A gas inlet pipe structure for preparing semiconductor silicon wafer and a growth furnace

Abstract

The application provides a gas inlet pipe structure for semiconductor silicon wafer preparation and a growth furnace. The gas inlet pipe structure comprises a first pipe body and a second pipe body to form a combined body with an annular gap cavity, and a third pipe body connected to the second pipe body in the combined body. The annular gap cavity is closed at one end away from the third pipe body. The gas inlet pipe structure for semiconductor silicon wafer preparation has a double-layer coaxial structure, which can effectively disperse thermal stress, enhance structural strength, and reduce the risk of fracture. The radial hole realizes pressure balance and airflow buffering, and improves the heat transfer efficiency. The overall structure significantly prolongs the service life of the gas inlet pipe, reduces the maintenance frequency, and improves the continuity of semiconductor production and the yield of products.

Description

Technical Field

[0001] This application belongs to the field of semiconductor manufacturing technology, and in particular relates to an inlet pipe structure and a growth furnace for preparing semiconductor silicon wafers. Background Technology

[0002] In the growth of polycrystalline silicon semiconductors, the inlet pipe, as a key component for transporting silane gas, is subjected to harsh environments of high temperature, airflow impact, and thermal cycling for extended periods. Current technologies commonly employ a single-layer quartz tube structure, which suffers from problems such as thermal stress concentration, insufficient structural strength, and susceptibility to fatigue fracture. Specifically, at high temperatures, uneven thermal expansion causes silane gas to adhere to the inner and outer walls, forming a polycrystalline silicon layer. This results in localized stress concentration with random orientation, easily leading to cracks or even fractures in the tube. Furthermore, the single-layer tube structure cannot effectively disperse external mechanical impacts and thermal cycling loads, resulting in a short service life and frequent replacements. This not only incurs high maintenance costs but also severely impacts production efficiency, product yield, and the stability of continuous equipment operation. Therefore, a novel inlet pipe structure is urgently needed to improve its thermal stability and mechanical strength, reduce maintenance costs, and ensure the continuity and reliability of semiconductor production. Summary of the Invention

[0003] This application provides an air inlet pipe structure and a growth furnace for semiconductor silicon wafer preparation, which is particularly suitable for the preparation of low-pressure deposited polycrystalline silicon. It can not only improve the resistance to impact stress and fatigue, but also realize the dual-layer control of airflow or pressure, thereby extending service life, reducing maintenance frequency, ensuring production continuity, and reducing production costs.

[0004] To solve at least one of the above-mentioned technical problems, the technical solution adopted in this application is:

[0005] An air inlet pipe structure for semiconductor silicon wafer fabrication includes a first pipe body and a second pipe body forming an assembly with an annular gap cavity, and a third pipe body connected to the second pipe body in the assembly; wherein the end of the annular gap cavity away from the third pipe body is a closed structure.

[0006] Furthermore, the first tube body and the second tube body are arranged coaxially, and the first tube body is sleeved outside the second tube body.

[0007] Furthermore, the length of the third tube is 3%-10% of the length of the intake pipe.

[0008] Furthermore, the maximum outer diameter of the third tube is smaller than the inner diameter of the first tube and larger than the maximum outer diameter of the second tube.

[0009] Furthermore, the connection between the outer wall of the third tube and the second tube is a frustum-shaped connection structure.

[0010] Furthermore, the outer diameter of the third tube is φ14.5mm-14.8mm.

[0011] Furthermore, at least one radial hole is formed on the outer wall surface of the first tube, the radial hole being located at one end of the first tube near the third tube.

[0012] Furthermore, the distance from the radial hole to the end of the first tube near the third tube is 10mm-30mm.

[0013] Furthermore, the diameter of the radial hole is φ1mm-φ3mm.

[0014] Furthermore, a radial blind groove is provided on the outer wall surface of the third tube, and the distance from the groove to the outer end face of the third tube is 25mm-35mm.

[0015] Furthermore, the wall thickness of the first tube is less than that of the second tube, and the thickness of the annular gap cavity is not greater than that of the first tube.

[0016] Furthermore, the wall thickness of the first tube is 0.5mm-2mm; the wall thickness of the second tube is 2mm-4mm.

[0017] An induction furnace includes an air inlet pipe and an induction furnace as described above, wherein the third pipe body is interference-fitted with the mounting interface of the induction furnace body.

