Polysilicon deposition air inlet device and control method based on silicon core rod growth characteristics

Abstract

The present invention relates to the technical field of polysilicon deposition used as the main raw material in the semiconductor or solar energy industry, and in particular to a polysilicon deposition air intake device and a control method based on the growth characteristics of silicon core rods. The control method comprises determining and obtaining abnormal growth area data and overall growth rate data of the silicon core rods based on the uniformity of the surface temperature distribution of the silicon core rods within a first preset time period and / or the uniformity of the growth of the silicon core rods within a second preset time period; determining whether to control the air intake by a local control method or by an overall control method based on whether the abnormal growth area with non-overlapping areas and the abnormal growth area after spatial splicing cover a circle of the silicon core rods, and a comparison result of the overall growth rate of the silicon core rods with a preset overall growth rate; the present invention improves the accuracy of the control of the air intake device by improving the accuracy of the analysis of the growth characteristics of the silicon core rods.

Description

Technical Field

[0001] The present invention relates to the technical field of polysilicon deposition used as a main raw material in semiconductor or solar energy industries, and in particular to a polysilicon deposition air intake device and a control method based on the growth characteristics of a silicon core rod. Background Art

[0002] Polycrystalline silicon (also known as polysilicon), used as the main raw material in the semiconductor or solar energy industries, is prepared by a variety of methods, including the Siemens process, the fluidized bed process, VLD (vapor-liquid deposition), and methods for directly refining metallic-grade silicon. The most widely used method is the Siemens process, which involves thermally decomposing a mixed raw gas of chlorosilane or monosilane and hydrogen, and depositing the resultant gas on a silicon core rod to produce polycrystalline silicon. During the polysilicon production process, the growth quality of the silicon core rod has a crucial impact on the performance and quality of the final product. Polysilicon deposition is a complex physical and chemical process, and the performance and control method of the air intake device directly affect the temperature distribution on the surface of the silicon core rod and the growth of the silicon core rod. Traditional air intake device control methods are often crude and cannot be accurately adjusted in real time according to the growth characteristics of the silicon core rod.

[0003] For example, Chinese patent application publication number: CN115132579A discloses a method for controlling the uniformity of a polysilicon layer in a furnace, which includes the following steps: placing multiple substrates in a polysilicon deposition furnace, and at least distributing them at the furnace mouth and furnace tail in the furnace; adjusting the conditions in the polysilicon deposition furnace to polysilicon deposition conditions, and introducing a gaseous polysilicon precursor into the polysilicon deposition furnace from both ends of the furnace mouth and furnace tail to react and deposit, forming a polysilicon layer on the surface including the P+ channel and the connection area; measuring the thickness of the polysilicon layer formed at least at the furnace mouth and furnace tail and obtaining the furnace uniformity value, when the furnace uniformity value of the polysilicon layer thickness is greater than a predetermined value T, heating the furnace tail or cooling the furnace mouth; the control method of this application can significantly improve the performance stability of the polysilicon field plate during mass production, thereby improving its yield, productivity and reducing its cost.

[0004] However, the existing technology has the problem that the analysis of polysilicon growth parameters is not accurate enough, which leads to the inability to accurately control the gas entry and causes uneven growth of the silicon core rod after deposition. Summary of the Invention

[0005] To this end, the present invention provides a polysilicon deposition gas intake device and control method based on the growth characteristics of silicon core rods, so as to overcome the problem in the prior art that the analysis of polysilicon growth parameters is not accurate enough, resulting in the inability to accurately control gas entry and causing uneven growth of silicon core rods after deposition.

[0006] To achieve the above objectives, the present invention provides a method for controlling a polysilicon deposition gas inlet device based on silicon core rod growth characteristics, comprising:

[0007] Acquire surface temperature data of the silicon core rod, growth data of the silicon core rod, and air intake data of the air intake device during the deposition process;

[0008] Determining to obtain abnormal growth area data of the silicon core rod and overall growth rate data of the silicon core rod based on the uniformity of surface temperature distribution of the silicon core rod within the first preset time period and / or the uniformity of growth of the silicon core rod within the second preset time period;

[0009] determining whether to spatially splice the abnormal growth areas based on whether there are non-overlapping areas in the abnormal growth areas;

[0010] Determining whether to control the air intake by a local control method or an overall control method based on a comparison result of the growth abnormality region with non-overlapping regions and the coverage of the growth abnormality region after spatial splicing, and the overall growth rate of the silicon core rod and a preset overall growth rate;

[0011] Based on whether there are conflicting abnormal characteristics in the local growth abnormal area, it is determined to adjust the intake flow or intake angle of the intake device corresponding to the local growth abnormal area, or based on the consistency of the abnormal characteristics of the overall growth area, it is determined to adjust the distribution position or distribution spacing of the overall intake device.

[0012] Furthermore, determining to obtain data of abnormal growth areas of the silicon core rod or obtaining data of the overall growth rate of the silicon core rod includes:

[0013] If the surface temperature distribution uniformity of the silicon core rod within the first preset time period is greater than or equal to the preset distribution uniformity or the growth uniformity of the silicon core rod within the second preset time period is greater than or equal to the preset growth uniformity, determining to obtain the abnormal growth area data of the silicon core rod;

[0014] If the surface temperature distribution uniformity of the silicon core rod within the first preset time period is less than the preset distribution uniformity and the growth uniformity of the silicon core rod within the second preset time period is less than the preset growth uniformity, it is determined to obtain the overall growth rate data of the silicon core rod.

[0015] Furthermore, calculating the uniformity of the surface temperature distribution of the silicon core rod within the first preset time period includes:

[0016] Select several sections at equal intervals along the axial direction of the silicon core rod, and select multiple points at equal angles in the circumferential direction on each section as temperature monitoring points;

[0017] Acquire the temperature data of each monitoring point collected in real time within a first preset time period, and record the temperature value of each point at each moment to form a time series temperature data set;

[0018] Calculating the average temperature of the silicon core rod surface within a first preset time period, and calculating the deviation between the temperature value of each monitoring point and the average temperature;

[0019] The standard deviation of the temperature deviations of all monitoring points is calculated to obtain the uniformity of the surface temperature distribution of the silicon core rod within the first preset time period.

[0020] Furthermore, calculating the growth uniformity of the silicon core rods within the second preset time period includes:

[0021] Select several sections at equal intervals along the axial direction of the silicon core rod, and select multiple points at equal angles in the circumferential direction on each section as growth uniformity monitoring points;

[0022] Regularly measuring the growth parameters of the silicon core rod at each monitoring point within a second preset time period, and recording the growth data of each point at each moment to form a time series of growth data;

[0023] Processing the growth data of all monitoring points within a second preset time period to calculate the diameter change rate of the silicon core rod surface within the time period;

[0024] Calculate the deviation between the diameter change rate of each monitoring point and the average diameter change rate;

[0025] The standard deviation of the diameter change rate deviations of all monitoring points is calculated to obtain the growth uniformity of the silicon core rod within the second preset time period.

[0026] Furthermore, determining whether to spatially stitch the abnormal growth region includes:

[0027] If there are non-overlapping areas in the abnormal growth areas, determining that the abnormal growth areas need to be spatially spliced;

[0028] If there is no non-overlapping area in the abnormal growth area, it is determined that there is no need to spatially splice the abnormal growth area.

[0029] Furthermore, spatially splicing the abnormal growth areas includes:

[0030] Establish a three-dimensional coordinate system with the central axis of the silicon core rod as the coordinate axis;

[0031] Determine the coordinates of the boundary points of each abnormal growth area and its range parameters in the circumferential direction and the axial direction by measurement or calculation;

[0032] According to the boundary point coordinates and range parameters of each abnormal growth area, boundary matching is performed to identify the connection relationship between adjacent abnormal growth areas;

[0033] Based on the coordinates of the boundary points and the connection relationship of each abnormal growth region, the abnormal growth regions are spatially spliced ​​to form a continuous region.

