A graphite boat and a combined graphite boat sheet thereof

Abstract

The application discloses a graphite boat and a combined graphite boat sheet, and belongs to the technical field of semiconductor production, which comprises a plurality of graphite boat sheets combined together, clamping end plates arranged on the two sides of the graphite boat sheets, and bearing sockets for mounting semiconductor wafers arranged on the graphite boat sheets, wherein the side walls of the bearing sockets are connected with hoop rings through spacing optimization pads, the hoop rings are used for blocking the movement of the semiconductor wafers, and the inner diameters of the spacing optimization pads are matched with the outer diameters of the semiconductor wafers. The application adjusts the distance inside the graphite boat, keeps the outside unchanged, keeps the physical distance of adjacent graphite separators consistent, makes the overall external size of the graphite boat and the sheet spacing completely match the original automatic sheet inserting machine, avoids a series of problems such as production management confusion and equipment re-adaptation caused by the change of the overall size, and makes the marginal cost of technology upgrading extremely low and the landing feasibility extremely high.

Description

Technical Field

[0001] This invention relates to the field of semiconductor manufacturing technology, and in particular to a graphite boat and its composite graphite boat sheet. Background Technology

[0002] In the manufacturing of semiconductor devices (such as solar cells), differences in the deposition rate of wafers on a graphite boat can lead to discrepancies in the device's photoelectric performance parameters, severely restricting chip yield and conversion efficiency. Specifically, the semiconductor wafer film thickness (usually visually reflected as "film color") on the outer layers of the graphite boat is significantly lighter, while the semiconductor wafer film thickness in the central region is much darker. This uneven film thickness distribution severely restricts the product's appearance consistency, yield, and final photoelectric conversion efficiency.

[0003] According to the circuit equivalent model, in a parallel circuit, the voltage remains constant, the current through the capacitor is inversely proportional to the distance d between its plates, and the deposition rate of the semiconductor wafer is directly proportional to this current. Therefore, the final deposition rate is inversely proportional to the plate spacing. Based on this principle, existing technologies have proposed increasing the distance between the two sides of the graphite boat to compensate for the insufficient deposition rate in the edge region. However, this approach has significant drawbacks: First, changing the overall spacing between the wafers would alter the shape and size of the graphite boat, making it incompatible with the existing automated wafer insertion machines on the production line, resulting in high modification costs. Second, increasing the spacing would disrupt the original positioning stability of the semiconductor wafers, making them prone to displacement or falling during loading, unloading, and processing, seriously affecting production safety and efficiency. Finally, such modifications would also complicate production management and hinder standardized operations.

[0004] Therefore, how to effectively control the equivalent plate spacing at different positions inside the graphite boat through innovative design without changing the overall external dimensions of the graphite boat and its compatibility with automated production, thereby fundamentally solving the problem of film thickness uniformity, has become a technical bottleneck that the industry urgently needs to overcome. Summary of the Invention

[0005] The purpose of this invention is to solve the problems existing in the prior art, and to propose a graphite boat and its combined graphite boat sheet.

[0006] To achieve the above objectives, the present invention adopts the following technical solution: A composite graphite boat sheet includes multiple graphite boat sheets assembled together. Clamping end plates are provided on both sides of each graphite boat sheet. The clamping end plates are connected to the multiple graphite boat sheets by fasteners to maintain a consistent spacing between all graphite boat sheets. Each graphite boat sheet has a carrier slot for mounting a semiconductor wafer. The sidewall of the carrier slot is connected to a clamping ring through a spacing optimization pad. The clamping ring is used to prevent the semiconductor wafer from moving. The inner diameter of the spacing optimization pad is adapted to the outer diameter of the semiconductor wafer. Both ends of the graphite boat are provided with fluid guides, and the ends of the fluid guides are detachably connected to electrode terminals; The thickness difference between adjacent spacing optimization pads gradually increases from the middle to both sides.

[0007] As a preferred embodiment, the graphite boat has multiple fastening holes arranged in an alternating vertical pattern. The fastener includes a connecting rod that passes through the multiple fastening holes and graphite spacers on the graphite boat in sequence and is connected to the clamping end plate at the other end.

[0008] A graphite boat for carrying a combined graphite boat sheet includes a graphite boat body mounted on a wafer attitude conversion system. The graphite boat body includes a combined base that is assembled and mounted with the wafer attitude conversion system. The combined base is assembled and connected to the graphite boat sheet through multiple support brackets. The wafer attitude conversion system includes a lower assembly stage, a flip seat is provided above the assembly stage, a stabilizing groove is provided on the flip seat, and a rotation adjustment component is provided inside the assembly stage to control the rotation of the flip seat.

