Monocrystalline silicon resistivity regulation and control method, system and program product

Abstract

The invention discloses a method, a system and a program product for regulating and controlling resistivity of monocrystalline silicon. The method comprises the following steps: acquiring the resistivity measured value of the head part and the resistivity measured value of the tail part of a current section of a silicon single crystal rod, and the temperature value of each resistivity measured value corresponding to a measurement point at a measurement moment; determining a corresponding resistivity compensation value according to the single resistivity measured value and the corresponding temperature value, and adding the resistivity compensation value and the corresponding resistivity measured value to obtain a corresponding resistivity correction value; according to the resistivity correction value of the head of the current section of the monocrystalline silicon rod, the resistivity correction value of the tail of the current section of the monocrystalline silicon rod and the expected resistivity, a dopant putting scheme of silicon liquid during drawing of a second section of the monocrystalline silicon rod after the current section of the monocrystalline silicon rod is determined, and the dopant putting scheme comprises the mass of a first dopant and the mass of a second dopant, the volatility of the first dopant is greater than that of the second dopant, and the first dopant and the second dopant have the same doping type. Monocrystalline silicon resistivity regulation and control are accurate, and response is timely.

Description

Technical Field

[0001] This invention relates to a method, system, and program product for controlling the resistivity of monocrystalline silicon. Background Technology

[0002] In existing technologies, after a monocrystalline silicon rod is pulled, it is cut into multiple segments, and the resistivity at both ends of each monocrystalline silicon segment is measured. The process parameters are adjusted based on the difference between the measured resistivity and the expected value, so that the resistivity of the final monocrystalline silicon rod is uniform and close to the expected value.

[0003] The inventors discovered that existing technologies neglect the influence of temperature on resistivity measurement and that resistivity control methods are not precise enough. Summary of the Invention

[0004] This invention provides a method, system, and program product for controlling the resistivity of monocrystalline silicon, so as to achieve fine control of the resistivity of monocrystalline silicon rods.

[0005] This invention provides the following technical solution: a method for controlling the resistivity of single-crystal silicon, comprising:

[0006] Obtain the measured resistivity values ​​at the head and tail of the current segment of the single crystal silicon rod, as well as the temperature values ​​at the corresponding measurement points at the measurement times corresponding to each measured resistivity value.

[0007] The corresponding resistivity compensation value is determined based on a single measured resistivity value and its corresponding temperature value. The resistivity compensation value is then added to the corresponding measured resistivity value to obtain the corresponding resistivity correction value.

[0008] Based on the resistivity correction value at the head of the current segment of the single crystal silicon rod, the resistivity correction value at the tail, and the expected resistivity, the dopant doping scheme for the silicon melt during the pulling of the second segment of the single crystal silicon rod after the current segment is determined. The dopant doping scheme includes the mass of a first dopant and a second dopant, wherein the volatility of the first dopant is greater than that of the second dopant and the two doping types are the same.

[0009] In some embodiments, the resistivity correction value is determined according to the following method:

[0010] A table is provided to correspond to the resistivity compensation value with the numerical range of temperature value and resistivity correction value. The table describes the resistivity compensation value corresponding to different temperature values ​​when the resistivity correction value is in different numerical ranges. The values ​​in the table are empirical values.

[0011] According to the correspondence table, multiple resistivity compensation values ​​corresponding to the temperature value are retrieved. The retrieved resistivity compensation values ​​are added to the measured resistivity value. If the sum is within the resistivity correction value range corresponding to the resistivity compensation value, the sum is determined as the resistivity correction value.

[0012] In some embodiments, the dopant delivery scheme for the silicon melt during the pulling of the second segment of the single-crystal silicon rod is determined based on the resistivity correction value at the head and tail of the current segment of the single-crystal silicon rod and the expected resistivity, including:

[0013] If the ratio of the resistivity correction value at the head to the resistivity correction value at the tail of the current monocrystalline silicon rod is greater than a first proportional threshold, the first proportional threshold is greater than 1, and the resistivity at the head of the current monocrystalline silicon rod is greater than the expected resistivity, the following operations are performed:

[0014] The resistivity correction value of the current segment of the single crystal silicon rod head and the expected resistivity are respectively mapped to carrier concentration. Assuming that the amount of silicon material added to the current segment and the second segment after the current segment are equal, the adjustment amount of the first dopant relative to the current segment is determined according to the difference in carrier concentration between the two segments, so that the expected resistivity of the single crystal silicon rod head during the production of the second segment after the current segment is the target resistivity.

[0015] The adjustment increment of the first dopant is corrected according to the volatility ratio to determine the amount of the first dopant to be added, wherein the amount of the second dopant to be added is equal to the amount of the second dopant to be added in the current segment.

