Vertical furnace

Abstract

The utility model provides a vertical furnace which comprises an upper furnace cover, a lower furnace door, an outer furnace tube and an inner furnace tube which define a containing cavity, the upper furnace cover and the lower furnace door are arranged at the upper end and the lower end of the outer furnace tube respectively, and the inner furnace tube is arranged on the inner side of the outer furnace tube. One end, close to the lower furnace door, of the inner furnace tube is a closed end and keeps a distance from the lower furnace door; a rotatable carrier boat bearing device for bearing a carrier boat of the vertical furnace is arranged in the accommodating cavity, and a driving device for driving the carrier boat bearing device to rotate is arranged on one side, far away from the accommodating cavity, of the lower furnace door; according to the vertical furnace provided by the utility model, the rotatable carrier boat bearing device used for bearing the carrier boat is arranged, and the driving device is used for driving the carrier boat bearing device to rotate in the accommodating cavity, so that the carrier boat borne by the carrier boat bearing device is driven to rotate together, and the heating uniformity of silicon wafers on the carrier boat is further improved.

Description

Technical Field

[0001] The utility model belongs to the technical field of equipment for manufacturing semiconductors, and more specifically, relates to a vertical furnace. Background Art

[0002] At present, the diffusion, oxidation, annealing, doping, PECVD (low pressure chemical vapor deposition), LPCVD (plasma enhanced chemical vapor deposition) and other processes in the photovoltaic industry are produced in two types: vertical furnaces and horizontal furnaces. Both types of structures require the silicon wafers to be placed in a specific carrier and transferred into the reaction chamber for processing. By introducing specific reaction gases, the silicon wafers can be subjected to specific coating, diffusion, oxidation and thin film deposition processes. In the existing two-layer furnace tube design, the base and the top wall are used to seal the two ends of the double-layer furnace tube to form a straight-through cavity, the silicon wafer to be processed is placed in the straight-through cavity, and the heating layer on the double-layer furnace tube is used to heat the straight-through cavity.

[0003] However, the main problem with the furnace tube structure is that the structure of the carrier boat is fixed and the position and angle cannot be adjusted. This placement will cause the gas field and thermal field to be locally uneven when the reaction gas is introduced or the temperature difference is increased, resulting in poor uniformity when the decomposition and silicon wafer react under high temperature, affecting the overall process yield and causing uneven quality of the cells produced in the same batch. Utility Model Content

[0004] The utility model aims to provide a vertical furnace to solve the problem in the prior art that silicon wafers on the carrier boat are heated unevenly due to the fixed position of the carrier boat.

[0005] To achieve the above-mentioned purpose, the technical solution adopted by the utility model is: to provide a vertical furnace, comprising an upper furnace cover, a lower furnace door, an outer furnace tube and an inner furnace tube which enclose a containing cavity, wherein the upper furnace cover and the lower furnace door are respectively arranged at the upper and lower ends of the outer furnace tube, the inner furnace tube is arranged on the inner side of the outer furnace tube, and one end of the inner furnace tube close to the lower furnace door is a closed end and a distance is maintained between the closed end and the lower furnace door;

[0006] A rotatable boat carrier device for carrying the boat is provided in the accommodating chamber, and a driving device for driving the boat carrier device to rotate is provided on a side of the lower furnace door away from the accommodating chamber.

[0007] Furthermore, the carrier boat carrying device comprises:

[0008] a first rotating base, located between the closed end of the inner furnace tube and the lower furnace door;

[0009] A rotating shaft connected to the driving device and arranged on one side of the first rotating base;

[0010] The first bearing member is used for bearing the carrier boat, is arranged on the other side of the first rotating base, and is sleeved on the outer side of the inner furnace tube.

[0011] Furthermore, the driving device comprises:

[0012] A motor is arranged on a side of the lower furnace door away from the accommodating cavity;

[0013] The magnetic fluid sealing component comprises a transmission shaft, one end of which is connected to the motor through a belt, and the other end of which is connected to the rotating shaft.

[0014] Furthermore, the first bearing member includes a plurality of hanging plates spaced apart on the first rotating base, and each hanging plate is provided with a hook hole for being hung by a hook on the carrier boat.

[0015] Furthermore, the carrier boat bearing device also includes: a first heat insulating member, which is arranged on the first rotating base and has a central area thereof provided with a plurality of limiting holes for the plurality of hanging plates to pass through.

[0016] Furthermore, the carrier boat bearing device also includes: a second heat insulating member, which is arranged on the first rotating base and has a plurality of notches at its edge area for the plurality of hanging plates to pass through.

[0017] Furthermore, the carrier boat carrying device comprises:

[0018] A second rotating base is placed in the accommodating cavity and sleeved on the outer side of the inner furnace tube, and the second rotating base is provided with a plurality of bearing positions for the carrier boat to pass through;

[0019] A rotating connecting member, located between the closed end of the inner furnace tube and the lower furnace door, connecting the second rotating base and the driving device;

[0020] A plurality of pairs of second bearing members are used to bear the carrier boat, each pair of bearing members is located at two sides of a bearing position and is foldably arranged on the second rotating base.

[0021] Furthermore, the driving device comprises:

[0022] A motor is arranged on a side of the lower furnace door away from the accommodating cavity;

[0023] The magnetic fluid sealing component comprises a transmission shaft, one end of which is connected to the motor through a belt, and the other end of which is connected to the rotating connecting piece.

[0024] Further, each second bearing member in each pair of second bearing members includes a bearing fixed portion and a bearing movable portion, the bearing fixed portion is fixedly disposed on the second rotating base, and the bearing movable portion is rotatably disposed on the bearing fixed portion.

[0025] Furthermore, the upper end surface of the upper furnace cover away from the accommodating cavity protrudes upward to form a spherical protrusion.

[0026] Furthermore, a central hole for the inner furnace tube to pass through is provided in the middle of the upper furnace cover, a cavity is provided inside the upper furnace cover around the central hole, and a plurality of cavity ribs connected between the upper and lower inner walls of the cavity are provided in the cavity.

