Sealing structure and special-shaped quartz tube device

Abstract

The invention discloses a sealing structure and a special-shaped quartz tube device.The sealing structure is applied to sealing of a substrate supporting shaft used by a quartz tube in horizontal type HVPE equipment and comprises an upper static sleeve, a lower static sleeve, a lower static sleeve, a lower static sleeve and a sealing structure, and the upper static sleeve is fixed to the upper end of a bottom hole formed in the preset position of the lower side wall of the horizontal type quartz tube; the lower static sleeve is fixed to the lower end of the bottom hole in an aligned mode, and the lower static sleeve, the upper static sleeve and the bottom hole form a sleeve used for penetrating and lifting of a substrate support lifting rotating shaft; the upper end of the upper movable sleeve is connected to the upper portion of the lifting rotating shaft in a sealed mode through a substrate support or connected to the upper portion of the lifting rotating shaft in a sealed mode, and the upper static sleeve is sleeved with the upper movable sleeve to form an upper labyrinth seal; the lower end of the lower movable sleeve is connected to the lower portion of the lifting rotating shaft in a sealed mode, and the lower static sleeve is sleeved with the lower movable sleeve to form a lower labyrinth seal; according to the sealing structure, the structure is relatively compact, and the reliability is relatively good.

Description

Technical Field

[0001] The present invention relates to a sealing structure for sealing a substrate support shaft used in a quartz tube in a horizontal HVPE device, and also relates to a quartz tube device equipped with the sealing structure, wherein HVPE is the abbreviation of Hydride Vapor Phase Epitaxy, i.e. hydride vapor phase epitaxy. Background Art

[0002] At present, most of the quartz tubes of horizontal HVPE equipment on the market adopt a straight tube structure, and the quartz tube is usually equipped with an air inlet at one end, and the other end is compatible with the air outlet and the substrate holder movement and rotation access port. However, because the reaction area where the substrate holder is located is relatively far away from the end of the quartz tube, the design of the connection structure between the power source for the movement and rotation of the substrate holder and the substrate holder is bound to be more complicated. This is because the design needs to consider factors such as the high temperature resistance of the structure and the prevention of downward deflection of the structure due to excessive length. Therefore, the structure is complex, the cost is high, and assembly is difficult.

[0003] Among them, it is easy to understand that the substrate holder is supported by a rotating shaft, and the rotating shaft needs to be inserted into the quartz tube through the insertion port as mentioned above. Affected by the process temperature in the quartz tube (under 1100°C), the rigidity of the rotating shaft decreases, and the flexural deformation is difficult to control, which makes it difficult for the substrate holder to maintain an ideal posture. Even if a support shaft with a relatively large shear section coefficient is used, such a problem will occur. And when the shear section coefficient of the support shaft is relatively large, its cross-sectional area will also be relatively large, which will inevitably lead to further sealing problems. Summary of the invention

[0004] The object of the present invention is to provide a sealing structure suitable for a horizontal quartz tube with a relatively compact structure and relatively good reliability. The present invention also relates to a special-shaped quartz tube device equipped with the sealing structure.

[0005] According to a first aspect of an embodiment of the present invention, a sealing structure is provided, which is applied to the sealing of a substrate support shaft used in a quartz tube in a horizontal HVPE device, and the sealing structure comprises: The upper static sleeve is fixed to the upper end of the bottom hole opened at a predetermined position on the lower side wall of the horizontal quartz tube; A lower static sleeve is fixed at the lower end of the bottom hole, and the lower static sleeve, the upper static sleeve and the bottom hole form a sleeve for the substrate holder lifting shaft to pass through and lift; The upper movable sleeve has an upper end which is sealed to the upper part of the lifting shaft through a substrate support or an upper end seal, and the upper movable sleeve is sleeved outside the upper static sleeve to form an upper labyrinth seal; The lower moving sleeve has a lower end sealedly connected to the lower part of the lifting shaft, and the lower moving sleeve is sleeved outside the lower static sleeve to form a lower labyrinth seal; Among them, HVPE is the abbreviation of Hydride Vapor Phase Epitaxy, which means hydride vapor phase epitaxy.

[0006] Optionally, the inner and outer walls of the upper static casing and / or the inner wall of the upper movable casing have sealing threads to form an upper thread sealing structure.

[0007] Optionally, the inner surface of the lower movable sleeve is formed with an annular groove or provided with an inner convex ring; A sealing ring is provided and positioned on the annular groove or the upper end surface of the inner convex ring to form a contact type dynamic seal.