[0018] Furthermore, the mounting interface includes a body, on which an annular groove adapted to the third tube is constructed, and an air passage is constructed on the axis of the body; on the wall surface of the annular groove where the maximum diameter is located, a boss is constructed to engage with the blind hole groove on the third tube.

[0019] The inlet pipe structure and growth furnace for semiconductor silicon wafer preparation designed in this application are particularly suitable for the preparation of low-pressure deposited polycrystalline silicon. Through the double-layer coaxial structure design, thermal stress can be effectively dispersed, impact resistance and fatigue resistance can be improved, structural strength can be enhanced, and the risk of fracture can be reduced. The radial holes realize pressure balance and airflow buffering, improving heat transfer efficiency. The blind hole groove in the third tube and the boss in the mounting interface are designed to further ensure the accuracy and stability of assembly. The overall structure can significantly extend the service life of the inlet pipe, reduce the maintenance frequency, and improve the continuity of semiconductor production and product yield. Attached Figure Description

[0020] Figure 1 This is a length cross-sectional view of the intake pipe structure in this application;

[0021] Figure 2 This is a cross-sectional view of the closed end of AA in this application;

[0022] Figure 3 This is a cross-sectional view of the BB radial hole in this application;

[0023] Figure 4 This is a cross-sectional view of the CC blind hole groove in this application;

[0024] Figure 5 This is a schematic diagram of the connection between the air inlet pipe and the growth furnace in this application;

[0025] Figure 6 This is a perspective view of the installation interface in this application;

[0026] Figure 7 This is a cross-sectional view of the installation interface in this application.

[0027] In the picture:

[0028] 10. First tube body; 11. Welded end; 12. Radial hole

[0029] 20, Second tube body; 30, Annular gap cavity; 40, Third tube body

[0030] 41. Blind hole groove; 50. Furnace body; 51. Installation interface

[0031] 52. Annular groove; 53. Boss; 54. Channel

[0032] 55. Exhaust port 1, Inlet pipe 2, Growth furnace Detailed Implementation

[0033] The present application will now be described in detail with reference to the accompanying drawings and specific embodiments.

[0034] This embodiment proposes an inlet pipe structure for semiconductor silicon wafer preparation, mainly suitable for the preparation of low-pressure deposited polycrystalline silicon, such as... Figure 1-5As shown, the air inlet pipe 1 includes an assembly with an annular gap cavity 30 formed by a first pipe body 10 and a second pipe body 20, and a third pipe body 40 connected to the second pipe body 20 in the assembly. All pipe bodies are made of quartz material, which is resistant to high temperatures and corrosion, and can be precision machined by milling, drilling, welding, and other methods to ensure dimensional accuracy and sealing. In use, gas is directly introduced from the lower end of the third pipe body 40, then passes through the third pipe body 40 and the second pipe body 20 in sequence, and finally flows out from the top of the second pipe body 20 into the furnace body 50 cavity in the growth furnace 2. The third tube 40 serves as the installation mating section and is directly connected to the installation interface 51. The assembly, as the main air intake section that directly contacts the growth chamber of the furnace body 50, includes not only an outer tube and an inner tube, but also an annular gap cavity 30 between the inner and outer tubes. This can improve the dispersion of high thermal stress between the inner and outer tubes, thereby enhancing the impact stress resistance and fatigue resistance of the inner and outer tubes and achieving dual-layer control of airflow and pressure. The gap cavity, as a thermal buffer layer, allows for differentiated expansion of the inner and outer tubes, reducing thermal stress concentration and the risk of breakage. Furthermore, since an exhaust port 55 of the same height as the mounting interface 51 is provided on the outer wall of the furnace body 50 near the mounting interface 51, and this exhaust port 55 is connected to an external vacuum pump, it is mainly used to discharge the waste gas in the furnace cavity. During growth, the gas concentration is relatively high at the top of the furnace body, and the gas concentration gradually decreases from the top to the bottom of the furnace body. In particular, the gas concentration is relatively low at the exhaust port position. Therefore, even though the annular gap cavity 30 is open near the third tube, very little gas enters the annular gap cavity 30 from the radial hole 12 or the open end, and polycrystalline silicon cannot be formed on the outer wall of the second tube. Polycrystalline silicon will only adhere to the outer wall of the outer tube and the inner wall of the inner tube, thereby avoiding the problem of single-tube double-sided deposition.

