Single crystal silicon growth apparatus

Abstract

The present application relates to a single crystal silicon growth device, comprising: a crucible; a side heater comprising a plurality of heating pieces; the plurality of heating pieces are sequentially distributed along the circumference of the crucible to form a surrounding cavity, and the crucible is inserted into the surrounding cavity; and the lateral size of the surrounding cavity is adjusted by adjusting the position of the heating pieces. The single crystal silicon growth device of the present application optimizes the structure of the side heater, can adapt to different specifications of the crucible, and does not need to replace the side heater.

Description

Technical Field

[0001] This invention relates to the field of monocrystalline silicon production technology, and in particular to a monocrystalline silicon growth apparatus. Background Technology

[0002] Monocrystalline silicon is usually prepared by the Czochralski method. During preparation, polycrystalline silicon is placed in a quartz crucible and heated to a high temperature and melted into a liquid state under vacuum conditions using argon as a protective gas. A seed crystal with a specific crystal orientation is then brought into contact with the surface of the molten silicon. The seed crystal is pulled upward and rotated, so that the molten silicon grows into monocrystalline silicon using the crystal structure of the seed crystal as a template.

[0003] The thermal field of existing single-crystal silicon growth equipment mainly includes side heaters and bottom heaters. The side heaters are usually annular and surround the quartz crucible to heat the side walls of the quartz crucible. The bottom heaters are located at the bottom of the quartz crucible to heat the bottom of the quartz crucible.

[0004] The existing thermal field of single-crystal silicon growth equipment has the following main defects:

[0005] (1) For quartz crucibles of different specifications, side heaters of corresponding sizes are required, but side heaters are expensive and replacement costs are high.

[0006] (2) A vent is provided at the bottom of the hot zone to discharge the argon gas inside the single crystal silicon growth device. Since the internal space of the single crystal silicon growth device is limited, the vent is close to the foot plate of the bottom heater. The argon gas will carry volatile substances (including oxides, such as silicon monoxide) generated during the single crystal silicon growth process. The foot plate of the bottom heater will heat up when energized. During the flow of argon gas through the vent, the oxides carried by the argon gas will stick to the foot plate of the bottom heater. Since the foot plate is at a high temperature, the oxides stuck to the foot plate are easily heated and burned, causing sparking and creating production hazards.

[0007] (3) After the polysilicon has melted, the bottom heater stops heating. The bottom heater is still in the original hot field position. The bottom heater is easy to come into contact with the gas containing impurities, which makes it easy to oxidize and corrode, thus shortening the service life of the bottom heater. Summary of the Invention

[0008] In view of the above-mentioned defects in the prior art, the purpose of the present invention is to provide a single crystal silicon growth apparatus that optimizes the structure of the side heater, can adapt to crucibles of different specifications, eliminates the need to replace the side heater, and reduces or saves replacement costs.

[0009] Therefore, the present invention provides the following technical solution.

[0010] This invention provides a single-crystal silicon growth apparatus, the single-crystal silicon growth apparatus comprising:

[0011] crucible;

[0012] A side heater includes multiple heating elements; the multiple heating elements are sequentially distributed along the circumference of the crucible to form an enclosing cavity, in which the crucible is inserted; the lateral dimension of the enclosing cavity is adjusted by adjusting the position of the heating elements.

[0013] The above solution optimizes the structure of the side heater by setting it into a structure of multiple heating plates, making the lateral dimension of the cavity surrounding the side heater adjustable. In this way, compared with the existing technology that uses a single ring-shaped side heater, the monocrystalline silicon growth apparatus of the present invention can adapt to crucibles of different specifications by adjusting the position of the heating plates, without the need to replace the side heater, thus reducing or eliminating replacement costs.

[0014] Preferably, the single-crystal silicon growth apparatus further includes a plurality of first telescopic mechanisms, the driving ends of the first telescopic mechanisms being connected to the heating elements one by one; the first telescopic mechanisms are used to drive the heating elements to move, so as to adjust the lateral dimensions of the enclosing cavity.

[0015] The above solution, by configuring a first telescopic mechanism, can automatically adjust the position of the heating element, making operation simple and automated.

[0016] Preferably, the single-crystal silicon growth apparatus further includes multiple sets of first electrodes; the heating element is connected to a set of first feet, and each set of first feet is connected to the positive and negative terminals of the first electrodes, and each first electrode is connected to the driving end of the first telescopic mechanism; in this scheme, the driving end of the first telescopic mechanism drives the first electrodes to move, thereby driving the first feet and the heating element to move synchronously, so as to adjust the position of the heating element. In this way, the distance between the first telescopic mechanism and the heating element can be increased as much as possible, so as to avoid the heat generated by the heating element during the heating process causing the first telescopic mechanism to overheat.

[0017] And / or, when the molten material in the single crystal silicon growth apparatus is in the cooling process, the first telescopic mechanism is used to drive the heating element to move, thereby increasing the lateral dimension of the surrounding cavity; in this solution, when the molten material is in the cooling process, the lateral dimension of the surrounding cavity is increased by the first telescopic mechanism, thereby increasing the distance between the heating element and the crucible, preventing the crucible from scraping or squeezing the side heater due to tilting, and improving the service life of the side heater.

