Monocrystalline silicon automatic doping delayed adding device and delayed adding method

Abstract

The invention relates to the technical field of photovoltaic processing, in particular to a monocrystalline silicon automatic doping delayed adding device and a delayed adding method.The monocrystalline silicon automatic doping delayed adding device comprises a mounting pipe, a rotary telescopic mechanism is arranged in the mounting pipe and comprises a driving pipe and a telescopic rotating rod, a doping spoon is arranged at one end of the telescopic rotating rod, a containing groove is formed in the doping spoon, and the driving pipe is connected with the containing groove; the outer wall of the doping spoon is provided with a V-shaped notch for the doped material to fall out, the interior of the containing groove is provided with a vertical separation blade which uniformly divides the containing groove into two half cavities, and a limiting mechanism which limits the rotation of the separation blade and enables the separation blade to translate along with the doping spoon is arranged between the separation blade and the mounting pipe. In the rotating process of the doping spoon, the doping materials in the two half cavities fall out through the V-shaped notches in stages, delayed adding of the doping materials is achieved, the defect that the local concentration is too high is overcome, and the doping materials are more evenly distributed in silicon liquid.

Description

Technical Field

[0001] This invention relates to the field of photovoltaic processing technology, specifically to an automatic delayed doping device and method for monocrystalline silicon. Background Technology

[0002] Monocrystalline silicon is generally produced using the Czochralski method, a process that involves melting polycrystalline silicon and gradually pulling it up using a seed crystal to create monocrystalline silicon. The basic principle is to place high-purity polycrystalline silicon raw material into a quartz crucible and heat it to melt in an inert gas environment. Then, a rotating seed crystal is immersed in the molten silicon. By controlling the temperature gradient, pulling rate, and rotation speed, the molten silicon is oriented and solidified on the seed crystal to form a monocrystalline silicon ingot, which is then cut into silicon wafers for use.

[0003] In the production of monocrystalline silicon, doping is required to introduce specific impurity atoms to change the electrical properties of monocrystalline silicon. However, existing doping processes have the following drawbacks: Traditional doping spoons are boat-shaped containers. When the spoon is tilted to pour the dopant, it is easy for all the dopant to be poured into the single crystal furnace at once. This concentrated dopant will form localized high-concentration areas in the silicon melt. Since the diffusion of impurities in the melt takes time, it is difficult to achieve uniform distribution in a short period of time. This leads to large differences in impurity concentration at different locations in the melt, resulting in large deviations in the radial resistivity of the grown single crystal silicon. Furthermore, as the crystal grows, the impurity concentration in the melt will continue to fluctuate due to the uneven initial distribution, eventually causing abrupt changes or abnormal gradients in the axial resistivity of the single crystal rod. Summary of the Invention

[0004] Therefore, it is necessary to provide an automatic delayed doping device and method for monocrystalline silicon to address the problems of existing technologies.

[0005] To address the problems of existing technologies, the present invention adopts the following technical solution: an automatic delayed doping device for monocrystalline silicon, comprising a horizontally arranged mounting tube, a rotary telescopic mechanism within the mounting tube, the rotary telescopic mechanism comprising a drive tube and a telescopic rotating rod connected by transmission, the drive tube being coaxially disposed within the mounting tube, and the telescopic rotating rod being coaxially disposed within the drive tube, the drive tube being used to drive the telescopic rotating rod to extend, retract, and rotate, one end of the telescopic rotating rod being provided with a doping spoon extending out of the mounting tube, the doping spoon being provided with a receiving groove for holding dopants, the outer wall of the doping spoon being provided with a V-shaped groove for the dopants to fall out, the receiving groove being provided with a vertically aligned baffle that is evenly divided into two semi-cavities, and a limiting mechanism being provided between the baffle and the mounting tube to restrict the rotation of the baffle and enable the baffle to move translatably with the doping spoon.

[0006] To demonstrate how the drive tube drives the telescopic rod to extend and retract, a vertically downward protrusion is fixed on the outer wall of the drive tube. A vertically slidable pin is provided inside the protrusion. A push-pull electromagnet for driving the pin to slide up and down is connected to the protrusion. Two slots are provided on the outer wall of the telescopic rod, spaced apart along its axial direction. The extension direction of each slot is perpendicular to the axial direction of the telescopic rod. The pin can be inserted into each slot.