[0035] like Figure 1 As shown, the first tube 10 is fitted outside the second tube 20, meaning the first tube 10 is the outer tube and the second tube 20 is the inner tube. The first tube 10 and the second tube 20 are coaxially arranged and have the same length. This structure is not only easy to manufacture but also simple in process. The coaxial arrangement ensures that the thickness of the annular gap cavity 30 between the inner and outer tubes is consistent at all radial angles. This means that the heat transfer from the outer tube to the inner tube is uniform and predictable, avoiding local overheating or thermal stress concentration caused by uneven gaps. Moreover, a uniform gap is key to effectively buffering thermal stress. Furthermore, thermal expansion is also axisymmetric in high-temperature environments, which makes the deformation of the tube uniform and controllable, greatly reducing the additional bending stress caused by asymmetrical deformation.

[0036] like Figure 2As shown, at the end of the first tube 10 furthest from the third tube 40, i.e., at the top of the first tube 10, the annular gap cavity 30 is sealed by a combination of argon arc welding and flaw detection, thereby welding and fixing the inner and outer tubes together. This not only facilitates operation but also ensures the stability of the double-tube welded connection. The end of the first tube 10 closest to the third tube 40 has an open fit with the second tube 20, resulting in a structure where the upper end of the annular gap cavity 30 is a closed end 11 and the lower end is an open end.

[0037] In high-temperature environments, the temperature rise rate and final temperature of the first tube 10, directly exposed to the high temperature of the furnace, will be much higher than that of the second tube 20 encased within it. If both ends are rigidly fixed, the difference in expansion caused by the temperature difference between the inner and outer tubes will generate enormous shear stress internally, easily leading to the quartz tube cracking or crushing. The closed end 11 provides a stable mechanical connection and positioning for the first tube 10 and the second tube 20; the open lower end allows the inner tube to have a certain amount of axial expansion and contraction space relative to the outer tube, thereby compensating for the expansion difference caused by the temperature difference and greatly reducing thermal stress. Moreover, it can also reduce resonance to a certain extent and avoid the risk of fatigue fracture.

[0038] Through the lower opening of the annular gap cavity 30 and the radial hole 12 on the first tube 10, a pressure linkage environment is formed between the annular gap cavity 30, the furnace cavity, and the inner tube, thus making the annular gap cavity 30 a dynamic pressure balance chamber. When the main gas flow pressure or the furnace cavity pressure fluctuates, the gas pressure in the gap cavity can be adaptively adjusted to avoid the tube body, especially the thinner outer tube, being crushed or burst due to excessive pressure difference between the inner and outer tubes.

[0039] Furthermore, during the cleaning of the intake pipe 1, the cleaning water or solvent is sprayed into the annular gap cavity 30 through the radial hole 12. Under pressure, the cleaning fluid enters the annular gap cavity 30. Due to the small annular gap, the water flow forms a high velocity, effectively flushing away contaminants adhering to the inner wall of the outer pipe and the outer wall of the inner pipe. The flushed waste liquid flows downward along the annular gap cavity under the force of gravity and subsequent water flow, and flows out smoothly from the open end. For traditional welded sealed sandwich structures, the interior is almost impossible to clean, and once contaminated, the entire structure must be replaced. This design, through the combination of a single-end opening and radial holes, transforms a closed structure into a flushable channel, solving the maintenance problems brought about by the double-layer structure. Moreover, the cleaning process does not require disassembling the intake pipe itself, nor does it require damaging the annular weld at the top; it can be directly flushed, greatly simplifying the maintenance process and saving time and labor costs.

[0040] Furthermore, the wall thickness of the first tube 10 is less than that of the second tube 20, i.e., a structure of thin outer tube and thick inner tube is used. Since the first tube 10 mainly bears the external temperature difference stress, and the second tube 20 mainly resists the airflow impact force of the high-pressure silane inside, the thin outer tube can respond quickly to temperature changes to reduce the stress of the external temperature difference; and the inner tube can resist the impact of the internal airflow and maintain the stability of the airflow.

