Chemical vapor deposition equipment suitable for barrel-shaped workpiece

Abstract

The utility model discloses chemical vapor deposition equipment suitable for barrel-shaped workpieces, which comprises a furnace body, a thermal insulation layer, a deposition space, a heater, an air injection system and an exhaust system, the deposition space and the heater are arranged in the thermal insulation layer, and the furnace body comprises a furnace shell and a furnace cover; the thermal insulation layer comprises an outer thermal insulation layer and an inner thermal insulation layer which are combined to form a deposition space; the air injection system comprises an outer circumference air inflation set, an outer bottom air inflation set, an inner circumference air inflation set, an inner bottom air inflation set and an air inlet controller, wherein the air inlet controller is communicated with all the air inflation sets through air pipes and controls the air inlet flow of all the air inflation sets. The inner thermal insulation layer and the outer thermal insulation layer of the chemical vapor deposition equipment can be independently replaced as required. Besides, the gas injection system comprises a plurality of gas inflation sets arranged on the circumferential side face of the furnace shell, the bottom of the furnace shell, the side wall of the inner heat preservation layer and the bottom of the inner heat preservation layer, process gas is conveyed to the inner surface and the outer surface of the barrel-shaped workpiece at the same time, uniform deposition of the inner surface and the outer surface of the barrel-shaped workpiece is guaranteed, and the deposition quality of the whole workpiece is guaranteed.

Description

Technical Field

[0001] The utility model relates to the technical field of silicon carbide semiconductors, in particular to a chemical vapor deposition device suitable for barrel-shaped workpieces. Background Art

[0002] Chemical vapor deposition (CVD) is a thin film deposition technology that utilizes a gaseous substance to react chemically on a solid surface, forming a solid substance that is then deposited on the workpiece. It is widely used in cutting tool materials, wear-resistant, heat-resistant, and corrosion-resistant materials, specialized composite materials for the aerospace industry, nuclear reactor materials, and biomedical materials. It is also essential for the thin film deposition of ferroelectric, insulating, magnetic, and optoelectronic materials used in large-scale integrated circuit technology.

[0003] Existing chemical vapor deposition equipment typically includes a furnace body, an insulation layer disposed within the furnace body, a deposition chamber and heater within the insulation layer, and an air injection system and exhaust system for supplying process gas to the deposition chamber. A workpiece is placed in the deposition chamber, and process gas is introduced into the sealed chamber. The heater heats the chamber to the required process temperature. At this point, the gas containing the required elements reacts on the workpiece surface and gradually deposits to form a thin film, while the remaining byproducts are promptly discharged from the deposition chamber. Throughout the deposition process, in addition to factors such as temperature and pressure, the flow rate of the process gas, its distribution within the deposition chamber, and its flow path directly affect the deposition rate and the quality of the film on the workpiece surface. In conventional chemical vapor deposition equipment, the air injection system is typically located on the outer wall of the deposition chamber. For barrel-shaped workpieces with only one end open, the inner surface cannot receive sufficient process gas flow. This results in uneven deposition and inconsistent film thickness on the inner and outer surfaces of the barrel-shaped workpiece, seriously affecting the deposition quality of the barrel-shaped workpiece.

[0004] Chinese patent application CN108060409A discloses a deposition chamber and chemical vapor deposition system suitable for annular workpieces. By providing a cylindrical inner insulation layer, the chamber significantly reduces the volume of the heated space within the annular workpiece, significantly reducing heating energy consumption. However, the inner and outer insulation layers frequently require replacement, requiring the heater to be removed, which is very inconvenient. Furthermore, the heater, exposed within the deposition space, can easily contaminate the process gas, thereby affecting the workpiece deposition quality. Utility Model Content

[0005] The technical problem to be solved by the present utility model is that in the prior art, when the chemical vapor deposition equipment performs deposition processing on a barrel-shaped workpiece, the flow rate of the process gas on the inner and outer walls is inconsistent, resulting in defects in the deposition quality of the barrel-shaped workpiece, and the unreasonable setting of the insulation layer in the equipment makes it inconvenient to replace the insulation layer. The utility model provides a chemical vapor deposition equipment suitable for barrel-shaped workpieces, which can ensure that the process gas flows evenly to the inner and outer surfaces of the barrel-shaped workpiece, and can also quickly and conveniently replace the insulation layer.

