Wafer stage and wafer table

Abstract

The utility model discloses a wafer carrier and wafer machine platform, wafer carrier includes: bearing plate and limit fixture, bearing plate is used to bear first crystal boat or second crystal boat, and the size of first crystal boat is not equal with the size of second crystal boat, bearing plate is equipped with first positioning structure, and first crystal boat is equipped with third positioning structure, and first positioning structure is used to and third positioning structure joint, limit fixture includes limit board, and limit board is equipped with second positioning structure, and second positioning structure and first positioning structure joint, and limit board has limit wall, and limit wall and bearing plate constitute limit space, and the partial structure of second crystal boat can be limited in limit space, need not to set up positioning structure to position limit fixture, simple structure, has maximized the first positioning structure of bearing plate.

Description

Technical Field

[0001] This utility model relates to the field of semiconductor manufacturing, and in particular to a wafer carrier and a wafer machine. Background Technology

[0002] In semiconductor manufacturing processes, wafer carriers are used to load and unload wafer boats, and to transport the wafers stored in the wafer boats into or out of the wafer machine. Wafer carriers are typically configured as loading stations or unloading stations.

[0003] Currently, the mainstream wafer size in the market is 12-inch wafers, and the wafer carriers that come with the wafer foundry are also adapted to 12-inch wafer boats. However, in actual production, due to process limitations or other requirements, there are still small-sized wafers that need to be processed, such as 8-inch wafers.

[0004] The wafer stage that comes with the wafer foundry cannot be directly adapted to small-sized wafer boats. A limiting block is needed on the wafer stage to position the small-sized wafer boat. In existing technology, the wafer stage requires a separate fixing structure to secure the limiting block. This additional fixing structure leads to structural complexity and increases the number of process steps. Furthermore, some fixing structures are time-consuming and labor-intensive to install and disassemble; repeated disassembly and reassembly result in severe wear and tear, which can also affect the stability of positioning. Utility Model Content

[0005] One of the objectives of this invention is to provide a wafer stage that at least solves the technical problem of complex structure and process caused by the additional fixing structure for fixing the limiting block in the existing wafer stage.

[0006] To achieve one of the above-mentioned objectives of the utility model, one embodiment of the utility model provides a wafer stage, comprising: a support plate, the support plate being used to support a first wafer boat or a second wafer boat, the size of the first wafer boat being different from the size of the second wafer boat; the support plate being provided with a first positioning structure, the first wafer boat being provided with a third positioning structure, the first positioning structure being used to engage with the third positioning structure; A limiting fixture includes a limiting plate, the limiting plate having a second positioning structure that engages with a first positioning structure, the limiting plate having a limiting wall that forms a limiting space with the bearing plate, and the second crystal boat portion of the structure being confined within the limiting space.

[0007] As a further improvement of one embodiment of the present invention, the bearing plate is provided with a plurality of the first positioning structures, and at least three of the first positioning structures are arranged in a triangular shape.

[0008] As a further improvement of one embodiment of the present invention, the limiting space extends through the limiting fixture, the bottom of the second crystal boat passes through the limiting space and is installed on the support plate, and the limiting plate is located on the outside of the second crystal boat.

[0009] As a further improvement of one embodiment of the present invention, the first crystal boat or the second crystal boat is provided with an opening for the wafer to enter and exit, the limiting plate includes a first segment plate, the first segment plate and the opening are disposed opposite to each other, the limiting wall includes a first limiting wall, the first limiting wall extends from the first segment plate in the direction toward the opening, and the two sides of the first limiting wall are vertical abutment surfaces.

[0010] As a further improvement of one embodiment of the present invention, the limiting plate includes a second segment plate and a third segment plate, the second segment plate and the third segment plate are located on both sides of the first segment plate, and the first segment plate, the second segment plate and the third segment plate surround the limiting space.