[0034] Further, determining whether to control the intake air using the local control method or the overall control method includes:

[0035] If the abnormal growth area in the non-overlapping area and the abnormal growth area after spatial splicing do not cover the silicon core rod around the entire circle and the overall growth rate of the silicon core rod is greater than or equal to the preset overall growth rate, it is determined to control the air intake by the local control method;

[0036] If any of the growth abnormality areas in the non-overlapping areas and the growth abnormality areas after spatial splicing cover the silicon core rod or the overall growth rate of the silicon core rod is less than the preset overall growth rate, it is determined to control the air intake using the overall control method.

[0037] Furthermore, determining to adjust the intake flow rate or intake angle of the intake device corresponding to the local abnormal growth area includes:

[0038] If the local abnormal growth region has conflicting abnormal features, determining to adjust the intake angle of the intake device corresponding to the local abnormal growth region;

[0039] If the local abnormal growth region does not have conflicting abnormal features, it is determined to adjust the intake flow of the intake device corresponding to the local abnormal growth region.

[0040] Furthermore, determining and adjusting the distribution position or distribution spacing of the integral air intake device includes:

[0041] If the degree of consistency of the abnormal characteristics of the entire growth area is less than or equal to a preset degree of consistency, determining to adjust the distribution position of the entire air intake device;

[0042] If the degree of consistency of the abnormal characteristics of the entire growth area is greater than a preset degree of consistency, it is determined to adjust the distribution spacing of the entire air intake device.

[0043] A polysilicon deposition air inlet device applied to the polysilicon deposition air inlet device control method based on silicon core rod growth characteristics, comprising:

[0044] An air inlet pipe, comprising a closed end located in the deposition furnace, an interface end connected to the silane air inlet, an outer pipe and an inner pipe, wherein the outer pipe is sleeved on the inner pipe, the inner pipe is used to circulate silane gas, and a sealed cavity is formed between the outer pipe and the inner pipe for heat insulation;

[0045] Exhaust holes are evenly spaced along the extension direction of the air inlet pipe, with the opening direction inclined downward at 30°-60° to the axis of the silicon core rod, for uniform gas distribution;

[0046] A connecting piece is located at the interface end and is used to connect the air inlet pipe to the silane air inlet.

[0047] Compared with the prior art, the beneficial effect of the present invention lies in that the present invention can accurately judge the current growth status of the silicon core rod by comparing the uniformity of the surface temperature distribution of the silicon core rod within the first preset time and the uniformity of the growth of the silicon core rod within the second preset time with the corresponding preset values. When the conditions of "the temperature distribution uniformity is greater than or equal to the preset distribution uniformity, or the growth uniformity is greater than or equal to the preset growth uniformity" are met, the data of the abnormal growth area is determined to be obtained, which can quickly lock the local abnormal growth area and conduct targeted analysis and processing of local problems in time; when "the temperature distribution uniformity is less than the preset distribution uniformity and the growth uniformity is less than the preset growth uniformity", the overall growth rate data is determined to be obtained, which helps to grasp the overall growth trend of the silicon core rod from a macro perspective, discover problems in the overall growth process, and avoid ignoring overall growth abnormalities due to local misjudgment. The above method improves the accuracy of the analysis of polysilicon growth parameters and thus realizes precise control of gas entry to obtain silicon core rods with uniform growth.

[0048] Furthermore, by establishing a three-dimensional coordinate system with the central axis of the silicon core rod as the coordinate axis, the present invention can accurately determine the spatial coordinate position of each growth anomaly region on the silicon core rod, including the range in the axial and circumferential directions, and accurately obtain the specific distribution of the growth anomaly region on the silicon core rod. When there are non-overlapping areas, a spatial splicing operation is performed to integrate the scattered growth anomaly regions into a continuous region, avoiding repeated analysis and processing caused by the dispersion of growth anomaly regions, greatly improving the processing efficiency of growth anomaly regions, and reducing manpower and time costs. By determining whether there are non-overlapping areas in the growth anomaly regions, it is decided whether to perform spatial splicing, which helps to rationally allocate production resources. If there are no non-overlapping areas, there is no need to perform a splicing operation, and resources can be concentrated on targeted processing of existing growth anomaly regions. If there are non-overlapping areas that need to be spliced, the overall scale and shape of the growth anomaly region can be more clearly understood after splicing, thereby more scientifically planning and allocating resources. The above method improves the accuracy of polysilicon growth parameter analysis and thus achieves precise control of gas entry to obtain silicon core rods with uniform growth.

[0049] Furthermore, the present invention can accurately judge the type and degree of silicon core rod growth abnormality by comprehensively considering the coverage range of the growth abnormality area and the overall growth rate. When the non-overlapping area and the spliced ​​growth abnormality area do not cover the silicon core rod for a week, and the overall growth rate meets the standard, a local control method is adopted to accurately focus on the local growth abnormality area, avoid unnecessary interference with the normal growth area, and reduce the waste of energy and raw materials; when the growth abnormality area covers a week or the overall growth rate is insufficient, the overall control method is promptly adopted to make adjustments at a macro level to ensure the consistency of the growth environment of the entire silicon core rod, effectively solve the global growth problem, and improve the matching degree between the control strategy and the actual abnormal scenario. This method avoids the "one-size-fits-all" control mode and flexibly selects local or overall control according to actual conditions. When there is a local abnormality and the overall growth is good, the local control only adjusts the air intake for the abnormal growth area, and there is no need to make large-scale changes to the entire air intake system, which reduces equipment adjustment time and energy consumption and improves production efficiency. In the case of overall abnormality, the overall control can quickly adjust the global air intake conditions to restore the growth of silicon core rods to normal as soon as possible, shorten the abnormality processing time, and avoid the spread of abnormalities due to untimely local control, thereby improving resource utilization efficiency and reducing production costs. The above method improves the accuracy of the analysis of polysilicon growth parameters and thus realizes precise control of gas entry to obtain silicon core rods with uniform growth.

[0050] Furthermore, the present invention provides an accurate decision-making basis for adjusting the air intake device by clearly distinguishing whether there are conflicting abnormal characteristics in the local growth abnormality area. When there are conflicting abnormal characteristics, adjusting the air intake angle can target the contradictory growth conditions in the area and focus on improving the abnormal characteristics that are at a disadvantage, such as increasing the concentration of reaction gas in the area where the growth is too slow, increasing heat transfer in the area where the temperature is too low, etc., to achieve targeted regulation of complex abnormal conditions; when there are no conflicting abnormal characteristics, adjusting the air intake flow rate based on the comparison between the overall growth rate and the non-growth abnormal area can effectively solve the problem of overall growth being too slow or too fast. For local areas without conflicting abnormal characteristics, the air intake flow adjustment amount is accurately calculated according to the growth rate difference, avoiding excessive or insufficient gas supply. While ensuring the growth quality of the silicon core rod, unnecessary consumption of reaction gas is reduced, and production costs are reduced; for areas with conflicting abnormal characteristics, adjusting the air intake angle can more reasonably distribute the gas flow direction. The above method improves the accuracy of the analysis of polysilicon growth parameters and thus achieves precise regulation of gas entry to obtain silicon core rods with uniform growth.