[0006] The technical solution to the technical problem of the utility model is: construct a chemical vapor deposition equipment suitable for barrel-shaped workpieces, including a furnace body, a thermal insulation layer, a deposition space and a heater arranged in the thermal insulation layer, an air injection system and an exhaust system, the furnace body includes a furnace shell with an open top and a furnace cover covering the open part of the furnace shell; the thermal insulation layer includes an outer thermal insulation layer arranged in close contact with the inner side wall and the inner bottom of the furnace shell, an inner thermal insulation layer arranged at the bottom of the furnace cover and protruding toward the inner center of the outer thermal insulation layer, the outer thermal insulation layer and the inner thermal insulation layer are combined to form the deposition space; the air injection system includes a furnace shell evenly fixedly arranged on the furnace shell An outer circumferential inflation group which is arranged on the circumferential side and passes through the side wall of the outer insulation layer and extends into the deposition space, an outer bottom inflation group which is arranged at the bottom of the furnace shell and passes through the bottom of the outer insulation layer and extends into the deposition space, an inner circumferential inflation group which is arranged on the furnace cover and passes through the side wall of the inner insulation layer and extends into the deposition space, an inner bottom inflation group which is arranged on the furnace cover and passes through the bottom of the inner insulation layer and extends into the deposition space, and an air intake controller which is connected with the outer circumferential inflation group, the outer bottom inflation group, the inner circumferential inflation group and the inner bottom inflation group respectively through air pipes and controls the air intake flow rate of each inflation group.

[0007] Furthermore, the inner insulation layer includes an inner insulation barrel fixed at the center position of the bottom of the furnace cover and a top insulation ring fixed around the bottom of the furnace cover. When the furnace cover covers the opening of the furnace shell, the inner insulation barrel protrudes toward the inner center position of the outer insulation layer, and the top insulation ring seals the gap between the outer insulation layer and the inner insulation barrel; it can prevent the metal furnace cover from contaminating the process gas in the deposition, and facilitate the replacement of the inner insulation layer in different areas.

[0008] Furthermore, a center hole is provided in the center of the furnace cover and raised portions extending toward the furnace shell are provided around the bottom. An inner insulating barrel is fixed at the center hole of the furnace cover, the inner insulation barrel is sleeved on the outside of the inner insulation barrel, and the top insulation ring is embedded between the inner insulation barrel and the raised portion of the furnace cover; the inner insulation barrel is conveniently fixed to the bottom of the furnace cover through the inner insulation barrel, and the top insulation ring is conveniently fixed to the bottom of the furnace cover through the raised portion of the furnace shell.

[0009] Furthermore, the inner circumferential inflation group includes a plurality of inner air guide rings fixedly arranged at different vertical positions on the inner wall of the inner isolation barrel, an inner air guide pipe passing through the top of the furnace cover to connect the external air pipe with the inner air guide ring, and inner air nozzles evenly distributed on the inner air guide ring. The inner air nozzles pass through the inner air guide ring, the inner isolation barrel and the inner insulation barrel to connect the deposition space with the inner air guide ring; it is convenient to connect the inner air nozzle located on the side wall of the inner insulation barrel with the external air pipe of the furnace cover, and the process gas can be introduced into the side wall of the inner insulation barrel from the top of the furnace cover, avoiding frequent disassembly of the inner isolation barrel to connect the air pipe.

[0010] Furthermore, the inner air nozzle includes a hollow tubular portion and a head arranged at one end of the tubular portion, a seal is provided between the head and the inner air guide ring, the outer circumferential surface of the tubular portion is provided with a threaded section that cooperates with the inner isolation barrel, and the tubular portion is provided with connecting holes evenly distributed around the circumference corresponding to the inner air guide ring; the inner air nozzle and the inner air guide ring are conveniently and quickly fixed to the side wall of the inner isolation barrel, the inner air nozzle can not only introduce the process gas in the inner air guide ring into the deposition space through the connecting hole, but also serve as a fastener to fix the inner air guide ring to the inner isolation barrel.