[0016] Based on the actual amount of silicon added in the second segment after the current segment and the amount of silicon added in the current segment, the amounts of the first and second dopant are scaled proportionally to obtain the doping scheme for the second segment after the current segment.

[0017] In some embodiments, the dopant delivery scheme for the silicon melt during the pulling of the second segment of the single-crystal silicon rod is determined based on the resistivity correction value at the head and tail of the current segment of the single-crystal silicon rod and the expected resistivity, including:

[0018] If the ratio of the resistivity correction value at the head to the resistivity correction value at the tail of the current monocrystalline silicon rod is less than a second proportional threshold, the second proportional threshold is less than 1, and the resistivity at the head of the current monocrystalline silicon rod is less than the expected resistivity, the following operations are performed:

[0019] The resistivity correction value of the current segment of the single crystal silicon rod head and the expected resistivity are respectively mapped to carrier concentration. Assuming that the amount of silicon material added to the current segment and the second segment after the current segment are equal, the reduction amount of the first dopant relative to the current segment is determined according to the difference in carrier concentration between the two segments, so that the expected resistivity of the single crystal silicon rod head during the production of the second segment after the current segment is the target resistivity.

[0020] The amount of the first dopant is adjusted according to the volatility ratio to determine the amount of the first dopant to be added, wherein the amount of the second dopant to be added is equal to the amount of the second dopant to be added in the current segment.

[0021] Based on the actual amount of silicon added in the second segment after the current segment and the amount of silicon added in the current segment, the amounts of the first and second dopant are scaled proportionally to obtain the doping scheme for the second segment after the current segment.

[0022] In some embodiments, the dopant delivery scheme for the silicon melt during the pulling of the second segment of the single-crystal silicon rod is determined based on the resistivity correction value at the head and tail of the current segment of the single-crystal silicon rod and the expected resistivity, including:

[0023] If the absolute value of the difference between the ratio of the resistivity correction value at the head of the current segment of the monocrystalline silicon rod to the resistivity correction value at the tail and 1 is less than a third proportional threshold, and the absolute value of the difference between the resistivity correction value at the head of the current segment of the monocrystalline silicon rod and the expected resistivity is greater than a set threshold, the following operations are performed:

[0024] The resistivity correction value of the current segment of the single crystal silicon rod head and the expected resistivity are respectively mapped to carrier concentration. Assuming that the amount of silicon material added to the current segment and the second segment after the current segment are equal, the increase or decrease of the first dopant and the second dopant relative to the current segment is determined according to the difference in carrier concentration between the two segments during the production of the second segment after the current segment, so that the expected resistivity of the single crystal silicon rod head during the production of the second segment after the current segment is the target resistivity, wherein the mass ratio of the first dopant to the second dopant remains unchanged.

[0025] Based on the actual amount of silicon added in the second segment after the current segment and the amount of silicon added in the current segment, the amounts of the first and second dopant are scaled proportionally to obtain the doping scheme for the second segment after the current segment.

[0026] In some implementations, the method further includes prompting production personnel to investigate the cause of the fault if the ratio of the resistivity correction value at the head to the resistivity correction value at the tail of the current segment of the monocrystalline silicon rod is found to fluctuate abnormally.

[0027] This invention provides the following technical solution: a single-crystal silicon resistivity control system, including an electronic device, the electronic device comprising: a processor and a memory; the processor and the memory cooperate with each other to enable the electronic device to execute the above-described method.

[0028] In some implementations, resistivity measuring instruments and temperature measuring instruments are also included.

[0029] In some embodiments, the electronic device runs production execution system software, which performs the methods described above.

[0030] The present invention provides the following technical solution: a program product, which executes the above-described method during runtime.

[0031] The solution of this invention can be applied to the production scenario of continuous pulling of monocrystalline silicon rods, quickly obtaining the resistivity correction values ​​of the head and tail of the monocrystalline silicon rod (that is, the resistivity corresponding to the national standard at 23°C), without waiting for the monocrystalline silicon rod to cool to room temperature. Based on the degree of difference between the resistivity correction values ​​of the head and tail of the monocrystalline silicon rod and the degree of difference between the resistivity correction value of the head of the monocrystalline silicon rod and the expected resistivity, the ratio and amount of the first dopant and the second dopant are adjusted, so that the resistivity of the monocrystalline silicon rod is uniformly distributed along the axial direction and the deviation from the expected resistivity is minimized during subsequent pulling of the monocrystalline silicon rod. Attached Figure Description

[0032] Figure 1 This is a schematic flowchart of the method for controlling the resistivity of monocrystalline silicon according to the present invention.

[0033] Figure 2 This is a schematic diagram of the electronic device in the monocrystalline silicon resistivity control system of the present invention. Detailed Implementation

[0034] The present invention will be further described below with reference to specific embodiments, but the scope of protection of the present invention is not limited thereto.

[0035] refer to Figure 1 The present invention provides a method for controlling the resistivity of monocrystalline silicon, which includes the following steps.

