Vertical furnace

Abstract

The present invention provides a vertical furnace. The vertical furnace comprises an upper furnace cover, a lower furnace door, an outer furnace tube, and an inner furnace tube which define an accommodating cavity, wherein the upper furnace cover and the lower furnace door are arranged at an upper end and a lower end of the outer furnace tube, respectively, the inner furnace tube is arranged on the inner side of the outer furnace tube, the end of the inner furnace tube close to the lower furnace door is a closed end, and a distance is kept between the closed end and the lower furnace door; and a rotatable carrier boat bearing device for bearing a carrier boat is provided in the accommodating cavity in the vertical furnace, and the side of the lower furnace door away from the accommodating cavity is provided with a driving device for driving the carrier boat bearing device to rotate. The rotatable carrier boat bearing device for bearing the carrier boat is provided, and the driving device drives the carrier boat bearing device to rotate inside the accommodating cavity and thus drives the carrier boat borne by the carrier boat bearing device to rotate synchronously, so that the vertical furnace provided by the present invention improves heating uniformity of a silicon wafer on the carrier boat.

Description

Vertical furnace TECHNICAL FIELD

[0001] The present application belongs to the technical field of equipment for manufacturing semiconductors, and more particularly to a vertical furnace. BACKGROUND

[0002] In the current diffusion of the photovoltaic industry, oxidation, annealing, doping, PECVD (low pressure chemical vapor deposition), LPCVD (plasma enhanced chemical vapor deposition) and other processes have vertical furnaces and horizontal furnaces. The structures of these two types of furnaces both need to load silicon wafers into specific carriers and transfer them into the reaction cavity for processing. By introducing specific reaction gases, specific film coating, diffusion, oxidation and thin film deposition processes on silicon wafers are realized. In the existing two-layer furnace tube design, the base and top wall are used to seal the two ends of the double-layer furnace tube to form a straight-through cavity. The silicon wafers to be processed are 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 furnace tube with the above structure has the following problems: the structure of the carrier boat is fixed and cannot be adjusted in position and angle. This placement method can cause local non-uniformity of the gas field and the thermal field when the reaction gas is introduced or the temperature is raised, resulting in poor uniformity when the silicon wafers react at high temperatures, affecting the overall process yield, and causing the battery pieces produced in the same batch to be of different quality. SUMMARY

[0004] The present application aims to provide a vertical furnace to solve the problem of uneven heating of silicon wafers on the carrier boat due to the fixed position of the carrier boat in the prior art.

[0005] To achieve the above-mentioned purpose, the technical solution adopted by the present application is as follows: a vertical furnace is provided, which comprises an upper furnace cover, a lower furnace door, an outer furnace tube and an inner furnace tube forming a containing cavity. 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 the 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 carrier boat carrying device for carrying the carrier boat is arranged in the containing cavity and can rotate. The side of the lower furnace door away from the containing cavity is provided with a driving device for driving the carrier boat carrying device to rotate.

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

[0008] A first rotating base is arranged between the closed end of the inner furnace tube and the lower furnace door.

[0009] a rotating shaft, connected with the driving device, arranged on one side of the first rotating base;

[0010] a first carrier, arranged on the other side of the first rotating base and sleeved on the outside of the inner furnace tube, for carrying the carrier boat.

[0011] Further, the driving device comprises:

[0012] a motor, arranged on the side of the lower furnace door away from the containing cavity;

[0013] a magnetic fluid sealing assembly, comprising a transmission shaft, one end of which is connected with the motor through a belt and the other end of which is connected with the rotating shaft.

[0014] Further, the first carrier comprises a plurality of hanging plates arranged on the first rotating base at intervals, each of which is provided with a hook hole for the hook on the carrier boat to hang on.

[0015] Further, the carrier boat carrying device further comprises a first heat insulation member arranged on the first rotating base and provided with a plurality of limiting holes in the central region for the plurality of hanging plates to pass through.

[0016] Further, the carrier boat carrying device further comprises a second heat insulation member arranged on the first rotating base and provided with a plurality of notches in the edge region for the plurality of hanging plates to pass through.

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

[0018] a second rotating base, arranged in the containing cavity and sleeved on the outside of the inner furnace tube, provided with a plurality of carrier positions for the carrier boat to pass through;

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

[0020] a plurality of pairs of second carriers, for carrying the carrier boat, each pair of carriers being arranged on the two sides of one carrier position and foldably arranged on the second rotating base.

[0021] Further, the driving device comprises:

[0022] a motor, arranged on the side of the lower furnace door away from the containing cavity;

[0023] a magnetic fluid sealing assembly, comprising a transmission shaft, one end of which is connected with the motor through a belt and the other end of which is connected with the rotating connecting member.

[0024] Further, each of the second carriers in each pair of second carriers comprises a carrier fixed part and a carrier movable part, the carrier fixed part is fixedly arranged on the second rotating base, and the carrier movable part is rotatably arranged on the carrier fixed part.

[0025] Further, the upper furnace cover is convex upward to form a spherical protrusion away from the upper end of the accommodating cavity.

[0026] Further, the upper furnace cover is convex upward to form a spherical protrusion away from the upper end of the accommodating cavity.

