A method for melting fine solid particles in silicon melt and a method for growing single crystal silicon

Abstract

The present application provides a method for melting fine solid particles in a silicon melt and a method for growing single crystal silicon, comprising: placing silicon material in a crucible of a single crystal furnace; heating the crucible to melt the silicon material into a silicon melt; after the silicon material is melted, applying a first magnetic field to the surface area of ​​the silicon melt to eliminate the fine solid particles in the silicon melt. After the silicon material is melted, the present application applies a magnetic field to the surface area of ​​the silicon melt to suppress the convection of the silicon melt, and promote the fine solid particles in the silicon melt to react with the silicon melt to form a volatile object that evaporates outside the silicon melt, so that the subsequent single crystal silicon growth process is more stable, the risk of single crystal silicon broken edges caused by fine solid particles is reduced, and the yield of single crystal silicon products is improved.

Description

Technical Field

[0001] The present application relates to the field of semiconductor technology, and in particular to a method for melting fine solid particles in a silicon melt and a method for growing single crystal silicon. Background Art

[0002] The Czochralski method (CZ method for short) is the main method for growing semiconductor single crystal silicon. The Czochralski method growth process of single crystal silicon includes processes such as charging, melting, seeding, shouldering, equal diameter growth, and finishing. The main process is to load the block polysilicon raw material into a quartz crucible, heat the polysilicon raw material to melt it into silicon melt in the quartz crucible, immerse the seed crystal in the silicon melt contained in the crucible, and pull the seed crystal while rotating the seed crystal and the crucible, so as to carry out seeding, shouldering, equal diameter growth, finishing and cooling at the lower end of the seed crystal in sequence to obtain a single silicon crystal rod.

[0003] Loading is a necessary process for the growth of single crystal silicon. However, when loading bulk polysilicon raw materials into the quartz crucible, the collision between the polysilicon raw materials and the wall of the quartz crucible is inevitable, forming fine quartz particles. Due to the high melting point of quartz particles, after the polysilicon raw materials are melted into liquid, some fine quartz particles are still suspended in the silicon melt. When single crystal silicon grows in equal diameters, once the fine quartz particles drift to the growth interface in the convection of the silicon melt, it will immediately cause the collapse of the single crystal silicon structure (called "broken edge"), thereby reducing the yield of single crystal silicon products.

[0004] Therefore, improvements are needed to at least partially solve the above problems. Summary of the invention

[0005] A series of simplified concepts are introduced in the Summary of the Invention section, which will be further described in detail in the Detailed Description of the Invention section. The Summary of the Invention section of this application does not mean to attempt to define the key features and essential technical features of the claimed technical solution, nor does it mean to attempt to determine the scope of protection of the claimed technical solution.

[0006] In response to the current problems, an embodiment of the present application provides, on the one hand, a method for melting fine solid particles in a silicon melt, comprising: placing silicon material in a crucible of a single crystal furnace and heating the crucible to melt the silicon material into a silicon melt; after the silicon material is melted, applying a first magnetic field to a surface area of ​​the silicon melt to eliminate the fine solid particles in the silicon melt.

[0007] Exemplarily, before applying the first magnetic field to the surface area of ​​the silicon melt, the method further includes adjusting the power of the heater to be within a preset deviation range of the seeding power, wherein the preset deviation range is 80%-120%.

[0008] Exemplarily, after applying the first magnetic field to the surface area of ​​the silicon melt for a first predetermined time, the first magnetic field is turned off.

[0009] Exemplarily, after the first magnetic field is turned off for a second predetermined time, the above steps of turning on and off the first magnetic field are repeated 1-4 times.

[0010] Exemplarily, the first predetermined time is 20 minutes to 60 minutes, and the second predetermined time is 40% to 60% of the first predetermined time.

[0011] Exemplarily, the magnetic field strength of the first magnetic field is 2000 guass-5000 guass.

[0012] Exemplarily, the first magnetic field is a horizontal superconducting magnetic field, and the magnetic flux lines of the horizontal superconducting magnetic field are parallel to the surface of the silicon melt.

