Continuous feeding device for silicon single crystal growth and single crystal furnace adopting same

Abstract

The invention relates to the field of single crystal silicon rod production equipment, in particular to a continuous feeding device for silicon single crystal growth and a single crystal furnace adopting the device. On one hand, the invention relates to a continuous feeding device for silicon single crystal growth. The continuous feeding device comprises a feeding cylinder, a lifting mechanism arranged on the feeding cylinder, a clamping mechanism and a sealing mechanism, and the feeding cylinder is connected with the single crystal furnace and is communicated with the single crystal furnace. On the other hand, the invention relates to a single crystal furnace which comprises a main furnace body, an auxiliary furnace body and a silicon single crystal growth continuous feeding device, the auxiliary furnace body and the feeding cylinder are both arranged above the main furnace body. And the feeding cylinder and the auxiliary furnace body are arranged in parallel. When materials are fed into the single crystal furnace, a polycrystalline silicon charge bar is hoisted in the feeding cylinder through the clamping mechanism, then the spin valve is opened, and the lifting mechanism controls the charge bar to enter the main furnace body and descend to a melting area of a quartz crucible, so that feeding is realized. The production efficiency of the single crystal furnace is improved, and repeated charging can be completed on the premise of not stopping the furnace.

Description

Technical Field

[0001] The present application relates to the field of single crystal silicon rod production equipment, and in particular to a silicon single crystal growth continuous feeding device and a single crystal furnace using the device. Background Art

[0002] In the monocrystalline silicon production industry, all manufacturers are pursuing the economy and production efficiency of the monocrystalline production process. The production process of Czochralski monocrystalline silicon is discontinuous. This feature means that each furnace needs to be loaded, evacuated to pick up leaks, heated and other related operations, which wastes a lot of time and is not conducive to reducing energy consumption.

[0003] In order to improve the efficiency of single crystal pulling, current single crystal silicon manufacturers have widely used a secondary charging method, which reduces the cost of using a crucible and improves the efficiency of single crystal pulling, thereby reducing costs.

[0004] A common secondary feeding method is to set up a heat field outside the single crystal furnace, melt the polysilicon rods in the heat field, form silicon liquid, and add it into the single crystal furnace through a quartz pipe.

[0005] However, due to the high temperature of the silicone liquid, it is easy to melt the quartz pipe when passing through the quartz pipe, and the silicone liquid is easy to remain in the pipe, which will easily clog the pipe when used for a long time. Summary of the invention

[0006] In order to improve the production efficiency of single crystal silicon rods, the present application provides a silicon single crystal growth continuous feeding device and a single crystal furnace using the device.

[0007] In the first aspect, the present application provides a silicon single crystal growth continuous feeding device, which adopts the following technical solution: A continuous feeding device for silicon single crystal growth, comprising a feeding cylinder, a pulling mechanism, a clamping mechanism and a sealing mechanism; The feeding barrel is provided with a feeding port, one end of the feeding barrel is open and the other end is closed; the open end of the feeding barrel is used to connect with the single crystal furnace and communicate with the single crystal furnace; the pulling mechanism is arranged at the closed end of the feeding barrel; the clamping mechanism is arranged inside the feeding barrel; A lifting wire is provided between the clamping mechanism and the lifting mechanism; one end of the lifting wire is connected to the lifting mechanism, and the other end passes through the feeding cylinder and is connected to the clamping mechanism; The sealing mechanism comprises a sealing valve; the sealing valve is arranged at the opening end of the feeding cylinder.

[0008] By adopting the above technical solution, the feeding barrel can be installed on the main furnace body of the single crystal furnace. When feeding into the single crystal furnace, the polysilicon material rod is first hoisted in the feeding barrel through the clamping mechanism, and then the rotary valve is opened. The pulling mechanism controls the material rod to enter the main furnace body and descend to the melt area of ​​the quartz crucible, thereby realizing the feeding. The production efficiency of the single crystal furnace is improved, and multiple feedings can be completed without stopping the furnace. The current problem of blockage when feeding into the furnace through a quartz pipe and the problem of melting of the quartz feed pipe are solved. In addition, the implementation scheme is simple, and the existing single crystal furnace can be modified to realize the function of continuous feeding without the need to increase the heat field.

