Preparation method and doping process of efficient dopant for monocrystalline silicon

Abstract

The invention belongs to the technical field of doping agent synthesis, and particularly relates to a preparation method and a doping process of an efficient doping agent for monocrystalline silicon, diffusion of the doping agent in the whole preparation process of the monocrystalline silicon is improved by selecting a diffusion accelerant, the surface chemical performance of the doping agent is improved through surface activation treatment, and the doping performance of the doping agent is improved. Meanwhile, anions of the surface active agent can react with oxygen in the monocrystalline silicon to reduce the oxygen content in the monocrystalline silicon, and when the doping agent is prepared, a material which diffuses quickly is selected according to different diffusion speeds of the material, so that holes can be provided for a material which diffuses slowly in time, and the distribution of the doping agent in the monocrystalline silicon is improved; in the doping process, the condition of doping diffusion efficiency is considered, and the distribution of the whole doping agent is more uniform by changing the crystal rotation and crucible rotation rates in the single crystal equipment, so that the electrical properties of the single crystal silicon are ensured.

Description

Technical Field

[0001] The present invention belongs to the technical field of dopant synthesis, and in particular relates to a method for preparing a high-efficiency dopant for single crystal silicon and a doping process thereof. Background Art

[0002] In integrated circuit manufacturing, single-crystal silicon wafers are the basic material; in order to meet the integrated circuit industry's demand for large-size silicon wafers, research on efficient doping technology for large-diameter single-crystal silicon is crucial.

[0003] The preparation of dopants in the existing technology is relatively simple. At the same time, there are some limitations when processing large-diameter single-crystal silicon through the thermal diffusion doping method. The doping concentration of the dopant is uneven. At the same time, the dopant may also aggregate due to the diffusion rate problem, resulting in low doping efficiency.

[0004] Based on the above, it is crucial to study an efficient dopant for single crystal silicon for the preparation of single crystals. Summary of the Invention

[0005] In response to the defects of the prior art, the present invention prepares a high-efficiency dopant for single crystal silicon, which is used for doping single crystal silicon. SiC (silicon carbide) is selected as a diffusion promoter, and its PVP (polyvinyl pyrrolidone) is treated to improve the SiC interface adsorption energy. The silicon carbide is further treated with a surfactant. Since the aluminum ions in the surfactant have a certain positive charge, they can form electrostatic adsorption or chemical bonding with the negative charge centers on the SiC surface. The interaction changes the surface properties of the SiC, forming more active sites on its surface, which is beneficial to the adsorption of the dopant. At the same time, the anions in the surfactant can react with oxygen in the single crystal preparation process to reduce the oxygen content in the single crystal silicon. Further, a composite agent is prepared, and a doping material is selected when preparing the composite agent. Different doping materials are selected according to the diffusion speed. The fast-diffusing material can provide holes for the slow-diffusing material in time, thereby improving the distribution of the dopant in large-diameter single crystal silicon. During the doping process, taking into account the diffusion efficiency of the doping, the crystal rotation and crucible rotation rates in the single crystal equipment are changed to make the overall dopant distribution more uniform, thereby ensuring the electrical properties of the large-diameter single crystal silicon.

[0006] To achieve the above-mentioned object, the technical solution adopted by the present invention is a method for preparing a high-efficiency dopant for single crystal silicon, which comprises the following preparation process:

[0007] Step 1: Weigh 6-9 parts of a diffusion accelerator, add 50 parts of a mixed solvent of ethylene glycol and DMSO (dimethyl sulfoxide), and stir, wherein the ratio of ethylene glycol to DMSO is 70%:30%, to obtain a mixed solution I;

[0008] Step 2: Weigh 0.5-1 part of PVP and add it to the mixed solution I obtained in step 1, ultrasonicate and stir to obtain mixed solution II;

[0009] Step 3: Weigh 3-5 parts of a surfactant and add it to the mixed solution II obtained in step 2, heat and stir, and cool to room temperature to obtain a mixed solution III;

[0010] Step 4: Weigh 2-6 parts of the dopant and add it to the mixed solution III obtained in step 3, stirring, and then slowly add hydrochloric acid solution dropwise thereto, the concentration of the hydrochloric acid solution being 2 mol / L, to obtain a high-efficiency dopant precursor for single crystal silicon;

[0011] Step 5: Dry the high-efficiency dopant precursor for single-crystalline silicon obtained in step 4 under an argon atmosphere with an argon flow rate of 1 L / min, a drying temperature of 400-600°C, and a drying time of 24 hours. Cool to room temperature to obtain a high-efficiency dopant for single-crystalline silicon.

[0012] Furthermore, the diffusion promoter is SiC, the surfactant is a mixture of aluminum chloride and aluminum fluoride, the mass percentage of the aluminum chloride and aluminum fluoride is 45%:55%, and the dopant is either an n-type composite agent or a p-type composite agent.

[0013] Furthermore, the dopant in step 4 is an n-type composite agent, and the preparation method of the n-type composite agent is as follows:

[0014] (i) weighing phosphorus trichloride and arsenic trichloride, pretreating them under an argon atmosphere, and cooling them to room temperature to obtain a phosphorus-arsenic mixture;

[0015] (ii) pre-treating anhydrous toluene by passing argon gas through the mixture, adding the phosphorus-arsenic mixture obtained in step (i) to anhydrous toluene, heating, cooling to room temperature, and washing to obtain an n-type composite agent precursor;

[0016] (iii) drying the n-type composite agent precursor described in step (ii) to obtain an n-type composite agent.

