Temperature calibration method, measurement method and measurement device for crystal growth furnace

Abstract

The application provides a temperature calibration method, a measuring method and a measuring device of a crystal growth furnace. The calibration method comprises: obtaining a volume change rate of a crystal at at least two temperatures in a target temperature range; wherein the target temperature range contains a melting point of the crystal; determining temperature values of the at least two temperatures according to the obtained volume change rate and a pre-stored empirical value curve of the volume change rate of the crystal in the target temperature range; obtaining image gray scales of a target region in the furnace at the at least two temperatures; and determining a corresponding relationship between the image gray scales of the target region and the temperatures in the target temperature range according to the obtained image gray scales and the temperature values of the at least two temperatures. The calibration method can facilitate subsequent temperature measurement of the crystal growth furnace, avoid purchase of expensive equipment, simplify equipment operation, and greatly reduce costs.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of crystal growth, in particular to a temperature calibration method, a measurement method and a measurement device of a crystal growth furnace. BACKGROUND

[0002] The growth of single crystals such as silicon, silicon carbide, lithium niobate, lithium tantalate, etc. is in a closed crystal growth furnace above 1000 degrees. Different stages of the growth process need to control different temperatures. Currently, the power of the heating furnace is controlled by artificial experience, and the color, crystal shape, etc. in the furnace are observed through the observation hole by the human eye for judgment.

[0003] In order to solve the problem of automation of crystal growth, the temperature in the furnace needs to be precisely measured, so as to automatically control the growth process. To solve this problem, the emission spectrum, multi-spectrum, hyperspectrum, etc. are usually used to measure the temperature in high temperature field. For example, patent CN116124319A measures the flame temperature by connecting the optical fiber spectrometer of the high temperature endoscope; patent CN112834051B measures the flame temperature by multi-spectrum camera. However, the instruments required by the above measurement methods are expensive and complex to operate, and it is difficult to apply them on a large scale. SUMMARY

[0004] Therefore, the present application aims to provide an improved temperature calibration method, measurement method and measurement device of a crystal growth furnace to solve at least one of the above problems.

[0005] In a first aspect, the present application provides a temperature calibration method of a crystal growth furnace, comprising:

[0006] obtaining the volume change rate of the crystal at least two temperatures in a target temperature range; wherein the target temperature range contains the melting point of the crystal;

[0007] determining the temperature values of the at least two temperatures according to the obtained volume change rate and the pre-stored volume change rate empirical value curve of the crystal in the target temperature range;

[0008] obtaining the image gray scale of the target region in the furnace at the at least two temperatures;

[0009] determining the corresponding relationship between the image gray scale of the target region and the temperature in the target temperature range according to the obtained image gray scale and the temperature values of the at least two temperatures.

[0010] The calibration method measures the volume change rate of the crystal at at least two temperatures, and then combines the pre-stored volume change rate and temperature experience value curve to determine the temperature values of the at least two temperatures. Then, the temperature of the crystal growth furnace is calibrated by using the temperature evaluation quantity of the target region in the furnace at the at least two temperatures. The method facilitates the subsequent temperature measurement of the crystal growth furnace, avoids the purchase of expensive equipment, simplifies the operation of the equipment, and greatly reduces the cost.

[0011] In one of the embodiments, the sidewall of the crystal growth furnace is provided with an observation window for observing the crystal in the furnace. The method for obtaining the volume change rate of the crystal at at least two temperatures in the target temperature range comprises: obtaining a first image and a second image of the crystal at a preset time interval at a temperature in the target temperature range; determining the lateral change rate of the crystal according to the first image, the second image and the preset time; obtaining the longitudinal change rate of the crystal; determining the volume change rate of the crystal at the temperature according to the longitudinal change rate and the lateral change rate; and repeating the above steps to obtain the volume change rate of the crystal at at least another temperature in the target temperature range.

[0012] In one of the embodiments, the volume change rate experience value curve is obtained by pre-measuring the volume change rate of the crystal at different temperatures combined with the corresponding temperature.

[0013] In one of the embodiments, the target temperature range is a temperature range of the melting point temperature ± 5℃.

[0014] In one of the embodiments, the volume change rate comprises at least one of the growth rate of the crystal and the melting rate of the crystal.