[0009] Preferably, the clamping mechanism includes a support seat, and the support seat is fixedly connected to the pulling line; a material taking mechanism is provided at the feeding port, and the material taking mechanism includes a material taking rod and a connector connected to the support seat.

[0010] By adopting the above technical solution, the staff operates the material taking rod to pull the connecting sleeve toward the feeding port, thereby driving the clamping mechanism to move toward the feeding port, so that the staff can take out the clamping mechanism with the polysilicon rod from the feeding barrel, which is convenient for replacing the rod material.

[0011] Preferably, the connecting head comprises a connecting sleeve sleeved on a supporting seat, and there is a clearance fit between the connecting sleeve and the supporting seat; the connecting sleeve is connected to the material taking rod.

[0012] By adopting the above technical solution, the lifting mechanism can drive the support seat to rise and cooperate with the connecting sleeve, which is convenient for workers to operate the clamping mechanism. On the contrary, when the lifting mechanism drives the support seat to descend, the support seat can automatically detach from the connecting sleeve, which is convenient for the smooth feeding work.

[0013] Preferably, the connector further comprises a wire protector arranged above the connecting sleeve, and the pulling wire is passed through the wire protector; One end of the wire protector is set as a connecting end and is fixedly connected to the connecting sleeve, and the other end is set as an extending end and extends to the top of the connecting sleeve; the width of the extending end is greater than the width of the fixed end, and there is an arc-shaped transition between the extending end and the fixed end.

[0014] By adopting the above technical scheme, on the one hand, the wire protector can provide better protection for the pulling wire; on the other hand, in the process of removing the clamping mechanism, since the pulling wire is tilted, the pulling wire will exert downward pressure on the wire protector. Based on the principle of mutual force, the pulling wire will receive the reaction force of the wire protector. This reaction force will act on the support seat along the pulling wire, so that the pulling wire can cooperate with the support seat to clamp the connecting sleeve, which can improve the stability of the cooperation between the support seat and the connecting sleeve, and ensure that when the staff takes out the clamping mechanism, the support seat is not easily separated from the connecting sleeve, which is convenient for operation.

[0015] Preferably, the wire protector is arranged in a flat shape.

[0016] By adopting the above technical solution, the wire protection can provide better protection for the pulling wire and can also guide the pulling wire.

[0017] Preferably, the feeding port is arranged in a long strip shape and is arranged along the length direction of the feeding barrel; a sealing cover plate is arranged at the feeding port; and the material taking mechanism is arranged at the upper part of the feeding port.

[0018] By adopting the above technical solution, the staff can connect the material rod with the clamping mechanism through the feeding port, which is convenient for operation.

[0019] Preferably, a guide seat is provided inside the feeding port, and the guide seat is fixedly connected to the feeding barrel; a guide hole is opened on the guide seat; the feeding rod passes through the guide hole and slidably cooperates with the guide seat, and the feeding rod can be moved from the inside of the feeding barrel to the outside of the feeding barrel.

[0020] By adopting the above technical solution, the material picking rod can slide in the guide hole. Therefore, when the staff operates the material picking rod, the guide seat can guide the material picking rod to ensure the stability of the material picking rod and ensure the smooth progress of material picking and feeding.

[0021] Preferably, the guide hole is arranged in a long strip shape and is arranged vertically; a locking sleeve is sleeved on the material picking rod, and the locking sleeve is threadedly connected to the material picking rod.

[0022] By adopting the above technical solution,

[0023] Preferably, the pulling device comprises a motor and a winding drum, the pulling wire is configured as a molybdenum wire, and the end of the pulling wire is fixedly connected to the winding drum.