[0027] Furthermore, the upper furnace cover also includes a lower plate, an outer plate and an inner plate that cooperate with the upper end surface to enclose the cavity, and the lower plate, the outer plate and the inner plate are all hollow plates to form a water flow channel or a wind flow channel.

[0028] Furthermore, a connector for hoisting is provided at one end of the central hole of the upper furnace cover through which the inner furnace tube passes.

[0029] Furthermore, the lower furnace door can be arranged to cover the lower end of the outer furnace tube.

[0030] Furthermore, a small furnace door is provided on the lower furnace door, and the small furnace door includes a small furnace door opening that passes through the lower furnace door, and a small furnace door cover corresponding to the small furnace door opening, and the small furnace door cover is connected to a driving structure, and the driving structure is used to drive the small furnace door cover to open or close relative to the small furnace door opening.

[0031] Furthermore, there are a plurality of carrier boats, which are arranged in a circular shape and spaced apart in the accommodating cavity of the vertical furnace.

[0032] Furthermore, an inner heating element is provided on the inner side of the inner furnace tube, and an outer heating element is provided on the outer side of the outer furnace tube. Both the inner heating element and the outer heating element are composed of a plurality of independent heating sections.

[0033] The beneficial effect of the vertical furnace provided by the utility model is that compared with the prior art, the utility model arranges a rotatable carrier boat carrying device for carrying a carrier boat in the accommodating chamber of the vertical furnace, and drives the carrier boat carrying device to rotate through a driving device, thereby driving the carrier boat carried by the carrier boat carrying device to rotate together, thereby improving the heating uniformity of the silicon wafers on the carrier boat. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. 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 creative labor.

[0035] Figure 1 A schematic diagram of the structure of a vertical furnace provided in Embodiment 1 of the utility model;

[0036] Figure 2 for Figure 1 Sectional view at AA;

[0037] Figure 3 A schematic diagram of the structure of the carrier boat carrying device provided in the first embodiment of the utility model Figure 1 ;

[0038] Figure 4 A schematic diagram of the structure of the carrier boat carrying device provided in the first embodiment of the utility model Figure 2 ;

[0039] Figure 5 A top view of the heating element and the heat dissipation element provided in the first embodiment of the present utility model in conjunction with the inner and outer furnace tubes;

[0040] Figure 6 A schematic diagram of the structure of a lower furnace door provided with a small furnace door in the first embodiment of the utility model;

[0041] Figure 7 A schematic diagram of the partial structure of the lower furnace door with the small furnace door and furnace cover removed provided in the first embodiment of the utility model;

[0042] Figure 8 for Figure 7 Side view of

[0043] Fig. 9 A schematic diagram of the structure of the small furnace door and furnace cover cooperation driving structure provided in the first embodiment of the utility model;

[0044] Fig.10 for Fig. 9 Side view of

[0045] Fig.11 A schematic diagram of the structure of a vertical furnace provided in Embodiment 2 of the present utility model;

[0046] Fig.12 for Fig.11 Sectional view at the middle BB;

[0047] Fig.13 A schematic diagram of the structure of a carrier boat carrying device provided in the second embodiment of the utility model;

[0048] Among them, the main marks of the drawings in the figure are:

[0049] 13. outer furnace tube; 14. inner furnace tube; 15. carrier boat carrying device; 16. driving device; 17. carrier boat; 161. magnetic fluid sealing assembly; 162. belt; 163. motor;

[0050] 2. Upper furnace cover; 21. Reinforcement ribs; 22. Lower layer; 23. Inner layer; 24. Outer layer; 25. Connector;

[0051] 3. Lower furnace door; 31. Small furnace door and furnace opening; 311. First protrusion; 312. Annular cavity;

[0052] 32. small furnace door and furnace cover; 321. second protrusion; 322. mounting plate; 323. first guide column; 324. weight reduction hole;

[0053] 33. driving structure; 331. rotating driving device; 332. coupling; 333. rotating shaft; 334. rotating plate; 335. push-pull driving device; 336. mounting area; 337. second guide column; 338. first electrical interface; 339. second electrical interface; 340. connecting plate; 341. first partition; 342. second partition; 343. third partition; 344. first accommodating space; 345. second accommodating space;

[0054] 41. fixed ring; 42. first rotating base; 47. rotating shaft; 43. first bearing member; 491. first heat insulating member; 492. second heat insulating member;

[0055] 71. External heating element; 72. Internal heating element; 73. First heat dissipation element; 74. Second heat dissipation element; 75. Water cooling interface;

[0056] 81. Second rotating base; 82. Second bearing member; 83. Rotating connecting member; 821. Bearing fixed part; 822. Bearing movable part. DETAILED DESCRIPTION

[0057] In order to make the technical problems, technical solutions and beneficial effects to be solved by the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0058] Embodiment 1:

[0059] For ease of understanding, the following directions are explained first: the axial direction of the vertical furnace is the up-and-down direction, and the radial direction of the vertical furnace is the in-and-out direction.

[0060] Please also read Figure 1 , Figure 2 The vertical furnace provided in this embodiment includes an upper furnace cover 2, a lower furnace door 3, an outer furnace tube 13, an inner furnace tube 14, a carrier boat bearing device 15 and a driving device 16.

[0061] In this embodiment, the upper furnace cover 2 and the lower furnace door 3 are arranged opposite to each other, the outer furnace tube 13 is arranged between the upper furnace cover 2 and the lower furnace door 3, and the inner furnace tube 14 is arranged on the inner side of the outer furnace tube 13. At the same time, the inner furnace tube 14 is arranged coaxially with the outer furnace tube 13. The lower end of the outer furnace tube 13 is an open end, and the lower furnace door 3 is arranged at the open end of the outer furnace tube 13. The lower end of the inner furnace tube 14 is a closed end, and a distance is maintained between the lower end of the inner furnace tube 14 and the lower furnace door 3. At this time, the inner furnace tube 14, the outer furnace tube 13, the upper furnace cover 2 and the lower furnace door 3 together constitute a receiving cavity with a concave cross-section. The carrier boat carrying device 15 is rotatably disposed in the accommodating cavity, and the carrier boat carrying device 15 is used to carry the carrier boat 17. The driving device 16 is disposed on the side of the lower furnace door 3 away from the accommodating cavity, and the driving device 16 is connected to the carrier boat carrying device 15. The driving device 16 is used to drive the carrier boat carrying device 15 to rotate in the accommodating cavity, thereby driving the carrier boat 17 disposed on the carrier boat carrying device 15 to rotate synchronously, thereby making the silicon wafers on the carrier boat 17 heated evenly.

