Single crystal furnace quartz crucible transverse magnetic field intensity distribution measuring disc and measuring method

Abstract

The application discloses a single-crystal furnace quartz crucible transverse magnetic field strength distribution measuring disc and a measuring method. The measuring disc comprises a disc body, which is disc-shaped, and is provided with a positioning structure at the bottom for coaxial limiting installation with a single-crystal furnace crucible handle; a magnetic pole mark is arranged on the disc body and used for aligning with the N-pole direction and the S-pole direction of the transverse magnetic field; a plurality of concentric circle marks are arranged on the upper surface of the disc body with the center of the disc body as the center and different diameters as the radii, and each concentric circle mark corresponds to a standard diameter of the edge of a quartz crucible or the edge of a crystal growth solid-liquid interface; and an angle division line extends radially from the center of the disc body to the edge of the disc body and equally divides the circumference of the disc body with a preset central angle. The application replaces a multi-axis motor driving device with a passive disc, realizes fast concentric positioning and magnetic pole calibration, and makes the measuring point position systematic and overcomes the magnetic field directionality problem.

Description

Technical Field

[0001] This invention relates to the field of magnetic field measurement technology for single crystal furnaces, specifically to a measuring dial and method for measuring the transverse magnetic field intensity distribution of a quartz crucible in a single crystal furnace. Background Technology

[0002] Silicon single crystals are generally manufactured using the Czochralski method. This involves placing polycrystalline silicon raw material in a quartz crucible within a single-crystal furnace, heating and melting the polycrystalline silicon using a graphite heater, and then using a seed crystal to grow a silicon single crystal by rotating it at a certain speed. Because the Czochralski method involves thermal convection in the melt during crystal growth, and uneven distribution of trace impurities affects the crystal growth quality, the Czechralski method (MCZ Czochralski method) using a magnetic field has emerged. Introducing a magnetic field effectively suppresses thermal convection in molten silicon due to the magnetic field lines. Currently, the mainstream magnetic field methods include transverse magnetic fields and hook-shaped magnetic fields (Cusp magnetic fields). In transverse magnetic fields, the magnetic field lines horizontally traverse the crucible, with high field strength near the left and right pole regions of the single-crystal furnace, rapidly decreasing towards the center, resulting in a large radial gradient and uneven Lorentz force distribution within the crucible. In the axial direction, the effective magnetic field is concentrated only in a narrow axial region between the magnetic poles, with uneven field strength distribution in the upper and lower parts of the crucible. Therefore, a comprehensive understanding of the magnetic induction intensity distribution at different locations inside the quartz crucible is necessary to design a matching crystal growth process.

[0003] Currently, the testing of magnetic induction intensity using a gaussmeter is usually done handheld. Due to the large number of measurement points, manual positioning is essential for accurate measurement, leading to significant errors. Several solutions have been proposed to address the positioning problem. Chinese patent CN112904245A discloses a single-crystal furnace magnetic field strength measuring device, employing a circular support with a three-axis CNC motor to drive a probe in three-dimensional motion (rotation, Z-axis lifting, and X-axis translation). Hall effect sensors and a computer enable automatic positioning and measurement of the probe. Chinese patent CN121325057A discloses a scheme using upper / lower support plates and a planetary rotation mechanism to drive an eccentric probe for measuring magnetic field strength. Chinese patent CN221406007U discloses a method using a probe fixing device to clamp the probe, and using an in-furnace and out-of-furnace measuring rod to move the probe through the measurement points.

[0004] However, the aforementioned existing technical solutions all employ complex mechanical transmission and multi-axis motor drive structures, resulting in large equipment size and high cost. Furthermore, they are primarily designed for three-dimensional point traversal in general spaces and cannot be directly adapted to circular, axisymmetric magnetic field measurement scenarios such as single-crystal furnace quartz crucibles. In measuring the transverse magnetic field at the solid-liquid interface of crystal growth and around the crucible, these devices struggle to quickly achieve concentric positioning with the crucible, alignment of magnetic poles, and equal division of circumferential angles. They cannot intuitively and conveniently obtain the magnetic field distribution at different circumferential angles and radial positions of the crucible. Simultaneously, these devices lack a standardized measurement benchmark matching the crucible diameter, preventing rapid positioning of measurement points at different radii. Moreover, in symmetrical transverse magnetic fields, magnetic induction intensity exhibits significant directionality: the magnetic field distribution is symmetrical about the geometric center. The BZ component of the magnetic field intensity (i.e., the component of the magnetic induction intensity vector B along the Z-axis) increases with distance from the center point in the Z-direction, but decreases with distance from the center point in the X and Y directions. The maximum value can only be measured when the probe's sensing surface is perpendicular to the magnetic field lines. Under the above fixed-posture measurement method, the probe angle cannot be adaptively adjusted, making it difficult to capture the true maximum magnetic induction intensity at each measurement point, and the representativeness of the measurement results is insufficient.