[0051] Furthermore, the present invention can more accurately deal with problems arising during the overall growth of the silicon core rod by selecting a method for adjusting the air intake device based on the degree of consistency of the abnormal characteristics of the overall growth area. When the degree of consistency of the abnormal characteristics is low, the distribution position is adjusted to accurately guide the gas to the area with poor growth; when the degree of consistency is high, the distribution spacing is adjusted to optimize the gas distribution as a whole, so that the reaction gas can more effectively participate in the deposition process of the silicon core rod, reduce the uneven growth, thereby increasing the growth rate of the silicon core rod, improving production efficiency, reducing the differences in growth rate, temperature and gas flow in different parts of the silicon core rod, improving the overall growth uniformity of the silicon core rod, reducing internal stress and defects caused by uneven growth, and thus improving the quality and performance of the silicon core rod. BRIEF DESCRIPTION OF THE DRAWINGS

[0052] Figure 1 This is a flowchart of a method for controlling a polysilicon deposition gas inlet device based on silicon core rod growth characteristics according to an embodiment of the present invention;

[0053] Figure 2 This is a flowchart of a process for determining the uniformity of the surface temperature distribution of a silicon core rod in a method for controlling a polysilicon deposition gas inlet device based on the growth characteristics of the silicon core rod according to an embodiment of the present invention;

[0054] Figure 3 This is a flowchart of a method for controlling a polysilicon deposition gas inlet device based on silicon core rod growth characteristics according to an embodiment of the present invention for determining whether to spatially splice the abnormal growth area.

[0055] Figure 4 Schematic diagram of the structure of a polysilicon deposition gas inlet device control method based on silicon core rod growth characteristics according to an embodiment of the present invention in which a silicon core rod has an abnormal growth area;

[0056] Figure 5 Schematic diagram of the structure of a polysilicon deposition air inlet device applied to a polysilicon deposition air inlet device control method based on silicon core rod growth characteristics according to an embodiment of the present invention;

[0057] In the figure, 1, closed end; 2, exhaust hole; 3, interface end; 4, connector; 5, outer tube; 6, inner tube; 7, first abnormal growth area; 8, second abnormal growth area; 9, central axis of silicon core rod. DETAILED DESCRIPTION

[0058] In order to make the objects and advantages of the present invention more clearly understood, the present invention is further described below in conjunction with embodiments; it should be understood that the specific embodiments described herein are merely used to explain the present invention and are not intended to limit the present invention.

[0059] The preferred embodiments of the present invention are described below with reference to the accompanying drawings. It should be understood by those skilled in the art that these embodiments are only used to explain the technical principles of the present invention and are not intended to limit the scope of protection of the present invention.

[0060] It should be noted that, in the description of the present invention, terms such as "up", "down", "left", "right", "inside", and "outside" indicating directions or positional relationships are based on the directions or positional relationships shown in the accompanying drawings. This is only for the convenience of description and does not indicate or imply that the device or element must have a specific orientation, be constructed and operated in a specific orientation. Therefore, it cannot be understood as a limitation on the present invention.

[0061] Furthermore, it should be noted that, in the description of the present invention, unless otherwise expressly specified or limited, the terms "mounted," "connected," and "connected" should be understood in a broad sense. For example, they may refer to fixed connections, detachable connections, or integral connections; mechanical connections or electrical connections; direct connections or indirect connections through an intermediate medium; and internal communication 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.

[0062] See also Figures 1-4 As shown, Figure 1 This is a flowchart of a method for controlling a polysilicon deposition gas inlet device based on silicon core rod growth characteristics according to an embodiment of the present invention; Figure 2 This is a flowchart of a process for determining the uniformity of the surface temperature distribution of a silicon core rod in a method for controlling a polysilicon deposition gas inlet device based on the growth characteristics of the silicon core rod according to an embodiment of the present invention; Figure 3 This is a flowchart of a method for controlling a polysilicon deposition gas inlet device based on silicon core rod growth characteristics according to an embodiment of the present invention for determining whether to spatially splice the abnormal growth area. Figure 4 This is a structural schematic diagram of a polysilicon deposition air inlet device control method based on silicon core rod growth characteristics according to an embodiment of the present invention in which a silicon core rod has an abnormal growth area.

[0063] The embodiment of the present invention provides a method for controlling a polysilicon deposition gas inlet device based on silicon core rod growth characteristics, including:

[0064] Step S1, acquiring surface temperature data of the silicon core rod, growth data of the silicon core rod, and air intake data of the air intake device during the deposition process;

[0065] Step S2, determining and acquiring abnormal growth area data of the silicon core rod and overall growth rate data of the silicon core rod based on the uniformity of surface temperature distribution of the silicon core rod within the first preset time period and / or the uniformity of growth of the silicon core rod within the second preset time period;

[0066] Step S3, determining whether to spatially splice the abnormal growth areas based on whether there are non-overlapping areas in the abnormal growth areas;

[0067] Step S4, determining whether to control the air intake by a local control method or a global control method based on the coverage of the abnormal growth area with non-overlapping areas and the abnormal growth area after spatial splicing, and the comparison result of the overall growth rate of the silicon core rod and the preset overall growth rate;

[0068] Step S5, based on whether there are conflicting abnormal features in the local growth abnormal area, determine whether to adjust the intake flow or intake angle of the intake device corresponding to the local growth abnormal area, or based on the consistency of the abnormal features of the overall growth area, determine whether to adjust the distribution position or distribution spacing of the overall intake device.

[0069] The growth data of the silicon core rod in the embodiment of the present invention includes but is not limited to "diameter change rate data, growth rate data and abnormal growth area data", and the air intake data of the air intake device includes but is not limited to "gas flow data, gas temperature data and air intake device distribution position data". The abnormal growth area is the area with uneven surface temperature distribution of the silicon core rod and the area with uneven growth of the silicon core rod.

[0070] In the embodiment of the present invention, the initial distribution position of the air inlet device can determine the axial and radial distribution positions of the air inlet device according to the length, diameter and target growth shape (such as cylindrical or conical) of the silicon core rod. For example, according to the symmetry of the deposition furnace, a uniform angle distribution is adopted (such as arranging an air inlet device every 60°); the initial distribution angle of the air inlet device can be determined by calculating or simulating the diffusion angle of silane gas (such as chlorosilane) to determine the inclination angle of the air inlet device (such as 30°-60°) so that the gas can cover the target growth area. The angle needs to avoid direct vertical impact on the surface of the silicon core rod to prevent local turbulence from causing uneven growth. The initial value can be set based on the angle with the best gas distribution uniformity in historical deposition experiments; the air inlet device The initial air intake flow rate can be calculated based on the reduction and deposition efficiency of chlorosilane to determine the required gas flow rate per unit time (e.g., 10-20 L / min). This can be correlated with the preset overall growth rate of the silicon core rod (e.g., 0.5 mm / h). The required air intake velocity can be inferred through a gas-growth rate model (e.g., the Arrhenius equation). The initial distribution spacing of the air intake devices can be calculated by calculating the gas diffusion radius (e.g., CFD simulation) to ensure that the air flow fields of adjacent air intake devices partially overlap (with an overlap rate of approximately 20%-30%) to avoid dead corners. Based on previous experimental data, the spacing that minimizes the standard deviation of the temperature field and growth rate is selected (e.g., an axial spacing of 15-30 cm, with the circumferential spacing adjusted according to the number of air intake devices).

[0071] Specifically, in step S2, when determining to obtain data on the abnormal growth region of the silicon core rod or to obtain data on the overall growth rate of the silicon core rod, determining whether to obtain data on the abnormal growth region of the silicon core rod or to obtain data on the overall growth rate of the silicon core rod is based on the uniformity of the surface temperature distribution of the silicon core rod within the first preset time period and / or the uniformity of the growth of the silicon core rod within the second preset time period;

[0072] When the surface temperature distribution uniformity of the silicon core rod within the first preset time period is greater than or equal to the preset distribution uniformity or the growth uniformity of the silicon core rod within the second preset time period is greater than or equal to the preset growth uniformity, determining to obtain the abnormal growth area data of the silicon core rod;

[0073] When the surface temperature distribution uniformity of the silicon core rod within the first preset time period is less than the preset distribution uniformity and the growth uniformity of the silicon core rod within the second preset time period is less than the preset growth uniformity, it is determined to obtain the overall growth rate data of the silicon core rod.