[0008] Optionally, if an annular groove is used to position the sealing ring, the annular groove has two paths to respectively position two sealing rings.

[0009] Optionally, a nested tube is provided, which has a compression sleeve between the lower moving sleeve and the lower static sleeve, so as to cooperate with the inner convex ring located at the lower side of the sealing ring from the upper side to clamp and position the sealing ring.

[0010] Optionally, the nested tube further comprises a clamping sleeve which is sleeved outside the lower moving sleeve and connected to the pressing sleeve at the upper end, so as to fix the nested tube on the lower moving sleeve.

[0011] Optionally, the annular cavity between the pressing sleeve and the clamping sleeve is tightly fitted or loosely fitted with the lower movable sleeve; If a loose fit is adopted, a set screw hole is opened on the side of the clamping sleeve to fix the nested tube on the lower moving sleeve by the set screw.

[0012] Optionally, a lower spiral sealing structure is formed between the lower static casing and the lifting shaft.

[0013] According to a second aspect of an embodiment of the present invention, a special-shaped quartz tube device is provided, wherein the quartz tube of the special-shaped quartz tube device is a horizontally arranged quartz tube, and a bottom hole is opened at a predetermined position of the lower tube wall to support the intervention of the lifting shaft of the substrate holder; It is adapted to the bottom hole and is equipped with the sealing structure described in the first aspect of the embodiment of the present invention.

[0014] Optionally, the bottom hole is offset toward a side of the quartz tube furnace cover where the gas outlet is located, and the offset amount is one fifth to one quarter of the total length of the quartz tube.

[0015] In the embodiment of the present invention, the horizontal movable shaft is first changed to a vertical lifting shaft, and there is no problem of flexural deformation caused by the overhang of the horizontal movable shaft, so that the posture of the substrate holder is relatively well maintained. Under the condition that the lifting shaft is inserted from the bottom of the quartz tube, the gas distribution can be carried out on the furnace cover of the quartz tube, reducing the problem of interference with the position and assembly interference of the lifting shaft. Regarding sealing, a step sealing method is adopted. First, an upper static sleeve and a lower static sleeve are constructed at the bottom hole of the quartz tube, and then an upper moving sleeve matched with the upper static sleeve and a lower moving sleeve matched with the lower static sleeve are installed on the lifting shaft. Under this condition, the flow gap has multiple bend effect positions, thereby forming a relatively reliable labyrinth seal, and its overall structure is relatively concise and the reliability is relatively good. In addition, relatively speaking, the rigidity requirements for the vertical lifting shaft are reduced, and the cross-sectional area of ​​the vertical lifting shaft can be relatively small. Under the same conditions, it is relatively easier to achieve sealing. Or under the same sealing conditions, it is easier to achieve a more reliable seal. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 Schematic diagram of the main cross-sectional structure of a special-shaped quartz tube device in one embodiment.

[0017] Figure 2 for Figure 1 Enlarged view of part I.

[0018] Figure 3 for Figure 1 Enlarged view of Part II.

[0019] In the figure: 1. left furnace cover, 2. left sealing ring, 3. quartz tube, 4. substrate holder, 5. furnace chamber, 6. right sealing ring, 7. right furnace cover, 8. lower sealing part, 9. lifting shaft, 10. upper sealing part.

[0020] 81. Support plate, 82. Lower moving casing, 83. Inner convex ring, 84. Sealing ring, 85. Nesting tube, 86. Lower static casing.

[0021] 101. Install the static casing, 102. Install the dynamic casing. DETAILED DESCRIPTION

[0022] To help with the overall understanding, the following first introduces the basic configuration of the quartz tube in the horizontal HVPE equipment. Figure 1 The structure shown, Figure 1 The middle quartz tube 3 is a horizontal cylindrical structure. The known horizontal HVPE equipment is equipped with process gas piping on the two furnace covers and an intervention hole for the substrate support shaft is set on one furnace cover. The substrate support shaft behaves as a horizontal axis, that is, a horizontally moving rotating axis and is easily affected by its own gravity and the gravity of the carried objects and produces deflection, especially when the substrate support shaft overhang exceeds 500mm~1000mm.

[0023] In the embodiment of the present invention, the horizontally arranged substrate holding shaft is changed to a vertically arranged substrate holding shaft, and the state of entering and exiting the furnace chamber 5 becomes lifting. For the convenience of description, the lifting shaft 9 is used below to represent the substrate holding shaft.

