Guiding device for supporting shaft of crucible holder

Abstract

The invention discloses a crucible holder supporting shaft guiding device, the basic structure of the crucible holder supporting shaft guiding device comprises a disc body arranged in a preset cavity, the disc body is provided with a center hole used as a seat hole, and the disc body is fixedly arranged or vertically movably arranged in the corresponding cavity; the rotating seat is mounted in the seat hole through a bearing, and the rotating seat is provided with a matching hole; the supporting shaft is guided in the matching hole or is fixedly connected with the matching hole; and one or two pairs of rollers are arranged on the disc body, and the two inner rollers are symmetrical about the axis of the supporting shaft so as to guide the supporting shaft from the two opposite sides. According to the crucible holder supporting shaft guiding device, the supporting stability is relatively good.

Description

Technical Field

[0001] The invention relates to a crucible support shaft guide device. Background Art

[0002] Due to the demanding growth environment of semiconductor crystals, the reaction chamber needs to be sealed and face a given process temperature. In addition, the temperature environment of the reaction area is relatively complex. The axial length of the reaction area in the reaction chamber is generally 500~1000mm. The support shaft used to support the growth crucible is required to have a corresponding working stroke, and the adapted crucible is often required to have a rotation function according to the process requirements. Under this condition, it is necessary to ensure that the support shaft has sufficient rigidity to ensure that the lifting and rotating processes of the crucible support are relatively smooth.

[0003] It should be known that the stiffness of the support shaft is necessarily negatively correlated with the process temperature of the working environment, that is, the higher the process temperature, the worse the stiffness. It is also negatively correlated with the overhang distance relative to the support point, that is, the longer the overhang distance, the worse the stiffness of the support shaft. As mentioned above, first of all, in order to meet the lifting and lowering of the crucible, the support shaft should obviously have a relatively large length to meet the lifting and lowering stroke of the crucible, and at the same time, it should be able to adapt to the problem of maintaining stiffness under the process temperature conditions of the corresponding process.

[0004] For long-stroke rods, reinforcing ribs are generally set on the side to strengthen them, but this structure affects the seal and is difficult to use in the application environment of the present invention. In some implementations, nested multi-stage rod assemblies can also be used, but the drive of the multi-stage cylinder is generally difficult to adapt to relatively high ambient temperatures. For example, the process temperature of the reaction zone is 600°C, which has exceeded the flash point of most hydraulic oils. If gas is used as the working medium, the pipeline configuration of the multi-stage cylinder will also become very difficult. The relevant pipeline needs to follow at least the second-stage cylinder body, which is difficult to work under high process temperature conditions. Summary of the invention

[0005] The object of the present invention is to provide a crucible support shaft guide device with relatively good supporting stability.

[0006] According to an embodiment of the present invention, a crucible support shaft guide device is provided, the basic structure of which includes: A disc body is arranged in a predetermined cavity, the disc body has a central hole used as a seat hole, and the disc body is fixedly arranged in the corresponding cavity or movably arranged up and down; A swivel seat is installed in the seat hole through a bearing, and the swivel seat has a matching hole; A support shaft, guided in the matching hole or fixedly connected to the matching hole; The rollers are mounted on the disc body and are provided in one or two pairs. The two rollers in a pair are symmetrical about the axis of the support shaft so as to guide the support shaft from opposite sides.

[0007] Optionally, if the disc is fixedly arranged, the disc is installed between the reaction zone and the lower cover plate of the chamber; If the disc is movably arranged up and down in the chamber, a guide rod is provided on the side of the disc away from the reaction zone; Correspondingly, a guide hole for guiding the guide rod and a through hole for supporting the shaft to intervene in the chamber are opened on the lower cover plate of the cavity; The guide rod is connected to the support shaft outside the chamber.

[0008] Optionally, if the disc is movably arranged up and down in the chamber, a guide rail is provided on the cavity wall of the chamber to form a guide rail pair with the disc.

[0009] Optionally, a bearing for guiding the support shaft is installed in the through hole; A linear bearing is arranged in the guide hole.

[0010] Optionally, the component used to connect the guide rod and the support shaft is a plate-type lifting seat; A bellows is arranged between the lower cover plate and the lifting seat to provide dynamic sealing for the guide rod and the supporting shaft exposed outside the chamber.