[0009] As a preferred embodiment, the support bracket is provided with a support seat, and the support seat has a groove corresponding to the graphite boat sheet on its upper part. Both ends of the support seat are provided with stabilizing pressure plates.

[0010] As a preferred embodiment, a stabilizing limiting arc groove is provided above the assembly platform, and a limiting arc-shaped component located within the stabilizing limiting arc groove is provided at the bottom of the flipping seat.

[0011] As a preferred embodiment, the rotating adjustment component includes an arc-shaped flipping tooth groove formed on the limiting arc-shaped component located in the middle, and the assembly table is provided with a flipping gear controlled by a drive source. The flipping gear is located in the stable limiting arc groove and meshes with the arc-shaped flipping tooth groove.

[0012] As a preferred embodiment, the stabilizing groove is provided with a locking seat for restricting the movement of the combined base.

[0013] Compared with the prior art, the beneficial effects of the present invention are as follows: 1. Based on the equivalent model of the coating circuit, this invention creatively proposes to regulate the current density distribution by adjusting the actual effective spacing between adjacent semiconductor wafers, rather than the physical spacing of the graphite boat. By setting up spacing optimization pads with thickness gradually increasing from the middle to both sides, the equivalent spacing between edge semiconductor wafers is reduced, and the current is increased, thereby precisely improving the deposition rate in the edge region. This effectively solves the problem of film color (film thickness) being darker in the middle and lighter at both sides, significantly improving the uniformity and consistency of semiconductor wafer coating, thereby directly improving the product appearance quality, battery conversion efficiency, and overall yield.

[0014] 2. This invention adjusts the spacing inside the graphite boat while keeping the outside unchanged, maintaining a consistent physical distance between adjacent graphite spacers. This ensures that the overall external dimensions and inter-sheet spacing of the graphite boat are perfectly matched with the existing automated wafer inserter. This eliminates the need to modify or replace the expensive automated wafer inserter and avoids a series of problems such as production management chaos and equipment re-adaptation caused by changes in overall dimensions. As a result, the marginal cost of the technology upgrade is extremely low, and the feasibility of implementation is extremely high.

[0015] 3. During the insertion process of this invention, the semiconductor wafer is first horizontally inserted into the carrier slot, and then the graphite boat is turned from horizontal to vertical by the flipping table. During this process, the semiconductor wafer automatically slides into the stable slot composed of the spacing optimization pad and the clamping ring under the action of gravity, and is firmly limited by the clamping ring, realizing the secondary positioning and locking of the semiconductor wafer. From the mechanical structure, the risk of semiconductor wafer falling off (dropping) during movement, transportation and process is eliminated, ensuring the continuity and stability of production. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the structure of a combined graphite boat sheet proposed in this invention; Figure 2 This is a schematic diagram of the assembly state of a combined graphite boat sheet proposed in this invention; Figure 3 This is a schematic diagram of the cross-sectional structure of the graphite boat sheet in the graphite boat and its combined graphite boat sheet proposed in this invention. Figure 4 This is a schematic diagram of the combined structure of a combined graphite boat sheet proposed in this invention; Figure 5 This is a schematic diagram of the assembly state structure of a graphite boat and its combined graphite boat wafer wafer attitude conversion system proposed in this invention. Figure 6 This is a schematic diagram of the combined structure of a graphite boat and its combined graphite boat wafer wafer attitude conversion system proposed in this invention; Figure 7 This is a schematic diagram of the structure of the support bracket and the graphite boat sheet in the assembled state of a graphite boat and its combined graphite boat sheet proposed in this invention; Figure 8 This is a schematic diagram of the structure of the support bracket in a graphite boat and its combined graphite boat sheet proposed in this invention.

[0017] In the diagram: 1. Graphite boat leaf; 2. Clamping end plate; 3. Bearing bayonet; 4. Spacing optimization pad; 5. Clamping ring; 6. Fluid guide; 7. Electrode end; 8. Connecting rod; 9. Graphite spacer; 10. Fastening hole; 11. Combined base; 12. Assembly table; 13. Flip seat; 14. Bearing support; 15. Slot; 16. Stabilizing pressure plate; 17. Stabilizing limiting arc groove; 18. Limiting arc-shaped component; 19. Arc-shaped flip tooth groove; 20. Flip gear; 21. Locking seat. Detailed Implementation

