Crystal ingot growth method and crystal ingot growth apparatus

Abstract

The present disclosure relates to a crystal ingot growth method, which uses a single crystal furnace to perform crystal ingot growth. The single crystal furnace comprises a crucible used to contain a silicon melt, and the method comprises the following steps: immersing a seed crystal in the silicon melt to seed a crystal ingot, and applying a horizontal magnetic field having a magnetic field strength of a first preset value, in an axial direction of the crystal ingot, a first distance between a strongest Gaussian surface of the horizontal magnetic field and a liquid surface of the silicon melt in the axial direction of the crystal ingot being less than a second preset value; performing constant diameter growth of the crystal ingot, and applying a cusped magnetic field having a magnetic field strength of a third preset value, a zero magnetic surface of the cusped magnetic field being located at an R arc position of the crucible. The present disclosure also relates to a crystal ingot growth apparatus.

Description

Crystal ingot growth method and crystal ingot growth device

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This disclosure claims priority to Chinese Patent Application No. 202310707576.0 filed in China on June 14, 2023, the entire contents of which are incorporated herein by reference. Technical Field

[0003] The present disclosure relates to the technical field of semiconductor product manufacturing, and in particular to a crystal rod growth method and a crystal rod growth device. Background Art

[0004] Oxygen is a crucial metric in evaluating the quality of crystal ingots. The radial oxygen gradient (ROG) significantly impacts back-end yield. Oxygen can also form bulk micro defects (BMDs) within the wafer bulk. These BMDs act as internal gettering agents, effectively absorbing and capturing surface defects, creating a defect-free zone near the wafer surface. This is highly beneficial for chip circuit etching and significantly improves back-end product yield. However, the crystal pulling process is an extremely complex directional solidification process, primarily due to the uncertain convection in the melt. This high uncertainty in convection leads to uncertainty in oxygen precipitation from the melt and oxygen incorporation into the ingot. Furthermore, this uncertain convection leads to an unstable solid-liquid interface at the ingot, which in turn leads to unstable crystal pulling. Slight fluctuations can lead to the formation of crystal defects within the ingot, while larger fluctuations can cause the ingot to lose its single-crystal properties, resulting in loss of single crystal properties (LOSS).

[0005] Summary of the Invention

[0006] In order to solve the above technical problems, the present disclosure provides a crystal ingot growth method and a crystal ingot growth device to solve the problem that the uncertainty of silicon melt convection affects the uniformity of oxygen in the crystal ingot.

[0007] The present disclosure provides a method for growing a crystal ingot, wherein a single crystal furnace is used to grow the crystal ingot. The single crystal furnace includes a crucible for containing molten silicon, and the method includes the following steps:

[0008] Immersing a seed crystal in a silicon melt for seeding to form a crystal rod, and applying a horizontal magnetic field having a magnetic field strength of a first preset value, wherein a first distance between a strongest Gaussian surface of the horizontal magnetic field and a liquid surface of the silicon solution in an axial direction of the crystal rod is less than a second preset value;

[0009] The crystal rod is grown in equal diameter, and a cusp magnetic field having a magnetic field strength of a third preset value is applied, wherein the zero magnetic plane of the cusp magnetic field is located at the R arc portion of the crucible.

[0010] Optionally, the crystal ingot growth method further includes:

[0011] The seeded crystal rod is shouldered, and before entering the equal diameter growth process, the intensity of the horizontal magnetic field is increased from the first preset value to a fourth preset value.

[0012] Optionally, the seeded crystal ingot is shouldered, and when the diameter of the crystal ingot is greater than or equal to 80% of the target equal diameter length, the horizontal magnetic field strength is increased to the fourth preset value.

[0013] Optionally, the step of growing the crystal rods in equal diameters and applying a cusp magnetic field having a magnetic field strength of a third preset value comprises:

[0014] While applying the cusp magnetic field, the intensity of the horizontal magnetic field is increased from the fourth preset value to a fifth preset value.