[0011] Optionally, the bellows includes a second bellows corresponding to the guide rod one by one, the upper end of the second bellows is connected to the flange between the upper cover plate, the lower end is connected to the flange between the lifting seat, and the second bellows is coaxial with the guide rod; The support shaft is equipped with a first bellows coaxial with the support shaft. The upper end of the first bellows is connected to the flange between the upper cover plate, and the lower end is connected to the flange between the lifting seat.

[0012] Optionally, a roller track is provided on the support shaft at a position aligned with the roller; The roller is a groove wheel, and the corresponding raceway is a ridge that matches with the wheel groove of the groove wheel.

[0013] Optionally, the swivel seat has a journal for mounting a bearing, and a stopper penetrating a center hole from the bottom; The limit head is provided with a limit component to lock the swivel seat on the disk body in the axial direction.

[0014] Optionally, if the disc is fixedly arranged in the chamber, the furnace tube constituting the chamber comprises an upper furnace tube and a lower furnace tube, and the upper furnace tube is connected to the lower furnace tube by a flange; The disc body forms a flange disc and is clamped between the upper furnace tube and the lower furnace tube.

[0015] Optionally, the furnace tube below the reaction zone is recorded as a lifting furnace tube, and the position of the disc in the lifting furnace tube is 0.3~0.45h away from the lower end surface of the furnace tube, where h is the length of the lifting furnace tube.

[0016] In an embodiment of the present invention, a component for providing auxiliary support to the support shaft is provided in a predetermined chamber, and the component includes a disk body, which can be fixedly arranged in the chamber or can be moved up and down in the chamber. It should be known that the reaction zone in the chamber is often a part of the axial cavity section in the chamber, and there is often a certain distance between the part of the axial cavity section and the lower cover plate of the chamber. The disk body is arranged between the reaction zone and the lower cover plate. The thermal impact of this part of the area is mainly thermal radiation, and the thermal convection is basically suppressed here. In other words, it belongs to the area with relatively low temperature in the chamber. A rotating seat is installed on the disk body, and the rotating seat is installed on the disk body through a bearing. A matching hole is opened on the rotating seat. The matching hole connects the support shafts circumferentially, and can be connected or guided in the axial direction, thereby providing auxiliary support to the support shaft in the chamber to improve the static stiffness and dynamic stiffness of the support shaft, which is conducive to the support shaft providing relatively stable support for the crucible support. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a schematic diagram of the main cross-sectional structure of the crucible support shaft guide device in one embodiment.

[0018] Figure 2 It is a schematic diagram of the main cross-sectional structure of a crucible support shaft guide device according to another embodiment.

[0019] Figure 3 Schematic diagram of the sealing structure of the crucible support shaft guide device in another embodiment.

[0020] In the figure: 1. lower cover plate, 2. first linear bearing, 3. lower furnace tube, 4. lower flange, 5. plate, 6. upper flange, 7. screw, 8. upper furnace tube, 9. reaction zone, 10. crucible support, 11. support shaft, 12. roller, 13. swivel seat, 14. rotary bearing, 15. retaining ring, 16. furnace tube, 17. guide rail, 18. second linear bearing, 19. guide rod, 20. lifting seat, 21. motor, 22. lifting frame, 23. push rod, 24. second bellows, 25. first bellows. DETAILED DESCRIPTION

[0021] from Figure 1 As can be seen in FIG. 1 , the position of the reaction zone 9 in the semiconductor process equipment is relatively high, and there is a relatively long distance between the reaction zone 9 and the lower cover plate 1 . Figure 1 The structure shown in the figure can be a whole, and the other components except the lower cover plate 1 are fed into the furnace cavity.

[0022] In addition, the furnace cavity may have an inner tube and an outer tube. Figure 1The upper furnace tube 8 and the lower furnace tube 3 shown in the figure are mainly used to construct a part of the structure of the inner furnace tube, which can be taken out as a whole, and the crucible is placed on the crucible holder 10, or the substrate is taken in and placed in the crucible that has been placed in place.

[0023] It should be known that the typical characteristic of thermal convection is that if the heating device is located at the lower side, the hot gas will move upward due to the lower heat and the upper cold and the relatively small density of the hot gas, while the cold gas will move downward due to the relatively large density of the cold gas. This is the property of thermal convection. In the field of semiconductor technology, heating is often performed in the middle and upper part of the furnace cavity, resulting in a phenomenon in which the temperature in the middle and upper part is high and the temperature in the lower part is low. Therefore, thermal convection is suppressed, so that the temperature in the lower part of the furnace cavity is relatively low, which is conducive to sealing and ensuring that the support shaft 11 works relatively stably at this location.