[0005] Therefore, in the field of crystal growth, it is still difficult to meet the requirements for accurate, efficient and intuitive detection of magnetic field uniformity when rapidly calibrating and measuring the transverse magnetic field inside the quartz crucible of a single crystal furnace. Summary of the Invention

[0006] This application provides a measuring dial and method for measuring the transverse magnetic field intensity distribution of a single-crystal furnace quartz crucible, which at least solves the problems of complex structure, high cost, inability to quickly adapt to the circular cross section of the crucible for concentric positioning and magnetic pole calibration, and difficulty in capturing the true maximum magnetic induction intensity of each measuring point when the probe angle is fixed in the prior art.

[0007] In a first aspect, this application provides a transverse magnetic field intensity distribution measuring dial for a single-crystal furnace quartz crucible, comprising: The dial body is disc-shaped, and its bottom is provided with a positioning structure for coaxial positioning and limiting installation with the crucible support handle of the single crystal furnace; Magnetic pole markings are located on the dial body and are used to align with the N and S pole directions of the transverse magnetic field. Multiple concentric rings are arranged on the upper surface of the dial body with the center of the dial body as the center and different diameters as the radius. Each concentric ring corresponds to a standard diameter of the edge of a quartz crucible or the edge of the solid-liquid interface of crystal growth. An angular dividing line extends radially from the center of the dial body to the edge of the dial body, and divides the circumference of the dial body equally with a preset central angle. The intersection of the angular dividing line and the concentric ring mark forms a grid of magnetic field measurement points.

[0008] Optionally, the positioning structure is a positioning step, the outer diameter and height of which match the inner diameter and depth of the top step of the crucible handle, respectively, to achieve coaxial positioning and limiting installation.

[0009] Optionally, the angle dividing line is divided into 15° central angles along the circumference of the dial body, so that the circumference of the dial body is divided into twenty-four angle intervals.

[0010] Optionally, the number of concentric ring markers is at least two, and includes at least a first concentric ring marker corresponding to the diameter of the quartz crucible and a second concentric ring marker corresponding to the edge diameter of the solid-liquid interface during crystal growth.

[0011] Optionally, the magnetic pole markings are the letters N and S printed or engraved on the upper surface of the dial body, and the letters N and S are arranged opposite each other along the diameter direction of the dial body.

[0012] Secondly, this application also provides a method for measuring the transverse magnetic field intensity distribution of a single-crystal furnace quartz crucible, using the measuring dial provided in the first aspect above, including: The measuring dial is coaxially positioned and mounted on the crucible handle of the single crystal furnace using the positioning structure, so that the center of the measuring dial coincides with the rotation axis of the crucible handle. Adjust the vertical position of the measuring dial so that the upper surface of the measuring dial is flush with the central plane of the transverse magnetic field, and the central plane coincides with the position of the molten silicon surface during crystal growth; Rotate the crucible handle to drive the measuring dial to rotate around the rotation axis of the crucible handle, so that the magnetic pole markings are respectively aligned with the N pole direction and S pole direction of the transverse magnetic field; Determine the first concentric ring mark corresponding to the edge of the quartz crucible to be tested and the second concentric ring mark corresponding to the edge of the solid-liquid interface of the crystal growth. Determine the intersection of the first concentric ring mark, the second concentric ring mark, and the remaining concentric ring marks between them with the angle dividing line as the measurement point. At each of the measurement points, the maximum magnetic induction intensity value is obtained by taking the N-pole direction to the S-pole direction determined by the magnetic pole marking as the reference direction.