[0041] Preferably, the wall thickness of the first tube 10 is 0.5mm-2mm, including but not limited to 0.5mm, 0.6mm, 0.7mm, 0.8mm, 0.9mm, 1.0mm, 1.1mm, 1.2mm, 1.3mm, 1.4mm, 1.5mm, 1.6mm, 1.7mm, 1.8mm, 1.9mm, and 2.0mm.

[0042] The wall thickness of the second tube 20 is 2mm-4mm, including but not limited to 2.0mm, 2.1mm, 2.2mm, 2.3mm, 2.4mm, 2.5mm, 2.6mm, 2.7mm, 2.8mm, 2.9mm, 3.0mm, 3.1mm, 3.2mm, 3.3mm, 3.4mm, 3.5mm, 3.6mm, 3.7mm, 3.8mm, 3.9mm, and 4.0mm.

[0043] Furthermore, the thickness of the annular gap cavity 30 is not greater than the wall thickness of the first tube 10, that is, the thickness of the annular gap cavity 30 is ≤ the wall thickness of the first tube 10 < the wall thickness of the second tube 20. The gap cavity is a non-through space. Since the outer tube preferentially deforms elastically during thermal deformation, the gap setting can prevent the inner tube from being squeezed; at the same time, it can also limit the expansion difference between the inner and outer tubes, which can prevent the stress at the closed end 11 from exceeding the limit and prevent the weld from cracking.

[0044] Preferably, the thickness of the annular gap cavity 30 is 0.2-1.5 mm, including but not limited to 0.2, 0.3 mm, 0.4 mm, 0.5 mm, 0.6 mm, 0.7 mm, 0.8 mm, 0.9 mm, 1.0 mm, 1.1 mm, 1.2 mm, 1.3 mm, 1.4 mm, and 1.5 mm.

[0045] Because the annular gap 30 has a small opening and the radial hole 12 is small, only a small amount of gas can seep into the annular gap from the lower opening or through the radial hole. Furthermore, even when gas enters the gap, it preferentially forms a deposition layer on the inner wall of the outer tube, unlike the severe deposition layers on both the inner and outer walls in a single tube. This weak airflow can form a buffer layer within the cavity, further equalizing the temperature distribution and preventing impurities from flowing back into or depositing into the gap, thus maintaining the cleanliness and functional stability of the cavity.

[0046] Furthermore, the maximum outer diameter D3 of the third tube 40 is smaller than the inner diameter D1 of the first tube 10 and larger than the maximum outer diameter D2 of the second tube 20, resulting in a variable diameter connection at the junction of the second tube 20 and the third tube 40. This variable diameter structure forms a frustum at the junction of the second tube 20 and the third tube 40, which increases the contact and connection area during welding, making the overall structure stronger and more resistant to airflow impact and mechanical vibration; it also ensures that the reactant gas can freely pass through the annular gap cavity 30.

[0047] Gas enters the annular gap cavity 40 from the variable diameter section, which can significantly reduce turbulence and eddies, reduce pressure loss, and make the airflow more stable, meeting the stringent requirements of semiconductor processes for airflow stability. If there is a sudden necking, a dead zone will be generated at the connection, which will lead to polysilicon accumulation. The smooth variable diameter design effectively eliminates this dead zone and reduces potential sources of contamination.

[0048] Preferably, the inner diameter D1 of the first tube 10 is φ14.5mm-φ15.5mm, and its dimensions include, but are not limited to, φ14.5mm, φ14.6mm, φ14.7mm, φ14.8mm, φ14.9mm, φ15mm, φ15.1mm, φ15.2mm, φ15.3mm, φ15.4mm, and φ15.5mm.

[0049] Preferably, the outer diameter D2 of the second tube 20 is φ13.5mm-φ14.5mm, and its dimensions include, but are not limited to, φ13.5mm, φ13.6mm, φ13.7mm, φ13.8mm, φ13.9mm, φ13mm, φ14.1mm, φ14.2mm, φ14.3mm, and φ14.4mm.

[0050] like Figure 1 , 5 As shown, the third tube 40 is the mounting end, designed to facilitate an interference fit with the mounting structure 41 in the growth furnace 2, ensuring the assembly accuracy of the air inlet pipe 1 and the growth furnace body. The outer diameter D3 of this third tube 40 is φ14.5mm-φ14.8mm, preferably with a safety tolerance diameter of φ14.8mm. -0.3mm By machining the outer diameter of the third tube 40 within a very small and precise range, it is ensured that the air inlet pipe can be seamlessly inserted into or connected to the mounting interface 41 of the furnace body 40. It cannot be too loose, otherwise it will lead to air leakage or shaking; nor can it be too tight, otherwise it will lead to installation difficulties or excessive installation stress, or even crack the interface. This structure achieves a sealed connection with the furnace body, effectively reducing vibration and installation stress, avoiding the resulting risks of breakage and leakage, while also considering ease of manufacture and economy.