[0024] Regardless of whether it is constructed as a vacuum chamber, the chamber of the current semiconductor process equipment is generally a rotating body structure, and has a certain axial direction. Under the condition that the axial direction is determined, its basic reference system is determined. In addition, the crucible support shaft guide device based on the embodiment of the present invention is suitable for vertical semiconductor process equipment, and has a certain up and down.

[0025] It should be noted that even a vacuum chamber does not mean that there is a vacuum environment inside it. In more applications, the chamber is often evacuated first and then the reaction gas or protective gas is introduced. Therefore, there is often still a certain amount of gas in the chamber, which is irrelevant to the concept of the present invention and will not be described in detail here. However, even if there is reaction gas, the heat convection is suppressed in the lower part of the chamber, and the thermal impact on the support shaft 11 is relatively weak.

[0026] In addition, except for applications with relatively high vacuum degree, the vacuum chamber does not have high requirements for sealing. At the same time, it should be known that for vacuum, the lowest vacuum degree is only negative one atmosphere relative to the relative pressure. Compared with the industrial pressure of dozens or hundreds of atmospheres (for example, low pressure refers to 0.7MPa~1.0MPa, medium pressure refers to 1.MPa0~10MPa, high pressure refers to 10~100MPa, and 1MPa is generally equivalent to 10 atmospheres), the sealing ability that can be achieved in industry is already very strong, and I will not go into details here.

[0027] In an embodiment of the present invention, a crucible support shaft guide device is provided, wherein the base of the part for providing auxiliary support is Figure 1 and Figure 2 The disk body 5 shown in the example, Figure 1 In the illustrated structure, the disk body 5 is fixedly arranged. Under this condition, although the support shaft 11 still has a long overhang, it becomes a double-point support because of the additional support point, which can also effectively improve its overall static stiffness and dynamic stiffness.

[0028] And in Figure 2In the illustrated structure, the disc body 5 follows the movement of the support shaft 11 , so that the overhang of the support shaft 11 relative to the disc body 5 becomes a fixed value, which is more conducive to ensuring the static stiffness and dynamic stiffness of the support shaft 11 .

[0029] The disk body 5 is located in a chamber, which is a chamber of the corresponding semiconductor process equipment, and from a positional point of view, it must be located below the reaction zone 9, because the disk body 5 is used as an auxiliary support for the support shaft 11, and must be located in the area where the support shaft 11 is located. The support shaft 11 only needs to partially intervene in the reaction zone 9 in the working state, and the part that intervenes in the reaction zone 9 is relatively short compared to its overall stroke, and the auxiliary support of the support shaft 11 by the disk body 5 does not need to be supported at the end of the support shaft 11, so that the disk body 5 must be located below the reaction zone 9, and the lower area is relatively less affected by the heat of the reaction zone.

[0030] The disc body 5 is provided with a first central hole serving as a seat hole, and the seat hole is mainly used for installing a bearing so that the support shaft 11 can rotate.

[0031] Correspondingly, another rotating seat 13 is provided, and the rotating seat 13 is Figure 1 The rotating bearing 14 shown in FIG. 1 is mounted on the disk body 5, and the rotating seat 13 provides a structure of the degree of freedom of rotation of the supporting shaft 11. Specifically, on the one hand, the rotating seat 13 is provided by Figure 1 and Figure 2 The rotary bearing 14 shown in the figure is installed on the disk body 5 and has the freedom of rotation. Furthermore, the swivel seat 13 has a second center hole used as a matching hole. The support shaft 11 is slidably matched with the second center hole to form a circumferential connection, thereby leaving a connection mode with freedom in the axial direction.

[0032] The matching relationship between the matching hole and the support shaft 11 is a clearance fit, and there is no need to use a medium seal or a contact seal. Even if the sealing performance is relatively poor, as mentioned above, due to the suppression of heat convection, even if there is a certain matching clearance, for example, the matching clearance of the φ30 (mm) shaft hole under the IT7 level matching accuracy is 0.01~0.044mm, which is very small and sufficient to produce a good seal. At this time, the first-level seal is formed, and the first-level seal still has a relatively good seal under the condition of dynamic sealing. At the same time, due to the matching between the swivel seat 13 and the seat hole, there will be a second leakage point. Relatively speaking, the bearing and the swivel seat 13 are generally interference fits, which belong to the static connection level of sealing. The leakage point is mainly the sealing ability of the rotating bearing 14 itself. Under this condition, the rotating bearing 14 can use a bearing with a cover to reduce the leakage ability at the rotating bearing 14.

