Early warning management and control method for crystal bar production quality

Abstract

The invention belongs to the technical field of crystal bar production, and provides a crystal bar production quality early warning management and control method comprising the following steps: detecting the minority carrier lifetime and resistivity of a currently drawn crystal bar, and calculating the ratio of the minority carrier lifetime and resistivity to obtain a minority carrier resistance ratio; judging whether the currently drawn crystal bar is a circulating bar or a finished bar; according to the results of the previous two steps, displaying early warnings with different colors on the production board; for early warning of different colors, corresponding measures are taken for management, control and improvement. According to the attenuation performance or process performance of the minority carrier resistance ratio of the crystal bar, the whole production process of the crystal bar is tracked in real time in a mode of displaying different colors for early warning through the attenuation level, so that corresponding measures are taken for management, control and improvement, furnace shutdown loss and crystal bar return waste caused by too short minority carrier lifetime can be effectively reduced, and the production efficiency is improved. And the production cost of the crystal bar is reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of crystal rod production, and in particular to a method for early warning control of crystal rod production quality. Background Art

[0002] Ingots are a material used in the manufacture of semiconductor devices, and their quality directly impacts their performance and reliability. Ingot quality is primarily characterized by the minority carrier lifetime (short for the lifetime of minority carriers), which is closely related to the purity of the raw material and the impurity content within the furnace. The higher the minority carrier lifetime, the higher the conductivity of the ingot and the better the performance of the semiconductor device. Therefore, during the ingot drawing process, minority carrier lifetime testing is necessary to ensure accurate control of ingot production quality.

[0003] Currently, the quality control method for ingot production is to halt production when the minority carrier lifetime of the ingot reaches a preset standard, and then investigate and analyze the cause of the abnormality. However, this control method, which relies solely on results without considering the process, suffers from untimely feedback, significant downtime losses, and wasteful return of ingots due to low minority carrier lifetimes, further increasing ingot production costs. Summary of the Invention

[0004] In response to the shortcomings of the existing technology, the present invention provides an early warning control method for crystal rod production quality to solve the problem that the existing control method has untimely information feedback, causes huge furnace shutdown losses and wastes of crystal rods due to the low minority carrier lifetime, thereby increasing the production cost of crystal rods.

[0005] To achieve the above objectives, the present invention provides the following technical solutions:

[0006] A method for early warning control of crystal ingot production quality includes the following steps:

[0007] S1. Detecting the minority carrier lifetime and resistivity of the currently pulled ingot, and calculating the ratio of the two to obtain the minority carrier resistance ratio;

[0008] S2, determining whether the currently drawn crystal ingot is a circulating ingot or a finished ingot;

[0009] S3. Display warnings of different colors on the production dashboard based on the results of S1 and S2;

[0010] S4. Take corresponding measures to improve management and control for warnings of different colors.

[0011] In one embodiment disclosed in the present application, the step of “S1, detecting the minority carrier lifetime and resistivity of the currently pulled crystal ingot, and calculating the ratio thereof to obtain the minority carrier resistance ratio” includes the following steps:

[0012] S11, marking the currently pulled crystal ingot with first to eleventh break lines, wherein the sections outside the first and eleventh break lines are the two ends of the crystal ingot to be cut off, and the length of the section between the first and second break lines is 1 / 10 of the length of the section between the first and eleventh break lines;

[0013] S12, cutting the crystal ingot along the first cutting line and the second cutting line to obtain a first short ingot;

[0014] S13, detecting the minority carrier lifetime and resistivity at the end surface where the first short rod coincides with the second truncation line;

[0015] S14. Calculate the minority carrier resistance ratio of the crystal rod according to the following formula:

[0016] Minority carrier resistance ratio = minority carrier lifetime / resistivity

[0017] Wherein, the unit of minority carrier lifetime is μs, and the unit of resistivity is Ω·cm.

[0018] In one embodiment disclosed in the present application, the step of “S2, determining whether the currently pulled crystal ingot is a circulating ingot or a finished ingot” includes the following steps:

[0019] S21, weighing the currently pulled crystal ingot, and summing its weight with the remaining material in the furnace;

[0020] S22. If "the weight of the currently drawn crystal rod + the remaining material in the furnace" ≥ the preset weight, the currently drawn crystal rod is a circulating rod; otherwise, it is a finished rod.