[0051] In this embodiment, the inner diameters of the second tube 20 and the third tube 40 are the same, and the inner diameter D4 of the second tube 20 is φ7.5mm-φ8.5mm, including but not limited to φ7.5mm, φ7.6mm, and φ8.5mm.

[0052] 7.7mm, φ7.8mm, φ7.9mm, φ8mm, φ8.1mm, φ8.2mm, φ8.3mm, φ8.4mm, φ8.5mm. Preferably, the inner diameter of one end of the second tube 20 has no machining requirements, as long as the dimensions meet the standard. However, at one end of the third tube 40, the inner diameter tolerance requirement is an upper tolerance, such as an inner diameter range of φ8.0mm-φ8.3mm, i.e., φ8.0mm. +0.3mm The purpose is to ensure the stability and reliability of safe cooperation.

[0053] The length L1 of the third tube 40 is 3%-10% of the length L of the intake tube 1, including but not limited to 3%, 3.5%, 4%, 4.5%, 5%, 5.5%, 6%, 6.5%, 7%, 7.5%, 8%, 8.5%, 9%, 9.5%, and 10%. Preferably, the length L of the intake pipe 1 is 1100mm-1400mm, including but not limited to 1100mm, 1110mm, 1120mm, 1130mm, 1140mm, 1150mm, 1160mm, 1170mm, 1180mm, 1190mm, 1200mm, 1210mm, 1220mm, 1230mm, 1240mm, 1250mm, 1260mm, 1270mm, 1280mm, 1290mm, 1300mm, 1310mm, 1320mm, 1330mm, 1340mm, 1350mm, 1360mm, 1370mm, 1380mm, 1390mm, and 1400mm.

[0054] like Figure 3 , 5 As shown, the gas flows directly upward through the inner walls of the third tube 40 and the second tube 20. The top of the annular gap cavity 30 is sealed and welded. At least one radial hole 12 is provided on the outer wall of the first tube 10. The radial hole 12 can not only be used as a cleaning hole when cleaning the air inlet pipe 1, but also as a process hole to adjust the gas pressure difference between the inner and outer tubes during growth, so as to maintain the gas pressure balance between the inner and outer tubes.

[0055] Both the radial hole 12 and the open end of the annular gap cavity 30 can balance the gas pressure difference between the gap cavity and the furnace body, maintaining dynamic pressure balance and avoiding the risk of tube rupture caused by gas expansion under high growth temperatures. Furthermore, during growth gas filling, the silane gas flow flows from the inner cavity channel of the first tube 10 and diffuses from the top into the inner cavity of the furnace body 40. The gas flow in the furnace cavity can flow through the radial hole 12 and the open end into the annular gap cavity 30 to guide and buffer the gas flow, thereby assisting in regulating the pressure inside the cavity. Additionally, for the gas flow entering the annular gap cavity 30 from the radial hole 12, a uniform annular channel means that the flow resistance is isotropic, preventing turbulent eddies or local pressure anomalies, which is beneficial for achieving the designed pressure balance effect.

[0056] The distance L2 from the radial hole 12 to the end of the first tube 10 near the third tube 40 is 10mm-30mm. In this embodiment, there is one radial hole 12, which is located on one side wall of the first tube 10. The dimensions of the distance L2 include, but are not limited to, 10mm, 10.5mm, 11mm, 11.5mm, 12mm, 12.5mm, 13mm, 13.5mm, 14mm, 14.5mm, 15mm, 15.5mm, 16mm, 16.5mm, 17mm, 17.5mm, 18mm, 18.5mm, 19mm, 19.5mm, 20mm, 20.5mm, 21mm, 21.5mm, 22mm, 22.5mm, 23mm, 23.5mm, 24mm, 24.5mm, 25mm, 25.5mm, 26mm, 26.5mm, 27mm, 27.5mm, 28mm, 28.5mm, 29mm, 29.5mm, and 30mm.

