Control Method, Device and Crystal Pulling System for Crystal Pulling Process

Abstract

The present application provides a control method, device, and crystal pulling system for a crystal pulling process. The method includes: constructing a transport numerical model of a target object in a single crystal furnace, where the target object includes at least one of the following: oxygen impurities and phosphorus dopants, and the transport numerical model of the target object is used to reflect the distribution of the target object inside the single crystal furnace under different process conditions and magnetic field structures; generating a plurality of characteristic parameters corresponding to the target object under a plurality of process conditions and a plurality of magnetic field structure parameters according to the transport numerical model of the target object, where the characteristic parameters are used to characterize the physical properties of the target object; screening target process conditions and target magnetic field structure parameters from the plurality of process conditions and the plurality of magnetic field structure parameters according to the plurality of characteristic parameters, so as to control the crystal pulling process of the single crystal furnace under the target process conditions and the target magnetic field structure parameters, thereby solving the problem in the prior art that the electrical properties of the crystal cannot be guaranteed in the Czochralski method for growing single crystal silicon rods.

Description

Technical Field

[0001] The present application relates to the technical field of Czochralski single crystal technology, and in particular, to a control method, device, and crystal pulling system for a crystal pulling process. Background Technique

[0002] The Czochralski crystal growth process is an important technology and method for pulling semiconductor single crystal rods, capable of preparing high-purity and high-quality silicon single crystals, and is an important foundation in the semiconductor material industry.

[0003] As an important semiconductor material, the growth technology of single crystal silicon has a profound impact on the manufacturing of high-purity silicon, solar cells, and fields such as aerospace and microelectronics. The Czochralski method is also the most important current growth technology. The surface of an N-type single crystal rod has a good energy band structure and is commonly used in the N-type region of solar cell manufacturing. And N-type doping is a key factor determining the quality of the single crystal rod, and the distribution uniformity of dopants (P, As, B, Sb) directly affects the electrical properties of the single crystal silicon.

[0004] However, many challenges are encountered during the growth process of single crystal rods. Among them: oxygen impurities introduced during the Czochralski single crystal growth process will reduce the minority carrier lifetime of the silicon wafer, which is not conducive to improving the efficiency of photovoltaic cells. The high concentration of oxygen impurities on the crystal surface will lead to poor surface energy band structure; moreover, the uneven distribution of phosphorus elements in N-type silicon wafers will affect the resistivity of the silicon wafers and its distribution, resulting in fluctuations and attenuation of the minority carrier lifetime during the crystal growth process, thereby affecting the electrical properties of the crystal. Summary of the Invention

[0005] The main purpose of the present application is to provide a control method, device, and crystal pulling system for a crystal pulling process, so as to at least solve the problem that the electrical properties of the crystal cannot be guaranteed in the prior art in the Czochralski single crystal rod growth process.

[0006] To achieve the above object, according to one aspect of the present application, a control method for a crystal pulling process is provided, including: constructing a transport numerical model of a target object in a single crystal furnace, where the target object includes at least one of oxygen impurities and phosphorus dopants, and the transport numerical model of the target object is used to at least reflect the distribution of the target object inside the single crystal furnace under different process conditions and magnetic field structures; generating a plurality of characteristic parameters corresponding to the target object under a plurality of process conditions and a plurality of magnetic field structure parameters according to the transport numerical model of the target object, where the characteristic parameters are used to characterize the physical properties of the target object; screening target process conditions and target magnetic field structure parameters from the plurality of process conditions and the plurality of magnetic field structure parameters according to the plurality of characteristic parameters, so as to control the single crystal furnace to perform the crystal pulling process under the target process conditions and the target magnetic field structure parameters.

[0007] Optionally, the target object includes oxygen impurities. The construction of the transport numerical model of the target object in the single crystal furnace includes: according to a plurality of first historical experimental data under a plurality of the process conditions and a plurality of the magnetic field structure parameters, and the non-equilibrium molecular dynamics theory, establishing a first theoretical relationship of the dissolution rate of oxygen on the contact surface between the crucible and the silicon melt in the single crystal furnace under different process conditions and magnetic field structures, wherein the plurality of first historical experimental data includes: the dissolution rate of oxygen in the single crystal furnace, and the oxygen concentration in the single crystal furnace; according to the first theoretical relationship, constructing the transport numerical model of the oxygen impurities.

[0008] Optionally, the target object includes phosphorus dopants. The construction of the transport numerical model of the target object in the single crystal furnace includes: according to a plurality of second historical experimental data under a plurality of the process conditions and a plurality of the magnetic field structure parameters, constructing the transport numerical model of the phosphorus dopants, wherein the plurality of second historical experimental data includes: the concentration of phosphorus dopants in the single crystal furnace, and the resistivity of the single crystal silicon prepared by the single crystal furnace.

[0009] Optionally, generating a plurality of characteristic parameters corresponding to the target object under a plurality of process conditions and a plurality of magnetic field structure parameters according to the transport numerical model of the target object includes: calculating according to the transport numerical model of the oxygen impurities to obtain calculation results corresponding to a plurality of melt systems, wherein the calculation results include the dynamic relationship between the input set and the output set of the transport numerical model, and the dynamic relationship is used to reflect the physical properties corresponding to the plurality of melt systems, any two of the melt systems have different dynamic characteristics, and the plurality of melt systems respectively correspond to a plurality of the process conditions and a plurality of the magnetic field structure parameters, wherein: when the target object includes oxygen impurities, the physical properties at least include one of the following: the occurrence characteristics of oxygen impurities in the raw materials, the dissolution characteristics of oxygen impurities on the crucible wall surface, the transport characteristics of oxygen impurities inside the silicon melt, the segregation characteristics of oxygen impurities at the crystallization interface, the evaporation characteristics of oxygen impurities on the melt surface, and the distribution law of oxygen impurities along the crystal radial and axial directions; when the target object includes oxygen impurities, the physical properties at least include one of the following: the occurrence characteristics of oxygen impurities in the raw materials, the dissolution characteristics of oxygen impurities on the crucible wall surface, the transport characteristics of oxygen impurities inside the silicon melt, the segregation characteristics of oxygen impurities at the crystallization interface, the evaporation characteristics of oxygen impurities on the melt surface, and the distribution law of oxygen impurities along the crystal radial and axial directions; determining a plurality of characteristic parameters corresponding to the plurality of melt systems respectively according to the calculation results, a plurality of preset process conditions and a plurality of preset magnetic field structure parameters.

[0010] Optionally, determining a plurality of characteristic parameters corresponding to a plurality of melt systems according to the calculation result, a plurality of preset process conditions, and a plurality of preset magnetic field structure parameters includes: obtaining characteristic parameters corresponding to a plurality of melt systems according to the calculation result, a plurality of preset rotation speeds, and a plurality of preset hook-shaped magnetic field structure parameters, where the preset rotation speeds at least include: the crucible rotation speed of the single crystal furnace and the crystal rotation speed of the single crystal furnace, and the preset hook-shaped magnetic field structure parameters at least include: the position and intensity of the hook-shaped magnetic field, and the characteristic parameters include at least one of the following: the concentration distribution of oxygen impurities, the crystal growth rate in the single crystal furnace, and the temperature distribution in the single crystal furnace.

