Graphite boat for coating silicon-based wafers

Abstract

The application relates to a graphite boat for coating a silicon-based wafer, which comprises: graphite boat pieces, a plurality of the graphite boat pieces are arranged in an array; a ceramic sleeve arranged between adjacent graphite boat pieces for separating the adjacent graphite boat pieces; and a ceramic rod arranged through the ceramic sleeve for connecting the graphite boat pieces into a whole. The graphite boat piece comprises a boat piece body, an electrode connecting part and an insert piece detachably connected with the boat piece body, the electrode connecting part is connected with the positive and negative poles of an external power supply respectively; a plurality of bearing parts are arranged on the boat piece body for loading a silicon-based wafer, and the insert piece is detachably connected with the bearing parts. The application can effectively solve the problem of wafer backside coating, improve the stability and efficiency of the coating process, and meet the demand of modern microelectronic industry for high-quality film preparation.

Description

Technical Field

[0001] This invention relates to the field of semiconductor fabrication technology, and in particular to a graphite boat for silicon-based wafer coating. Background Technology

[0002] In semiconductor manufacturing, silicon-based wafer deposition is a key process, widely used in integrated circuits, microelectromechanical systems (MEMS), and optoelectronic devices. Deposition processes typically employ physical vapor deposition (PVD) or chemical vapor deposition (CVD) techniques to form high-quality thin films on the wafer surface, achieving functions such as conductivity, insulation, protection, or optical properties. The graphite boat is a crucial component supporting the wafer, and its structure directly affects the deposition quality. However, despite the maturity of existing silicon-based wafer deposition technologies, current deposition equipment and graphite boats face the following challenges in practical applications: The electric field distribution of traditional graphite boats may be uneven, leading to uneven material deposition during the coating process and affecting the performance and reliability of the thin film. Slight wafer movement during coating can affect the uniformity of the film layer and even cause defects. Existing fixing methods struggle to balance precise positioning with ease of operation. Graphite boats are prone to localized overheating or uneven heat conduction at high temperatures, affecting film quality and potentially shortening equipment lifespan. Traditional graphite boats have complex structures, making cleaning difficult and leading to the accumulation of coating residues, which affects the quality of subsequent coatings. Gaps at the wafer-boat contact surface allow plasma or gas to bypass the deposition back side, causing plating swirl problems.

[0003] Therefore, existing technologies need to be improved. Summary of the Invention

[0004] In the prior art, existing coating equipment and graphite boats have problems such as wafer fixation stability and coating around the wafer in practical applications. Therefore, the present invention provides a graphite boat for silicon-based wafer coating to solve the above problems.

[0005] To achieve the above objectives, the present invention provides a graphite boat for silicon-based wafer coating, comprising: Graphite boat sheets, and an array of multiple graphite boat sheets are arranged; A ceramic sleeve is disposed between adjacent graphite boat sheets to separate adjacent graphite boat sheets; A ceramic rod, passing through the ceramic sleeve, is used to connect the graphite boat sheets into a whole; The graphite boat includes a boat body, an electrode connection portion, and inserts detachably connected to the boat body. The electrode connection portion is connected to the positive and negative terminals of an external power supply, respectively. The boat body is provided with multiple support portions for loading silicon-based wafers, and the inserts are detachably connected to the support portions.

[0006] In one implementation, the insert is disposed at the top of the boat body. The insert includes an integral insert body portion and an insert carrier portion. The thickness of the insert body portion is the same as the thickness of the boat body, and the thickness of the insert carrier portion is the same as the thickness of the carrier portion. The insert carrier portion and the carrier portion are used together to load the silicon-based wafer.

[0007] In one implementation, the insert further includes engaging portions disposed on both sides of the insert body portion, the boat body includes a slot corresponding to the engaging portion, and the thickness of the engaging portion is less than the thickness of the insert body portion.

[0008] In one implementation, the support portion is located at the middle of the boat body, and a plurality of the support positions are evenly arranged along the length direction of the boat body.

[0009] In one implementation, the supporting portion is a circular groove structure with the same or different diameters.

[0010] In one implementation, the graphite boat further includes process points for precise positioning and fixing of the silicon-based wafer, and the boat body is provided with positioning holes corresponding to the process points.

[0011] In one implementation, each of the supporting parts includes three locking holes, including a support locking hole located below the supporting part and side locking holes located on both sides of the supporting part.