[0015] In one of the embodiments, the method for obtaining the image gray scale of the target region in the furnace at the at least two temperatures comprises: determining the image gray scale of the target region in the furnace at the temperature according to at least one image at the temperature; and determining the image gray scale of the target region in the furnace at at least another temperature according to at least one image at the at least another temperature.

[0016] Correspondingly, the method for determining the corresponding relationship between the temperature evaluation quantity of the target region and the temperature of each temperature in the target temperature range according to the obtained temperature evaluation quantity and the temperature values of the at least two temperatures comprises: determining the gray scale change curve of the image gray scale of the target region in the target temperature range according to the obtained image gray scale and the temperature values corresponding to each of the image gray scales.

[0017] Secondly, this application provides a temperature measurement method for a crystal growth furnace, comprising: acquiring a target image containing a target region inside the furnace; determining the image grayscale of the target region inside the furnace based on the target image; and determining the furnace temperature based on the image grayscale and the grayscale change curve obtained by the method described in the preceding embodiments.

[0018] The above measurement method, by measuring the image grayscale of the target area inside the furnace and combining it with the calibrated grayscale change curve of the target area within the target temperature range, can quickly infer the furnace temperature. This helps avoid the purchase of expensive equipment, simplifies equipment operation, and significantly reduces costs.

[0019] Thirdly, this application provides a measuring device for a crystal growth furnace, wherein the side wall of the crystal growth furnace is provided with an observation window for convenient acquisition of images of the crystal inside the furnace, comprising: a first acquisition module configured to acquire the volume change rate of the crystal at at least two temperatures within a target temperature range, wherein the target temperature range includes the melting point of the crystal; a first determination module connected to the first acquisition module configured to determine the temperature values ​​of the at least two temperatures based on the acquired volume change rate and a pre-stored empirical value curve of the volume change rate of the crystal within the target temperature range; a second acquisition module connected to the first determination module configured to acquire the image grayscale of a target area inside the furnace at the at least two temperatures; and a second determination module connected to the second acquisition module configured to determine the correspondence between the image grayscale of the target area and each temperature within the target temperature range based on the acquired image grayscale and the temperature values ​​of the at least two temperatures.

[0020] The aforementioned measuring device, before measuring the furnace temperature, can first determine the temperature values ​​of the at least two temperatures by measuring the volume change rate of the crystal at at least two temperatures, and then by combining this with empirical curves of volume change rate versus temperature obtained through human observation. Next, the temperature evaluation values ​​of the target area within the furnace at these at least two temperatures are used to calibrate the temperature inside the crystal growth furnace. This not only facilitates subsequent temperature measurement of the crystal growth furnace but also avoids the purchase of expensive equipment, simplifies equipment operation, and significantly reduces costs.

[0021] In one embodiment, the system further includes: a third acquisition module configured to acquire the image grayscale of the target region; and a third determination module connected to the third acquisition module and the second determination module, configured to determine the temperature inside the crystal growth furnace based on the image grayscale and the correspondence.

[0022] Fourthly, this application provides a computer-readable storage medium for storing a computer program that causes a computer to perform the steps described in the preceding embodiments. Attached Figure Description

[0023] To more clearly illustrate the technical solutions in the embodiments of this specification or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in this specification. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0024] Figure 1 This is a flowchart illustrating the steps of a calibration method according to an embodiment of this application;

[0025] Figure 2 This is a schematic diagram of furnace temperature calibration / measurement according to an embodiment of this application;

[0026] Figure 3 This is a first image of a crystal according to an embodiment of this application at a first temperature;

[0027] Figure 4 This is a second image of a crystal according to an embodiment of this application at a second temperature;

[0028] Figure 5 The growth rate curves of a crystal at different temperatures according to an embodiment of this application are shown.

[0029] Figure 6 The melting rate curves of a crystal according to an embodiment of this application at different temperatures are shown.

[0030] Figure 7 A schematic diagram of the target area inside the furnace according to an embodiment of this application is shown;

[0031] Figure 8 The grayscale variation curve of one embodiment of this application is shown;

[0032] Figure 9 This is a schematic diagram of the composition of a measuring device according to an embodiment of this application. Detailed Implementation

[0033] To make the above-mentioned objects, features, and advantages of the present invention more apparent and understandable, specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings. Many specific details are set forth in the following description to provide a thorough understanding of the present invention. However, the present invention can be practiced in many other ways different from those described herein, and those skilled in the art can make similar modifications without departing from the spirit of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0034] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0035] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this invention, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0036] It should be noted that when an element is referred to as being "fixed to" or "set on" another element, it can be directly on the other element or there may be an intervening element. When an element is considered to be "connected to" another element, it can be directly connected to the other element or there may be an intervening element. The terms "vertical," "horizontal," "upper," "lower," "left," "right," and similar expressions used herein are for illustrative purposes only and do not represent the only possible implementation.

