A continuous feeding system for crystal growth by Czochralski method

Abstract

The invention discloses a continuous feeding system for crystal pulling growth, and relates to the technical field of feeding devices for crystal pulling growth. In order to solve the problem that the feeding device in the prior art can realize the addition of molten material, but the molten material also needs an external heating device, which will consume a lot of energy, and the added melt entering during growth is likely to cause fluctuations in the melt in the crucible, thereby affecting the effect of growing crystals, a heating mechanism is arranged inside the growth furnace shell, an upper heating mechanism is arranged at the upper end of the heating mechanism, a feeding tank is arranged outside the upper heating mechanism, a crucible is arranged inside the upper heating mechanism, three melt feeding pipes are arranged in an annular shape at the bottom end of the crucible, three melt siphon pipes are arranged in an annular shape inside the feeding tank, the lower end of the melt siphon pipe is sealed and connected with a feed pipe, and one end of the feed pipe is sealed and connected to the bottom of the melt feeding pipe through a current limiting mechanism.

Description

Technical Field

[0001] The invention relates to the technical field of crystal Czochralski feeding devices for crystal growth, in particular to a continuous feeding system for crystal Czochralski growth. Background Art

[0002] The crystal pulling method is a method of growing crystals by pulling seed crystals from the melt. The growth equipment includes: crucible, melt, seed crystal and crystal pulling mechanism, heater and power control, temperature control system, furnace body and oxygen control system, post-heater, etc. The raw materials to be grown are placed in a suitable crucible for melting, oriented seed crystals are installed, seed crystal rods are lowered, inoculated, shoulders are placed, and then crystals that meet the requirements are grown in equal diameters. The crystal pulling mechanism is a set of precise mechanical devices, which not only requires high machining accuracy, but also requires automatic control of the electromechanical drive system, and automatic adjustment with the electronic weighing system of the crucible and crystal. Therefore, this part is one of the most important parts of the modern pulling furnace. The pulling speed and rotation speed affect the shape of the solid-liquid interface, and the interface state is the key factor in crystal growth. Crystals should grow on a flat interface. A curved interface will cause uneven radial impurities and inconsistent colors inside and outside the synthetic gem crystal. .

[0003] The Chinese patent publication number is CN206635463U, which discloses a feeder for a crystal growth furnace, including a body, a material box located on the top of the body, and a sealing cover located on the top of the material box. A controller is provided on one side of the material box, and a vacuum extractor connected to the body is provided on the top of the body on one side of the material box; a sealing flange is provided on one side of the body, a linear motor electrically connected to the controller is installed inside the body, a feed pipe is provided above the linear motor, and a discharge pipe is provided at the end of the feed pipe extending out of the sealing flange. The beneficial effect is that the utility model can determine the feeding position by observing the inside of the crystal growth furnace through the design of a visual melt feeding pipe, and manually adjust the feeding position to improve the feeding accuracy. At the same time, it can be sealed during feeding, avoiding the impact on the internal environment of the crystal growth furnace and improving the growth quality of the crystal inside the crystal growth furnace.

[0004] The above-mentioned prior art solutions have the following defects: the molten material can be added through the above-mentioned feeding device, but when the molten material also requires an external heating device, a large amount of energy will be consumed. At the same time, the added melt entering during growth is likely to cause fluctuations in the melt in the crucible, thereby affecting the effect of growing crystals. Therefore, we propose a continuous feeding system for crystal pulling growth to solve the above-mentioned problems. Summary of the invention

[0005] The object of the present invention is to provide a continuous feeding system for crystal pulling growth, so as to solve the problem proposed in the above background technology that the feeding device in the prior art can realize the addition of molten material, but when the molten material also needs an external heating device, a large amount of energy will be consumed. At the same time, the added melt during growth is likely to cause fluctuations in the melt in the crucible, thereby affecting the effect of growing crystals.

