Length correction equipment and length correction method for seed crystal cable and ingot growth device

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By using encoder, load sensor and controller to measure and correct seed cable length during single crystal ingot growth, the problem of difficulty in controlling the ingot length is solved, and the stability and efficient production of ingot and wafer quality are achieved.

CN119824521APending Publication Date: 2025-04-15LG SILTRON

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Patent Information

Application Number: CN202411411175.1
Authority / Receiving Office: CN · China
Patent Type: Applications(China)
Current Assignee / Owner
Priority Date: 2023-10-12
Filing Date: 2024-10-10
Publication Date: 2025-04-15

AI Technical Summary

Technical Problem

During the growth process of single crystal ingots, it is difficult for the prior art to accurately control the length of the ingot, resulting in fluctuations in the mass of the ingot and wafers. The existing correction methods require trial and error processes, which increase the growth time and control difficulty.

Method used

A device and method for correcting seed cable length is provided, including an encoder, a load sensor and a controller, to accurately control the ingot length by measuring seed cable length and ingot weight, calculate correction values and correct seed cable length.

Benefits of technology

Accurate measurement and control of seed cable and ingot lengths is achieved, reducing ingot and wafer mass fluctuations, simplifying the growth process and improving production efficiency.

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Abstract

A length correction apparatus for a seed cable may include: an encoder configured to measure a length of the seed cable; a load sensor configured to measure a weight of an ingot grown using the seed cable; and a controller. The controller is configured to: obtain a correction value by multiplying the measured length of the seed cable by the measured weight of the ingot; and correcting the length of the seed crystal cable based on the obtained correction value.

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Description

Technical Field

[0001] The present embodiment relates to a seed cable length correction device, a seed cable length correction method and an ingot growing apparatus. Background Art

[0002] Single crystal ingots are grown and processed to form wafers. Since the quality of the wafer is directly affected by the quality of the ingot, advanced process control techniques are required from the time the ingot is grown.

[0003] The Czochralski (Cz) method is used to grow single crystal ingots. The ratio of the crystal growth rate V to the temperature gradient G at the solid-liquid interface, V / G, is widely considered to be an important factor that directly affects the quality of the ingot. During the entire crystal growth process, it is very important to control V / G to reach the set target trajectory value.

[0004] The growth rate V is estimated based on the length of the growing ingot. In order to control the precise growth rate V, it is necessary to precisely control the ingot length. For example, the length of a seed cable is measured, and the length of the ingot is obtained based on the measured length of the seed cable.

[0005] At the same time, the weight (or load) of the ingot connected to the seed cable also increases with the increase of its length. As the weight of the ingot increases, the length of the seed cable deforms. Therefore, the length of the seed cable increases the strain amount as the weight of the ingot increases. At this time, the strain amount of the seed cable length varies depending on the measured length of the seed cable and the weight of the ingot.

[0006] like Figure 1A and Figure 1B As shown, as the driving motor 2 reduces the lengths L11 and L12 of the seed cable 3, the lengths L21 and L22 of the ingot IG increase. That is, as the driving motor 2 makes the second length L12 of the seed cable 3 shorter than the first length L11 of the seed cable 3, the second length L22 of the ingot IG is longer than the first length L21 of the ingot IG.

[0007] However, as the ingot IG connected to the seed cable 3 increases from the first length L21 to the second length L22, the weight of the ingot IG also increases. Therefore, as the actual seed cable 3 increases from the second length L12 to the third length L13 due to the weight of the ingot IG, the ingot IG decreases from the second length L22 to the third length L23. That is, the length L13 of the actual seed cable 3 increases by the strain amount δ, while the length L23 of the ingot IG decreases by the strain amount δ.

[0008] Finally, there is a problem that due to the deformations L12 and L13 of the length of the seed cable 3 caused by the weight of the ingot IG, errors occur in the measurement of the lengths L22 and L23 of the ingot IG and the drawing speed of the ingot IG.