[0018] Preferably, the single-crystal silicon growth apparatus includes multiple sets of first electrodes; the heating element is connected to a set of first feet, and each set of first feet is connected to the positive and negative terminals of the set of first electrodes; the lateral dimension of the enclosing cavity can be adjusted by replacing the first feet of different lengths.

[0019] The above solution eliminates the need for an additional first telescopic mechanism and allows for manual adjustment of the heating element's position, thereby reducing the overall processing cost of the machine.

[0020] Preferably, the heating element is a graphite heating element; thus, the graphite heating element heats up quickly, has high heating efficiency, and precise temperature control.

[0021] And / or, the heating element is arc-shaped; thus, the crucible is circular, and all the heating elements can form a circularly shaped enclosing cavity, which is beneficial for providing uniform side heating;

[0022] And / or, all of the heating elements are arranged in a circumferential array; this facilitates the provision of uniform side heating.

[0023] And / or, the heating element is connected to a first foot plate, the length of which extends radially along the crucible; thus, the first foot plate is located above the bottom hot field, and the distance between the first foot plate and the gas inlet located in the bottom hot field is relatively safe, minimizing contact between the first foot plate and impurities carried by the argon gas.

[0024] Preferably, the single-crystal silicon growth apparatus further includes:

[0025] A bottom heater is located below the crucible; the bottom heater switches between a working position and a storage position by means of movement.

[0026] The air inlet is located in the bottom thermal field below the crucible;

[0027] Specifically, when the bottom heater is in the working position, the bottom heater is located in the bottom thermal field; when the bottom heater moves toward the storage position, the bottom heater moves in a direction away from the bottom thermal field to move away from the air guide hole.

[0028] The above solution optimizes the structure of the bottom heater, allowing it to switch between a working position and a retractable position. When in the working position, the bottom heater performs its heating function. When heating is not required, the bottom heater moves to the retractable position to increase the distance between it and the gas vent. This minimizes contact between the argon-carrying oxides and the bottom heater during the flow of argon gas through the gas vent, reducing the probability of combustion due to oxides adhering to the bottom heater and being heated, thus mitigating potential production hazards. Furthermore, by reducing contact between the bottom heater and gases containing impurities in the bottom heat field, oxidation and corrosion of the bottom heater are prevented, extending its service life.

[0029] Preferably, the bottom heater includes multiple heating elements; the single crystal silicon growth apparatus further includes multiple second telescopic mechanisms, the driving ends of the second telescopic mechanisms being connected to the heating elements one by one; the second telescopic mechanisms are used to drive the heating elements to move, so that the bottom heater switches between a working position and a retracted position.

[0030] The above solution, by configuring a second telescopic mechanism to adjust the position of the bottom heater, is simple to operate and automated.

[0031] Preferably, the single-crystal silicon growth apparatus further includes multiple sets of second electrodes; the heating element is connected to a set of second feet, and each set of second feet is connected to the positive and negative poles of the set of second electrodes, and each second electrode is connected to the driving end of the second telescopic mechanism.

[0032] In the above scheme, the driving end of the second telescopic mechanism drives the second electrode to move, thereby causing the second foot plate and the heating element to move synchronously. In this way, the distance between the second telescopic mechanism and the heating element can be increased as much as possible to avoid the heat generated by the heating element during the heating process causing the second telescopic mechanism to overheat.

[0033] Preferably, when the bottom heater is in the retracted position, the bottom heater is retracted into the housing of the second telescopic mechanism.

[0034] In the above scheme, the housing of the second telescopic mechanism also serves to store and protect the bottom heater, so as to prevent the bottom heater from being scratched.

[0035] Preferably, the single crystal silicon growth apparatus further includes a first heat-insulating cylinder and a rotary drive mechanism. The first heat-insulating cylinder surrounds the bottom hot field and is provided with a plurality of first clearance through holes. The heating element is arranged in a one-to-one correspondence with the first clearance through holes.

[0036] When the bottom heater switches between the working position and the storage position, the heating element passes through the corresponding first clearance through hole;

[0037] When the bottom heater is in the retracted position, the bottom heater is located outside the first insulation cylinder. The rotary drive mechanism is used to drive the first insulation cylinder to rotate so that the cylinder wall of the first insulation cylinder separates the bottom heater from the bottom heat field.

[0038] In the above scheme, the monocrystalline silicon growth apparatus is equipped with a first insulation cylinder to maintain heat and reduce heat loss from the bottom hot zone. The first insulation cylinder has a first clearance through-hole to allow for the connection between the heating element and the second telescopic mechanism. When the bottom heater is in the retracted position, it is located outside the first insulation cylinder, and the rotation of the first insulation cylinder isolates the bottom heater from the bottom hot zone, effectively preventing contact between the bottom heater and the airflow in the bottom hot zone. This effectively prevents oxidation and corrosion of the bottom heater and extends its service life.