[0007] To demonstrate how the drive tube drives the telescopic rod to rotate, a spiral groove extending axially is formed on the outer wall of the telescopic rod. A limiting pin is fixed on the outer wall of the drive tube and inserted directly into the spiral groove. One end of the mounting tube is coaxially connected to a limiting tube. A retaining ring is provided at the end of the limiting tube away from the mounting tube. A convex ring is provided on the outer wall of the telescopic rod between the retaining ring and the end of the mounting tube. A stop block is formed on the convex ring that can press against the retaining ring and the end of the mounting tube. A connecting tube is coaxially fixed to the end of the telescopic rod near the limiting tube. The doping spoon is connected to the connecting tube.

[0008] To demonstrate how the doping spoon is connected to the telescopic rotating rod, one end of the connecting tube is formed with a threaded interface, and the outer wall of the doping spoon is formed with a threaded sleeve screwed onto the threaded interface.

[0009] To illustrate the specific structure of the limiting mechanism, the limiting mechanism includes a connecting rod and an L-shaped limiting rod. Several bearings evenly distributed along its axial direction are fixed inside the connecting tube. The connecting rod passes through several bearings in sequence, and the inner ring of each bearing is fixedly connected to the connecting rod. One end of the connecting rod passes through a threaded interface and is fixedly connected to a baffle in the mounting groove. The vertical end of the L-shaped limiting rod is fixedly connected to the other end of the connecting rod. A limiting sleeve is fixedly provided on the outer wall of the connecting tube. The horizontal end of the L-shaped limiting rod passes coaxially through the limiting sleeve. An avoidance groove is provided on the connecting tube to avoid the L-shaped limiting rod.

[0010] To ensure that the telescopic rod can move stably along its axial direction during extension and retraction, two strip-shaped grooves symmetrical about its axis are provided on the inner wall of the limiting tube. Each strip-shaped groove is located between the end of the retaining ring and the mounting tube, and the length direction of each strip-shaped groove is parallel to the axial direction of the limiting tube. Each strip-shaped groove can allow the abutment block to slide.

[0011] In order to ensure that the opening of the mixing spoon faces upward precisely when it rotates and resets, a first limiting block is fixedly provided inside the end of the limiting tube near the mounting tube. This first limiting block restricts the rotation stroke of the telescopic rod by abutting against the abutment block.

[0012] In order to ensure that the opening of the mixing spoon faces downwards precisely when it rotates to pour material, a second limiting block is fixedly installed at the end of the limiting tube away from the mounting tube. This limiting block restricts the rotation stroke of the telescopic rod by abutting against the stop block.

[0013] To facilitate the fixing of the installation tube, vertically upward connecting seats are fixed on the outer walls of both the limiting tube and the installation tube.

[0014] A method for automatically and delayedly adding dopant to single-crystal silicon, the method comprising the following steps: S1, In the initial state, the drive tube drives the doping spoon to be in a retracted state through the telescopic rotating rod. At this time, the doping spoon is located outside the single crystal furnace and the baffle is vertical. Doping material is filled into the doping spoon and the doping material falls into the two half-cavities of the receiving tank through the baffle. S2, the drive tube drives the telescopic rotating rod to move horizontally toward the single crystal furnace. During this process, the doping spoon is pushed into the single crystal furnace with its opening facing upward. At the same time, the baffle moves horizontally along with the doping spoon through the connection between the connecting rod and the bearing. S3, when the doping spoon reaches directly above the silicon liquid in the furnace, the drive tube continues to move horizontally. At this time, the telescopic rotating rod cannot move axially because the block and the retaining ring are in contact. The limiting pin slides in the spiral groove, driving the telescopic rotating rod to rotate. The doping spoon rotates with the telescopic rotating rod, and its opening gradually flips downward. S4. As the doping spoon rotates, the dopant in one half of the cavity falls into the molten silicon through the V-shaped groove, while the dopant in the other half of the cavity is blocked by the baffle that is always kept vertical, thus achieving delayed addition of the dopant. S5, when the doping spoon rotates more than 90°, the doping material in the other half of the cavity falls out along the V-shaped groove. When the doping spoon rotates 180°, all the doping material in both half of the cavity falls out. S6, the drive tube drives the telescopic rotating rod to retract. After the doping spoon retracts outside the single crystal furnace, the drive tube drives the telescopic rotating rod to rotate in the opposite direction until it is reset. The opening of the doping spoon faces upward again, completing one doping delay addition process.