[0021] In one embodiment disclosed in the present application, the preset weight is 600 kg.

[0022] In one embodiment disclosed in the present application, the step of “S3, displaying warnings of different colors on the production dashboard based on the results of S1 and S2” includes the following steps:

[0023] S31. If the currently pulled crystal ingot is a finished ingot and its minority carrier resistance ratio is less than a first preset ratio, or is a circulating ingot and its minority carrier resistance ratio is less than a second preset ratio, a red warning is displayed on the production dashboard;

[0024] S32. If the currently pulled crystal ingot is a circulating ingot and its minority carrier resistance ratio is ≥ the second preset ratio and < the third preset ratio, a yellow warning is displayed on the production dashboard;

[0025] S33. If the currently pulled crystal ingot is a circulating ingot and its minority carrier resistance ratio is ≥ the third preset ratio and < the fourth preset ratio, a green warning is displayed on the production dashboard;

[0026] S34. If the currently pulled crystal rod is a finished rod and its minority carrier resistance ratio is ≥ the first preset ratio or is a circulating rod and its minority carrier resistance ratio is ≥ the fourth preset ratio, no warning is displayed on the production dashboard.

[0027] In one embodiment disclosed in the present application, the first preset ratio is 1000;

[0028] The second preset ratio is 2000;

[0029] The third preset ratio is 2300;

[0030] The fourth preset ratio is 3000.

[0031] In one embodiment disclosed in the present application, the “S4, taking corresponding measures to improve management and control for warnings of different colors” includes the following steps:

[0032] S41. When the production board shows a red warning, no more feeding will be done and the corresponding furnace will be stopped;

[0033] S42. When the production dashboard displays a yellow warning, recheck the minority carrier lifetime and resistivity of the currently pulled ingot to confirm that the test is correct. Then, check the batches of raw and recycled materials from the corresponding furnace and put them into other furnaces to pull ingots to check whether there is a common minority carrier resistivity attenuation rate greater than 30% in each batch and to determine the source of contamination.

[0034] S43. When the production board displays a green warning, recheck the minority carrier lifetime and resistivity of the currently drawn crystal rod to confirm that the detection is correct, and check whether the minority carrier resistance ratio attenuation rate of each rod produced by the corresponding furnace is greater than 30%. If it is less than 30%, it is a gradual attenuation. Pure virgin material is added to the corresponding furnace to dilute the existing pollutants in the furnace, or normal re-addition is performed to continue pulling the crystal rod and allow its minority carrier resistance ratio to decay naturally until the production board displays a red warning and proceed according to S41. If it is greater than 30%, it is a sudden decrease and proceed according to S42.

[0035] In one embodiment disclosed in the present application, in S42:

[0036] If there is a common feature that the minority carrier resistance ratio attenuation rate is greater than 30%, it indicates that the batch of virgin and recycled materials has been contaminated and must be stopped immediately;

[0037] If there is no common feature of minority carrier resistance ratio attenuation rate > 30%, it indicates that contaminants have been introduced during the operation process and the operation process must be standardized.

[0038] In one embodiment disclosed in the present application, in S43:

[0039] If the gradual attenuation occurs during the first five recharging processes of the corresponding furnace, pure virgin material should be added to the furnace to dilute the existing pollutants in the furnace;

[0040] If the gradual decay occurs during the sixth and subsequent recharging of the corresponding furnace, continue to recharge the furnace normally and continue to pull the crystal rod, allowing its minority carrier resistance ratio to decay naturally until the production board displays a red warning and proceed according to S41.

[0041] In one embodiment disclosed in this application, the following steps are also included:

[0042] S5. During the first eight recharging processes of the corresponding furnace, S1 to S4 are repeatedly executed; during the ninth and subsequent recharging processes of the corresponding furnace, S1 to S3 and S41 are repeatedly executed.