[0009] Since these errors in the measurement of the pulling speed of the ingot IG and the length L22, L23 of the ingot IG are important factors in the quality fluctuation of the ingot and the wafer, it is urgently required to develop a new technology for correcting the measurement errors.

[0010] Meanwhile, in the prior art, a method is used in which the actual length is compared with the target length just before the ingot is produced, and in the event of a large measurement error, the factor is corrected. However, this method requires a trial and error process to find the factor value within the allowable error range, which makes the ingot growth process longer and makes it difficult to control the precise length of the ingot. Summary of the invention

[0011] Embodiments are directed to solving the above-referenced problems and other problems.

[0012] Another object of an embodiment is to provide a length correction device for a seed cable, a length correction method for a seed cable, and an ingot growing apparatus capable of controlling the precise length of an ingot.

[0013] Technical problems of the embodiment are not limited to those described in this item, and include those that can be understood through the description of the present invention.

[0014] According to a first aspect of an embodiment, in order to achieve the above-mentioned purpose or other purposes, a length correction device for a seed cable is provided, comprising: an encoder configured to measure the length of the seed cable; a load sensor configured to measure the weight of an ingot grown using the seed cable; and a controller, wherein the controller is configured to correct the length of the seed cable based on the measured length of the seed cable and the measured weight of the ingot.

[0015] The controller may obtain a correction value based on the measured length of the seed cable and the measured weight of the ingot; and correct the length of the seed cable based on the obtained correction value.

[0016] The correction value may be a strain amount of the length of the seed cable, which varies according to the length of the seed cable and the weight of the ingot.

[0017] The controller may obtain a corrected length of the seed cable by adding the obtained correction value to the measured length of the seed cable.

[0018] The controller may obtain a corrected length of the ingot by subtracting the obtained correction value from the length of the ingot when measuring the seed cable.

[0019] The correction value can be calculated by the following mathematical formula 1.

[0020] [Mathematical formula 1]

[0021] δ=PL / EA

[0022] δ is the correction value, P is the weight of the ingot, L is the length of the seed cable, E is the elastic modulus of the seed cable, and A is the cross-sectional area of the seed cable.

[0023] According to a second aspect of the embodiment, in order to achieve the above-mentioned purpose or other purposes, a method for correcting the length of a seed cable is provided, comprising: measuring the length of the seed cable; measuring the weight of an ingot grown using the seed cable; and correcting the length of the seed cable based on the measured length of the seed cable and the measured weight of the ingot.

[0024] Correcting the length of the seed cable may include: obtaining a correction value based on a measured length of the seed cable and a measured weight of the ingot; and correcting the length of the seed cable based on the obtained correction value.

[0025] The correction value may be a dependent amount of the length of the seed cable that varies according to the length of the seed cable and the weight of the ingot.

[0026] Correcting the length of the seed cable may include obtaining a corrected length of the seed cable by adding the obtained correction value to the measured length of the seed cable.

[0027] Correcting the length of the seed cable may include obtaining a corrected length of the ingot by subtracting the obtained correction value from the length of the ingot when measuring the seed cable.

[0028] According to a third aspect of the embodiment, in order to achieve the above-mentioned purpose or other purposes, there is provided an ingot growing device, comprising: a crucible; a pulling device, the pulling device comprising a seed cable, the seed cable being configured to pull up an ingot grown from a molten liquid contained in the crucible; an encoder installed in the pulling device and configured to measure the length of the seed cable; a load sensor installed in the pulling device and configured to measure the weight of the ingot; and a controller, wherein the controller is configured to correct the length of the seed cable based on the measured length of the seed cable and the measured weight of the ingot.

[0029] The controller may obtain a correction value based on the measured length of the seed cable and the measured weight of the ingot; and correct the length of the seed cable based on the obtained correction value.

[0030] The correction value may be a strain amount of the length of the seed cable, which varies according to the length of the seed cable and the weight of the ingot.

[0031] As follows, effects of the length correction apparatus for a seed cable, the length correction method for a seed cable, and the ingot growing device according to the embodiment are described.