[0011] Optionally, screening target process conditions and target magnetic field structure parameters from the plurality of process conditions and the plurality of magnetic field structure parameters according to the plurality of characteristic parameters includes: determining whether the plurality of characteristic parameters meet corresponding preset conditions; when a first target characteristic parameter among the plurality of characteristic parameters meets a target preset condition, determining the process condition and the magnetic field structure parameter corresponding to the first target characteristic parameter as the target process condition and the target magnetic field structure parameter.

[0012] Optionally, the control method further includes: an adjustment step: when the first target characteristic parameter does not meet the target preset condition, outputting an adjustment signal to the single crystal furnace to adjust the process condition and the magnetic field structure parameter corresponding to the first target characteristic parameter; a determination step: re-determining an updated first target characteristic parameter corresponding to the target object under the adjusted process condition and / or magnetic field structure parameter according to the transport numerical model of the target object; a judgment step: determining whether the first target characteristic parameter meets the target preset condition; when the first target characteristic parameter does not meet the target preset condition, repeating the adjustment step, the determination step, and the judgment step until the first target characteristic parameter meets the target preset condition and then stopping.

[0013] Optionally, when the single crystal furnace receives the adjustment signal, single crystal silicon growth is performed under the adjusted process conditions and / or magnetic field structure parameters. The determining step includes: generating, according to the transport numerical model of the target object, a second target characteristic parameter corresponding to the target object under the adjusted process conditions and / or magnetic field structure parameters, where the second target characteristic parameter is a characteristic parameter different from the first target characteristic parameter among a plurality of the characteristic parameters; obtaining target experimental data of the single crystal silicon growth, where the target experimental data has the same characteristic type as the second target characteristic parameter; determining whether the difference between the second target characteristic parameter and the experimental data satisfies a preset difference; and when the preset difference is satisfied, determining the second target characteristic parameter as the updated first target characteristic parameter.

[0014] According to another aspect of the present application, there is provided a process control device for a single crystal silicon rod, including: a construction module for constructing a transport numerical model of a target object in a single crystal furnace, where the target object includes at least one of an oxygen impurity and a phosphorus dopant, and the transport numerical model of the target object is used to at least reflect the distribution of the target object inside the single crystal furnace under different process conditions and magnetic field structures; a generation module for generating, according to the transport numerical model of the target object, a plurality of characteristic parameters corresponding to the target object under a plurality of process conditions and a plurality of magnetic field structure parameters, where the characteristic parameters are used to characterize the physical properties of the target object; and a control module for screening target process conditions and target magnetic field structure parameters from the plurality of process conditions and the plurality of magnetic field structure parameters according to the plurality of characteristic parameters, so as to control the single crystal furnace to perform a crystal pulling process under the target process conditions and the target magnetic field structure parameters.

[0015] According to still another aspect of the present application, there is provided a crystal pulling system, including: a single crystal furnace, one or more processors, a memory, and one or more programs, where the one or more processors are electrically connected to the single crystal furnace, the one or more programs are stored in the memory and are configured to be executed by the one or more processors, and the one or more programs include a control method for executing the crystal pulling process described above.

[0016] Applying the technical solution of the present application, a transport numerical model of target objects such as oxygen impurities and phosphorus dopants is established, which is used to at least reflect the distribution of the target objects inside the single crystal furnace under different process conditions and magnetic field structures. Based on the above transport numerical model, the physical properties of the target objects in the melt and crystal during different stages of single crystal silicon growth under different process conditions and magnetic field structures are studied, so as to develop a transport control technology for target objects such as oxygen impurities and phosphorus dopants in the magnetic-controlled N-type single crystal silicon pulling growth. Furthermore, through process parameter optimization and magnetic field structure matching, not only can the concentration of oxygen impurities in the crystal be reduced and evenly distributed to reduce the attenuation rate of the minority carrier lifetime during crystal growth, which is beneficial to improving the efficiency of photovoltaic cells, but also the distribution uniformity of phosphorus in N-type single crystal silicon can be improved to improve the resistivity uniformity of N-type single crystal silicon and slow down or avoid the fluctuation and attenuation of the minority carrier lifetime during crystal growth. Brief Description of the Drawings

[0017] The specification drawings forming a part of the present application are used to provide a further understanding of the present application. The schematic embodiments of the present application and their descriptions are used to explain the present application and do not constitute an improper limitation to the present application. In the drawings:

[0018] Figure 1 The hardware structure block diagram of a mobile terminal showing a control method for performing a crystal pulling process provided in an embodiment of the present application is shown;

[0019] Figure 2 The flowchart showing a control method for a crystal pulling process provided in an embodiment of the present application is shown;

[0020] Figure 3 The structure block diagram of a control device for a crystal pulling process provided in an embodiment of the present application is shown. Detailed Description of the Embodiments

[0021] It should be noted that, without conflict, the embodiments in the present application and the features in the embodiments can be combined with each other. The present application will be described in detail below with reference to the drawings and in combination with the embodiments.

[0022] In order to enable those skilled in the art to better understand the solution of the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present application.

[0023] It should be noted that the terms "first", "second", etc. in the description, claims and above-mentioned drawings of this application are used to distinguish similar objects, and do not necessarily need to describe a specific order or sequence. It should be understood that the data used in this way can be interchanged under appropriate circumstances, so as to implement the embodiments of the present application described herein. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusion. For example, a process, method, system, product or device that includes a series of steps or units does not necessarily have to be limited to those steps or units clearly listed, but may include other steps or units not clearly listed or inherent to these processes, methods, products or devices.

[0024] As introduced in the background art, in the traditional Czochralski single crystal growth process in the prior art, the oxygen impurities introduced will reduce the minority carrier lifetime of the silicon wafer, which is not conducive to improving the efficiency of photovoltaic cells. The high concentration of oxygen impurities on the crystal surface will lead to poor surface energy band structure. Moreover, the uneven distribution of phosphorus elements in N-type silicon wafers will affect the resistivity of the silicon wafers and its distribution, resulting in fluctuations and attenuation of the minority carrier lifetime during the crystal growth process, thereby affecting the electrical properties of the crystal. To solve the above problems, the embodiments of this application provide a control method, device, storage medium and crystal pulling system for crystal pulling processes.

[0025] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention.