[0039] The present invention has the following technical effects:

[0040] (1) The present invention provides a single crystal silicon growth apparatus. By optimizing the structure of the side heater, the side heater is configured as a structure of multiple heating plates, so that the lateral dimension of the cavity surrounding the side heater is adjustable. In this way, compared with the prior art using a single ring-shaped side heater, the single crystal silicon growth apparatus of the present invention can adapt to crucibles of different specifications by adjusting the position of the heating plates, without the need to replace the side heater, thus reducing or eliminating replacement costs.

[0041] (2) The present invention provides a single crystal silicon growth apparatus, which optimizes the structure of the bottom heater. The bottom heater can switch between the working position and the storage position. When the bottom heater is in the working position, the bottom heater realizes the heating function. When the bottom heater does not need to be turned on for heating, the bottom heater switches to the storage position by movement to increase the distance between the bottom heater and the gas guide hole. In this way, during the process of argon carrying oxides flowing to the gas guide hole, the contact between the oxides carried by argon and the bottom heater can be avoided as much as possible, thereby reducing the probability of combustion caused by the oxides sticking to the bottom heater and being heated, and reducing production hazards.

[0042] (3) The present invention provides a single crystal silicon growth apparatus, which optimizes the structure of the bottom heater. When the bottom heater does not need to be turned on for heating, it can reduce the contact between the bottom heater and the gas containing impurities in the bottom hot field, prevent the bottom heater from oxidizing and corroding, and improve the service life of the bottom heater. Attached Figure Description

[0043] Figure 1 This is a partial three-dimensional structural diagram of the single-crystal silicon growth apparatus of the present invention. Figure 1 ;

[0044] Figure 2 This is a perspective view of the assembly structure of the side heater and crucible of the present invention;

[0045] Figure 3 This is a top view of the assembly structure of the side heater and crucible of the present invention;

[0046] Figure 4 This is a partial three-dimensional structural diagram of the single-crystal silicon growth apparatus of the present invention. Figure 2 ;

[0047] Figure 5 A cross-sectional view of a partial structure of the single-crystal silicon growth apparatus of the present invention. Figure 1 ;

[0048] Figure 6 This is a partial three-dimensional structural diagram of the single-crystal silicon growth apparatus of the present invention. Figure 3 ;

[0049] Figure 7 A cross-sectional view of a partial structure of the single-crystal silicon growth apparatus of the present invention. Figure 2 .

[0050] Explanation of reference numerals in the attached figures

[0051] 100. Single crystal silicon growth apparatus;

[0052] 1. Crucible;

[0053] 2. Side heater; 21. Heating element; 22. Enclosing cavity; 23. First foot plate;

[0054] 3. Bottom heater; 31. Heating element; 32. Second foot plate;

[0055] 4. Air vent;

[0056] 5. Bottom heating zone;

[0057] 6. Second telescopic mechanism;

[0058] 7. Rotary drive mechanism;

[0059] 81. First insulation cylinder; 811. First clearance through hole; 82. Second insulation cylinder; 821. Second clearance through hole; 83. Protective sleeve;

[0060] 91. First curing felt; 911. Third clearance through hole; 92. Second curing felt; 921. Fourth clearance through hole; 93. Base; 931. Annular through hole. Detailed Implementation

[0061] To make the technical solution and beneficial effects of the present invention more apparent and understandable, a detailed description is provided below by listing specific embodiments. Unless otherwise defined, the technical and scientific terms used herein have the same meanings as those in the technical field to which this application pertains.

[0062] In the description of this invention, unless otherwise expressly defined, the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "height," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," and "counterclockwise," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the purpose of simplifying the description of this invention and do not indicate that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. That is, they should not be construed as limiting this invention.

[0063] In this invention, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating the relative importance of the indicated features or the number of indicated technical features. Therefore, a feature specified as "first" or "second" can explicitly include at least one of that feature. In the description of this invention, "a plurality of" means at least two; "several" means at least one; unless otherwise expressly defined.

[0064] In this invention, unless otherwise explicitly defined, the terms "installation," "connection," "linking," "fixing," and "setting," etc., should be interpreted broadly. For example, "connection" can be a fixed connection, a detachable connection, or an integral molding; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium; it can also refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0065] In this invention, unless otherwise explicitly defined, the terms "above," "on top of," "over," "above," "below," "below," "below," or "below" for "first feature above second feature" can refer to the first and second features being in direct contact, or to the first and second features being in indirect contact through an intermediate medium. Furthermore, "above," "over," and "below" for "first feature above second feature" can mean the first feature is directly above or diagonally above the second feature, or simply indicates that the horizontal height of the first feature is higher than the horizontal height of the second feature. Similarly, "below," "below," and "below" for "first feature below second feature" can mean the first feature is directly below or diagonally below the second feature, or simply indicates that the horizontal height of the first feature is lower than the horizontal height of the second feature.

[0066] In this invention, "upper" and "lower" are both used in the sense of... Figure 1 and Figure 5 The markings in the text shall prevail.

[0067] The following is based on Figures 1 to 7 The single-crystal silicon growth apparatus of the present invention is described in detail.