[0011] As a further improvement of one embodiment of the present invention, the limiting wall includes a second limiting wall and a third limiting wall. The second limiting wall is disposed at the end of the second segment plate away from the first segment plate and extends in a direction parallel to the window. The third limiting wall is disposed at the end of the third segment plate away from the first segment plate and extends in a direction parallel to the opening. The second limiting wall and the third limiting wall extend toward each other.

[0012] As a further improvement of one embodiment of the present invention, the limiting plate includes a thickened portion, which is disposed on the surface of the limiting plate facing the bearing plate, and the thickened portion is located on both sides of the bearing plate and abuts against the outer side of the bearing plate.

[0013] As a further improvement of one embodiment of the present invention, the limiting fixture includes a handle, which is disposed on the limiting plate. The handle is disposed on the surface of the limiting plate opposite to the bearing plate, and the position of the handle corresponds to that of the thickened part along the height direction of the limiting fixture.

[0014] To achieve one of the above-mentioned objectives of the utility model, one embodiment of the present utility model provides a wafer frame, including: a housing and a wafer stage according to any of the above technical solutions, wherein the housing is provided with a window, the wafer stage is disposed in the window, and the window allows the first wafer boat or the second wafer boat to enter and exit.

[0015] As a further improvement of one embodiment of the present invention, the wafer frame includes a housing and a storage rack. The housing includes a storage area, and the storage rack is used to store the limiting fixture and is disposed within the storage area.

[0016] Compared with the prior art, the present invention provides a wafer stage, including a carrier plate and a limiting fixture. The limiting fixture is used to position the second crystal boat on the carrier plate. The first positioning structure of the carrier plate can directly position the first crystal boat or the limiting fixture. In this way, the limiting fixture is limited to the carrier plate by the first positioning structure, and the wafer stage does not need to have a separate positioning structure, thus maximizing the use of the first positioning structure provided by the carrier plate. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of a wafer stage carrying a second crystal boat in one embodiment of the present invention.

[0018] Figure 2 This is a top view of a wafer stage carrying a second crystal boat in one embodiment of the present invention.

[0019] Figure 3 This is an exploded view of the second crystal boat and the wafer stage in one embodiment of the present invention.

[0020] Figure 4 This is an exploded view of the second crystal boat and wafer stage from another angle in one embodiment of this utility model.

[0021] Figure 5 This is an exploded view of the support plate and the limiting fixture in one embodiment of this utility model.

[0022] Figure 6 This is an exploded view of the bearing plate and the limiting fixture from another angle in one embodiment of this utility model.

[0023] Figure 7 This is a schematic diagram of a wafer processing machine according to one embodiment of the present invention.

[0024] Figure 8 This is a schematic diagram of the wafer machine with its protective cover opened in one embodiment of this utility model.

[0025] Figure 9 This is a schematic diagram of the storage rack and the limiting fixture in one embodiment of this utility model. Detailed Implementation

[0026] The present invention will now be described in detail with reference to the specific embodiments shown in the accompanying drawings. However, these embodiments do not limit the present invention, and any structural, methodological, or functional modifications made by those skilled in the art based on these embodiments are included within the protection scope of the present invention.

[0027] It should be noted that the term "comprising" or any other variation thereof is intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus. Furthermore, the terms "first," "second," "third," "fourth," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0028] The terms “connection,” “connected to,” or any other variations are intended to encompass various relative positions where a connection exists, including both direct and indirect connections. A direct connection can be formed through a pneumatic conduit, while an indirect connection can be formed through devices such as valves or sensors, through pneumatic components such as brake control units, or through any other medium such as air.

[0029] Please see Figure 1 This is a schematic diagram of the structure of a wafer stage 100 provided in an embodiment of the present invention. The wafer stage 100 includes a support plate 10, which is used to support a first wafer boat or a second wafer boat 200. The size of the first wafer boat and the size of the second wafer boat 200 are different. The support plate 10 is provided with a first positioning structure 11, and the first wafer boat is provided with a third positioning structure. The first positioning structure is used to engage with the third positioning structure. The limiting fixture 30 includes a limiting plate 31, which has a second positioning structure 32 that engages with a first positioning structure 11. The limiting plate 31 also has a limiting wall 33, which, together with the carrier plate 10, forms a limiting space 301. The second crystal boat portion of the structure is confined within this limiting space 301, preventing displacement of the second crystal boat relative to the carrier plate 10. Furthermore, the limiting fixture 30 utilizes the first positioning structure 11 to limit the wafer stage 10, eliminating the need for a separate positioning structure on the wafer stage 10 and maximizing the use of the first positioning structure 11 integrated into the carrier plate 10.