[0013] Optionally, the step of obtaining the maximum magnetic flux density value at each of the measurement points includes: measuring the magnetic flux density at each of the measurement points with a gaussmeter probe, and finely adjusting the angle of the gaussmeter probe to obtain the maximum magnetic flux density value at that measurement point.

[0014] Optionally, the measurement method further includes: after completing the measurement of all the measurement points on the current horizontal plane, moving the measuring dial vertically downward by a preset distance, and repeating the steps of determining the measurement points and obtaining the maximum magnetic induction intensity value on the new horizontal plane to obtain the magnetic field intensity distribution of different height planes inside the quartz crucible.

[0015] Optionally, the preset distance is 50 mm to 100 mm, and the number of times the measuring dial moves downward is determined according to the height of the molten silicon in the quartz crucible and the preset distance.

[0016] Optionally, the measurement method further includes: summarizing the magnetic induction intensity recorded at each measurement point in a data table, calculating the rate of change of magnetic induction intensity in the direction parallel to the magnetic field lines and in the direction perpendicular to the magnetic field lines, and evaluating the uniformity of the transverse magnetic field inside the quartz crucible based on the rate of change.

[0017] Compared with related technologies, the transverse magnetic field intensity distribution measuring dial and method for single-crystal furnace quartz crucibles provided in this application have at least the following technical advantages: A passive dial is used instead of a complex multi-axis motor-driven measuring device. The dial's bottom positioning step engages with the existing crucible support handle of the single-crystal furnace, achieving concentric positioning of the dial and crucible in one step, eliminating the need for additional supports or alignment procedures. The dial has multiple pre-set concentric ring markings and 15° equally spaced angle division lines. These intersect to form a standardized measurement point grid covering the entire cross-section of the crucible's interior. This grid can cover 14-inch to 36-inch quartz crucible sizes commonly used in the semiconductor industry, as well as 4-inch to 12-inch crystal sizes. Furthermore, it can be understood that as the size of the quartz crucible and crystal being measured increases, the measuring dial can be adapted by adding external concentric circles.

[0018] During measurement, the dial is simply mounted on the crucible support handle. The vertical and circumferential positions of the dial are adjusted using the existing crucible lifting and rotating mechanisms of the single crystal furnace, requiring no additional drive device. When acquiring the magnetic induction intensity at each measurement point, the operator can capture the maximum magnetic induction intensity value at that point by finely adjusting the angle of the gaussmeter probe. This overcomes the problem that the magnetic field intensity in a symmetrical transverse magnetic field is directional, making it difficult for a fixed-position probe to measure the true maximum value, thus significantly improving the representativeness of the measurement results. After the measurement is completed, the data from each point are summarized to calculate the rate of change of magnetic induction intensity in the parallel and perpendicular directions, allowing for a quantitative evaluation of the uniformity of the transverse magnetic field.

[0019] Details of one or more embodiments of this application are set forth in the following drawings and description to make other features, objects and advantages of this application more readily apparent. Attached Figure Description

[0020] Figure 1 This is a top view of a measuring dial according to an exemplary embodiment.

[0021] Figure 2 This is a front view of a measuring dial shown according to an exemplary embodiment.

[0022] Figure 3 This is a diagram showing the distribution of transverse magnetic field lines in a symmetrical transverse magnetic field according to an exemplary embodiment.

[0023] Figure 4 This is a front view of the installation of the measuring dial inside a single crystal furnace according to an exemplary embodiment.

[0024] Figure 5 This is a top view illustrating the installation of a measuring dial within a single crystal furnace according to an exemplary embodiment.

[0025] Figure 6 This is a schematic diagram of crystal growth in a single crystal furnace with a transverse magnetic field, according to an exemplary embodiment.

[0026] Figure 7 This is a schematic diagram illustrating the magnetic flux density distribution along the direction of magnetic field lines and perpendicular to the inner wall of an 18-inch quartz crucible according to an exemplary embodiment. Detailed Implementation

[0027] To make the objectives, technical solutions, and advantages of the embodiments of this disclosure clearer, the technical solutions of the embodiments of this disclosure will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this disclosure. All other embodiments obtained by those skilled in the art based on the described embodiments of this disclosure without creative effort are within the scope of protection of this disclosure.