[0027] Further, the upper furnace cover further comprises a lower layer plate, an outer layer plate and an inner layer plate which cooperate with the upper end surface to form the cavity, and the lower layer plate, the outer layer plate and the inner layer plate are all hollow layer plates to form water flow channels or air flow channels.

[0028] Further, the inner furnace tube is provided with a connector at one end of the central hole of the upper furnace cover for hoisting.

[0029] Further, the lower furnace door is arranged at the lower end of the outer furnace tube.

[0030] Further, the lower furnace door is arranged at the lower end of the outer furnace tube.

[0031] Further, the carrier boats are arranged in the accommodating cavity of the vertical furnace in a ring shape.

[0032] Further, the inner furnace tube is provided with an inner heating element on the inner side, and the outer furnace tube is provided with an outer heating element on the outer side, and the inner heating element and the outer heating element are both composed of multiple independent heating sections.

[0033] The vertical furnace provided by the present application has the following beneficial effects compared with the prior art: by arranging the carrier boat carrier device which can rotate for carrying the carrier boats in the accommodating cavity of the vertical furnace, and driving the carrier boat carrier device to rotate through the driving device, the carrier boat carrier device and the carrier boats carried thereby are driven to rotate, and the uniformity of the heating of the silicon wafers on the carrier boats is improved. BRIEF DESCRIPTION OF DRAWINGS

[0034] In order to make the technical solutions in the embodiments of the present application clearer, the accompanying drawings needed in the embodiments or prior art description will be briefly introduced. Obviously, the accompanying drawings in the following description only show some embodiments of the present application, and other drawings can be obtained by those skilled in the art without any creative effort.

[0035] Fig. 1 is a structural schematic view of a vertical furnace according to an embodiment of the present application;

[0036] Fig. 2 is a sectional view along A-A in Fig. 1;

[0037] Fig. 3 is a structural schematic view of a carrier boat carrying device according to an embodiment of the present application;

[0038] Fig. 4 is another structural schematic view of the carrier boat carrying device according to an embodiment of the present application;

[0039] Fig. 5 is a top view of a heating element and a heat dissipating element cooperating with inner and outer furnace tubes according to an embodiment of the present application;

[0040] Fig. 6 is a structural schematic view of a lower furnace door provided with a small furnace door according to an embodiment of the present application;

[0041] Fig. 7 is a partial structural schematic view of a lower furnace door with a thick furnace cover without a small furnace door according to an embodiment of the present application;

[0042] Fig. 8 is a side view of Fig. 7;

[0043] Fig. 9 is a structural schematic view of a small furnace door furnace cover cooperating with a driving structure according to an embodiment of the present application;

[0044] Fig. 10 is a side view of Fig. 9;

[0045] Fig. 11 is a structural schematic view of a vertical furnace according to another embodiment of the present application;

[0046] Fig. 12 is a sectional view along B-B in Fig. 11;

[0047] Fig. 13 is a structural schematic view of a carrier boat carrying device according to another embodiment of the present application;

[0048] In the drawings, the main marks are as follows:

[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, reinforcing rib; 22, lower layer plate; 23, inner layer plate; 24, outer layer plate; 25, connector;

[0051] 3, lower furnace door; 31, small furnace door furnace mouth; 311, first protrusion; 312, annular cavity;

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

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

[0054] 41, fixed ring; 42, first rotary base; 47, rotating shaft; 43, first bearing; 491, first heat insulation member; 492, second heat insulation 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 rotary base; 82, second bearing; 83, rotary connecting piece; 821, bearing fixed part; 822, bearing movable part. DETAILED DESCRIPTION

[0057] In order to make the technical problems to be solved by the present application, technical solutions and beneficial effects more clear and explicit, the present application will be further described in detail below in combination with the drawings and examples. It should be understood that the specific examples described herein are only used to explain the present application, and are not used to limit the present application. Example one:

[0058] For the convenience of understanding, the following direction is explained first, the axial direction of the vertical furnace is the up-down direction, and the radial direction of the vertical furnace is the inner-outer direction.

[0059] Please refer to Fig. 1 and Fig. 2, the vertical furnace provided by the present 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 drive device 16.

[0060] In the embodiment, the upper furnace cover 2 and the lower furnace door 3 are oppositely arranged, 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 inside the outer furnace tube 13, and the inner furnace tube 14 is coaxially arranged 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 jointly form a containing cavity with a concave cross section. The carrier boat bearing device 15 is rotatably arranged in the containing cavity, and the carrier boat bearing device 15 is used for bearing the carrier boat 17. The driving device 16 is arranged on the side of the lower furnace door 3 away from the containing cavity, and the driving device 16 is connected with the carrier boat bearing device 15. The driving device 16 is used for driving the carrier boat bearing device 15 to rotate in the containing cavity, so as to drive the carrier boat 17 arranged on the carrier boat bearing device 15 to synchronously rotate, and then make the silicon wafers on the carrier boat 17 uniformly heated.

[0061] In the embodiment, please refer to FIG. 2, FIG. 3, and FIG. 4, the carrier boat bearing device 15 comprises 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, and the rotating shaft 47 is connected with 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 outside of the inner furnace tube 14, and the first bearing member 43 is used for bearing the carrier boat 17.