[0015] The beneficial effects of this invention compared to the prior art are: Firstly, this device divides the receiving tank into two semi-cavities by a baffle. During the rotation of the doping spoon, the dopant in the two semi-cavities falls out through the V-shaped groove in stages, realizing the delayed addition of dopant, avoiding the defect of excessive local concentration, and making the dopant more evenly distributed in the silicon liquid. Secondly, this device can achieve the staged addition of dopants. In the first stage, a portion of dopants is added. Under the stirring action of the silicon liquid, this portion of dopants can fully react with the silicon liquid. After the doping spoon is rotated more than 90°, another portion of dopants is added, so that the dopants added later can also be fully integrated in the silicon liquid that has already reacted relatively evenly. Compared with the traditional method, the reaction sufficiency is greatly improved. Thirdly, in this device, the rotation angle of the telescopic rotating rod driven by the drive tube can be precisely controlled. By controlling the rotation process of the doping spoon, the timing and amount of dopant added in the two half-cavities can be precisely controlled, realizing the precise controllability of the doping process and overcoming the defects of poor controllability in traditional methods. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the three-dimensional structure of the present invention during the retraction of the doping spoon. Figure 1 ; Figure 2 This is a schematic diagram of the three-dimensional structure of the present invention during the retraction of the doping spoon. Figure 2 ; Figure 3 yes Figure 2 A magnified view of the area indicated by A1 in the diagram; Figure 4 This is a three-dimensional cross-sectional view of the present invention during the retraction of the doping spoon. Figure 1 ; Figure 5 yes Figure 4 The enlarged view of the area indicated by A2 in the diagram; Figure 6 yes Figure 4 The enlarged view of the area indicated in A3; Figure 7 yes Figure 4 The enlarged view shown in section A4; Figure 8 This is a three-dimensional cross-sectional view of the present invention during the retraction of the doping spoon. Figure 2 ; Figure 9 This is a three-dimensional cross-sectional view of the present invention when the doping spoon is extended; Figure 10 This is a three-dimensional cross-sectional view of the present invention after the doping spoon has been rotated 180°; Figure 11 This is a three-dimensional structural diagram of the abutment block and the first limiting block in abutment engagement; Figure 12 This is a three-dimensional structural diagram of the abutment block and the second limiting block in abutment and engagement. Figure 13 This is a three-dimensional structural diagram of the telescopic boom; Figure 14 This is a planar cross-sectional view of the mixing spoon after it has been rotated 90°.

[0017] The following are the labels in the diagram: 1. Mounting pipe; 2. Drive pipe; 3. Telescopic rotating rod; 4. Mixing spoon; 5. Container groove; 6. V-shaped groove; 7. Baffle; 8. Boss; 9. Pin; 10. Push-pull electromagnet; 11. Slot; 12. Spiral groove; 13. Limiting pin; 14. Limiting pipe; 15. Retaining ring; 16. Protruding ring; 17. Abutment; 18. Connecting pipe; 19. Threaded interface; 20. Threaded sleeve; 21. Connecting rod; 22. L-shaped limiting rod; 23. Bearing; 24. Limiting sleeve; 25. Clearance groove; 26. Strip groove; 27. Limiting block No. 1; 28. Limiting block No. 2; 29. ​​Connecting seat; 30. Rotary telescopic mechanism; 31. Limiting mechanism. Detailed Implementation

[0018] To further understand the features, technical means, and specific objectives and functions achieved by the present invention, the present invention will be described in further detail below with reference to the accompanying drawings and specific embodiments.

[0019] refer to Figure 1 , Figure 4 and Figure 7 The device for automatic delayed doping of single-crystal silicon includes a horizontally arranged mounting tube 1. A rotary telescopic mechanism 30 is installed inside the mounting tube 1. The rotary telescopic mechanism 30 includes a drive tube 2 and a telescopic rotating rod 3 connected by a transmission. The drive tube 2 is coaxially arranged inside the mounting tube 1, and the telescopic rotating rod 3 is coaxially arranged inside the drive tube 2. The drive tube 2 is used to drive the telescopic rotating rod 3 to extend, retract, and rotate. One end of the telescopic rotating rod 3 is provided with a doping spoon 4 extending out of the mounting tube 1. The doping spoon 4 has a receiving groove 5 for holding dopants. A V-shaped groove 6 is opened on the outer wall of the doping spoon 4 for the dopants to fall out. A vertically aligned baffle 7 is provided in the receiving groove 5, which is evenly divided into two semi-cavities. A limiting mechanism 31 is provided between the baffle 7 and the mounting tube 1 to restrict the rotation of the baffle 7 and allow the baffle 7 to move translatably with the doping spoon 4.