[0032] According to at least one embodiment, by correcting the length of the seed cable based on the length of the seed cable measured by the encoder and the weight of the ingot measured by the load sensor, the precise length of the seed cable or the ingot can be obtained. Therefore, precise length control of the ingot is possible, so that high-quality ingots or wafers can be manufactured.

[0033] According to the following detailed description, the additional applicable scope of the embodiment will become obvious. However, since those skilled in the art can clearly understand various changes and modifications within the concept and scope of the embodiment, the specific description and specific embodiments (such as preferred embodiments) should be understood to be given by way of example only. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1A and Figure 1B : is a graph showing the error in measuring the length of the seed cable.

[0035] Figure 2 is a diagram showing an ingot growing apparatus according to an embodiment.

[0036] Figure 3 is a flow chart illustrating a method for correcting the length of a seed cable according to an embodiment.

[0037] Figure 4 It is a detailed description Figure 3 Flowchart of S230.

[0038] FIG. 5 shows the correction value that varies according to the increase in the length of the seed cable.

[0039] Figure 6 It is a graph showing the strain amount according to the weight of the ingot.

[0040] The size, shape, dimensions, etc. of the elements shown in the drawings may be different from the actual size, shape, dimensions, etc. In addition, even if the same element is shown in different sizes, shapes, dimensions, etc. between the drawings, this is only an example on the drawings, and the same element has the same size, shape, dimensions, etc. between the drawings. DETAILED DESCRIPTION

[0041] Hereinafter, the embodiments disclosed in this specification will be described in detail with reference to the accompanying drawings, but regardless of the figure numerals, the same or similar elements are given the same figure numerals, and their redundant descriptions will be omitted. In view of the convenience of writing the specification, the suffixes "module" and "unit" of the elements used in the following description are given or used interchangeably, and "module" and "unit" themselves do not have different meanings or functions from each other. In addition, the accompanying drawings are for the convenience of understanding the embodiments disclosed in this specification, and the technical ideas disclosed in this specification are not limited by the accompanying drawings. In addition, when an element such as a layer, a region or a substrate is referred to as "on another element", this means that the element can be directly on another element or there are other intermediate elements between them.

[0042] In the following examples, the strain amount and the correction value may be used interchangeably. In the following examples, the strain amount may refer to the strain amount of the length of the seed cable.

[0043] Figure 2 is a diagram showing an ingot growing apparatus according to an embodiment.

[0044] refer to Figure 2 , the ingot growing apparatus 100 according to the embodiment may include a crucible 110 , a pulling device 120 , and a length correction device 130 of a seed cable 123 .

[0045] The molten liquid 111 may be contained in the crucible 110. The molten liquid 111 may be silicon (Si) or silicon carbide (SiC), but is not limited thereto.

[0046] The pulling device 120 may include a drive motor 121, a seed cable 123, and the like. The seed cable 123 may be connected to the drive motor 121. The length L of the seed cable 123 may be changed by the rotation of the drive motor 121. That is, the seed cable 123 may be raised and lowered according to the rotation of the drive motor 121. For example, when the drive motor 121 rotates forward, the seed cable 123 may be lowered from the drive motor 121. For example, when the drive motor 121 rotates backward, the seed cable 123 may be raised toward the drive motor 121. The seed cable 123 may be lowered and contacted with the molten liquid 111 contained in the crucible 110. The seed crystal (not shown) mounted on the lower side of the seed cable 123 contacts the molten liquid 111, and a single crystal ingot may be grown by the seed crystal. Then, the length of the ingot may be increased by raising the seed cable 123.

[0047] The length L of the seed cable 123 and the length of the ingot may be inversely proportional. That is, when the seed cable 123 is raised for the growth of the ingot, the length L of the seed cable 123 may decrease, while the length of the ingot may increase. The length of the ingot according to the length L of the seed cable 123 may be made into a lookup table and stored in a memory (not shown). When the length L of the seed cable 123 is measured by the encoder 131, the lookup table may be used to obtain the length of the ingot corresponding to the specified length L of the seed cable 123.