[0028] Unless otherwise defined, the technical or scientific terms used in this disclosure shall have the ordinary meaning understood by one of ordinary skill in the art to which this disclosure pertains. The terms “first,” “second,” and similar terms used in this disclosure do not indicate any order, quantity, or importance, but are merely used to distinguish different components. Terms such as “comprising” or “including” mean that an element or object preceding the word encompasses the elements or objects listed following the word and their equivalents, without excluding other elements or objects. Terms such as “connected” or “linked” are not limited to physical or mechanical connections, but can include electrical connections, whether direct or indirect.

[0029] In related technologies, the measurement of the transverse magnetic field strength of a single crystal furnace relies on a bracket-type measuring device driven by a multi-axis motor. This device is complex in structure, expensive, and lacks a standardized positioning reference that matches the circular cross-section of the crucible, making it impossible to quickly achieve concentric positioning and magnetic pole calibration.

[0030] Based on the above, embodiments of the present invention provide a measuring dial and method for measuring the transverse magnetic field intensity distribution of a single-crystal furnace quartz crucible, which will be described in detail below with reference to specific embodiments and accompanying drawings.

[0031] Example 1 This invention provides a measuring dial. Figure 1 This is a top view of a measuring dial according to an exemplary embodiment. Figure 2 This is a front view of a measuring dial shown according to an exemplary embodiment. Figure 3 This is a diagram illustrating the distribution of transverse magnetic field lines in a symmetrical transverse magnetic field, according to an exemplary embodiment. For example... Figures 1-3 As shown, in a symmetrical transverse magnetic field, the magnetic induction intensity has a significant directionality—the magnetic field distribution is symmetrical about the geometric center. The BZ component of the magnetic field intensity increases with the distance from the center point in the Z direction, and decreases with the distance from the center point in the X and Y directions. The maximum value can only be measured when the probe sensing surface is perpendicular to the magnetic field lines.

[0032] Specifically, the measuring dial 10 includes the dial body 101, positioning steps 102, magnetic pole markings 103, multiple concentric ring markings 104, and angle dividing lines 105.

[0033] The dial body 101 is disc-shaped and can be made of a transparent material (such as acrylic sheet). The bottom of the dial body 101 is provided with a positioning step 102, the outer diameter and height of which precisely match the inner diameter and depth of the top step 202 of the inner support handle of the main furnace chamber 20 of the single crystal furnace. Figure 4 This is a front view of the installation of the measuring dial inside a single crystal furnace according to an exemplary embodiment. Figure 5 This is a top view illustrating the installation of a measuring dial within a single crystal furnace according to an exemplary embodiment. (Refer to...) Figures 4-5 During measurement, the measuring dial 10 is placed on the crucible handle 201, and the positioning step 102 is embedded in the top step 202 of the handle, so that the coaxial limiting installation is achieved in one placement. The center of the measuring dial 10 is automatically aligned with the rotation axis of the crucible handle 201.

[0034] The magnetic pole markings 103 are the letters N and S printed or engraved on the upper surface of the dial body 101, with the letters N and S positioned opposite each other along the diameter of the dial body 101. During measurement, the crucible handle 201 is rotated by the crucible rotation mechanism, which is a standard configuration of the single crystal furnace, causing the measuring dial 10 to rotate so that the N marking is aligned with the N pole 301 of the transverse magnetic field 30, and the S marking is aligned with the S pole 302, thereby establishing a measurement coordinate system on the dial that is consistent with the direction of the magnetic field lines 303.

[0035] Multiple concentric ring markers 104 are positioned on the upper surface of the dial body 101 with different radii centered at the center of the dial body 101. Each concentric ring marker 104 corresponds to a standard diameter of the edge of a quartz crucible or the solid-liquid interface edge of crystal growth—for example, a first concentric ring marker with a diameter of 600 mm corresponds to the diameter of a 24-inch crucible, and a second concentric ring marker with a diameter of 100 mm corresponds to the size of a 4-inch single crystal growth solid-liquid interface; or, for example, a first concentric ring marker with a diameter of 450 mm corresponds to the diameter of an 18-inch crucible, and a second concentric ring marker with a diameter of 100 mm corresponds to the size of a 4-inch single crystal growth solid-liquid interface. Angle dividing lines 105 extend radially from the center of the dial body 101 to the edge, dividing the circumference into twenty-four angular intervals with a central angle of 15°. The intersections of the angle dividing lines 105 and the concentric ring markers 104 form a standardized magnetic field measurement point grid covering the entire cross-section inside the crucible.