[0026] The method embodiments provided in the embodiments of this application can be executed on a mobile terminal, a computer terminal or a similar computing device. Taking running on a mobile terminal as an example, Figure 1 is a hardware structure block diagram of a mobile terminal for a control method of a crystal pulling process according to an embodiment of the present invention. As Figure 1 shown, the mobile terminal may include one or more ( Figure 1 only one is shown in Figure 1 processors 102 (the processors 102 may include, but are not limited to, processing devices such as a microprocessor MCU or a programmable logic device FPGA) and a memory 104 for storing data. Among them, the above-mentioned mobile terminal may further include a transmission device 106 for communication functions and an input / output device 108. Those of ordinary skill in the art can understand that Figure 1 the structure shown in Figure 1 is only schematic and does not limit the structure of the above-mentioned mobile terminal. For example, the mobile terminal may further include more or fewer components than those shown in

[0027] The memory 104 can be used to store computer programs, for example, software programs and modules of application software, such as the computer program corresponding to the control method of the crystal pulling process in the embodiments of the present invention. The processor 102 executes various functional applications and data processing by running the computer program stored in the memory 104, that is, implements the above-mentioned method. The memory 104 may include a high-speed random access memory, and may also include a non-volatile memory, such as one or more magnetic storage devices, flash memories, or other non-volatile solid-state memories. In some instances, the memory 104 may further include a memory remotely disposed relative to the processor 102, and these remote memories may be connected to the mobile terminal through a network. Examples of the above-mentioned network include, but are not limited to, the Internet, an enterprise intranet, a local area network, a mobile communication network, and combinations thereof. The transmission device 106 is used to receive or send data via a network. Specific examples of the above-mentioned network may include a wireless network provided by a communication provider of the mobile terminal. In one instance, the transmission device 106 includes a network adapter (Network Interface Controller, abbreviated as NIC), which can be connected to other network devices through a base station and thus can communicate with the Internet. In one instance, the transmission device 106 may be a radio frequency (Radio Frequency, abbreviated as RF) module, which is used to communicate with the Internet wirelessly.

[0028] In this embodiment, a control method for a crystal pulling process running on a mobile terminal, a computer terminal, or a similar computing device is provided. It should be noted that the steps shown in the flowchart of the accompanying drawings can be executed in a computer system such as a set of computer-executable instructions, and although the logical order is shown in the flowchart, in some cases, the steps shown or described can be executed in a different order than here.

[0029] Figure 2 It is a flowchart of the control method for the crystal pulling process according to the embodiments of the present application. As Figure 2 shown, the method includes the following steps:

[0030] Step S201, constructing a transport numerical model of a target object in a single crystal furnace, where the target object includes at least one of oxygen impurities and phosphorus dopants. The transport numerical model of the target object is used to at least reflect the distribution of the target object inside the single crystal furnace under different process conditions and magnetic field structures;

[0031] Specifically, the above-mentioned transport numerical model can be used to study the physical properties of the above-mentioned target objects in the melt and the crystal at different stages of single crystal silicon growth under different process conditions and magnetic field structures, so as to develop a transport control technology for target objects such as oxygen impurities and phosphorus dopants in the magnetic-controlled N-type single crystal pulling growth.

[0032] Step S202: Generate multiple characteristic parameters corresponding to the target object under multiple process conditions and multiple magnetic field structure parameters according to the transport numerical model of the target object, where the characteristic parameters are used to characterize the physical properties of the target object.

[0033] Specifically, according to the constructed transport numerical model of the target object, characteristic parameters of the target object under different process conditions and magnetic field structure parameters can be generated. These characteristic parameters can characterize the physical properties of the target object, including but not limited to the transport characteristics inside the silicon melt, the segregation characteristics at the crystallization interface, the evaporation characteristics on the surface of the silicon melt, and the distribution laws along the radial and axial directions of the crystal. By comparing and analyzing these parameters, the influence laws of the consumption and distribution of target objects such as oxygen impurities and phosphorus dopants in different stages of single-crystal silicon growth under different process conditions and magnetic field structure parameters can be studied.

[0034] Step S203: Determine the target process conditions and target magnetic field structure parameters according to the multiple characteristic parameters, multiple process conditions and multiple magnetic field structure parameters, and control the single-crystal furnace to perform the crystal pulling process under the target process conditions and target magnetic field structure parameters.

[0035] Specifically, based on the generated characteristic parameters, a set of optimal target process conditions and target magnetic field structure parameters can be determined in combination with historical experimental data. The selection of these parameters aims to improve the distribution uniformity of the target object in N-type single-crystal silicon and avoid the influence of uneven distribution on the minority carrier lifetime during the crystal growth process. Then, the determined target process conditions and magnetic field structure parameters are applied to the actual control of the single-crystal furnace. By adjusting parameters such as the crucible rotation speed, crystal rotation speed, position and intensity of the hook-shaped magnetic field, etc., it is ensured that the single-crystal furnace operates under optimal conditions. This control method can specifically solve problems such as uneven distribution of oxygen impurities and difficult control of phosphorus dopant transport in the existing process, thereby significantly improving the quality of the Czochralski single-crystal silicon rod.

[0036] Through this embodiment, a transport numerical model of target objects such as vertical oxygen impurities and phosphorus dopants can be established and utilized to reflect the distribution of the target object inside the single-crystal furnace under different process conditions and magnetic field structures. Based on the above transport numerical model, the physical properties of the target object in the melt and crystal during different stages of single-crystal silicon growth under different process conditions and magnetic field structures are studied, so as to develop a transport regulation technology for target objects such as oxygen impurities and phosphorus dopants in the magnetic-controlled N-type single-crystal silicon pulling growth. Furthermore, through process parameter optimization and magnetic field structure matching, not only can the reduction and uniform distribution of oxygen impurity concentration in the crystal be achieved to reduce the attenuation rate of the minority carrier lifetime during the crystal growth process, which is beneficial to improving the efficiency of photovoltaic cells, but also the distribution uniformity of phosphorus in N-type single-crystal silicon can be improved to improve the resistivity uniformity of N-type single-crystal silicon and slow down or avoid the fluctuation and attenuation of the minority carrier lifetime during the crystal growth process.

[0037] On the one hand, the oxygen impurities introduced during the Czochralski single-crystal silicon growth process will reduce the minority carrier lifetime of the silicon wafer, which is not conducive to improving the efficiency of photovoltaic cells. To address this problem, when the above target object includes oxygen impurities, the above step S201 can be achieved through the following steps: Based on multiple first historical experimental data under multiple process conditions and multiple magnetic field structure parameters and the non-equilibrium molecular dynamics theory, establish a first theoretical relationship for the dissolution rate of oxygen on the contact surface between the crucible and the silicon melt in the single-crystal furnace under different process conditions and magnetic field structures. Among them, the multiple first historical experimental data include: the dissolution rate of oxygen in the single-crystal furnace and the oxygen concentration in the single-crystal furnace, and based on the first theoretical relationship, construct a numerical model for the transport of oxygen impurities.

[0038] Exemplarily, based on the non-equilibrium molecular dynamics theory and relevant experimental data, this application constructs an atomic-scale model for the dissolution of quartz in the silicon melt, compares and studies the variation laws of the oxygen dissolution rate and oxygen concentration with time at different temperatures, reveals the influence laws of temperature and oxygen concentration on the oxygen dissolution rate, obtains a theoretical relationship for the dissolution rate of oxygen on the contact surface between quartz and the silicon melt, and establishes a numerical model that can accurately describe the generation, consumption, and transport of oxygen impurities during the growth of magnetron N-type single-crystal silicon by the Czochralski method.

[0039] On the other hand, the distribution of phosphorus elements in the N-type silicon wafer has a significant impact on the resistivity of the silicon wafer and its distribution, which is closely related to the transport process of phosphorus dopants during the single-crystal silicon growth process. To address this problem, when the target object includes phosphorus dopants, the above step S201 can be achieved through the following steps: Based on multiple second historical experimental data under multiple process conditions and multiple magnetic field structure parameters, construct a numerical model for the transport of phosphorus dopants. Among them, the multiple second historical experimental data include: the concentration of phosphorus dopants in the single-crystal furnace and the resistivity of the single-crystal silicon prepared by the single-crystal furnace.