[0030] In a specific embodiment, the first crystal boat is a 12-inch crystal boat, and the wafer stage 100 provided with the wafer machine 1 is mainly used to support and position the first crystal boat. The first crystal boat and the wafer stage 100 can be detached and connected to facilitate the loading and unloading of the first crystal boat.

[0031] In a specific embodiment, the first positioning structure 11 and the third positioning structure can be selected as a combination of positioning pins and positioning holes, which is simple in structure and saves time and effort in installation and disassembly.

[0032] The second wafer carrier can be an 8-inch wafer carrier. The existing wafer stage 100 of the wafer processing unit 1 is primarily used to support and position 12-inch wafer carriers. When processing an 8-inch wafer carrier, multiple positioning blocks need to be installed on the wafer stage 100 to position the 8-inch wafer carrier. These positioning blocks are typically connected to the wafer stage 100 using screws. Therefore, switching to an 8-inch wafer carrier is time-consuming and labor-intensive, and repeated disassembly can easily lead to loose connections, affecting positioning stability.

[0033] It can be seen that the first wafer boat is directly positioned on the carrier plate 10 by the cooperation of the third positioning structure and the first positioning structure 11, while the second wafer boat 200 needs to be positioned on the carrier plate 10 by the limiting fixture 30. The first positioning structure 11 is used to directly position the first wafer boat and also to position the limiting fixture 30. After the second positioning structure 32 of the limiting fixture 30 and the first positioning structure 11 are positioned and cooperated, the second wafer boat 200 is then installed on the carrier plate 10 and positioned on the limiting plate 31. The wafer stage 100 does not need to be fixed with screws or other positioning structures to fix the limiting fixture 30. The structure is simple, the installation is convenient, and the cost is saved.

[0034] In a specific embodiment, the first positioning structure 11 and the second positioning structure 32 can be selected as a combination of a positioning post and a positioning hole, which is simple in structure and easy to install and disassemble.

[0035] The support plate 10 is provided with several first positioning structures 11, at least three of which are arranged in a triangular shape. The triangle provides good stability and ensures stable positioning. Combined with... Figure 2-3 As shown, the first positioning structure 11 is a positioning post. A positioning post is symmetrically arranged on both sides of the bearing plate 10 in the left and right directions, and a positioning post is arranged on the front side of the bearing plate 10. The three positioning posts are arranged in an isosceles triangle. In this way, the first positioning structure 11 can achieve both left and right direction positioning and front and back direction positioning for the device to be limited.

[0036] It is understood that both the first and second wafer boats 200 have openings 201, which are used to allow wafers to enter and exit the first and / or second wafer boats 200 respectively. The openings 201 face the window 3 of the wafer rack 1. The wafer rack 1 is equipped with a robotic arm, and the openings 201 face the window 3 so that the robotic arm can pass through the openings 201 and grasp the wafers. The openings 201 are away from the operator, and the front-back direction is perpendicular to the plane where the openings 201 are located. The left-right direction is horizontal and perpendicular to the front-back direction.

[0037] The limiting fixture 30 is provided with a number of second positioning structures 32. The number of second positioning structures 32 is less than that of the first positioning structure 11. When the limiting fixture 30 is installed on the support plate 10, at least one first positioning structure 11 is idle, which reduces measurement accuracy and manufacturing cost.