[0015] Optionally, the first preset value is 1100-1300 Gauss, the fourth preset value is 1450-1550 Gauss, and the fifth preset value is 2100-2300 Gauss.

[0016] Optionally, the third preset value is 1400-1600 Guass.

[0017] Optionally, the crystal ingot growth method further includes:

[0018] The position of the strongest Gaussian surface is adjusted so that the first distance is always smaller than the first preset value during the crystal pulling process.

[0019] Optionally, the crystal ingot growth method further includes:

[0020] The position of the zero magnetic surface is adjusted so that the zero magnetic surface is always located at the R-arc position of the crucible during the crystal pulling process.

[0021] The present disclosure also provides a crystal ingot growing device, comprising:

[0022] furnace body;

[0023] A crucible is located in the furnace body, and the crucible contains molten silicon;

[0024] a horizontal magnetic field generating structure, disposed on the periphery of the furnace body and configured to output a horizontal magnetic field to the crucible;

[0025] A cusp magnetic field generating structure is arranged at the periphery of the furnace body and is used to output a cusp magnetic field to the crucible. The cusp magnetic field generating structure is located on a side of the horizontal magnetic field generating structure away from the top of the furnace body.

[0026] Optionally, the crystal ingot growing device further includes:

[0027] a first regulating structure for controlling the movement of the horizontal magnetic field generating structure in the axial direction of the crystal ingot so that, during the crystal pulling process, the distance between the strongest Gaussian plane of the horizontal magnetic field and the liquid surface of the silicon solution is less than a first preset value;

[0028] The second regulating structure is used to control the movement of the cusp magnetic field generating structure in the axial direction of the crystal rod, so that the zero magnetic plane of the cusp magnetic field is always located at the R-arc portion of the crucible during the crystal pulling process.

[0029] The beneficial effects of the present disclosure are: applying the horizontal magnetic field in the seeding stage, and making the distance between the strongest Gaussian surface and the liquid surface of the silicon solution in the axial direction of the crystal rod less than a second preset value, thereby suppressing the convection of the silicon melt, suppressing the volatilization of oxygen, and improving the stability of the solid-liquid interface, thereby improving the problem of uncertainty in the precipitation of oxygen in the melt and the oxygen immersion in the crystal rod due to the uncertainty of the convection of the silicon melt, and improving the quality of the crystal rod.

[0030] A cusp magnetic field is applied in the equal diameter stage, and the zero magnetic surface of the cusp magnetic field is located at the R arc portion of the crucible to promote the precipitation of oxygen. The cusp magnetic field cooperates with the horizontal magnetic field to allow oxygen to be effectively and evenly immersed in the crystal rod. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] FIG1 is a schematic flow chart of a crystal growth method according to an embodiment of the present disclosure;

[0032] FIG2 shows a schematic diagram of a crystal growth apparatus according to an embodiment of the present disclosure;

[0033] FIG3 shows a second schematic diagram of the crystal growth apparatus in an embodiment of the present disclosure. DETAILED DESCRIPTION

[0034] To make the purpose, technical solutions, and advantages of the embodiments of the present disclosure more clear, the technical solutions of the embodiments of the present disclosure will be clearly and completely described below in conjunction with the accompanying drawings of the embodiments of the present disclosure. Obviously, the described embodiments are part of the embodiments of the present disclosure, not all of the embodiments. Based on the described embodiments of the present disclosure, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present disclosure.

[0035] Unless otherwise defined, the technical or scientific terms used in this disclosure should have the usual meanings understood by people with ordinary skills in the field to which this disclosure belongs. The words "first", "second" and similar words used in this disclosure do not indicate any order, quantity or importance, but are only used to distinguish different components. Similarly, words such as "one", "an" or "the" do not indicate a quantity limitation, but rather indicate the existence of at least one. Words such as "include" or "comprise" mean that the elements or objects appearing before the word include the elements or objects listed after the word and their equivalents, without excluding other elements or objects. Words such as "connect" or "connected" are not limited to physical or mechanical connections, but may include electrical connections, whether direct or indirect. "Up", "down", "left", "right" and the like are only used to indicate relative positional relationships. When the absolute position of the object being described changes, the relative positional relationship may also change accordingly.