[0012] In one implementation, graphite nuts are provided at both ends of the ceramic rod, and the graphite nuts are used to lock and fix the plurality of graphite boat pieces.

[0013] In one implementation, the graphite boat includes a positive graphite boat for connection to a positive electrode and a negative graphite boat for connection to a negative electrode; in the positive graphite boat, the electrode connecting block is a positive electrode connecting plate, and two positive electrode connecting plates are respectively disposed on both sides of the boat body and located at the upper part of the boat body; in the negative graphite boat, the electrode connecting plate is a negative electrode connecting plate, and two negative electrode connecting plates are disposed on both sides of the boat body and located at the lower part of the boat body.

[0014] In one implementation, the graphite boat further includes spacers for assisting in connecting graphite boat sheets with the same electrode, and the spacers are connected and fixed to each other by the ceramic rod and the graphite nut.

[0015] Beneficial Effects: The graphite boat for silicon-based wafer coating provided by this invention, through a detachable structure of inserts and the boat body, allows the inserts to support the wafer from the back and seal the edges of the graphite boat, forming a sealed cavity, effectively solving the problem of back-side coating. Simultaneously, ceramic sleeves and rods are used to insulate the graphite boat, ensuring electric field control and equipment safety during the coating process. The graphite boat for silicon-based wafer coating provided by this invention has a modular and easy-to-assemble overall structure, is suitable for large-scale parallel wafer coating processes, and has good process compatibility and ease of maintenance. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the overall structure of the graphite boat for silicon-based wafer coating provided by the present invention; Figure 2 yes Figure 1 The image shown is a partial enlarged view of a graphite boat used for silicon-based wafer coating. Figure 3 yes Figure 1 The diagram shows a front view of a graphite boat used for silicon-based wafer coating. Figure 4 yes Figure 4 The diagram shows an exploded view of a graphite boat used for silicon-based wafer coating. Figure 5 yes Figure 4 The image shown is a partial magnified view of a silicon-based wafer coating. Figure 6 yes Figure 4 The diagram shows the overall structure of the insert. The labels in the diagram are illustrated as follows: 10. Graphite boat sheet; 101. Positive electrode graphite boat sheet; 102. Negative electrode graphite boat sheet; 11. Boat sheet body; 111. Supporting part; 112. Slot; 113. Positioning hole; 12. Electrode connection part; 121. Positive electrode connection plate; 121. Negative electrode connection plate; 13. Insert; 131. Insert body part; 132. Insert supporting part; 133. Engaging part; 20. Ceramic sleeve; 30. Ceramic rod; 40. Process point; 50. Graphite nut; 60. Spacer.

[0017] The realization of the objective, functional features and advantages of the present invention will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0018] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention. Furthermore, the terms "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., described below refer to specific features, structures, materials, or characteristics described in connection with that embodiment or example, which are included in at least one embodiment or example of the invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Moreover, the technical features involved in the various embodiments of the invention can be combined with each other as long as they do not conflict with each other.

[0019] See also Figures 1-5 , Figure 1 This is a schematic diagram of the overall structure of the graphite boat for silicon-based wafer coating provided by the present invention. Figure 2 yes Figure 1 The image shown is a partial enlarged view of a graphite boat used for silicon-based wafer coating. Figure 3 yes Figure 1 The image shown is a front view of a graphite boat used for silicon-based wafer coating. Figure 4 yes Figure 1 The diagram shown is an exploded view of a graphite boat used for silicon-based wafer deposition. Figure 5 yes Figure 4 The image shown is a magnified view of a portion used for silicon-based wafer coating.

[0020] This invention provides a graphite boat for silicon-based wafer coating, comprising: Graphite boat sheet 10, and an array of multiple graphite boat sheets 10 are arranged; A ceramic sleeve 20 is disposed between adjacent graphite boat sheets 10 to separate adjacent graphite boat sheets 10. A ceramic rod 30 is disposed through the ceramic sleeve 20 and is used to connect the graphite boat sheet 10 into a whole; The graphite boat 10 includes a boat body 11, an electrode connection part 12, and a plug 13 detachably connected to the boat body 11. The electrode connection part 12 is connected to the positive and negative terminals of an external power supply. The boat body 11 is provided with a plurality of support parts 111 for loading silicon-based wafers, and the plug 13 is detachably connected to the support parts 111.