[0043] Compared with the prior art, the present invention has the following beneficial effects:

[0044] Based on the attenuation or process performance of the minority carrier resistance ratio of the crystal ingot, the entire production process of the crystal ingot is tracked in real time by displaying different color warnings according to the attenuation level, so that corresponding measures can be taken for management and improvement. This can effectively reduce the shutdown losses caused by too low minority carrier lifetime and the waste of crystal ingot return, thereby reducing the production cost of the crystal ingot. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the following is a brief introduction to the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0046] Figure 1 It is a schematic diagram of the steps of the present invention. DETAILED DESCRIPTION

[0047] Hereinafter, only certain exemplary embodiments are briefly described. As will be appreciated by those skilled in the art, the described embodiments may be modified in various ways without departing from the spirit or scope of the present invention. Therefore, the drawings and description are to be considered as illustrative in nature and not restrictive.

[0048] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like to indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention.

[0049] 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 the technical features being referred to. Thus, a feature identified as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, "plurality" means two or more, unless otherwise specifically defined.

[0050] In the present invention, unless otherwise expressly specified or limited, terms such as "mounted," "connected," "connect," and "fixed" should be understood broadly. For example, they may refer to fixed connection, detachable connection, or integration; they may refer to direct connection or indirect connection through an intermediate medium; they may refer to internal communication between two components or interaction between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on specific circumstances.

[0051] In the present invention, unless otherwise expressly specified or limited, a first feature being "above" or "below" a second feature may include the first and second features being in direct contact, or may include the first and second features being in contact not directly but through another feature between them. Furthermore, a first feature being "above," "above," and "above" a second feature may include the first feature being directly above or obliquely above the second feature, or may simply mean that the first feature is higher in level than the second feature. A first feature being "below," "below," and "below" a second feature may include the first feature being directly below or obliquely below the second feature, or may simply mean that the first feature is lower in level than the second feature.

[0052] The disclosure below provides many different embodiments or examples to realize different structures of the present invention. In order to simplify the disclosure of the present invention, the parts and settings of specific examples are described below. Of course, they are only examples, and the purpose is not to limit the present invention.

[0053] The embodiments of the present invention are described in detail below with reference to the accompanying drawings.

[0054] See also Figure 1As shown, the present invention provides a method for early warning control of crystal ingot production quality, comprising the following steps:

[0055] S1. Detect the minority carrier lifetime and resistivity of the currently pulled crystal rod, and calculate the ratio of the two to obtain the minority carrier resistance ratio.

[0056] Specifically, the ends of a newly pulled ingot are pointed, and its diameter gradually decreases, making it impossible to directly measure the minority carrier lifetime and resistivity. Therefore, it is necessary to cut off the ends and then divide the remaining part into 10 equal sections. The minority carrier lifetime and resistivity at the second cut surface (named B surface) are used to represent the minority carrier lifetime and resistivity of the entire ingot. The detection and calculation process is as follows:

[0057] S11, marking the currently pulled crystal ingot with first to eleventh break lines, wherein the sections outside the first and eleventh break lines are the two ends of the crystal ingot to be cut off, and the length of the section between the first and second break lines is 1 / 10 of the length of the section between the first and eleventh break lines;

[0058] S12, cutting the crystal ingot along the first cutting line and the second cutting line to obtain a first short ingot;

[0059] S13, detecting the minority carrier lifetime and resistivity at the end surface where the first short rod coincides with the second truncation line;

[0060] S14. Calculate the minority carrier resistance ratio of the crystal rod according to the following formula:

[0061] Minority carrier resistance ratio = minority carrier lifetime / resistivity

[0062] Wherein, the unit of minority carrier lifetime is μs, and the unit of resistivity is Ω·cm.

[0063] For example, if the minority carrier lifetime of a short rod in the first section is 7500 μs and the resistivity is 1.3 Ω·cm, then its minority carrier resistance ratio is 7500 / 1.3=5769 (this ratio has no unit).

[0064] S2. Determine whether the currently drawn crystal rod is a circulating rod or a finished rod.

[0065] Specifically, the circulating rod is the ingot produced between the start of each furnace drawing and each recharging, and the finished rod is the last ingot produced by the furnace (also known as the tail ingot). For example, a furnace may produce a total of 100 ingots after multiple rechargings, of which rods 1 to 99 are circulating rods, and the last rod is the finished ingot. The judgment process is as follows:

[0066] S21, weighing the currently pulled crystal ingot, and summing its weight with the remaining material in the furnace;

[0067] S22. If "the weight of the currently drawn crystal rod + the remaining material in the furnace" ≥ the preset weight, the currently drawn crystal rod is a circulating rod; otherwise, it is a finished rod.