[0036] Step S1: Obtain the measured resistivity value of the head of the current segment of the single crystal silicon rod, the measured resistivity value of the tail, and the temperature value of the measurement point corresponding to the measurement time of each measured resistivity value.

[0037] Specifically, after the current segment of the monocrystalline silicon rod is pulled, it is transferred to a cutting machine to be cut into multiple monocrystalline silicon segments. For example, the monocrystalline silicon rod is cut into 3, 4, or 5 monocrystalline silicon segments. Subsequently, the resistivity at the end of each monocrystalline silicon segment and the temperature at the corresponding location are measured simultaneously.

[0038] Specifically, a minority carrier lifetime meter and a temperature gun can be used to simultaneously detect the resistivity and temperature at the same cross section of a monocrystalline silicon segment.

[0039] Note: In the continuous production process of monocrystalline silicon rods, the pulling process of a single monocrystalline silicon rod is called a "segment".

[0040] Under normal circumstances, the resistivity of a single-crystal silicon rod changes continuously and monotonically along the axial direction.

[0041] In one implementation, resistivity and temperature are simultaneously measured at multiple points on two cross-sections of the monocrystalline silicon segment at the head position to obtain the measured resistivity value and the corresponding temperature value of the monocrystalline silicon rod head. For example, resistivity and temperature are simultaneously measured at five points on five cross-sections of the monocrystalline silicon segment at the head position to obtain five data pairs of measured resistivity values ​​and corresponding temperature values ​​for the monocrystalline silicon rod head.

[0042] Resistivity and temperature are simultaneously measured at multiple points on two cross-sections of the monocrystalline silicon segment located at the tail end, yielding the measured resistivity and corresponding temperature values ​​at the tail end of the monocrystalline silicon rod. For example, resistivity and temperature are simultaneously measured at five points on five cross-sections of the monocrystalline silicon segment at the tail end, resulting in five pairs of data for the measured resistivity and corresponding temperature values ​​at the tail end of the monocrystalline silicon rod.

[0043] In some implementations, the data collected by the minority carrier lifetime meter and the temperature gun are transmitted to the Manufacturing Execution System (MES), or the data collected by the minority carrier lifetime meter and the temperature gun are entered into the MES by the staff.

[0044] Step S2: Determine the corresponding resistivity compensation value based on the individual measured resistivity value and its corresponding temperature value, and add the resistivity compensation value to the corresponding measured resistivity value to obtain the corresponding resistivity correction value.

[0045] The inventors discovered that the relationship, or trend, between resistivity compensation and temperature differs depending on the resistivity correction value's range. Therefore, it is necessary to divide the resistivity correction value into different ranges and handle them accordingly.

[0046] In some implementations, the resistivity correction value is divided into numerical ranges with a length of 0.1 Ω·cm.

[0047] The national standard for resistivity of monocrystalline silicon specifically refers to the resistivity at 23°C. Therefore, the resistivity correction value in this invention specifically refers to the resistivity calculated by correcting the measured resistivity value to reflect the resistivity at 23°C.

[0048] Within each range of resistivity correction values, the correspondence between resistivity compensation values ​​and temperature is an empirical correspondence derived from historical data. For example, for the same point in the same monocrystalline silicon segment, resistivity is measured at different temperatures, and the difference between the measured resistance value at 23℃ and the measured resistivity values ​​at each temperature is calculated. This yields the resistivity compensation value at different temperatures when the measured resistivity value falls within a certain range.

[0049] The table below shows the correspondence between the resistivity compensation value and the numerical range of the temperature and resistivity correction values, which the inventors summarized based on actual production data for the same type of single-crystal silicon rod.

[0050]

[0051] The table above only shows a limited range of resistivity correction values.

[0052] Once the measured resistivity and temperature values ​​of a measurement point in a monocrystalline silicon segment are obtained, several optional compensation values ​​corresponding to that temperature value are searched. If the resistivity correction value obtained by adding the measured resistivity value and the resistivity compensation value falls within the range of the resistivity correction value corresponding to the resistivity compensation value, then the resistivity correction value is adopted.

[0053] For example, suppose the resistivity at a certain measurement point is 0.62 Ω·cm, and the temperature at that point is 15℃. The resistivity compensation values ​​corresponding to 15℃ are 0.05 Ω·cm, 0.09 Ω·cm, 0.06 Ω·cm, and 0.07 Ω·cm, respectively. 0.62 + 0.05 = 0.67. Referring to the table, 0.67 Ω·cm falls within the resistivity correction range of 0.6 to 0.7 Ω·cm, and the compensation value for this range at 15℃ is 0.05, which meets the table requirements. Therefore, the final resistivity correction value for this point at 23℃ is determined to be 0.67 Ω·cm.