[0036] 1 to 3 , this embodiment provides a method for growing a crystal ingot, wherein a single crystal furnace is used to grow the crystal ingot. The single crystal furnace includes a crucible for containing molten silicon, and the method includes the following steps:

[0037] Immersing a seed crystal in a silicon melt for seeding to form a crystal rod 1, and applying a horizontal magnetic field having a magnetic field strength of a first preset value, wherein in the axial direction of the crystal rod, a first distance between a strongest Gaussian surface 5 of the horizontal magnetic field and a liquid surface of the silicon solution is less than a second preset value;

[0038] The crystal rod is grown in equal diameters, and a cusp magnetic field having a magnetic field strength of a third preset value is applied, wherein the zero magnetic plane 7 of the cusp magnetic field is located at the R arc portion of the crucible.

[0039] A horizontal magnetic field is applied in the initial stage of crystal pulling, and a first distance between the maximum Gauss plane 5 (Maximum Gauss Plane, MGP) of the horizontal magnetic field and the liquid surface of the silicon solution in the axial direction of the crystal rod is made less than a second preset value. The horizontal magnetic field suppresses the convection of the silicon melt and the volatilization of oxygen, thereby improving the uncertainty of the convection of the silicon melt, which leads to the uncertainty of the oxygen precipitation in the melt and the oxygen immersion in the crystal rod, improving the stability of the solid-liquid interface, and preventing the crystal rod from losing its single crystal characteristics due to large fluctuations.

[0040] It should be noted that, in one embodiment, the first preset value is 1100-1300 Gauss, for example 1200 Gauss, which suppresses the convection of the silicon melt while avoiding excessive magnetic field intensity, which causes the temperature in the furnace to drop and thus affects the pulling of the crystal rod, but is not limited to this.

[0041] It should be noted that, in some embodiments, the third preset value is 1400-1600 Guass. Preferably, the third preset value is 1500 Guass, but the present invention is not limited thereto.

[0042] It should be noted that the second preset value is 2-3 mm, but is not limited thereto.

[0043] In some embodiments, in order to effectively suppress the convection of the silicon melt and improve the stability of the solid-liquid interface, the strongest Gaussian surface 5 coincides with the liquid surface of the silicon melt.

[0044] In an exemplary embodiment, the crystal ingot growth method further includes:

[0045] The seeded crystal rod is shouldered, and before entering the equal diameter growth process, the intensity of the horizontal magnetic field is increased from the first preset value to a fourth preset value.

[0046] Since the crystal pulling process conditions may vary in different crystal pulling steps, the intensity of the horizontal magnetic field may be adjusted accordingly according to actual needs to effectively suppress the convection of the silicon melt.

[0047] Before entering the equal-diameter growth process, increasing the intensity of the horizontal magnetic field from the first preset value to a fourth preset value can increase the stability of the solid-liquid interface and thus improve the stability of the crystal rod.

[0048] In some embodiments, the fourth preset value is 1450-1550 Gauss. Optionally, the fourth preset value is 1500 Gauss, but is not limited thereto.

[0049] It should be noted that in the above steps, it is sufficient to increase the intensity of the horizontal magnetic field from the first preset value to the fourth preset value before entering the equal-diameter growth process, and the specific time point for increasing the intensity of the horizontal magnetic field from the first preset value to the fourth preset value can be set according to actual needs.

[0050] In an exemplary embodiment, the seeded crystal ingot is shouldered, and when the diameter of the crystal ingot is greater than or equal to 80% of the target equal diameter length, the horizontal magnetic field strength is increased to the fourth preset value, but the present invention is not limited thereto.

[0051] In an exemplary embodiment, the step of growing the crystal rods in equal diameters and applying a cusp magnetic field having a magnetic field strength of a third preset value comprises:

[0052] While applying the cusp magnetic field, the intensity of the horizontal magnetic field is increased from the fourth preset value to a fifth preset value.