[0033] In addition, in some embodiments, the disk body 5 and the support shaft 11 are raised and lowered synchronously. Under this condition, there is no relative movement between the matching hole and the support shaft 11, so they can be statically connected to each other without considering the sealing performance between the disk body 5 and the support shaft 11.

[0034] Regarding the support shaft 11, as mentioned above, the main consideration in the embodiment of the present invention is the guidance of the support shaft 11. In other words, the support shaft 11 must belong to a known implementation object for ensuring its technical performance, and as for its structure or construction, there is at least a relatively mature implementation in the prior art.

[0035] In addition, in the embodiment of the present invention, under the condition that the support shaft 11 has auxiliary support, it can have other structures different from the prior art, such as Figure 2 The support shaft 11 shown in the figure has a raceway structure that can cooperate with the roller 12, but it should be known that even if it is a traditional cylindrical shaft, the roller groove of the roller 12 can be adapted to a roller groove with an arc-shaped cross-section according to the outer profile of the cylindrical shaft.

[0036] Since the raceway can be a structure with a roller groove that adapts to the roller 12, or it can be a structure in which the roller 12 adapts to the contour surface of the support shaft 11 as mentioned above, relatively speaking, when the roller groove of the roller 12 adapts to the contour surface of the support shaft 11, the support shaft 11 can use a cylindrical structure, which is conducive to other structural configurations, such as the cooperation between the support shaft 11 and the lower cover plate 1 (there is axial movement and circumferential movement between them).

[0037] If a ridge-shaped raceway is provided separately, for example, the raceway can also constitute a structure similar to a sliding key, that is, the circumferential connection between the swivel seat 13 and the support shaft 11 does not need to be provided with a sliding key separately, but the raceway can be directly used to constitute the sliding key, so that the raceway is reused here.

[0038] The rollers 12 are arranged on the rotating seat 13 in an axially symmetrical manner, and the rollers 12 are arranged in one pair or two pairs. Overall, the rollers 12 are evenly arranged corresponding to the circumference of the support shaft 11. The paired arrangement is conducive to making the force center fall on the axis of the support shaft 11.

[0039] Regarding the roller 12, it is obviously suitable for the embodiment in which the matching hole constitutes a guide hole, that is, the support shaft 11 is guided in the matching hole. Under this condition, the roller 12 is provided to assist in guiding to avoid or reduce the possible jamming caused by the shaft-hole matching.

[0040] The roller 12 can be fixedly arranged on the rotating seat 13 through a roller seat. In addition, in some embodiments, there can be a degree of freedom of swinging between the roller seat of the roller 12 and the rotating seat 13, and the angular range is not greater than 15 degrees. Specifically, the roller 12 can be installed on the rotating seat 13 through a swing frame, and the back side of the swing frame, that is, the side away from the support shaft 11, is provided with a hard limit, such as a baffle or a block. The swing frame is hingedly mounted on the rotating seat 13, and a torsion spring is used, for example, to provide a force for the roller 12 to press the support shaft 11. Under this condition, hard jamming that may occur when the roller seat is fixed can be avoided, and the guide of the roller seat to the support shaft 11 can be relatively smooth.

[0041] exist Figure 1 The illustrated structure is an example of a fixed arrangement of the disk 5. In the figure, the disk 5 is installed between the reaction zone 9 and the lower cover plate 1 of the chamber; as mentioned above, the lower cover plate 1 also constitutes the lower end cover of the process equipment. In other words, the part above the upper surface of the lower cover plate 1 is placed in the process chamber, but not all areas of the process chamber can meet the process requirements, and it is necessary to select a predetermined section from it as the reaction zone 9. The reaction zone 9 is the area in the chamber that meets the process requirements. And as mentioned above, the temperature in the reaction zone 9 is higher than the temperature of the area below it. Obviously, the farther away from the reaction zone 9, the weaker the thermal impact on the part including the rotating seat 13.