[0020] This device is used to gradually add dopants to molten silicon during the Czochralski process for producing single-crystal silicon. The mounting tube 1 of this device is fixed to the outer wall of the single-crystal furnace. Initially, as... Figure 1As shown, the opening of the doping spoon 4 faces upward, and the baffle 7 is vertical. When dopant needs to be added to the single crystal furnace, dopant is first loaded into the doping spoon 4. The dopant will fall into the two half-cavities of the receiving tank 5. Then, the drive tube 2 starts to drive the telescopic rotating rod 3 to move horizontally towards the single crystal furnace. During this process, the doping spoon 4 will be pushed into the single crystal furnace with its opening facing upward by the telescopic rotating rod 3. When the doping spoon 4 reaches directly above the silicon liquid in the furnace, the drive tube 2 will drive the telescopic rotating rod 3 to rotate. As the telescopic rotating rod 3 rotates, the opening of the doping spoon 4 gradually flips downward. During the process, the dopant located in one half of the cavity falls into the molten silicon below through the V-shaped groove 6. In actual operation, the single crystal furnace is equipped with a stirring device (not shown in the figure) for stirring the surface of the molten silicon. The stirring device keeps the surface of the molten silicon in a rotating state, so that the dopant falling into the molten silicon will form a ring around the crystal rod, making the dopant evenly distributed. As the doping spoon 4 rotates, the dopant in the other half of the cavity is blocked by the baffle 7, thus preventing all the dopant in the receiving tank 5 from falling out. When the doping spoon 4 rotates to more than 90°, as... Figure 14 As shown, the dopant in the other half of the cavity will fall out along the V-shaped groove 6. When the dopant spoon 4 rotates 180°, all the dopant in both half of the cavity will fall out. After that, the drive tube 2 will drive the dopant spoon 4 to retract through the telescopic rotating rod 3. When the dopant spoon 4 retracts outside the single crystal furnace, the drive tube 2 will start to drive the telescopic rotating rod 3 to rotate in the opposite direction until it is reset. During this process, the opening of the dopant spoon 4 will gradually flip upward, and finally the opening of the dopant spoon 4 will face upward again. In actual operation, a linear cylinder (not shown in the figure) is installed on the side of the drive tube 2. The linear cylinder drives the drive tube 2 to slide in both directions.

[0021] refer to Figure 4 , Figure 5 and Figure 13 As shown, a vertically downward boss 8 is fixed on the outer wall of the drive tube 2. A vertically oriented pin 9 is slidably provided inside the boss 8. A push-pull electromagnet 10 for driving the pin 9 to slide up and down is connected to the boss 8. Two slots 11 are provided on the outer wall of the telescopic rotating rod 3, which are spaced apart along its axial direction. The extension direction of each slot 11 is perpendicular to the axial direction of the telescopic rotating rod 3. The pin 9 can be inserted into each slot 11.

[0022] When the push-pull electromagnet 10 is energized, the pin 9 is driven to slide downwards. When the push-pull electromagnet 10 is de-energized, the pin 9 is driven to slide upwards. When the drive tube 2 needs to move the telescopic rotating rod 3 towards the single crystal furnace, the push-pull electromagnet 10 is de-energized, and the pin 9 will insert upwards into the corresponding slot 11. Thus, during the process of the drive tube 2 moving towards the single crystal furnace, the drive tube 2 will drive the telescopic rotating rod 3 to move along with it via the pin 9. When the telescopic rotating rod 3 drives the doping spoon 4 to the designated position inside the furnace, the push-pull electromagnet 10 is energized. At this time, the pin 9 will slide downwards and separate from the corresponding slot 11. After the pin 9 separates from the slot 11, it rotates with the telescopic rotating rod 3. The connected drive tube 2 will drive the telescopic rotating rod 3 to rotate by translation. During the process of the telescopic rotating rod 3 driving the doping spoon 4 to rotate 180°, the positions of the two slots 11 will be reversed. When the drive tube 2 needs to drive the telescopic rotating rod 3 to retract, the push-pull electromagnet 10 will be de-energized. At this time, the pin 9 will be inserted upward into the slot 11 that was originally located above. Finally, the drive tube 2 will drive the telescopic rotating rod 3 to slide in the opposite direction until it is reset through the pin 9. During the processing of the boss 8, the boss 8 is close to the end of the drive tube 2 that is away from the single crystal furnace. In this way, when the push-pull electromagnet 10 is installed on the boss 8, the push-pull electromagnet 10 will not enter the single crystal furnace, preventing the high temperature inside the furnace from affecting the magnetism of the push-pull electromagnet 10.