[0053] When entering the isodiameter growth stage, in order to effectively suppress convection, the magnetic field strength of the horizontal magnetic field needs to be further enhanced.

[0054] Exemplarily, the fifth preset value is 2100-2300 Guass. Optionally, the fifth preset value is 2200 Guass, but is not limited thereto.

[0055] In a specific embodiment, the crystal growth method comprises the following steps:

[0056] Immersing the seed crystal in a silicon melt for seeding to form a crystal rod, and applying a horizontal magnetic field with a magnetic field strength of 1200 Guass, with the strongest Gaussian surface 5 of the horizontal magnetic field coinciding with the liquid surface of the silicon melt;

[0057] The seeded ingot is shouldered and when the ingot diameter is greater than or equal to 80% of the target equal diameter length, the horizontal magnetic field strength is increased to 1500 guass.

[0058] The crystal rod is grown in equal diameter and a cusp magnetic field (CUSP magnetic field) with a magnetic field strength of 1500 Guass is applied, with the zero magnetic plane 7 (i.e., Zero Gauss Plane, ZGP) of the cusp magnetic field located at the R arc portion of the crucible. At the same time, the strength of the horizontal magnetic field is increased to 2200 Guass.

[0059] It should be noted that the horizontal magnetic field and the cusp magnetic field do not interfere with each other, so as to avoid affecting the positions of the strongest Gaussian surface 5 and the zero magnetic surface 7, thereby avoiding affecting the oxygen uniformity of the crystal rod.

[0060] In an exemplary embodiment, the crystal ingot growth method further includes:

[0061] The position of the strongest Gaussian surface 5 is adjusted so that the first distance is always smaller than the first preset value during the crystal pulling process.

[0062] In order to ensure the inhibitory effect of the horizontal magnetic field on the convection of the silicon melt, during the crystal pulling process, the distance between the strongest Gaussian surface 5 of the horizontal magnetic field and the liquid surface of the silicon solution in the axial direction of the crystal rod must always be kept less than the first preset value. Optionally, during the crystal pulling process, the distance between the strongest Gaussian surface 5 of the horizontal magnetic field and the liquid surface of the silicon solution in the axial direction of the crystal rod must always be kept zero, that is, the strongest Gaussian surface 5 of the horizontal magnetic field coincides with the liquid surface of the silicon solution.

[0063] In order to ensure that the strongest Gaussian surface 5 coincides with the liquid surface of the silicon melt, it is necessary to determine the distance between the strongest Gaussian surface 5 and the liquid surface of the silicon melt. The following specifically describes the process of adjusting the relative position relationship between the strongest Gaussian surface 5 and the liquid surface of the silicon melt.

[0064] 3 , determine a second distance b between the first position of the furnace body and the liquid level of the silicon solution in the axial direction of the crystal rod;

[0065] According to the second distance b, the first distance (i.e., the distance between the strongest Gaussian surface 5 and the liquid surface of the silicon melt in the axial direction of the crystal rod) c is determined, c=a+db, a is the distance between the first end face of the horizontal magnetic field generating structure in the axial direction of the crystal rod (the horizontal magnetic field generating structure is located on the periphery of the furnace body and is used to provide a horizontal magnetic field to the crucible. The end face of the horizontal magnetic field generating structure away from the silicon solution is the first end face) and the first position, and d is the distance between the first end face and the Gaussian surface 5 with the strongest magnetic field in the axial direction of the crystal rod.

[0066] When c is not zero, the horizontal magnetic field generating structure is controlled to move in the axial direction of the crystal rod so that the strongest Gaussian surface 5 coincides with the liquid surface of the silicon solution.