[0074] In an embodiment of the present invention, the first preset duration can be determined by collecting a large amount of historical data from past polysilicon deposition production processes, including data on the uniformity of silicon core rod surface temperature distribution and corresponding monitoring durations in different production batches, analyzing the monitoring duration corresponding to the temperature uniformity reaching a stable state when qualified products are produced (i.e., subsequent testing does not find growth abnormalities caused by temperature distribution problems), calculating the central trend (such as the average value) of these duration data, and combining production experience and actual needs to determine the first preset duration. For example, a large polysilicon production company collected production data from the past 1,000 batches. The surface temperature uniformity of the silicon core rods in each production batch was analyzed to find the monitoring duration in each batch when the temperature uniformity reached a stable state and no growth abnormalities were caused by temperature problems. After statistics, the average value of these duration data is 55 minutes. Taking into account the stability of the equipment and product quality requirements in actual production, in order to ensure that the uniformity of the surface temperature distribution of the silicon core rod can be accurately judged, the first preset duration is determined to be 55 minutes. In subsequent production, if the equipment is upgraded or the process parameters change significantly, the first preset duration will be re-evaluated and adjusted based on the new historical data; the second preset duration can be determined according to the growth stage of the silicon core rod. For example, in the early growth stage of the silicon core rod (0 to 20 hours), the value is 2 hours; in the middle growth stage (20 to 65 hours), the value is 4 hours; in the late growth stage (6 5 to 85 hours), with a value of 6 hours. The preset distribution uniformity is the average value of the surface temperature distribution uniformity of the silicon core rods when no abnormal growth area appears in the silicon core rods under the same deposition conditions within several first preset time periods. The preset growth uniformity is the average value of the growth uniformity of the silicon core rods when no abnormal growth area appears in the silicon core rods under the same deposition conditions within several second preset time periods. The same deposition conditions include but are not limited to "the same growth stage of the silicon core rods, the same growth data of the silicon core rods, and the same air intake data of the silicon core rods", but the above values ​​are not limited thereto. Those skilled in the art may also adjust the values ​​according to actual needs.

[0075] The present invention can accurately judge the current growth status of the silicon core rod by comparing the uniformity of the surface temperature distribution of the silicon core rod within a first preset time period with the uniformity of the growth of the silicon core rod within a second preset time period with the corresponding preset values. When the conditions of "the uniformity of the temperature distribution is greater than or equal to the preset distribution uniformity, or the uniformity of the growth is greater than or equal to the preset growth uniformity" are met, the data of the abnormal growth area is determined to be obtained, which can quickly lock the local abnormal growth area and conduct targeted analysis and processing of local problems in time; when "the uniformity of the temperature distribution is less than the preset distribution uniformity and the uniformity of the growth is less than the preset growth uniformity", the overall growth rate data is determined to be obtained, which helps to grasp the overall growth situation of the silicon core rod from a macro perspective, discover problems in the overall growth process, and avoid ignoring overall growth abnormalities due to local misjudgment. The above method improves the accuracy of the analysis of polysilicon growth parameters and thus realizes precise control of gas entry to obtain silicon core rods with uniform growth.

[0076] Specifically, in step S2, the step of determining the uniformity of the surface temperature distribution of the silicon core rod within the first preset time period includes:

[0077] Step S2101: selecting a plurality of cross sections at equal intervals along the axial direction of the silicon core rod, and selecting a plurality of points at equal angles in the circumferential direction on each cross section as temperature monitoring points;

[0078] Step S2102: acquiring the temperature data of each monitoring point collected in real time within a first preset time period, and recording the temperature value of each point at each moment to form a time series temperature data set;

[0079] Step S2103, calculating the average temperature of the silicon core rod surface within the first preset time period, and calculating the deviation between the temperature value of each monitoring point and the average temperature;

[0080] Step S2104 , calculating the standard deviation of the temperature deviations of all monitoring points to obtain the uniformity of the surface temperature distribution of the silicon core rod within a first preset time period.

[0081] The present invention can perform non-contact temperature measurement on the surface of the silicon core rod by using an infrared thermometer. The temperature is measured by measuring the intensity of infrared radiation emitted from the surface of the silicon core rod. For example, a suitable infrared thermometer is selected based on the temperature range that the silicon core rod may reach during the production process. For example, the ST300 colorimetric infrared thermometer is suitable for high-temperature measurement in polysilicon production. Its temperature measurement range can cover the temperature range during the growth process of the silicon core rod. A high-precision infrared thermometer is selected, such as the MLX90640 infrared array sensor, which has a frame accuracy of ±1°C. In complex environments such as reduction furnaces, an infrared thermometer that is insensitive to window contamination, signal attenuation, etc. should be selected. For example, the ST300 colorimetric thermometer is basically not affected by the emissivity of the material and signal attenuation, and is also insensitive to slight window contamination.

[0082] In the embodiment of the present invention, if the length of the silicon core rod is 1 meter and the first preset time is 60 minutes, temperature monitoring points are selected at five sections (0.2 m, 0.4 m, 0.6 m, 0.8 m, and 1.0 m) at equal intervals along the axial direction of the silicon core rod. Six points are selected at equal angles in the circumferential direction on each section (one monitoring point is selected every 60 degrees). Six temperature monitoring points are evenly arranged on each of the five sections of the silicon core rod, for a total of 30 monitoring points. During the first preset time (60 minutes), temperature data from each monitoring point is collected in real time, and the temperature data is recorded once per minute to form a time series temperature data set. For example, the temperature data of the first monitoring point within 60 minutes is: T 1,1 ,T 1,2 ,…,T 1,60 For each monitoring point, calculate its average temperature within 60 minutes, then calculate the average temperature of all monitoring points, for each monitoring point, calculate the deviation between its average temperature and the overall average temperature, and calculate the standard deviation of the temperature deviation of all monitoring points to obtain the uniformity of the surface temperature distribution of the silicon core rod within the first preset time length.

[0083] Specifically, in step S2, the step of determining the growth uniformity of the silicon core rods within the second preset time period includes:

[0084] Step S2201: selecting a plurality of cross sections at equal intervals along the axial direction of the silicon core rod, and selecting a plurality of points at equal angles in the circumferential direction on each cross section as growth uniformity monitoring points;

[0085] Step S2202, regularly measuring the growth parameters of the silicon core rod at each monitoring point within a second preset time period, and recording the growth data of each point at each moment to form a time series of growth data;

[0086] Step S2203, processing the growth data of all monitoring points within the second preset time period, and calculating the diameter change rate of the silicon core rod surface within the time period;

[0087] Step S2204, calculating the deviation between the diameter change rate of each monitoring point and the average diameter change rate;

[0088] Step S2205 , calculating the standard deviation of the diameter change rate deviations of all monitoring points to obtain the growth uniformity of the silicon core rod within the second preset time period.

[0089] The present invention can capture images of silicon core rods using a high-speed camera, and then use image processing technology to analyze the silicon core rod contours in the image to calculate their diameter change rate. For example, a high-temperature resistant camera and lens can be selected, or a heat-insulating protective device can be used to protect an ordinary camera. For example, an industrial camera with a heat shield can be used, or a high-temperature resistant optical glass lens can be used. A high-resolution black and white camera can be selected because black and white cameras are more sensitive to infrared light in high-temperature environments and can better capture the contours of the silicon core rods. In high-temperature environments, images may be affected by thermal radiation and thermal disturbances, resulting in image quality degradation. An automatic color equalization (ACE) algorithm can be used to pre-process the image to enhance image contrast and suppress background light and thermal haze. Image inverse filtering technology can be used to eliminate the impact of thermal disturbances on the image. Image quality can be improved through frequency domain inverse filtering recovery technology. The collected image is processed using image processing software (such as OpenCV) to extract the contour information of the silicon core rod. An edge detection algorithm (such as the Canny algorithm) can be used to identify the edges of the silicon core rods and calculate the diameter change rate of the silicon core rods. By analyzing image data at multiple time points, the diameter change rate of each monitoring point is calculated.