[0040] Exemplarily, this application considers the volatilization of phosphorus elements at the free surface, segregation at the crystallization interface, and free diffusion inside the crystal. Based on the experimental data related to the volatilization loss of phosphorus from the melt surface during the Czochralski process, the segregation characteristics of phosphorus elements at the crystallization interface, and the diffusion coefficient of phosphorus elements inside the crystal, establish a numerical model for the transport of dopant phosphorus elements during the growth of magnetron N-type single-crystal silicon by the Czochralski method.

[0041] In order to generate characteristic parameters for characterizing the physical properties of the target object, step S202 of the present application can be implemented through the following steps: calculating according to the transport numerical model of the target object to obtain calculation results corresponding to multiple melt systems, where the calculation results include the dynamic relationship between the input set and the output set of the transport numerical model, and the dynamic relationship is used to reflect the physical properties corresponding to multiple melt systems, any two melt systems have different dynamic characteristics, and multiple melt systems respectively correspond to multiple preset process conditions and multiple magnetic field structure parameters; determining multiple characteristic parameters respectively corresponding to multiple melt systems according to the calculation results, multiple preset process conditions and multiple magnetic field structure parameters.

[0042] In some optional embodiments, determining multiple characteristic parameters corresponding to multiple melt systems according to the calculation results, multiple preset process conditions and multiple preset magnetic field structure parameters includes: obtaining characteristic parameters corresponding to multiple melt systems according to the calculation results, multiple preset rotation speeds and multiple preset hook-shaped magnetic field structure parameters, where the preset rotation speeds at least include: the crucible rotation speed of the single crystal furnace and the crystal rotation speed of the single crystal furnace, and the preset hook-shaped magnetic field structure parameters at least include: the position and intensity of the hook-shaped magnetic field, and the characteristic parameters include at least one of the following: the concentration distribution of oxygen impurities, the crystal growth rate in the single crystal furnace, and the temperature distribution in the single crystal furnace.

[0043] In the above optional embodiment, the established transport numerical model of the target object can be used to study and analyze the physical characteristics of the target object under different process conditions (such as crucible rotation speed, crystal rotation speed, temperature, pressure, etc.) and hook-shaped magnetic field structures (magnetic field position, intensity, distribution, etc.), so as to identify the key parameters affecting the distribution of the target object.

[0044] Specifically, when the target object includes oxygen impurities, the physical properties of oxygen impurities can include one of the following: the occurrence characteristics of oxygen impurities in the raw material, the dissolution characteristics of oxygen impurities on the crucible wall surface, the transport characteristics of oxygen impurities inside the silicon melt, the segregation characteristics of oxygen impurities at the crystallization interface, the evaporation characteristics of oxygen impurities on the melt surface, and the distribution law of oxygen impurities along the radial and axial directions of the crystal. In the present application, based on the above transport numerical model of oxygen impurities and the crystal growth experiment, the occurrence characteristics of oxygen impurities in the raw material, the segregation characteristics of oxygen impurities at the crystallization interface, the evaporation characteristics of oxygen impurities on the free surface of the melt and the distribution law along the radial and axial directions of the crystal are studied, the free surface interface effect is analyzed, and thus the influence law of process parameters such as crucible rotation speed, crystal rotation speed, hook-shaped magnetic field position and intensity on the generation, consumption and distribution of oxygen impurities in different stages of single crystal growth is analyzed to obtain the key parameters affecting the distribution of oxygen impurities, especially the regulation effect of the hook-shaped magnetic field on oxygen transport.

[0045] In the case where the above target object includes a phosphorus dopant, the physical properties of the phosphorus dopant may include one of the following: the transport property of the phosphorus dopant inside the silicon melt, the segregation property of the phosphorus dopant at the crystallization interface, the evaporation property of the phosphorus dopant on the surface of the silicon melt, and the distribution law of the phosphorus dopant along the radial and axial directions of the crystal.

[0046] Specifically, based on the above transport numerical model of the phosphorus dopant and crystal growth experiments, with the aim of suppressing the volatilization loss of phosphorus from the melt surface during the melting material and pulling processes, the segregation property of phosphorus at the crystallization interface, the evaporation property on the free surface of the melt, and the distribution law along the radial and axial directions of the crystal are studied, and the volatilization loss of phosphorus from the melt surface during the melting material and pulling processes is suppressed. Thus, the influence laws of process parameters such as crucible rotation speed, crystal rotation speed, the position and intensity of the hook-shaped magnetic field on the consumption of the phosphorus dopant and its distribution in the crystal during different stages of single-crystal growth are studied to obtain the key parameters affecting phosphorus distribution, especially the regulation effect of the hook-shaped magnetic field on phosphorus transport.

[0047] In some embodiments, the above step S203 can be specifically implemented through the following steps: determining whether a plurality of characteristic parameters meet corresponding preset conditions; and when the first target characteristic parameter among the plurality of characteristic parameters meets the target preset condition, determining the process condition and the magnetic field structure parameter corresponding to the first target characteristic parameter as the target process condition and the target magnetic field structure parameter.

[0048] Specifically, numerical simulation is carried out using the established model to analyze the distribution laws of oxygen impurities and phosphorus elements under different process conditions and magnetic field structures, and analyze how these distributions affect their turbulent transport inside the melt and their segregation at the crystallization interface. Then, preset conditions are set through the characteristic parameters of the historical silicon melt system with stable transport, and by determining whether the characteristic parameters obtained in step S202 meet the preset conditions, the optimal combination of magnetic field parameters is found from the historical experimental data, which can reduce the turbulent transport of oxygen impurities and phosphorus elements inside the melt and control their segregation at the crystallization interface, so as to achieve the optimal distributions of oxygen impurities and phosphorus elements and crystal performance. In addition to magnetic field parameters, process conditions such as crucible rotation speed and crystal rotation speed also need to be determined to cooperate with the action of the magnetic field.

[0049] In some alternative embodiments, the control method in the embodiments of the present application further includes: an adjustment step: when the target characteristic parameter does not meet the target preset condition, output an adjustment signal to the single crystal furnace to adjust the process conditions and magnetic field structure parameters corresponding to the first target characteristic parameter; a determination step: re-determine the updated target characteristic parameter corresponding to the target object under the adjusted process conditions and / or magnetic field structure parameters according to the transport numerical model of the target object; a judgment step: judge whether the target characteristic parameter meets the target preset condition; when the target characteristic parameter does not meet the target preset condition, repeat the adjustment step, the determination step and the judgment step until the target characteristic parameter meets the target preset condition and then stop.

[0050] Further, when the single crystal furnace receives the adjustment signal, single crystal silicon growth is carried out under the adjusted process conditions and / or magnetic field structure parameters, and then the second target characteristic parameter corresponding to the silicon melt under the adjusted process conditions and / or magnetic field structure parameters can be generated according to the transport numerical model of the target object. The second target characteristic parameter is a characteristic parameter different from the first target characteristic parameter among multiple characteristic parameters; and obtain the target experimental data of single crystal silicon growth, wherein the target experimental data has the same characteristic type as the second target characteristic parameter; then, judge whether the difference between the second target characteristic parameter and the experimental data meets the preset difference, and when the preset difference is met, determine the second target characteristic parameter as the updated first target characteristic parameter.