[0062] In a specific example of the embodiment, as shown in FIG. 2 and FIG. 3, the carrier boat bearing device 15 comprises the first rotating base 42, a first heat insulation member 491, a fixed ring 41, the first bearing member 43, and the rotating shaft 47. The first rotating base 42 is spaced apart from and parallel to the fixed ring 41. The first bearing member 43 comprises a plurality of hanging plates which are arranged in a ring shape between the first rotating base 42 and the fixed ring 41, and the plurality of hanging plates are fixed at the edges of the first rotating base 42. At least one hook hole for hanging the carrier boat 17 is arranged in the height direction of the hanging plate, and the carrier boat 17 can be a vertical quartz boat. The first heat insulation 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. One side of the first heat insulation member 491 facing the first rotating base 42 is an open end, and the first heat insulation member 491 forms a containing cavity with the first rotating base 42. The containing cavity is filled with heat insulation material. By arranging the first heat insulation member 491 and the heat insulation material, the heat in the vertical furnace can be blocked from being transmitted 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. On the other hand, the energy loss in the vertical furnace can be reduced. The edge region of the first heat insulation member 491 is further provided with a plurality of gaps which are spaced apart. The arrangement of the gaps can provide favorable conditions for installing the hanging plates.

[0063] In another specific example of the embodiment, as shown in FIG. 4, the carrier boat carrying device 15 includes a first rotating base 42, a second heat insulation member 492, a fixed ring 41, a first carrying member 43, and a rotating shaft (not labeled in the figure). The first rotating base 42 is spaced apart from and parallel to the fixed ring 41, and the first carrying member 43 includes four hanging plates arranged in a ring shape between the first rotating base 42 and the fixed ring 41, while the first carrying member 43 is fixed at the center region of the first rotating base 42. At least one hook hole for suspending the carrier boat 17, which can be a vertical quartz boat, is arranged in the height direction of the hanging plate. The second heat insulation 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 insulation member 492 facing the first rotating base 42 is an open end, and the second heat insulation member 492 forms a containing cavity with the first rotating base 42. The containing cavity is filled with heat insulation material, which can block the heat in the vertical furnace from being transmitted to the lower furnace door 3 through the first rotating base 42. On the one hand, this can protect the lower furnace door and the driving device and other parts, and on the other hand, it can also reduce the energy loss in the vertical furnace. The center region of the second heat insulation member 492 is also provided with a plurality of limiting holes for the hanging plates to pass through, and the limiting holes provide favorable conditions for installing the hanging plates.

[0064] In the embodiment, as shown in FIGS. 2 and 3, the driving device 16 is arranged on the side of the lower furnace door 3 away from the containing cavity. The driving device 16 includes a magnetic fluid sealing assembly 161, a belt 162, and a motor 163. The magnetic fluid sealing assembly 161 includes a transmission shaft, one end of which is connected to the motor 163 through the belt 162, and the other end of which is connected to the rotating shaft 47 in the carrier boat carrying device 15. The carrier boat carrying device 15 is driven to rotate by the motor 163, thereby driving the carrier boat 17 suspended thereon to rotate together. It should be noted that the magnetic fluid sealing assembly 161 includes a fixed seat and a transmission shaft arranged inside the fixed seat. Two magnetic poles are arranged on the outside of the transmission shaft in the axial direction, 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. The magnetic fluid is a colloidal liquid that combines solid and liquid phases, which is uniformly dispersed in a liquid (carrier liquid) with very low saturated vapor pressure by special treatment, and does not precipitate or solidify after mixing with the liquid through a dispersing agent. It has both the fluidity of a liquid and magnetism. The magnetic fluid vacuum dynamic sealing is realized based on this characteristic. The magnetic fluid sealing assembly 161 uses the characteristics of the magnetic fluid to fix the magnetic fluid around the shaft by the magnet, forming a liquid "O-shaped sealing ring". Through the connection of the magnetic fluid sealing assembly 161 and the rotatable carrier boat carrying device 15, the pressure in the furnace can be maintained and the process gas can not be leaked out under the premise that the power can be transmitted.

[0065] In the embodiment, as shown in FIG. 2, 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, and the connector 25 is configured to enable the inner furnace tube 14 to be connected with a hoisting connector outside, which can provide force to the inner furnace tube 14 to ensure that the inner furnace tube 14 is suspended inside the outer furnace tube 13. The hoisting connector is not limited to a stake or the like provided on the ceiling. The lower end of the inner furnace tube 14 is a closed end and is hemispherical. By configuring the lower end of the outer furnace tube 13 to be hemispherical, greater pressure can be borne, and the inner furnace tube 14 is more suitable for the requirement of vacuumizing the inside of the vertical furnace. The inner furnace tube 14 can be 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 cavity, which is part of the aforementioned containing cavity. When the carrier boat 17 enters the inside of the vertical furnace, the carrier boat 17 is mainly placed in the reaction cavity.