[0054] Step S3: Determine the dopant doping scheme for the silicon melt during the pulling of the second single crystal silicon rod after the current single crystal silicon rod based on the resistivity correction value of the head and tail of the current single crystal silicon rod and the expected resistivity. The dopant doping scheme includes the mass of the first dopant and the second dopant. The volatility of the first dopant is greater than that of the second dopant and the two doping types are the same.

[0055] When there are multiple resistivity measurement points at the head, the resistivity correction values ​​at each point can be averaged to obtain the resistivity correction value for the head section below. Similarly, the resistivity correction value for the tail section below can be the average of the resistivity correction values ​​at each measurement point at the tail section.

[0056] This invention does not limit the specific selection of the two dopants, as long as they are both N-type or both P-type and have different volatility.

[0057] The first dopant is, for example, pure antimony, and the second dopant is, for example, a silicon-phosphorus alloy. Antimony is more volatile than silicon-phosphorus alloy. This will be used as an example in the following explanation. Both the first and second dopants are added to the single-crystal furnace along with the silicon material during the melting stage, and under normal continuous production conditions, no further dopant replenishment is required during the single-crystal silicon pulling process.

[0058] This invention applies to the RCZ (Czochralski) method, which involves measuring the resistivity of the head and tail of a single-crystal silicon rod after the first section is pulled. At the same time, the second section of the single-crystal silicon rod is being pulled, and the quality or ratio of the dopant is adjusted during the pulling of the third section.

[0059] The inventors discovered four common types of defects, or four problems, in production. The following describes how to handle these four common defects.

[0060] Type 1 of Defect: The ratio of the resistivity correction value at the head of the current segment of the monocrystalline silicon rod to the resistivity correction value at the tail is greater than a first proportional threshold, the first proportional threshold is greater than 1, and the resistivity at the head of the current segment of the monocrystalline silicon rod is greater than the expected resistivity.

[0061] The inventors analyzed that the cause of the defect was a severe lack of antimony concentration. The tail volatilization effect led to a significant reduction in antimony concentration, which in turn caused a significant axial decrease in resistivity along the direction from head to tail.

[0062] The inventor devised a strategy to maintain the current amount of silicon-phosphorus alloy added while increasing the amount of antimony added.

[0063] The following numerical examples illustrate how much more antimony needs to be added.

[0064] The current resistivity correction value for the head of the monocrystalline silicon rod is 1.10 Ω·cm, and the resistivity correction value for the tail is 1.43 Ω·cm. The target resistivity is 1.03 Ω·cm, and the first proportional threshold is set to 1.2. The ratio of the tail resistivity correction value to the head resistivity correction value is 1.3, which is greater than the first proportional threshold. The first proportional threshold can also be other appropriate values, such as 1.25, 1.15, etc. The first proportional threshold is a preset value adjusted according to production needs, representing the maximum allowable difference in resistivity between the head and tail; a value greater than 1.1 is recommended.

[0065] The adjustment steps are as follows.

[0066] S311. Map the resistivity correction value of the current segment of the single crystal silicon rod head and the expected resistivity to carrier concentration respectively. Assuming that the amount of silicon material added to the current segment and the second segment after the current segment are equal, determine the adjustment amount of the first dopant relative to the current segment during the production of the second segment after the current segment based on the difference in carrier concentration between the two segments, so that the expected resistivity of the single crystal silicon rod head during the production of the second segment after the current segment is the target resistivity.

[0067] Specifically, based on the conversion relationship between carrier concentration and resistivity specified in national standards (e.g., referring to GB / T13389-2014), the target resistivity and the corrected resistivity value at the head of the single-crystal silicon rod are mapped to carrier concentrations, and the difference between the two carrier concentrations is calculated. The carrier concentration corresponding to the target resistivity of 1.03 Ω·cm is 4.66972e+15cm. -3 The carrier concentration corresponding to the resistivity correction value at the head of the single-crystal silicon rod is 4.35 × 10⁴ e⁺¹⁵ cm⁻¹. -3 The carrier concentration difference between the two is 3.1868e+14cm. -3 .

[0068] Multiplying the difference in carrier concentration between the two by the known volume of molten silicon in the single-crystal furnace before the current stage of single-crystal silicon pulling yields the carrier atomic adjustment increment. The known volume of molten silicon is 275590.55 cm³. 3 The atomic number adjustment increment of the charge carriers is obtained as N1=N×V=(3.18679×10^14)×275590.55=8.782492088345e+19, where N represents the above-mentioned charge carrier concentration difference, V represents the volume of silicon liquid, and N1 is the number of atoms.

[0069] The carrier atomic number modulation increment is converted into the mass modulation increment M1 of the first dopant. M1 = (N1 * M) / NA = (8.782492088345e + 19 * 121.76) / 6.0221367 × 10 23 ≈0.018g, where M is the relative mass of antimony and NA is Avogadro's constant.