[0051] Specifically, by adjusting the position and intensity of the hook-shaped magnetic field, the influence of the hook-shaped magnetic field on the distribution of target objects such as oxygen impurities and phosphorus elements can be studied, and the model prediction can be verified through experiments, and the magnetic field configuration can be gradually optimized to find an optimal magnetic field structure parameter, which can effectively improve the distribution uniformity of target objects such as oxygen impurities and phosphorus elements in N-type single crystal silicon. In addition to the magnetic field structure parameters, the process conditions such as the crucible rotation speed and the crystal rotation speed can also be adjusted to cooperate with the action of the magnetic field. The adjustment of these parameters can also be based on the model prediction and experimental verification to ensure that the concentration distribution state of target objects such as oxygen impurities and phosphorus elements can be effectively controlled during the whole growth process. Finally, through continuous collection and analysis of production data, verify whether the adjusted magnetic field structure parameters and process conditions can indeed improve the distribution uniformity of target objects in N-type single crystal silicon.

[0052] Through this series of steps in the embodiments of the present application, the hook-shaped magnetic field can be effectively utilized to improve the distribution uniformity of target objects such as oxygen impurities and phosphorus elements in N-type single crystal silicon, reduce the influence of uneven distribution on the minority carrier lifetime during the crystal growth process, and is beneficial to improving the efficiency of photovoltaic cells.

[0053] The embodiments of the present application further provide a process control device. It should be noted that the process control device in the embodiments of the present application can be used to execute the process control method provided in the embodiments of the present application. The device for implementing the above embodiments and preferred embodiments has been described and will not be repeated here. As used below, the term "module" can be a combination of software and / or hardware that can achieve a predetermined function. Although the devices described in the following embodiments are preferably implemented in software, implementation in hardware, or a combination of software and hardware is also possible and contemplated.

[0054] The process control device provided in the embodiments of the present application will be introduced below.

[0055] Figure 3 is a schematic diagram of the process control device according to the embodiments of the present application. As Figure 3 shown, the device includes:

[0056] A construction module 10, configured to construct a transport numerical model of a target object in a single crystal furnace, where the target object includes at least one of oxygen impurities and phosphorus dopants. The transport numerical model of the target object is used to at least reflect the distribution of the target object inside the single crystal furnace under different process conditions and magnetic field structures;

[0057] A generation module 20, configured to generate a plurality of characteristic parameters corresponding to the target object under a plurality of process conditions and a plurality of magnetic field structure parameters according to the transport numerical model of the target object, where the characteristic parameters are used to characterize the physical properties of the target object;

[0058] A control module 30, configured to screen target process conditions and target magnetic field structure parameters from the plurality of process conditions and the plurality of magnetic field structure parameters according to the plurality of characteristic parameters, so as to control the single crystal furnace to perform a crystal pulling process under the target process conditions and the target magnetic field structure parameters.

[0059] As an optional solution, the target object includes a phosphorus dopant, and the construction module 10 includes: an establishment sub-module, configured to establish a first theoretical relationship of the dissolution rate of oxygen on the contact surface between the crucible and the silicon melt in the single crystal furnace under different process conditions and magnetic field structures according to a plurality of first historical experimental data under a plurality of process conditions and a plurality of magnetic field structure parameters and the non-equilibrium molecular dynamics theory, where the plurality of first historical experimental data includes: the dissolution rate of oxygen in the single crystal furnace, and the oxygen concentration in the single crystal furnace; a first construction sub-module, configured to construct a transport numerical model of oxygen impurities according to the first theoretical relationship.

[0060] As another alternative, the target object includes oxygen impurities, and the building module 10 includes: a second building sub-module, configured to construct a numerical transport model of the phosphorus dopant according to a plurality of second historical experimental data under a plurality of process conditions and a plurality of magnetic field structure parameters, wherein the plurality of second historical experimental data includes: the concentration of the phosphorus dopant in the single crystal furnace, and the resistivity of the single crystal silicon prepared by the single crystal furnace.

[0061] In an alternative solution, the generating module 20 includes: a calculating sub-module, configured to calculate according to the numerical transport model of the oxygen impurities to obtain calculation results corresponding to a plurality of melt systems, wherein the calculation results include the dynamic relationship between the input set and the output set of the numerical transport model, and the dynamic relationship is used to reflect the physical properties corresponding to the plurality of melt systems, and any two melt systems have different dynamic characteristics, and the plurality of melt systems respectively correspond to a plurality of process conditions and a plurality of magnetic field structure parameters, wherein: when the target object includes oxygen impurities, the physical properties include at least one of the following: the occurrence characteristics of oxygen impurities in the raw materials, the dissolution characteristics of oxygen impurities on the crucible wall surface, the transport characteristics of oxygen impurities inside the silicon melt, the segregation characteristics of oxygen impurities at the crystallization interface, the evaporation characteristics of oxygen impurities on the melt surface, and the distribution law of oxygen impurities along the radial and axial directions of the crystal; when the target object includes oxygen impurities, the physical properties include at least one of the following: the occurrence characteristics of oxygen impurities in the raw materials, the dissolution characteristics of oxygen impurities on the crucible wall surface, the transport characteristics of oxygen impurities inside the silicon melt, the segregation characteristics of oxygen impurities at the crystallization interface, the evaporation characteristics of oxygen impurities on the melt surface, and the distribution law of oxygen impurities along the radial and axial directions of the crystal; a first determining sub-module, configured to determine a plurality of characteristic parameters corresponding to the plurality of melt systems according to the calculation results, the plurality of preset process conditions, and the plurality of preset magnetic field structure parameters.

[0062] In an alternative solution, the first determining sub-module is configured to: obtain characteristic parameters corresponding to the plurality of melt systems according to the calculation results, the plurality of preset rotation speeds, and the plurality of preset hook-shaped magnetic field structure parameters, wherein the preset rotation speeds at least include: the rotation speed of the crucible of the single crystal furnace, and the rotation speed of the crystal of the single crystal furnace, and the preset hook-shaped magnetic field structure parameters at least include: the position and intensity of the hook-shaped magnetic field, and the characteristic parameters include at least one of the following: the concentration distribution of oxygen impurities, the crystal growth rate in the single crystal furnace, and the temperature distribution in the single crystal furnace.

[0063] In an alternative solution, the control module 30 includes: a judging sub-module, configured to judge whether the plurality of characteristic parameters meet the corresponding preset conditions; a second determining sub-module, configured to, when the first target characteristic parameter meets the target preset conditions, determine the process conditions and the magnetic field structure parameters corresponding to the first target characteristic parameter as the target process conditions and the target magnetic field structure parameters.