[0011] Furthermore, the inner bottom inflation group includes a plurality of concentrically arranged inner bottom air guide rings fixedly arranged on the inner bottom of the inner isolation barrel, an inner bottom air guide pipe passing through the top of the furnace cover to connect the external air pipe with the inner bottom air guide ring, and an inner bottom air nozzle evenly distributed on the inner bottom air guide ring. The inner bottom air nozzle passes through the inner bottom air guide ring, the inner isolation barrel and the inner insulation barrel to connect the deposition space with the inner bottom air guide ring; it is convenient to connect the inner bottom air nozzle located at the bottom of the inner insulation barrel with the external air pipe of the furnace cover, and the process gas can be introduced into the bottom of the inner insulation barrel from the top of the furnace cover, avoiding frequent disassembly of the inner isolation barrel to connect the air pipe.

[0012] Furthermore, the inner bottom air nozzle includes a hollow tubular portion and a head portion arranged at one end of the tubular portion, a seal is provided between the head portion and the inner bottom air guide ring, the outer circumferential surface of the tubular portion is provided with a threaded section that cooperates with the inner isolation barrel, and the tubular portion is provided with connecting holes evenly distributed around the circumference corresponding to the inner bottom air guide ring; the inner bottom air nozzle and the inner bottom air guide ring are conveniently and quickly fixed to the side wall of the inner isolation barrel.

[0013] Furthermore, the exhaust system includes an exhaust channel arranged between the top insulation ring and the inner insulation barrel and an exhaust pipe arranged on the furnace cover. An exhaust port corresponding to the exhaust pipe is provided in the exhaust channel, and a plurality of exhaust holes are evenly distributed on the circumference of the top insulation ring to connect the deposition space to the exhaust channel.

[0014] Furthermore, an outer insulating tube is provided between the outer insulating layer and the side wall of the inner insulating barrel, a sealed heating chamber is provided between the outer insulating tube and the outer insulating layer, and the heater is arranged in the heating chamber; the heater is prevented from contaminating the process gas and the deposition quality is ensured.

[0015] Furthermore, the outer circumferential inflation group includes an outer air duct fixed on the circumferential side of the furnace shell, and an outer air nozzle passing through the side wall of the outer isolation tube and the side wall of the outer insulation layer. One end of the outer air nozzle is inserted into the outer air duct and the other end is fixed on the side wall of the outer isolation tube and extends into the deposition space; so that the two ends of the outer air nozzle can be stably and reliably positioned on the furnace shell and the outer isolation tube respectively.

[0016] Furthermore, the outer bottom inflation group includes an outer bottom air nozzle passing through the bottom of the outer shell and the bottom of the outer insulation layer, one end of the outer bottom air nozzle is inserted into the outer bottom air guide pipe and the other end is fixed to the bottom of the outer isolation tube and extends into the deposition space; so that the two ends of the outer bottom air nozzle are stably and reliably positioned on the furnace shell.

[0017] The chemical vapor deposition equipment for barrel-shaped workpieces described in the present invention has the following beneficial effects: by dividing the insulation layer into an outer insulation layer disposed within the furnace shell and an outer insulation layer disposed at the bottom of the furnace cover and protruding toward the center of the outer insulation layer, a deposition space that matches the barrel-shaped workpiece is formed, resulting in a compact space and no waste of process gas; the inner and outer insulation layers can also be replaced independently as needed. Furthermore, by providing an air injection system comprising an outer circumferential gas charging group, an outer bottom gas charging group, an inner circumferential gas charging group, and an inner bottom gas charging group, respectively disposed on the circumferential side of the furnace shell, the bottom of the furnace shell, the sidewall of the inner insulation layer, and the bottom of the inner insulation layer, process gas is simultaneously delivered to the inner and outer surfaces of the barrel-shaped workpiece, ensuring uniform deposition on both inner and outer surfaces and guaranteeing the deposition quality of the entire workpiece. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 Shown is a schematic diagram of the overall structure of a preferred embodiment of the chemical vapor deposition equipment for barrel-shaped workpieces according to the present invention;

[0019] Figure 2 It is a structural schematic diagram of the furnace cover part in a preferred embodiment of the chemical vapor deposition equipment for barrel-shaped workpieces of the present invention;

[0020] Figure 2a Shown Figure 2 An enlarged view of part I;

[0021] Figure 3 It is a structural schematic diagram of the furnace shell part in a preferred embodiment of the chemical vapor deposition equipment for barrel-shaped workpieces of the present invention;

[0022] Figure 3a Shown Figure 3 Enlarged view of Part II. DETAILED DESCRIPTION

[0023] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative labor.