[0038] Combination Figure 2-3 As shown, the support plate 10 includes three first positioning structures 11 located on the left, right and front sides respectively. The limiting fixture 30 includes two second positioning structures 32 located on the left and right sides respectively. When the limiting fixture 30 is installed on the support plate 10, the front side of the limiting fixture 30 and the first positioning structure 11 on the front side of the support plate 10 are engaged in a spaced-out manner. This means that the limiting fixture 30 will not extend forward to the first positioning structure 11 on the front side. Therefore, the limiting fixture 30 does not have a second positioning structure 21 that engages with the first positioning structure 11 on the front side. The first positioning structure 11 located on the front side is in an idle state that does not require positioning.

[0039] Thus, when designing the limiting fixture 30, only the accuracy of the position of the second positioning structure 32 on the left and right sides needs to be considered, reducing the measurement accuracy of the limiting fixture 30, reducing trial and error costs, and reducing manufacturing costs.

[0040] In other embodiments, the left, right and front sides of the support plate 10 may be provided with a plurality of first positioning structures 11, while the left, right and front sides of the limiting fixture 30 may be provided with only one second positioning structure 32, or the left and right sides of the limiting fixture 30 may be provided with a second positioning structure 32, but the front side of the limiting fixture 30 may not be provided with a second positioning structure 32, so as to ensure better positioning stability and reduce manufacturing costs as much as possible.

[0041] The limiting space 301 passes through the limiting fixture 30, and the bottom of the second crystal boat 200 passes through the limiting space 301 and is installed on the support plate 10. The limiting plate 31 is located outside the second crystal boat 200. In this way, the limiting fixture 30 saves costs and is easy to install and subsequently test.

[0042] The second crystal boat 200 is installed on the support plate 10 through the limiting fixture 30, ensuring that the second crystal boat 200 and the first crystal boat can still share other devices set on the support plate 10, such as the crystal boat detection device; the limiting fixture 30 does not need to bear weight, and the requirements for the material and structure of the limiting fixture 30 are relatively low, reducing manufacturing costs. The second crystal boat 200 is placed on the support plate 10 through the limiting space 301 without being placed on the limiting fixture 30, reducing the space occupied in the vertical direction.

[0043] The limiting fixture 30 is a one-piece integral structure that surrounds the second crystal boat 200. Compared with setting multiple individual limiting blocks, the one-piece integral limiting fixture 30 saves search time, is easier and faster to pick up, and is more convenient to install, saving time and effort.

[0044] The limiting wall 33 is used to abut against the second crystal boat 200 to limit the second crystal boat 200 to the support plate 10. In other embodiments, the limiting wall 33 may be provided with positioning posts / positioning holes, and the second crystal boat 200 may be provided with positioning holes / positioning posts to achieve the limiting function of the limiting wall 33 for the second crystal boat 200.

[0045] The first or second crystal boat 200 is provided with an opening 201 for wafer entry and exit. The limiting plate 31 includes a first section plate 311, which is disposed opposite to the opening 201. The limiting wall 33 includes a first limiting wall 331, which extends from the first section plate 311 toward the opening 201. The two sides of the first limiting wall 331 are vertical abutment surfaces, ensuring that the structure of the second crystal boat 200 opposite to the opening 201 will not shift. The first limiting wall 331 is formed on the front side of the limiting plate 31 to limit the front part of the second crystal boat 200, that is, the part away from the opening 201.

[0046] Combination Figure 3-4 As shown, the first plate 311 is located on the side of the limiting fixture 30 away from the opening 201, which is equivalent to the side facing the operator. The first limiting wall 331 extends rearward from the inner wall of the first plate 311, and both sides of the first limiting wall 331 in the left and right directions are formed as vertical abutment surfaces. In this way, the bottom of the second crystal boat 200 can be abutted by the two sides to the left and right, respectively, thereby limiting the second crystal boat 200 in the left and right directions. The inner wall surface of the first plate 311 is also used to abut the second crystal boat 200, thereby restricting the forward movement of the second crystal boat 200.