[0006] To achieve the above-mentioned purpose, the present invention provides the following technical solutions: a continuous feeding system for crystal pulling growth, comprising a growth furnace shell, a heating mechanism is arranged inside the growth furnace shell, an upper heating mechanism is arranged at the upper end of the heating mechanism, a feeding tank is arranged outside the upper heating mechanism, a crucible is arranged inside the upper heating mechanism, three melt feeding pipes are arranged in a ring at the bottom end of the crucible, and the lower ends of the melt feeding pipes pass through and extend to the outside of the crucible fixing seat, three melt siphons are arranged in a ring inside the feeding tank, the lower ends of the melt siphons are sealedly connected to the feed pipe, and one end of the feed pipe is sealedly connected to the bottom of the melt feeding pipe through a current limiting mechanism.

[0007] Preferably, a seed crystal clamp is disposed inside the upper end of the growth furnace shell, a seed crystal is disposed below the seed crystal clamp, and the seed crystal is located above the crucible.

[0008] Preferably, a crucible fixing seat is provided below the crucible, a feeding tank fixing seat is provided below the feeding tank, a driving motor is provided at the middle position below the growth furnace shell, a driving rod is transmission-connected above the output end of the driving motor, and the driving rod passes through and extends to the interior of the growth furnace shell and is connected to the crucible fixing seat by a key, a feeding tank support frame is mounted on the outside of the middle position of the driving rod, and the feeding tank support frame is fixedly connected to the feeding tank fixing seat.

[0009] Preferably, a first lower heating mechanism is arranged on the outer side of the lower end of the heating mechanism, and the first lower heating mechanism is located below the feeding tank fixing seat, a second lower heating mechanism is arranged on the inner side of the lower end of the heating mechanism, and the second lower heating mechanism is located below the crucible fixing seat, and a driving rod groove is opened inside the second lower heating mechanism.

[0010] Preferably, a pressure plate is provided above the feeding tank, and the pressure plate is in a circular ring shape, two pressure telescopic cylinders are symmetrically provided above the pressure plate, the upper ends of the pressure telescopic cylinders are fixedly connected to the growth furnace shell, and the lower ends of the pressure telescopic cylinders are fixedly connected to the pressure plate, a pressing through hole is opened at the middle position of the pressure plate, and three melt siphon through holes are opened in a ring shape at the outer end of the pressure plate, and the melt siphon through holes are adapted to the melt siphon.

[0011] Preferably, a liquid filling tube is provided on one side of the upper end of the growth furnace shell, and one end of the liquid filling tube passes through and extends to the interior of the growth furnace shell, a liquid feeding pipe is rotatably connected below the liquid filling tube, and a feeding telescopic cylinder is provided below the liquid feeding pipe, the upper end of the feeding telescopic cylinder is rotatably connected to the liquid feeding pipe, and the lower end of the feeding telescopic cylinder is rotatably connected to the inner wall of the growth furnace shell.

[0012] Preferably, a sealing cover plate is rotatably arranged above the liquid filling tube, and the sealing cover plate is sealed and connected to the liquid filling tube, a sealing cover plate positioning block is arranged on one side above the liquid filling tube, a sealing cover plate locking block is arranged on the sealing cover plate positioning block and one side of the sealing cover plate, and the lower end of the sealing cover plate locking block is slidably connected to the sealing cover plate positioning block, and the upper end of the sealing cover plate locking block is located above the sealing cover plate.

[0013] Preferably, a feeding trough is provided inside the feeding tank, and the feeding trough is an annular trough, and the lower end of the liquid feed pipe is located above the feeding trough.

[0014] Preferably, the flow limiting mechanism is located inside the driving rod groove, and a flow limiting groove is opened inside the flow limiting mechanism, the upper end of the flow limiting groove is sealed with the melt feeding pipe, and the lower end of the flow limiting groove is sealed with the delivery pipe, the flow limiting groove includes a flow limiting area and a pressure release area, the flow limiting area and the pressure release area are spaced apart, and the flow limiting area and the pressure release area are connected, and the diameters of the multiple flow limiting areas and pressure release areas gradually decrease from the delivery pipe to the melt feeding pipe.