[0024] It should also be noted that the terms "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0025] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art in the art of the present invention. The terms used herein in the specification of the present invention are only for the purpose of describing specific embodiments and are not intended to limit the present invention.

[0026] like Figure 1 、 2As shown in Figures 3 and 4, in a preferred embodiment of the chemical vapor deposition equipment suitable for barrel-shaped workpieces described in the present invention, it mainly includes a furnace body 10, a thermal insulation layer 20, a deposition space 1 and a heater 2 arranged in the thermal insulation layer 20, an injection system, and an exhaust system. The furnace body 10 is preferably configured to include a furnace shell 11 with an opening 11a at the top and a furnace cover 12 covering the furnace shell opening 11a, and the furnace cover 12 forms a closed space after covering the furnace shell 11. The thermal insulation layer 20 includes an outer thermal insulation layer 21 and an inner thermal insulation layer 22, wherein the outer thermal insulation layer 21 is tightly arranged on the inner side wall and inner bottom of the furnace shell 11, and the inner thermal insulation layer 22 is arranged at the bottom of the furnace cover 12 and protrudes from the inner center of the outer thermal insulation layer 21. The inner thermal insulation layer 22 and the outer thermal insulation layer 21 are combined to form a deposition space 1 that matches the barrel-shaped workpiece 3. The air injection system includes an outer circumferential air group 50, an outer bottom air group 60, an inner circumferential air group 70, and an inner bottom air group 80. Each air group is connected to an air inlet controller 31, which controls the air flow rate of each air group according to actual process requirements. The outer circumferential air group 50 is arranged on the circumferential side of the furnace shell 11 and extends through the side wall of the outer insulation layer 21 into the deposition space 1. The outer bottom air group 60 is arranged on the bottom of the furnace shell 11 and extends through the bottom of the outer insulation layer 21 into the deposition space 1. The inner circumferential air group 70 is arranged on the furnace cover 12 and extends through the side wall of the inner insulation layer 22 into the deposition space 1. The inner bottom air group 80 is arranged on the bottom of the furnace cover 12 and extends through the inner insulation layer 22 into the deposition space 1.

[0027] like Figure 2 、 2a As shown, in this preferred embodiment, the inner insulation layer 22 is preferably provided to include an inner insulation barrel 23 and a top insulation ring 24. Specifically, the inner insulation barrel 23 is fixed at the center position of the bottom of the furnace cover 12, and the top insulation ring 24 is fixed at the four sides of the bottom of the furnace cover 12. When the furnace cover 12 covers the opening 11a of the furnace shell, the inner insulation barrel 23 protrudes toward the inner center position of the outer insulation layer 21, and a gap matching the barrel-shaped workpiece 3 is formed between the inner insulation barrel 23 and the outer insulation layer 21, which is the deposition space 1; the top insulation ring 24 just blocks the gap between the outer insulation layer 21 and the inner insulation barrel 23, and can cover the bottom of the furnace cover 12, which can prevent the metal furnace cover 12 from contaminating the process gas and facilitate the rapid replacement of the inner insulation layer 22 in different areas.

[0028] Preferably, a center hole 12a is provided at the center of the furnace cover 12, and raised portions 12b extending toward the furnace shell 11 are provided around the bottom of the furnace cover 12. The raised portions 12b precisely match the extension of the furnace shell opening 11a to form a reliable seal. The inner insulating barrel 13 is fixedly installed in the center hole 12a of the furnace cover, the inner insulation barrel 23 is sleeved on the outside of the inner insulation barrel 13, and the top insulation ring 24 is embedded between the inner insulation barrel 23 and the raised portion 12b of the furnace cover. Specifically, the inner insulation barrel 13 is embedded in the center hole 12a, with the opening of the inner insulation barrel facing the outside of the furnace cover 12, to facilitate the installation of the inner circumferential inflation group 70 and the inner bottom inflation group 80 in the inner insulation barrel 13.