[0064] In an alternative solution, the process control device of the embodiment of the present application further includes: an adjustment module, configured to output an adjustment signal to the single crystal furnace when the first target characteristic parameter does not meet the target preset condition, so as to adjust the process condition and the magnetic field structure parameter corresponding to the first target characteristic parameter; a fourth determination sub-module, configured to re-determine the updated first target characteristic parameter corresponding to the silicon melt under the adjusted process condition and / or magnetic field structure parameter according to the transport numerical model of the target object; a second judgment sub-module, configured to judge whether the first target characteristic parameter meets the target preset condition; a loop sub-module, configured to repeat the adjustment step, the determination step, and the judgment step when the first target characteristic parameter does not meet the target preset condition until the first target characteristic parameter meets the target preset condition and then stop.

[0065] In an alternative solution, when receiving the adjustment signal, the single crystal furnace grows single crystal silicon through the adjusted process condition and / or magnetic field structure parameter. The fourth determination sub-module includes: a generation sub-module, configured to generate a second target characteristic parameter corresponding to the silicon melt under the adjusted process condition and / or magnetic field structure parameter according to the transport numerical model of the target object; an acquisition sub-module, configured to acquire the target experimental data of single crystal silicon growth, where the target experimental data and the second target characteristic parameter have the same characteristic type; a third judgment sub-module, configured to judge whether the difference between the second target characteristic parameter and the experimental data meets the preset difference; when the preset difference is met, determine the second target characteristic parameter as the updated first target characteristic parameter.

[0066] In this embodiment, the transport numerical model of target objects such as oxygen impurities and phosphorus dopants is established by the construction module 10, which is used to at least reflect the distribution of the target object inside the single crystal furnace under different process conditions and magnetic field structures. The generation module 20 and the control module 30 are used to study the physical properties of the target object in the melt and crystal during different stages of single crystal silicon growth under different process conditions and magnetic field structures based on the above transport numerical model, so as to develop the transport control technology for target objects such as oxygen impurities and phosphorus dopants in the magnetic-controlled N-type single crystal silicon pulling growth. Furthermore, through process parameter optimization and magnetic field structure matching, not only can the reduction and uniform distribution of oxygen impurity concentration in the crystal be achieved to reduce the attenuation rate of minority carrier lifetime during crystal growth, which is beneficial to improving the efficiency of photovoltaic cells, but also the distribution uniformity of phosphorus in N-type single crystal silicon can be improved to improve the resistivity uniformity of N-type single crystal silicon and slow down or avoid the fluctuation and attenuation of minority carrier lifetime during crystal growth.

[0067] The process control device includes a processor and a memory. The above-mentioned building block 10, generation module 20, control module 30, etc. are all stored in the memory as program units, and the processor executes the above program units stored in the memory to implement corresponding functions. The above modules are all located in the same processor; alternatively, the above modules are separately located in different processors in any combined form.

[0068] The processor contains a kernel, and the kernel retrieves the corresponding program units from the memory. One or more kernels can be set, and by adjusting the kernel parameters, the problem that the electrical properties of the crystal cannot be guaranteed in the Czochralski single crystal ingot growth process in the prior art can be solved.

[0069] The memory may include non-permanent memory in a computer-readable medium, forms such as random access memory (RAM) and / or non-volatile memory, such as read-only memory (ROM) or flash memory (flash RAM), and the memory includes at least one memory chip.

[0070] An embodiment of the present invention provides a computer-readable storage medium, and the computer-readable storage medium includes a stored program. Among them, when the program runs, it controls the device where the computer-readable storage medium is located to execute the control method of the crystal pulling process.

[0071] Specifically, the control method of the crystal pulling process includes:

[0072] Step S201, construct a transport numerical model of the target object in the single crystal furnace, where the target object includes at least one of oxygen impurities and phosphorus dopants. Among them, the transport numerical model of the target object is used to at least reflect the distribution of the target object inside the single crystal furnace under different process conditions and magnetic field structures;

[0073] Specifically, the above transport numerical model can be used to study the physical properties of the above target object in the melt and crystal at different stages of single crystal silicon growth under different process conditions and magnetic field structures, so as to develop a transport regulation technology for target objects such as oxygen impurities and phosphorus dopants in the magnetic-controlled N-type single crystal pulling growth.

[0074] Step S202, according to the transport numerical model of the target object, generate a plurality of characteristic parameters corresponding to the target object under a plurality of process conditions and a plurality of magnetic field structure parameters. Among them, the characteristic parameters are used to characterize the physical properties of the target object;

[0075] Specifically, according to the constructed transport numerical model of the target object, characteristic parameters of the target object under different process conditions and magnetic field structure parameters can be generated. These characteristic parameters can characterize the physical properties of the target object, including but not limited to the transport characteristics inside the silicon melt, the segregation characteristics at the crystallization interface, the evaporation characteristics on the surface of the silicon melt, and the distribution laws along the radial and axial directions of the crystal. By comparing and analyzing these parameters, the influence laws of the consumption of target objects such as oxygen impurities and phosphorus dopants and their distribution in the crystal during different stages of single-crystal silicon growth under the influence of different process conditions and magnetic field structure parameters can be studied.

[0076] Step S203: Determine the target process conditions and target magnetic field structure parameters according to multiple characteristic parameters, multiple process conditions, and multiple magnetic field structure parameters, and control the single-crystal furnace to perform the crystal pulling process under the target process conditions and target magnetic field structure parameters.

[0077] Specifically, based on the generated characteristic parameters, a set of optimal target process conditions and target magnetic field structure parameters can be determined in combination with historical experimental data. The selection of these parameters aims to improve the distribution uniformity of the target object in N-type single-crystalline silicon and avoid the influence of its uneven distribution on the minority carrier lifetime during the crystal growth process. Then, the determined target process conditions and magnetic field structure parameters are applied to the actual control of the single-crystal furnace. By adjusting parameters such as the crucible rotation speed, crystal rotation speed, hook-shaped magnetic field position, and intensity, it is ensured that the single-crystal furnace operates under optimal conditions. This control method can specifically solve problems such as uneven distribution of oxygen impurities and difficult control of phosphorus dopant transport in the existing process, thereby significantly improving the quality of the Czochralski single-crystal silicon rod.

[0078] An embodiment of the present invention provides a crystal pulling system. The system includes a single-crystal furnace, a processor, a memory, and a program stored on the memory and executable on the processor. When the processor executes the program, it implements at least the following steps: constructing a transport numerical model of a target object in the single-crystal furnace, where the target object includes at least one of oxygen impurities and phosphorus dopants, and the transport numerical model of the target object is used to at least reflect the distribution of the target object inside the single-crystal furnace under different process conditions and magnetic field structures; generating multiple characteristic parameters corresponding to the target object under multiple process conditions and multiple magnetic field structure parameters according to the transport numerical model of the target object, where the characteristic parameters are used to characterize the physical properties of the target object; screening the target process conditions and target magnetic field structure parameters from the multiple process conditions and multiple magnetic field structure parameters according to the multiple characteristic parameters to control the single-crystal furnace to perform the crystal pulling process under the target process conditions and target magnetic field structure parameters.