[0062] In this embodiment, please refer to Figure 2 , Figure 3 , Figure 4 The carrier boat carrying device 15 includes a first rotating base 42, a rotating shaft 47 and a first bearing member 43. The first rotating base 42 is located between the closed end of the inner furnace tube 14 and the lower furnace door 3, the rotating shaft 47 is arranged on one side of the first rotating base 42, the rotating shaft 47 is connected to the driving device 16, the first bearing member 43 is arranged on the other side of the first rotating base 42, and is sleeved on the outer side of the inner furnace tube 14, and the first bearing member 43 is used to carry the carrier boat 17.

[0063] In a specific example of this embodiment, Figure 2 , Figure 3As shown, the carrier boat carrying device 15 includes a first rotating base 42, a first heat insulating member 491, a fixing ring 41, a first bearing member 43 and a rotating shaft 47. The first rotating base 42 is spaced apart and placed parallel to the fixing ring 41, and the first bearing member 43 includes a plurality of hanging plates spaced apart and arranged in a ring shape between the first rotating base 42 and the fixing ring 41, and the plurality of hanging plates are fixed at the edge of the first rotating base 42. At least one hook hole for hanging the carrier boat 17 is spaced apart along the height direction of the hanging plates, and the carrier boat 17 can be a vertical quartz boat. The first heat insulating member 491 is arranged on the upper side of the first rotating base 42, and the rotating shaft 47 is arranged on the lower side of the first rotating base 42. The first heat insulating member 491 has an open end on one side facing the first rotating base 42. The first heat insulating member 491 and the first rotating base 42 form a receiving chamber, and the receiving chamber is filled with heat insulating materials. The first heat insulating member 491 and the heat insulating materials can prevent the heat in the vertical furnace from being transferred to the lower furnace door 3 through the first rotating base 42. On the one hand, the lower furnace door 3 and the driving device 16 and other parts can be protected, and on the other hand, the energy loss in the vertical furnace can be reduced. The edge area of ​​the first heat insulating member 491 is also provided with a plurality of gaps distributed at intervals, and the setting of the gaps can provide favorable conditions for installing the hanging plate.

[0064] In another specific example of this embodiment, Figure 4 As shown, the carrier boat bearing device 15 includes a first rotating base 42, a second heat insulating member 492, a fixed ring 41, a first bearing member 43 and a rotating shaft (marked in the figure). The first rotating base 42 is spaced apart and placed parallel to the fixed ring 41, and the first bearing member 43 includes four hanging plates spaced apart and arranged in a ring shape between the first rotating base 42 and the fixed ring 41, and the first bearing member 43 is fixed to the central area of ​​the first rotating base 42. At least one hook hole for hanging the carrier boat 17 is spaced apart along the height direction of the hanging plates, and the carrier boat 17 can be a vertical quartz boat. The second heat insulating member 492 is arranged on the upper side of the first rotating base 42, and the rotating shaft is arranged on the lower side of the first rotating base 42. The side of the second heat insulating member 492 facing the first rotating base 42 is an open end, and the second heat insulating member 492 and the first rotating base 42 form a receiving chamber, and the receiving chamber is filled with heat insulating material. The second heat insulating member 492 and the heat insulating material can prevent the heat in the vertical furnace from being transferred to the lower furnace door 3 through the first rotating base 42, which can protect the lower furnace door and the drive device and other parts, and reduce the energy loss in the vertical furnace. The central area of ​​the second heat insulating member 492 is also provided with a plurality of limiting holes, which can be used for the hanging plate to pass through, and the setting of the limiting holes provides favorable conditions for installing the hanging plate.

[0065] In this embodiment, if Figure 2 , Figure 3As shown, the driving device 16 is arranged on the side of the lower furnace door 3 away from the accommodating chamber. The driving device 16 includes a magnetic fluid sealing component 161, a belt 162 and a motor 163. The magnetic fluid sealing component 161 includes a transmission shaft, one end of which is connected to the motor 163 through the belt 162, and the other end is connected to the rotating shaft 47 in the carrier boat bearing device 15. The motor 163 drives the carrier boat bearing device 15 to rotate, thereby driving the carrier boat 17 suspended on the carrier boat bearing device 15 to rotate together. It should be noted that the magnetic fluid sealing component 161 includes a fixed seat and a transmission shaft arranged on the inner side of the fixed seat, and two magnetic poles are arranged on the outer side of the transmission shaft along the axial interval, and a permanent magnet is arranged between the two magnetic poles. There is a gap between the two magnetic poles and the transmission shaft, and the gap is filled with magnetic fluid. Magnetic fluid is a colloidal liquid combined with solid and liquid, which is made of magnetic nanoparticles, which are evenly dispersed into a liquid (carrier liquid) with a very low saturated vapor pressure after special treatment, and is mixed with the liquid by a dispersant and does not precipitate or solidify. It has both the fluidity of liquid and magnetism. Magnetic fluid vacuum dynamic seal is realized based on this characteristic. Magnetic fluid seal assembly 161 utilizes the characteristics of magnetic fluid, and uses magnets to fix the magnetic fluid around the shaft to form a liquid "O-ring". Through the connection between the magnetic fluid seal assembly 161 and the rotatable carrier boat bearing device 15, under the premise of ensuring that power can be transmitted, the furnace will not lose pressure and the process gas will not leak out.