[0037] This application provides a simple and accurate method for calibrating the temperature of a crystal growth furnace. The method involves measuring the volume change rate of the crystal at at least two temperatures, then combining this with pre-stored empirical curves of crystal volume change rate versus temperature to determine the temperature values ​​for these at least two temperatures. Finally, the temperature evaluation values ​​of the target area within the furnace at these at least two temperatures are used to calibrate the temperature within the crystal growth furnace. This method facilitates subsequent temperature measurements of the crystal growth furnace, avoids the purchase of expensive equipment, simplifies equipment operation, and significantly reduces costs.

[0038] like Figure 1 As shown in the figure, this application provides a method for temperature calibration of a crystal growth furnace, including the following steps:

[0039] S100. Obtain the rate of volume change of the crystal at at least two temperatures within a target temperature range; wherein the target temperature range includes the melting point of the crystal.

[0040] For example, when the temperature in the target temperature range is less than the melting point, the rate of volume change of the crystal can be the growth rate of the crystal; when the temperature in the target temperature range is greater than or equal to the melting point, the rate of volume change of the crystal can be the melting rate of the crystal.

[0041] Optionally, the heating power can be controlled to raise the furnace temperature below the melting point, and the lifting rod can be controlled to lower the seed crystal below the liquid surface. Then, the crystal volume increase rate (i.e., crystal growth rate) can be obtained based on the lateral expansion rate of the crystal and the lifting speed of the lifting rod.

[0042] Optionally, the furnace temperature can be raised to a level greater than or equal to the melting point by controlling the heating power. Then, the volume reduction rate of the crystal (i.e., the melting rate of the crystal) can be obtained based on the lateral shrinkage rate of the crystal and the descent rate of the lifting rod.

[0043] For example, "at least two temperatures" means two or more temperatures, such as two, three, four, five, six, etc. The more temperatures there are, the more accurate the subsequent calibration results will be.

[0044] S200. Based on the obtained volume change rate and the empirical value curve of the volume change rate of the crystal in the target temperature range, determine the temperature values ​​of at least two temperatures.

[0045] For example, the empirical value curve of the crystal volume change rate reflects the relationship between the crystal volume change rate and temperature. Therefore, based on the actual measured crystal volume change rate, the furnace temperature corresponding to the measured volume change rate can be inferred by combining the pre-stored empirical value curve.

[0046] For example, an empirical curve of the volume change rate can be obtained by pre-measuring the volume change rate of the crystal at different temperatures and plotting it in conjunction with the corresponding temperature.

[0047] Optionally, a crystal growth image can be acquired at predetermined intervals (e.g., 1 second) at a known first set temperature. By analyzing the aperture changes in the image, the contour changes at the contact point between the seed crystal and the liquid surface can be calculated, thereby obtaining the lateral expansion rate of the crystal. Combined with the pulling speed, the growth rate of the crystal at the first set temperature can be obtained. Then, the above steps can be repeated at a known second set temperature to obtain the volume change rate at the second set temperature. By repeating this process multiple times, the desired empirical value curve of the volume change rate can be obtained based on multiple different set temperatures and corresponding crystal volume change rates.

[0048] S300: Obtain temperature evaluation values ​​for the target area inside the furnace at at least two temperatures.

[0049] For example, the temperature evaluation quantity can be a quantity positively correlated with the furnace temperature, such as the image grayscale of a target area within the furnace. Optionally, the target area can be the region at or near the crystal growth interface. It should be noted that the target area should avoid reflections, dirt, etc., to prevent image errors from affecting the measurement of the temperature evaluation quantity.

[0050] S400. Based on the obtained temperature evaluation quantity and the temperature values ​​of at least two temperatures, determine the correspondence between the temperature evaluation quantity of the target area and each temperature within the target temperature range.