[0013] Exemplarily, the central intensity of the horizontal superconducting magnetic field is located within a preset distance range above the surface position of the silicon melt, wherein the preset distance range is 0 mm-200 mm.

[0014] Exemplarily, the fine solid particles include fine silicon oxide particles.

[0015] On the other hand, the present application provides a method for growing single crystal silicon, including the aforementioned melting method.

[0016] The present application provides a method for melting fine solid particles in a silicon melt and a method for growing single crystal silicon. After the silicon material is melted, a magnetic field is applied to the surface area of ​​the silicon melt to suppress the convection of the silicon melt, thereby causing the fine solid particles in the silicon melt to react with the silicon melt to form volatile substances that evaporate out of the silicon melt, thereby making the subsequent single crystal silicon growth process more stable, reducing the risk of single crystal silicon edge breakage caused by fine solid particles, and improving the yield of single crystal silicon products. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] By describing the embodiments of the present application in more detail in conjunction with the accompanying drawings, the above and other purposes, features and advantages of the present application will become more apparent. The accompanying drawings are used to provide a further understanding of the embodiments of the present application and constitute a part of the specification. Together with the embodiments of the present application, they are used to explain the present application and do not constitute a limitation of the present application. In the accompanying drawings, the same reference numerals generally represent the same components or steps.

[0018] In the attached figure:

[0019] Figure 1 A flow chart showing a method for melting fine solid particles in a silicon melt according to an exemplary embodiment of the present application is shown;

[0020] Figure 2 A schematic structural diagram of a single crystal furnace according to an exemplary embodiment of the present application is shown;

[0021] Figure 3 A schematic diagram showing a magnetic field in a surface area of ​​a silicon melt according to an exemplary embodiment of the present application;

[0022] Figure 4 A schematic diagram showing a magnetic field and a heater power according to an exemplary embodiment of the present application is shown. DETAILED DESCRIPTION

[0023] In the following description, a large number of specific details are provided to provide a more thorough understanding of the present application. However, it is apparent to those skilled in the art that the present invention can be implemented without one or more of these details. In other examples, in order to avoid confusion with the present invention, some technical features well known in the art are not described.

[0024] It should be understood that the present application can be implemented in different forms and should not be construed as being limited to the embodiments presented herein. On the contrary, providing these embodiments will make the disclosure thorough and complete, and fully convey the scope of the present invention to those skilled in the art. In the accompanying drawings, the sizes and relative sizes of layers and regions may be exaggerated for clarity. The same reference numerals throughout represent the same elements.

[0025] It should be understood that when an element or layer is referred to as being "on, adjacent to, connected to or coupled to other elements or layers, it may be directly on, adjacent to, connected to or coupled to other elements or layers, or there may be intervening elements or layers. In contrast, when an element is referred to as being "directly on, directly adjacent to, directly connected to or directly coupled to other elements or layers, there may be no intervening elements or layers. It should be understood that, although the terms first, second, third, etc. may be used to describe various elements, components, regions, layers and / or parts, these elements, components, regions, layers and / or parts should not be limited by these terms. These terms are only used to distinguish one element, component, region, layer or part from another element, component, region, layer or part. Therefore, without departing from the teachings of the present invention, the first element, component, region, layer or part discussed below may be represented as a second element, component, region, layer or part.

[0026] Spatially relative terms such as "under," "below," "below," "under," "above," "above," etc., may be used herein for ease of description to describe the relationship of an element or feature shown in the figures to other elements or features. It should be understood that in addition to the orientations shown in the figures, the spatially relative terms are intended to include different orientations of the device in use and operation. For example, if the device in the accompanying drawings is flipped, then the elements or features described as "under other elements" or "under" or "under" will be oriented as "on" the other elements or features. Therefore, the exemplary terms "under" and "under" may include both upper and lower orientations. The device may be oriented otherwise (rotated 90 degrees or other orientations) and the spatial descriptors used herein are interpreted accordingly.