[0070] S312. The adjustment increment of the first dopant is corrected according to the volatility ratio to determine the amount of the first dopant to be added, wherein the amount of the second dopant to be added is equal to the amount of the second dopant to be added in the current segment.

[0071] In some implementations, the volatilization ratio is determined based on historical production data from the current single-crystal furnace. For example, during the pulling of single-crystal silicon in the current stage, the difference between the theoretically calculated required weight of antimony (e.g., 11g) and the weight of antimony corresponding to the actual produced head resistivity (1.10Ω·cm) (e.g., 7.45g) / theoretically calculated required weight of antimony (11g) = volatilization ratio = (11-7.45) / 11*100% ≈ 32.27%.

[0072] When pulling the second single-crystal silicon after the first segment, the required amount of antimony adjustment is (1 + 32.27%) * 0.018 = 0.024g.

[0073] The volatile ratio can also be an empirical value, i.e., a fixed value.

[0074] The amounts of antimony and phosphorus silicon added in the current segment are known. By increasing the amount of antimony added by 0.024g while keeping the amount of phosphorus silicon added unchanged, a preliminary solution for the doping scheme of the second segment after the current segment is obtained.

[0075] S313. Based on the actual amount of silicon material added in the second segment after the current segment and the amount of silicon material added in the current segment, the amount of the first dopant and the second dopant are proportionally scaled to obtain the doping scheme for the second segment after the current segment.

[0076] The above calculations assume that the amount of silicon material added in the current segment is equal to that in the second segment following the current segment.

[0077] If the amount of silicon added in the current segment is S1, and the amount of silicon added in the second segment after the current segment is S2, and the amount of the first dopant added in the preliminary solution of the doping scheme for the second segment after the current segment is C1 and the amount of the second dopant added is C2, then in the second segment after the current segment, the amount of the first dopant added is C1*S2 / S1 and the amount of the second dopant added is C2*S2 / S1.

[0078] Note: In the above calculations, the residual silicon liquid and dopants in the residual silicon liquid that were already in the single crystal furnace before the addition of silicon material in the current segment and the second segment are ignored.

[0079] Defect Type 2: The ratio of the resistivity correction value at the head of the current segment of the monocrystalline silicon rod to the resistivity correction value at the tail is less than a second proportional threshold, where the second proportional threshold is less than 1, and the resistivity at the head of the current segment of the monocrystalline silicon rod is less than the expected resistivity. The second proportional threshold is, for example, 0.9, 0.95, 0.85, etc., with a typical value of 0.9.

[0080] The cause of the defect was determined to be excessive antimony concentration.

[0081] Adjust the strategy to keep the current amount of silicon-phosphorus alloy added unchanged, but reduce the amount of antimony added.

[0082] S321. Map the resistivity correction value of the current segment of the monocrystalline silicon rod head and the expected resistivity to carrier concentration respectively. Assuming that the amount of silicon material added to the current segment and the second segment after the current segment are equal, determine the reduction amount of the first dopant relative to the current segment during the production of the second segment after the current segment based on the difference in carrier concentration between the two segments, so that the expected resistivity of the monocrystalline silicon rod head during the production of the second segment after the current segment is the target resistivity.

[0083] The calculation process is as described in S311.

[0084] S322. Adjust the reduction amount of the first dopant according to the volatility ratio to determine the amount of the first dopant to be added, wherein the amount of the second dopant to be added is equal to the amount of the second dopant to be added in the current segment.

[0085] The actual reduction amount of the first dopant = (1 + volatility ratio) * the reduction amount of the first dopant calculated in step S321. The calculation process is the same as in S312.

[0086] S323. Based on the actual amount of silicon material added in the second segment after the current segment and the amount of silicon material added in the current segment, the amount of the first dopant and the second dopant are proportionally scaled to obtain the doping scheme for the second segment after the current segment.

[0087] The calculation process can be found in S313.

[0088] Type 3 Defect: The absolute value of the difference between the ratio of the resistivity correction value at the head of the current monocrystalline silicon rod and the resistivity correction value at the tail, and 1, is less than the third proportional threshold, and the absolute value of the difference between the resistivity correction value at the head of the current monocrystalline silicon rod and the expected resistivity is greater than the set threshold. In other words, the ratio of head to tail resistivity is close to 1, but the absolute value deviates from the target resistivity. The third proportional threshold is, for example, a value close to 0, such as 0.01, 0.02, or 0.05. The set threshold is, for example, an appropriate value such as 0.02 Ω·cm, 0.05 Ω·cm, or 0.1 Ω·cm. The third proportional threshold is an empirical or set value, serving as a criterion for judging whether the head and tail resistivities are sufficiently close. It is recommended that the third proportional threshold be set less than or equal to 0.1.

[0089] The inventor analyzed the cause as follows: the total amount of dopant was improperly set.