[0057] Preferably, the diameter of the radial hole 12 is φ1mm-φ3mm, including but not limited to φ1mm, φ

[0058] 1.2mm, φ1.5mm, φ1.8mm, φ2mm, φ2.2mm, φ2.5mm, φ2.8mm, φ3mm.

[0059] like Figure 4 As shown, a radial annular blind hole groove 41 is provided on the outer wall surface of the third tube 40, and the distance L3 from the groove to the outer end of the third tube is 25mm-35mm. This dimension includes, but is not limited to, 25mm, 25.5mm, 26mm, 26.5mm, 27mm, 27.5mm, 28mm, 28.5mm, 29mm, 29.5mm, 30mm, 30.5mm, 31mm, 31.5mm, 32mm, 32.5mm, 33mm, 33.5mm, 34mm, 34.5mm, and 35mm.

[0060] Preferably, the height L4 of the blind slot 41 is 8mm-12mm, including but not limited to 8mm, 8.5mm, 9mm, 9.5mm, 10mm, 10.5mm, 28mm, 28.5mm, 29mm, 29.5mm, and 30mm. The purpose of the blind slot 41 is to ensure that the boss 53 on the mounting interface 51 is securely engaged with the blind slot 41 when the intake pipe 1 is installed, preventing the intake pipe 1 from shaking radially.

[0061] Preferably, the width W of the blind hole groove 41 is 3mm-5mm, and its dimensions include, but are not limited to, 3.1mm, 3.2mm, 3.3mm, 3.4mm, 3.5mm, 3.6mm, 3.7mm, 3.8mm, 3.9mm, 4.0mm, 4.1mm, 4.2mm, 4.3mm, 4.4mm, 4.5mm, 4.6mm, 4.7mm, 4.8mm, 4.9mm, and 5.0mm. The depth H of the blind hole groove 41 is 1.5mm-2.0mm, and its dimensions include, but are not limited to, 1.5mm, 1.6mm, 1.7mm, 1.8mm, 1.9mm, and 2.0mm.

[0062] Furthermore, the radial hole 12 and the blind hole groove 41 can be in the same column or not in the same column along the height direction of the air intake pipe 1, which is not specifically limited here.

[0063] This application introduces a double-layer tube structure, which transforms the single-layer tube, where both the inner and outer walls are coated with polycrystalline silicon layers, into a single-layer tube where the outer wall of the first tube 10 (outer layer) and the inner wall of the second tube 20 (inner layer) are coated with polycrystalline silicon layers respectively. This avoids the technical problem of uneven thermal expansion of the two walls in a single-layer tube. It also solves the technical problem of existing single-layer tubes being prone to uneven thermal expansion, leading to stress concentration in random directions and making them easily breakable. The double-layer tube can alleviate the difference in thermal expansion; moreover, the double-layer tubes work together to bear the load, further resisting impact stress, balancing internal and external pressure, providing good buffering effect, improving overall fatigue resistance, and extending its service life.

[0064] A growth furnace, such as Figure 5 As shown, the structure includes the inlet pipe 1 and the growth furnace 2 as described above. The mounting interface 51 between the third tube 40 and the furnace body 50 in the growth furnace 2 is an interference fit. An interference fit relies solely on the elastic deformation of the material itself to generate a large contact pressure on the mating surface. This pressure is sufficient to effectively prevent gas leakage. Furthermore, the coefficient of thermal expansion of the quartz material may differ from that of the mounting interface 51 (which is usually also ceramic), but a precise interference fit ensures a good seal at operating temperatures. The interference fit eliminates clearance, making the inlet pipe 1 and the furnace body 50 a highly rigid whole, effectively preventing any minor loosening or shaking; it also effectively prevents the quartz tube from fatigue-breaking due to vibration.

[0065] like Figure 6-7 As shown, the mounting interface 51 includes a body, on which an annular groove 52 adapted to the third tube 40 is constructed, and a ventilation channel 54 is constructed on the axis of the body. Furthermore, on the wall surface of the annular groove 52 where the maximum diameter is located, a boss 53 is constructed to engage with the blind hole groove 41 on the third tube 40, which can further improve installation stability and sealing.