[0066] In the embodiment, as shown in FIG. 2, the upper furnace cover 2 is provided at the upper end of the outer furnace tube 13, and the upper furnace cover 2 is sealingly connected with the outer furnace tube 13. The central hole of the upper furnace cover 2 is provided with a central hole through which the inner furnace tube 14 passes, and the central hole of the upper furnace cover 2 and the upper end (open end) of the inner furnace tube 14 form a concentric circle in a top view. The upper end of the upper furnace cover 2 is convex and spherical in shape, which can enable the upper furnace cover 2 to bear greater pressure and prevent the upper furnace cover 2 from being sucked in when the inside of the vertical furnace is vacuumized. The inside of the upper furnace cover 2 around the central hole is provided with a cavity, and the upper furnace cover 2 further includes a lower layer plate 22, an inner layer plate 23, and an outer layer plate 24 which cooperate with the upper end face to form the aforementioned cavity. A plurality of reinforcing ribs 21 are arranged between the upper and lower inner walls of the cavity and are connected with the cavity. The reinforcing ribs 21 are all plate-shaped and are provided with a plurality of through holes on the plate surface. The reinforcing ribs 21 are arranged in a ring shape in the annular cavity. The reinforcing ribs 21 can enhance the pressure resistance of the outer furnace cover. A water cooling assembly or an air cooling assembly can also be arranged in the upper furnace cover 2. The lower layer plate 22, the inner layer plate 23, and the outer layer plate 24 are all hollow layer plates to form water flow channels or air flow channels. During the operation of the vertical furnace, water or air can be used to continuously take away excess heat, thereby facilitating temperature control in the vertical furnace.

[0067] In the embodiment, as shown in FIG. 2 and FIG. 5, the inner furnace tube 14 and the outer furnace tube 13 are both provided with heating elements to heat the containing 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, which 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, which is referred to as the outer heating element 71 hereinafter. The inner heating element 72 and the outer heating element 71 can be selected from heating wires, infrared lamp tubes, electromagnetic induction heating and the like. The outer heating element 71 and the inner heating element 72 are independently controlled to form a high-temperature environment required for the reaction of the silicon wafer.

[0068] In a specific example of the embodiment, the inner heating element 72 covers the entire inner side of the inner furnace tube 14. The inner heating element 72 is formed by uniformly winding heating wires 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. The outer heating element 71 is formed by uniformly winding heating wires along the axial direction of the outer furnace tube 13.

[0069] In another specific example of the embodiment, the inner heating element 72 is composed of a plurality of first independent heating sections. Each first independent heating section is formed by winding heating wires along the axial direction of the inner furnace tube 14. The distribution density of the heating wires in different first independent heating sections can be the same or different. Similarly, the outer heating element 71 is composed of a plurality of second independent heating sections. Each second independent heating section is formed by winding heating wires along the axial direction of the outer furnace tube 13. The distribution density of the heating wires in different first independent heating sections can be the same or different. In the example, the inner heating element 72 and the outer heating element 71 are both composed of a plurality of independent heating sections, i.e., the inner heating element 72 is composed of a plurality of first independent heating sections, and the outer heating element 71 is composed of a plurality of second independent heating sections, to realize independent control of the inner and outer heating elements in different zones and / or layers.

[0070] In the embodiment, as shown in FIG. 2 and FIG. 5, the inner furnace tube 14 and the outer furnace tube 13 can be provided with heat dissipation elements to quickly and stably adjust the temperature of the inner and outer furnace tubes 13. Specifically, the inner side of the inner furnace tube 14 is provided with a first heat dissipation element 73. Meanwhile, the first heat dissipation element 73 can be independently arranged from the inner heating element 72, or the first heat dissipation element 73 can be integrally arranged with the inner heating element 72. Similarly, the outer side of the outer furnace tube 13 is provided with a second heat dissipation element 74. Meanwhile, the second heat dissipation element 74 can be independently arranged from the outer heating element 71, or the second heat dissipation element 74 can be integrally arranged with the outer heating element 71. The first and second heat dissipation elements can adopt air cooling structure or water cooling structure, but are not limited to the above structures, and any mechanism with heat exchange and heat dissipation functions is included in the scope. The first and second heat dissipation elements can be manually controlled or automatically controlled by collecting temperature signals, pressure signals, etc. Any automatic control method is included in the scope.

[0071] In the embodiment, as shown in FIG. 2, the outer furnace tube 13 is provided with a water cooling joint 75 at the connecting position with the lower furnace door 3, which is used to supply water to the heat dissipation element arranged inside. The inner furnace tube 14 and the outer furnace tube 13 can also be provided with water flow channels or air flow channels, or the heating elements inside the inner furnace tube 14 and the outer furnace tube 13 can also be provided with water flow channels or air flow channels, to better control the temperature in the vertical furnace.

[0072] In the embodiment, the lower furnace door 3 can adopt an integrated furnace door or a split furnace door.

[0073] In a specific example of the embodiment, the lower furnace door 3 adopts an integrated furnace door, i.e., 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 carriers boats 17 in the containing cavity can be taken out. In addition, the side of the lower furnace door 3 close to the containing cavity of the vertical furnace is a spherical protruding structure, which can make the lower furnace door 3 bear greater pressure and prevent it from being sucked in when the vertical furnace is vacuumized.