[0015] Compared with the prior art, the beneficial effects of the present invention are as follows: the present invention adds material blocks into the crucible and the feeding tank, starts the heating mechanism, and the high-temperature heating mechanism melts the material blocks in the crucible and the feeding tank. The added material blocks can be melted at the same time by the heating mechanism, thereby reducing the heat consumption caused by the direct addition of the melt and the need to melt the melt separately. When entering the equal-diameter process, single crystal columns with the same diameter are grown by controlling the thermal field temperature and the crystal lifting speed; the melt in the feeding tank is controlled to be fed according to the liquid level of the melt in the crucible, and the material blocks are added in advance through the liquid feed pipe and the liquid filling pipe according to the time point of the required feeding, the liquid feed pipe and the liquid filling pipe are connected to each other by the extension of the feeding telescopic cylinder, and the sealing cover plate positioning block is removed by sliding. The sealing cover plate locks the block, opens the sealing cover plate and puts the material block into the feeding tank through the liquid feed pipe and the liquid filling pipe. Due to the drive of the driving rod, the put-in material block is evenly distributed inside the feeding tank. After the added material block is melted, when the height of the melt in the feeding tank exceeds the height of the pipe in the melt siphon tube, the melt inside the feeding tank is driven to flow to the flow limiting mechanism through the feed pipe due to the air pressure difference, and at the same time, the pressurized telescopic cylinder is extended, and the pressurized telescopic cylinder drives the pressure plate to move downward, and the pressure plate enters the feeding tank to press the melt inside the feeding tank downward to promote the melt to flow into the flow limiting mechanism. The melt siphon tube is sealed and connected to the melt siphon tube through hole, and the pressure plate is sealed and connected to the inner wall of the feeding tank, which can effectively ensure the pressure on the melt. After the melt enters the flow limiting mechanism, it passes through multiple intervals in turn. The flow limiting area and pressure release area are set separately. The flow rate of the melt is limited by the flow limiting area and pressure release area with continuously shrinking diameters. When the melt enters the melt feeding pipe and the melt pressure is greater than the hydraulic pressure above the flow limiting plate above the melt feeding pipe, the flow limiting plate can be lifted up to enter the crucible. Without changing the crystal growth rate, the pulling speed of the crystal is corrected, that is, the pulling speed is increased. The feeding speed of the continuous feeding device is adjusted according to the crystal growth rate. The flow direction of a small amount of melt entering is the same as the flow direction of the melt in the crucible, thereby greatly reducing the fluctuation of the melt in the crucible caused by the entering melt, and the quality of crystals of equal diameter can be maintained. When the melt in the feeding tank is added, due to the reduction of the pressure in the feeding pipe, the flow limiting plate above the melt feeding pipe is reset, and the crystal growth rate is not changed. In the case of degree, the pulling speed of the crystal is corrected, that is, the pulling speed is reduced. When the crystal weight reaches the specified value, the crystal is pulled off to ensure the stability of the equal-diameter process. Continuous feeding is mainly in the late shoulder release and equal-diameter growth stage to increase the equal-diameter length of the crystal. In the mode of pulling and feeding at the same time, the position of the solid-liquid growth interface remains unchanged, and the amount of melt remains unchanged, thereby minimizing the fluctuation of the temperature gradient. The stable growth environment is very conducive to the crystal impurity removal and the stability of the lattice arrangement during the crystal growth process, which is conducive to obtaining high-quality crystals. Continuous feeding growth is not only conducive to obtaining high-quality crystals, but also increases the mass proportion of the equal-diameter part. Since the crystal utilization rate of the equal-diameter part is much greater than that of the shoulder or tail, increasing the mass proportion of the equal-diameter part greatly improves the utilization rate of the crystal. Continuous feeding, without changing the pulling speed,Since the time of one furnace opening is longer, the main increase is the growth quality of the equal diameter part, that is, the production efficiency of crystal growth is improved, and the output rate per unit time is improved, that is, the annual production capacity of a single device is increased under the premise of existing equipment. It solves the problem that the feeding device in the prior art can realize the addition of melt materials, but when the melt materials need to be heated externally, a large amount of energy will be consumed. At the same time, the melt added during growth is easy to cause fluctuations in the melt in the crucible, thereby affecting the effect of growing crystals. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a structural schematic diagram of the present invention;

[0017] Figure 2 For the present invention Figure 1 A partial enlarged view of area A;

[0018] Figure 3 It is a three-dimensional diagram of the feeding tank in the present invention;

[0019] Figure 4 A three-dimensional diagram of a pressure plate in the present invention;

[0020] Figure 5 It is a structural schematic diagram of the current limiting mechanism in the present invention;

[0021] Figure 6 It is a three-dimensional diagram of the heating mechanism in the present invention.