[0047] The limiting plate 31 includes a second segment plate 312 and a third segment plate 313. The second segment plate 312 and the third segment plate 313 are located on both sides of the first segment plate 311. The first segment plate 311, the second segment plate 312 and the third segment plate 313 surround the limiting space 301 and are used to limit the second crystal boat 200 in multiple directions to achieve a better limiting effect.

[0048] In one embodiment, the first segment plate 311, the second segment plate 312, and the third segment plate 313 can be straight plates, forming a rectangular limiting space 301; in another embodiment, the first segment plate 311, the second segment plate 312, and the third segment plate 313 can be curved plates, forming an arc-shaped limiting space 301; the design can be selected according to the actual shape of the second crystal boat 200 or other requirements.

[0049] The limiting wall 33 includes a second limiting wall 332 and a third limiting wall 333. The second limiting wall 332 is disposed at the end of the second segment plate 312 away from the first segment plate 311 and extends in a direction parallel to the opening 201. The third limiting wall 333 is disposed at the end of the third segment plate 313 away from the first segment plate 311 and extends in a direction parallel to the opening 201. The second limiting wall 332 and the third limiting wall 333 extend towards each other and together limit the portion of the second crystal boat 200 corresponding to the opening 201 to prevent the portion of the second crystal boat 200 corresponding to the opening 201 from shifting.

[0050] Along a direction parallel to the opening 201, specifically parallel to the plane where the opening 201 is located, the second limiting wall 332 and the third limiting wall 333 are used to jointly limit the rear part of the second crystal boat 200, that is, the part close to the opening 201.

[0051] Combination Figure 5-6 As shown, the second limiting wall 332 is located behind the second crystal boat 200, with the bottom of the second crystal boat 200 abutting against the second limiting wall 332 rearward. The second limiting wall 332 extends in the left-right direction. The third limiting wall 333 is located behind the second crystal boat 200, with the bottom of the second crystal boat 200 abutting against the third limiting wall 333 rearward. The third limiting wall 333 extends towards each other and is symmetrically arranged to ensure the stability of the limiting of the second crystal boat 200.

[0052] Thus, the limiting fixture 30 limits the second crystal boat 200 in the left and right directions through the first limiting wall 331, limits the second crystal boat 200 in the forward direction through the inner wall surface of the first segment plate 311, and limits the second crystal boat 200 in the backward direction through the second limiting wall 332 and the third limiting wall 333, thereby working together to restrict the second crystal boat 200 from moving in the horizontal direction.

[0053] The wafer stage 100 includes a wafer boat detection device 40 disposed on the support plate 10. The wafer boat detection device 40 is exposed in the limiting space 301 to detect whether the first wafer boat or the second wafer boat 200 is in place, facilitating the operation of the operator. The wafer boat detection device 40 includes multiple spaced sensors. Only when all the spaced sensors detect that the first wafer boat or the second wafer boat 200 is in place will the wafer stage 1 determine that the first wafer boat or the second wafer boat 200 is in place, and then control the robotic arm to grasp the wafer.

[0054] The limiting plate 31 includes a thickened portion 34, which is disposed on the surface of the limiting plate 31 facing the support plate 10. The thickened portion 34 is located on both sides of the support plate 10 and abuts against the outer side of the support plate 10 to limit the displacement of the limiting fixture 30 relative to the support plate 10. The limiting is performed by using the outer side of the support plate 10, which has a simple structure and saves costs.

[0055] Combination Figure 4 , 6 As shown, the thickened portions 34 extend rearward from both sides of the first section plate 311 to the second section plate 312 and the third section plate 313, forming a limiting space between the two thickened portions 34. The two sides of the support plate 10 are straight planes extending in the front-back direction, and the inner side of the thickened portions 34 is also a straight plane extending in the front-back direction. The inner sides of the thickened portions 34 at the second section plate 312 and the inner sides of the thickened portions 34 at the third section plate 313 respectively abut against the two sides of the support plate 10, which means that the support plate 10 is located in the limiting space in the left-right direction. In this way, the limiting fixture 30 cannot move in the left-right direction due to the obstruction of the support plate 10, making full use of the structure of the support plate 10 itself and strengthening the positioning stability of the limiting fixture 30.