[0027] The purpose of the terms used herein is only to describe specific embodiments and is not intended to be limiting of the present invention. When used herein, the singular forms "one", "an" and "said / the" are also intended to include plural forms, unless the context clearly indicates otherwise. It should also be understood that the terms "consisting of" and / or "comprising", when used in this specification, determine the presence of the features, integers, steps, operations, elements and / or parts, but do not exclude the presence or addition of one or more other features, integers, steps, operations, elements, parts and / or groups. When used herein, the term "and / or" includes any and all combinations of the relevant listed items.

[0028] Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art of this application. It will also be understood that terms such as those defined in commonly used dictionaries should be understood to have a meaning consistent with their meaning in the context of the relevant art and / or this specification, and should not be interpreted in an ideal or overly formal sense unless expressly defined as such herein.

[0029] In order to thoroughly understand the present application, detailed steps and structures will be presented in the following description to illustrate the technical solution proposed by the present application. The preferred embodiments of the present application are described in detail below, but in addition to these detailed descriptions, the present application may also have other implementations.

[0030] When growing silicon single crystals by the Czochralski method, silicon material melts into silicon melt, and the melting point of silicon melt is 1420 degrees Celsius. During the charging process, the block polysilicon raw material is placed in the quartz crucible, and the collision between the polysilicon raw material and the wall of the quartz crucible is inevitable, forming fine solid particles (for example, silicon oxide particles), and the melting point of the fine solid particles is above 1600 degrees Celsius. However, after the silicon material is melted, the temperature of the silicon melt is difficult to rise to the melting point of impurities such as fine solid particles under natural convection conditions, and the power of the heater needs to be reduced after the silicon material is completed to avoid high temperature baking of the quartz crucible, which causes the quartz crucible to soften and deform, making it difficult to crystallize single crystal silicon. When the quartz crucible is severely deformed, the growth process of single crystal silicon will be interrupted, and a large amount of silicon material will remain in the quartz crucible and solidify, causing significant economic losses such as damage to the silicon material and thermal field components. Therefore, some fine solid particles are still suspended in the silicon melt. During the subsequent equal-diameter growth of single crystal silicon, once the remaining fine solid particles drift to the growth interface in the melt convection, they will immediately cause the collapse of the single crystal silicon lattice structure (called "broken edge"), ending the growth of single crystal silicon and reducing the yield of single crystal silicon products.

[0031] In the related art, when the edge breaking occurs in the early stage of equal diameter growth, the heater power is increased to melt the grown crystal rod again, and the crystal is seeded, shouldered, and equal diameter growth is performed again, which increases the overall process time and reduces the production efficiency. When the edge breaking occurs in the late stage of equal diameter growth, the silicon material in the silicon melt is usually continued to be pulled and grown in the form of polycrystalline silicon, which reduces the product qualification rate of single crystal silicon.

[0032] Therefore, in view of the existence of the above-mentioned technical problems, the present application proposes a method for melting fine solid particles in silicon melt, comprising:

[0033] In step S1: placing silicon material in a crucible of a single crystal furnace;

[0034] In step S2: heating the crucible to melt the silicon material into a silicon melt;

[0035] In step S3: after the silicon material is melted, a first magnetic field is applied to the surface area of ​​the silicon melt to eliminate fine solid particles in the silicon melt.

[0036] The present application provides a method for melting fine solid particles in a silicon melt. After the silicon material is melted, a magnetic field is applied to the surface area of ​​the silicon melt to suppress the convection of the silicon melt, thereby prompting the fine solid particles in the silicon melt to react with the silicon melt to form volatile substances that evaporate out of the silicon melt, thereby making the subsequent single crystal silicon growth process more stable, reducing the risk of single crystal silicon edge breakage caused by fine solid particles, and improving the yield of single crystal silicon products.

[0037] Embodiment 1

[0038] Below, reference Figure 1-Figure 4The method for melting fine solid particles in silicon melt of the present application is described in detail, wherein: Figure 1 A flow chart showing a method for melting fine solid particles in a silicon melt according to an exemplary embodiment of the present application is shown. Figure 2 The schematic diagram of the structure of a single crystal furnace according to an exemplary embodiment of the present application is shown. Figure 3 A schematic diagram showing a magnetic field in a surface area of ​​a silicon melt according to an exemplary embodiment of the present application is shown. Figure 4 A schematic diagram showing the magnetic field and the power of the heater according to an exemplary embodiment of the present application is shown.