[0022] In the figure: 1. growth furnace shell; 2. crucible; 3. heating mechanism; 4. feeding tank; 5. crucible fixing seat; 6. driving rod; 7. driving motor; 8. feeding tank fixing seat; 9. feeding tank support frame; 10. melt siphon; 11. feeding pipe; 12. current limiting mechanism; 13. melt feeding pipe; 14. driving rod groove; 15. pressure plate; 16. pressure telescopic cylinder; 17. seed crystal clamp; 18. seed crystal; 19. melt siphon through hole; 20. liquid feed pipe; 21. feed telescopic cylinder; 22. liquid filling pipe; 23. sealing cover plate; 24. sealing cover plate positioning block; 25. sealing cover plate locking block; 26. feeding trough; 27. second lower heating mechanism; 28. pressing through hole; 29. ​​current limiting trough; 30. current limiting area; 31. pressure release area; 32. upper heating mechanism; 33. first lower heating mechanism. DETAILED DESCRIPTION

[0023] The technical solutions in the embodiments of the present invention will be described clearly and completely below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments.

[0024] See also Figure 1-6An embodiment of the present invention is as follows: a continuous feeding system for crystal pulling growth, comprising a growth furnace shell 1, a heating mechanism 3 is arranged inside the growth furnace shell 1, an upper heating mechanism 32 is arranged at the upper end of the heating mechanism 3, a feeding tank 4 is arranged outside the upper heating mechanism 32, a crucible 2 is arranged inside the upper heating mechanism 32, three melt feeding pipes 13 are arranged in a ring at the bottom end of the crucible 2, and the lower ends of the melt feeding pipes 13 pass through and extend to the outside of the crucible fixing seat 5, three melt siphon pipes 10 are arranged in a ring inside the feeding tank 4, the lower ends of the melt siphon pipes 10 are sealedly connected to a feed pipe 11, and one end of the feed pipe 11 is sealedly connected to the bottom of the melt feeding pipe 13 through a current limiting mechanism 12.

[0025] When in use, first add the material block into the crucible 2 and the feeding tank 4, close the growth furnace, start the heating mechanism 3, and the high-temperature heating mechanism 3 melts the material blocks in the crucible 2 and the feeding tank 4. The added material blocks can be melted at the same time by the heating mechanism 3, which reduces the heat consumption caused by the direct addition of the melt and the need to melt the melt. When entering the equal-diameter process, by controlling the thermal field temperature and the crystal lifting speed, single crystal columns with the same diameter are grown; according to the liquid level of the melt in the crucible 2, the melt in the feeding tank 4 is controlled to be fed, and the liquid is vacuumed in advance through the liquid feeding pipe 20 and the liquid filling pipe 22 according to the time point of feeding. The feed liquid is pumped in, and the extension of the feed telescopic cylinder 21 causes the liquid feed pipe 20 and the liquid filling pipe 22 to be connected relative to each other, and the liquid feed pipe 20 and the liquid filling pipe 22 are added to the feeding tank 4. Due to the drive of the drive rod 6, the input liquid is evenly distributed inside the feeding tank 4. When the height of the melt in the feeding tank 4 is higher than the height of the pipe in the melt siphon 10, the melt inside the feeding tank 4 is driven to flow to the flow limiting mechanism 12 through the feed pipe 11 due to the air pressure difference, and at the same time, the pressurizing telescopic cylinder 16 is extended, and the pressurizing telescopic cylinder 16 drives the pressurizing plate 15 to move downward, and the pressurizing plate 15 enters the feeding tank 4, and the melt inside the feeding tank 4 is pressed. The melt is pressed downward to promote the melt to flow into the flow limiting mechanism 12. The melt siphon 10 is sealed and connected to the melt siphon through hole 19. The pressure plate 15 is sealed and connected to the inner wall of the feeding tank 4, which can effectively ensure the pressure on the melt. After the melt enters the flow limiting mechanism 12, it passes through a plurality of flow limiting areas 30 and pressure release areas 31 arranged at intervals in sequence. The flow rate of the melt is limited by the flow limiting areas 30 and pressure release areas 31 with shrinking diameters. The melt enters the melt feeding pipe 13. When the melt pressure is greater than the hydraulic pressure above the flow limiting plate above the melt feeding pipe 13, the flow limiting plate can be lifted up to enter the crucible 2. Without changing the crystal growth rate, In this case, the pulling speed of the crystal is corrected, that is, the pulling speed is increased, and the feeding speed of the continuous feeding device is adjusted according to the crystal growth rate. The flow direction of the small amount of melt entering is the same as the flow direction of the melt in the crucible 2, thereby greatly reducing the fluctuation of the melt in the crucible 2 caused by the entering melt, and the quality of the equal-diameter crystals can be maintained. After the melt in the feeding tank 4 is added, due to the reduction of the pressure in the feeding pipe 13, the limiting plate above the melt feeding pipe 13 is reset. Without changing the crystal growth rate, the pulling speed of the crystal is corrected, that is, the pulling speed is reduced. When the crystal weight reaches the specified value, the crystal is pulled off to ensure the stability of the equal-diameter process.