[0056] The limiting fixture 30 includes a handle 35, which is disposed on the limiting plate 31. The handle 35 is disposed on the surface of the limiting plate 31 away from the bearing plate 10. Along the height direction of the limiting fixture 30, the handle 35 corresponds to the position of the thickened part 34. In this way, the strength of the limiting plate 31 corresponding to the position of the handle 35 can be guaranteed.

[0057] The handle 35 is used by the worker to pick up the limiting fixture 30. The handle 35 is set on both sides of the limiting plate 31, specifically on the upper surface of the second section plate 312 and the upper surface of the third section plate 313. The handle 35 is correspondingly set at the thickened part 34 of the second section plate 312 and the third section plate 313, so there is no need to worry about the strength of the corresponding part of the handle 35.

[0058] This application also protects a wafer frame 1, including the wafer stage 100 and housing 2 as described in any of the above-mentioned technical solutions, combined with... Figure 7-8 As shown, window 3 is formed in the housing 2, and wafer stage 100 is set at the corresponding window 3. Window 3 allows the first wafer boat or the second wafer boat 200 to enter and exit. The wafer stage 100 can switch to carry the first wafer boat or the second wafer boat 200, and can ensure the stability of the positioning of the first wafer boat or the second wafer boat 200.

[0059] Window 3 is used for loading or unloading. Window 3 is opposite to opening 201. Opening 201 and window 3 are used as transport channels for wafers. Wafer machine 1 is provided with loading station 4 and unloading station 5 at the corresponding positions of window 3. Carrier plate 10 is fixed to loading station 4 and unloading station 5. The first wafer boat can be placed directly on carrier plate 10 at the station; or, the limiting fixture 30 can be placed on carrier plate 10 first, and then the second wafer boat 200 can be placed on carrier plate 10 through limiting space 301.

[0060] The wafer frame 1 includes a protective cover 6, which shields the window 3 and covers the wafer stage 100, serving to protect and prevent dust. The protective cover 6 can be opened or closed electrically. When open, the support plate 10 is exposed, allowing the first wafer boat or limiting fixture 30 and the second wafer boat 200 to be taken out or placed in. When closed, the protective cover 6 covers the support plate 10.

[0061] The wafer frame 1 includes a display device 7, which is located in the housing 2 and above the window 3. The display device 7 is communicatively connected to the wafer boat detection device 40. The display device 7 includes indicator lights that correspond one-to-one with the sensors of the wafer boat detection device 40. For example, if the wafer boat detection device 40 includes 6 sensors, the display device 7 includes 6 indicator lights, and the 6 sensors and 6 indicator lights are electrically connected one-to-one. The wafer boat presence status detected by each sensor is displayed through a corresponding indicator light, allowing operators to determine whether the first or second wafer boat 200 is accurately in place.

[0062] The wafer fabrication unit 1 includes a storage rack 9, and the housing 1 includes a storage area 8. The storage rack 9 is used to store the limiting fixture 30, and the storage rack 9 is located within the storage area 8 to ensure the neatness of the wafer fabrication unit 1 and facilitate the retrieval of the limiting fixture 30 when needed. Figure 8-9 As shown, storage area 8 corresponds to the settings panel. Opening the panel will open storage area 8.

[0063] The storage rack 9 includes a support 91 and storage boxes 92. Each storage box 92 is used to house a limiting fixture 30. The first section 311, the second section 312, and the third section 313 of the limiting fixture 30 are straight plates. The limiting fixture 30 is formed into a rectangular plate shape and is placed vertically in the storage box 92. The limiting fixture 30 is placed in the storage box 92 at least at the two corners corresponding to the first section 311. Several storage boxes 92 can be arranged at intervals on the support 91 to simultaneously store multiple limiting fixtures 30. The storage boxes 92 and the support 91 can be optionally detachably connected for easy maintenance and cleaning of the storage boxes 92.