[0067] For example, when c is greater than zero, it indicates that the strongest Gaussian surface 5 is located above the liquid surface of the silicon melt, and the horizontal magnetic field generating structure can be controlled to move along the axial direction of the crystal rod, toward the direction of the silicon melt; when c is less than zero, it indicates that the strongest Gaussian surface 5 is located below the silicon melt, and the horizontal magnetic field generating structure can be controlled to move along the axial direction of the crystal rod, away from the silicon melt; or, when c is greater than zero, it indicates that the strongest Gaussian surface 5 is located below the liquid surface of the silicon melt, and the horizontal magnetic field generating structure can be controlled to move along the axial direction of the crystal rod, away from the silicon melt; when c is less than zero, it indicates that the strongest Gaussian surface 5 is located above the silicon melt, and the horizontal magnetic field generating structure can be controlled to move along the axial direction of the crystal rod, toward the direction of the silicon melt.

[0068] In an exemplary embodiment, the crystal ingot growth method further includes:

[0069] The position of the zero magnetic surface 7 is adjusted so that the zero magnetic surface 7 is always located at the R-arc portion of the crucible during the crystal pulling process.

[0070] According to the different specifications of the oxygen content of the target crystal rod, the relative position of the zero magnetic plane 7 of the cusp magnetic field and the R arc part, or the intensity of the cusp magnetic field (the greater the magnetic field intensity, the more oxygen is precipitated) can be adjusted accordingly to control the effective precipitation of oxygen.

[0071] During the crystal pulling process, as the crystal rod is lifted, the crucible will rise. In order to ensure that the zero magnetic surface 7 of the cusp magnetic field is always located at the R-arc position, the cusp magnetic field generating structure and the crucible can be made to move synchronously, that is, it is sufficient to determine the initial position of the zero magnetic surface 7 according to the R-arc position of the crucible.

[0072] The crucible is supported and fixed by the crucible shaft at the bottom. The initial length of the crucible shaft is set to h, the length of the R arc portion in the axial direction of the crystal rod is set to g, the distance between the second end face of the sharp magnetic field generating structure away from the horizontal magnetic field generating structure and the zero magnetic surface 7 is set to k, and the distance between the bottom of the furnace body and the second end face is set to j. Then, the zero magnetic surface 7 is located at the R arc portion, and h is required. <k+j<g+h。

[0073] 2 and 3 ( FIG. 3 shows a crystal ingot 1 ), the crystal ingot growth method in this embodiment is implemented by a crystal ingot growing device, which includes:

[0074] furnace body;

[0075] A crucible 9 is located in the furnace body, and the crucible 9 contains molten silicon;

[0076] The guide tube 3 is located above the silicon melt;

[0077] The water cooling jacket 2 is located on the side of the guide tube 3 away from the silicon melt;

[0078] A horizontal magnetic field generating structure 4 is provided on the periphery of the furnace body and is used to output a horizontal magnetic field to the crucible 9;

[0079] a cusp magnetic field generating structure 6, disposed on the periphery of the furnace body, for outputting a cusp magnetic field to the crucible 9, the cusp magnetic field generating structure 6 being located on a side of the horizontal magnetic field generating structure 4 away from the top of the furnace body;

[0080] A seed crystal pulling structure, used to control the seed crystal 12 to move up and down in the first direction (i.e., the axial direction of the furnace body);

[0081] A first sensing structure 13 is provided on the furnace body and is located at a first position of the furnace body in the first direction, and is configured to emit a first signal when the seed crystal lifting structure controls the seed crystal to descend through the first position. The second position is a position flush with the silicon melt liquid level 8;

[0082] a second sensing structure, disposed on the furnace body, configured to emit a second signal when the seed crystal pulling structure controls the seed crystal to descend to a second position;

[0083] a processing structure, configured to obtain a second distance b between the first position and the second position in the first direction based on the first signal and the second signal, and obtain the first distance c based on the second distance b, wherein c=a+db, a is the distance between the first end surface and the first position in the first direction, and d is the distance between the first end surface and the Gaussian surface 5 with the strongest magnetic field in the first direction;

[0084] The first adjustment structure is used to control the movement of the horizontal magnetic field generating structure in the axial direction of the crystal rod according to the feedback of the processing structure, so that during the crystal pulling process, the distance between the strongest Gaussian surface 5 of the horizontal magnetic field and the liquid surface of the silicon solution is less than a first preset value.