[0039] First refer to Figure 2 , Figure 2 The single crystal furnace shown is used to grow single crystal silicon by adopting the Czochralski method, and comprises at least a furnace body 201 , a crucible 202 , a heater 203 and a magnetic field applying device 204 .

[0040] In one example, the crucible 202 may include a quartz crucible 2021 and a graphite crucible 2022. The quartz crucible 2021 is used to hold silicon material, such as polycrystalline silicon, in which the silicon material is heated to form a silicon melt 205. The graphite crucible 2022 is wrapped around the outside of the quartz crucible 2021 to provide support for the quartz crucible 2021 during the heating process. The heater 203 is disposed on the outside of the graphite crucible 2022 to provide a heat source.

[0041] Second reference Figure 3 , a magnetic field is applied near the surface area of ​​the silicon melt 205 to hinder the convection of the silicon melt 205 surface area. According to the basic principle of heat transfer, the "thermal resistance" of the stagnant silicon melt is much greater than that of the convective silicon melt, which is equivalent to adding an insulation "lid" to the silicon melt 205. Under the same thermal field conditions, the temperature of the silicon melt 205 is higher, which prompts the fine solid particles 206 to react quickly with the silicon melt 205 and the trace carbon elements therein to form volatiles (such as silicon oxide, carbon monoxide, etc.) that evaporate to the outside of the silicon melt 205. Therefore, the single crystal furnace also includes a magnetic field applying device 204 arranged on the outside of the furnace body 201 to apply a magnetic field to the silicon melt 205 in the crucible 202.

[0042] Continue as Figure 3 As shown, the magnetic flux lines of the magnetic field applied by the magnetic field applying device 204 pass through the surface of the silicon melt 205 in the crucible 202 from one end to the other end in parallel (see Figure 3 Because the liquid silicon melt is conductive, under the action of the magnetic field, the Lorentz force generated in the silicon melt suppresses the natural convection of the silicon melt.

[0043] For example, refer to Figure 1 The method for melting fine solid particles in silicon melt of the present application comprises the following steps:

[0044] First, step S1 is performed to place silicon material in a crucible of a single crystal furnace.

[0045] In one example, if Figure 2 As shown, when growing single crystal silicon, firstly, silicon material, such as polycrystalline silicon, is placed in the crucible 202 of the single crystal furnace. Specifically, firstly, the polycrystalline silicon raw material is loaded into the quartz crucible 2021 and installed in the graphite crucible 2022; then, the furnace cover and the auxiliary chamber of the single crystal furnace are closed and vacuumized, and a protective gas, such as argon, is filled into the single crystal furnace. Exemplarily, the quartz crucible 2021 can be 32 inches or other suitable sizes, which are not specifically limited.

[0046] Then, step S2 is performed to heat the crucible to melt the silicon material into silicon melt.

[0047] In one example, the crucible 202 is heated to melt the silicon material into a silicon melt 205. Specifically, after the protective gas is filled into the single crystal furnace, the heater 203 is turned on to heat the silicon material to a temperature above the melting temperature, so that the silicon material is melted into the silicon melt 205. The heater 203 may include a side heater and a bottom heater (such as Figure 2 Only the side heaters are shown, and the bottom heater is not shown). The side heaters are located on both sides of the outside of the graphite crucible 2022, and the bottom heater is located at the bottom of the outside of the graphite crucible 2022.

[0048] Finally, step S3 is performed, in which, after the silicon material is melted, a first magnetic field is applied to the surface area of ​​the silicon melt to eliminate fine solid particles in the silicon melt.

[0049] In one example, if Figure 4 After the silicon material is melted, before applying the first magnetic field to the surface area of ​​the silicon melt 205, the power of the heater 203 is adjusted to the preset deviation range of the seeding power, wherein the preset deviation range is 80%-120%. Specifically, as the temperature of the thermal field in the single crystal furnace rises, the block silicon raw material in the quartz crucible 2021 gradually melts into liquid (that is, the silicon melt 205). After all the silicon material is melted, the side heater is reduced to the seeding power, and the bottom heater is reduced to 20% of the melting silicon material, so that the power of the heater 203 is adjusted to the preset deviation range of the seeding power, which is 80%-120%. For example, the power of the heater 203 is adjusted to 80%, 90%, 100%, 110% or 120% of the seeding power.