[0042] exist Figure 1 In the illustrated structure, the disk 5 is located between the reaction zone 9 and the lower cover plate 1. Figure 1 The chamber located below the reaction zone 9 in the illustrated structure is called a lifting furnace tube. The "lifting" in the lifting furnace tube is only used to distinguish the furnace tube by name, and does not mean that the furnace tube itself can be lifted or lowered.

[0043] Furthermore, regarding the position of the disc 5 when it is fixed in the lifting furnace tube, it can be seen from the figure that the disc 5 is centered and offset downward in the lifting furnace tube, but the offset is not large. Generally, based on the lower end surface of the lifting furnace tube (which is also the lower end surface of the overall furnace tube), the distance between the disc 5 and the lower end surface is 0.3~0.45h, where h is the length of the lifting furnace tube.

[0044] The fixing method of the disc body 5 in the lifting furnace tube can be a non-detachable connection, which has good reliability and does not need to consider the sealing problem.

[0045] exist Figure 1 In the illustrated structure, the disc 5 is connected in a detachable manner in the lifting furnace pipe, and the lifting furnace pipe adopts an assembled pipe structure. Figure 1 In the embodiment, the furnace tube part of the lifting furnace tube comprises an upper furnace tube 8 and a lower furnace tube 3, and the upper furnace tube 8 and the lower furnace tube 3 are connected by a flange; the plate body 5 constitutes a flange plate and is clamped between the upper furnace tube 8 and the lower furnace tube 3. The overall maintainability can be improved based on the detachable connection mode.

[0046] Figure 2 and Figure 3 These are examples of adaptability when the disc 5 is movably arranged up and down in the chamber. Under this condition, if Figure 2 and Figure 3 As shown, a guide rod 19 is provided on the side of the tray 5 facing away from the reaction zone 9 .

[0047] It should be noted that, since heat convection is suppressed, the temperature inside the lifting furnace tube is relatively low. At the same time, due to the shielding of the disk 5, heat radiation can also be effectively suppressed, so that the space below the disk 5 away from the reaction zone 9 is less affected by heat. Therefore, when the guide rod 19 is configured, a guide sleeve can also be adapted, so that lubrication can be carried out by, for example, solid lubricants. Lubrication at a relatively low temperature is completely possible. For example, the operating temperature of graphite lubricants can reach 450°C. Even if the operating temperature of the reaction zone 9 is very high, such as 1200°C, because heat convection is suppressed and heat radiation is shielded by the disk 5, the use conditions of at least solid lubricants can still be met at the lower cover plate 1.

[0048] Correspondingly, a guide hole for guiding the guide rod 19 is opened on the lower cover plate 1 of the cavity. The guide hole can be inlaid with a copper sleeve, which is a common material for constructing sliding bearings. For example, the working temperature of the bronze sleeve can reach 400℃~500℃, which can fully adapt to the use conditions of the lower cover plate 1.

[0049] In some implementations, the lower cover plate 1 may be provided with a water cooling structure, in which case other types of lubricants may also be used, such as lubricating oil or lubricating grease.

[0050] In addition to using a bushing such as a copper sleeve to construct a sliding bearing, a linear bearing can also be directly used to guide the guide rod 19. Accordingly, the linear bearing is installed in the guide hole.

[0051] In addition to the guide hole, a through hole is also required to be adapted for the support shaft 11 to pass through from the chamber or to allow the support shaft 11 to enter the chamber from outside the chamber through the through hole.

[0052] Furthermore, the guide rod 19 and the support shaft 11 are connected outside the chamber, so that the overall structure has better reliability. Figure 2 and Figure 3 In the illustrated structure, the guide rod 19 and the support shaft 11 are connected by a lifting seat 20, that is, at least the guide rod is fixed on the lifting seat 20, and is used to drive the support shaft 11 to rotate. Figure 2 The motor 21 shown in FIG. 1 can be installed on the upper surface of the lifting base 20 , or can be installed on the lower surface of the lifting base 20 .

[0053] Furthermore, in Figure 2In the illustrated structure, if the disk body 5 is movably arranged up and down in the chamber, a guide rail is provided on the chamber wall to form a guide rail pair with the disk body 5 .