[0068] In this embodiment, such as Figure 1 , Figure 2 , Figure 3 , Figure 6 and Figure 7 As shown, the single crystal silicon growth apparatus 100 includes a crucible 1, a side heater 2, a bottom heater 3, and a gas vent 4. The crucible 1 can be a quartz crucible and is used to contain silicon material. The bottom heater 3 is located below the crucible 1 and is used to heat the bottom of the crucible 1. The gas inlet of the gas vent 4 is located in the bottom thermal field 5 below the crucible 1. Argon gas introduced into the single crystal silicon growth apparatus 100 during use is discharged through the gas vent 4.

[0069] The side heater 2 includes multiple heating elements 21. The number of heating elements 21 can be two, three, or even more. Preferably, to simplify the assembly process of the side heater 2, the number of heating elements 21 is two or three. The multiple heating elements 21 are distributed sequentially along the circumference of the crucible 1 to form a surrounding cavity 22. The crucible 1 is inserted into the surrounding cavity 22. That is, the multiple heating elements 21 cooperate to circumferentially surround the crucible 1, and the side heater 2 is used to heat the sidewall of the crucible 1. For growing silicon rods of different diameters, the size of the crucible 1 will also be adjusted accordingly. In order to adapt to crucibles of different sizes, it is necessary to adjust the lateral dimension of the surrounding cavity 22. In this invention, since the heating elements 21 are sheet-shaped and located on one side of the crucible 1, the heating elements 21 do not completely surround the crucible 1. Therefore, the crucible 1 will not interfere with the position adjustment of the heating elements 21. Thus, by adjusting the position of the heating elements 21, the lateral dimension of the surrounding cavity 22 can be adjusted, thereby enabling the side heater 2 to adapt to crucibles of different sizes.

[0070] The above technical solution optimizes the structure of the side heater 2 by setting it into a structure of multiple heating elements 21, making the lateral dimension of the cavity 22 surrounding the side heater 2 adjustable. In this way, compared with the prior art using a single ring-shaped side heater, the single crystal silicon growth apparatus 100 of the present invention can adapt to crucibles 1 of different specifications by adjusting the position of the heating elements 21, without replacing the side heater 2, thus reducing or eliminating replacement costs.

[0071] It should be understood that in order to ensure that the side heater 2 can heat evenly, the distance between any part of the side heater 2 and the crucible 1 must be equal or the error of the distance must be controlled within the allowable range.

[0072] It should be understood that when the position of the heating element 21 is adjusted in this invention, the shape and size of the heating element 21 will not change, or the shape of the heating element 21 will be slightly deformed due to the allowable error during the assembly of the heating element 21. Such slight deformation has a negligible impact on the size of the surrounding cavity 22. Of course, when assembling the heating element 21, it is necessary to avoid deformation of the heating element 21 due to assembly. On the one hand, this avoids affecting the precise adjustment of the lateral size of the surrounding cavity 22. On the other hand, it avoids the heating element 21 being in a deformed state for a long time, which would cause uncontrollable changes in the shape of the heating element 21 when it returns to a free state, which is not conducive to uniform heating of the side of the crucible 1.

[0073] It should be understood that the formation of the surrounding cavity 22 can be formed by all the heating elements 21 being distributed sequentially along the circumference of the crucible 1, or by some of the heating elements 21 being distributed sequentially along the circumference of the crucible 1 to form one surrounding cavity 22, and the remaining heating elements 21 being distributed sequentially along the circumference of the crucible 1 to form another surrounding cavity 22. The different surrounding cavities 22 are staggered along the vertical direction of the crucible 1. That is to say, the side heater 2 can have multiple surrounding cavities 22 staggered along the vertical direction of the crucible 1.

[0074] It should be understood that the prior art uses a ring-shaped side heater surrounding the crucible. Since the shape and size of the ring-shaped side heater determine the size of the enclosed cavity it forms, the crucible restricts the position of the side heater. Therefore, the prior art cannot adapt to crucibles of different sizes by adjusting the position of the ring-shaped side heater.

[0075] In one implementation, such as Figure 2 and Figure 3 As shown, during the growth of single-crystal silicon, the crucible 1 needs to rotate continuously while the seed crystal rotates in the opposite direction. To ensure that the molten silicon in the crucible 1 can form a uniform and symmetrical flow pattern, the cross-section of the crucible 1 is circular. Multiple or all of the heating elements 21 are distributed sequentially along the circumference, and the central axis of the circumference where the side heaters 2 are located coincides with the central axis of the crucible 1. Thus, the lateral dimension of the surrounding cavity 22 refers to the diameter of the surrounding cavity 22.