[0050] In one example, a first magnetic field is applied to the surface area of ​​the silicon melt 205 and the first magnetic field lasts for a first predetermined time, and then the first magnetic field is turned off. After the silicon material is melted, the temperature of the silicon melt 205 is difficult to rise to the melting point temperature of impurities such as fine solid particles 206 under natural convection. Therefore, some fine solid particles 206 are still suspended in the silicon melt 205, which will affect the yield of subsequent single crystal silicon products. Since the liquid silicon melt 205 is conductive, under the action of the magnetic field, the Lorentz force generated in the silicon melt 205 inhibits the natural convection of the silicon melt 205. According to the basic principles of heat transfer, the thermal resistance of the stagnant silicon melt is much greater than that of the convective silicon melt, which is equivalent to adding a heat preservation "pot cover" to the silicon melt 205, so that under the same thermal field conditions, the temperature of the silicon melt 205 is higher, which prompts the fine solid particles 206 to react quickly with the silicon melt 205 and the trace carbon elements therein to form volatile substances (such as silicon oxide, carbon monoxide, etc.) that evaporate to the outside of the silicon melt 205 and are degraded. Exemplarily, a first magnetic field is applied to the surface area of ​​the silicon melt 205 and the first magnetic field is maintained for a first predetermined time so that the fine solid particles 206 react with the silicon melt 205 and are fully dissolved. The first predetermined time (i.e., the time when the magnetic field is turned on) can be 20min-60min, for example 20min, 30min, 40min, 55min or 60min, etc.

[0051] In one example, the magnetic field strength of the first magnetic field is 2000 guass-5000 guass, such as 2000 guass, 2500 guass, 3000 guass, 4000 guass, 4500 guass or 5000 guass, etc. In this embodiment, the magnetic field strength of the first magnetic field is 3000 gauss. In other examples, the magnetic field strength of the first magnetic field can also be 5000 guass or other suitable magnetic field strengths, which is not specifically limited.

[0052] In one example, if Figure 3As shown, the first magnetic field is a horizontal superconducting magnetic field, and the magnetic flux lines of the horizontal superconducting magnetic field are parallel to the surface of the silicon melt 205. The central strength of the horizontal superconducting magnetic field is located within a preset distance range above the surface position of the silicon melt 205, and the preset distance range is 0mm-200mm, such as 0mm, 50mm, 100mm, 150mm, 180mm or 200mm. Since the central strength of the horizontal superconducting magnetic field will affect the convection pattern and temperature distribution in the molten silicon 205, setting the position of the central strength of the horizontal superconducting magnetic field within the preset distance range above the surface position of the silicon melt 205 is equivalent to adding a heat preservation "lid" to the silicon melt 205, so that under the same thermal field conditions, the temperature of the silicon melt 205 is higher, which promotes the fine solid particles 206 to react quickly with the silicon melt 205 and the trace carbon elements therein to form volatiles (such as silicon oxide, carbon monoxide, etc.) that are volatilized and discharged outside the silicon melt 205. Therefore, when single crystal silicon is subsequently grown, it is necessary to set a suitable position of the central strength of the horizontal superconducting magnetic field to improve the quality of single crystal silicon products.