[0023] refer to Figure 4 , Figure 6 , Figure 7 and Figure 8 As shown, a spiral groove 12 extending axially is provided on the outer wall of the telescopic rotating rod 3. A limiting pin 13 is fixedly provided on the outer wall of the drive tube 2 and inserted directly into the spiral groove 12. One end of the mounting tube 1 is coaxially connected to a limiting tube 14. A retaining ring 15 is provided in the end of the limiting tube 14 away from the mounting tube 1. A convex ring 16 is provided on the outer wall of the telescopic rotating rod 3 between the retaining ring 15 and the end of the mounting tube 1. A stop block 17 is formed on the convex ring 16 that can press against the end of the retaining ring 15 and the end of the mounting tube 1. A connecting tube 18 is coaxially fixed to the end of the telescopic rotating rod 3 near the limiting tube 14. The mixing spoon 4 is connected to the connecting tube 18.

[0024] When the drive tube 2 moves the telescopic rotating rod 3 towards the single crystal furnace via the pin 9, the convex ring 16 will drive the abutment 17 to move from the end of the mounting tube 1 towards the retaining ring 15. When the doping spoon 4 reaches the designated position, the abutment 17 abuts against the retaining ring 15, and at this time the pin 9 separates from the corresponding slot 11. Afterward, the drive tube 2 will continue to move towards the single crystal furnace. During this process, the telescopic rotating rod 3 cannot make axial displacement due to the cooperation between the abutment 17 and the retaining ring 15. Then the limiting pin 13 will slide in the spiral groove 12 following the translation of the drive tube 2. At this time, through the abutment of the limiting pin 13, the entire telescopic rotating rod 3 will be driven to rotate. After the telescopic rotating rod 3 rotates the doping spoon 4 180°, the pin 9 is inserted upward into another slot 11. Then, the drive tube 2 drives the telescopic rotating rod 3 to slide in the opposite direction to reset. During this process, the convex ring 16 will drive the abutment 17 to move towards the end of the mounting tube 1. When the doping spoon 4 slides in the opposite direction to reset, the abutment 17 abuts against the end of the mounting tube 1. At this time, the pin 9 separates from the corresponding slot 11. The drive tube 2 continues to slide in the opposite direction. During this process, the limit pin 13 will abut against the spiral groove 12 again and slide in the spiral groove 12. In this way, the entire telescopic rotating rod 3 will be driven to rotate in the opposite direction until the opening of the doping spoon 4 faces upward.

[0025] refer to Figure 4 and Figure 7 As shown, one end of the connecting tube 18 is formed with a threaded interface 19, and the outer wall of the mixing spoon 4 is formed with a threaded sleeve 20 screwed onto the threaded interface 19.

[0026] When connecting the doping spoon 4 to the telescopic rotating rod 3, first fix the connecting pipe 18 to the end of the telescopic rotating rod 3 near the limiting pipe 14, and then screw the threaded sleeve 20 onto the threaded interface 19 to finally fix the doping spoon 4.

[0027] refer to Figure 7 As shown, the limiting mechanism 31 includes a connecting rod 21 and an L-shaped limiting rod 22. Several bearings 23 are fixedly installed inside the connecting pipe 18 and are evenly distributed along its axial direction. The connecting rod 21 passes through several bearings 23 in sequence, and the inner ring of each bearing 23 is fixedly connected to the connecting rod 21. One end of the connecting rod 21 passes through the threaded interface 19 and is fixedly connected to the baffle 7 in the mounting groove 5. The vertical end of the L-shaped limiting rod 22 is fixedly connected to the other end of the connecting rod 21. A limiting sleeve 24 is fixedly installed on the outer wall of the connecting pipe 18. The horizontal end of the L-shaped limiting rod 22 passes through the limiting sleeve 24 coaxially. A clearance groove 25 is opened on the connecting pipe 18 to avoid the L-shaped limiting rod 22.

[0028] When the drive tube 2 drives the telescopic rotating rod 3 to extend or retract, the telescopic rotating rod 3 will move the doping spoon 4 horizontally through the connecting tube 18. During this process, the baffle 7 will move horizontally along with the doping spoon 4 through the connection between the connecting rod 21 and the bearing 23. At the same time, the horizontal end of the L-shaped limiting rod 22 will slide within the limiting sleeve 24. When the drive tube 2 drives the telescopic rotating rod 3 to rotate, the doping spoon 4 will rotate along with the telescopic rotating rod 3. During this process, the baffle 7 will remain vertical because its rotation is restricted by the L-shaped limiting rod 22 passing through the limiting sleeve 24. Ultimately, the baffle 7 will block the doping material in one half of the cavity by preventing it from rotating. When processing the baffle 7, the shape of the baffle 7 is as follows: Figure 10 As shown, when the mixing spoon 4 rotates, the baffle 7 will not interfere with the receiving groove 5.