[0018] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0019] In the description of this invention, it should be noted that the terms "upper," "lower," "inner," "outer," "top / bottom," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0020] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installed," "equipped with," "sleeved / connected," "connected," etc., should be interpreted broadly. For example, "connection" can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium; it can be a connection within two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0021] Example, refer to Figures 1 to 8A graphite boat and its combined graphite boat sheet, comprising multiple graphite boat sheets 1 assembled together, wherein there are 14 graphite boat sheets in this embodiment. Clamping end plates 2 are provided on both sides of the graphite boat sheets 1. The clamping end plates 2 are connected to the multiple graphite boat sheets 1 by fasteners. The fasteners are used to keep the spacing of all graphite boat sheets 1 consistent. The graphite boat sheets 1 are provided with a carrier bayonet 3 for mounting semiconductor wafers. The side wall of the carrier bayonet 3 is connected to a clamping ring 5 through a spacing optimization pad 4. The clamping ring 5 is used to prevent the semiconductor wafer from moving. The inner diameter of the spacing optimization pad 4 is adapted to the outer diameter of the semiconductor wafer. The thickness difference between adjacent spacing optimization pads 4 gradually increases from the middle to both sides, that is, the thickness difference between the two sides of the spacing optimization pad 4 is the largest, while the middle spacing optimization pad 4 is in the middle of the thickness, so that the adjacent semiconductor wafer in the middle is exactly the same as the traditional distance. With this setting, the distance between the adjacent semiconductor wafer in the middle and the adjacent semiconductor wafers on both sides is constantly increasing. That is, by changing the spacing of the graphite boat, the coating efficiency on both sides can be improved, thereby ensuring that the film color (film thickness) on the finished semiconductor wafer is uniform and consistent. The thickness difference of adjacent spacing optimization pad 4 can be more clearly defined from the formula: d1-d2=∆d, ∆d is the thickness difference, which gradually increases from the middle to both sides. d1 and d2 are the thicknesses of two adjacent spacing optimization pads 4. d1 and d2 are the thicknesses of two adjacent spacing optimization pads, and along the graphite boat sheet arrangement direction, ∆d gradually increases from the middle to both ends.

[0022] Both ends of the graphite boat page 1 are provided with guide fluids 6. The ends of the guide fluids 6 are detachably connected to electrode terminals 7. The cooperation between the guide fluids 6 and the electrode terminals 7 is the key interface for connecting the graphite boat to an external power source.

[0023] Furthermore, the graphite boat 1 has multiple fastening holes 10 arranged in an alternating pattern. The fastener includes a connecting rod 8, which passes through the multiple fastening holes 10 and graphite spacers 9 on the graphite boat 1 in sequence, and is connected to the clamping end plate 2 at the other end.

[0024] To ensure consistency in production management and eliminate the need to replace the automatic chip inserter, the distance between adjacent graphite spacers 9 in this solution is consistent, meaning it is compatible with traditional automatic chip inserters and does not require redesign.

[0025] The graphite boat includes a graphite boat body mounted on a wafer attitude conversion system. The graphite boat body includes a combined base 11 that is assembled and installed with the wafer attitude conversion system. The combined base 11 is assembled and connected to the graphite boat sheet through multiple support brackets. The support bracket is provided with multiple support seats 14, and multiple slots 15 corresponding to the graphite boat sheets are opened on the upper part of the support seats 14. Both ends of the support seats 14 are provided with stabilizing pressure plates 16.

[0026] Multiple stabilizing and limiting arc grooves 17 are provided above the assembly table 12, and a limiting arc-shaped component 18 located in the stabilizing and limiting arc grooves 17 is provided at the bottom of the flipping seat 13.

[0027] The wafer attitude conversion system includes an assembly stage 12 below and a flip base 13 above the assembly stage 12. The flip base 13 has a stabilizing groove and a retaining seat 21 for restricting the movement of the assembly base 11. When the graphite boat is loaded with semiconductor wafers, the graphite boat is placed in the stabilizing groove on the assembly stage 12. The stabilizing groove ensures that the graphite boat is in a stable state when it is rotated. The assembly table 12 is equipped with a rotation adjustment component that controls the rotation of the flip seat 13. The rotation adjustment component includes an arc-shaped flip tooth groove 19 opened on the limiting arc-shaped component 18 located in the middle. The assembly table 12 is equipped with a flip gear 20 controlled by a drive source. The drive source is a servo motor and its reducer, which can realize the slow flipping of the flip seat 13. The flip gear 20 is located in the stable limiting arc groove 17 and meshes with the arc-shaped flip tooth groove 19.