[0021] For details, please refer to Figure 6 , Figure 6 yes Figure 4The diagram shows the overall structure of the insert. The insert 13 is disposed at the top of the boat body 11. The insert 13 includes an integral insert body portion 131 and an insert support portion 132. The thickness of the insert body portion 131 is the same as the thickness of the boat body 11. The thickness of the insert support portion 132 is the same as the thickness of the support portion 111. The insert support portion 132 and the support portion 111 are used together to load the silicon-based wafer.

[0022] By ensuring that the thickness of the insert body 131 matches the thickness of the boat body 11, a smooth surface can be ensured. The insert support 132 allows for precise mating between the insert 13 and the support 111, achieving seamless edge fitting when loading the silicon wafer and further improving the positioning stability of the silicon wafer, preventing vibration and displacement. The insert 13 can adsorb the silicon wafer from the back of the boat body 11 and seal the boat after the silicon wafer is placed, thereby preventing plating around the wafer-to-boat contact surface.

[0023] Furthermore, the insert 13 also includes engaging portions 133 disposed on both sides of the insert body 131. The boat body 11 includes a slot 112 corresponding to the engaging portion 133. The thickness of the engaging portion 133 is less than the thickness of the insert body 131, allowing the slot 112 to be disposed. More specifically, the length of the engaging portion 133 does not exceed the length of the insert body 131, and the width of the engaging portion 133 near the end 133b of the insert bearing portion 132 is less than the width of the engaging portion 133 near the end 133a of the insert body 131, facilitating the insertion of the engaging portion 133 into itself. The engaging portion 133 ensures stable fixation of the insert 13, preventing loosening during the coating process and ensuring a tight connection between the insert 13 and the boat body 11, further sealing gaps and improving the anti-winding coating effect. In addition, it enables the insert 13 to be quickly installed, removed, and reused, thereby improving maintenance efficiency.

[0024] Specifically, the support portion 111 is located at the center of the boat body 11, and multiple support positions 111 are uniformly arranged along the length direction of the boat body 11. Each support portion 111 can hold one silicon-based wafer, and multiple silicon-based wafers can be loaded along the length direction of a graphite boat 10, meaning that multiple silicon-based wafers can be deposited at once, improving the efficiency of silicon-based wafer deposition. Simultaneously, the uniform arrangement along the length direction ensures the uniformity of the thermal and electric fields during the deposition of multiple wafers, and improves the consistency and yield of simultaneous processing of multiple wafers. Furthermore, the support portion 111 is a circular groove structure with the same or different diameters, enabling it to adapt to wafers of different sizes. The circular grooves also provide multi-point support, ensuring wafer stability and preventing slippage. In this embodiment, the boat body 11 is provided with four support positions 111a of a first diameter and three support positions 111b of a second diameter, wherein the first diameter is smaller than the second diameter.

[0025] Furthermore, the graphite boat 10 also includes process points 40 for precise positioning and fixing of the silicon-based wafer, and the boat body 11 is provided with positioning holes 113 corresponding to the process points 40. The process points 40 enable precise placement and alignment, ensuring the accuracy of the coating pattern and reducing defects caused by wafer misalignment. The combination of the process points 40 and the insert 13 ensures precise wafer positioning and fixing, preventing wafer movement or misalignment during coating and improving coating consistency. In this embodiment, each carrier portion 111 includes three positioning holes 113, including a support positioning hole 113 located below the carrier portion 111 and side positioning holes 113 located on both sides of the carrier portion 111. The three positioning holes 113 correspond to the three process points 40, forming a stable three-point positioning structure, which prevents wafer rotation or tilting, ensures wafer fit with the insert 13, and closes edge gaps.

[0026] Furthermore, the ceramic sleeve 20 is made of high-temperature resistant ceramic material and is used to isolate adjacent boat pieces, ensuring electrical insulation between the boat pieces and preventing short circuits or current leakage. Graphite nuts 50 are provided at both ends of the ceramic rod 30, which are used to lock and fix multiple graphite boat pieces 10. The ceramic rod 30 and the graphite nuts 50 are connected by threads, ensuring a tight and stable graphite boat structure and facilitating disassembly and maintenance. In addition, the ceramic rod 30 is insulated, preventing electrode short circuits; the graphite nuts 50 are high-temperature resistant and corrosion-resistant, improving the device's lifespan; the ceramic sleeve 20 has good insulation performance, high hardness, and excellent wear resistance, improving its service life as an insulating sleeve; through the ceramic rod 30, ceramic sleeve 20, and graphite nuts 50, all boat pieces are fixed into a whole, ensuring the overall structure of the graphite boat is stable, improving durability, and preventing mechanical deformation under high-temperature environments.