[0090] Adjustment strategy: Adjust the total amount of phosphorus-silicon alloy and antimony year-on-year, keeping their relative proportions unchanged.

[0091] For example, the judgment criteria are that the ratio of the head and tail resistivity is within the numerical range [0.95, 1.05], and the absolute value of the difference between the head resistivity and the target resistivity is greater than 0.1 Ω·cm, then it is judged as defect type three.

[0092] The adjustment steps are as follows.

[0093] S331. Map the resistivity correction value of the current segment of the single crystal silicon rod head and the expected resistivity to carrier concentration respectively. Assuming that the amount of silicon material added to the current segment and the second segment after the current segment are equal, determine the increase or decrease of the first dopant and the second dopant relative to the current segment during the production of the second segment after the current segment based on the difference in carrier concentration between the two segments, so that the expected resistivity of the single crystal silicon rod head during the production of the second segment after the current segment is the target resistivity, wherein the mass ratio of the first dopant to the second dopant remains unchanged.

[0094] S332. Based on the actual amount of silicon material added in the second segment after the current segment and the amount of silicon material added in the current segment, the amount of the first dopant and the second dopant are proportionally scaled to obtain the doping scheme for the second segment after the current segment.

[0095] Since the resistivity difference between the head and tail is small, there is no need to correct the increase or decrease, and it can be directly used as the increase or decrease of the first and second dopant in the next production.

[0096] Specifically, the resistivity correction value and target resistivity at the head of the single-crystal silicon rod are mapped to carrier concentration, and the carrier concentration difference between the two is calculated. This carrier concentration difference is then split into the concentration difference of the first dopant and the concentration difference of the second dopant according to the atomic ratio of the first dopant and the second dopant in the current doping scheme. The concentration difference of the first dopant is then mapped to the mass increase or decrease of the first dopant based on the silicon liquid volume, and the concentration difference of the second dopant is mapped to the mass increase or decrease of the second dopant. At this point, in the second segment following the current segment, the amount of first dopant and the amount of second dopant added are assumed to be equal to the amount of silicon added in the current segment. Referring to step S313, the amounts of first dopant and second dopant are scaled proportionally to obtain the doping scheme for the second segment following the current segment.

[0097] Type 4 Defect: Abnormal fluctuation in the ratio of head-to-tail resistivity correction values, i.e., a significant deviation from 1. The criterion for judging abnormal fluctuation is that the absolute value of the difference between the ratio of head-to-tail resistivity correction values ​​and 1 is greater than the fourth proportional threshold. Taking the fourth proportional threshold as 0.5 as an example, a ratio of head-to-tail resistivity correction values ​​>1.5 or <0.5 can be used as the criterion for judging abnormal fluctuation.

[0098] In this situation, suspend the adjustment of the doping formula and temporarily halt the pulling of single-crystal silicon in the second stage following the current stage. Production personnel are advised to investigate the following issues:

[0099] S341. Check the calibration status of the temperature measurement system.

[0100] S342. Check the purity and batch consistency of raw materials.

[0101] S342. Check the stability of crystal growth process parameters. Process parameters such as furnace pressure, operating power, and oxygen content all affect resistivity determination. The former two affect antimony volatilization, while the latter affects resistivity testing. Operating power refers to the heater power of the single crystal furnace, which requires high-temperature heating to melt the silicon material into a silicon solution before single crystal rods can be pulled. Oxygen content refers to the oxygen content at the tip of the single crystal silicon. Excessive oxygen content will result in an oxygen donor (negative charge) effect, leading to inaccurate resistivity measurements.

[0102] The inventors discovered that by using the above method for controlling the resistivity of monocrystalline silicon, the resistivity measurement is accurate, the resistivity control is accurate, and the resistivity control response is timely.

[0103] Based on the same inventive concept, embodiments of the present invention also provide a single-crystal silicon resistivity control system, including an electronic device, the electronic device comprising: a processor, a memory, and an interface; the processor, the memory, and the interface cooperate with each other to enable the electronic device to perform the above-described method.

[0104] In some implementations, the monocrystalline silicon resistivity control system further includes a resistivity measuring instrument and a temperature measuring instrument. The resistivity measuring instrument is used to measure the resistivity at the head and tail of the monocrystalline silicon rod, and the temperature measuring instrument is used to detect the current temperature at the measurement point of the resistivity measuring device.

[0105] Resistivity measuring instruments include, for example, minority carrier lifetime measuring instruments, and temperature measuring instruments include, for example, temperature guns.

[0106] In some embodiments, production execution system software runs in the electronic device, and the production execution system software performs the methods described above.

[0107] Figure 2 This is a schematic diagram of the structure of an electronic device provided in an embodiment of this application. Taking a personal computer (PC) as an example, the electronic device may include a processor 110, a memory 120, and a communication module 130, etc.