[0036] In summary, the measuring dial provided in this embodiment uses positioning steps to achieve rapid coaxial installation with the crucible handle, establishes a measurement coordinate system reference with magnetic pole markings, and establishes a standardized distribution of measurement points with the intersection grid of concentric ring markings and angle dividing lines. The structure is simple, the cost is low, and no additional brackets or alignment procedures are required for installation and positioning.

[0037] Example 2 This invention provides a measurement method using the measuring dial 10 described in Example 1. Figure 7 This is a schematic diagram illustrating the magnetic flux density distribution along the direction of magnetic field lines and perpendicular to the inner wall of an 18-inch quartz crucible, according to an exemplary embodiment. Figures 1-7 As shown, the measurement method includes the following steps: S10, the measuring dial 10 is coaxially positioned and mounted on the crucible handle 201 via the positioning step 102.

[0038] Reference Figures 4-6The specific operation is as follows: Open the furnace cover 207 of the single crystal furnace, and remove the quartz crucible 205, graphite crucible 204, heater 203, and other hot field components from the main furnace chamber 20 of the single crystal furnace, leaving only the crucible handle 201 mounted on the central axis. Place the measuring dial 10 downwards on the crucible handle 201, so that the positioning step 102 at the bottom of the dial body 101 is embedded in the top step 202 of the handle. Because the outer diameter and height of the positioning step 102 precisely match the inner diameter and depth of the top step 202 of the handle, the center of the measuring dial 10 automatically coincides with the rotation axis of the crucible handle 201 after installation, without the need for additional alignment or calibration tools. After installation, the upper surface of the measuring dial 10 becomes the reference plane for subsequent magnetic field measurements.

[0039] S20, adjust the vertical position of the measuring dial 10 so that its upper surface is flush with the center plane of the transverse magnetic field 30.

[0040] Reference Figures 1-6 The transverse magnetic field 30 is generated by symmetrically arranged N poles 301 and S poles 302, with magnetic field lines 303 distributed along the direction from the N poles to the S poles. The central plane of the magnetic field is located at the axial center of the gap between the two magnetic poles, and this plane coincides with the position of the molten silicon surface during crystal growth. The distance from the molten silicon surface to the top of the main furnace chamber 20 of the single crystal furnace is denoted as A (this distance is determined by the single crystal furnace equipment parameters and thermal field configuration). The height of the crucible handle 201 is adjusted using the crucible lifting mechanism, and the distance from the upper surface of the measuring dial 10 to the top of the main furnace chamber 20 of the single crystal furnace is confirmed to be A using a ruler. At this time, the upper surface of the measuring dial 10 is flush with the central plane of the transverse magnetic field 30. The upper surface of the measuring dial 10 is the magnetic field measuring plane.

[0041] S30, rotate the crucible handle 201 to drive the measuring dial 10 to rotate, so that the magnetic pole mark 103 is aligned with the N pole 301 and S pole 302 of the transverse magnetic field 30 respectively.

[0042] Reference Figure 5 The crucible handle 201 is driven to rotate around its axis by a crucible rotation mechanism, and the measuring dial 10 rotates synchronously with the crucible handle 201. Rotation stops when the N mark on the measuring dial 10 aligns with the N pole 301 and the S mark aligns with the S pole 302. This step establishes the correspondence between the measuring coordinate system on the measuring dial 10 and the actual direction of the magnetic field. The direction in which the N mark points to the N pole 301 is the reference direction of the magnetic field lines 303, and the probe direction at each subsequent measurement point will use this as the angular reference.