[0074] In another specific example of the embodiment, as shown in FIG. 2 and FIG. 6 to FIG. 10, the lower furnace door 3 is provided with small furnace doors, which include small furnace door openings 31 and small furnace door covers 32. The small furnace door covers 32 are connected with driving structures 33, which are used to drive the small furnace door covers 32 to open or close relative to the small furnace door openings 31. When there are multiple small furnace doors, the multiple small furnace doors can be arranged in a circular ring or randomly arranged without rules, as long as the small furnace doors do not interfere with other parts of the vertical furnace.

[0075] Compared with the previous example, the lower furnace door 3 adopts the scheme of an integrated furnace door, which is easy to cause heat loss in the vertical furnace to the atmosphere, and needs to be heated from room temperature again during the second batch of silicon wafer processing, thereby increasing energy consumption and cost. The lower furnace door 3 adopts the scheme of being provided with a plurality of small furnace doors, which causes the smallest heat loss under the premise of ensuring that the carrier boat 17 can normally pass through the small furnace door.

[0076] As shown in FIG. 7, in order to make the small furnace door furnace cover 32 better fit the corresponding small furnace door furnace port 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 furnace cover 32. The first protrusion 311 forms an annular cavity 312 around the small furnace door furnace port 31 in the circumferential direction, and the small furnace door furnace port 31 is completely located in the annular cavity 312. At the same time, the shape of the small furnace door furnace port 31 is matched with the shape of the side surface of the carrier boat 17, and meets the condition that the small furnace door furnace port 31 can normally pass through the carrier boat 17.

[0077] As shown in FIGS. 6, 8, the lower furnace door 3 is provided with a spherical protruding structure, which can make the lower furnace door 3 bear greater pressure and prevent it from being sucked in when the vertical furnace is internally vacuumized. It should be noted that, due to the spherical protruding structure of the lower furnace door 3, the place where the first protrusion 311 contacts the lower furnace door 3 is uneven, but the position where the first protrusion 311 cooperates with the small furnace door furnace cover 32 is horizontal.

[0078] As shown in FIGS. 7, 9, 10, the small furnace door furnace cover 32 matching the small furnace door furnace port 31 is provided with a second protrusion 321 on the side facing the small furnace door furnace port 31, which can be matched and inserted into the annular cavity 312. Of course, in order to further improve the sealing performance between the small furnace door furnace cover 32 and the corresponding small furnace door furnace port 31, a high-temperature-resistant sealing strip can also be provided around the second protrusion 321.

[0079] The first protrusion 311 and the second protrusion 321 are both circular rings, which can make the small furnace door furnace cover 32 quickly cover the small furnace door furnace port 31, and only the centers of the first protrusion 311 and the second protrusion 321 need to be aligned. If the first protrusion 311 and the second protrusion 321 are provided in other shapes, the outer side of the first protrusion 311 and the inner side of the second protrusion 321 need to be strictly aligned.

[0080] As shown in FIG. 9 and FIG. 10, the driving structure 33 comprises a rotating driving device 331, a shaft coupling 332, a rotating shaft 333, a rotating plate 334, a push-pull driving device 335 and a connecting plate 340. The rotating driving device 331 is preferably a rotating motor, and the push-pull driving device 335 is preferably a push-pull motor. The rotating 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 for electrical connection with a control unit for controlling the furnace door structure.

[0081] As shown in FIG. 6, FIG. 9 and FIG. 10, the lower furnace door 3 is provided with the rotating driving device 331 corresponding to each small furnace door opening 31 on one side. The rotating end of the rotating driving device 331 is connected with the rotating shaft 333 through the shaft coupling 332. The end of the rotating shaft 333 is connected with the rotating plate 334 which can rotate. The rotating plate 334 is located in front of the small furnace door opening 31. The shaft coupling 332 can firmly connect the rotating end of the rotating driving device 331 and the rotating shaft 333, so that the rotating end of the rotating driving device 331 and the rotating shaft 333 rotate together and transmit torque and motion, so as to ensure that the relative position between the rotating end of the rotating driving device 331 and the rotating shaft 333 remains unchanged during the transmission of motion and power, so as to realize reliable transmission. The shaft coupling 332 can also compensate for the deviation of the rotating end of the rotating driving device 331 and the rotating shaft 333, so as to ensure the continuity and stability of the transmission. The shaft coupling 332 can also absorb impact and vibration, reduce the wear and failure risk of the rotating end of the rotating driving device 331 and the rotating shaft 333, and improve the stability and reliability of the driving structure 33.

[0082] The middle part of the rotating plate 334 is bolted with the push-pull driving device 335. The push-pull end of the push-pull driving device 335 penetrates through the rotating plate 334 and is connected with the small furnace door cover 32.

[0083] The driving structure 33 further comprises a first partition plate 341 and a second partition plate 342 which are arranged at one end of the connecting plate 340, a third partition plate 343 which is arranged at the other end of the connecting plate 340, a first accommodating space 344 which 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 which 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 (not shown) which is arranged at the same position of the first partition plate 341, the second partition plate 342 and the third partition plate 343. The rotating driving device 331 is fixed at the side of the third partition plate 343 which is away from the second partition plate 342, and then the rotating end of the rotating driving device 331 is connected with the coupling 332 through the through hole of the third partition plate 343, 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 plate 341, and the other end of the rotating shaft 333 is connected with the coupling 332 through the through hole of the second partition plate 342, and the rotating plate 334 is sleeved on the rotating shaft 333 which is 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 which is sleeved with the rotating plate 334, can prevent accidental contact due to mechanical failure or improper operation, reduce the potential risk of injury, and protect the safety of the workers and the equipment. 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 which is sleeved with the rotating plate 334, prevent the vibration and force generated when the rotating driving device 331 works from being transmitted between the coupling 332 and the rotating shaft 333 which is sleeved with the rotating plate 334, and improve the stability of the whole driving structure 33.