[0029] In this preferred embodiment, an inner circumferential air filling group 70 is preferably provided, comprising an inner air guide ring 71, an inner air guide pipe 72, and an inner air nozzle 73. There are multiple inner air guide rings 71, each fixedly mounted at different vertical positions on the inner wall of the inner isolation barrel 13. An inner air guide pipe 72 is provided for each inner air guide ring 71, and each inner air guide pipe 72 passes through the top of the furnace cover 12 to connect the external air pipe with the corresponding inner air guide ring 71. Multiple inner air nozzles 73 are evenly distributed on each inner air guide ring 71, and these inner air nozzles 73 pass through the inner air guide ring 71, the inner isolation barrel 13, and the inner insulation barrel 23 to connect the deposition space 1 with the inner bottom air guide ring 81. Preferably, an inner air nozzle 73 can be provided, including a hollow tubular portion 74 and a head 75 arranged at one end of the tubular portion 74, a seal 76 is provided between the head 75 and the corresponding inner air guide ring 71, and the outer circumferential surface of the tubular portion 74 is provided with a threaded section 74a that cooperates with the inner isolation barrel 13. Specifically, a threaded hole 13a that cooperates with the threaded section 74a can be opened at the corresponding position of the inner isolation barrel 13. The tubular portion 74 of the inner air nozzle is provided with a plurality of connecting holes 74b evenly distributed around the circumference at the position corresponding to the inner air guide ring 71, so that the process gas in the inner air guide ring 71 can enter the hollow part of the tubular portion 74 of the inner air nozzle through the connecting holes 74b; specifically, a mounting hole 71a can be opened at the corresponding position of the inner air guide ring 71, and the inner air nozzle 73 can be inserted into the corresponding mounting hole 71a, and the head 75 of the inner air nozzle and the outer surface of the inner air guide ring 71 are sealed by a seal 76; then the inner air nozzle 73 is rotated so that the threaded section 74a of the inner air nozzle cooperates with the threaded hole 13a of the inner isolation barrel, and the insertion end 77 of the inner air nozzle opposite to the head passes through the inner insulation barrel 23 into the deposition space 1, thereby stably and reliably fixing the inner air nozzle 73 on the inner isolation barrel 13, and at the same time positioning the inner air guide ring 71 at the corresponding height position on the inner wall of the inner isolation barrel 13.

[0030] In this preferred embodiment, an inner bottom aeration group 80 is preferably provided, comprising a plurality of inner bottom air guide rings 81 concentrically arranged at the inner bottom of the inner isolation barrel 13, inner bottom air guide pipes 82 passing through the top of the furnace cover 12 to connect the external air pipe with the inner bottom air guide rings 81, and inner bottom air nozzles 83 evenly distributed on the inner bottom air guide rings 81. An inner bottom air guide pipe 82 is provided for each inner bottom air guide ring 81, and each inner bottom air guide pipe 82 passes through the top of the furnace cover 12 to connect the external air pipe with the corresponding inner bottom air guide ring 81; each inner bottom air guide ring 81 is evenly distributed with a plurality of inner bottom air nozzles 83, which pass through the inner bottom air guide ring 81, the inner isolation barrel 13, and the inner insulation barrel 23 to connect the deposition space 1 with the inner air guide ring 71. Preferably, an inner bottom air nozzle 83 can also be provided, which includes a hollow tubular portion and a head arranged at one end of the tubular portion. A seal is provided between the head and the corresponding inner bottom air guide ring 81. The outer circumferential surface of the tubular portion is provided with a threaded section that cooperates with the inner isolation barrel 13. Specifically, a threaded hole that cooperates with the threaded section can be opened at the corresponding position of the inner isolation barrel 13. The tubular portion of the inner bottom air nozzle 83 is provided with a plurality of connecting holes evenly distributed around the circumference at the position corresponding to the inner bottom air guide ring 81, so that the process gas in the inner bottom air guide ring 81 can enter the hollow part of the tubular portion of the inner bottom air nozzle 83 through the connecting holes; specifically, a mounting hole can be opened at the corresponding position of the inner bottom air guide ring 81, and the inner bottom air nozzle 83 can be inserted into the corresponding mounting hole, and the head of the inner bottom air nozzle 83 and the outer surface of the inner bottom air guide ring 81 are sealed by a seal; then the inner bottom air nozzle 83 is rotated so that the threaded section of the inner bottom air nozzle 83 cooperates with the threaded hole of the inner isolation barrel 13, and the insertion end of the inner bottom air nozzle 83 opposite to the head passes through the inner insulation barrel 23 and enters the deposition space 1, thereby stably and reliably fixing the inner bottom air nozzle 83 on the inner isolation barrel 13, and at the same time positioning the inner bottom air guide ring 81 at the corresponding position on the inner bottom wall of the inner isolation barrel 13.