[0024] By adopting the above technical solution, when the material picking rod moves from the inside of the feeding barrel to the outside of the feeding barrel, the locking sleeve is abutted against the guide seat and the locking sleeve is threadedly connected to the material picking rod. The locking sleeve can limit the material picking rod to prevent the material picking rod from being displaced, and can effectively ensure the stability of the clamping mechanism, so as to facilitate the staff to carry out material changing work.

[0025] Preferably, the pulling device comprises a motor and a winding drum, the pulling wire is configured as a molybdenum wire, and the end of the pulling wire is fixedly connected to the winding drum.

[0026] By adopting the above technical solution, the molybdenum wire has a higher melting point, higher tensile strength, smaller thermal expansion coefficient, smaller elongation, and excellent physical properties. It can effectively carry polysilicon rods and can be used in the high temperature environment of single crystal furnaces. The drive mode of motor and winding drum is efficient and stable, which can ensure the stable operation of the continuous feeding device for silicon single crystal growth.

[0027] On the other hand, the present application provides a single crystal furnace, which adopts the following technical solution: A single crystal furnace comprises a main furnace body, an auxiliary furnace body, and a silicon single crystal growth continuous feeding device; The auxiliary furnace body and the charging cylinder are both arranged above the main furnace body; and the charging cylinder is arranged parallel to the auxiliary furnace body.

[0028] By adopting the above technical solution, the polysilicon rods are hoisted in the feeding barrel through the rod hoisting device, and the lifting mechanism controls the rods to descend to the appropriate melt position in the quartz crucible. The melt position is in the outer ring of the quartz crucible, and the crystal growth area is in the inner ring of the quartz crucible. When melting the material, the crystal can be pulled at the same time. After one rod is melted, the lifting mechanism drives the remaining rods to rise into the barrel, close the rotary valve to isolate the feeding barrel from the single crystal furnace barrel, and replace the rods. After the rod is replaced, the rotary valve can be opened, and the rod can be lowered to the appropriate melt position by the lifting mechanism, and the material can be melted again, and the feeding process is completed once.

[0029] In summary, the present invention includes at least one of the following beneficial technical effects: 1. The feeding barrel can be installed on the main furnace body of the single crystal furnace. When feeding into the single crystal furnace, first hoist the polysilicon rod into the feeding barrel through the clamping mechanism, then open the rotary valve, and the lifting mechanism controls the rod to enter the main furnace body and descend to the melting area of ​​the quartz crucible to achieve feeding. The production efficiency of the single crystal furnace is improved, and multiple feedings can be completed without stopping the furnace. The current problem of blockage when feeding into the furnace through the quartz pipe and the problem of melting of the quartz feed pipe are solved. In addition, the implementation plan is simple, and the existing single crystal furnace can be modified to realize the function of continuous feeding without the need to increase the heat field; 2. The staff can take out the clamping mechanism with the polysilicon rod from the feeding barrel by operating the material taking rod, which is convenient for the replacement of the rod material; and in the process of taking out the clamping mechanism, the support seat and the connecting sleeve can maintain a stable fit, ensuring the smooth progress of the material replacement process and improving work efficiency; 3. When the lifting mechanism drives the clamping mechanism to rise or fall, the support seat can automatically cooperate with or disengage from the connecting sleeve, which can effectively improve the convenience of operation for the staff, thereby helping to improve production efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 It is a schematic diagram of the structure of the single crystal furnace and the continuous feeding device for silicon single crystal growth in Example 1 of the present application; Figure 2 is a cross-sectional view of a continuous feeding device for silicon single crystal growth in Example 2 of the present application; Figure 3 It is a structural schematic diagram of the material taking mechanism and the clamping mechanism when the clamping mechanism is located inside the feeding barrel in Example 2 of the present application; Figure 4 It is a structural schematic diagram of the material taking mechanism and the clamping mechanism when the clamping mechanism is located at the feeding port of the feeding barrel in Example 2 of the present application.