[0051] For example, when the temperature evaluation quantity is the image grayscale of the target area inside the furnace, the grayscale change curve of the image grayscale of the target area within the target temperature range can be determined based on the obtained image grayscale and the temperature value corresponding to each image grayscale.

[0052] In some embodiments of this application, such as Figure 2 As shown, the side wall of the crystal growth furnace has an observation window for viewing the crystal inside the furnace. A camera can image the lifting rod, seed crystal, and liquid surface area through this observation window. Optionally, the camera can be a research-grade area array camera (CCD or CMOS) with high dynamic range, low noise, and a 16 / 18-bit high-precision ADC. Optionally, the camera has a very small fixed aperture, so that the light intensity entering the camera is constantly attenuated, thereby ensuring that the radiation intensity in the furnace near the crystal melting point is within the camera's dynamic range. Therefore, step S100 may include:

[0053] S110. Acquire a first image and a second image of the crystal at a temperature within a target temperature range, separated by a preset time interval.

[0054] S120. Determine the lateral change rate of the crystal based on the first image, the second image, and the preset time.

[0055] S130, Obtain the longitudinal change rate of the crystal;

[0056] S140. Determine the volume change rate of the crystal at this temperature based on the longitudinal and transverse change rates.

[0057] S150. Repeat the above steps to obtain the rate of volume change of the crystal at at least another temperature within the target temperature range.

[0058] Optionally, the furnace temperature can be raised below the melting point first, and the lifting rod can be controlled to lower the seed crystal below the liquid surface. Then, a camera can be used to capture the first image of the crystal at the first moment at the first temperature, such as... Figure 3 As shown; then, after a preset time interval, a second image of the crystal at a second moment at the first temperature is acquired by a camera, as shown. Figure 4 As shown. You can see that,Figure 4 The interface between the seed crystal and the liquid surface compared to Figure 3 The interface between the seed crystal and the liquid surface is significantly enlarged, indicating crystal growth. By combining the first and second images with a method of measuring the crystal growth profile through an aperture, the lateral expansion rate of the crystal can be obtained. Simultaneously, the volume increase rate of the crystal can be obtained based on the lifting speed of the lifting rod, ultimately yielding the crystal growth rate curve. Repeating the above steps, the crystal growth rate curves at the second, third, fourth, and fifth temperatures can be obtained sequentially, as shown below. Figure 5 As shown, the first temperature represents the temperature at which the melting point decreases by 1°C, the second temperature represents the temperature at which the melting point decreases by 2°C, and so on. Therefore, it can be seen that as the temperature gradually increases (approaching the melting point), the higher the temperature, the slower the crystal growth rate.

[0059] Similarly, the furnace temperature can be raised above the melting point, and the above-described volume change measurement process can be repeated to obtain the crystal at the sixth, seventh, eighth, ninth, and tenth temperatures, such as... Figure 6 As shown, the sixth temperature represents the temperature at which the melting point increases by 1°C, the seventh temperature represents the temperature at which the melting point increases by 2°C, and so on. Therefore, it can be seen that as the temperature gradually increases (away from the melting point), the higher the temperature, the faster the crystal melts.

[0060] It is worth noting that the melting rate or growth rate of crystals near the melting point is highly sensitive to temperature. Every 1°C increase or decrease will cause a significant change in the melting or growth rate of the crystal. Therefore, based on the growth kinetics of different crystals and experience, the furnace temperature can be determined by combining the melting rate or growth rate of the crystal with empirical value curves, and the temperature corresponding to different melting rates or growth rates can be marked.

[0061] In some embodiments of this application, step S300 includes: determining the image grayscale of the target area inside the furnace at the temperature based on at least one image at the above temperature; determining the image grayscale of the target area inside the furnace at at least another temperature based on at least one image at at least another temperature; correspondingly, step S400 includes: determining the grayscale change curve of the image grayscale of the target area within the target temperature range based on the obtained image grayscale and the temperature value corresponding to each image grayscale.