[0048] Meanwhile, the length correction device 130 of the seed cable 123 may include an encoder 131 , a load sensor 133 , and a controller 135 .

[0049] The encoder 131 may measure the length L of the seed cable 123. In an embodiment, the encoder 131 may be an incremental encoder, but is not limited thereto. The encoder 131 may be connected to one side of the drive motor 121 and may output a signal corresponding to the rotation of the drive motor 121. Since the encoder 131 is well known, a detailed description thereof will be omitted.

[0050] The load cell 133 may measure the weight of the ingot. As described above, the ingot may be grown using seeds mounted on the underside of the seed cable 123. As the seed cable 123 rises, the length of the growing ingot increases.

[0051] The load sensor 133 may be installed at one side of the seed cable 123, but is not limited thereto. The load sensor 133 may measure the weight of the ingot connected to the seed cable 123. The load sensor 133 may be a gyroscopic load sensor 133 or a strain gauge load sensor 133, but is not limited thereto. Since the load sensor 133 is well known, a detailed description thereof will be omitted.

[0052] Meanwhile, the controller 135 may correct the length L of the seed cable 123 based on the length L of the seed cable 123 and the weight of the ingot.

[0053] As described above, as the seed cable 123 is raised, the length of the ingot increases, and thus the weight of the ingot may increase. Since the seed cable 123 has a predetermined elastic modulus, the strain of the length L of the seed cable 123 changes as the weight of the ingot increases. The strain of the length L may also be referred to as elongation.

[0054] like Figure 5A As shown, when the seed cable 123 has a first length L31, the ingot IG connected to the seed cable 123 may have a first length L41. Figure 5B As shown, when the seed cable 123 is raised to have a second length L32, the ingot IG may have a second length L42. Figure 5CAs shown, when the seed cable 123 is further raised to have a third length L33, the ingot IG may have a third length L43. Here, the second length L32 of the seed cable 123 may be less than the first length L31, and the third length L33 may be less than the second length L32. In the ingot IG, the second length L42 may be greater than the first length L41, and the third length L43 may be greater than the second length L42.

[0055] In this case, in the case where the ingot IG has a first length L41, a first strain amount δ1 is generated in the seed cable 123, so that the lower side of the seed cable 123 can be located at a position lower than the first length L31 by the first strain amount δ1. Therefore, compared with the first length L41, the length of the ingot IG can be reduced by the first strain amount δ1. When the ingot IG grows to a second length L42 greater than the first length L41, a second strain amount δ2 greater than the first strain amount δ1 is generated in the seed cable 123, so that the lower side of the seed cable 123 can be located at a position lower than the second length L32 by the second strain amount δ2. Therefore, compared with the second length L42, the length of the ingot IG can be reduced by the second strain amount δ2. When the ingot IG grows to a third length L43 greater than the second length L42, a third strain amount δ3 greater than the second strain amount δ2 is generated in the seed cable 123, so that the lower side of the seed cable 123 can be located at a position lower than the third length L33 by the third strain amount. Therefore, the length of the ingot IG can be reduced by the third strain amount δ3 compared to the third length L43.

[0056] Therefore, as the length of the ingot IG increases, different strain amounts δ1, δ2, δ3 are generated in the seed cable 123, so that the lengths L31, L32, L33 of the seed cable 123 increase the corresponding strain amounts δ1, δ2, δ3, and therefore, the lengths L41, L42, L43 of the ingot IG can reduce the corresponding strain amounts δ1, δ2, δ3. Therefore, errors are generated in the measurement of the lengths L31, L32, and L33 of the seed cable 123, which may respectively result in multiple errors in multiple measurements of the lengths of the ingot IG.

[0057] Therefore, there is an urgent need to develop a technology capable of measuring the precise length of the seed cable 123 or the ingot IG by considering the corresponding strain amounts δ1, δ2, and δ3.