[0066] In this embodiment, if Figure 2 As shown, the upper end of the inner furnace tube 14 is higher than the upper end of the outer furnace tube 13, and the upper end of the inner furnace tube 14 is an open end. The upper end of the inner furnace tube 14 is provided with a connector 25 for hoisting. The arrangement of the connector 25 enables the inner furnace tube 14 to be connected to an external hoisting connector. The hoisting connector can provide strength to the inner furnace tube 14 so as to ensure that the inner furnace tube 14 is suspended on the inner side of the outer furnace tube 13. The hoisting connector is not limited to the piles arranged on the ceiling. The lower end of the inner furnace tube 14 is a closed end and is hemispherical. By arranging the lower end of the outer furnace tube 13 to be hemispherical, it can withstand greater pressure and is more suitable for the demand of vacuuming inside the vertical furnace. The inner furnace tube 14 can be made of a quartz tube. The outer wall of the inner furnace tube 14 and the inner wall of the outer furnace tube 13 form a reaction chamber, which is a part of the aforementioned accommodating chamber. When the carrier boat 17 enters the interior of the vertical furnace, the carrier boat 17 is mainly placed in the reaction chamber.

[0067] In this embodiment, if Figure 2As shown, the upper furnace cover 2 is arranged at the upper end of the outer furnace tube 13, and the upper furnace cover 2 is sealed and connected to the outer furnace tube 13. The middle part of the upper furnace cover 2 is provided with a central hole for the inner furnace tube 14 to pass through, and the central hole of the upper furnace cover 2 and the upper end (open end) of the inner furnace tube 14 form concentric circles at a top view angle. The upper end surface of the upper furnace cover 2 protrudes upward as a spherical protrusion structure, and such a design enables the upper furnace cover 2 to withstand greater pressure and prevent it from being sucked out when the vertical furnace is vacuumed. The upper furnace cover 2 is provided with a cavity around the central hole. The upper furnace cover 2 also includes a lower plate 22, an inner plate 23, and an outer plate 24 that are matched with the upper end surface to form the aforementioned cavity. The aforementioned cavity is provided with a plurality of cavity ribs 21 connected between the upper and lower inner walls of the cavity, and the plurality of reinforcing ribs 21 are all plate-shaped and have a plurality of through holes on the plate surface, and the plurality of reinforcing ribs 21 are arranged in an annular interval in the annular cavity. The reinforcing ribs 21 can enhance the pressure resistance of the outer furnace cover. A water cooling component or an air cooling component can also be set in the upper furnace cover 2. The lower layer 22, the inner layer 23, and the outer layer 24 are all hollow layers to form a water flow channel or an air flow channel. During the operation of the vertical furnace, water or wind can be used to continuously take away excess heat, thereby facilitating temperature control in the vertical furnace.

[0068] In this embodiment, if Figure 2 , Figure 5 As shown, heating elements are provided on both the inner furnace tube 14 and the outer furnace tube 13 to achieve heating of the accommodating cavity in the vertical furnace. The heating element on the inner furnace tube 14 is arranged on the outer side of the inner furnace tube 14, and the heating element on the inner furnace tube 14 is referred to as the inner heating element 72 hereinafter. The heating element on the outer furnace tube 13 is arranged on the inner side of the outer furnace tube 13, and the heating element on the outer furnace tube 13 is referred to as the outer heating element 71 hereinafter. Both the inner heating element 72 and the outer heating element 71 can be selected from heating wires, infrared lamps, electromagnetic induction heating, etc. By independently controlling the heating by setting the outer heating element 71 and the inner heating element 72, a high temperature environment required for the silicon wafer reaction is formed.

[0069] In a specific example of this embodiment, the inner heating element 72 covers the entire inner side of the inner furnace tube 14, and the inner heating element 72 adopts a heating wire, and the inner heating element 72 is formed by the heating wire being evenly wound along the axial direction of the inner furnace tube 14. Similarly, the outer heating element 71 covers the entire inner side of the inner furnace tube 14, and the outer heating element 71 adopts a heating wire, and the outer heating element 71 is formed by the heating wire being evenly wound along the axial direction of the outer furnace tube 13.

[0070] In another specific example of the present embodiment, the inner heating element 72 is composed of a plurality of first independent heating segments, each of which uses a heating wire, and each first independent heating is formed by winding the heating wire along the axial direction of the inner furnace tube 14, and the distribution density of the heating wires between different first independent heating segments can be the same or different. Similarly, the outer heating element 71 is composed of a plurality of second independent heating segments, and each second independent heating is formed by winding the heating wire along the axial direction of the outer furnace tube 13, and the distribution density of the heating wires between different first independent heating segments can be the same or different. In this example, both the inner heating element 72 and the outer heating element 71 are composed of a plurality of independent heating segments, that is, the inner heating element 72 is composed of a plurality of first independent heating segment groups, and the outer heating element 71 is composed of a plurality of second independent heating segments, so that the inner and outer heating elements can be zoned and / or layered and independently controlled for heating.

[0071] In this embodiment, if Figure 2 , Figure 5 As shown, heat dissipation elements can be provided on both the inner furnace tube 14 and the outer furnace tube 13 to achieve rapid and stable adjustment of the temperature of the inner and outer furnace tubes 13. Specifically, a first heat dissipation element 73 is provided on the inner side of the inner furnace tube 14. At the same time, the first heat dissipation element 73 and the inner heating element 72 can be provided to be independently and separately provided, or the first heat dissipation element 73 and the inner heating element 72 can be provided to ...

[0072] In this embodiment, if Figure 2 As shown, a water-cooling joint 75 is provided at the connection position between the outer furnace tube 13 and the lower furnace door 3, for supplying water to the heat dissipation element arranged therein. Water flow channels or air flow channels may also be provided on the inner furnace tube 14 and the outer furnace tube 13, and even water flow channels or air flow channels may be provided inside the heating elements on the inner furnace tube 14 and the outer furnace tube 13, so as to better control the temperature in the vertical furnace.

[0073] In this embodiment, the lower furnace door 3 can be an integrated furnace door or a split furnace door.