[0027] Specifically, the graphite boat 10 includes a positive electrode graphite boat 101 for connection to the positive electrode and a negative electrode graphite boat 102 for connection to the negative electrode. In the positive electrode graphite boat 101, the electrode connecting block 12 is a positive electrode connecting plate 121, and two positive electrode connecting plates 121 are respectively disposed on both sides of the boat body 11 and located at the upper part of the boat body 11. In the negative electrode graphite boat 102, the electrode connecting plate is a negative electrode connecting plate 122, and two negative electrode connecting plates 122 are disposed on both sides of the boat body 11 and located at the lower part of the boat body 11. It should be noted that during installation, the positive electrode graphite boat 101 and the negative electrode graphite boat 102 are arranged alternately, that is, the installation is performed in an alternating sequence of positive electrode graphite boat 101 and negative electrode graphite boat 102.

[0028] The graphite boat also includes spacers 60, which are used to assist in connecting graphite boat sheets 10 with the same electrode. The spacers 60 are connected and fixed to each other by the ceramic rod 30 and the graphite nut 50. The multi-point fixing by the spacers 60 improves the rigidity of the entire boat, ensures that the potential of the sheets with the same electrode is consistent, reduces voltage differences, and improves the stability of the electric field.

[0029] The assembly process of the graphite boat is as follows: Multiple graphite boat sheets 10 are arranged in an array sequence, ensuring their positive and negative poles face in the same direction and their electrode connections are on the same side or both sides. A ceramic sleeve 20 is inserted between every two adjacent graphite boat sheets to achieve electrical insulation and spacing control. A ceramic rod 30 passes sequentially through the through holes on the ceramic sleeve 20 and the graphite boat sheet 10, connecting the boat sheets in series. Graphite nuts 50 are tightened at both ends of the ceramic rod 30 to achieve overall fixation. Inserts 13 are inserted into the slots 112 at the top of the boat sheet body 11, ensuring the engaging part 133 matches and engages with the slot 112, guaranteeing stable fixation of the inserts 13. Process points 40 are embedded into the three pre-set positioning holes 113 around each bearing part 111 to achieve three-point positioning. The positive electrode connecting plate 121 of the positive electrode graphite boat 101 is connected to the positive terminal of the power supply; the negative electrode connecting plate 122 of the negative electrode graphite boat 102 is connected to the negative terminal of the power supply; spacers 60 are used to assist in the connection between graphite boats of the same electrode and are fixed by ceramic rods 30 to improve the electrical consistency and structural stability of the entire boat.

[0030] The working process of the graphite boat is as follows: the silicon-based wafer is placed sequentially into multiple support portions 111 on the boat body 11 with the assistance of the insert 13; the positive and negative electrode plates of the graphite boat are connected to the positive and negative terminals of the power supply respectively, and the current generated after power is turned on passes through the boat body 11; vapor deposition is performed in the vacuum chamber, and the material is deposited on the wafer surface in gas form; after the coating is completed, the power is turned off and the graphite boat is allowed to cool; the wafers are taken out sequentially and the coating quality is checked.

[0031] In this design, the insert 13's insert support portion 132 and the support portion 111 together provide stable support for the wafer; the process point 40 and the wafer edge achieve three-point precision positioning to prevent slippage and rotation; the insert 13 adsorbs the wafer from the back of the boat and seals the edge, effectively reducing wafer edge plating during deposition. The closed structure between the insert 13 and the boat body 11 prevents excess material from entering below the wafer edge; the process point 40 ensures that the wafer does not move during deposition, ensuring uniform coating thickness and morphology; multiple support positions 111 are evenly arranged along the length direction, resulting in uniform heating and electric field distribution across multiple wafers, improving overall yield and consistency. The insert 13 can be quickly disassembled, cleaned, and reused, improving system maintenance efficiency; if the boat needs to be replaced or cleaned, the graphite nut 50 can be removed, and the ceramic rod 30 can be taken out to complete the disassembly and assembly.