[0076] In one embodiment, the single-crystal silicon growth apparatus 100 further includes multiple first telescopic mechanisms (not shown in the figure). These first telescopic mechanisms include, but are not limited to, linear motors (such as a mechanism consisting of a motor and a lead screw and nut assembly) and pneumatic cylinders. The drive ends of the first telescopic mechanisms are connected to the heating elements 21 one by one, and are used to drive the heating elements 21 to move, thereby adjusting the lateral dimension of the surrounding cavity 22. Specifically, when the side heater 2 needs to accommodate a larger crucible 1, the drive end of the first telescopic mechanism retracts, causing the heating elements 21 to move away from the crucible 1, thereby increasing the lateral dimension of the surrounding cavity 22; when the side heater 2 needs to accommodate a smaller crucible 1, the drive end of the first telescopic mechanism extends, causing the heating elements 21 to move towards the crucible 1, thereby decreasing the lateral dimension of the surrounding cavity 22. This solution, by configuring the first telescopic mechanisms, can automatically adjust the position of the heating elements 21, making operation simple and automated.

[0077] Furthermore, the single-crystal silicon growth apparatus 100 also includes multiple sets of first electrodes (not shown in the figure). A set of first feet 23 are connected to the heating element 21. Each set of first feet 23 is connected to the positive and negative terminals of the first electrodes. The heating element 21 is installed by connecting the first feet 23 to the first electrodes. The connection between the first feet 23, the heating element 21, and the first electrodes can be secured using conductive bolts. The first electrodes are electrically connected to a power source. When the first electrodes are energized, the heating element 21 generates heat to achieve side heating. Each first electrode is connected to a corresponding drive end of the first telescopic mechanism. Thus, the drive end of the first telescopic mechanism moves the first electrodes, causing the first feet 23 and the heating element 21 to move synchronously, thereby adjusting the position of the heating element 21. This maximizes the distance between the first telescopic mechanism and the heating element 21 to prevent overheating of the first telescopic mechanism due to heat generated by the heating element 21 during heating.

[0078] Furthermore, when the molten material in the single crystal silicon growth apparatus 100 is in the cooling process, both the side heater 2 and the bottom heater 3 are in the off state. The remaining material in the crucible 1 gradually cools down, and the rotation speed of the crucible 1 gradually decreases. Due to the uneven cooling of the remaining material in the crucible 1, the crucible 1 may tilt. The crucible 1 may easily scrape or squeeze the side heater 2. At this time, the first telescopic mechanism drives the heating plate 21 to move, so as to increase the lateral dimension of the surrounding cavity 22 and increase the distance between the heating plate 21 and the crucible 1, so as to avoid the crucible 1 scraping or squeezing the side heater 2 due to tilting, and improve the service life of the side heater 2.

[0079] In another embodiment, the lateral dimension of the surrounding cavity 22 is adjusted by replacing the first foot plate 23 with one of different lengths. Specifically, this solution eliminates the need for an additional first telescopic mechanism, reducing the overall processing cost. When the side heater 2 needs to accommodate a larger crucible 1, requiring an increase in the lateral dimension of the surrounding cavity 22, the heating element 21 is manually moved away from the crucible 1. Since the position of the first electrode remains fixed, the distance between the heating element 21 and the first electrode decreases. By replacing the first foot plate 23 with one of smaller dimensions, the heating element 21 can be electrically connected to the first electrode. When the side heater 2 needs to accommodate a smaller crucible 1, requiring a decrease in the lateral dimension of the surrounding cavity 22, the heating element 21 is manually moved towards the crucible 1, increasing the distance between the heating element 21 and the first electrode. By replacing the first foot plate 23 with one of larger dimensions, the heating element 21 can be electrically connected to the first electrode.

[0080] In one embodiment, the heating element 21 is a graphite heating element, which has a fast heating speed, high heating efficiency, and precise temperature control.

[0081] In one implementation, such as Figure 2 and Figure 3 As shown, the heating element 21 is arc-shaped. Specifically, the crucible 1 is circular. All the heating elements 21 can form a circular cavity 22, which is beneficial for providing uniform side heating.

[0082] In one implementation, such as Figure 2 and Figure 3 As shown, all the heating elements 21 are arranged in a circumferential array, which is beneficial for providing uniform side heating.

[0083] In one implementation, such as Figure 2 , Figure 3 , Figure 4 , Figure 6 and Figure 7 As shown, the heating plate 21 is connected to the first foot plate 23. The length of the first foot plate 23 extends radially along the crucible 1. In this way, the first foot plate 23 is located above the bottom heat field 5. The distance between the first foot plate 23 and the gas guide hole 4 is relatively safe, minimizing the contact between the first foot plate 23 and impurities carried by the argon gas.

[0084] In one embodiment, the bottom heater 3 is movably disposed and can move to switch between a working position and a storage position. When the bottom heater 3 is in the working position, it is located in the bottom thermal field 5. During the heating process, the bottom heater 3 transfers heat to the bottom thermal field 5 to heat the bottom of the crucible 1, thus achieving the bottom heating function. When the heating process is completed (e.g., after the material is completely melted, during crystal growth), the bottom heater 3 stops heating and then switches its position to the storage position. As the bottom heater 3 moves toward the storage position, it moves away from the bottom thermal field 5, thus moving it away from the vent hole 4. In this way, by increasing the distance between the bottom heater 3 and the vent hole 4, the contact between the oxide carried by the argon gas and the bottom heater 3 can be minimized during the flow of argon gas carrying oxides into the vent hole 4.