[0024] In the embodiments of the present invention, the main components are all rotating bodies, and have relatively typical rotating body characteristics, that is, they have definite axial, circumferential and radial directions.

[0025] Regarding the understanding of the beneficial effects of the embodiments of the present invention, firstly, for the lifting shaft 9, since it is supported vertically and the force-bearing direction is vertical, there is no problem of flexural deformation.

[0026] Furthermore, due to the change in the position of the substrate support shaft, a different sealing method is adopted in the embodiment of the present invention. When the substrate support shaft is a horizontal shaft, it often has to adapt to the length of the quartz tube 3 and has a relatively large stroke. In the embodiment of the present invention, the substrate support shaft is transformed into a vertical support shaft, thereby transforming into Figure 1 The lifting shaft 9 shown in Figure 1 As can be seen, the aspect ratio of the quartz tube 3 is relatively large, and the working stroke of the lifting shaft 9 is relatively small, so a relatively unique sealing structure in the embodiment of the present invention can be used. Obviously, in the embodiment of the present invention, the provided sealing structure is applied to the sealing of the substrate support shaft of the lifting shaft 9 used by the quartz tube 3 in the horizontal HVPE equipment.

[0027] As mentioned above, since the lifting direction of the lifting shaft 9 is the radial direction of the quartz tube 3, its working stroke is much smaller than the traditional substrate support shaft. Therefore, the sealing structure with a specific structure provided by it includes nested cooperation between multiple tube bodies, and forms a labyrinth seal with the help of the multi-bend effect of the flow channel and the boundary friction effect.

[0028] Figure 1 and Figure 2 Four pipe structures can be clearly distinguished, which are the upper movable casing 102, the upper static casing 101, the lower static casing 86, the lower movable casing 82, and an auxiliary pipe, namely the nested pipe 85.

[0029] Correspondingly, a bottom hole is opened at a predetermined position on the bottom wall of the quartz tube 3. The bottom hole is a through hole for the insertion of the lifting shaft 9. The axis of the upper static sleeve 102 and the axis of the lower static sleeve 86 are colinear with the axis of the bottom hole. The three are connected in sequence to form a sleeve.

[0030] As for the sleeve, it can be an integral tube, that is, a tube body is fixed in the bottom hole, or it can be two separate tube bodies, which are respectively welded at the two ends of the bottom hole.

[0031] In view of the static seal between the sleeve and the bottom hole, the sealing is relatively simple, especially the seal can be formed simply by, for example, welding. Even if a detachable structure is adopted, for example, the sleeve is installed on the bottom hole by threaded connection, it should be known that static seal is relatively easy to achieve compared with the difficulty of dynamic seal. In the presence of dynamic seal, the sealing assembly including static seal often does not make special requirements for static seal. Under normal sealing conditions, the sealing ability of static seal is higher than that of dynamic seal.

[0032] The upper static casing 101 is connected to the bottom hole as a whole, and the connection method can be welding as mentioned above, or it can be threaded connection. When threaded connection is adopted, the bottom hole adopts a threaded hole.

[0033] In addition, the casing can be a reducer as a whole, the corresponding part of the upper static casing 101 is relatively small, and the threaded part of the casing corresponds to the bottom hole part, and can be fixed on the bottom hole by threaded connection.

[0034] The welding type is adopted, and grooves are opened at both ends of the bottom hole for connection with girth welds. Obviously, the upper static casing 101 is located at the upper end of the bottom hole.

[0035] In this way, the upper static sleeve 101 and the lower static sleeve 86 are used to construct the static part of the sealing structure based on the fixed connection with the quartz tube 3.

[0036] The upper movable sleeve 102 and the lower movable sleeve 82 are two sleeves that move with the lifting shaft 9, wherein the upper end of the upper movable sleeve 102 is sealed or connected to the upper part of the lifting shaft 9 through the substrate holder 4. Figure 1 In the illustrated structure, the upper movable sleeve 102 and the substrate holder 4 are an integral structure, and the two can be welded into an integral structure. The upper movable sleeve 102 is a cylindrical structure, and its upper end can be directly sealed with the substrate holder 4, or can be sealed by connecting with the lifting shaft 9. The upper end of the upper movable sleeve 102 is sealed as a static sealing structure, which is generally directly sealed based on, for example, welding, and will not be described in detail here.