[0084] In this way, when it is needed to open the small door cover 32 relative to the small door port 31, the worker clicks start on the operation panel corresponding to the control unit, and then the control unit receives the opening signal sent by the operation panel, and then the push-pull driving device 335 is started first, so that the push-pull driving device 335 controls the small door cover 32 to move away from the corresponding small door port 31, until the small door cover 32 is not in contact with the corresponding small door port 31, and then the control center closes the push-pull driving device 335, and at the same time, the rotating driving device 331 is started, and at this time, the rotating driving device 331 controls the rotating plate 334 and the small door cover 32 located on the rotating plate 334 to move to the outside away from the center of the small door cover 32, so that the corresponding small door port 31 is completely exposed, and then the control unit closes the rotating driving device 331, and then the worker puts the carrier on which the wafer to be processed is placed into the small door port 31 and then places it in the vertical furnace, and then the process is carried out, that is, the specific reaction gas is introduced into the vertical furnace, so as to realize the specific coating, diffusion, oxidation and thin film deposition process on the wafer to be processed.

[0085] When it is needed to close the small door cover 32 relative to the small door opening 31, the operator clicks the closing button on the corresponding operation panel of the control unit, and then the control unit receives the closing signal sent by the operation panel. At this time, the control unit first starts the rotating drive device 331, so that the rotating drive device 331 controls the small door cover 32 on the rotating plate 334 to move to the inner side away from the center of the small door cover 32 for resetting, and then the control center closes the rotating drive device 331, and at the same time, the pushing and pulling drive device 335 is started, so that the pushing and pulling drive device 335 controls the small door cover 32 to move close to the corresponding small door opening 31, until the second protrusion 321 of the small door cover 32 matches the insertion into the annular cavity 312 of the corresponding small door opening 31, so that the small door cover 32 completely covers the corresponding small door opening 31, and then the control unit closes the pushing and pulling drive device 335.

[0086] As shown in FIG. 8 and FIG. 9, the side of the small door cover 32 facing the rotating plate 334 is also provided with a rectangular mounting plate 322, and the pushing and pulling end of the pushing and pulling drive device 335 is connected with the middle part of the mounting plate 322, and the mounting plate 322 is connected with the small door cover 32 through the first guide column 323 around the mounting plate 322. The mounting plate 322 can share part of the weight and load between the small door cover 32 and the pushing and pulling drive device 335, so as to enhance 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 door cover 32 rotates, so as to reduce the damage to the small door cover 32 and the pushing and pulling drive device 335, and prolong the service life thereof; and the mounting plate 322 can be connected with the small door cover 32 through the first guide column 323, so that the relative position between the small door cover 32 and the pushing and pulling drive device 335 can be better adjusted, and the accuracy and stability of the rotation of the small door cover 32 can be ensured. And the mounting plate 322 is also provided with a plurality of lightening holes 324, which can reduce the weight of the mounting plate 322, so that the rotating drive device 331 and the pushing and pulling drive device 335 can better control the movement of the small door cover 32.

[0087] The middle part of the rotating plate 334 is provided with a rectangular mounting area 336, and the middle part of the mounting area 336 is provided with the pushing and pulling drive device 335, and the mounting area 336 is connected with the mounting plate 322 through the second guide column 337 around the mounting area 336. The second guide column 337 in the embodiment is taken as an example of being mounted at the four corners of the mounting area 336. The second guide column 337 can ensure the accurate alignment of the relative position between the mounting plate 322 and the small door cover 32, so that in the process of the rotation of the small door cover 32, the second guide column 337 can guide the mounting plate 322 and the small door cover 32 to move along the predetermined path, so as to prevent the deviation or shift from the correct position, which is helpful to maintain the stability and accuracy of the rotation of the small door cover 32. Embodiment two:

[0088] Please refer to Fig. 11 and Fig. 12, the vertical furnace provided by the 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.

[0089] In the embodiment, the upper furnace cover 2 and the lower furnace door 3 are oppositely arranged, 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 inside the outer furnace tube 13, while the inner furnace tube 14 is coaxially arranged 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 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 jointly form a containing cavity with a concave cross section. The carrier boat bearing device 15 is rotatably arranged in the containing cavity, the carrier boat bearing device 15 is used for bearing the carrier boat 17, the driving device 16 is arranged on the side of the lower furnace door 3 away from the containing cavity, and the driving device 16 is connected with the carrier boat bearing device 15. The driving device 16 is used for driving the carrier boat bearing device 15 to rotate in the containing cavity, so as to drive the carrier boat 17 arranged on the carrier boat bearing device 15 to synchronously rotate, and then make the silicon wafers on the carrier boat 17 be uniformly heated.