[0066] Table 1 shows a comparison of the service life of the existing single-layer air inlet pipe and the double-layer air inlet pipe described in this application under the same growth conditions; note that the service life is pure usage time and does not include downtime. As can be seen from the table, the service life of the existing single-layer air inlet pipe is 100-120 hours, while the service life of the double-layer air inlet pipe described in this application is 150-180 hours. Clearly, the service life of the double-layer air inlet pipe is 1.5 times that of the existing single-layer air inlet pipe.

[0067] Table 1 Comparison of results between the intake pipe of this application and the prior art under the same conditions.

[0068]

[0069] The inlet pipe structure and growth furnace for semiconductor silicon wafer preparation designed in this application are particularly suitable for the preparation of low-pressure deposited polycrystalline silicon. Through the double-layer coaxial structure design, thermal stress can be effectively dispersed, impact resistance and fatigue resistance can be improved, structural strength can be enhanced, and the risk of fracture can be reduced. The radial holes realize pressure balance and airflow buffering, improving heat transfer efficiency. The blind hole groove in the third tube and the boss in the mounting interface are designed to further ensure the accuracy and stability of assembly. The overall structure can significantly extend the service life of the inlet pipe, reduce the maintenance frequency, and improve the continuity of semiconductor production and product yield.

[0070] The embodiments of this application have been described in detail above. These descriptions are merely preferred embodiments and should not be construed as limiting the scope of this application. All equivalent variations and modifications made within the scope of this application should still fall within the patent coverage of this application.

Claims

1. An air inlet pipe structure for semiconductor silicon wafer fabrication, characterized in that, The assembly includes a first tube and a second tube forming an annular gap cavity, and a third tube connected to the second tube in the assembly; wherein the end of the annular gap cavity away from the third tube is a closed structure. At least one radial hole is formed on the outer wall surface of the first tube body, and the radial hole is located at one end of the first tube body near the third tube body; A radial blind groove is provided on the outer wall surface of the third tube.

2. The gas inlet tube structure for preparing a semiconductor silicon wafer according to claim 1, wherein The first tube and the second tube are arranged coaxially, and the first tube is sleeved outside the second tube.

3. The inlet pipe structure for semiconductor silicon wafer fabrication according to claim 1 or 2, characterized in that, The length of the third tube is 3%-10% of the length of the intake pipe.

4. The inlet pipe structure for semiconductor silicon wafer fabrication according to claim 3, characterized in that, The maximum outer diameter of the third tube is smaller than the inner diameter of the first tube and larger than the maximum outer diameter of the second tube.

5. The inlet pipe structure for semiconductor silicon wafer fabrication according to claim 4, characterized in that, The connection between the outer wall of the third tube and the second tube is a frustum-shaped connection structure.

6. The inlet pipe structure for semiconductor silicon wafer fabrication according to claim 5, characterized in that, The outer diameter of the third tube is φ14.5mm-14.8mm.

7. An inlet pipe structure for semiconductor silicon wafer fabrication according to any one of claims 1-2 and 4-6, characterized in that, The distance from the radial hole to the end of the first tube near the third tube is 10mm-30mm.

8. The inlet pipe structure for semiconductor silicon wafer fabrication according to claim 7, characterized in that, The diameter of the radial hole is φ1mm-φ3mm.

9. An inlet pipe structure for semiconductor silicon wafer fabrication according to any one of claims 1-2, 4-6, and 8, characterized in that, The distance from the blind hole groove to the outer end face of the third tube is 25mm-35mm.

10. The inlet pipe structure for semiconductor silicon wafer fabrication according to claim 1, characterized in that, The wall thickness of the first tube is less than that of the second tube, and the thickness of the annular gap cavity is not greater than that of the first tube.

11. The inlet pipe structure for semiconductor silicon wafer preparation according to claim 10, characterized in that, The first tube has a wall thickness of 0.5mm-2mm; the second tube has a wall thickness of 2mm-4mm.

12. A growth furnace, characterized in that, It includes an air inlet pipe and an growth furnace as described in any one of claims 1-11, wherein the third pipe body is interference-fitted with the furnace body of the growth furnace.

13. The growth furnace according to claim 12, characterized in that, The installation interface includes a body, on which an annular groove adapted to the third tube is constructed, and an air passage is constructed on the axis of the body; on the wall surface of the annular groove where the maximum diameter is located, a boss is constructed to engage with the blind hole groove on the third tube.

Images