[0085] The above technical solution also optimizes the structure of the bottom heater 3, enabling it to switch between a working position and a storage position. When the bottom heater 3 is in the working position, it performs the heating function. When the bottom heater 3 does not need to be heated, it moves to the storage position to increase the distance between it and the gas guide hole 4. This minimizes the contact between the oxide carried by the argon gas and the bottom heater 3 during the flow of argon gas carrying oxides to the gas guide hole 4, thereby reducing the probability of combustion caused by the oxides adhering to the bottom heater 3 and reducing potential production hazards. Furthermore, by reducing the contact between the bottom heater 3 and the impurity-containing gas in the bottom hot zone 5, oxidation and corrosion of the bottom heater 3 can be prevented, thus improving its service life.

[0086] In one implementation, such as Figure 6 and Figure 7 As shown, the bottom heater 3 includes multiple heating elements 31. The number of heating elements 31 can be two, three, or even more. Preferably, to simplify the assembly process of the bottom heater 3, the number of heating elements 31 is four. The single-crystal silicon growth apparatus 100 also includes multiple second telescopic mechanisms 6. The second telescopic mechanisms 6 include, but are not limited to, linear motors (such as a mechanism consisting of a motor and a lead screw and nut assembly) and pneumatic cylinders. The drive end of the second telescopic mechanism 6 is connected to each heating element 31. The second telescopic mechanism 6 is used to drive the heating elements 31 to move, so that the bottom heater 3 switches between a working position and a retracted position. Figure 6Only the housing of the second telescopic mechanism 6 is shown; the specific motion drive mechanism and limiting mechanism are located inside the housing. Specifically, when the bottom heater 3 needs to switch from the working position to the retracted position, the drive end of the second telescopic mechanism 6 retracts to move the heating element 31 away from the bottom heat field 5; when the bottom heater 3 needs to switch from the retracted position to the working position, the drive end of the second telescopic mechanism 6 extends to move the heating element 31 towards the bottom heat field 5. This solution, by configuring the second telescopic mechanism 6 to adjust the position of the bottom heater 3, is simple and automated to operate.

[0087] Furthermore, the single-crystal silicon growth apparatus 100 also includes multiple sets of second electrodes (not shown in the figure). A set of second feet 32 ​​is connected to the heating element 31, and each second foot 32 is connected to one of the second electrodes. The installation of the heating element 31 is achieved through the electrical connection between the second feet 32 ​​and the second electrodes. The connection between the second feet 32, the heating element 31, and the second electrodes can be secured with conductive bolts. When the second electrodes are energized, the heating element 31 generates heat to achieve the bottom heating function. Each second electrode is correspondingly connected to the drive end of the second telescopic mechanism 6. Thus, the drive end of the second telescopic mechanism 6 drives the second electrodes to move, thereby causing the second feet 32 ​​and the heating element 31 to move synchronously.

[0088] In one embodiment, when the bottom heater 3 is in the retracted position, the bottom heater 3 is retracted into the housing of the second telescopic mechanism 6. The housing of the second telescopic mechanism 6 also serves to store and protect the bottom heater 3 to prevent the bottom heater 3 from being scratched.

[0089] In one implementation, such as Figure 5 and Figure 7 As shown, the single-crystal silicon growth apparatus 100 also includes a first heat-insulating cylinder 81 and a rotary drive mechanism 7. The first heat-insulating cylinder 81 surrounds the bottom hot zone 5 and serves to insulate the heat, thereby reducing heat loss from the bottom hot zone 5. The first heat-insulating cylinder 81 is provided with a plurality of first clearance through holes 811, and the heating element 31 is provided with a one-to-one correspondence between the first clearance through holes 811 and the heating element 31.

[0090] When the bottom heater 3 switches between the working position and the storage position, the heating element 31 passes through the corresponding first clearance through hole 811. Specifically, when the bottom heater 3 is in the working position, the heating element 31 passes through the corresponding first clearance through hole 811. Part of the structure of the heating element 31 is located outside the first heat preservation cylinder 81 to connect with the second telescopic mechanism 6. Part of the structure of the heating element 31 is located in the bottom heat field 5 inside the first heat preservation cylinder 81. The first clearance through hole 811 is used to allow the connection between the heating element 31 and the second telescopic mechanism 6.

[0091] When the bottom heater 3 is in the retracted position, it is located outside the first insulation cylinder 81. At this time, the bottom heater 3 is separated from the bottom heat field 5. However, since the first clearance through hole 811 is opposite to the bottom heater 3, some airflow in the bottom heat field 5 will pass through the first clearance through hole 811 and come into contact with the bottom heater 3. In order to avoid the bottom heater 3 from coming into contact with the airflow in the bottom heat field 5, the first insulation cylinder 81 is driven to rotate by the rotation drive mechanism 7. The first insulation cylinder 81 rotates at a certain angle, so that the bottom heater 3 is completely misaligned with the first clearance through hole 811. At this time, the cylinder wall of the first insulation cylinder 81 separates the bottom heater 3 from the bottom heat field 5, which can effectively prevent the bottom heater 3 from coming into contact with the airflow in the bottom heat field 5, thereby effectively preventing the bottom heater 3 from oxidizing and corroding and improving the service life of the bottom heater 3.