[0085] By setting up the first and second sensing structures, information such as time and speed is recorded when the seed crystal passes through the first and second positions during its descent, thereby obtaining a second distance b between the first and second positions in the first direction. The distance a between the first end face and the first position can be obtained by direct measurement. The position of the magnetic field generating structure is fixed, so the strongest Gaussian plane is fixed. The distance d between the first end face and the strongest Gaussian plane 5 of the magnetic field in the first direction can be obtained based on the first end face of the magnetic field generating structure. In this way, the distance MP between the strongest Gaussian plane and the silicon melt can be obtained as MP = a + db. Using the above scheme to obtain the distance MP between the strongest Gaussian plane and the silicon melt improves the accuracy of this parameter and is simple and quick.

[0086] The specific structural forms of the first sensing structure can be various. Exemplarily, the first sensing structure includes a beam sensor, and a signal transmitting part and a signal receiving part of the beam sensor are located on opposite sides of the furnace body.

[0087] The positions of the signal transmitting portion and the signal receiving portion in the first direction are both located at the first position, so that the first signal can be accurately emitted when the seed crystal passes through the first position.

[0088] The setting position of the radiation sensor can be set according to actual needs, that is, the first position can be set according to actual needs, as long as it is located above the crucible in the furnace body. Exemplarily, the furnace body includes a main body and a cover body, and the signal transmitting part and the signal receiving part are located on opposite sides of the cover body.

[0089] The through-beam sensor may be arranged on the outer surface of the cover, so as to avoid affecting the components in the furnace.

[0090] The specific structural form of the second sensing structure can be various, as long as it can emit the second signal when the seed crystal contacts the surface of the silicon melt. Exemplarily, the second sensing structure includes a current detection element, one end of the current detection element is connected to the seed crystal pulling structure, and the other end of the current detection element is immersed in the silicon melt. The second sensing structure is used to emit the second signal when the seed crystal is controlled by the seed crystal pulling structure to descend until the seed crystal contacts the silicon melt.

[0091] When the seed crystal head contacts the surface of the silicon melt, the seed crystal pulling structure forms a loop with the silicon melt, the resistance value changes (the current changes), and the processing structure receives the second signal and obtains the distance between the first position and the second position in the first direction based on the first signal.

[0092] It should be noted that the second sensing structure may further include a monitoring element for monitoring changes in the current detection element and sending the second signal when a change in the current of the current detection element is detected, but the present invention is not limited thereto.

[0093] The monitoring element may include a switching circuit and a position information acquisition structure. When the seed crystal head contacts the surface of the silicon melt, the seed crystal pulling structure forms a loop with the silicon melt, the resistance value changes (the current changes), and the switching circuit is closed, thereby sending a signal to the position information acquisition structure, so that the position information acquisition structure obtains the distance between the first position and the second position based on information such as the movement speed of the seed crystal and the time required to move from the first position to the second position, but is not limited to this.

[0094] Exemplarily, the seed crystal pulling structure includes a seed crystal chuck 11 and a seed crystal 12 fixed to the seed crystal chuck 11, and one end of the current sensing element is connected to the seed crystal chuck 11. Exemplarily, the crucible 9 includes a quartz crucible and a graphite crucible located outside the quartz crucible, and the bottom of the graphite crucible is supported and fixed by a crucible shaft 10.

[0095] Exemplarily, a crucible tray is provided between the graphite crucible and the crucible shaft.

[0096] Exemplarily, the crystal ingot growing device further includes:

[0097] a first regulating structure, configured to control the movement of the horizontal magnetic field generating structure in the axial direction of the crystal ingot based on feedback from the processing structure, so that during the crystal pulling process, the distance between the strongest Gaussian plane 5 of the horizontal magnetic field and the liquid surface of the silicon solution is less than a first preset value;

[0098] The second regulating structure is used to control the movement of the cusp magnetic field generating structure in the axial direction of the crystal rod, so that the zero magnetic plane 7 of the cusp magnetic field is always located at the R-arc portion of the crucible during the crystal pulling process.