[0090] In the embodiment of the present invention, if the length of the silicon core rod is 1 meter and the second preset time is 2 hours, 5 cross-sections (0.2 meter, 0.4 meter, 0.6 meter, 0.8 meter, and 1.0 meter) are selected at equal intervals along the axial direction of the silicon core rod, and 6 points are selected at equal angles in the circumferential direction on each cross-section (one monitoring point is selected every 60 degrees). On each of the 5 cross-sections of the silicon core rod, 6 growth uniformity monitoring points are evenly arranged, for a total of 30 monitoring points. Within the second preset time, the growth parameters of the silicon core rod at each monitoring point are regularly measured (for example, once every 30 minutes), and the growth data of each point at each moment is recorded to form a time series of growth data. For example, the growth data of the first monitoring point within 2 hours is: D 1,1 ,D 1,2 ,…,D 1,4 For each monitoring point, calculate its diameter change rate within the second preset time length, then calculate the average diameter change rate of all monitoring points, for each monitoring point, calculate the deviation between its diameter change rate and the average diameter change rate, and calculate the standard deviation of the diameter change rate deviation of all monitoring points to obtain the growth uniformity of the silicon core rod within the second preset time length.

[0091] Specifically, in step S3, when determining whether to spatially splice the abnormal growth regions, determining whether to spatially splice the abnormal growth regions is based on whether there are non-overlapping regions in the abnormal growth regions;

[0092] When there are non-overlapping areas in the abnormal growth areas, determining that the abnormal growth areas need to be spatially spliced;

[0093] When there is no non-overlapping area in the abnormal growth area, it is determined that there is no need to spatially splice the abnormal growth area.

[0094] In the embodiment of the present invention, determining whether there are non-overlapping areas in the abnormal growth areas includes establishing a three-dimensional coordinate system with the central axis 9 of the silicon core rod as the coordinate axis, determining the spatial coordinate position of each abnormal growth area on the silicon core rod, including the coordinates of the starting point and the end point, and for each abnormal growth area, determining its range in the circumferential direction and the axial direction. For example, the first abnormal growth area 7 may be between 0.2 meters and 0.4 meters in the axial direction and from 0 degrees to 120 degrees in the circumferential direction; the second abnormal growth area 8 may be between 0.4 meters and 0.6 meters in the axial direction and from 120 degrees to 240 degrees in the circumferential direction. The coordinate ranges of different abnormal growth areas are compared to determine whether there are overlapping areas. If the two abnormal growth areas have overlapping parts in the circumferential direction or the axial direction, it is considered that there are overlapping areas. If the two abnormal growth areas have no overlapping parts in both the circumferential direction and the axial direction, it is considered that there are non-overlapping areas.

[0095] It is understandable that the silicon core rod used in the method of the present invention may have different numbers of abnormal growth areas during the actual deposition process. Here, only two abnormal growth areas are used as an example to describe the method of judging whether there are non-overlapping areas among the abnormal growth areas in the embodiment of the present invention, which does not mean that only two abnormal growth areas appear in the silicon core rod during the actual deposition process.

[0096] By establishing a three-dimensional coordinate system with the central axis 9 of the silicon core rod as the coordinate axis, the present invention can accurately determine the spatial coordinate position of each growth anomaly region on the silicon core rod, including the range in the axial and circumferential directions, and accurately obtain the specific distribution of the growth anomaly region on the silicon core rod. When there are non-overlapping areas, a spatial splicing operation is performed to integrate the scattered growth anomaly regions into a continuous region, avoiding repeated analysis and processing caused by the dispersion of growth anomaly regions, greatly improving the processing efficiency of the growth anomaly regions, and reducing manpower and time costs. By determining whether there are non-overlapping areas in the growth anomaly regions, it is determined whether to perform spatial splicing, which helps to rationally allocate production resources. If there are no non-overlapping areas, there is no need to perform a splicing operation, and resources can be concentrated on targeted processing of existing growth anomaly regions. If there are non-overlapping areas that need to be spliced, the overall scale and shape of the growth anomaly region can be more clearly understood after splicing, thereby more scientifically planning and allocating resources. The above method improves the accuracy of the analysis of polysilicon growth parameters and thus achieves precise control of gas entry to obtain silicon core rods with uniform growth.

[0097] Specifically, in step S3, the step of spatially splicing the abnormal growth areas includes:

[0098] Step S3301, establishing a three-dimensional coordinate system with the silicon core rod central axis 9 as the coordinate axis;

[0099] Step S3302, determining the coordinates of the boundary points of each abnormal growth region and its range parameters in the circumferential direction and the axial direction by measurement or calculation;

[0100] Step S3303, performing boundary matching based on the boundary point coordinates and range parameters of each abnormal growth region to identify the connection relationship between adjacent abnormal growth regions;

[0101] Step S3304: Based on the coordinates of the boundary points and the connection relationship of each abnormal growth region, the abnormal growth regions are spatially spliced ​​to form a continuous region.

[0102] In the embodiment of the present invention, the central axis 9 of the silicon core rod is the Z axis, the center of the bottom surface of the silicon core rod is the origin O, the two directions perpendicular to each other in the horizontal direction are the X axis and the Y axis respectively, and the unit length is set to 1 mm. The abnormal growth area A: axial range: Z coordinate is from 100 mm to 150 mm, circumferential range: starting from the positive direction of the X axis, rotated 30° to 90° clockwise, boundary point coordinates: at Z=100 mm, the point coordinates corresponding to 30° in the circumferential direction are (86.6, 50, 100), and the point coordinates corresponding to 90° are (0, 100, 100); at Z=150 mm, the corresponding boundary point coordinates are (86.6, 50, 150) and (0, 100, 150);

[0103] Abnormal growth region B: Axial range: Z coordinate from 140 mm to 190 mm, circumferential range: starting from the positive direction of the X axis, rotating clockwise from 80° to 140°, boundary point coordinates: at Z = 140 mm, the point coordinates corresponding to 80° in the circumferential direction are (17.4, 98.5, 140), and the point coordinates corresponding to 140° are (-76.6, 64.3, 140); at Z = 190 mm, the corresponding boundary point coordinates are (17.4, 98.5, 190) and (-76.6, 64.3, 190);

[0104] Abnormal growth region C: Axial range: Z coordinate from 180mm to 230mm, circumferential range: starting from the positive direction of the X-axis, rotating clockwise from 130° to 190°, boundary point coordinates: at Z=180mm, the point coordinates corresponding to 130° in the circumferential direction are (-64.3, 76.6, 180), and the point coordinates corresponding to 190° are (-98.5, -17.4, 180); at Z=230mm, the corresponding boundary point coordinates are (-64.3, 76.6, 230) and (-98.5, -17.4, 230);

[0105] The connection relationship between abnormal growth region A and abnormal growth region B: The axial end point Z = 150 mm of abnormal growth region A overlaps with the axial starting point Z = 140 mm of abnormal growth region B (140 mm to 150 mm). The circumferential range of abnormal growth region A is 30° to 90°, and the circumferential range of abnormal growth region B is 80° to 140°. The two overlap at 80° to 90°. It can be determined that abnormal growth region A and abnormal growth region B overlap in the axial direction and partially overlap in the circumferential direction, and are in an adjacent connection relationship.

[0106] The connection relationship between abnormal growth region B and abnormal growth region C: The axial end point Z = 190 mm of abnormal growth region B overlaps with the axial starting point Z = 180 mm of abnormal growth region C (180 mm to 190 mm). The circumferential range of abnormal growth region B is 80° to 140°, and the circumferential range of abnormal growth region C is 130° to 190°. The two overlap at 130° to 140°. It can be determined that abnormal growth region B and abnormal growth region C overlap in the axial direction and partially overlap in the circumferential direction, and are in an adjacent connection relationship.