[0090] In the embodiment, as shown in Fig. 12 and Fig. 13, the carrier boat bearing device 15 includes a second rotating base 81, a rotating connecting piece 83 and a second bearing piece 82. The second rotating base 81 is arranged in the containing cavity and is sleeved outside 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 piece 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, and the second bearing piece 82 is used for bearing the carrier boat 17. The second bearing piece 82 is provided with a plurality of pairs, each pair of the second bearing piece 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 boat 17 of the embodiment is stacked together without hanging, and the carrier boat 17 on the second rotating base 81 is rotated in the reaction cavity formed by the outer furnace tube 13 and the inner furnace tube 14 by rotating the entire second rotating base 81.

[0091] Specifically, the carrier boat carrying device 15 comprises a second rotating base 81, a second carrier 82 and a rotating connecting piece 83. The rotating connecting piece 83 comprises a fixed connecting part, a heat insulation part and a rotating connecting part, and the heat insulation part is filled with heat insulation material, which can block the heat transfer in the vertical furnace 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 part and the rotating connecting part are arranged on the upper and lower sides of the heat insulation part respectively, the fixed connecting part is connected with the second rotating base 81, and the rotating connecting part is connected with the driving device 16. Among them, the second rotating base 81 is provided with six carrying positions arranged in a circular ring, and each carrying position is provided with two second carriers 82 in a folded state and an unfolded state, and the two second carriers 82 form a pair of second carriers 82. Each second carrier 82 comprises a carrying fixed part 821 and a carrying movable part 822, the carrying fixed part 821 is fixedly arranged on the second rotating base 81, and the carrying movable part 822 is rotatably arranged on the carrying fixed part 821. In any two adjacent pairs of carriers 82, one carrying fixed part 821 belonging to one pair of carriers 82 is connected with one carrying fixed part 821 belonging to another pair of carriers 82. In actual application, in any two adjacent pairs of carriers 82, the two carrying fixed parts 821 connected with each other can be integrally formed. This design can reduce the number of parts and save installation time.

[0092] Taking the rotation angle of the carrying movable part 822 in each carrier 82 as 90 degrees for example, the carrying fixed part 821 is always arranged horizontally, when the second carrier 82 is in the folded state, the carrying movable part 822 is arranged perpendicularly with the carrying fixed part 821, and when the second carrier 82 is in the unfolded state, the carrying movable part 822 is also arranged horizontally. Taking taking and placing a carrier boat 17 for example, if the carrier boat 17 is placed, the two second carriers 82 are switched to the folded state, so that the carrier boat 17 can pass through the carrying position, when the bottom of the carrier boat 17 moves to the carrying position, the two carriers 82 are switched to the unfolded state, so that the carrier boat 17 is placed on the carrier, and subsequently if the carrier boat 17 is taken out, the two carriers 82 are switched to the folded state, so that the carrier boat 17 can pass through the carrying position, thereby realizing the taking and placing of the carrier boat 17.

[0093] In the embodiment, the driving device 16 is arranged on the side of the lower furnace door 3 away from the accommodating cavity, as shown in FIG. 12. The driving device 16 comprises a magnetic fluid sealing assembly 161, a belt 162 and a motor 163. The magnetic fluid sealing assembly 161 comprises a transmission shaft, one end of which is connected with the motor 163 through the belt 162, and the other end of which is connected with the rotating connecting piece 83 in the carrier boat carrying device 15. The carrier boat carrying device 15 is driven to rotate by the motor 163, so as to drive the carrier boat 17 stacked on the carrier boat carrying device 15 to rotate together. It should be noted that the magnetic fluid sealing assembly 161 comprises a fixed seat and a transmission shaft arranged inside the fixed seat, the transmission shaft is provided with two magnetic poles on the outside thereof along the axial direction, a permanent magnet is arranged between the two magnetic poles, and gaps exist between the two magnetic poles and the transmission shaft, and the gaps are filled with magnetic fluid. The magnetic fluid is a colloidal liquid combined with solid and liquid, which is uniformly dispersed into a liquid (carrier liquid) with very low saturated vapor pressure by special treatment of magnetic nanoparticles, and which is neither precipitated nor solidified after mixing with the liquid by a dispersing agent. The magnetic fluid has both fluidity and magnetism. The magnetic fluid vacuum dynamic sealing is realized based on the characteristics. The magnetic fluid sealing assembly 161 is used to fix the magnetic fluid around the shaft by the magnet based on the characteristics of the magnetic fluid, so as to form an "O-shaped sealing ring" of the liquid. The magnetic fluid sealing assembly 161 is connected with the rotatable carrier boat carrying device 15, so that the furnace will not lose pressure and the process gas will not leak out under the premise that the power can be transmitted.

[0094] It should be noted that the specific structures of the upper furnace cover 2, the lower furnace door 3, the outer furnace pipe 13 and the inner furnace pipe 14 in the embodiment are the same as those in the previous embodiment, and will not be described in detail here.