[0031] In this preferred embodiment, the exhaust system is preferably provided including an exhaust channel 41 provided between the top insulation ring 24 and the inner insulation barrel 23 and an exhaust pipe 42 provided on the furnace cover 12. An exhaust port 43 corresponding to the exhaust pipe 42 is provided in the exhaust channel 41, and a plurality of exhaust holes 44 are evenly distributed on the circumference of the top insulation ring 24. The exhaust holes 44 connect the deposition space 1 to the exhaust channel 41. Specifically, an annular groove can be opened on the top insulation ring 24, and the notch of the annular groove is blocked by the side wall of the inner insulation barrel 23, forming a closed annular channel between the top insulation ring 24 and the inner insulation barrel 23, which is the exhaust channel 41. The exhaust pipe 42 can be set on the side or top surface of the furnace cover 12, and the exhaust port 43 can be opened at the corresponding position on the side or top surface of the top insulation ring 24, so that the exhaust channel 41 is connected to the exhaust pipe 42.

[0032] like Figure 3 、 3aAs shown, in this preferred embodiment, an outer isolation tube 14 is preferably provided between the outer insulation layer 21 and the side wall of the inner insulation barrel 23, and a closed heating chamber 15 is provided between the outer isolation tube 14 and the outer insulation layer 21. The heater 2 is provided in the heating chamber 15 to prevent the heater 2 from contaminating the process gas, thereby further ensuring the deposition quality of the workpiece.

[0033] In this preferred embodiment, an outer circumferential gas filling assembly 50 is preferably provided, comprising an outer gas duct 51 fixed to the circumferential side surface of the furnace shell 11, and an outer gas nozzle 52 extending through the side wall of the outer insulation layer 21 and the side wall of the outer isolation barrel 14. One end of the outer gas nozzle 52 is inserted into the outer gas duct 51, and the other end is fixed to the side wall of the outer isolation barrel 14 and extends into the deposition space 1. The outer gas nozzle 52 can be fixed to the side wall of the outer isolation barrel 14 by a fastener or fastening structure, such as a nut or a threaded connection structure.

[0034] In this preferred embodiment, an outer bottom inflation group 60 is preferably provided, including an outer bottom air nozzle 61 passing through the outer shell and the bottom of the outer insulation layer. The outer bottom air nozzle 61 is fixed to the bottom of the furnace shell 11 by a fastener or a fastening structure. One end of the outer bottom air nozzle 61 extends into the deposition space 1, and the other end is connected to the external air pipe.

[0035] In this preferred embodiment, a process gas station is further included to provide process gas. All the gas filling groups are connected to the process gas station through air pipes, and the gas volume of the process gas is controlled by a near-term controller.

[0036] Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making any creative work, any modifications, equivalent substitutions, improvements, etc. made should be included in the scope of protection of the present invention.

Claims

1. A chemical vapor deposition device suitable for barrel-shaped workpieces, comprising a furnace body, a thermal insulation layer, a deposition space and a heater arranged in the thermal insulation layer, an air injection system, and an exhaust system, characterized in that: The furnace body comprises a furnace shell with an open top and a furnace cover covering the open top of the furnace shell; The thermal insulation layer includes an outer thermal insulation layer arranged closely against the inner side wall and inner bottom of the furnace shell, and an inner thermal insulation layer arranged at the bottom of the furnace cover and protruding toward the inner center of the outer thermal insulation layer. The outer thermal insulation layer and the inner thermal insulation layer are combined to form the deposition space. The injection system includes an outer circumferential inflation group that is evenly distributed and fixed on the circumferential side of the furnace shell, passes through the side wall of the outer insulation layer and extends into the deposition space, an outer bottom inflation group that is arranged on the bottom of the furnace shell, passes through the bottom of the outer insulation layer and extends into the deposition space, an inner circumferential inflation group that is arranged on the furnace cover, passes through the side wall of the inner insulation layer and extends into the deposition space, an inner bottom inflation group that is arranged on the furnace cover, passes through the bottom of the inner insulation layer and extends into the deposition space, and an air intake controller that is respectively connected to the outer circumferential inflation group, outer bottom inflation group, inner circumferential inflation group and inner bottom inflation group through air pipes and controls the air intake flow rate of each inflation group.