[0028] In this invention, when loading semiconductor wafers, the graphite boat carrying the semiconductor wafers is placed in a stable slot on the flipping seat 13. An automated wafer inserter automatically inserts the semiconductor wafers between adjacent graphite boat pages 1 and gradually moves them into the carrier slot 3 that is compatible with the semiconductor wafers (this is the function of the automated wafer inserter). At this time, the automated wafer inserter completes the installation of the semiconductor wafers, but the installation between the semiconductor wafers and the graphite boats is not yet complete. The installation of the graphite boat and semiconductor wafers continues: After the automatic wafer inserter is removed, the rotation of the flip gear 20 located in the assembly table 12 drives the flip base 13, which is connected to the flip gear 20 through the arc-shaped flip groove 19, to rotate. This causes the graphite boat, which contains the semiconductor wafers, to gradually rotate from a horizontal state to a vertical state. During this process, the semiconductor wafers in the support bayonet 3 will gradually change from a vertical position to a horizontal position during the rotation, and will automatically move from the support bayonet 3 to the horizontal position under the influence of their own gravity. Within the spacing optimization pad 4, and ultimately fixed in position by the clamping ring 5, the semiconductor wafer's thickness difference gradually increases from the middle to both sides. Therefore, the semiconductor wafer's movement distance within the spacing optimization pad 4 is also greater from one side to the other. This ensures that the spacing between adjacent semiconductor wafers in the middle gradually decreases compared to the spacing between adjacent semiconductor wafers on both sides. By changing the spacing of the graphite boat, the coating efficiency on both sides can be improved. Furthermore, the spacing optimization pad 4 and clamping ring 5 effectively prevent the semiconductor wafer from falling off, thus ensuring coating quality.

[0029] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A composite graphite boat sheet, characterized in that, The system includes multiple graphite boats (1) assembled together. Each graphite boat (1) has clamping end plates (2) on both sides. The clamping end plates (2) are connected to the multiple graphite boats (1) by fasteners. The fasteners are used to keep the spacing of all graphite boats (1) consistent. Each graphite boat (1) has a carrier slot (3) for mounting semiconductor wafers. The side wall of the carrier slot (3) is connected to a clamping ring (5) through a spacing optimization pad (4). The clamping ring (5) is used to prevent the semiconductor wafer from moving. The inner diameter of the spacing optimization pad (4) is adapted to the outer diameter of the semiconductor wafer. Both ends of the graphite boat (1) are provided with guide fluids (6), and the ends of the guide fluids (6) are detachably connected to electrode terminals (7). The thickness difference between adjacent spacing optimization pads (4) gradually increases from the middle to both sides.

2. The composite graphite boat sheet according to claim 1, characterized in that, The graphite boat (1) has multiple fastening holes (10) arranged in an alternating pattern. The fastener includes a connecting rod (8), which passes through the fastening holes (10) and graphite spacers (9) on the graphite boat (1) in sequence, and is connected to the clamping end plate (2) at the other end.

3. A graphite boat for carrying the combined graphite boat sheet according to any one of claims 1-2, characterized in that, The system includes a graphite boat mounted on a wafer attitude conversion system. The graphite boat includes a combined base (11) that is assembled and mounted with the wafer attitude conversion system. The combined base (11) is assembled and connected to the graphite boat through a support bracket. The wafer attitude conversion system includes an assembly platform (12) below, a flip seat (13) is provided above the assembly platform (12), a stabilizing groove is provided on the flip seat (13), and a rotation adjustment component is provided inside the assembly platform (12) to control the rotation of the flip seat (13).

4. A graphite boat according to claim 3, characterized in that, The support bracket is provided with a support seat (14), and a groove (15) corresponding to the graphite boat sheet is opened on the upper part of the support seat (14). Both ends of the support seat (14) are provided with stabilizing pressure plates (16).

5. A graphite boat according to claim 4, characterized in that, The assembly table (12) is provided with a stable limiting arc groove (17) above it, and the bottom of the flipping seat (13) is provided with a limiting arc part (18) located in the stable limiting arc groove (17).

6. A graphite boat according to claim 5, characterized in that, The rotating adjustment component includes an arc-shaped flip tooth groove (19) opened on the limiting arc-shaped component (18) located in the middle. The assembly table (12) is provided with a flip gear (20) controlled by a drive source. The flip gear (20) is located in the stable limiting arc groove (17) and meshes with the arc-shaped flip tooth groove (19).

7. A graphite boat according to claim 6, characterized in that, The stabilizing groove is provided with a locking seat (21) for restricting the movement of the combined base (11).

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