[0074] In a specific example of this embodiment, the lower furnace door 3 is an integrated furnace door, that is, the lower furnace door 3 is a whole. By opening the integrated furnace door to expose the open end of the outer furnace tube 13, all the carrier boats 17 in the accommodating cavity can be taken out. In addition, the side of the lower furnace door 3 close to the accommodating cavity of the three-dimensional furnace is a spherical protrusion structure. This design enables the lower furnace door 3 to withstand greater pressure and prevent it from being sucked out when the vertical furnace is vacuumed.

[0075] In another specific example of this embodiment, Figure 2 , Figures 6 to 10 As shown, a small furnace door is provided on the lower furnace door 3, and the small furnace door includes a small furnace door furnace mouth 31 and a small furnace door furnace cover 32. The small furnace door furnace cover 32 is connected to a driving structure 33, and the driving structure 33 is used to drive the small furnace door furnace cover 32 to open or close relative to the small furnace door furnace mouth 31. When there are multiple small furnace doors, the multiple small furnace doors can be arranged in a circular shape or randomly arranged without a regular pattern, as long as the small furnace doors do not interfere with other components on the vertical furnace.

[0076] Compared with the previous example, the lower furnace door 3 of this example adopts an integrated furnace door solution, which easily causes the heat in the vertical furnace to be dissipated into the atmosphere. When processing the second batch of silicon wafers, it is necessary to reheat from room temperature, which leads to increased energy consumption and costs. The lower furnace door 3 adopts a solution with multiple small furnace doors, which minimizes heat loss while ensuring that the carrier boat 17 can pass through the small furnace doors normally.

[0077] like Figure 7 As shown, in order to make the small furnace door cover 32 fit closely with the corresponding small furnace door opening 31, improve the sealing performance, and reduce the heat loss in the furnace body, the lower furnace door 3 is provided with a first protrusion 311 on the side facing the small furnace door cover 32, and the first protrusion 311 surrounds the small furnace door opening 31 to form an annular cavity 312, and the small furnace door opening 31 is completely located in the annular cavity 312. At the same time, the shape of the small furnace door opening 31 is adapted to the shape of the side of the carrier boat 17, so that the small furnace door opening 31 can be normally passed through the carrier boat 17.

[0078] like Figure 6 , Figure 8 As shown, the lower furnace door 3 is provided with a spherical protrusion structure, and such a design enables the lower furnace door 3 to withstand greater pressure and prevent it from being sucked out when the vertical furnace is vacuumed. It should be noted that, since the lower furnace door 3 is provided with a spherical protrusion structure, the contact area between the first protrusion 311 and the lower furnace door 3 is uneven, but the position where the first protrusion 311 cooperates with the small furnace door cover 32 is horizontal.

[0079] like Figure 7 , Fig. 9 , Fig.10As shown, a small furnace door cover 32 matching with the small furnace door opening 31 is provided with a second convex block 321 on the side facing the small furnace door opening 31, and the second convex block 321 can be matched and inserted into the annular cavity 312. Of course, in order to further improve the sealing between the small furnace door cover 32 and the corresponding small furnace door opening 31, a high temperature resistant sealing strip can be provided around the second convex block 321.

[0080] The first protrusion 311 and the second protrusion 321 are both in annular shape, and such a design enables the small furnace door cover 32 to quickly cover the small furnace door furnace opening 31, and it is sufficient for the center of the first protrusion 311 to be aligned with the center of the second protrusion 321. If the first protrusion 311 and the second protrusion 321 are set in other shapes, it is required that the outer side of the first protrusion 311 and the inner side of the second protrusion 321 are strictly aligned.

[0081] like Fig. 9 , Fig.10 As shown, the driving structure 33 includes a rotation driving device 331, a coupling 332, a rotating shaft 333, a rotating plate 334, a push-pull driving device 335 and a connecting plate 340. The rotation driving device 331 is preferably a rotation motor, and the push-pull driving device 335 is preferably a push-pull motor. The rotation driving device 331 is equipped with a first electrical interface 338, and the push-pull driving device 335 is equipped with a second electrical interface 339. Both the first electrical interface 338 and the second electrical interface 339 are used to electrically connect to a control unit that controls the furnace door structure.

[0082] like Figure 6 , Fig. 9 , Fig.10 As shown, a rotation drive device 331 is provided on one side of the lower furnace door 3 corresponding to each small furnace door furnace opening 31, and the rotating end of the rotation drive device 331 is connected to the rotating shaft 333 through a coupling 332, and the end of the rotating shaft 333 is connected to a rotatable rotating plate 334, and the rotating plate 334 is located in front of the small furnace door furnace opening 31; the coupling 332 can firmly connect the rotating end of the rotation drive device 331 and the rotating shaft 333, so that the rotating end of the rotation drive device 331 and the rotating shaft 333 rotate together and transmit torque and motion. , to ensure that in the process of transmitting motion and power, the relative position between the rotating end of the rotating drive device 331 and the rotating shaft 333 remains unchanged to achieve reliable transmission; and the coupling 332 can also compensate for the offset between the rotating end of the rotating drive device 331 and the rotating shaft 333, to ensure the continuity and stability of the transmission; and the coupling 332 can also mitigate impact and absorb vibration, reduce the wear and failure risks of the rotating end of the rotating drive device 331 and the rotating shaft 333, and improve the stability and reliability of the driving structure 33.

[0083] The middle part of the rotating plate 334 is bolted with a push-pull driving device 335 , and the push-pull end of the push-pull driving device 335 passes through the rotating plate 334 and is connected to the small furnace door and furnace cover 32 .