[0108] The processor 110 may include one or more processing units, and the memory 120 is used to store program code and data. In this embodiment of the invention, the processor 110 can execute computer execution instructions stored in the memory 120 for controlling and managing the operation of the electronic device.

[0109] The communication module 130 can be used for communication between various internal modules of an electronic device, or for communication between the electronic device and other external terminal devices. For example, if the electronic device communicates with other terminal devices via a wired connection, the communication module 130 may include an interface, such as a USB interface. The USB interface can be an interface conforming to the USB standard specification, specifically a Mini USB interface, a Micro USB interface, a USB Type-C interface, etc. The USB interface can be used to connect a charger to charge the electronic device, or it can be used to transfer data between the electronic device and peripheral devices.

[0110] Alternatively, the communication module 130 may include radio frequency circuits, Bluetooth chips, Wi-Fi chips, near-field communication (NFC) modules, etc., which can enable interaction between electronic devices and other terminal devices in a variety of different ways.

[0111] Optionally, the electronic device may also include a display screen 140, which can display a human-machine interface. The human-machine interface may, for example, allow the user to manually input resistivity and temperature values, and may also display the doping scheme for the second segment following the current segment.

[0112] Optionally, the electronic device may also include peripheral devices 150, such as a mouse, keyboard, speaker, microphone, etc.

[0113] It should be understood that, in addition to Figure 2 In addition to the various components or modules listed herein, the embodiments of this application do not specifically limit the structure of the electronic device. In other embodiments of this application, the electronic device may further include components that are more complex than those listed herein. Figure 2 More or fewer components, or combining some components, or splitting some components, or different component arrangements.

[0114] It should be noted that electronic devices can also be other hardware forms such as servers.

[0115] It should be noted that the processors mentioned above may include, but are not limited to, one or more processors or microprocessors. Each processor may be implemented as an Application Specific Integrated Circuit (ASIC), Digital Signal Processor (DSP), Digital Signal Processing Device (DSPD), Programmable Logic Device (PLD), Field Programmable Gate Array (FPGA), controller, microcontroller, microprocessor (MCU), central processing unit (CPU), graphics processing unit (GPU), or other electronic components to execute the methods in the above embodiments.

[0116] The above-mentioned storage devices can be USB flash drives, mechanical hard drives, solid-state drives, portable hard drives, read-only memory (ROM), random access memory (RAM), flash memory, EPROM memory, EEPROM memory, registers, magnetic disks or optical disks, and other media that can store program code.

[0117] Based on the same inventive concept, embodiments of the present invention also provide a program product that executes the above-described method for controlling the resistivity of monocrystalline silicon during operation.

[0118] The program product is, for example, a production execution system or a subsystem within a production execution system.

[0119] This invention is not limited to the above-described embodiments. Any modifications, improvements, or substitutions that can be conceived by those skilled in the art without departing from the essential content of this invention fall within the scope of this invention.

Claims

1. A method for controlling the resistivity of single-crystal silicon, characterized in that, include: Obtain the measured resistivity values ​​at the head and tail of the current segment of the single crystal silicon rod, as well as the temperature values ​​at the corresponding measurement points at the measurement times corresponding to each measured resistivity value. The corresponding resistivity compensation value is determined based on a single measured resistivity value and its corresponding temperature value. The resistivity compensation value is then added to the corresponding measured resistivity value to obtain the corresponding resistivity correction value. Based on the resistivity correction value at the head of the current segment of the single crystal silicon rod, the resistivity correction value at the tail, and the expected resistivity, the dopant doping scheme for the silicon melt during the pulling of the second segment of the single crystal silicon rod after the current segment is determined. The dopant doping scheme includes the mass of a first dopant and a second dopant, wherein the volatility of the first dopant is greater than that of the second dopant and the two doping types are the same.

2. The method for controlling the resistivity of single-crystal silicon according to claim 1, characterized in that, The resistivity correction value is determined according to the following method: A table is provided to correspond to the resistivity compensation value with the numerical range of temperature value and resistivity correction value. The table describes the resistivity compensation value corresponding to different temperature values ​​when the resistivity correction value is in different numerical ranges. The values ​​in the table are empirical values. According to the correspondence table, multiple resistivity compensation values ​​corresponding to the temperature value are retrieved. The retrieved resistivity compensation values ​​are added to the measured resistivity value. If the sum is within the resistivity correction value range corresponding to the resistivity compensation value, the sum is determined as the resistivity correction value.