[0053] In one example, after applying the first magnetic field to the surface area of ​​the silicon melt 205 for a first predetermined time, the first magnetic field is turned off, and the power of the heater 203 is increased by 0%-30% and continued for a second predetermined time. For example, the power of the heater 203 at this time can be maintained (that is, the power of the heater 203 is increased by 0%), or the power of the heater 203 at this time can be increased by 10%, 15%, 20%, 25% or 30%, etc., which is not specifically limited. For example, the second predetermined time is 40%-60% of the first predetermined time (that is, the time of turning on the magnetic field). For example, when the first predetermined time is 40 minutes, the second predetermined time can be 16 minutes, 18 minutes, 20 minutes, 22 minutes or 24 minutes, etc.; when the first predetermined time is 60 minutes, the second predetermined time can be 24 minutes, 28 minutes, 32 minutes, 30 minutes or 34 minutes, etc. In this embodiment, after the first magnetic field is turned on and maintained for 60 minutes, the superconducting magnetic field is turned off (that is, the magnetic field strength is 0), and the power of the heater 203 is maintained for 30 minutes. In other examples, after the first magnetic field is turned on and maintained for 60 minutes, the superconducting magnetic field is turned off (that is, the magnetic field strength is 0), and the power of the heater 203 is increased by 30% and maintained for 30 minutes, and there is no specific limitation on this. By applying a magnetic field to the surface area of ​​the silicon melt 205, the convection of the silicon melt in this part is suppressed, and the fine solid particles 206 in the silicon melt 205 are caused to react with the silicon melt to form volatiles, which are degraded. In the subsequent isodiametric growth process, the risk of solid microparticles 206 being free to the growth interface to destroy the single crystal silicon structure and cause broken edges is reduced.

[0054] In one example, the fine solid particles 206 include fine silicon oxide particles. For example, when the silicon material is loaded into the quartz crucible 2021, the silicon material inevitably collides with the wall of the quartz crucible 2021, forming fine solid particles 206, such as fine silicon oxide particles.

[0055] In one example, after the first magnetic field is turned off for a second predetermined time, the above steps of turning on and off the first magnetic field are repeated 1-4 times. After the above-mentioned opening and closing of the first magnetic field are completed, the above-mentioned process steps of turning on and off the first magnetic field are continued to be repeated to fully eliminate the fine solid particles 206 remaining in the silicon melt 205. Specifically, after the above-mentioned opening and closing of the first magnetic field (that is, the first opening and closing of the first magnetic field) are completed, the first magnetic field is turned on again, the magnetic field strength is set to 3000 gauss, and after the first predetermined time is continued, the first magnetic field is turned off, and the power of the heater 203 is increased by 0%-30%, and continued for the second predetermined time, so that the second opening and closing of the first magnetic field is completed, and then the process steps of turning on and off the first magnetic field can be continued. By turning on and off the first magnetic field multiple times to fully eliminate the fine solid particles 206 in the silicon melt 205, the risk of the fine solid particles 206 in the silicon melt 205 being free to the growth interface and causing broken edges during the subsequent equal-diameter growth process is reduced. At the same time, by repeatedly opening and closing the magnetic field, the microbubbles in the silicon melt 205 and the inner wall of the quartz crucible 2021 react quickly with the silicon melt 205 and the trace carbon elements therein to form volatile substances such as silicon oxide or silicon dioxide, which are discharged out of the silicon melt 205, thereby reducing the probability of occurrence of micropores (Airpockets) in the crystal, thereby improving the Airpocket yield, and thus improving the product yield of single crystal silicon, shortening the process time, and improving production efficiency.

[0056] It should be noted that after the fine solid particles 206 in the silicon melt 205 are eliminated, the temperature of the heater 203 is adjusted to stabilize the temperature, and subsequent conventional semiconductor single crystal silicon growth processes such as seeding, shoulder release, equal diameter growth, finishing, and cooling are continued.

[0057] In summary, the method for melting fine solid particles in silicon melt provided in the present application applies a magnetic field to the surface area of ​​the silicon melt after the silicon material is melted, thereby suppressing the convection of the silicon melt, causing the fine solid particles in the silicon melt to react with the silicon melt to form volatile substances that evaporate out of the silicon melt, thereby making the subsequent single crystal silicon growth process more stable, reducing the risk of single crystal silicon edge breakage caused by fine solid particles, and improving the yield of single crystal silicon products.

[0058] The present application also provides a single crystal silicon growth method, which includes the method for melting fine solid particles in the silicon melt described in Example 1, so as to realize the aforementioned melting of fine solid particles in the silicon melt in the single crystal silicon growth process.