[0031] Markings in the attached drawings: 1. feeding barrel; 11. feeding port; 12. guide seat; 2. lifting mechanism; 21. motor; 22. winding drum; 23. lifting wire; 3. clamping mechanism; 31. supporting seat; 4. sealing mechanism; 5. material taking mechanism; 51. material taking rod; 52. connecting head; 521. connecting sleeve; 522. wire protector; 53. locking sleeve; 6. main furnace body; 7. auxiliary furnace body; 8. quartz crucible. DETAILED DESCRIPTION

[0032] The following is combined with Figure 1-4 The present invention is described in further detail.

[0033] Example 1 The present application discloses a continuous feeding device for growing silicon single crystals. Figure 1 The silicon single crystal growth continuous feeding device comprises a feeding barrel 1, a pulling mechanism 2, a clamping mechanism 3 and a sealing mechanism 4. The feeding barrel 1 is open at one end and closed at the other end. The open end of the feeding barrel 1 is used to connect with the single crystal furnace and communicate with the inside of the single crystal furnace.

[0034] The pulling mechanism 2 is arranged at the closed end of the feeding barrel 1, and the pulling mechanism 2 includes a motor 21 fixed on the feeding barrel 1 and a winding drum 22 fixedly connected to the output end of the motor 21. A pulling wire 23 made of molybdenum wire is wound on the winding drum 22. The pulling wire 23 passes through the feeding barrel 1 and enters the interior of the feeding barrel 1.

[0035] The clamping mechanism 3 includes a support seat 31 fixedly connected to the pulling wire 23 and a crystal rod chuck fixedly connected to the support seat 31. The polycrystalline silicon rod can be fixedly connected to the crystal rod chuck, so that the pulling mechanism 2 drives the polycrystalline silicon rod to move up and down through the clamping mechanism 3.

[0036] The sealing mechanism 4 includes a sealing valve, which is arranged at the opening end of the charging cylinder 1, and the charging cylinder 1 is connected to the single crystal furnace through the sealing valve. The sealing valve is a rotary valve.

[0037] The present application also discloses a single crystal furnace, referring to Figure 1 The single crystal furnace includes a main furnace body 6, an auxiliary furnace body 7, and the above-mentioned silicon single crystal growth continuous feeding device. The auxiliary furnace body 7 and the feeding cylinder 1 are both arranged above the main furnace body 6, the auxiliary furnace body 7 is located at the center of the top of the main furnace body 6, and the feeding cylinder 1 is located on one side of the auxiliary furnace body 7. And the feeding cylinder 1 is arranged in parallel with the auxiliary furnace body 7. The feeding cylinder 1 is fixedly connected to the main furnace body 6 through a sealing valve. The sealing valve can isolate the feeding cylinder 1 and the main furnace body 6.

[0038] A quartz crucible 8 is also disposed in the main furnace body 6 , and the feeding tube 1 is disposed toward the outer circle of the quartz crucible 8 .

[0039] The implementation principle of the single crystal furnace in the embodiment of the present application is: when starting to add material, first hoist the polysilicon material rod in the feeding tube 1 through the clamping mechanism 3, open the rotary valve, and the pulling mechanism 2 controls the material rod to enter the main furnace body 6 and descend to a suitable melt position. The melt position is located in the outer circle of the quartz crucible 8, and the crystal growth area is in the inner circle of the quartz crucible 8.

[0040] Crystal pulling can be done while melting the material. After a material rod is melted, the motor 21 drives the winding drum 22 to rotate, driving the molybdenum wire to rise, and then driving the material rod to the upper limit position, and closing the rotary valve to isolate the feeding barrel 1 from the main furnace body 6. After the material rod is replaced, open the rotary valve, and the material rod is lowered to the appropriate melting position through the pulling mechanism 2, and the material can be melted again.

[0041] Example 2 The present application discloses a continuous feeding device for growing silicon single crystals. Figure 2 , which is different from Example 1, is that a feeding port 11 is provided on the side wall of the feeding barrel 1, and the feeding port 11 is arranged in a long strip shape and arranged along the length direction of the feeding barrel 1. A material taking mechanism 5 is arranged at the feeding port 11, and the material taking mechanism 5 is arranged at the upper part of the feeding port 11.