[0029] refer to Figure 6 and Figure 7 As shown, two strip-shaped grooves 26 are provided on the inner wall of the limiting tube 14, which are symmetrical about their axis. Each strip-shaped groove 26 is located between the end of the retaining ring 15 and the mounting tube 1, and the length direction of each strip-shaped groove 26 is parallel to the axis of the limiting tube 14. Each strip-shaped groove 26 can allow the abutment block 17 to slide.

[0030] During the process of the telescopic rotating rod 3 sliding from the retracted state to the extended state, the abutment 17 will slide within the upper strip groove 26. During the process of the telescopic rotating rod 3 sliding from the extended state to the retracted state, the abutment 17 will slide within the lower strip groove 26. In summary, the cooperation between the abutment 17 and the strip groove 26 ensures that the telescopic rotating rod 3 will not rotate during translation.

[0031] refer to Figure 11 As shown, a first limiting block 27 is fixedly provided inside the end of the limiting tube 14 near the mounting tube 1, which limits the rotation stroke of the telescopic rod 3 by abutting against the abutment block 17.

[0032] The rotation stroke of the telescopic rotating rod 3 is limited by the contact between the first limiting block 27 and the stop block 17, ensuring that the opening of the mixing spoon 4 can be accurately facing upward when it rotates and resets.

[0033] refer to Figure 12 As shown, a second limiting block 28 is fixedly provided at the end of the limiting tube 14 away from the mounting tube 1. This limiting block 28 restricts the rotation stroke of the telescopic rod 3 by abutting against the abutment block 17.

[0034] The rotation stroke of the telescopic rotating rod 3 is limited by the contact between the second limiting block 28 and the abutment block 17, ensuring that the opening of the mixing spoon 4 can face downwards precisely when it rotates to pour materials.

[0035] refer to Figure 1As shown, both the limiting tube 14 and the mounting tube 1 are fixed with vertically upward connecting seats 29.

[0036] During actual installation, a horizontally extending support rod (not shown in the figure) is connected to the outer wall of the single crystal furnace. Both the mounting tube 1 and the limiting tube 14 are fixed to the support rod through the connecting seat 29.

[0037] 10. A method for automatically adding delayed doping to single-crystal silicon, using the device for automatically adding delayed doping to single-crystal silicon as described in claim 5, characterized in that the method comprises the following steps: S1, In the initial state, the drive tube 2 drives the doping spoon 4 to be in a retracted state through the telescopic rotating rod 3. At this time, the doping spoon 4 is located outside the single crystal furnace, and the baffle 7 is vertical. Doping material is filled into the doping spoon 4, and the doping material falls into the two half-cavities of the receiving groove 5 through the baffle 7. This device is used to gradually add dopants to the silicon liquid during the production of single crystal silicon using the Czochralski method. When the dopants fall into the receiving tank 5, the baffles 7 are used to make the dopants evenly dispersed in the two half-cavities.

[0038] S2, the drive tube 2 drives the telescopic rotating rod 3 to move horizontally toward the single crystal furnace. During this process, the doping spoon 4 is pushed into the single crystal furnace with its opening facing upward. At the same time, the baffle 7 moves horizontally along with the doping spoon 4 through the connection between the connecting rod 21 and the bearing 23. When the drive tube 2 needs to move the telescopic rotating rod 3 towards the single crystal furnace, the push-pull electromagnet 10 is de-energized, and the pin 9 will be inserted upward into the corresponding slot 11. Thus, during the process of the drive tube 2 moving towards the single crystal furnace, the drive tube 2 will move the telescopic rotating rod 3 along with it through the pin 9, and finally the doping spoon 4 will be inserted into the single crystal furnace.

[0039] S3, when the doping spoon 4 reaches directly above the silicon liquid in the furnace, the drive tube 2 continues to move horizontally. At this time, the telescopic rotating rod 3 cannot move axially because the block 17 and the retaining ring 15 are in contact. The limiting pin 13 slides in the spiral groove 12, which drives the telescopic rotating rod 3 to rotate. The doping spoon 4 rotates with the telescopic rotating rod 3, and its opening gradually flips downward. When the telescopic rotating rod 3 drives the doping spoon 4 to extend into the designated position inside the furnace, the push-pull electromagnet 10 is energized. At this time, the pin 9 will slide down and separate from the corresponding slot 11. After the pin 9 separates from the slot 11, the drive tube 2 will continue to move towards the single crystal furnace. During this process, the telescopic rotating rod 3 cannot make axial displacement through the cooperation of the stop block 17 and the retaining ring 15. Then the limiting pin 13 will slide in the spiral groove 12 following the translation of the drive tube 2. At this time, the entire telescopic rotating rod 3 will be driven to rotate by the abutment of the limiting pin 13.