[0059] Although example embodiments have been described herein with reference to the accompanying drawings, it should be understood that the above example embodiments are merely exemplary and are not intended to limit the scope of the present application to this. Those of ordinary skill in the art may make various changes and modifications therein without departing from the scope and spirit of the present application. All these changes and modifications are intended to be included within the scope of the present application as required by the appended claims.

[0060] In the description provided herein, a large number of specific details are described. However, it is understood that the embodiments of the present application can be practiced without these specific details. In some instances, well-known methods, structures and techniques are not shown in detail so as not to obscure the understanding of this description.

[0061] Similarly, it should be understood that in order to streamline the present application and help understand one or more of the various inventive aspects, in the description of the exemplary embodiments of the present application, the various features of the present application are sometimes grouped together into a single embodiment, figure, or description thereof. However, the method of the present application should not be interpreted as reflecting the following intention: the claimed application requires more features than the features clearly stated in each claim. More specifically, as reflected in the corresponding claims, the inventive point is that the corresponding technical problem can be solved with features less than all the features of a single disclosed embodiment. Therefore, the claims following the specific embodiment are hereby explicitly incorporated into the specific embodiment, wherein each claim itself serves as a separate embodiment of the present application.

[0062] It will be understood by those skilled in the art that, except for mutually exclusive features, all features disclosed in this specification (including the accompanying claims, abstracts and drawings) and all processes or units of any method or device disclosed in this specification may be combined in any combination. Unless otherwise expressly stated, each feature disclosed in this specification (including the accompanying claims, abstracts and drawings) may be replaced by an alternative feature that provides the same, equivalent or similar purpose.

[0063] In addition, those skilled in the art will appreciate that, although some embodiments herein include certain features included in other embodiments but not other features, the combination of features of different embodiments is meant to be within the scope of the present application and form different embodiments. For example, in the claims, any one of the claimed embodiments may be used in any combination.

[0064] The above is only a specific implementation or description of a specific implementation of the present application, and the protection scope of the present application is not limited thereto. Any technician familiar with the technical field can easily think of changes or substitutions within the technical scope disclosed in the present application, which should be included in the protection scope of the present application. The protection scope of the present application shall be based on the protection scope of the claims.

Claims

1. A method for melting fine solid particles in silicon melt, characterized in that: include: Placing silicon material in a crucible of a single crystal furnace; heating the crucible to melt the silicon material into a silicon melt; After the silicon material is melted, a first magnetic field is applied to the surface area of ​​the silicon melt to eliminate fine solid particles in the silicon melt.

2. The method for melting according to claim 1, characterized in that: Before applying the first magnetic field to the surface area of ​​the silicon melt, the method further includes adjusting the power of the heater to be within a preset deviation range of the seeding power, wherein the preset deviation range is 80%-120%.

3. The pin melting method according to claim 1, characterized in that: After applying the first magnetic field to the surface area of ​​the silicon melt for a first predetermined time, the first magnetic field is turned off.

4. The pin melting method according to claim 3, characterized in that: After the first magnetic field is turned off for a second predetermined time, the above steps 1-4 of turning on and off the first magnetic field are repeated for multiple times.

5. The pin melting method according to claim 4, characterized in that: The first scheduled time is 20 minutes to 60 minutes, and the second scheduled time is 40% to 60% of the first scheduled time.

6. The pin melting method according to claim 1, characterized in that: The magnetic field strength of the first magnetic field is 2000 guass-5000 guass.

7. The pin melting method according to claim 6, characterized in that: The first magnetic field is a horizontal superconducting magnetic field, and the magnetic flux lines of the horizontal superconducting magnetic field are parallel to the surface of the silicon melt.

8. The pin melting method according to claim 7, characterized in that: The central intensity of the horizontal superconducting magnetic field is located within a preset distance range above the surface position of the silicon melt, wherein the preset distance range is 0 mm-200 mm.

9. The pin melting method according to claim 1, characterized in that: The fine solid particles include fine silicon oxide particles.

10. A method for growing single crystal silicon, characterized in that: The method comprises the pin melting method as claimed in any one of claims 1 to 9.

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