[0084] The driving structure 33 also includes a first partition plate 341 and a second partition plate 342 spaced apart at one end of the connecting plate 340, and a third partition plate 343 arranged at the other end of the connecting plate 340; a first accommodating space 344 is formed between the first partition plate 341, the second partition plate 342 and the corresponding part of the connecting plate 340; a second accommodating space 345 is formed between the second partition plate 342, the third partition plate 343 and the corresponding part of the connecting plate 340; and a through hole is provided at the same position of the first partition plate 341, the second partition plate 342 and the third partition plate 343 (not shown, the same in the whole text). Among them, the rotating driving device 331 is fixed on the side of the third partition 343 away from the second partition 342, and then the rotating end of the rotating driving device 331 passes through the through hole of the third partition 343 to be connected with the coupling 332, and the coupling 332 is located in the second accommodating space 345; one end of the rotating shaft 333 is rotatably connected in the through hole of the first partition 341, and the other end of the rotating shaft 333 passes through the through hole of the second partition 342 to be connected with the coupling 332, and the rotating plate 334 is sleeved on the rotating shaft 333 located in the first accommodating space 344. In this way, the first accommodating space 344 and the second accommodating space 345 can effectively isolate the space between the coupling 332 and the rotating shaft 333 of the sleeve rotating plate 334, prevent accidental contact due to mechanical failure or improper operation, reduce potential injury risks, and protect the safety of workers and equipment; and the first accommodating space 344 and the second accommodating space 345 can reduce the mutual influence between the coupling 332 and the rotating shaft 333 of the sleeve rotating plate 334, prevent the vibration and force generated by the rotating drive device 331 during operation from being transmitted to each other between the coupling 332 and the rotating shaft 333 of the sleeve rotating plate 334, and improve the stability of the entire driving structure 33.

[0085] In this way, when it is necessary to open the small furnace door cover 32 relative to the small furnace door opening 31, the staff clicks start on the operation panel corresponding to the control unit. Then, when the control unit receives the opening signal sent by the operation panel, it will first start the push-pull drive device 335, so that the push-pull drive device 335 controls the small furnace door cover 32 to move away from the corresponding small furnace door opening 31. When the small furnace door cover 32 is no longer in contact with the corresponding small furnace door opening 31, the control center turns off the push-pull drive device 335 and starts the rotation drive device 331 at the same time. The driving device 331 controls the rotating plate 334 and the small furnace door cover 32 on the rotating plate 334 to move toward the outside away from the center of the small furnace door cover 32, so that the corresponding small furnace door mouth 31 is completely exposed, and the control unit closes the rotating driving device 331, and then the staff extends the carrier with the wafer to be processed into the small furnace door mouth 31 and places it in the vertical furnace, and then carries out the process, that is, introduces specific reaction gas into the vertical furnace, so as to realize specific coating, diffusion, oxidation and thin film deposition processes on the wafer to be processed.

[0086] When it is necessary to close the small furnace door cover 32 relative to the small furnace door opening 31, the staff clicks on the closing button on the operation panel corresponding to the control unit. Then, when the control unit receives the closing signal sent by the operation panel, the control unit will first start the rotation drive device 331, so that the rotation drive device 331 controls the rotation plate 334 and the small furnace door cover 32 located on the rotation plate 334 to move inward away from the center of the small furnace door cover 32 for reset. Then the control center turns off the rotation drive device 331 and starts the push-pull drive device 335 at the same time, so that the push-pull drive device 335 controls the small furnace door cover 32 to approach the corresponding small furnace door opening 31, until the second protrusion 321 of the small furnace door cover 32 matches and is inserted into the annular cavity 312 of the corresponding small furnace door opening 31, so that the small furnace door cover 32 completely covers the corresponding small furnace door opening 31, and then the control unit turns off the push-pull drive device 335.

[0087] like Figure 8 , Fig. 9As shown, a rectangular mounting plate 322 is further provided on one side of the small furnace door and furnace cover 32 facing the rotating plate 334, and the push-pull end of the push-pull driving device 335 is connected to the middle of the mounting plate 322, and the four sides of the mounting plate 322 are connected to the small furnace door and furnace cover 32 through the first guide column 323. The mounting plate 322 can share part of the weight and load between the small furnace door and furnace cover 32 and the push-pull driving device 335, thereby enhancing the stability and reliability of the overall structure; and the mounting plate 322 can also absorb the vibration and impact force generated when the small furnace door and furnace cover 32 rotates, so as to reduce the damage to the small furnace door and furnace cover 32 and the push-pull driving device 335 and extend their service life; and the mounting plate 322 can be connected to the small furnace door and furnace cover 32 through the first guide column 323, so that the relative position between the small furnace door and furnace cover 32 and the push-pull driving device 335 can be better adjusted, thereby ensuring the accuracy and stability of the rotation of the small furnace door and furnace cover 32. In addition, a plurality of weight-reducing holes 324 are provided on the mounting plate 322 , which can reduce the weight of the mounting plate 322 and enable the rotating drive device 331 and the push-pull drive device 335 to better control the movement of the small furnace door and furnace cover 32 .

[0088] A rectangular mounting area 336 is provided in the middle of the rotating plate 334, a push-pull driving device 335 is provided in the middle of the mounting area 336, and the four sides of the mounting area 336 are connected to the mounting plate 322 through second guide columns 337. The second guide columns 337 in this embodiment are illustrated by being installed at the four corners of the mounting area 336. The second guide columns 337 can ensure that the relative positions between the mounting plate 322 and the small furnace door and furnace cover 32 are accurately aligned, so that during the rotation of the small furnace door and furnace cover 32, the second guide columns 337 can guide the mounting plate 322 and the small furnace door and furnace cover 32 to move along a predetermined path to prevent them from deviating from the correct position or offset, which helps to maintain the stability and accuracy of the rotation of the small furnace door and furnace cover 32.

[0089] Embodiment 2:

[0090] Please also read Fig.11 , Fig.12 The vertical furnace provided in this embodiment includes an upper furnace cover 2, a lower furnace door 3, an outer furnace tube 13, an inner furnace tube 14, a carrier boat bearing device 15 and a driving device 16.