2. The chemical vapor deposition equipment suitable for barrel-shaped workpieces according to claim 1, characterized in that: The inner insulation layer includes an inner insulation barrel fixed at the center position of the bottom of the furnace cover and a top insulation ring fixed around the bottom of the furnace cover. When the furnace cover covers the opening of the furnace shell, the inner insulation barrel protrudes toward the center position inside the outer insulation layer, and the top insulation ring seals the gap between the outer insulation layer and the inner insulation barrel.

3. The chemical vapor deposition equipment suitable for barrel-shaped workpieces according to claim 2, characterized in that: The furnace cover is provided with a center hole in the center and raised portions extending toward the furnace shell are provided around the bottom. An inner insulating barrel is fixed at the center hole of the furnace cover, the inner insulation barrel is sleeved on the outside of the inner insulation barrel, and the top insulation ring is embedded between the inner insulation barrel and the raised portion of the furnace cover.

4. The chemical vapor deposition equipment suitable for barrel-shaped workpieces according to claim 3, characterized in that: The inner circumferential inflation group includes a plurality of inner air guide rings fixedly arranged at different vertical positions on the inner wall of the inner isolation barrel, an inner air guide pipe passing through the top of the furnace cover to connect the external air pipe with the inner air guide ring, and inner air nozzles evenly distributed on the inner air guide ring. The inner air nozzles pass through the inner air guide ring, the inner isolation barrel and the inner insulation barrel to connect the deposition space with the inner air guide ring.

5. The chemical vapor deposition equipment suitable for barrel-shaped workpieces according to claim 4, characterized in that: The inner air nozzle includes a hollow tubular portion and a head arranged at one end of the tubular portion. A seal is provided between the head and the inner air guide ring. The outer circumferential surface of the tubular portion is provided with a threaded section that cooperates with the inner isolation barrel. The tubular portion is provided with connecting holes evenly distributed around the circumference corresponding to the inner air guide ring.

6. The chemical vapor deposition equipment suitable for barrel-shaped workpieces according to claim 3, characterized in that: The inner bottom inflation group includes a plurality of concentrically arranged inner bottom air guide rings fixedly arranged on the inner bottom of the inner isolation barrel, an inner bottom air guide pipe passing through the top of the furnace cover to connect the external air pipe with the inner bottom air guide ring, and inner bottom air nozzles evenly distributed on the inner bottom air guide ring. The inner bottom air nozzles pass through the inner bottom air guide ring, the inner isolation barrel and the inner insulation barrel to connect the deposition space with the inner bottom air guide ring.

7. The chemical vapor deposition equipment suitable for barrel-shaped workpieces according to claim 6, characterized in that: The inner bottom air nozzle includes a hollow tubular portion and a head arranged at one end of the tubular portion. A seal is provided between the head and the inner bottom air guide ring. The outer circumferential surface of the tubular portion is provided with a threaded section that cooperates with the inner isolation barrel. The tubular portion is provided with connecting holes evenly distributed around the circumference corresponding to the inner bottom air guide ring.

8. The chemical vapor deposition equipment suitable for barrel-shaped workpieces according to claim 3, characterized in that: The exhaust system includes an exhaust channel arranged between the top insulation ring and the inner insulation barrel and an exhaust pipe arranged on the furnace cover. An exhaust port corresponding to the exhaust pipe is provided in the exhaust channel, and a plurality of exhaust holes are evenly distributed on the circumference of the top insulation ring to connect the deposition space to the exhaust channel.

9. The chemical vapor deposition equipment suitable for barrel-shaped workpieces according to claim 2, characterized in that: An outer insulating tube is provided between the outer insulating layer and the side wall of the inner insulating barrel, a sealed heating chamber is provided between the outer insulating tube and the outer insulating layer, and the heater is arranged in the heating chamber.

10. The chemical vapor deposition equipment suitable for barrel-shaped workpieces according to claim 9, characterized in that: The outer circumferential inflation group includes an outer air duct fixed on the circumferential side of the furnace shell, and an outer air nozzle passing through the side wall of the outer isolation tube and the side wall of the outer insulation layer. One end of the outer air nozzle is inserted into the outer air duct and the other end is fixed on the side wall of the outer isolation tube and extends into the deposition space.

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