[0043] S40, determine the measurement points. Identify the maximum size of the quartz crucible actually used in the single crystal furnace under test and the minimum size of the pulled silicon single crystal. For example, consider a maximum 18-inch quartz crucible and a minimum 4-inch silicon single crystal: The 18-inch quartz crucible has a diameter of approximately 450 mm. The corresponding concentric ring markings 104 on the measuring dial 10 mark the starting outer ring of the measurement. The 4-inch silicon single crystal has a diameter of approximately 100 mm, and the corresponding concentric ring markings 104 mark the ending inner ring of the measurement. The intersections of all the concentric ring markings 104 between the starting outer ring and the ending inner ring with the angle dividing lines 105 (divided into 15° intervals, totaling twenty-four angle intervals) are determined as measurement points. The diameter spacing between adjacent concentric ring markings 104 is set to 50 mm. There are twenty-four measurement points in one ring, measuring from 450 mm to 100 mm, with eight rings of 50 mm each. Including the center point, there are one hundred and ninety-three measurement points on one plane. This point distribution covers the entire radial range inside the crucible from the edge to the edge of the crystal growth solid-liquid interface, as well as all twenty-four angular directions around the crucible circumference, avoiding unnecessary measurements.

[0044] S50, obtains the maximum magnetic induction intensity value at each measurement point.

[0045] The operator holds a gaussmeter, turns it on, and zeros it. Then, the gaussmeter probe is aligned perpendicularly to the upper surface of the measuring dial 10, pointing towards the measurement point. The probe is aligned with the magnetic field lines 303 from the N pole 301 to the S pole 302. Because the transverse magnetic field 30 is symmetrical, the local direction of the magnetic field lines 303 at each measurement point is related to the spatial position of that point—the magnetic field strength is high on both sides parallel to the magnetic field lines (near the N and S poles), and low on both sides perpendicular to the magnetic field lines. A probe with a fixed angle cannot be precisely aligned with the local magnetic field lines at every measurement point. Therefore, the angle of the gaussmeter probe needs to be finely adjusted during measurement, while observing the change in magnetic flux density on the gaussmeter display. The maximum value during the change is taken as the magnetic flux density at that measurement point. By hand-holding and finely adjusting the probe angle and reading the maximum value, the probe's sensing surface can find the closest perpendicular orientation to the magnetic field lines 303 at the current position, thus obtaining the true maximum magnetic flux density value at that point.

[0046] S60, multi-plane measurement.

[0047] After completing the measurements at all points on the current horizontal plane, the measuring dial 10 is moved vertically downwards by a preset distance, such as 50 mm, using the crucible lifting mechanism. At this point, the upper surface of the measuring dial 10 corresponds to a certain depth below the surface of the molten silicon. Steps S40 and S50 are repeated on the new horizontal plane, measuring layer by layer downwards sequentially. Each descent can be 50 mm to 100 mm. The height of the molten silicon can be calculated based on the size of the quartz crucible and the weight of the molten silicon. For example, with 70 kg of molten silicon in an 18-inch quartz crucible, the height of the molten silicon is approximately 200 mm. With a descent of 50 mm, four descents are required, meaning a total of five horizontal planes need to be measured. This allows the acquisition of magnetic field strength distribution data for different planes within the entire height range from the molten silicon surface to the bottom of the crucible.

[0048] S70, Data Analysis. Summarize the magnetic induction intensity recorded at each measurement point in a data table, calculate the rate of change of magnetic induction intensity in the direction parallel to the magnetic field lines (along the direction from the N pole to the S pole) and in the direction perpendicular to the magnetic field lines, and evaluate the uniformity of the transverse magnetic field distribution inside the quartz crucible based on the rate of change.