[0040] S4. As the doping spoon 4 rotates, the dopant in one half of the cavity falls into the molten silicon through the V-shaped groove 6, while the dopant in the other half of the cavity is blocked by the baffle 7, which is always kept vertical, thus achieving delayed addition of the dopant. In actual operation, the single crystal furnace is equipped with a stirring device (not shown in the figure) for stirring the surface of the silicon liquid. The stirring device keeps the surface of the silicon liquid in a rotating state, so that the dopants falling into the silicon liquid will surround the crystal rod in a ring, making the dopants evenly distributed. During the rotation of the doping spoon 4, the dopants in the other half of the cavity will be blocked by the baffle 7, thereby preventing all the dopants in the receiving tank 5 from falling out.

[0041] S5, when the doping spoon 4 rotates more than 90°, the doping material in the other half of the cavity falls out along the V-shaped groove 6 one after another. When the doping spoon 4 rotates 180°, all the doping material in both half of the cavity falls out. When the mixing spoon 4 is rotated to more than 90°, as Figure 14 As shown, the dopant in the other half of the cavity will fall out one after another along the V-shaped groove 6. When the doping spoon 4 rotates 180°, all the dopant in both half of the cavity will fall out.

[0042] S6, the drive tube 2 drives the telescopic rotating rod 3 to retract. When the doping spoon 4 retracts outside the single crystal furnace, the drive tube 2 drives the telescopic rotating rod 3 to rotate in the opposite direction until it is reset. The opening of the doping spoon 4 faces upward again, completing one doping delay addition process.

[0043] After doping is complete, the drive tube 2 will retract the doping spoon 4 via the telescopic rotating rod 3. Once the doping spoon 4 has retracted outside the single crystal furnace, the drive tube 2 will start to drive the telescopic rotating rod 3 to rotate in the opposite direction until it is reset. During this process, the opening of the doping spoon 4 will gradually flip upward, and eventually the opening of the doping spoon 4 will face upward again. In actual operation, a linear cylinder (not shown in the figure) is installed on the side of the drive tube 2, and the linear cylinder is used to drive the drive tube 2 to slide in both directions.

[0044] The above embodiments only illustrate one or more implementations of the present invention, and their descriptions are relatively specific and detailed, but they should not be construed as limiting the scope of the present invention. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these all fall within the protection scope of the present invention. Therefore, the protection scope of this patent should be determined by the appended claims.

Claims

1. An automatic delayed doping device for single-crystal silicon, characterized in that, The device includes a horizontally arranged installation tube (1), which is equipped with a rotating telescopic mechanism (30). The rotating telescopic mechanism (30) includes a drive tube (2) and a telescopic rotating rod (3) connected by a transmission. The drive tube (2) is coaxially arranged inside the installation tube (1), and the telescopic rotating rod (3) is coaxially arranged inside the drive tube (2). The drive tube (2) is used to drive the telescopic rotating rod (3) to extend and rotate. One end of the telescopic rotating rod (3) is provided with a doping spoon (4) extending out of the installation tube (1). The doping spoon (4) is provided with a receiving groove (5) for holding doping material. The outer wall of the doping spoon (4) is provided with a V-shaped groove (6) for the doping material to fall out. The receiving groove (5) is provided with a vertically arranged baffle (7) that is evenly divided into two half-cavities. A limiting mechanism (31) is provided between the baffle (7) and the installation tube (1) to restrict the rotation of the baffle (7) and enable the baffle (7) to move with the doping spoon (4).

2. The automatic delayed doping device for single-crystal silicon according to claim 1, characterized in that, A vertically downward boss (8) is fixed on the outer wall of the drive tube (2). A vertically oriented pin (9) is slidably provided inside the boss (8). A push-pull electromagnet (10) for driving the pin (9) to slide up and down is connected to the boss (8). Two slots (11) are provided on the outer wall of the telescopic rotating rod (3) and are spaced apart along its axial direction. The extension direction of each slot (11) is perpendicular to the axial direction of the telescopic rotating rod (3). The pin (9) can be inserted into each slot (11).

3. The automatic delayed doping device for single-crystal silicon according to claim 1, characterized in that, A spiral groove (12) extending along its axial direction is provided on the outer wall of the telescopic rotating rod (3). A limiting pin (13) is fixedly inserted into the spiral groove (12) on the outer wall of the drive tube (2). A limiting tube (14) is coaxially connected to one end of the mounting tube (1). A retaining ring (15) is provided in the end of the limiting tube (14) away from the mounting tube (1). A convex ring (16) is provided on the outer wall of the telescopic rotating rod (3) between the retaining ring (15) and the end of the mounting tube (1). A stop block (17) is formed on the convex ring (16) that can press against the end of the retaining ring (15) and the end of the mounting tube (1). A connecting tube (18) is coaxially fixed to the end of the telescopic rotating rod (3) near the limiting tube (14). The doping spoon (4) is connected to the connecting tube (18).