[0079] The present application also provides a computer program product which, when executed on a data processing device, is adapted to execute a program initialized with at least the following method steps: constructing a transport numerical model of a target object in a single crystal furnace, where the target object includes at least one of oxygen impurities and phosphorus dopants, and wherein the transport numerical model of the target object is used to at least reflect the distribution of the target object inside the single crystal furnace under different process conditions and magnetic field structures; generating a plurality of characteristic parameters corresponding to the target object under a plurality of process conditions and a plurality of magnetic field structure parameters according to the transport numerical model of the target object, where the characteristic parameters are used to characterize the physical properties of the target object; and screening target process conditions and target magnetic field structure parameters from the plurality of process conditions and the plurality of magnetic field structure parameters according to the plurality of characteristic parameters, so as to control the single crystal pulling process of the single crystal furnace under the target process conditions and the target magnetic field structure parameters.

[0080] Obviously, those skilled in the art should understand that the above-mentioned modules or steps of the present invention can be implemented by a general-purpose computing device. They can be centralized on a single computing device or distributed on a network composed of a plurality of computing devices. They can be implemented by program codes executable by the computing device, so that they can be stored in a storage device and executed by the computing device. And in some cases, the steps shown or described herein can be executed in a different order, or they can be separately fabricated into individual integrated circuit modules, or multiple modules or steps among them can be fabricated into a single integrated circuit module to implement. Thus, the present invention is not limited to any specific combination of hardware and software.

[0081] Those skilled in the art should understand that the embodiments of the present application can be provided as a method, a system, or a computer program product. Therefore, the present application can take the form of a complete hardware embodiment, a complete software embodiment, or an embodiment combining software and hardware aspects. Moreover, the present application can take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk memories, CD-ROMs, optical memories, etc.) containing computer-usable program codes.

[0082] The present application is described with reference to the flowcharts and / or block diagrams of methods, apparatuses (systems), and computer program products according to embodiments of the present application. It should be understood that each flow and / or block in the flowcharts and / or block diagrams, and the combination of flows and / or blocks in the flowcharts and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to the processors of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing devices to generate a machine, so that the instructions executed by the processors of the computer or other programmable data processing devices generate for implementing in the process Figure 1 one process or multiple processes and / or blocks Figure 1means for the functions specified in one or more blocks.

[0083] These computer program instructions may also be stored in a computer-readable memory that can direct a computer or other programmable data processing apparatus to function in a particular manner, such that the instructions stored in the computer-readable memory produce a manufacture including an instruction means that implements the functions specified in one Figure 1 one or more processes and / or blocks Figure 1 means for the functions specified in one or more blocks.

[0084] These computer program instructions may also be loaded onto a computer or other programmable data processing apparatus, such that a series of operational steps are performed on the computer or other programmable apparatus to produce a computer-implemented process, whereby the instructions executed on the computer or other programmable apparatus provide steps for implementing the functions specified in one Figure 1 one or more processes and / or blocks Figure 1 means for the functions specified in one or more blocks.

[0085] In a typical configuration, a computing device includes one or more processors (CPUs), an input / output interface, a network interface, and memory.

[0086] The memory may include non-permanent memory in the form of computer-readable media, random access memory (RAM) and / or non-volatile memory, such as read-only memory (ROM) or flash memory (flash RAM). The memory is an example of computer-readable media.

[0087] Computer-readable media includes both permanent and non-permanent, removable and non-removable media implemented by any method or technology for storing information. The information can be computer-readable instructions, data structures, program modules, or other data. Examples of computer storage media include, but are not limited to, phase change memory (PRAM), static random access memory (SRAM), dynamic random access memory (DRAM), other types of random access memory (RAM), read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), flash memory or other memory technologies, compact disc read-only memory (CD-ROM), digital versatile discs (DVD) or other optical storage, magnetic cassettes, magnetic tape disk storage or other magnetic storage devices, or any other non-transmission media that can be used to store information accessible by a computing device. As defined herein, computer-readable media does not include transitory media such as modulated data signals and carrier waves.

[0088] It should also be noted that the term "comprising", "including" or any other variant thereof is intended to cover non-exclusive inclusion, such that a process, method, commodity or device comprising a series of elements not only includes those elements but also includes other elements not expressly listed, or elements inherent to such process, method, commodity or device. Without further limitation, an element defined by the statement "comprising an..." does not exclude the presence of additional identical elements in the process, method, commodity or device comprising the element.

[0089] From the above description, it can be seen that the above embodiments of the present application achieve the following technical effects:

[0090] 1) In the control method of the crystal pulling process of the embodiments of the present application, a transport numerical model of target objects such as oxygen impurities and phosphorus dopants is established to at least reflect the distribution of the target objects inside the single crystal furnace under different process conditions and magnetic field structures. Based on the above transport numerical model, the physical properties of the target objects in the melt and crystal during different stages of single crystal silicon growth under different process conditions and magnetic field structures are studied, so as to develop a transport regulation technology for target objects such as oxygen impurities and phosphorus dopants in the magnetic-controlled N-type single crystal silicon pulling growth. Furthermore, through process parameter optimization and magnetic field structure matching, not only can the reduction and uniform distribution of oxygen impurity concentration in the crystal be achieved to reduce the attenuation rate of minority carrier lifetime during the crystal growth process, which is beneficial to improving the efficiency of photovoltaic cells, but also the distribution uniformity of phosphorus in N-type single crystal silicon can be improved to improve the resistivity uniformity of N-type single crystal silicon and slow down or avoid the fluctuation and attenuation of minority carrier lifetime during the crystal growth process.

[0091] 2) The embodiments of the present application can verify whether the adjusted magnetic field structure parameters and process conditions can indeed improve the distribution uniformity of target objects such as oxygen impurities and phosphorus elements in N-type single crystal silicon through continuous production data collection and analysis.

[0092] 3) The embodiments of the present application can effectively utilize the hook-shaped magnetic field to improve the distribution uniformity of target objects such as oxygen impurities and phosphorus elements in N-type single crystal silicon, reduce the influence of uneven distribution on the minority carrier lifetime during the crystal growth process, and is beneficial to improving the efficiency of photovoltaic cells.

[0093] The above are only the preferred embodiments of the present application and are not used to limit the present application. For those skilled in the art, the present application can have various changes and modifications. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included within the protection scope of the present application.

Claims

1. A control method for a crystal pulling process, characterized in that: include: Constructing a transport numerical model of a target object in a single crystal furnace, wherein the transport numerical model of the target object is used to at least reflect the distribution of the target object inside the single crystal furnace under different process conditions and magnetic field structures; Calculation is performed according to the transport numerical model of the target object to obtain calculation results corresponding to multiple melt systems, wherein the calculation results include a dynamic relationship between an input set and an output set of the transport numerical model, and the dynamic relationship is used to reflect the physical properties corresponding to the multiple melt systems, and any two of the melt systems have different dynamic properties. The multiple melt systems correspond to multiple process conditions and multiple magnetic field structure parameters, respectively, wherein: In the case where the target object includes oxygen impurities, the physical properties include at least one of the following: occurrence characteristics of oxygen impurities in raw materials, dissolution characteristics of oxygen impurities on the crucible wall, transport characteristics of oxygen impurities in the silicon melt, segregation characteristics of oxygen impurities at the crystal interface, evaporation characteristics of oxygen impurities on the melt surface, and distribution laws of oxygen impurities along the radial and axial directions of the crystal; In the case where the target object includes a phosphorus dopant, the physical property includes at least one of the following: a transport property of the phosphorus dopant in a silicon melt, a segregation property of the phosphorus dopant at a crystal interface, an evaporation property of the phosphorus dopant on a silicon melt surface, and a distribution law of the phosphorus dopant along a radial direction and an axial direction of the crystal; Determining a plurality of characteristic parameters corresponding to the plurality of melt systems respectively according to the calculation results, a plurality of preset process conditions and a plurality of preset magnetic field structure parameters; According to the multiple characteristic parameters, target process conditions and target magnetic field structure parameters are screened from the multiple process conditions and the multiple magnetic field structure parameters to control the single crystal furnace to perform a crystal pulling process under the target process conditions and the target magnetic field structure parameters.