[0026] See also Figure 1 A seed crystal clamp 17 is disposed inside the upper end of the growth furnace shell 1 , a seed crystal 18 is disposed below the seed crystal clamp 17 , and the seed crystal 18 is located above the crucible 2 .

[0027] See also Figure 1A crucible fixing seat 5 is arranged below the crucible 2, a feeding tank fixing seat 8 is arranged below the feeding tank 4, a driving motor 7 is arranged at the middle position below the growth furnace shell 1, a driving rod 6 is transmission-connected above the output end of the driving motor 7, and the driving rod 6 penetrates and extends to the interior of the growth furnace shell 1 and is connected to the crucible fixing seat 5 by a key, a feeding tank support frame 9 is mounted on the outside of the middle position of the driving rod 6, and the feeding tank support frame 9 is fixedly connected to the feeding tank fixing seat 8.

[0028] See also Figure 1 and Figure 6 A first lower heating mechanism 33 is arranged on the outer side of the lower end of the heating mechanism 3, and the first lower heating mechanism 33 is located below the feeding tank fixing seat 8, a second lower heating mechanism 27 is arranged on the inner side of the lower end of the heating mechanism 3, and the second lower heating mechanism 27 is located below the crucible fixing seat 5, and a driving rod groove 14 is opened inside the second lower heating mechanism 27.

[0029] See also Figure 1 and Figure 4 A pressure plate 15 is arranged above the feeding tank 4, and the pressure plate 15 is in a circular ring shape. Two pressure telescopic cylinders 16 are symmetrically arranged above the pressure plate 15. The upper ends of the pressure telescopic cylinders 16 are fixedly connected to the growth furnace shell 1, and the lower ends of the pressure telescopic cylinders 16 are fixedly connected to the pressure plate 15. A pressing through hole 28 is opened at the middle position of the pressure plate 15, and three melt siphon through holes 19 are opened in a ring shape at the outer end of the pressure plate 15, and the melt siphon through holes 19 are adapted to the melt siphon 10.

[0030] See also Figure 1-2 A liquid filling pipe 22 is provided on one side of the upper end of the growth furnace shell 1, and one end of the liquid filling pipe 22 passes through and extends to the interior of the growth furnace shell 1, and a liquid feeding pipe 20 is rotatably connected to the bottom of the liquid filling pipe 22, and a feeding telescopic cylinder 21 is provided below the liquid feeding pipe 20, the upper end of the feeding telescopic cylinder 21 is rotatably connected to the liquid feeding pipe 20, and the lower end of the feeding telescopic cylinder 21 is rotatably connected to the inner wall of the growth furnace shell 1, a sealing cover plate 23 is rotatably provided above the liquid filling pipe 22, and the sealing cover plate 23 is sealed and connected to the liquid filling pipe 22, a sealing cover plate positioning block 24 is provided on one side above the liquid filling pipe 22, a sealing cover plate locking block 25 is provided on one side of the sealing cover plate positioning block 24 and the sealing cover plate 23, and the lower end of the sealing cover plate locking block 25 is slidably connected to the sealing cover plate positioning block 24, and the upper end of the sealing cover plate locking block 25 is located above the sealing cover plate 23.