4. The automatic delayed doping device for single-crystal silicon according to claim 3, characterized in that, One end of the connecting tube (18) is formed with a threaded interface (19), and the outer wall of the mixing spoon (4) is formed with a threaded sleeve (20) screwed onto the threaded interface (19).

5. The automatic delayed doping device for single-crystal silicon according to claim 4, characterized in that, The limiting mechanism (31) includes a connecting rod (21) and an L-shaped limiting rod (22). Several bearings (23) are fixedly arranged in the connecting tube (18) and evenly distributed along its axial direction. The connecting rod (21) passes through several bearings (23) in sequence, and the inner ring of each bearing (23) is fixedly connected to the connecting rod (21). One end of the connecting rod (21) passes through the threaded interface (19) and is fixedly connected to the baffle (7) in the mounting groove (5). The vertical end of the L-shaped limiting rod (22) is fixedly connected to the other end of the connecting rod (21). A limiting sleeve (24) is fixedly provided on the outer wall of the connecting tube (18). The horizontal end of the L-shaped limiting rod (22) passes through the limiting sleeve (24) coaxially. A clearance groove (25) is provided on the connecting tube (18) to avoid the L-shaped limiting rod (22).

6. The automatic delayed doping device for single-crystal silicon according to claim 3, characterized in that, The inner wall of the limiting tube (14) has two strip grooves (26) that are symmetrical about their axis. Each strip groove (26) is located between the end of the retaining ring (15) and the mounting tube (1), and the length direction of each strip groove (26) is parallel to the axis of the limiting tube (14). Each strip groove (26) can be used for the abutment block (17) to slide.

7. The automatic delayed doping device for single-crystal silicon according to claim 3, characterized in that, The limiting tube (14) is fixedly provided with a first limiting block (27) at one end near the mounting tube (1) to limit the rotation stroke of the telescopic rod (3) by abutting against the abutment block (17).

8. The automatic delayed doping device for single-crystal silicon according to claim 3, characterized in that, The limiting tube (14) is fixedly provided with a second limiting block (28) at the end away from the installation tube (1), which limits the rotation stroke of the telescopic rod (3) by abutting against the abutment block (17).

9. The automatic delayed doping device for single-crystal silicon according to claim 3, characterized in that, The outer walls of both the limiting tube (14) and the mounting tube (1) are fixed with vertically upward connecting seats (29).

10. A method for automatically adding delayed doping to single-crystal silicon, using the automatic doping delayed doping device for single-crystal silicon as described in claim 5, characterized in that... The method includes the following steps: S1, In the initial state, the drive tube (2) drives the doping spoon (4) to be in a retracted state through the telescopic rotating rod (3). At this time, the doping spoon (4) is located outside the single crystal furnace, and the baffle (7) is vertical. Doping material is filled into the doping spoon (4), and the doping material falls into the two half-cavities of the receiving groove (5) through the baffle (7). S2, the drive tube (2) drives the telescopic rotating rod (3) to move towards the single crystal furnace. During this process, the doping spoon (4) is pushed into the single crystal furnace with its opening facing upward. At the same time, the baffle (7) moves along with the doping spoon (4) through the connection between the connecting rod (21) and the bearing (23). S3, when the doping spoon (4) reaches directly above the silicon liquid in the furnace, the drive tube (2) continues to move horizontally. At this time, the telescopic rotating rod (3) cannot move axially because the block (17) and the retaining ring (15) are in contact. The limiting pin (13) slides in the spiral groove (12), which drives the telescopic rotating rod (3) to rotate. The doping spoon (4) rotates with the telescopic rotating rod (3), and its opening gradually flips downward. S4, as the doping spoon (4) rotates, the dopant in one half of the cavity falls into the silicon liquid through the V-shaped groove (6), while the dopant in the other half of the cavity is blocked by the baffle (7) that is always vertical, thus achieving delayed addition of the dopant. S5, when the doping spoon (4) rotates more than 90°, the doping material in the other half cavity falls out along the V-shaped groove (6) one after another. When the doping spoon (4) rotates 180°, all the doping material in both half cavities falls out. S6, the drive tube (2) drives the telescopic rotating rod (3) to retract. When the doping spoon (4) retracts to outside the single crystal furnace, the drive tube (2) drives the telescopic rotating rod (3) to rotate in the opposite direction until it is reset. The opening of the doping spoon (4) faces upward again, completing one doping delay addition process.

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