[0068] In this embodiment, the preset weight is 600kg. During the pulling process, each furnace repeatedly refills with silicon material to ensure continuous ingot production until the crucible reaches a point where no further ingot can be pulled. As the pulling process progresses, the impurity content in the furnace increases, significantly impacting the ingot's minority carrier lifespan. Normally, each furnace holds 950kg of silicon material at the start of the pulling process. When the sum of these values ​​is ≥600kg, the currently drawn ingot is a circulating ingot (not a final ingot). If the minority carrier resistance ratio of the ingot is abnormally low, a warning is issued to stop the process to avoid losses resulting from further refills. When the sum is <600kg, the currently drawn ingot is a final ingot (a final ingot) and no further refills are required, so the preset weight is set at 600kg.

[0069] S3. Based on the results of S1 and S2, different colored warnings are displayed on the production dashboard.

[0070] Specifically, the warning colors are divided into the following categories:

[0071] S31. If the currently pulled crystal ingot is a finished ingot and its minority carrier resistance ratio is less than a first preset ratio, or is a circulating ingot and its minority carrier resistance ratio is less than a second preset ratio, a red warning is displayed on the production dashboard;

[0072] S32. If the currently pulled crystal ingot is a circulating ingot and its minority carrier resistance ratio is ≥ the second preset ratio and < the third preset ratio, a yellow warning is displayed on the production dashboard;

[0073] S33. If the currently pulled crystal ingot is a circulating ingot and its minority carrier resistance ratio is ≥ the third preset ratio and < the fourth preset ratio, a green warning is displayed on the production dashboard;

[0074] S34. If the currently pulled crystal rod is a finished rod and its minority carrier resistance ratio is ≥ the first preset ratio or is a circulating rod and its minority carrier resistance ratio is ≥ the fourth preset ratio, no warning is displayed on the production dashboard.

[0075] In this embodiment, the first preset ratio is 1000, the second preset ratio is 2000, the third preset ratio is 2300, and the fourth preset ratio is 3000. The lower the minority carrier resistance ratio, the higher the risk of slow minority carrier recombination and abnormal conductivity characteristics in the crystal rod, and the greater the negative impact on the electrical performance, reliability, and manufacturing yield of the semiconductor device. Therefore, the minority carrier resistance ratio is an important early warning indicator for measuring crystal rod quality. When the minority carrier resistance ratio of the finished rod is less than 1000 or the minority carrier resistance ratio of the circulating rod is less than 2000, it indicates that the impurity content has reached an unacceptable level, and such crystal rods are scrapped for single crystal pulling. For this reason, a red warning is displayed on the production dashboard to reduce the production of such crystal rods, thereby reducing the waste of return cuts due to low minority carrier lifetimes during the production process. When the minority carrier resistance ratio of a circulating rod is ≥2000 and <2300, this indicates that the ingot requires special attention for process contamination. The minority carrier resistance ratio of the next ingot drawn may be lower than 2000, resulting in a high probability of failure and scrapping. Therefore, a yellow warning is displayed on the production dashboard. When the minority carrier resistance ratio of a circulating rod is ≥2300 and <3000, this indicates that the minority carrier resistance ratio of the ingot is beginning to decline, requiring review of the minority carrier lifetime and resistivity to prepare for the next step. Therefore, a green warning is displayed on the production dashboard. When the minority carrier resistance ratio of a finished ingot is ≥1000 or the minority carrier resistance ratio of a circulating ingot is ≥3000, this indicates that the ingot is normal. Therefore, no warning is displayed on the production dashboard.

[0076] S4. Take corresponding measures to improve management and control for warnings of different colors.

[0077] Specifically, the corresponding measures for different color warnings are as follows:

[0078] S41. When the production dashboard displays a red warning, recharging is discontinued and the corresponding furnace is shut down. Controlling the corresponding furnace by stopping recharging and shutting down the furnace can reduce the back-cut losses caused by the low minority carrier lifetime of the pulled ingot after recharging.

