with n second vent slots and n second baffles, the third diversion zone is provided with 2n third vent slots and 2n third baffles, the fourth diversion zone is provided with 4n fourth vent slots and 4n fourth baffles, and the fifth diversion zone is provided with 8n fifth vent slots and 8n fifth baffles; where n = 5, 6, or 7.

5. The gas uniformity system applied to a PECVD coating cavity according to claim 3, characterized in that: The top angle α of the first guide cone is 155°-175°.

6. The gas equalization system applied to a PECVD coating cavity according to claim 3, characterized in that: The diameter of the first vent is 1.5mm-2mm.

7. The gas equalization system applied to a PECVD coating cavity according to claim 3, characterized in that: A first fixing area is provided between the fourth and fifth diversion areas. The first fixing area is provided with a plurality of first fixing holes for fixing the intermediate diversion device to the coating vacuum chamber. The first fixing holes are offset from the fourth baffle along the diameter direction of the intermediate diversion device.

8. The gas equalization system applied to a PECVD coating cavity according to claim 3, characterized in that: The second baffle is inclined, with the end connected to the third diversion zone being higher than the end connected to the first diversion zone. The upper surfaces of the third, fourth, and fifth diversion zones are on the same plane and are higher than the upper surface of the first diversion zone.

9. The gas uniformity system applied to a PECVD coating cavity according to claim 2, characterized in that: The four diffuser blades of the side splitter, except for the circumference, all extend upwards with several raised edges to form four diffusion channels. The center lines of the four diffusion channels correspond to the four positions of the front and rear corners and the center of the cavity, respectively; there is a gap of 0.8-1.5mm between the upper surface of the protruding edge and the bottom of the cavity cover; The diffuser section has a diffuser zone in the middle, and a conical third guide cone is provided at the center of the diffuser zone. Several third vent holes are provided between the third guide cone and the edge of the diffuser zone. The flow equalization section consists of four ventilation zones, each with a baffle and a ventilation slot spaced apart. The ventilation zones are located at the angle between two adjacent diffuser blades.

10. The gas uniformity system applied to a PECVD coating cavity according to claim 9, characterized in that: The area of ​​the ventilation slots in the ventilation zone accounts for 60%-70% of the area of ​​the ventilation zone.

11. The gas uniformity system applied to a PECVD coating cavity according to claim 9, characterized in that: The four diffuser blades are of the same size, and the four diffuser blades form four angles between each other. The two diffuser blades closer to the middle of the cavity have the smallest angles, the two diffuser blades closer to the edge of the cavity have the largest angles, and the remaining two angles are of the same size. The size of the four ventilation zones is proportional to the size of the corresponding diffuser blade angle region.

12. The gas equalization system applied to a PECVD coating cavity according to claim 9, characterized in that: The outer circumference of the four ventilation zones is smaller than the outer circumference of the diffuser blades.

13. The gas uniformity system applied to a PECVD coating cavity according to claim 9, characterized in that: The ventilation area is provided with a second fixing area, and the second fixing area is provided with a second fixing hole for fixing the side splitter.

14. The gas uniformity system applied to a PECVD coating cavity according to claim 9, characterized in that: The height of the raised edge is 0.8mm-1.2mm.

15. The gas uniformity system applied to a PECVD coating cavity according to claim 9, characterized in that: The angle θ of the top of the third guide cone is 165°-175°.

16. The gas equalization system applied to a PECVD coating cavity according to claim 2, characterized in that: An air inlet pipe is provided on the side air inlet, and a remote plasma source (RPS), a scrubbing gas inlet, and a special gas inlet are provided on the air inlet pipe. The scrubbing gas inlet is located above the remote plasma source (RPS), and the special gas inlet is located below the remote plasma source (RPS).

17. The gas equalization system applied to a PECVD coating cavity according to claim 9, characterized in that: The middle splitter, the surrounding splitter, and the side splitter are all made of aluminum alloy plates, and their outer surfaces are all covered with an anti-corrosion film.

Images