[0107] The connection relationship between the abnormal growth area A and the abnormal growth area C: the axial end point Z=150mm of the abnormal growth area A does not overlap with the axial starting point Z=180mm of the abnormal growth area C. The circumferential range of the abnormal growth area A is 30° to 90°, and the circumferential range of the abnormal growth area C is 130° to 190°. There is no overlap between the two. It can be determined that there is no adjacent connection relationship between the abnormal growth area A and the abnormal growth area C. The axial range of the three areas is integrated from 100mm to 230mm. The circumferential range integration: the circumferential range of the three areas is integrated from 30° to 190°. The continuous area after splicing: axial range: Z coordinate from 100mm to 230mm, circumferential range: starting from the positive direction of the X-axis, rotated clockwise from 30° to 190°. This continuous area contains all parts of the abnormal growth area A, abnormal growth area B and abnormal growth area C, and is spliced ​​together through boundary matching and connection relationship identification.

[0108] Specifically, in step S4, when determining whether to control the air intake by the local control method or the overall control method, the determination of whether to control the air intake by the local control method or the overall control method is made based on the coverage of the abnormal growth area with non-overlapping areas and the abnormal growth area after spatial splicing, and the comparison result of the overall growth rate of the silicon core rod and the preset overall growth rate;

[0109] When the abnormal growth area with non-overlapping areas and the abnormal growth area after spatial splicing do not cover a circle of the silicon core rod and the overall growth rate of the silicon core rod is greater than or equal to the preset overall growth rate, determining to control the air intake by the local control method;

[0110] When either the abnormal growth area in the non-overlapping area or the abnormal growth area after spatial splicing covers the silicon core rod or the overall growth rate of the silicon core rod is less than the preset overall growth rate, it is determined to control the air intake by the overall control method.

[0111] The preset overall growth rate in the embodiment of the present invention is the average value of the overall growth rate of the silicon core rod under the same deposition conditions for several times. The abnormal growth area determined to have non-overlapping areas and the abnormal growth area after spatial splicing do not cover a circle of the silicon core rod, including the abnormal growth area, which does not reach 360 degrees in the circumferential direction. However, the above value is not limited to this, and those skilled in the art can also adjust the value according to actual needs.

[0112] The present invention can accurately judge the type and degree of silicon core rod growth abnormality by comprehensively considering the coverage range of the growth abnormality area and the overall growth rate. When the non-overlapping area and the spliced ​​growth abnormality area do not cover the silicon core rod for a week, and the overall growth rate meets the standard, a local control method is adopted to accurately focus on the local growth abnormality area, avoid unnecessary interference with the normal growth area, and reduce the waste of energy and raw materials; when the growth abnormality area covers a week or the overall growth rate is insufficient, the overall control method is promptly adopted to make adjustments at a macro level to ensure the consistency of the growth environment of the entire silicon core rod, effectively solve the global growth problem, and improve the matching degree between the control strategy and the actual abnormal scene. This method avoids It eliminates the need for a "one-size-fits-all" control method and flexibly selects local or overall control based on actual conditions. When there is a local abnormality and the overall growth is good, the local control only adjusts the air intake for the abnormal growth area, without the need for large-scale changes to the entire air intake system, reducing equipment adjustment time and energy consumption and improving production efficiency. In the event of an overall abnormality, the overall control can quickly adjust the global air intake conditions to restore the growth of the silicon core rod to normal as soon as possible, shorten the abnormality processing time, and avoid the spread of abnormalities due to untimely local control, thereby improving resource utilization efficiency and reducing production costs. The above method improves the accuracy of the analysis of polysilicon growth parameters and thus realizes precise control of gas entry to obtain silicon core rods with uniform growth.

[0113] Specifically, in step S5, when it is determined that the intake is controlled by the local control method, the intake flow rate or intake angle of the intake device corresponding to the local growth abnormality area is adjusted according to whether the local growth abnormality area has conflicting abnormal characteristics;

[0114] When the local abnormal growth region has conflicting abnormal features, determining to adjust the intake angle of the intake device corresponding to the local abnormal growth region;

[0115] When the local abnormal growth region does not have conflicting abnormal features, it is determined to adjust the intake flow of the intake device corresponding to the local abnormal growth region.

[0116] In the embodiment of the present invention, the determination of whether a local abnormal growth region has conflicting abnormal characteristics includes the occurrence of contradictory growth conditions in the local region, for example, the growth rate of some positions in the same region is greater than the maximum growth rate of the non-growing abnormal region, while the growth rate of other positions is less than the minimum growth rate of the non-growing abnormal region; the temperature of some positions in the same region is greater than the maximum temperature of the non-growing abnormal region, while the temperature of other positions is less than the minimum temperature of the non-growing abnormal region; the gas flow rate of some positions in the same region is less than the minimum gas flow rate of the non-growing abnormal region, while the gas flow rate of other positions is greater than the maximum gas flow rate of the non-growing abnormal region; the said adjustment of the air intake of the air intake device corresponding to the local abnormal growth region The angle includes adjusting the intake angle of the intake device to a direction tending towards the weak abnormal feature, and the weak abnormal feature includes but is not limited to "the growth rate is less than the minimum growth rate of the non-growth abnormal area, the temperature is less than the minimum temperature of the non-growth abnormal area, and the gas flow rate is less than the minimum gas flow rate of the non-growth abnormal area". The adjustment amount of the intake angle can be calculated by establishing a mathematical model and comprehensively considering the above parameters. For example, an adjustment coefficient is set, which is proportional to the degree of difference of the abnormal feature and the size of the growth abnormal area, and inversely proportional to the stability of the abnormal feature. Through experiments or simulations, the specific value of the adjustment coefficient under different circumstances is determined, thereby calculating the adjustment amount of the intake angle.

[0117] In one embodiment of the present invention, during the polysilicon deposition process, a silicon core rod is monitored in real time. The system acquires surface temperature data, growth data, and air intake data from the silicon core rod. A first preset duration is set to 30 minutes, and a second preset duration is set to 60 minutes. Calculations reveal that conflicting anomalies exist within a local region of the silicon core rod, 20-30 cm axially and 60-120 degrees circumferentially. Adjustment of the air intake angle of the corresponding air intake device is required in this region. The maximum growth rate in the non-abnormal growth region is 0.5 mm / h. Within this local abnormal growth region, the growth rate reaches 0.7 mm / h at some locations, while the growth rate at others is only 0.2 mm / h. The growth rate of 0.2 mm / h, which is less than the minimum, is analyzed. The difference between this value and the minimum value of the non-abnormal growth region (assuming the minimum value is 0.3 mm / h) is 0.1 mm / h. The maximum temperature in the non-abnormal growth region is 1050°C, and the minimum is 1000°C. The temperature in this abnormal growth region ranged from 1100°C to 950°C in some locations. The temperature below the minimum of 950°C was analyzed, with the difference between this and the minimum value in the non-anomalous growth region being 50°C. The maximum gas flow rate in the non-anomalous growth region was 15 L / min, while the minimum was 10 L / min. The gas flow rate in this abnormal growth region ranged from 8 L / min to 18 L / min in some locations. The gas flow rate of 8 L / min less than the minimum value is used as the analysis object, and the difference between it and the minimum value of the non-growth abnormal area is 2 L / min; each parameter is assigned a weight, assuming that the growth rate weight is 0.4, the temperature weight is 0.3, and the gas flow weight is 0.3; the difference degree score of the abnormal characteristics is 15.64 through weighted average calculation. The local growth abnormal area has an axial length of 10 cm and a circumferential angle range of 60°. According to certain quantitative standards (for example, quantifying 1 cm in the axial direction as 1 point and quantifying 1° in the circumferential angle as 0.1 point), the calculated growth abnormal area size score is 16. By observing the data in the past 2 hours, it was found that the conflicting abnormal feature has persisted. The stability score is set to 0.2 (the score range is 0-1, the lower the value, the higher the stability and the more serious the problem). The adjustment coefficient calculation formula is set as adjustment coefficient = k× ; Wherein, k is a constant determined by experiment or simulation; the adjustment amount of the intake angle is linearly related to the adjustment coefficient, and each unit adjustment coefficient corresponds to an intake angle adjustment of 0.5°, so the final calculated intake angle adjustment amount is the product of the adjustment coefficient and 0.5.