3. The method for controlling the resistivity of single-crystal silicon according to claim 1, characterized in that, Based on the resistivity correction values ​​at the head and tail of the current single-crystal silicon rod and the expected resistivity, determine the dopant application scheme for the silicon melt during the pulling of the second single-crystal silicon rod following the current single-crystal silicon rod, including: If the ratio of the resistivity correction value at the head to the resistivity correction value at the tail of the current monocrystalline silicon rod is greater than a first proportional threshold, the first proportional threshold is greater than 1, and the resistivity at the head of the current monocrystalline silicon rod is greater than the expected resistivity, the following operations are performed: The resistivity correction value of the current segment of the single crystal silicon rod head and the expected resistivity are respectively mapped to carrier concentration. Assuming that the amount of silicon material added to the current segment and the second segment after the current segment are equal, the adjustment amount of the first dopant relative to the current segment is determined according to the difference in carrier concentration between the two segments, so that the expected resistivity of the single crystal silicon rod head during the production of the second segment after the current segment is the target resistivity. The adjustment increment of the first dopant is corrected according to the volatility ratio to determine the amount of the first dopant to be added, wherein the amount of the second dopant to be added is equal to the amount of the second dopant to be added in the current segment. Based on the actual amount of silicon added in the second segment after the current segment and the amount of silicon added in the current segment, the amounts of the first and second dopant are scaled proportionally to obtain the doping scheme for the second segment after the current segment.

4. The method for controlling the resistivity of single-crystal silicon according to claim 1, characterized in that, Based on the resistivity correction values ​​at the head and tail of the current single-crystal silicon rod and the expected resistivity, determine the dopant application scheme for the silicon melt during the pulling of the second single-crystal silicon rod following the current single-crystal silicon rod, including: If the ratio of the resistivity correction value at the head to the resistivity correction value at the tail of the current monocrystalline silicon rod is less than a second proportional threshold, the second proportional threshold is less than 1, and the resistivity at the head of the current monocrystalline silicon rod is less than the expected resistivity, the following operations are performed: The resistivity correction value of the current segment of the single crystal silicon rod head and the expected resistivity are respectively mapped to carrier concentration. Assuming that the amount of silicon material added to the current segment and the second segment after the current segment are equal, the reduction amount of the first dopant relative to the current segment is determined according to the difference in carrier concentration between the two segments, so that the expected resistivity of the single crystal silicon rod head during the production of the second segment after the current segment is the target resistivity. The amount of the first dopant is adjusted according to the volatility ratio to determine the amount of the first dopant to be added, wherein the amount of the second dopant to be added is equal to the amount of the second dopant to be added in the current segment. Based on the actual amount of silicon added in the second segment after the current segment and the amount of silicon added in the current segment, the amounts of the first and second dopant are scaled proportionally to obtain the doping scheme for the second segment after the current segment.

5. The method for controlling the resistivity of single-crystal silicon according to claim 1, characterized in that, Based on the resistivity correction values ​​at the head and tail of the current single-crystal silicon rod and the expected resistivity, determine the dopant application scheme for the silicon melt during the pulling of the second single-crystal silicon rod following the current single-crystal silicon rod, including: If the absolute value of the difference between the ratio of the resistivity correction value at the head of the current segment of the monocrystalline silicon rod to the resistivity correction value at the tail and 1 is less than a third proportional threshold, and the absolute value of the difference between the resistivity correction value at the head of the current segment of the monocrystalline silicon rod and the expected resistivity is greater than a set threshold, the following operations are performed: The resistivity correction value of the current segment of the single crystal silicon rod head and the expected resistivity are respectively mapped to carrier concentration. Assuming that the amount of silicon material added to the current segment and the second segment after the current segment are equal, the increase or decrease of the first dopant and the second dopant relative to the current segment is determined according to the difference in carrier concentration between the two segments during the production of the second segment after the current segment, so that the expected resistivity of the single crystal silicon rod head during the production of the second segment after the current segment is the target resistivity, wherein the mass ratio of the first dopant to the second dopant remains unchanged. Based on the actual amount of silicon added in the second segment after the current segment and the amount of silicon added in the current segment, the amounts of the first and second dopant are scaled proportionally to obtain the doping scheme for the second segment after the current segment.

6. The method for controlling the resistivity of single-crystal silicon according to claim 1, characterized in that, Also includes: If the ratio of the resistivity correction value at the head to the resistivity correction value at the tail of the current segment of the monocrystalline silicon rod is found to fluctuate abnormally, production personnel are prompted to investigate the cause of the fault.

7. A single-crystal silicon resistivity control system, characterized in that, The device includes an electronic device comprising a processor and a memory; the processor and the memory cooperate to enable the electronic device to perform the method as described in any one of claims 1 to 6.

8. The single-crystal silicon resistivity control system according to claim 7, characterized in that, It also includes resistivity measuring instruments and temperature measuring instruments.

9. The single-crystal silicon resistivity control system according to claim 7, characterized in that, The electronic device runs production execution system software, which performs the method as described in any one of claims 1 to 6.

10. A program product, characterized in that, The program product executes the method as described in any one of claims 1 to 6 when it is run.

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