[0031] See also Figure 1 and Figure 3 A feeding tank 4 has a feeding groove 26 formed inside thereof, and the feeding groove 26 is an annular groove, and the lower end of the liquid feed pipe 20 is located above the feeding groove 26 .

[0032] See also Figure 5 The flow limiting mechanism 12 is located inside the driving rod groove 14, and a flow limiting groove 29 is opened inside the flow limiting mechanism 12. The upper end of the flow limiting groove 29 is sealed with the melt feeding pipe 13, and the lower end of the flow limiting groove 29 is sealed with the conveying pipe 11. The flow limiting groove 29 includes a flow limiting area 30 and a pressure release area 31. The flow limiting area 30 and the pressure release area 31 are spaced apart, and the flow limiting area 30 and the pressure release area 31 are connected. The diameters of the multiple flow limiting areas 30 and the pressure release areas 31 gradually decrease from the conveying pipe 11 to the melt feeding pipe 13.

[0033] Comparing the one-time feeding growth with the continuous feeding growth in the present invention, assuming one-time feeding: about 3kg of feed is added to grow about 1.8kg of crystals, the growth period is about 7 days, of which the heating and cooling time is about 2.5 days, the equal-diameter part is about 1.5kg, and the growth period is about 3.5 days; while the continuous feeding growth of the present invention: about 3kg of feed is added, 2kg of feed is added continuously, the crystal growth is about 3.8kg, the growth period is about 11 days, the estimated heating and cooling time is about 2.5 days, the equal-diameter part is about 3.5kg, and the growth period is about 7.5 days;

[0034] Output of equal diameter parts per unit time: one-time feeding 1.5kg / 7 days = 0.214kg / day; continuous feeding of the present invention 3.5kg / 11 days = 0.318kg / day, the production capacity is increased by about 48%.

[0035] Working principle: When in use, first add the material block into the crucible 2 and the feeding tank 4, close the growth furnace, start the heating mechanism 3, and the high-temperature heating mechanism 3 melts the material block in the crucible 2 and the feeding tank 4.