[0054] In order to further improve the static seal under dynamic sealing conditions, the dynamic seal is converted into a static seal through a bellows. Taking the guide rod 19 as an example, Figure 3 In the process, there is a clearance between the guide rod 19 and the second linear bearing 18, and the sealing form between the two is a dynamic seal. Figure 3 In the figure, a second bellows 24 is provided between the lower cover plate 1 and the lifting seat 20. The second bellows 24 is sleeved outside the guide rod 19 and is coaxial with the guide rod 19. At the same time, the upper flange of the second bellows 24 is connected to the lower cover plate 1 to form an upper flange to form a static seal, and the lower flange is connected to the flange of the lifting seat 20 to form a static seal, thereby forming a relatively reliable seal.

[0055] The dynamic seal of the support shaft 11 is converted into a static seal, and similarly, it will not be described in detail here.

[0056] It should be noted that Figure 3 Several relatively small bellows are used for switching between dynamic sealing and static sealing, but a relatively large bellows can be shared to accommodate the guide rod 19 and the part of the support shaft 11 located outside the chamber.

[0057] In addition, Figure 1 and Figure 2 In the illustrated structure, the swivel seat 13 has a journal for mounting a bearing and a stopper with a center hole extending from the bottom; a stopper is mounted on the stopper to axially lock the swivel seat 13 on the disk body 5. The stopper ring 15 used in the figure is generally an elastic stopper ring, which is relatively convenient to use.

Claims

1. A crucible support shaft guide device, characterized in that: include: A disc body is arranged in a predetermined cavity, the disc body has a central hole used as a seat hole, and the disc body is fixedly arranged in the corresponding cavity or movably arranged up and down; A swivel seat is installed in the seat hole through a bearing, and the swivel seat has a matching hole; A support shaft, guided in the matching hole or fixedly connected to the matching hole; The rollers are mounted on the disc body and are provided in one or two pairs. The two rollers in a pair are symmetrical about the axis of the support shaft so as to guide the support shaft from opposite sides.

2. The crucible support shaft guide device according to claim 1, characterized in that: If the disk is fixed, the disk is installed between the reaction zone and the lower cover of the chamber; If the disc is movably arranged up and down in the chamber, a guide rod is provided on the side of the disc away from the reaction zone; Correspondingly, a guide hole for guiding the guide rod and a through hole for supporting the shaft to intervene in the chamber are opened on the lower cover plate of the cavity; The guide rod is connected to the support shaft outside the chamber.

3. The crucible support shaft guide device according to claim 2, characterized in that: If the disc is movably arranged up and down in the chamber, a guide rail is provided on the cavity wall of the chamber to form a guide rail pair with the disc.

4. The crucible support shaft guide device according to claim 2, characterized in that: A bearing for guiding the support shaft is installed in the through hole; A linear bearing is arranged in the guide hole.

5. The crucible support shaft guide device according to claim 2, characterized in that: The component used to connect the guide rod and the support shaft is a plate-type lifting seat; A bellows is arranged between the lower cover plate and the lifting seat to provide dynamic sealing for the guide rod and the supporting shaft exposed outside the chamber.

6. The crucible support shaft guide device according to claim 5, characterized in that: The bellows includes a second bellows corresponding to the guide rod one by one, the upper end of the second bellows is connected to the flange between the upper cover plate, the lower end is connected to the flange between the lifting seat, and the second bellows and the guide rod are coaxial; The support shaft is equipped with a first bellows coaxial with the support shaft. The upper end of the first bellows is connected to the flange between the upper cover plate, and the lower end is connected to the flange between the lifting seat.

7. The crucible support shaft guide device according to claim 1, characterized in that: A roller track is provided on the support shaft at a position aligned with the roller; The roller is a groove wheel, and the corresponding raceway is a ridge that matches with the wheel groove of the groove wheel.

8. The crucible support shaft guide device according to claim 1 or 7, characterized in that: The swivel seat has a journal for mounting a bearing, and a stopper extending through a center hole from the bottom side; The limit head is provided with a limit component to lock the swivel seat on the disk body in the axial direction.

9. The crucible support shaft guide device according to claim 1, characterized in that: If the disc is fixedly arranged in the chamber, the furnace tube constituting the chamber comprises an upper furnace tube and a lower furnace tube, and the upper furnace tube and the lower furnace tube are connected by a flange; The disc body forms a flange disc and is clamped between the upper furnace tube and the lower furnace tube.

10. The crucible support shaft guide device according to claim 9, characterized in that: The furnace tube below the reaction zone is denoted as the lifting furnace tube, and the position of the disc in the lifting furnace tube is 0.3-0.45h away from the lower end surface of the furnace tube, where h is the length of the lifting furnace tube.

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