[0042] Reference Figure 1 and Figure 2, the material picking mechanism 5 includes a material picking rod 51 and a connector 52. The connector 52 includes a connecting sleeve 521, and the material picking rod 51 is fixedly connected to the connecting sleeve 521. The connecting sleeve 521 is sleeved on the support seat 31, and there is a clearance fit between the connecting sleeve 521 and the support seat 31. A pull-wire protector 522 is fixedly connected above the connecting sleeve 521. The pull-wire protector 522 is arranged in a flat cylindrical shape as a whole. One end of the pull-wire protector 522 is arranged as a connecting end and is fixedly connected to the connecting sleeve 521, and the other end is arranged as an extension end and extends to the top of the connecting sleeve 521. The width of the extension end is greater than the width of the fixed end, and there is an arc-shaped transition between the extension end and the fixed end. The pulling wire 23 is passed through the inside of the pull-wire protector 522.

[0043] Reference Figure 3 and Figure 4 , the staff operates the material taking rod 51 to pull the connecting sleeve 521 to move toward the feeding port 11, thereby driving the clamping mechanism 3 to move toward the feeding port 11, so that the staff can take out the clamping mechanism 3 with the polysilicon rod from the feeding barrel 1, which is convenient for the staff to replace the rod material. In the process of taking out the clamping mechanism 3, since the pulling wire 23 is set at an angle, the pulling wire 23 will exert downward pressure on the pulling wire protector 522. Based on the principle of mutual force, since the pulling wire 23 is fixedly connected to the support seat 31, the pulling wire 23 will cooperate with the support seat 31 to clamp the connecting sleeve 521, which can improve the stability of the cooperation between the support seat 31 and the connecting sleeve 521, and ensure that when the staff takes out the clamping mechanism 3, the support seat 31 is not easily separated from the connecting sleeve 521, which is convenient for operation.

[0044] After the bar material is replaced, the staff can operate the material taking rod 51 to put the bar material back into the feeding barrel 1. When the lifting mechanism 2 drives the bar material to move downward, the support seat 31 will be separated from the connecting sleeve 521. At this time, in order to prevent the connecting sleeve 521 from falling under its own gravity, a limit block can be set on the inner wall of the feeding barrel 1, so that the connecting sleeve 521 is placed on the limit block, so as to play a better supporting role for the connecting sleeve 521.

[0045] Reference Figure 2 , a guide seat 12 is also provided at the feeding port, and the guide seat 12 is fixedly connected to the feeding barrel 1. A guide hole is provided on the guide seat 12, and the guide holes are arranged in a long strip shape and distributed vertically. The width of the guide hole is the same as the diameter of the feeding rod 51. The feeding rod 51 passes through the guide hole and slides with the guide seat 12, so that the feeding rod 51 can slide in the guide hole, so that the feeding rod 51 can move from the inside of the feeding barrel 1 to the outside of the feeding barrel 1. When the staff operates the feeding rod 51, the guide seat 12 can guide the feeding rod 51, so as to ensure the stability of the feeding rod 51, so as to ensure the smooth progress of feeding and feeding.

[0046] The material taking rod 51 is also sleeved with a locking sleeve 53, which is threadedly connected to the material taking rod 51. When the material taking rod 51 moves from the inside of the feeding barrel 1 to the outside of the feeding barrel 1, the locking sleeve 53 is abutted against the guide seat 12 and the locking sleeve 53 is threadedly connected to the material taking rod 51. The locking sleeve 53 can limit the material taking rod 51 to prevent the material taking rod 51 from being displaced, and can effectively ensure the stability of the clamping mechanism 3, so that the staff can perform material changing work.