[0064] The advantages of this utility model are as follows: the first positioning structure 11 is used to directly position the first crystal boat and also to position the limiting fixture 30. After the second positioning structure 32 of the limiting fixture 30 is positioned and cooperated with the first positioning structure 11, the second crystal boat 200 is then installed on the carrier plate 10 and limited to the limiting plate 31. The wafer stage 100 does not need to be set with a separate fixing structure to fix the limiting fixture 30. The structure is simple, the installation is convenient, and the cost is saved. The limiting fixture 30 is a one-piece integral fixture. Compared with setting multiple individual limiting blocks, the one-piece integral limiting fixture 30 is easier to pick up and easier to install, saving time and effort.

[0065] This can be formed by referring to any of the technical solutions provided above, and will not be elaborated here.

[0066] It should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This way of describing the specification is only for clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

[0067] The detailed descriptions listed above are merely specific descriptions of feasible implementations of this utility model, and are not intended to limit the scope of protection of this utility model. All equivalent implementations or modifications made without departing from the spirit of this utility model should be included within the scope of protection of this utility model.

Claims

1. A wafer carrier, characterized in that, include: A support plate, which is used to support a first crystal boat or a second crystal boat, wherein the size of the first crystal boat is different from that of the second crystal boat; The carrier plate is provided with a first positioning structure, and the first crystal boat is provided with a third positioning structure. The first positioning structure is used to engage with the third positioning structure. A limiting fixture includes a limiting plate, the limiting plate having a second positioning structure that engages with a first positioning structure, the limiting plate having a limiting wall that forms a limiting space with the bearing plate, and the second crystal boat portion of the structure being confined within the limiting space.

2. The wafer stage according to claim 1, characterized in that, The support plate is provided with a plurality of the first positioning structures, and at least three of the first positioning structures are arranged in a triangular shape.

3. The wafer stage according to claim 1, characterized in that, The limiting space extends through the limiting fixture, the bottom of the second crystal boat passes through the limiting space and is installed on the support plate, and the limiting plate is located on the outside of the second crystal boat.

4. The wafer stage according to claim 1, characterized in that, The first or second crystal boat is provided with an opening for the wafer to enter and exit. The limiting plate includes a first section plate, which is disposed opposite to the opening. The limiting wall includes a first limiting wall, which extends from the first section plate in the direction toward the opening. The two sides of the first limiting wall are vertical abutment surfaces.

5. The wafer stage according to claim 4, characterized in that, The limiting plate includes a second section plate and a third section plate, which are located on both sides of the first section plate. The first section plate, the second section plate, and the third section plate surround the limiting space.

6. The wafer stage according to claim 5, characterized in that, The limiting wall includes a second limiting wall and a third limiting wall. The second limiting wall is disposed at the end of the second segment plate away from the first segment plate and extends in a direction parallel to the opening. The third limiting wall is disposed at the end of the third segment plate away from the first segment plate and extends in a direction parallel to the opening. The second limiting wall and the third limiting wall extend towards each other.

7. The wafer stage according to claim 1, characterized in that, The limiting plate includes a thickened portion, which is disposed on the surface of the limiting plate facing the support plate. The thickened portion is located on both sides of the support plate and abuts against the outer side of the support plate.

8. The wafer stage according to claim 7, characterized in that, The limiting fixture includes a handle, which is disposed on the limiting plate. The handle is located on the surface of the limiting plate opposite to the bearing plate. Along the height direction of the limiting fixture, the handle corresponds to the position of the thickened part.

9. A wafer fabrication machine, characterized in that, include: The housing and the wafer stage according to any one of claims 1-8, wherein the housing is provided with a window, the wafer stage is disposed in the window, and the window allows the first wafer boat or the second wafer boat to enter or exit.

10. The wafer fabrication machine according to claim 9, characterized in that, The wafer frame includes a storage rack, and the housing includes a storage area. The storage rack is used to store the limiting fixture and is disposed within the storage area.

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