[0091] In this embodiment, the upper furnace cover 2 and the lower furnace door 3 are arranged opposite to each other, the outer furnace tube 13 is arranged between the upper furnace cover 2 and the lower furnace door 3, and the inner furnace tube 14 is arranged on the inner side of the outer furnace tube 13. At the same time, the inner furnace tube 14 and the outer furnace tube 13 are arranged coaxially. The lower end of the outer furnace tube 13 is an open end, and the lower furnace door 3 is arranged at the open end of the outer furnace door. The lower end of the inner furnace tube 14 is a closed end, and a distance is maintained between the lower end of the inner furnace tube 14 and the lower furnace door 3. At this time, the inner furnace tube 14, the outer furnace tube 13, the upper furnace cover 2 and the lower furnace door 3 together constitute a receiving cavity with a concave cross-section. The carrier boat carrying device 15 is rotatably disposed in the accommodating cavity, and the carrier boat carrying device 15 is used to carry the carrier boat 17. The driving device 16 is disposed on the side of the lower furnace door 3 away from the accommodating cavity, and the driving device 16 is connected to the carrier boat carrying device 15. The driving device 16 is used to drive the carrier boat carrying device 15 to rotate in the accommodating cavity, thereby driving the carrier boat 17 disposed on the carrier boat carrying device 15 to rotate synchronously, thereby making the silicon wafers on the carrier boat 17 heated evenly.

[0092] In this embodiment, if Fig.12 , Fig.13 As shown, the carrier boat bearing device 15 includes a second rotating base 81, a rotating connecting member 83 and a second bearing member 82. The second rotating base 81 is placed in the accommodating cavity and sleeved on the outer side of the inner furnace tube 14. The second rotating base 81 is provided with a plurality of bearing positions for the carrier boat 17 to pass through. The rotating connecting member 83 is located between the closed end of the inner furnace tube 14 and the lower furnace door 3 and connects the second rotating base 81 with the driving device 16. The second bearing member 82 is used to carry the carrier boat 17. The second bearing member 82 is provided with a plurality of pairs. Each pair of second bearing members 82 is located on both sides of a bearing position and is foldably arranged on the second rotating base 81. It should be noted that the carrier boats 17 of this embodiment are stacked on each other without hanging. By rotating the entire second rotating base 81, the carrier boat 17 on the second rotating base 81 rotates in the reaction chamber formed by the outer furnace tube 13 and the inner furnace tube 14.

[0093] Specifically, the carrier boat bearing device 15 includes a second rotating base 81, a second bearing member 82 and a rotating connecting member 83. The rotating connecting member 83 includes a fixed connecting portion, a heat insulating portion and a rotating connecting portion. The heat insulating portion is filled with heat insulating materials. Such a design can prevent the heat in the vertical furnace from being transferred to the lower furnace door 3, protect the lower furnace door 3 and the driving device 16 and other parts, and also reduce the energy loss in the vertical furnace. The fixed connecting portion and the rotating connecting portion are respectively arranged on the upper and lower sides of the heat insulating portion. The fixed connecting portion is connected to the second rotating base 81, and the rotating connecting portion is connected to the driving device 16. Among them, six bearing positions arranged in a circular shape are provided on the second rotating base 81, and two second bearing members 82 with a folded state and an unfolded state are correspondingly arranged at each bearing position. The two second bearing members 82 form a pair of second bearing members 82. Each second bearing member 82 includes a bearing fixed portion 821 and a bearing movable portion 822. The bearing fixed portion 821 is fixedly arranged on the second rotating base 81, and the bearing movable portion 822 is rotatably arranged on the bearing fixed portion 821. In any two adjacent pairs of bearing members 82, a bearing fixing portion 821 belonging to one pair of bearing members 82 is connected to a bearing fixing portion 821 belonging to the other pair of bearing members 82. In practical applications, in any two adjacent pairs of bearing members 82, the two mutually connected bearing fixing portions 821 can be integrally formed. Such a design can reduce the number of parts and save installation time.

[0094] Taking the rotation angle of the bearing movable part 822 in each bearing member 82 as 90 degrees as an example, the bearing fixed part 821 is always in a horizontal setting. When the second bearing member 82 is in a folded state, the bearing movable part 822 is vertically arranged with the bearing fixed part 821. When the second bearing member 82 is in an unfolded state, the bearing movable part 822 is also in a horizontal setting. Taking the taking and placing of a carrier boat 17 as an example, if the carrier boat 17 is to be placed, the two second bearing members 82 are switched to a folded state so that the carrier boat 17 can pass through the bearing position. When the bottom of the carrier boat 17 moves to the bearing position, the two bearing members 82 are switched to an unfolded state so that the carrier boat 17 is placed on the bearing member. If the carrier boat 17 is to be taken out later, the two bearing members 82 are switched to a folded state so that the carrier boat 17 can pass through the bearing position, thereby realizing the taking and placing of the carrier boat 17.

[0095] In this embodiment, if Fig.12As shown, the driving device 16 is arranged on the side of the lower furnace door 3 away from the accommodating chamber. The driving device 16 includes a magnetic fluid sealing component 161, a belt 162 and a motor 163. The magnetic fluid sealing component 161 includes a transmission shaft, one end of which is connected to the motor 163 through the belt 162, and the other end is connected to the rotating connector 83 in the carrier boat bearing device 15. The motor 163 drives the carrier boat bearing device 15 to rotate, thereby driving the carrier boat 17 stacked on the carrier boat bearing device 15 to rotate together. It should be noted that the magnetic fluid sealing component 161 includes a fixed seat and a transmission shaft arranged on the inner side of the fixed seat, and two magnetic poles are arranged on the outer side of the transmission shaft along the axial direction thereof, and a permanent magnet is arranged between the two magnetic poles. There is a gap between the two magnetic poles and the transmission shaft, and the gap is filled with magnetic fluid. Magnetic fluid is a colloidal liquid combined with solid and liquid, which is made of magnetic nanoparticles, which are evenly dispersed into a liquid (carrier liquid) with a very low saturated vapor pressure after special treatment, and is mixed with the liquid by a dispersant and does not precipitate or solidify. It has both the fluidity of liquid and magnetism. Magnetic fluid vacuum dynamic seal is realized based on this characteristic. Magnetic fluid seal assembly 161 utilizes the characteristics of magnetic fluid, and uses magnets to fix the magnetic fluid around the shaft to form a liquid "O-ring". Through the connection between the magnetic fluid seal assembly 161 and the rotatable carrier boat bearing device 15, under the premise of ensuring that power can be transmitted, the furnace will not lose pressure and the process gas will not leak out.