[0047] The embodiments of this specific implementation method are all preferred embodiments of the present invention, and are not intended to limit the protection scope of the present invention. Therefore, all equivalent changes made based on the structure, shape, and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A continuous feeding device for silicon single crystal growth, characterized in that: It comprises a feeding cylinder (1), a lifting mechanism (2), a clamping mechanism (3) and a sealing mechanism (4); The feeding barrel (1) is provided with a feeding port (11); one end of the feeding barrel (1) is open and the other end is closed; the open end of the feeding barrel (1) is used to connect to the single crystal furnace and communicate with the inside of the single crystal furnace; the pulling mechanism (2) is arranged at the closed end of the feeding barrel (1); the clamping mechanism (3) is arranged inside the feeding barrel (1); A lifting wire (23) is provided between the clamping mechanism (3) and the lifting mechanism (2); one end of the lifting wire (23) is connected to the lifting mechanism (2), and the other end passes through the feeding cylinder (1) and is connected to the clamping mechanism (3); The sealing mechanism (4) comprises a sealing valve; the sealing valve is arranged at the opening end of the feeding cylinder (1).

2. The silicon single crystal growth continuous feeding device according to claim 1, characterized in that: The clamping mechanism (3) comprises a support seat (31), and the support seat (31) is fixedly connected to the pulling line (23); a material taking mechanism (5) is provided at the feeding port (11), and the material taking mechanism (5) comprises a material taking rod (51) and a connecting head (52) connected to the support seat (31).

3. The continuous feeding device for silicon single crystal growth according to claim 2, characterized in that: The connecting head (52) comprises a connecting sleeve (521) sleeved on the supporting seat (31), and a clearance fit is formed between the connecting sleeve (521) and the supporting seat (31); the connecting sleeve (521) is connected to the material taking rod (51).

4. The silicon single crystal growth continuous feeding device according to claim 3, characterized in that: The connecting head (52) further comprises a wire protector (522) arranged above the connecting sleeve (521), and the pulling wire (23) is passed through the inside of the wire protector (522); One end of the wire protector (522) is configured as a connecting end and is fixedly connected to the connecting sleeve (521), and the other end is configured as an extending end and extends to the top of the connecting sleeve (521); the width of the extending end is greater than the width of the fixed end, and an arc-shaped transition is formed between the extending end and the fixed end.

5. The silicon single crystal growth continuous feeding device according to claim 4, characterized in that: The pull wire protector (522) is arranged in a flat shape.

6. The silicon single crystal growth continuous feeding device according to claim 2, characterized in that: The feeding port (11) is arranged in a long strip shape and is arranged along the length direction of the feeding barrel (1); a sealing cover plate is arranged at the feeding port (11); and the material taking mechanism (5) is arranged at the upper part of the feeding port (11).

7. The silicon single crystal growth continuous feeding device according to claim 6, characterized in that: A guide seat (12) is provided inside the feeding port, and the guide seat (12) is fixedly connected to the feeding barrel (1); a guide hole is provided on the guide seat (12); the feeding rod (51) passes through the guide hole and slidably cooperates with the guide seat (12); the feeding rod (51) can move from the inside of the feeding barrel (1) to the outside of the feeding barrel (1).

8. The silicon single crystal growth continuous feeding device according to claim 7, characterized in that: The guide hole is arranged in a long strip shape and is arranged vertically; a locking sleeve (53) is sleeved on the material taking rod (51), and the locking sleeve (53) is threadedly connected to the material taking rod (51).

9. The silicon single crystal growth continuous feeding device according to claim 1, characterized in that: The pulling device comprises a motor (21) and a winding drum (22); the pulling wire (23) is provided as a molybdenum wire; and the end of the pulling wire (23) is fixedly connected to the winding drum (22).

10. A single crystal furnace, characterized in that: It comprises a main furnace body (6), an auxiliary furnace body (7), and a silicon single crystal growth continuous feeding device as claimed in any one of claims 1 to 9; The auxiliary furnace body (7) and the charging cylinder (1) are both arranged above the main furnace body (6); and the charging cylinder (1) is arranged in parallel with the auxiliary furnace body (7).

Images