[0062] Optional, such as Figure 7As shown, a target area within the field of view (the area within the black box in the figure) can be selected, and the image grayscale of the target area at different temperatures can be determined. Then, based on the obtained image grayscale and the temperature value corresponding to each image grayscale, the grayscale variation curve of the target area within the target temperature range can be determined. Optionally, the image grayscale can be represented by integrating the pixel grayscale of the target area to obtain the corresponding integral value. Optionally, the grayscale range of a typical 8-bit detector is 0–255. This embodiment uses a 16-bit detector for better measurement, therefore the corresponding maximum grayscale is... In practical applications, for better performance, this embodiment utilizes one less bit; therefore, the corresponding maximum grayscale range is... Thus, we can obtain the following: Figure 8 The grayscale variation curve shown.

[0063] This application also provides a method for measuring the temperature of a crystal growth furnace, comprising: acquiring a target image containing a target region inside the furnace; determining the image grayscale of the target region inside the furnace based on the target image; and determining the furnace temperature based on the image grayscale and the grayscale change curve obtained by the method described in the preceding embodiments.

[0064] The above measurement method, by measuring the image grayscale of the target area inside the furnace and combining it with the calibrated grayscale change curve of the target area within the target temperature range, can quickly infer the furnace temperature. This helps avoid the purchase of expensive equipment, simplifies equipment operation, and significantly reduces costs.

[0065] This application embodiment also provides a measuring device for a crystal growth furnace, wherein the side wall of the crystal growth furnace is provided with an observation window for convenient acquisition of images of the crystal inside the furnace, such as... Figure 9 As shown, the measuring device includes: a first acquisition module configured to acquire the volume change rate of a crystal at at least two temperatures within a target temperature range, wherein the target temperature range includes the melting point of the crystal; a first determination module connected to the first acquisition module configured to determine the temperature values ​​of at least two temperatures based on the acquired volume change rate and a pre-stored empirical curve of the volume change rate of the crystal within the target temperature range; a second acquisition module connected to the first determination module configured to acquire temperature evaluation values ​​of a target area within the furnace at at least two temperatures; and a second determination module connected to the second acquisition module configured to determine the correspondence between the temperature evaluation value of the target area and the temperatures within the target temperature range based on the acquired temperature evaluation value and the temperature values ​​of the at least two temperatures.

[0066] The aforementioned measuring device, before measuring the furnace temperature, can first determine the temperature values ​​of the at least two temperatures by measuring the volume change rate of the crystal at at least two temperatures, and then by combining this with empirical curves of volume change rate versus temperature obtained through human observation. Next, the temperature evaluation values ​​of the target area within the furnace at these at least two temperatures are used to calibrate the temperature inside the crystal growth furnace. This not only facilitates subsequent temperature measurement of the crystal growth furnace but also avoids the purchase of expensive equipment, simplifies equipment operation, and significantly reduces costs.

[0067] In some embodiments of this application, see also [link to previous document]. Figure 9 The measuring device further includes: a third acquisition module configured to acquire a temperature evaluation value of the target area; and a third determination module connected to the third acquisition module and the second determination module, configured to determine the temperature inside the crystal growth furnace based on the temperature evaluation value and its correspondence. Optionally, the temperature evaluation value can be the image grayscale of the target area inside the furnace.

[0068] This application also provides a computer-readable storage medium for storing a computer program that causes a computer to perform steps in the calibration method or measurement method described in the preceding embodiments.

[0069] It should be noted that the numbers used to describe and claim certain embodiments of this application, representing quantities or properties, should be understood to be modified in some cases by the terms "approximately," "about," "approximately," or "essentially." For example, unless otherwise stated, "approximately," "about," "approximately," or "essentially" can indicate a variation of ±20% of the value they describe. Accordingly, in some embodiments, the numerical parameters used in the specification and claims are approximate values, which may be changed according to the characteristics required by individual embodiments. In some embodiments, numerical parameters should take into account specified significant digits and employ a general method of digit reservation. Although the numerical ranges and parameters used to confirm their breadth of range in some embodiments of this application are approximate values, in specific embodiments, such numerical values ​​are set as precisely as feasible.

[0070] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0071] The embodiments described above are merely illustrative of several implementations of the present invention, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the invention patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these all fall within the protection scope of the present invention. Therefore, the protection scope of this invention patent should be determined by the appended claims.