[0118] In an embodiment of the present invention, adjusting the air flow rate of the air intake device corresponding to the local growth abnormality region includes, when the local growth abnormality region does not have conflicting abnormal characteristics, determining whether the overall growth state of the region is too fast or too slow; if the overall growth rate is less than the average growth rate of the non-growth abnormality region, indicating that the growth is too slow, the air flow rate of the air intake device should be increased to provide more reaction gas for the growth of the silicon core rod to accelerate the growth rate; if the overall growth rate is greater than the average growth rate of the non-growth abnormality region, indicating that the growth is too fast, the air flow rate of the air intake device should be reduced to reduce the supply of reaction gas, thereby slowing down the growth rate; calculating the flow rate adjustment amount based on the difference in growth rate between the local growth abnormality region and the non-growth abnormality region, establishing a mathematical model, for example, setting the flow rate adjustment amount to be linearly related to the growth rate difference, and determining the proportional coefficient through a large number of experiments or simulations, assuming that it is experimentally determined that the corresponding air flow rate is adjusted by 1 L / min for every 0.1 mm / h difference in growth rate, if the average growth rate of the local growth abnormality region is 0.3 mm / h lower than the average growth rate of the non-growth abnormality region, the air flow rate needs to be increased by 3 L / min.

[0119] The present invention provides an accurate decision-making basis for adjusting the air intake device by clearly distinguishing whether there are conflicting abnormal characteristics in the local growth abnormal area. When conflicting abnormal characteristics exist, adjusting the air intake angle can target the contradictory growth conditions in the area and focus on improving the abnormal characteristics that are at a disadvantage, such as increasing the concentration of reaction gas in the area where the growth is too slow, increasing heat transfer in the area where the temperature is too low, etc., to achieve targeted regulation of complex abnormal conditions; when there are no conflicting abnormal characteristics, adjusting the air intake flow rate based on the comparison between the overall growth rate and the non-growth abnormal area can effectively solve the problem of overall growth being too slow or too fast. For local areas without conflicting abnormal characteristics, the air intake flow adjustment amount is accurately calculated according to the growth rate difference, avoiding excessive or insufficient gas supply. While ensuring the growth quality of the silicon core rod, unnecessary consumption of reaction gas is reduced, and production costs are reduced; for areas with conflicting abnormal characteristics, adjusting the air intake angle can more reasonably distribute the gas flow direction. The above method improves the accuracy of the analysis of polysilicon growth parameters and thus achieves accurate regulation of gas entry to obtain silicon core rods with uniform growth.

[0120] Specifically, in step S5, when it is determined that the air intake is controlled by the overall control method, the distribution position or distribution spacing of the overall air intake device is adjusted according to the consistency of the abnormal characteristics of the overall growth area;

[0121] When the degree of consistency of the abnormal characteristics of the overall growth area is less than or equal to a preset degree of consistency, determining to adjust the distribution position of the overall air intake device;

[0122] When the degree of consistency of the abnormal features of the entire growth area is greater than a preset degree of consistency, it is determined to adjust the distribution spacing of the entire air intake device.

[0123] In an embodiment of the present invention, when it is determined that the air intake is controlled by the overall control method, if the overall growth rate of the silicon core rod is less than the preset overall growth rate, the total air intake flow rate is increased. A mathematical model can be established to calculate the increase in the total air intake flow rate based on the difference between the overall growth rate and the preset overall growth rate. For example, the total air intake flow rate adjustment amount is set to be linearly related to the growth rate difference, and the proportional coefficient is determined through a large number of experiments or simulations, and then the total air intake flow rate is increased according to the proportional coefficient.

[0124] The degree of consistency of abnormal characteristics of the overall growth region described in the embodiments of the present invention can be determined according to the following method: the overall growth region is divided into multiple small sub-regions. The division of the sub-regions needs to comprehensively consider factors such as the shape of the silicon core rod and the distribution of the gas inlet device. For example, the silicon core rod can be evenly divided into several small regions along the axial and circumferential directions. Growth rate, temperature, and gas flow rate data are collected for each sub-region. For each abnormal characteristic parameter (growth rate, temperature, gas flow rate), the average characteristic value of the overall growth region is first calculated, and then the deviation of the characteristic value of each sub-region from the average characteristic value is calculated. For example, the growth rate deviation of a sub-region is the growth rate of the sub-region minus the average growth rate of the overall growth region. Based on actual production experience and experimental data, different weights are assigned to each abnormal characteristic parameter. For example, the growth rate has a greater impact on the quality of the silicon core rod and can be assigned a higher weight (e.g., 0.5). The temperature and gas flow rate are assigned weights of 0.3 and 0.2, respectively. The deviations of each abnormal characteristic in each sub-region are multiplied by the corresponding weights and then summed to obtain the comprehensive abnormal characteristic deviation of the sub-region. The standard deviation of the comprehensive abnormal characteristic deviations of all sub-regions is calculated to obtain the degree of consistency of the abnormal characteristics of the overall growth region.

[0125] The preset consistency level in the embodiment of the present invention is the average value of the consistency level of abnormal characteristics of the overall growth area when the gas intake is controlled by the overall control method under the same deposition conditions for several times. The adjustment of the distribution position of the overall gas intake device includes but is not limited to moving the gas intake device to the area with low growth rate, low temperature and insufficient gas flow to enhance the gas supply in these areas. According to the abnormal characteristics of the sub-area, the distribution position of the gas intake device is readjusted to make the gas more evenly distributed on the surface of the silicon core rod. The adjustment of the distribution spacing of the overall gas intake device includes increasing the distance between the gas intake devices if the growth rate and temperature are generally high, and increasing the distance between the gas intake devices if the growth rate and temperature are generally high. The temperature is generally low, and the distance between the air intake devices is reduced. The movement amount of the air intake device can be determined according to the severity of the abnormal characteristics of the sub-area. For example, if the growth rate is more than 10% lower than the average value, the movement distance can be set to 10 cm; if it is 5%-10% lower than the average value, the movement distance can be set to 5 cm. The adjustment amount of the distribution spacing can be determined according to the general level of growth rate and temperature. For example, if the growth rate is more than 10% higher than the average value, the spacing is increased by 5 cm; if it is more than 10% lower than the average value, the spacing is reduced by 5 cm. However, the above values ​​are not limited to this, and those skilled in the art can also adjust the values ​​according to actual needs.

[0126] The present invention can more accurately deal with problems arising during the overall growth of silicon core rods by selecting a method for adjusting the air intake device based on the degree of consistency of the abnormal characteristics of the overall growth area. When the degree of consistency of the abnormal characteristics is low, the distribution position is adjusted to accurately guide the gas to the area with poor growth. When the degree of consistency is high, the distribution spacing is adjusted to optimize the gas distribution as a whole, so that the reaction gas can more effectively participate in the deposition process of the silicon core rod, reduce the uneven growth, thereby increasing the growth rate of the silicon core rod, improving production efficiency, reducing the differences in growth rate, temperature and gas flow in different parts of the silicon core rod, improving the overall growth uniformity of the silicon core rod, reducing the internal stress and defects caused by uneven growth, and thus improving the quality and performance of the silicon core rod.

[0127] See also Figure 5 As shown, Figure 5 Schematic diagram of the structure of a polysilicon deposition air inlet device according to an embodiment of the present invention applied to a polysilicon deposition air inlet device control method based on silicon core rod growth characteristics.