[0049] Figure 7 This is a schematic diagram illustrating the magnetic flux density distribution along the direction of magnetic field lines and perpendicular to the inner wall of an 18-inch quartz crucible, according to an exemplary embodiment. (Refer to...) Figure 7 Taking the actual measurement data of this embodiment as an example for analysis: In the vertical direction, the maximum value of the central magnetic field strength appears on the central plane of the magnetic field. As the test position moves downward, the central magnetic field strength gradually weakens, and the further away from the central plane, the faster the magnetic field decays. The magnetic field strength at other measurement points also weakens accordingly. In the horizontal direction, on each test plane, the magnetic field strength is high near the crucible wall on both sides parallel to the magnetic field lines, and the lowest point is at the center; the opposite is true in the direction perpendicular to the magnetic field lines, with the highest point at the center and low magnetic field strength near the crucible wall on both sides—exhibiting an overall saddle-shaped distribution characteristic. This is because the transverse magnetic field is generated by two opposing magnetic poles. In the parallel direction, the closer to the magnetic pole, the higher the field strength; in the vertical direction, the farther away from the magnetic pole, the lower the field strength. Moreover, the magnetic field strength decays rapidly in the air. In the central plane of the magnetic field inside the single-crystal furnace quartz crucible, the change rate of magnetic induction intensity from the center to the N or S pole is approximately 2.9% per 100 mm in the direction parallel to the magnetic field lines, and the change rate of magnetic induction intensity from the center to the 90° direction is approximately -4.1% per 100 mm in the direction perpendicular to the magnetic field lines. As the test plane descends, the rate of change of magnetic induction intensity in both directions gradually increases, and the magnetic field attenuation intensifies. The uniformity of magnetic field intensity distribution at the solid-liquid interface during crystal growth with a diameter of 200 mm is approximately 1.8%, indicating that the magnetic field has a relatively uniform effect on crystal growth at this size, and the regional differences in convection conduction and solute transport at the solid-liquid interface are small.

[0050] In the above embodiment, the measuring dial achieves rapid coaxial positioning through the cooperation of the positioning steps and the crucible handle. The height and angle of the dial are adjusted using the existing crucible lifting and rotating mechanisms of the single crystal furnace, requiring no additional driving device. The concentric ring markings and angle dividing lines on the dial form a standardized grid of measurement points. Combined with the fine-tuning peak measurement method using a handheld gaussmeter probe, the true maximum magnetic induction intensity value is obtained at each measurement point. Through multi-plane measurement and data aggregation analysis, the uniformity distribution of the transverse magnetic field throughout the entire internal space of the quartz crucible can be quantitatively evaluated.

[0051] In summary, the measurement method provided in this embodiment uses a measuring dial as the core tool, simplifying the complex multi-axis motor-driven measurement into a combination of dial positioning and handheld single-point measurement. Compared to existing active measurement schemes that rely on multi-axis CNC motors, this method significantly reduces costs, simplifies the operation process, and overcomes the magnetic field directionality problem through probe fine-tuning peak measurement, resulting in more representative measurement results.

[0052] Example 3 The difference between this embodiment and Embodiment 2 is that a 45° central angle is used instead of a 15° central angle for measurement point selection. (Continue referring to...) Figures 4-5 To reduce the measurement load while ensuring measurement requirements, points were evenly divided at 45° intervals on the circumference of the measuring circle. Eight measurement points were selected: N 0°, N+45°, +90°, S+45°, S 0°, S-45°, -90°, and N-45°. This results in eight measurement points per circle. Measuring from 450 mm to 100 mm, with eight circles of 50 mm each, plus the center point, there are sixty-five measurement points on one plane. With five measurement planes, the total number of measurement points is three hundred and twenty-five.

[0053] Table 1 shows the measurement results of magnetic induction intensity at corresponding points inside an 18-inch quartz crucible.

[0054]

[0055]

[0056] Referring to Table 1, the actual measurement data of this embodiment is analyzed as an example: Taking the largest 18-inch quartz crucible and the smallest 4-inch silicon single crystal as examples, measurements are taken from 450 mm to 100 mm, with eight circles of 50 mm each. Including the center point, the number of measurement points on one plane is 65. The height of the molten silicon is calculated based on the size of the quartz crucible and the weight of the molten silicon. The height of 70 kg of molten silicon in an 18-inch quartz crucible is approximately 200 mm. Assuming the measuring dial descends by 50 mm each time, a total of five planes need to be measured, resulting in a total of 325 measurement points. This scheme reduces the workload of measurement while still covering all key angles and radial positions inside the crucible, making it suitable for scenarios requiring rapid acquisition of the general magnetic field distribution.

[0057] Other undescribed structures are described in Examples 1 and 2.

[0058] The above-disclosed content is only a preferred and feasible embodiment of the present invention, and is not intended to limit the scope of the patent application of the present invention. Therefore, all equivalent technical changes made based on the content of the present invention specification and drawings are included in the scope of the patent application of the present invention.