Claims

1. A method for temperature calibration of a crystal growth furnace, characterized in that, The method includes: The volume change rate of the crystal at at least two temperatures within a target temperature range is obtained by using the crystal growth image and the crystal pulling speed; the process of obtaining the volume change rate of the crystal at at least two temperatures within a target temperature range by using the crystal growth image and the crystal pulling speed includes: Acquire a first image and a second image of the crystal at a temperature within the target temperature range, spaced apart by a preset time. The lateral change rate of the crystal is determined based on the first image, the second image, and the preset time. Obtain the longitudinal velocity of the crystal; The volume change rate of the crystal at this temperature is determined based on the longitudinal change rate and the transverse change rate. Repeat the above steps to obtain the rate of volume change of the crystal at at least another temperature within the target temperature range; The target temperature range includes the melting point of the crystal; Based on the obtained volume change rate and the pre-stored empirical value curve of the crystal's volume change rate within the target temperature range, the temperature values ​​of the at least two temperatures are determined; wherein, the empirical value curve of the volume change rate is obtained by pre-measuring the volume change rate of the crystal at different set temperatures and plotting it in conjunction with the corresponding set temperatures, and the volume change rate of the crystal is obtained by combining the crystal growth image with the crystal pulling speed; the furnace temperature of the crystal growth furnace is controlled by controlling its heating power to make the furnace temperature higher or lower than the melting point of the crystal; Acquire image grayscale values ​​of the target area inside the furnace at at least two temperatures; Based on the obtained image grayscale and the temperature values ​​of the at least two temperatures, determine the correspondence between the image grayscale of the target region and each temperature within the target temperature range.

2. The method according to claim 1, characterized in that, The side wall of the crystal growth furnace is provided with an observation window for observing the crystals inside the furnace.

3. The method according to claim 1 or 2, characterized in that, The target temperature range is the temperature range of ±5℃ from the melting point temperature.

4. The method according to claim 1 or 2, characterized in that, The rate of volume change includes at least one of the crystal growth rate and the crystal melting rate.

5. The method according to claim 1, characterized in that, The step of obtaining the image grayscale of the target area inside the furnace at the at least two temperatures includes: determining the image grayscale of the target area inside the furnace at the temperature based on at least one image at the temperature; and determining the image grayscale of the target area inside the furnace at the at least other temperature based on at least one image at the at least other temperature. Correspondingly, The step of determining the correspondence between the temperature evaluation value of the target area and each temperature within the target temperature range based on the obtained temperature evaluation value and the temperature values ​​of the at least two temperatures includes: Based on the obtained image grayscale and the temperature value corresponding to each image grayscale, the grayscale change curve of the target region within the target temperature range is determined.

6. A method for measuring the temperature of a crystal growth furnace, characterized in that, include: Obtain a target image containing the target area inside the furnace; Determine the image grayscale of the target area inside the furnace based on the target image; The furnace temperature is determined based on the image grayscale and the grayscale change curve obtained by the method as described in claim 5.

7. A measuring device for a crystal growth furnace, characterized in that, For implementing the method as described in claims 1-5, comprising: The first acquisition module is configured to acquire the volume change rate of the crystal at at least two temperatures within a target temperature range by using the growth image of the crystal and the pulling speed of the crystal, wherein the target temperature range includes the melting point of the crystal; A first determining module, connected to the first acquiring module, is configured to determine the temperature values ​​of the at least two temperatures based on the obtained volume change rate and a pre-stored empirical value curve of the crystal's volume change rate within the target temperature range; wherein, the empirical value curve of the volume change rate is obtained by pre-measuring the volume change rate of the crystal at different set temperatures and plotting it in conjunction with the corresponding set temperatures, and the volume change rate of the crystal is obtained by determining the lateral change rate of the crystal from the crystal's growth image and then combining it with the crystal's lifting speed; The second acquisition module, connected to the first determination module, is configured to acquire the image grayscale of the target area inside the furnace at the at least two temperatures. The second determining module, connected to the second acquiring module, is configured to determine the correspondence between the image grayscale of the target area and each temperature within the target temperature range based on the acquired image grayscale and the temperature values ​​of the at least two temperatures.

8. The apparatus according to claim 7, characterized in that, Also includes: The third acquisition module is configured to acquire the image grayscale of the target region; The third determining module, connected to the third acquiring module and the second determining module, is configured to determine the temperature inside the crystal growth furnace based on the image grayscale and the corresponding relationship.

9. A computer-readable storage medium, characterized in that, Used to store computer programs that cause a computer to perform the steps of the method as claimed in any one of claims 1 to 5 or the method as claimed in claim 6.

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