[0036] Then, the molten melt is slightly cooled to produce supercooling, and then the seed crystal 18 held by the seed crystal clamp 17 is controlled by the crystal rotation and lifting system to be inserted into the melt surface. After the seed crystal 18 is melted with the melt, the seed crystal 18 is slowly pulled upwards, and the seed crystal 18 is rotated at the same time, and the crystal will grow at the lower end of the seed crystal 18; then, the seed crystal is controlled to grow a thin neck with a length of 80 to 120 mm and a diameter of 3 to 5 mm, which is used to eliminate the dislocation of atomic arrangement caused by the strong thermal shock of the high-temperature solution on the seed crystal, so as to achieve seeding; then, the crystal diameter is enlarged to the size required by the process to achieve shoulder release; then, the pulling speed is suddenly increased to perform the shoulder rotation operation, so that the shoulder is approximately right angled, and at the same time, the drive motor 7 is started to drive the drive rod 6 to rotate, and the drive rod 6 drives the crucible 2 and the feeding tank 4 to rotate slowly through the crucible fixing seat 5 and the feeding tank support frame 9, thereby improving the equal diameter effect; then, the equal diameter process is entered, and single crystal columns with the same diameter are grown by controlling the thermal field temperature and the crystal lifting speed;The melt in the feeding tank 4 is fed according to the liquid level of the melt in the crucible 2. The feed liquid is vacuum pumped in advance through the feed liquid feeding pipe 20 and the feed liquid filling pipe 22 according to the time point of feeding. The feed telescopic cylinder 21 is extended to make the feed liquid feeding pipe 20 and the feed liquid filling pipe 22 connect with each other, and the material block is vacuum pumped into the feeding tank 4 through the feed liquid feeding pipe 20 and the feed liquid filling pipe 22. Due to the drive of the driving rod 6, the inputted material is evenly distributed in the inside of the feeding tank 4. When the height of the melt in the feeding tank 4 is higher than the height of the pipe in the melt siphon 10, due to The air pressure difference drives the melt inside the feeding tank 4 to flow to the flow limiting mechanism 12 through the feeding pipe 11, and at the same time, the pressurized telescopic cylinder 16 is extended, and the pressurized telescopic cylinder 16 drives the pressurized plate 15 to move downward, and the pressurized plate 15 enters the feeding tank 4, presses the melt inside the feeding tank 4 downward, and promotes the melt to flow into the flow limiting mechanism 12. The melt siphon 10 is sealed and connected to the melt siphon through hole 19, and the pressurized plate 15 is sealed and connected to the inner wall of the feeding tank 4, which can effectively ensure the pressure on the melt. After the melt enters the flow limiting mechanism 12, it passes through a plurality of flow limiting areas 30 and 30 arranged at intervals in sequence. The pressure relief area 31 limits the flow rate of the melt through the flow limiting area 30 and the pressure relief area 31 with a continuously shrinking diameter. When the melt enters the melt feeding pipe 13 and the melt pressure is greater than the hydraulic pressure above the flow limiting plate above the melt feeding pipe 13, the flow limiting plate can be lifted up to enter the crucible 2. Without changing the crystal growth rate, the pulling speed of the crystal is corrected, that is, the pulling speed is increased. The feeding speed of the continuous feeding device is adjusted according to the crystal growth rate. The flow direction of a small amount of melt entering is the same as the flow direction of the melt in the crucible 2, thereby greatly reducing the impact of the entering melt on the crucible 2. The fluctuations generated by the internal melt can maintain the quality of the equal-diameter crystal. When the melt in the feeding tank 4 is added, the pressure of the feeding pipe 13 is reduced, and the current limiting plate above the melt feeding pipe 13 is reset. Without changing the crystal growth rate, the pulling speed of the crystal is corrected, that is, the pulling speed is reduced. When the crystal weight reaches the specified value, the crystal is pulled off to ensure the stability of the equal-diameter process. Finally, when the melt has completed crystallization, the crystal is gradually reduced to form a tail-shaped cone, which is called the finishing process. In this way, the single crystal pulling process is basically completed and can be taken out after insulation cooling. ;

[0037] It will be apparent to those skilled in the art that the invention is not limited to the details of the exemplary embodiments described above and that the invention can be implemented in other specific forms without departing from the spirit or essential features of the invention. Therefore, the embodiments should be considered exemplary and non-limiting in all respects, and the scope of the invention is defined by the appended claims rather than the foregoing description, and it is intended that all variations falling within the meaning and scope of the equivalent elements of the claims be included in the invention. Any reference numeral in a claim should not be considered as limiting the claim to which it relates.