[0096] It should be noted that the specific structures of the upper furnace cover 2, the lower furnace door 3, the outer furnace tube 13 and the inner furnace tube 14 in this embodiment are the same as those in the previous embodiment and will not be described in detail here.

[0097] In the description of the utility model, it should be noted that when an element is referred to as "fixed to" or "set to" another element, it can be directly on the other element or indirectly on the other element. When an element is referred to as "connected to" another element, it can be directly connected to the other element or indirectly connected to the other element. It should be understood that the orientation or position relationship indicated by the terms "center", "length", "width", "thickness", "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like is based on the orientation or position relationship shown in the drawings, which is only for the convenience of describing the utility model and simplifying the description, rather than indicating or implying 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 of the utility model. In addition, the terms "first" and "second" are only used for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, the features defined as "first" and "second" can explicitly or implicitly include one or more of the features. In the description of the present invention, "plurality" means two or more than two, unless otherwise clearly and specifically defined.

[0098] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A vertical furnace, characterized in that: The invention comprises an upper furnace cover, a lower furnace door, an outer furnace tube and an inner furnace tube which enclose and form a receiving cavity, wherein the upper furnace cover and the lower furnace door are respectively arranged at the upper and lower ends of the outer furnace tube, the inner furnace tube is arranged on the inner side of the outer furnace tube, and one end of the inner furnace tube close to the lower furnace door is a closed end and a distance is maintained between the closed end and the lower furnace door; A rotatable boat carrier device for carrying the boat is provided in the accommodating chamber, and a driving device for driving the boat carrier device to rotate is provided on a side of the lower furnace door away from the accommodating chamber.

2. The vertical furnace according to claim 1, characterized in that: The carrier boat carrying device comprises: a first rotating base, located between the closed end of the inner furnace tube and the lower furnace door; A rotating shaft connected to the driving device and arranged on one side of the first rotating base; The first bearing member is used for bearing the carrier boat, is arranged on the other side of the first rotating base, and is sleeved on the outer side of the inner furnace tube.

3. The vertical furnace according to claim 2, characterized in that: The driving device comprises: A motor is arranged on a side of the lower furnace door away from the accommodating cavity; The magnetic fluid sealing component comprises a transmission shaft, one end of which is connected to the motor through a belt, and the other end of which is connected to the rotating shaft.

4. The vertical furnace according to claim 2, characterized in that: The first bearing member includes a plurality of hanging plates arranged at intervals on the first rotating base, and each hanging plate is provided with a hook hole for being hung by a hook on the carrier boat.

5. The vertical furnace according to claim 4, characterized in that: The carrier boat bearing device also includes: a first heat insulating member, which is arranged on the first rotating base and has a central area thereof provided with a plurality of limiting holes for the plurality of hanging plates to pass through.

6. The vertical furnace according to claim 4, characterized in that: The carrier boat bearing device further includes: a second heat insulating member, which is arranged on the first rotating base and has a plurality of notches in its edge area for the plurality of hanging plates to pass through.

7. The vertical furnace according to claim 1, characterized in that: The carrier boat carrying device comprises: A second rotating base is placed in the accommodating cavity and sleeved on the outer side of the inner furnace tube, and the second rotating base is provided with a plurality of bearing positions for the carrier boat to pass through; A rotating connecting member, located between the closed end of the inner furnace tube and the lower furnace door, connecting the second rotating base and the driving device; A plurality of pairs of second bearing members are used to bear the carrier boat, each pair of bearing members is located at two sides of a bearing position and is foldably arranged on the second rotating base.

8. The vertical furnace according to claim 7, characterized in that: The driving device comprises: A motor is arranged on a side of the lower furnace door away from the accommodating cavity; The magnetic fluid sealing component comprises a transmission shaft, one end of which is connected to the motor through a belt, and the other end of which is connected to the rotating connecting piece.

9. The vertical furnace according to claim 7, characterized in that: Each second bearing member in each pair of second bearing members comprises a bearing fixed portion and a bearing movable portion, the bearing fixed portion is fixedly arranged on the second rotating base, and the bearing movable portion is rotatably arranged on the bearing fixed portion.

10. The vertical furnace according to claim 1, characterized in that: The upper end surface of the upper furnace cover away from the accommodating cavity protrudes upward to form a spherical protrusion.

11. The vertical furnace according to claim 10, characterized in that A central hole for the inner furnace tube to pass through is provided in the middle of the upper furnace cover, a cavity is provided inside the upper furnace cover around the central hole, and a plurality of cavity ribs connected between the upper and lower inner walls of the cavity are provided in the cavity.

12. The vertical furnace according to claim 11, characterized in that The upper furnace cover also includes a lower plate, an outer plate and an inner plate which cooperate with the upper end surface to enclose the cavity. The lower plate, the outer plate and the inner plate are all hollow plates to form a water flow channel or a wind flow channel.

13. The vertical furnace according to claim 11, characterized in that One end of the inner furnace pipe passing through the central hole of the upper furnace cover is provided with a connector for hoisting.

14. The vertical furnace according to claim 1, characterized in that: The lower furnace door can be arranged to cover the lower end of the outer furnace tube.

15. The vertical furnace according to claim 1, characterized in that: The lower furnace door is provided with a small furnace door, and the small furnace door includes a small furnace door opening that passes through the lower furnace door, and a small furnace door cover corresponding to the small furnace door opening, and the small furnace door cover is connected to a driving structure, and the driving structure is used to drive the small furnace door cover to open or close relative to the small furnace door opening.

16. The vertical furnace according to claim 1, characterized in that: There are a plurality of carrier boats, which are arranged in a circular manner and spaced apart in the accommodating chamber of the vertical furnace.

17. The vertical furnace according to claim 1, characterized in that: An inner heating element is arranged on the inner side of the inner furnace tube, and an outer heating element is arranged on the outer side of the outer furnace tube. Both the inner heating element and the outer heating element are composed of a plurality of independent heating sections.

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