[0099] Specifically, the second regulating structure is used to control the cusp magnetic field generating structure to rise and fall synchronously with the crucible, so that the zero magnetic surface 7 of the cusp magnetic field is always located at the R-arc portion of the crucible.

[0100] It is understood that the above embodiments are merely exemplary embodiments for illustrating the principles of the present disclosure, and the present disclosure is not limited thereto. Those skilled in the art may make various modifications and improvements without departing from the spirit and substance of the present disclosure, and such modifications and improvements are also considered to be within the scope of protection of the present disclosure.

Claims

1. A method for growing a crystal rod, using a single crystal furnace to grow the crystal rod, wherein the single crystal furnace includes a crucible for containing silicon melt, comprising the following steps: Immersing a seed crystal in a silicon melt for seeding to form a crystal rod, and applying a horizontal magnetic field with a magnetic field strength of a first preset value, wherein in the axial direction of the crystal rod, a first distance between a strongest Gaussian surface of the horizontal magnetic field and a liquid surface of the silicon solution in the axial direction of the crystal rod is less than a second preset value; The crystal rod is grown with equal diameter, and a cusp magnetic field with a magnetic field strength of a third preset value is applied, wherein the zero magnetic plane of the cusp magnetic field is located at the R arc position of the crucible.

2. The method for growing a crystal rod according to claim 1, wherein: Also includes: The crystal rod after seeding is shouldered, and before entering the equal diameter growth process, the intensity of the horizontal magnetic field is increased from the first preset value to a fourth preset value.

3. The method for growing a crystal rod according to claim 2, wherein: The seeded crystal rod is shouldered, and when the diameter of the crystal rod is greater than or equal to 80% of the target equal diameter length, the horizontal magnetic field strength is increased to the fourth preset value.

4. The method for growing a crystal rod according to claim 2, wherein: The step of growing the crystal rod with equal diameter and applying a cusp magnetic field with a magnetic field strength of a third preset value comprises: While applying the cusp magnetic field, the intensity of the horizontal magnetic field is increased from the fourth preset value to a fifth preset value.

5. The method for growing a crystal rod according to claim 4, wherein: The first preset value is 1100-1300 Gauss, the fourth preset value is 1450-1550 Gauss, and the fifth preset value is 2100-2300 Gauss.

6. The method for growing a crystal rod according to claim 1, wherein: The third preset value is 1400-1600 Guass.

7. The method for growing a crystal rod according to claim 1, wherein: Also includes: The position of the strongest Gaussian surface is adjusted so that the first distance is always smaller than the first preset value during the crystal pulling process.

8. The method for growing a crystal rod according to claim 1, wherein: Also includes: The position of the zero magnetic surface is adjusted so that during the crystal pulling process, the position of the zero magnetic surface is always located at the R arc position of the crucible.

9. A crystal ingot growing device, used to implement the crystal ingot growing method according to any one of claims 1 to 8, comprising: Furnace body; A crucible, located in the furnace body, containing molten silicon; A horizontal magnetic field generating structure is arranged at the periphery of the furnace body and is used to output a horizontal magnetic field to the crucible; The cusp magnetic field generating structure is arranged at the periphery of the furnace body and is used to output a cusp magnetic field to the crucible. The cusp magnetic field generating structure is located on the side of the horizontal magnetic field generating structure away from the top of the furnace body.

10. The crystal ingot growing device according to claim 9, wherein: Also includes: The first regulating structure is used to control the movement of the horizontal magnetic field generating structure in the axial direction of the crystal rod, so that during the crystal pulling process, the distance between the strongest Gaussian surface of the horizontal magnetic field and the liquid surface of the silicon solution is less than a first preset value; The second regulating structure is used to control the movement of the cusp magnetic field generating structure in the axial direction of the crystal rod, so that during the crystal pulling process, the zero magnetic plane of the cusp magnetic field is always located at the R-arc portion of the crucible.

Images