Claims

1. A continuous feeding system for crystal growth by Czochralski method, comprising a growth furnace housing (1), characterized in that: A heating mechanism (3) is arranged inside the growth furnace shell (1), an upper heating mechanism (32) is arranged at the upper end of the heating mechanism (3), a feeding tank (4) is arranged outside the upper heating mechanism (32), a crucible (2) is arranged inside the upper heating mechanism (32), three melt feeding pipes (13) are arranged in an annular shape at the bottom end of the crucible (2), and the lower ends of the melt feeding pipes (13) penetrate and extend to the outside of the crucible fixing seat (5), three melt siphon pipes (10) are arranged in an annular shape inside the feeding tank (4), the lower ends of the melt siphon pipes (10) are sealedly connected to the feed pipe (11), and one end of the feed pipe (11) is sealedly connected to the bottom of the melt feeding pipe (13) through a flow limiting mechanism (12); A pressure plate (15) is arranged above the feeding tank (4), and the pressure plate (15) is annular. Two pressure telescopic cylinders (16) are symmetrically arranged above the pressure plate (15), the upper ends of the pressure telescopic cylinders (16) are fixedly connected to the growth furnace shell (1), and the lower ends of the pressure telescopic cylinders (16) are fixedly connected to the pressure plate (15). A pressing through hole (28) is provided at the middle position of the pressure plate (15), and three melt siphon through holes (19) are provided in a ring shape at the outer end of the pressure plate (15), and the melt siphon through holes (19) are adapted to the melt siphon (10); The flow limiting mechanism (12) is located inside the driving rod groove (14), and a flow limiting groove (29) is provided inside the flow limiting mechanism (12). The upper end of the flow limiting groove (29) is sealed to the melt feeding pipe (13), and the lower end of the flow limiting groove (29) is sealed to the material delivery pipe (11). The flow limiting groove (29) includes a flow limiting area (30) and a pressure release area (31). The flow limiting area (30) and the pressure release area (31) are arranged at intervals, and the flow limiting area (30) and the pressure release area (31) are connected. The diameters of the plurality of flow limiting areas (30) and the pressure release area (31) gradually decrease from the material delivery pipe (11) to the melt feeding pipe (13).

2. A continuous feeding system for crystal growth by Czochralski method according to claim 1, characterized in that: A seed crystal clamp (17) is arranged inside the upper end of the growth furnace shell (1), a seed crystal (18) is arranged below the seed crystal clamp (17), and the seed crystal (18) is located above the crucible (2).

3. A continuous feeding system for crystal growth by Czochralski method according to claim 1, characterized in that: A crucible fixing seat (5) is arranged below the crucible (2), a charging tank fixing seat (8) is arranged below the charging tank (4), a driving motor (7) is arranged at a middle position below the growth furnace shell (1), a driving rod (6) is connected to the output end of the driving motor (7), and the driving rod (6) passes through and extends into the interior of the growth furnace shell (1) and is connected to the crucible fixing seat (5) via a key, and a charging tank support frame (9) is sleeved on the outside of the middle position of the driving rod (6), and the charging tank support frame (9) is fixedly connected to the charging tank fixing seat (8).

4. A continuous feeding system for crystal pulling growth according to claim 1, characterized in that: A first lower heating mechanism (33) is arranged on the outer side of the lower end of the heating mechanism (3), and the first lower heating mechanism (33) is located below the charging tank fixing seat (8); a second lower heating mechanism (27) is arranged on the inner side of the lower end of the heating mechanism (3), and the second lower heating mechanism (27) is located below the crucible fixing seat (5); and a driving rod groove (14) is provided inside the second lower heating mechanism (27).

5. The continuous feeding system for crystal growth by Czochralski method according to claim 1, characterized in that: A liquid filling pipe (22) is provided on one side of the upper end of the growth furnace shell (1), and one end of the liquid filling pipe (22) penetrates and extends into the interior of the growth furnace shell (1); a liquid feeding pipe (20) is rotatably connected to the lower portion of the liquid filling pipe (22); a feeding telescopic cylinder (21) is provided below the liquid feeding pipe (20); the upper end of the feeding telescopic cylinder (21) is rotatably connected to the liquid feeding pipe (20), and the lower end of the feeding telescopic cylinder (21) is rotatably connected to the inner wall of the growth furnace shell (1).

6. A continuous feeding system for crystal pulling growth according to claim 5, characterized in that: A sealing cover plate (23) is rotatably arranged above the liquid filling tube (22), and the sealing cover plate (23) is sealedly connected to the liquid filling tube (22); a sealing cover plate positioning block (24) is arranged on one side above the liquid filling tube (22); a sealing cover plate locking block (25) is arranged on one side of the sealing cover plate positioning block (24) and the sealing cover plate (23); the lower end of the sealing cover plate locking block (25) is slidably connected to the sealing cover plate positioning block (24), and the upper end of the sealing cover plate locking block (25) is located above the sealing cover plate (23).

7. A continuous feeding system for crystal pulling growth according to claim 5, characterized in that: The feeding tank (4) is provided with a feeding groove (26) in the form of an annular groove, and the lower end of the liquid feed pipe (20) is located above the feeding groove (26).

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