[0079] S42. When the production board displays a yellow warning, recheck the minority carrier lifetime and resistivity of the currently drawn crystal rod to confirm that the detection is correct. Then check the batches of raw materials and recycled materials from the corresponding furnace, and put them into other furnaces to pull crystal rods to detect whether there is a common minority carrier resistance ratio attenuation rate greater than 30% for each batch of rods and determine the source of contamination. When the production board shows a yellow warning, it is necessary to recheck the minority carrier lifetime and resistivity of the currently drawn crystal rod to confirm that the detection is correct. Then, the same batch of raw materials and recycled materials are put into other furnaces to draw crystal rods, and then check whether the minority carrier resistance ratio attenuation rate between each rod is more than 30% (minority carrier resistance ratio attenuation means that the minority carrier resistance ratio between multiple crystal rods produced by the same furnace will show a downward trend due to the increase of impurity content or pollutants in the furnace). Then, under this premise, check the pollution source (mainly focus on checking whether there is process pollution, that is, it is necessary to find the cause of the attenuation of the minority carrier resistance ratio of the crystal rod. These causes may be the introduction of pollutants in the raw materials and recycled materials of this batch, or the introduction of pollutants into the furnace during the operation process, causing quality problems. Specifically, it is necessary to check whether there is process pollution problem in the raw materials, and at the same time check whether there are any problems in the entire output, collection, circulation, cleaning, crushing, packaging, loading, and furnace feeding of the recycled materials of this batch). That is:

[0080] If the minority carrier resistivity decay rate is greater than 30%, this indicates that contaminants have been introduced into the batch of virgin and recycled materials and they must be immediately discontinued. For virgin materials, you can file a complaint with the supplier regarding quality issues and request a replacement or return, along with a corresponding quality claim. For recycled materials, they can be re-cleaned and tested for surface metal content before they can be reused.

[0081] If there's no common trait of a minority carrier resistivity attenuation rate greater than 30%, it indicates contaminants were introduced during the operation and must be regulated. For example, this could be due to abnormalities in cleaning, crushing, or material preparation equipment, improper environmental protection, or failure to adhere to standard controls during operation. In this case, training and assessment can be conducted for the employee or the responsible location.

[0082] S43. When the production dashboard displays a green warning, recheck the minority carrier lifetime and resistivity of the currently pulled ingot to confirm the accuracy of the test. Also, check whether the minority carrier resistivity decay rate of each ingot produced by the corresponding furnace is >30%. If <30%, it indicates gradual decay. Add pure virgin material to the corresponding furnace to dilute the existing contaminants, or re-add material as normal, and continue pulling the ingot, allowing the minority carrier resistivity to decay naturally until the production dashboard displays a red warning. Follow S41. If >30%, it indicates a sudden decrease, and follow S42. The minority carrier resistivity decay rate is the ratio (usually expressed as a percentage) of the difference in minority carrier resistivity between the previous and next ingots produced in the same furnace, or between the current and next ingots, relative to the minority carrier resistivity of the previous or current ingot. For example, if the minority carrier resistivity ratios of the first to fourth ingots are 8000, 7000, 5500, and 5000, respectively, the minority carrier resistivity decay rate between any two adjacent ingots does not exceed 30%, indicating gradual decay, also known as normal decay. In this case, pure virgin material can be used during recharging, without any recycled material (because virgin material is cleaner and poses less contamination risk than recycled material, while recycled material is recycled and has a higher impurity content, posing a greater contamination risk than virgin material). This approach comprehensively reduces or dilutes existing contaminants in the furnace, thereby reducing the probability of decay in the minority carrier resistivity of the resulting ingots, stabilizing the minority carrier lifespan of the ingots to keep the minority carrier resistivity below 2000 without requiring a production stop. This allows for the production of one or more additional ingots, increasing furnace output. Alternatively, recharging can be continued as usual, allowing the minority carrier resistivity to decay naturally (without any manual intervention) until a red alert appears on the production dashboard, prompting a stop in S41. If the minority carrier resistivity of the first and second ingots is 8000 and 5000, respectively, this represents a 37.5% decrease, which is greater than 30%, indicating a sudden decrease, indicating excessive decay. At this time, it is necessary to check the corresponding furnace's raw material and recycled material batches according to S42, and put them into other furnaces to pull crystal rods to detect whether there is a common minority carrier resistance ratio attenuation rate greater than 30% in each rod and to determine the source of pollution.