2. The control method according to claim 1, characterized in that: The target object includes oxygen impurities, and the construction of a transport numerical model of the target object in the single crystal furnace includes: According to a plurality of first historical experimental data under a plurality of process conditions and a plurality of magnetic field structure parameters and non-equilibrium molecular dynamics theory, a first theoretical relationship of the oxygen dissolution rate at the contact surface between the crucible and the silicon melt in the single crystal furnace under different process conditions and magnetic field structures is established, wherein the plurality of first historical experimental data include: the oxygen dissolution rate in the single crystal furnace and the oxygen concentration in the single crystal furnace; According to the first theoretical relationship, a transport numerical model of the oxygen impurities is constructed.

3. The control method according to claim 1, characterized in that: The target object includes a phosphorus dopant, and the step of constructing a transport numerical model of the target object in the single crystal furnace includes: A transport numerical model of the phosphorus dopant is constructed based on multiple second historical experimental data under multiple process conditions and multiple magnetic field structure parameters, wherein the multiple second historical experimental data include: the phosphorus dopant concentration in the single crystal furnace, and the resistivity of the single crystal silicon prepared by the single crystal furnace.

4. The control method according to claim 1, characterized in that: Determining a plurality of characteristic parameters corresponding to a plurality of melt systems according to the calculation results, a plurality of preset process conditions and a plurality of preset magnetic field structure parameters includes: According to the calculation results, multiple preset rotational speeds and multiple preset hook-shaped magnetic field structure parameters, characteristic parameters corresponding to multiple melt systems are obtained, wherein the preset rotational speed includes at least: the crucible rotational speed of the single crystal furnace, and the crystal rotational speed of the single crystal furnace, the preset hook-shaped magnetic field structure parameters include at least: the position and intensity of the hook-shaped magnetic field, and the characteristic parameters include at least one of the following: the concentration distribution of the oxygen impurities, the crystal growth rate in the single crystal furnace, and the temperature distribution in the single crystal furnace.

5. The control method according to any one of claims 1 to 4, characterized in that: The step of selecting target process conditions and target magnetic field structure parameters from the plurality of process conditions and the plurality of magnetic field structure parameters according to the plurality of characteristic parameters comprises: Determining whether the plurality of characteristic parameters meet corresponding preset conditions; When a first target characteristic parameter among the plurality of characteristic parameters satisfies a target preset condition, the process conditions and the magnetic field structure parameters corresponding to the first target characteristic parameter are determined as target process conditions and target magnetic field structure parameters.

6. The control method according to claim 5, characterized in that: Also includes: Adjustment step: when the first target characteristic parameter does not meet the target preset condition, output an adjustment signal to the single crystal furnace to adjust the process conditions and the magnetic field structure parameters corresponding to the first target characteristic parameter; Determining step: re-determining updated first target characteristic parameters corresponding to the target object under the adjusted process conditions and / or magnetic field structure parameters according to the transport numerical model of the target object; Determination step: determining whether the first target characteristic parameter meets the target preset condition; In the case that the first target characteristic parameter does not satisfy the target preset condition, the adjusting step, the determining step and the judging step are repeatedly performed until the first target characteristic parameter satisfies the target preset condition and then stops.

7. The control method according to claim 6, characterized in that: When the single crystal furnace receives the adjustment signal, the single crystal silicon growth is performed using the adjusted process conditions and / or magnetic field structure parameters, and the determining step includes: generating, according to the transport numerical model of the target object, a second target characteristic parameter corresponding to the target object under the adjusted process conditions and / or magnetic field structure parameters, wherein the second target characteristic parameter is a characteristic parameter different from the first target characteristic parameter among the plurality of characteristic parameters; Acquiring target experimental data of the single crystal silicon growth, wherein the target experimental data and the second target characteristic parameter have the same characteristic type; Determine whether the difference between the second target characteristic parameter and the experimental data satisfies a preset difference; When the preset difference is met, the second target characteristic parameter is determined as the updated first target characteristic parameter.

8. A process control device for a single crystal silicon rod, characterized in that: include: A construction module, used to construct a transport numerical model of a target object in a single crystal furnace, wherein the target object includes at least one of an oxygen impurity and a phosphorus dopant, wherein the transport numerical model of the target object is used to at least reflect the distribution of the target object inside the single crystal furnace under different process conditions and magnetic field structures; A generating module, configured to generate, according to a transport numerical model of the target object, a plurality of characteristic parameters corresponding to the target object under a plurality of process conditions and a plurality of magnetic field structure parameters, wherein the characteristic parameters are used to characterize the physical properties of the target object; a control module, for selecting target process conditions and target magnetic field structure parameters from the plurality of process conditions and the plurality of magnetic field structure parameters according to the plurality of characteristic parameters, so as to control the single crystal furnace to perform a crystal pulling process under the target process conditions and the target magnetic field structure parameters, The generation module comprises: A calculation submodule is used to perform calculations according to the transport numerical model of the target object to obtain calculation results corresponding to multiple melt systems, wherein the calculation results include a dynamic relationship between an input set and an output set of the transport numerical model, and the dynamic relationship is used to reflect the physical properties corresponding to the multiple melt systems, any two of the melt systems have different dynamic properties, and the multiple melt systems correspond to multiple process conditions and multiple magnetic field structure parameters, respectively, wherein: In the case where the target object includes oxygen impurities, the physical properties include at least one of the following: occurrence characteristics of oxygen impurities in raw materials, dissolution characteristics of oxygen impurities on the crucible wall, transport characteristics of oxygen impurities in the silicon melt, segregation characteristics of oxygen impurities at the crystal interface, evaporation characteristics of oxygen impurities on the melt surface, and distribution laws of oxygen impurities along the radial and axial directions of the crystal; In the case where the target object includes a phosphorus dopant, the physical property includes at least one of the following: a transport property of the phosphorus dopant in a silicon melt, a segregation property of the phosphorus dopant at a crystal interface, an evaporation property of the phosphorus dopant on a silicon melt surface, and a distribution law of the phosphorus dopant along a radial direction and an axial direction of the crystal; The first determination submodule is used to determine a plurality of characteristic parameters corresponding to the plurality of melt systems respectively according to the calculation results, a plurality of preset process conditions and a plurality of preset magnetic field structure parameters.

9. A crystal pulling system, characterized in that: include: A single crystal furnace, one or more processors, a memory, and one or more programs, wherein the one or more processors are electrically connected to the single crystal furnace, the one or more programs are stored in the memory and are configured to be executed by the one or more processors, and the one or more programs include a control method for executing the crystal pulling process described in any one of claims 1 to 7.

Images