[0037] Furthermore, the upper movable sleeve 102 forms an upper barrel body with the barrel mouth at the bottom based on the sealing between the upper movable sleeve 102 and the substrate holder 4, and is sleeved on the upper static sleeve 101 from top to bottom, and a first matching gap exists between the two, and a second matching gap is formed between the upper static sleeve 101 and the lifting shaft 9, and there are two elbows between the two matching gaps, thereby forming an upper labyrinth seal, that is, Figure 1 The upper sealing portion 10 is shown in FIG.

[0038] Figure 3 The lower movable sleeve 82 is directly and sealedly connected to the lower part of the lifting shaft 9. The connection between the two can be welded or threaded. Figure 2The upper sealing portion 10 shown in FIG. is different in that Figure 3 The lower sealing portion 8 shown in the figure is located outside the furnace chamber 5 and is less affected by the process temperature in the furnace chamber 5, so a rubber sealing ring with relatively poor temperature resistance can be used for sealing. However, in the embodiment of the present invention, a labyrinth seal is preferably used.

[0039] Specifically, due to the connection between the lower end of the lower moving sleeve 82 and the lifting shaft 9, a lower barrel structure can be formed, which is sleeved from bottom to top on the outer side of the lower static sleeve 86 to form a lower labyrinth seal. Similar to the sealing part, based on this structure, a third matching gap, a fourth matching gap, and two elbows are formed in sequence.

[0040] In summary, the upper sealing portion 10 and the lower sealing portion 8 may have at least four matching gaps and four elbows, thereby forming a relatively reliable labyrinth sealing structure.

[0041] In addition, the labyrinth seal structure is a dynamic seal structure and a non-contact seal. Therefore, the above four fitting gaps have a certain size, which only needs to avoid motion interference, such as 0.2~1mm. If the fitting gap is less than 0.5mm, a lubricant can be applied, such as graphite suitable for high temperature conditions.

[0042] In some embodiments, as a further preferred structure of the labyrinth seal structure, the inner and outer walls of the upper static casing 101 and / or the inner wall of the upper movable casing 102 have sealing threads to form an upper thread sealing structure. Correspondingly, the upper sealing thread sealing structure may have one or two to adapt to the aforementioned first fitting clearance and second fitting clearance.

[0043] Similarly, for the third fitting gap and the fourth fitting gap without a sealing member, a threaded sealing structure can also be adopted, which will not be described in detail here.

[0044] It should also be noted that, for the lifting shaft 9, there is heat conduction, and a seal is used for sealing, and it is arranged between the lower static sleeve 86 and the lower dynamic sleeve 82 as much as possible to reduce the thermal impact of heat conduction.

[0045] Figure 3 In the embodiment, the inner surface of the lower movable sleeve 82 is provided with an inner convex ring 83, and an annular groove may also be provided. When the annular groove is provided, the general application of using the annular groove to position the sealing ring 84 is satisfied, and no further description is given here.

[0046] An inner convex ring 83 is provided, and the upper surface of the inner convex ring 83 can be used as a bearing surface. The sealing ring 84 is sleeved on the lower static sleeve 86 and is supported and positioned by the upper end surface of the inner convex ring 83, thereby forming a contact type dynamic seal. The contact type dynamic seal, in conjunction with the upper labyrinth sealing structure and the lower labyrinth sealing structure, can fully meet the sealing capacity required for the lifting shaft 9 to intervene in the furnace chamber 5.

[0047] In order to improve the sealing capability, if an annular groove is used to position the sealing ring 84 , the annular groove has two paths to respectively position the two sealing rings 84 .

[0048] For applications with an inner convex ring 83, in order to improve the relative stability of the positioning position of the sealing ring 84 and avoid damage to the sealing ring 84 due to additional torque generated by rolling, a nested tube 85 is provided. The nested tube 85 has a compression sleeve between the lower moving sleeve 82 and the lower static sleeve 86, so as to cooperate with the inner convex ring 83 located on the lower side of the sealing ring 84 from the upper side to clamp and position the sealing ring 84.

[0049] In addition, if Figure 3 As shown, the nested tube 85 also includes a clamping sleeve that is sleeved outside the lower moving sleeve 82 and connected to the pressing sleeve at the upper end to fix the nested tube on the lower moving sleeve 82.

[0050] Furthermore, the annular cavity between the pressing sleeve and the clamping sleeve is tight fit or loose fit with the lower movable sleeve 82; as mechanical common sense, loose fit refers specifically to clearance fit, and tight fit includes transition fit and interference fit, among which interference fit can reach the connection level, so interference fit is also called interference connection.