[0083] In S43, if gradual decay occurs during the first five recharging cycles for the corresponding furnace, pure virgin material is added to that furnace to dilute existing contaminants. If gradual decay occurs during the sixth or subsequent recharging cycles for that furnace, normal recharging is continued for that furnace, allowing the minority carrier resistance ratio to naturally decrease until a red alert appears on the production dashboard, in which case S41 is performed. Each furnace is normally recharged approximately ten times (referred to in the industry as "10 recharging cycles"). When gradual decay occurs between 1 and 5 recharging cycles, the concentration of existing contaminants in the furnace is low, and pure virgin material is effective in diluting the recharging cycle. If gradual decay occurs after 5 recharging cycles, the contaminants in the furnace have reached a certain level, and pure virgin material is ineffective in diluting the contaminants. Therefore, normal recharging is resumed, and ingot pulling is continued, allowing the minority carrier resistance ratio of the resulting ingots to naturally decrease until S31 appears, indicating a red alert appears on the production dashboard, in which case S41 is performed to halt the process.

[0084] The above-mentioned early warning control method for crystal ingot production quality also includes the following steps:

[0085] S5. Repeat S1 to S4 during the first 8 times of recharging of the corresponding furnace; repeat S1 to S3 and S41 during the 9th and subsequent times of recharging of the corresponding furnace. When the number of times of recharging of the corresponding furnace is relatively early, that is, within 8 times, the impurity deposition and pollutants in the furnace are relatively small. At this time, it is necessary to repeat S1 to S4 to control the production quality of the crystal rod and implement active intervention. During the recharging process after 8 times, the impurity deposition and pollutants in the furnace are relatively high. When the production board shows green and yellow warnings, it will no longer be controlled and the crystal rod will continue to be pulled until the minority carrier resistance ratio of the produced crystal rod naturally decays and the situation of S31 occurs. Then, according to S41, the pulling is stopped.

[0086] It has been verified that after adopting the above-mentioned early warning and control methods, the annual shutdown losses caused by low minority carrier lifetime are reduced by about 2.2 million yuan, and the waste of crystal rod interception is reduced by about 7.8 million yuan.

[0087] In summary, the present invention tracks the entire production process of the crystal rod in real time by displaying different color warnings according to the attenuation level based on the attenuation performance or process performance of the minority carrier resistance ratio of the crystal rod, so as to take corresponding measures for management and improvement. It can effectively reduce the shutdown losses caused by too low minority carrier lifetime and the waste of crystal rod return, thereby reducing the production cost of the crystal rod.

[0088] The above embodiments are only preferred embodiments of the present invention and are not limitations on the technical solutions of the present invention. Any technical solution that can be implemented on the basis of the above embodiments without creative work should be deemed to fall within the scope of protection of the patent of the present invention.

Claims

1. A method for early warning control of crystal ingot production quality, characterized in that: The following steps are involved: S1. Detecting the minority carrier lifetime and resistivity of the currently pulled ingot, and calculating the ratio of the two to obtain the minority carrier resistance ratio; S2, determining whether the currently drawn crystal ingot is a circulating ingot or a finished ingot; S3. Display warnings of different colors on the production dashboard based on the results of S1 and S2; S4. Take corresponding measures to improve management and control for warnings of different colors.

2. The method for early warning control of crystal ingot production quality according to claim 1, characterized in that: The step of "S1, detecting the minority carrier lifetime and resistivity of the currently pulled crystal rod, and calculating the ratio of the lifetime and resistivity to obtain the minority carrier resistance ratio" includes the following steps: S11, marking the currently pulled crystal ingot with first to eleventh break lines, wherein the sections outside the first and eleventh break lines are the two ends of the crystal ingot to be cut off, and the length of the section between the first and second break lines is 1 / 10 of the length of the section between the first and eleventh break lines; S12, cutting the crystal ingot along the first cutting line and the second cutting line to obtain a first short ingot; S13, detecting the minority carrier lifetime and resistivity at the end surface where the first short rod coincides with the second truncation line; S14. Calculate the minority carrier resistance ratio of the crystal rod according to the following formula: Minority carrier resistance ratio = minority carrier lifetime / resistivity Wherein, the unit of minority carrier lifetime is μs, and the unit of resistivity is Ω·cm.