[0092] Furthermore, such as Figure 6 As shown, the heating element 31 is elongated. While ensuring the heating effect, the cross-sectional size of the heating element 31 is reduced, thereby minimizing the size of the first clearance through hole 811 and reducing the impact of the setting of the first clearance through hole 811 on the heat preservation performance of the first heat preservation cylinder 81 as much as possible.

[0093] In one implementation, such as Figure 6 As shown, all the second foot plates 32 are symmetrically arranged around the rotation axis of the crucible 1, and the length extension directions of two adjacent heating elements 31 are perpendicular to each other to ensure uniform heating. Of course, the arrangement of the heating elements 31 is not limited to this. It can be that all the heating elements 31 are symmetrically arranged around the rotation axis of the crucible 1, or that several adjacent heating elements 31 form a group of heating units, and all groups of heating units are symmetrically arranged around the rotation axis of the crucible 1.

[0094] In one implementation, such as Figure 5 As shown, the single-crystal silicon growth apparatus 100 also includes a second insulation cylinder 82, which surrounds the side heater 2 to provide insulation for the side thermal field formed by the side heater 2. The bottom wall of the second insulation cylinder 82 is fitted with the top wall of the first insulation cylinder 81 with a small gap to minimize heat loss caused by the gap while avoiding interference from the rotation of the first insulation cylinder 81 by the second insulation cylinder 82. The second insulation cylinder 82 is provided with a second clearance through hole 821, through which a first foot plate 23 passes. One end of the first foot plate 23 is located inside the second insulation cylinder 82 to connect with the heating element 21, and the other end of the first foot plate 23 extends to the outside of the second insulation cylinder 82 to connect with the first electrode.

[0095] Furthermore, such as Figure 1 , Figure 4 and Figure 5As shown, the single crystal silicon growth apparatus 100 also includes a plurality of protective sleeves 83, which are arranged one-to-one with the first foot plate 23, and the protective sleeves 83 are fitted around the outer periphery of the corresponding first foot plate 23 to protect the first foot plate 23.

[0096] In one implementation, such as Figure 1 , Figures 4 to 7 As shown, the single-crystal silicon growth apparatus 100 also includes a first curing felt 91, a second curing felt 92, and a base 93. The first curing felt 91 surrounds the first insulation cylinder 81 with their surfaces in contact, and the second curing felt 92 surrounds the second insulation cylinder 82 with their surfaces in contact. The bottom wall of the second curing felt 92 abuts against the top wall of the first curing felt 91. The first curing felt 91 is mounted on the base 93, and a vent hole 4 is provided on the base 93. The thickness of both the first curing felt 91 and the second curing felt 92 is greater than that of the first insulation cylinder 81 and the second insulation cylinder 82. The first curing felt 91 and the second curing felt 92 provide support, insulation, and protection. Furthermore, the single-crystal silicon growth apparatus 100 also includes an outer shell (not shown in the figure), which surrounds the first curing felt 91 and the second curing felt 92 to improve the aesthetic appearance of the single-crystal silicon growth apparatus 100.

[0097] Furthermore, such as Figure 4 , Figure 5 and Figure 7 As shown, the first curing felt 91 is provided with a third clearance through hole 911, and the second curing felt 92 is provided with a fourth clearance through hole 921. The third clearance through hole 911 communicates with the first clearance through hole 811 so that the heating element 31 can pass through. Of course, when the bottom heater 3 is in the working position, the second foot plate 32 can also be located at least partially in the third clearance through hole 911. The fourth clearance through hole 921 communicates with the second clearance through hole 821 so that the first foot plate 23 can pass through, and the protective sleeve 83 is located in the fourth clearance through hole 921.

[0098] In one implementation, such as Figure 6 and Figure 7 As shown, the rotary drive mechanism 7 is movably mounted below the base 93. The base 93 has an annular through hole 931, through which the first insulation cylinder 81 passes to connect with the drive end of the rotary drive mechanism 7. The rotary drive mechanism 7 may include a motor and a turntable (not shown in the figure). The turntable serves as the drive end of the rotary drive mechanism 7, and the motor drives the turntable to rotate the first insulation cylinder 81.

[0099] In one specific embodiment, the single crystal silicon growth apparatus 100 adjusts the position of the heating element 21 through the first telescopic mechanism. When using the single crystal silicon growth apparatus 100, if the crucible 1 needs to be replaced, the position of the heating element 21 is adjusted through the first telescopic mechanism according to the outer diameter of the crucible 1. After the position is adjusted, single crystal silicon growth can be carried out. After the melting stage is completed, the side heater 2 and the bottom heater 3 are turned off. The second telescopic mechanism 6 drives the heating element 31 and the second foot plate 32 to move synchronously to the storage position. The rotation drive mechanism 7 drives the first heat preservation cylinder 81 to rotate a certain angle to separate the bottom heater 3 from the bottom heat field 5. The single crystal silicon growth apparatus 100 starts the crystal growth operation. After the crystal growth is completed, the heating element 21 is driven to move away from the crucible 1 through the first telescopic mechanism to prevent the crucible 1 from tilting and scraping or squeezing the heating element 21 during the cooling stage.