[0051] If a loose fit is adopted, a set screw hole is opened on the side of the clamping sleeve to fix the nesting tube 85 on the lower moving sleeve 82 by the set screw.

[0052] exist Figure 1 In the illustrated structure, the bottom hole is offset toward the side of the quartz tube furnace cover where the gas outlet is located, and the offset amount is one fifth to one quarter of the total length of the quartz tube 3.

[0053] Figure 1 In the figure, the left furnace cover 1 is the exhaust furnace cover, and the right furnace cover 7 is the intake furnace cover. It should be known that for the conventional horizontal quartz tube 3, the length of the reaction zone is about 500 mm, and only a small part of the reaction zone has the most stable temperature field, and the rest belongs to a relatively stable area. Under the condition of adopting the vertical setting of the lifting shaft 9, the size requirement of the reaction zone is relatively small, and the reaction can be carried out in a smaller reaction zone, and the area with the most stable temperature field can be selected. In other words, the section of the quartz tube 3 with the most stable temperature field in the aforementioned 500 mm can be selected as the installation position of the lifting shaft 9, and the aforementioned offset can be selected.

[0054] The offset mentioned is obviously a relative position relative to the lifting shaft 9 being located exactly in the middle of the quartz tube 3.

Claims

1. A sealing structure, applied to the sealing of a substrate support shaft used in a quartz tube in a horizontal HVPE device, characterized in that: The sealing structure comprises: The upper static sleeve is fixed to the upper end of the bottom hole opened at a predetermined position on the lower side wall of the horizontal quartz tube; A lower static sleeve is fixed at the lower end of the bottom hole, and the lower static sleeve, the upper static sleeve and the bottom hole form a sleeve for the substrate holder lifting shaft to pass through and lift; The upper movable sleeve has an upper end which is sealed to the upper part of the lifting shaft through a substrate support or an upper end seal, and the upper movable sleeve is sleeved outside the upper static sleeve to form an upper labyrinth seal; The lower moving sleeve has a lower end sealedly connected to the lower part of the lifting shaft, and the lower moving sleeve is sleeved outside the lower static sleeve to form a lower labyrinth seal; Among them, HVPE is the abbreviation of Hydride Vapor Phase Epitaxy, which means hydride vapor phase epitaxy.

2. The sealing structure according to claim 1, characterized in that: The inner and outer walls of the upper static casing and / or the inner wall of the upper movable casing are provided with sealing threads to form an upper thread sealing structure.

3. The sealing structure according to claim 1, characterized in that: The inner surface of the lower movable sleeve is formed with an annular groove or provided with an inner convex ring; A sealing ring is provided and positioned on the annular groove or the upper end surface of the inner convex ring to form a contact type dynamic seal.

4. The sealing structure according to claim 3, characterized in that: If an annular groove is used to position the sealing ring, the annular groove has two paths to respectively position the two sealing rings.

5. The sealing structure according to claim 3, characterized in that: A nested tube is provided, which has a compression sleeve between a lower moving sleeve and a lower static sleeve, so as to cooperate with the inner convex ring located at the lower side of the sealing ring from the upper side to clamp and position the sealing ring.

6. The sealing structure according to claim 5, characterized in that: The nested tube also includes a clamping sleeve body which is sleeved outside the lower moving sleeve and connected to the pressing sleeve at the upper end so as to fix the nested tube on the lower moving sleeve.

7. The sealing structure according to claim 6, characterized in that: The annular cavity between the pressing sleeve and the clamping sleeve and the lower movable sleeve are tightly fitted or loosely fitted; If a loose fit is adopted, a set screw hole is opened on the side of the clamping sleeve to fix the nested tube on the lower moving sleeve by the set screw.

8. The sealing structure according to any one of claims 5 to 7, characterized in that: A lower spiral sealing structure is formed between the lower static casing and the lifting shaft.

9. A special-shaped quartz tube device, characterized in that: The quartz tube equipped with the heterogeneous quartz tube device is a horizontally arranged quartz tube, and a bottom hole is opened at a predetermined position on the lower tube wall to support the intervention of the lifting shaft of the substrate holder; Adapted to the bottom hole, equipped with the sealing structure described in any one of claims 1 to 8.

10. The heterogeneous quartz tube device according to claim 9, characterized in that: The bottom hole is offset toward one side of the quartz tube furnace cover where the gas outlet is located, and the offset amount is one fifth to one quarter of the total length of the quartz tube.

Images