[0032] In summary, the graphite boat for silicon-based wafer coating provided by this invention, through the detachable structure of the insert 13 and the boat body 11, allows the insert 13 to lift the wafer from the back and seal the edge of the graphite boat 10, forming a sealed cavity. This ensures precise wafer fixation, avoids back-side plating and displacement, and effectively solves the problem of back-side plating. Simultaneously, ceramic sleeves 20 and ceramic rods 30 insulate the graphite boat 10, ensuring electric field control and equipment safety during the coating process. The graphite boat for silicon-based wafer coating provided by this invention has a modular and easy-to-assemble overall structure, forming a robust mechanical structure that enhances equipment lifespan and reliability. The detachable insert 13 allows for convenient maintenance and cleaning, reducing coating residue and improving production efficiency. Suitable for high-precision semiconductor manufacturing, it effectively improves the stability and efficiency of the coating process, meeting the demands of modern microelectronics industry for high-quality thin film preparation.

[0033] The above description is merely a preferred embodiment of the present invention and does not limit the patent scope of the present invention. Any equivalent structural or procedural transformations made based on the content of the present invention's specification and drawings, or direct or indirect applications in other related technical fields, are similarly included within the patent protection scope of the present invention.

Claims

1. A graphite boat for silicon-based wafer coating, characterized in that, It includes: Graphite boat sheets, and an array of multiple graphite boat sheets are arranged; A ceramic sleeve is disposed between adjacent graphite boat sheets to separate adjacent graphite boat sheets; A ceramic rod, passing through the ceramic sleeve, is used to connect the graphite boat sheets into a whole; The graphite boat includes a boat body, an electrode connection portion, and inserts detachably connected to the boat body. The electrode connection portion is connected to the positive and negative terminals of an external power supply, respectively. The boat body is provided with multiple support portions for loading silicon-based wafers, and the inserts are detachably connected to the support portions. The insert is disposed at the top of the boat body. The insert includes an integral insert body and an insert carrier. The thickness of the insert body is the same as the thickness of the boat body, and the thickness of the insert carrier is the same as the thickness of the carrier. The insert carrier and the carrier are used together to load the silicon-based wafer.

2. The graphite boat for silicon-based wafer coating according to claim 1, characterized in that, The insert also includes engaging portions disposed on both sides of the insert body portion, and the boat body includes a slot corresponding to the engaging portion, the thickness of the engaging portion being less than the thickness of the insert body portion.

3. The graphite boat for silicon-based wafer coating according to claim 1, characterized in that, The supporting part is located in the middle of the boat body, and multiple supporting parts are evenly arranged along the length direction of the boat body.

4. The graphite boat for silicon-based wafer coating according to claim 1, characterized in that, The supporting part is a circular groove structure with the same or different diameters.

5. The graphite boat for silicon-based wafer coating according to claim 1, characterized in that, The graphite boat also includes process points for precise positioning and fixing of the silicon-based wafer, and the boat body is provided with positioning holes corresponding to the process points.

6. The graphite boat for silicon-based wafer coating according to claim 5, characterized in that, Each of the aforementioned support portions includes three positioning holes, including a support positioning hole located below the support portion and side positioning holes located on both sides of the support portion.

7. The graphite boat for silicon-based wafer coating according to claim 1, characterized in that, Graphite nuts are provided at both ends of the ceramic rod, and the graphite nuts are used to lock and fix the multiple graphite boat pieces.

8. The graphite boat for silicon-based wafer coating according to claim 1, characterized in that, The graphite boat includes a positive electrode graphite boat for connection to the positive electrode and a negative electrode graphite boat for connection to the negative electrode; in the positive electrode graphite boat, the electrode connecting block is a positive electrode connecting plate, and two positive electrode connecting plates are respectively disposed on both sides of the boat body and located at the upper part of the boat body; in the negative electrode graphite boat, the electrode connecting plate is a negative electrode connecting plate, and two negative electrode connecting plates are disposed on both sides of the boat body and located at the lower part of the boat body.

9. The graphite boat for silicon-based wafer coating according to claim 7 or 8, characterized in that, The graphite boat also includes spacers, which are used to assist in connecting graphite boat sheets with the same electrode. The spacers are connected and fixed to each other by the ceramic rod and the graphite nut.

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