[0100] It should be understood that the above embodiments are exemplary and are not intended to encompass all possible implementations included in the claims. Various modifications and changes can be made to the above embodiments without departing from the scope of this disclosure. Similarly, the various technical features of the above embodiments can be arbitrarily combined to form other embodiments of the present invention that may not be explicitly described. Therefore, the above embodiments only illustrate several implementations of the present invention and do not limit the scope of protection of this patent.

Claims

1. A single-crystal silicon growth apparatus, characterized in that, The single-crystal silicon growth apparatus (100) includes: Crucible (1); A side heater (2) includes a plurality of heating elements (21); the plurality of heating elements (21) are arranged sequentially along the circumference of the crucible (1) to form an enclosing cavity (22), the crucible (1) being inserted into the enclosing cavity (22); the lateral dimension of the enclosing cavity (22) is adjusted by adjusting the position of the heating elements (21); A bottom heater (3) is located below the crucible (1); the bottom heater (3) switches between a working position and a storage position by means of movement; The air inlet (4) is located in the bottom thermal field (5) below the crucible (1); When the bottom heater (3) is in the working position, the bottom heater (3) is located in the bottom heat field (5); when the bottom heater (3) moves toward the storage position, the bottom heater (3) moves away from the bottom heat field (5) to move away from the air guide hole (4).

2. The single-crystal silicon growth apparatus according to claim 1, characterized in that, The single-crystal silicon growth apparatus (100) also includes a plurality of first telescopic mechanisms, the driving ends of the first telescopic mechanisms being connected one by one to the heating element (21); the first telescopic mechanism is used to drive the heating element (21) to move in order to adjust the lateral dimension of the surrounding cavity (22).

3. The single-crystal silicon growth apparatus according to claim 2, characterized in that, The single crystal silicon growth apparatus (100) also includes multiple sets of first electrodes; the heating element (21) is connected to a set of first foot plates (23), and the positive and negative poles of the set of first electrodes are connected one by one, and the first electrodes are connected one by one to the driving end of the first telescopic mechanism. And / or, when the molten material in the single crystal silicon growth apparatus (100) is in the cooling process, the first telescopic mechanism is used to drive the heating element (21) to move in order to increase the lateral dimension of the surrounding cavity (22).

4. The single-crystal silicon growth apparatus according to claim 1, characterized in that, The single-crystal silicon growth apparatus (100) includes multiple sets of first electrodes; the heating plate (21) is connected to a set of first feet (23), and the first feet (23) are connected one by one to the positive and negative poles of the first electrodes; by changing the first feet (23) of different lengths, the lateral dimension of the surrounding cavity (22) can be adjusted.

5. The single-crystal silicon growth apparatus according to any one of claims 1-4, characterized in that, The heating element (21) is a graphite heating element; And / or, the heating element (21) is arc-shaped; And / or, all of the heating elements (21) are arranged in a circumferential array; And / or, the heating element (21) is connected to a first foot plate (23), the length of which extends radially along the crucible (1).

6. The single-crystal silicon growth apparatus according to any one of claims 1-4, characterized in that, The bottom heater (3) includes multiple heating elements (31); the single crystal silicon growth apparatus (100) also includes multiple second telescopic mechanisms (6), the driving ends of the second telescopic mechanisms (6) are connected to the heating elements (31) one by one; the second telescopic mechanisms (6) are used to drive the heating elements (31) to move so that the bottom heater (3) switches between the working position and the storage position.

7. The single-crystal silicon growth apparatus according to claim 6, characterized in that, The single-crystal silicon growth apparatus (100) also includes multiple sets of second electrodes; the heating element (31) is connected to a set of second foot plates (32), and the positive and negative poles of the set of second electrodes are connected one by one, and the second electrodes are connected one by one to the driving end of the second telescopic mechanism (6).

8. The single-crystal silicon growth apparatus according to claim 6, characterized in that, When the bottom heater (3) is in the retracted position, the bottom heater (3) is retracted into the housing of the second telescopic mechanism (6).

9. The single-crystal silicon growth apparatus according to claim 6, characterized in that, The single crystal silicon growth apparatus (100) further includes a first heat preservation cylinder (81) and a rotary drive mechanism (7). The first heat preservation cylinder (81) surrounds the bottom heat field (5). The first heat preservation cylinder (81) is provided with a plurality of first clearance through holes (811). The heating element (31) is provided with one-to-one correspondence with the first clearance through holes (811). When the bottom heater (3) switches between the working position and the storage position, the heating element (31) passes through the corresponding first clearance through hole (811). When the bottom heater (3) is in the storage position, the bottom heater (3) is located outside the first insulation cylinder (81), and the rotary drive mechanism (7) is used to drive the first insulation cylinder (81) to rotate so that the cylinder wall of the first insulation cylinder (81) separates the bottom heater (3) from the bottom heat field (5).

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