Claims

1. A measuring dial for the transverse magnetic field intensity distribution of a single-crystal furnace quartz crucible, characterized in that, include: The dial body is disc-shaped, and its bottom is provided with a positioning structure for coaxial positioning and limiting installation with the crucible support handle of the single crystal furnace; Magnetic pole markings are located on the dial body and are used to align with the N and S pole directions of the transverse magnetic field. Multiple concentric rings are arranged on the upper surface of the dial body with the center of the dial body as the center and different diameters as the radius. Each concentric ring corresponds to a standard diameter of the edge of a quartz crucible or the edge of the solid-liquid interface of crystal growth. An angular dividing line extends radially from the center of the dial body to the edge of the dial body, and divides the circumference of the dial body equally with a preset central angle. The intersection of the angular dividing line and the concentric ring mark forms a grid of magnetic field measurement points.

2. The measuring dial as described in claim 1, characterized in that, The positioning structure is a positioning step, the outer diameter and height of which are matched with the inner diameter and depth of the top step of the crucible handle, respectively, to achieve coaxial positioning and installation.

3. The measuring dial as described in claim 1, characterized in that, The angle dividing line divides the circumference of the dial body into 15° central angles, so that the circumference of the dial body is divided into twenty-four angle intervals.

4. The measuring dial as described in claim 1, characterized in that, The number of concentric ring markers is at least two, and includes at least a first concentric ring marker corresponding to the diameter of the quartz crucible and a second concentric ring marker corresponding to the edge diameter of the solid-liquid interface during crystal growth.

5. The measuring dial as described in claim 1, characterized in that, The magnetic pole markings are the letters N and S printed or engraved on the upper surface of the dial body, and the letters N and S are arranged opposite each other along the diameter direction of the dial body.

6. A method for measuring the transverse magnetic field intensity distribution of a single-crystal furnace quartz crucible, using the measuring dial according to any one of claims 1 to 5, characterized in that, include: The measuring dial is coaxially positioned and mounted on the crucible handle of the single crystal furnace using the positioning structure, so that the center of the measuring dial coincides with the rotation axis of the crucible handle. Adjust the vertical position of the measuring dial so that the upper surface of the measuring dial is flush with the central plane of the transverse magnetic field, and the central plane coincides with the position of the molten silicon surface during crystal growth; Rotate the crucible handle to drive the measuring dial to rotate around the rotation axis of the crucible handle, so that the magnetic pole markings are respectively aligned with the N pole direction and S pole direction of the transverse magnetic field; Determine the first concentric ring mark corresponding to the edge of the quartz crucible to be tested and the second concentric ring mark corresponding to the edge of the solid-liquid interface of the crystal growth. Determine the intersection of the first concentric ring mark, the second concentric ring mark, and the remaining concentric ring marks between them with the angle dividing line as the measurement point. At each of the measurement points, the maximum magnetic induction intensity value is obtained by taking the N-pole direction to the S-pole direction determined by the magnetic pole marking as the reference direction.

7. The measurement method as described in claim 6, characterized in that, The step of obtaining the maximum magnetic flux density value at each of the measurement points includes: measuring the magnetic flux density at each of the measurement points with a gaussmeter probe, and finely adjusting the angle of the gaussmeter probe to obtain the maximum magnetic flux density value at that measurement point.

8. The measurement method as described in claim 6, characterized in that, The measurement method further includes: after completing the measurement of all the measurement points on the current horizontal plane, moving the measuring dial vertically downward by a preset distance, and repeating the steps of determining the measurement points and obtaining the maximum magnetic induction intensity value on the new horizontal plane to obtain the magnetic field intensity distribution of different height planes inside the quartz crucible.

9. The measurement method as described in claim 8, characterized in that, The preset distance is 50 mm to 100 mm, and the number of times the measuring dial moves downward is determined according to the height of the molten silicon in the quartz crucible and the preset distance.

10. The measurement method as described in claim 6, characterized in that, The measurement method further includes: summarizing the magnetic induction intensity recorded at each measurement point in a data table, calculating the rate of change of magnetic induction intensity in the direction parallel to the magnetic field lines and in the direction perpendicular to the magnetic field lines, and evaluating the uniformity of the transverse magnetic field inside the quartz crucible based on the rate of change.

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