3. The method for early warning control of crystal ingot production quality according to claim 1 or 2, characterized in that: The "S2, determining whether the currently drawn crystal rod is a circulating rod or a finished rod" includes the following steps: S21, weighing the currently pulled crystal ingot, and summing its weight with the remaining material in the furnace; S22. If "the weight of the currently drawn crystal ingot + the remaining material in the furnace" ≥ the preset weight, the currently drawn crystal ingot is a circulating ingot; otherwise, it is a finished ingot.

4. The method for early warning control of crystal ingot production quality according to claim 3, characterized in that: The preset weight is 600 kg.

5. The method for early warning control of crystal ingot production quality according to claim 4, characterized in that: The step "S3, displaying warnings of different colors on the production dashboard based on the results of S1 and S2" includes the following steps: S31. If the currently pulled crystal ingot is a finished ingot and its minority carrier resistance ratio is less than a first preset ratio, or is a circulating ingot and its minority carrier resistance ratio is less than a second preset ratio, a red warning is displayed on the production dashboard; S32. If the currently pulled crystal ingot is a circulating ingot and its minority carrier resistance ratio is ≥ the second preset ratio and < the third preset ratio, a yellow warning is displayed on the production dashboard; S33. If the currently pulled crystal ingot is a circulating ingot and its minority carrier resistance ratio is ≥ the third preset ratio and < the fourth preset ratio, a green warning is displayed on the production dashboard; S34. If the currently pulled crystal rod is a finished rod and its minority carrier resistance ratio is ≥ the first preset ratio or is a circulating rod and its minority carrier resistance ratio is ≥ the fourth preset ratio, no warning is displayed on the production dashboard.

6. The method for early warning and control of crystal ingot production quality according to claim 5, characterized in that: The first preset ratio is 1000; The second preset ratio is 2000; The third preset ratio is 2300; The fourth preset ratio is 3000.

7. The method for early warning control of crystal ingot production quality according to claim 5 or 6, characterized in that: The aforementioned "S4. Taking corresponding measures to improve management and control for warnings of different colors" includes the following steps: S41. When the production board shows a red warning, no more feeding will be done and the corresponding furnace will be stopped; S42. When the production dashboard displays a yellow warning, recheck the minority carrier lifetime and resistivity of the currently pulled ingot to confirm that the test is correct. Then, check the batches of raw and recycled materials from the corresponding furnace and put them into other furnaces to pull ingots to check whether there is a common minority carrier resistivity attenuation rate greater than 30% in each batch and to determine the source of contamination. S43. When the production board displays a green warning, recheck the minority carrier lifetime and resistivity of the currently drawn crystal rod to confirm that the detection is correct, and check whether the minority carrier resistance ratio attenuation rate of each rod produced by the corresponding furnace is greater than 30%. If it is less than 30%, it is a gradual attenuation. Pure virgin material is added to the corresponding furnace to dilute the existing pollutants in the furnace, or normal re-addition is performed to continue pulling the crystal rod and allow its minority carrier resistance ratio to decay naturally until the production board displays a red warning and proceed according to S41. If it is greater than 30%, it is a sudden decrease and proceed according to S42.

8. The method for early warning control of crystal ingot production quality according to claim 7, characterized in that: In said S42: If there is a common feature that the minority carrier resistance ratio attenuation rate is greater than 30%, it indicates that the batch of virgin and recycled materials has been contaminated and must be stopped immediately; If there is no common feature of minority carrier resistance ratio attenuation rate > 30%, it indicates that contaminants have been introduced during the operation process and the operation process must be standardized.

9. The method for early warning control of crystal ingot production quality according to claim 7, characterized in that: In said S43: If the gradual attenuation occurs during the first five recharging processes of the corresponding furnace, pure virgin material should be added to the furnace to dilute the existing pollutants in the furnace; If the gradual decay occurs during the sixth and subsequent recharging of the corresponding furnace, continue to recharge the furnace normally and continue to pull the crystal rod, allowing its minority carrier resistance ratio to decay naturally until the production board displays a red warning and proceed according to S41.

10. The method for early warning control of crystal ingot production quality according to claim 8 or 9, characterized in that: The following steps are also included: S5. During the first eight recharging processes of the corresponding furnace, S1 to S4 are repeatedly executed; during the ninth and subsequent recharging processes of the corresponding furnace, S1 to S3 and S41 are repeatedly executed.

Images