[0128] Specifically, a polysilicon deposition air inlet device applied to the polysilicon deposition air inlet device control method based on silicon core rod growth characteristics includes:

[0129] An air inlet pipe includes a closed end 1 located in the deposition furnace, an interface end 3 connected to the silane air inlet, an outer tube 5, and an inner tube 6. The outer tube 5 is sleeved on the inner tube 6. The inner tube 6 is used to circulate silane gas. A sealed cavity is formed between the outer tube 5 and the inner tube 6 for thermal insulation.

[0130] Exhaust holes 2 are evenly spaced along the extension direction of the air inlet pipe, with the opening direction inclined downward at 30°-60° to the vertical direction (the direction of the silicon core rod axis) to evenly distribute the gas;

[0131] The connecting piece 4 is located at the interface end and is used to connect the air inlet pipe to the silane air inlet.

[0132] Thus far, the technical solutions of the present invention have been described in conjunction with the preferred embodiments shown in the accompanying drawings. However, it will be readily understood by those skilled in the art that the scope of protection of the present invention is obviously not limited to these specific embodiments. Without departing from the principles of the present invention, those skilled in the art may make equivalent changes or substitutions to the relevant technical features, and the technical solutions after such changes or substitutions will fall within the scope of protection of the present invention.

Claims

1. A method for controlling a polysilicon deposition gas inlet device based on silicon core rod growth characteristics, characterized in that: include: Acquire surface temperature data of the silicon core rod, growth data of the silicon core rod, and air intake data of the air intake device during the deposition process; Determining to obtain abnormal growth area data of the silicon core rod and overall growth rate data of the silicon core rod based on the uniformity of surface temperature distribution of the silicon core rod within the first preset time period and / or the uniformity of growth of the silicon core rod within the second preset time period; Calculating the uniformity of the surface temperature distribution of the silicon core rod within the first preset time period includes: Select several sections at equal intervals along the axial direction of the silicon core rod, and select multiple points at equal angles in the circumferential direction on each section as temperature monitoring points; Acquire the temperature data of each monitoring point collected in real time within a first preset time period, and record the temperature value of each point at each moment to form a time series temperature data set; Calculating the average temperature of the silicon core rod surface within a first preset time period, and calculating the deviation between the temperature value of each monitoring point and the average temperature; Calculate the standard deviation of the temperature deviations of all monitoring points to obtain the uniformity of the surface temperature distribution of the silicon core rod within the first preset time period; Calculating the growth uniformity of the silicon core rod within the second preset time period includes: Select several sections at equal intervals along the axial direction of the silicon core rod, and select multiple points at equal angles in the circumferential direction on each section as growth uniformity monitoring points; Regularly measuring the growth parameters of the silicon core rod at each monitoring point within a second preset time period, and recording the growth data of each point at each moment to form a time series of growth data; Processing the growth data of all monitoring points within a second preset time period to calculate the diameter change rate of the silicon core rod surface within the time period; Calculate the deviation between the diameter change rate of each monitoring point and the average diameter change rate; Calculating the standard deviation of the diameter change rate deviations of all monitoring points to obtain the growth uniformity of the silicon core rod within the second preset time length; determining whether to spatially splice the abnormal growth areas based on whether there are non-overlapping areas in the abnormal growth areas; Determining whether to spatially stitch the abnormal growth region includes: If there are non-overlapping areas in the abnormal growth areas, determining that the abnormal growth areas need to be spatially spliced; If there is no non-overlapping area in the abnormal growth area, it is determined that the abnormal growth area does not need to be spatially spliced; Determining whether to control the air intake by a local control method or an overall control method based on a comparison result of the growth abnormality region with non-overlapping regions and the coverage of the growth abnormality region after spatial splicing, and the overall growth rate of the silicon core rod and a preset overall growth rate; Based on whether there are conflicting abnormal characteristics in the local growth abnormal area, it is determined to adjust the intake flow or intake angle of the intake device corresponding to the local growth abnormal area, or based on the consistency of the abnormal characteristics of the overall growth area, it is determined to adjust the distribution position or distribution spacing of the overall intake device.

2. The polysilicon deposition gas inlet device control method based on silicon core rod growth characteristics according to claim 1, characterized in that: Determining and obtaining data on abnormal growth areas of a silicon core rod or obtaining data on the overall growth rate of the silicon core rod includes: If the surface temperature distribution uniformity of the silicon core rod within the first preset time period is greater than or equal to the preset distribution uniformity or the growth uniformity of the silicon core rod within the second preset time period is greater than or equal to the preset growth uniformity, determining to obtain the abnormal growth area data of the silicon core rod; If the surface temperature distribution uniformity of the silicon core rod within the first preset time period is less than the preset distribution uniformity and the growth uniformity of the silicon core rod within the second preset time period is less than the preset growth uniformity, it is determined to obtain the overall growth rate data of the silicon core rod.

3. The polysilicon deposition gas inlet device control method based on silicon core rod growth characteristics according to claim 2, characterized in that: The spatial splicing of the abnormal growth areas includes: Establish a three-dimensional coordinate system with the central axis of the silicon core rod as the coordinate axis; Determine the coordinates of the boundary points of each abnormal growth area and its range parameters in the circumferential direction and the axial direction by measurement or calculation; According to the boundary point coordinates and range parameters of each abnormal growth area, boundary matching is performed to identify the connection relationship between adjacent abnormal growth areas; Based on the coordinates of the boundary points and the connection relationship of each abnormal growth region, the abnormal growth regions are spatially spliced ​​to form a continuous region.

4. The polysilicon deposition gas inlet device control method based on silicon core rod growth characteristics according to claim 3, characterized in that: Determining whether to control the intake air using a local control method or an overall control method includes: If the abnormal growth area in the non-overlapping area and the abnormal growth area after spatial splicing do not cover the silicon core rod around the entire circle and the overall growth rate of the silicon core rod is greater than or equal to the preset overall growth rate, it is determined to control the air intake by the local control method; If any of the growth abnormality areas in the non-overlapping areas and the growth abnormality areas after spatial splicing cover the silicon core rod or the overall growth rate of the silicon core rod is less than the preset overall growth rate, it is determined to control the air intake using the overall control method.

5. The polysilicon deposition gas inlet device control method based on silicon core rod growth characteristics according to claim 4, characterized in that: Determining and adjusting the intake flow rate or intake angle of the intake device corresponding to the local abnormal growth area includes: If the local abnormal growth region has conflicting abnormal features, determining to adjust the intake angle of the intake device corresponding to the local abnormal growth region; If the local abnormal growth region does not have conflicting abnormal features, it is determined to adjust the intake flow of the intake device corresponding to the local abnormal growth region.

6. The polysilicon deposition gas inlet device control method based on silicon core rod growth characteristics according to claim 5, characterized in that: Determining and adjusting the distribution position or distribution spacing of the integral air intake device includes: If the degree of consistency of the abnormal characteristics of the entire growth area is less than or equal to a preset degree of consistency, determining to adjust the distribution position of the entire air intake device; If the degree of consistency of the abnormal characteristics of the entire growth area is greater than a preset degree of consistency, it is determined to adjust the distribution spacing of the entire air intake device.

7. A polysilicon deposition air inlet device applied to the polysilicon deposition air inlet device control method based on silicon core rod growth characteristics according to any one of claims 1 to 6, characterized in that: include: An air inlet pipe, comprising a closed end located in the deposition furnace, an interface end connected to the silane air inlet, an outer pipe and an inner pipe, wherein the outer pipe is sleeved on the inner pipe, the inner pipe is used to circulate silane gas, and a sealed cavity is formed between the outer pipe and the inner pipe for heat insulation; Exhaust holes are evenly spaced along the extension direction of the air inlet pipe, with the opening direction inclined downward at 30°-60° to the axis of the silicon core rod, for uniform gas distribution; A connecting piece is located at the interface end and is used to connect the air inlet pipe to the silane air inlet.

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