[0058] According to an embodiment, the controller 135 can obtain the precise length of the seed cable 123 or the ingot IG by correcting the length of the seed cable 123 based on the length of the seed cable 123 measured by the encoder 131 and the weight of the ingot IG measured by the load sensor 133. Therefore, the precise length of the ingot IG can be controlled so that a high-quality ingot IG or wafer can be manufactured.

[0059] In an embodiment, the controller 135 may obtain a correction value based on the length of the seed cable 123 and the weight of the ingot IG. Here, the correction value may be the aforementioned strain amount. That is, the correction value may be the strain amount of the length of the seed cable 123 that varies according to the length of the seed cable 123 and the weight of the ingot IG. The controller 135 may correct the length of the seed cable 123 based on the correction value.

[0060] The correction value can be expressed by the following mathematical formula 1.

[0061] [Mathematical formula 1]

[0062] δ=PL / EA

[0063] δ is a correction value, P is the weight of the ingot IG, L is the length of the seed cable 123 , E is the elastic modulus of the seed cable 123 , and A is the cross-sectional area of the seed cable 123 .

[0064] Here, the elastic coefficient E of the seed cable 123 and the cross-sectional area A of the seed cable 123 may be fixed values, ie, constants. Therefore, as shown in Mathematical Formula 1, the correction value δ may be determined by multiplying the weight of the ingot IG by the length of the seed cable 123 .

[0065] like Figure 6 As shown, it can be seen that different correction values δ11, δ12, δ13 and δ14 are obtained according to the weight of the ingot. This may be due to the different increase rates of the weight of the ingot and the length of the seed cable 123 in Mathematical Formula 1. For example, the correction values δ11, δ12 increase until the weight of the ingot reaches 200 kg, and then the correction values δ13, δ14 decrease until the weight of the ingot exceeds 200 kg and reaches the target value of 400 kg.

[0066] At the same time, the controller 135 may add the correction value to the length of the seed cable 123. When measuring the seed cable 123, the controller 135 may subtract the correction value from the length of the ingot.

[0067] For example, Figure 5B As shown, when the seed cable 123 has a second length L32, the weight of the ingot IG is measured, and the second length L32 of the seed cable 123 and the measured weight of the ingot IG are substituted into Mathematical Formula 1 to obtain a second correction value δ2. As described above, the second correction value δ2 may be a strain or elongation of the length of the seed cable 123.

[0068] The controller can obtain the corrected length of the seed cable 123 by adding the correction value to the length of the seed cable. Figure 5BAs shown, the second strain amount δ2, i.e., the second correction value, can be added to the second length L32 of the seed cable 123, so as to obtain the corrected length of the seed cable 123. The corrected length of the seed cable 123 can be the sum of the second length L32 of the seed cable 123 measured by the encoder 131 and the second strain amount δ2. The second length L32 of the seed cable 123 can be increased by the second strain amount δ2 to become the corrected length of the seed cable 123.

[0069] As described above, when the second length L32 of the seed cable 123 is measured, a lookup table can be used to obtain the length of the ingot IG corresponding to the second length L32 of the seed cable 123. As the length of the seed cable 123 increases, the length of the ingot IG can be reduced. Therefore, the controller 135 can obtain the corrected length of the ingot IG by subtracting the second strain amount δ2 from the second length L42 of the ingot IG. The corrected length of the ingot IG can be the sum of the length of the ingot IG and the second strain amount δ2. As the length of the seed cable 123 increases, the length of the ingot IG can be reduced. That is, the length of the seed cable 123 can be increased by the second strain amount δ2, while the length of the ingot IG can be reduced by the second strain amount δ2.

[0070] Figure 3 is a flow chart illustrating a method for correcting the length of a seed cable according to an embodiment. Figure 4 It is a detailed description Figure 3 Flowchart of S230.

[0071] refer to Figure 2 and Figure 3 , the encoder 131 may measure the length of the seed cable 123 ( S210 ). The controller 135 may control the encoder 131 to measure the length of the seed cable 123 .