[0095] In the description of the application, it should be noted that when an element is referred to as being "fixed" or "set" on another element, it can be directly on the other element or indirectly on the other element. When an element is referred to as being "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 terms "center", "length", "width", "thickness", "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the purpose of facilitating the description of the application and simplifying the description, and do not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the application. In addition, the terms "first", "second" are only for the purpose of description, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the technical features indicated. Therefore, the features defined with "first", "second" can explicitly or implicitly include one or more of the features. In the description of the application, the meaning of "a plurality of" is two or more, unless otherwise specifically limited.

[0096] The above only describes the preferred embodiments of the application and is not intended to limit the application. Any modifications, equivalent replacements and improvements made within the spirit and principles of the application should be included in the protection scope of the application.

Claims

1. A vertical furnace characterized by, The furnace comprises an upper furnace cover, a lower furnace door, an outer furnace tube and an inner furnace tube, 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 at the inner side of the outer furnace tube, and the end of the inner furnace tube close to the lower furnace door is a closed end and keeps a distance from the lower furnace door; The accommodating cavity is provided with a rotatable carrier boat carrying device for carrying the carrier boat, and the lower furnace door is provided with a driving device for driving the carrier boat carrying device to rotate away from the accommodating cavity.

2. The vertical furnace as claimed in claim 1, wherein, The carrier boat carrying device comprises: a first rotating base between the closed end of the inner furnace tube and the lower furnace door; a rotating shaft connected with the driving device and arranged at one side of the first rotating base; a first carrying member for carrying the carrier boat and arranged at the other side of the first rotating base and sleeved on the outer side of the inner furnace tube.

3. The vertical furnace as claimed in claim 2, wherein The driving device comprises: a motor arranged at the side of the lower furnace door away from the accommodating cavity; a magnetic fluid sealing assembly comprising a transmission shaft, one end of which is connected with the motor through a belt and the other end of which is connected with the rotating shaft.

4. The vertical furnace as claimed in claim 2, wherein The first carrying member comprises a plurality of hanging plates arranged at intervals on the first rotating base, and each hanging plate is provided with a hook hole for the hook on the carrier boat to hang.

5. The vertical furnace as claimed in claim 4, wherein The carrier boat carrying device further comprises a first heat insulation member arranged on the first rotating base and provided with a plurality of limiting holes in the central region for the plurality of hanging plates to pass through.

6. The vertical furnace as claimed in claim 4, wherein The carrier boat carrying device further comprises a second heat insulation member arranged on the first rotating base and provided with a plurality of notches in the edge region for the plurality of hanging plates to pass through.

7. The vertical furnace of claim 1, wherein The carrier boat carrying device comprises: a second rotating base arranged in the accommodating cavity and sleeved on the outer side of the inner furnace tube, the second rotating base being provided with a plurality of carrying positions for the carrier boats to pass through; a rotating connecting member between the closed end of the inner furnace tube and the lower furnace door, connecting the second rotating base with the driving device; a plurality of pairs of second carrying members for carrying the carrier boats, each pair of carrying members being arranged on the second rotating base in a foldable manner at the two sides of a carrying position.

8. The vertical furnace as claimed in claim 7, characterized in that The driving device comprises: a motor arranged at the side of the lower furnace door away from the accommodating cavity; a magnetic fluid sealing assembly comprising a transmission shaft, one end of which is connected with the motor through a belt and the other end of which is connected with the rotating connecting member.

9. The vertical furnace as claimed in claim 7, wherein Each second carrying member in each pair of second carrying members comprises a carrying fixed part fixedly arranged on the second rotating base and a carrying movable part rotatably arranged on the carrying fixed part.

10. The vertical furnace as claimed in claim 1, wherein, The upper end of the upper furnace cover away from the accommodating cavity is upwardly convex to form a spherical protrusion.

11. The vertical furnace as claimed in claim 10, wherein The middle part of the upper furnace cover is provided with a central hole for the inner furnace tube to pass through, the inner side of the upper furnace cover around the central hole is provided with a cavity, and the cavity is provided with a plurality of cavity reinforcing ribs connected between the upper and lower inner walls of the cavity.

12. The vertical furnace of claim 11, wherein The upper furnace cover further comprises a lower layer plate, an outer layer plate and an inner layer plate which cooperate with the upper end face to form the cavity, and the lower layer plate, the outer layer plate and the inner layer plate are all hollow layer plates to form water flow channels or air flow channels.

13. The vertical furnace of claim 11, wherein One end of the inner furnace tube which penetrates the central hole of the upper furnace cover is provided with a connector for hoisting.

14. The vertical furnace of claim 1, wherein The lower furnace door is arranged at the lower end of the outer furnace tube.

15. The vertical furnace of claim 1, wherein The lower furnace door is provided with a small furnace door, and the small furnace door comprises a small furnace door furnace mouth penetrating the lower furnace door and a small furnace door furnace cover corresponding to the small furnace door furnace mouth, and the small furnace door furnace cover is connected with a driving structure for driving the small furnace door furnace cover to open or close relative to the small furnace door furnace mouth.

16. The vertical furnace of claim 1, wherein The carriers are multiple and arranged in a ring shape in the accommodating cavity of the vertical furnace.

17. The vertical furnace of claim 1, wherein The inner side of the inner furnace tube is provided with an inner heating element, and the outer side of the outer furnace tube is provided with an outer heating element, and the inner heating element and the outer heating element are both composed of multiple independent heating sections.

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