[0072] The load sensor 133 may measure the weight of the ingot ( S220 ). When the seed cable 123 rises, the ingot may grow via the seed of the seed cable 123 , so that the weight of the ingot may increase. The controller 135 may measure the weight of the ingot by controlling the load sensor 133 .

[0073] The controller 135 may correct the length of the seed cable 123 based on the length of the seed cable 123 and the weight of the ingot ( S230 ).

[0074] like Figure 4 As shown, the controller 135 may obtain a correction value based on the length of the seed cable 123 and the weight of the ingot (S231).

[0075] The controller 135 may correct the length of the seed cable 123 based on the correction value. For example, the controller 135 may add the correction value to the length of the seed cable 123 (S232). Therefore, the corrected length of the seed cable 123 may be obtained. Conversely, when measuring the length of the seed cable 123, the controller 135 may obtain the length of the ingot corresponding to the length of the seed cable 123 by using a lookup table. Then, the controller 135 may obtain the corrected length of the ingot by subtracting the correction value from the length of the ingot.

[0076] The above detailed description should not be construed as limiting in all aspects, but should be regarded as illustrative. The scope of the embodiments should be determined by reasonable interpretation of the appended claims, and all changes within the equivalent scope of the embodiments are included in the scope of the embodiments.

Claims

1. A length correction device for a seed cable, comprising: an encoder configured to measure a length of the seed cable; a load sensor configured to measure the weight of an ingot grown using the seed cable; as well as Controller, Wherein, the controller is configured as: obtaining a correction value by multiplying the measured length of the seed cable by the measured weight of the ingot; and The length of the seed cable is corrected based on the obtained correction value.

2. The length correction device according to claim 1, wherein: The correction value is a strain amount of the length of the seed cable, and the strain amount varies according to the length of the seed cable and the weight of the ingot.

3. The length correction device according to claim 1, wherein: The controller is configured to obtain a corrected length of the seed cable by adding the obtained correction value to the measured length of the seed cable.

4. The length correction device according to claim 1, wherein: The controller is configured to obtain a corrected length of the ingot by subtracting the obtained correction value from the length of the ingot when measuring the seed cable.

5. The length correction device according to claim 1, wherein: The correction value is calculated by the following mathematical formula 1: [Mathematical formula 1] δ=PL / EA δ is the correction value, P is the weight of the ingot, L is the length of the seed cable, E is the elastic modulus of the seed cable, and A is the cross-sectional area of the seed cable.

6. A method for length correction of a seed cable, comprising: measuring the length of the seed cable; measuring the weight of an ingot grown using the seed cable; obtaining a correction value by multiplying the measured length of the seed cable by the measured weight of the ingot; as well as The length of the seed cable is corrected based on the obtained correction value.

7. The length correction method according to claim 6, wherein: The correction value is a strain amount of the length of the seed cable, and the strain amount varies according to the length of the seed cable and the weight of the ingot.

8. The length correction method according to claim 6, wherein: The step of correcting the length of the seed cable comprises: A corrected length of the seed cable is obtained by adding the obtained correction value to the measured length of the seed cable.

9. The length correction method according to claim 6, wherein: The step of correcting the length of the seed cable comprises: The corrected length of the ingot is obtained by subtracting the obtained correction value from the length of the ingot when measuring the seed cable.

10. An ingot growing device, comprising: Crucible; a pulling apparatus including a seed cable configured to pull up an ingot grown from a molten liquid contained in the crucible; an encoder mounted in the pulling apparatus and configured to measure a length of the seed cable; a load sensor installed in the pulling apparatus and configured to measure the weight of the ingot; as well as Controller, Wherein, the controller is configured as: obtaining a correction value by multiplying the measured length of the seed cable by the measured weight of the ingot; and The length of the seed cable is corrected based on the obtained correction value.

11. The ingot growing device according to claim 10, wherein: The correction value is a strain amount of the length of the seed cable, and the strain amount varies according to the length of the seed cable and the weight of the ingot.