[0017] Furthermore, the dopant in step 4 is a p-type composite agent, and the preparation method of the p-type composite agent is as follows:

[0018] (a) weighing boron powder and aluminum powder, grinding and mixing to obtain a boron-aluminum mixture;

[0019] (b) subjecting the boron-aluminum mixture obtained in step (a) to high-temperature treatment in an argon atmosphere and cooling it to room temperature to obtain a p-type composite agent.

[0020] The present invention also provides a doping process for a high-efficiency dopant for single-crystal silicon, comprising the following process steps:

[0021] Step 1: Set the heater power, argon flow rate, furnace pressure, crystal pulling speed, and ingot size for the single crystal pulling equipment.

[0022] Step 2: Weigh silicon material and high-efficiency dopant, add them into the single crystal equipment, and heat the material;

[0023] Process 3: Adjust the crucible rotation and crystal rotation in the single crystal equipment to the maximum critical value. Before the secondary addition, adjust the crucible rotation and crystal rotation in the single crystal equipment to 1 / 2 of the maximum critical value. After the crucible rotation and crystal rotation are stable, add the secondary silicon material and high-efficiency dopant, and then adjust the crucible rotation and crystal rotation to 3 / 4 of the maximum critical value. Repeat the subsequent addition operation until the silicon material and high-efficiency dopant are completely added, and keep the crucible rotation and crystal rotation in the single crystal equipment at 3 / 4 of the maximum critical value.

[0024] Process 4: After the silicon material is completely melted and there is no shaking on the liquid surface, start seeding, shoulder placement, shoulder rotation, and equal diameter. When the equal diameter reaches the size of the single crystal silicon, adjust the crucible rotation and crystal rotation in the single crystal equipment to 1 / 2 of the maximum critical value. After the equal diameter is completed, the single crystal silicon is taken out.

[0025] The beneficial effects achieved by the present invention are as follows:

[0026] The high-efficiency dopant for single crystal silicon prepared by the present invention uses SiC as a diffusion accelerator, improves SiC interface adsorption energy through PVP treatment, and further treats silicon carbide with a surfactant. Since aluminum ions in the surfactant have a certain positive charge, the aluminum ions can interact with silicon atoms or carbon atoms on the SiC surface to form electrostatic adsorption or chemical bonding at the negative charge centers on the SiC surface. This interaction changes the surface properties of the SiC, forming more active sites on the surface, thereby facilitating the adsorption of the dopant. At the same time, in the process of selecting the dopant, the diffusion speed of the material itself is taken into consideration, and a composite agent is prepared by selecting doping materials with different diffusion rates, thereby providing holes in a timely manner and improving the distribution of the dopant on the single crystal silicon.

[0027] The doping process provided by the present invention takes into account the problem of doping diffusion efficiency caused by large size. By changing the crystal rotation and crucible rotation rates in the single crystal equipment, the overall distribution of dopants is made more uniform, thereby ensuring the electrical properties of large-diameter single crystal silicon. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 This is a diagram of a method for preparing a high-efficiency dopant for single crystal silicon according to an embodiment of the present invention;

[0029] Figure 2 This is a doping process diagram of a high-efficiency dopant for single crystal silicon according to an embodiment of the present invention;

[0030] Figure 3This is a test chart of the oxygen content of single-crystal silicon prepared in an embodiment of the present invention;

[0031] Figure 4 This is a test graph of the life resistance ratio of n-type single crystal silicon prepared in an embodiment of the present invention;

[0032] Figure 5 This is a test graph of the life resistance ratio of the p-type single crystal silicon prepared in an embodiment of the present invention;

[0033] The accompanying drawings are used to provide further understanding of the present invention and constitute a part of the specification. They are used to explain the present invention together with the embodiments of the present invention and do not constitute a limitation of the present invention. DETAILED DESCRIPTION

[0034] The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments; based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0035] Unless otherwise defined, all technical and scientific terms used herein have the same meanings as those familiar to those skilled in the art. Furthermore, any methods and materials similar or equivalent to those described herein can be applied to the present invention. The preferred embodiments and materials described herein are for illustrative purposes only and are not intended to limit the scope of this application.

[0036] The preparation methods in the following examples are described in detail in Figure 1 Unless otherwise specified, all methods are conventional; the dopant in step 4 of Examples 1-3 is an n-type compound, and the dopant in step 4 of Examples 4-6 is a p-type compound; the materials used in the following examples, unless otherwise specified, are all high-purity industrial grade with a purity of 99.99% or above.

[0037] Example 1: A method for preparing a high-efficiency dopant for single-crystalline silicon, comprising the following preparation process:

[0038] Step 1: Weigh 6 mmol of SiC and add 50 ml of a mixed solvent of ethylene glycol and DMSO at a stirring power of 0.8 kW for 30 min, wherein the ratio of ethylene glycol to DMSO is 70%:30% to obtain a mixed solution I;

[0039] Step 2: Weigh 0.5 mmol of PVP-5000 and add it to the mixed solution I obtained in step 1. Ultrasonicate at a power of 50 kHz for 20 minutes and stir at a power of 0.8 kW to obtain a mixed solution II.

[0040] Step 3: Weigh 3 mmol of a mixture of aluminum chloride hexahydrate and anhydrous aluminum fluoride, add it to the mixed solution II obtained in step 2, heat it to 120° C. for 1 hour, and stir it at a power of 0.8 kW, wherein the mass percentage of aluminum chloride hexahydrate and anhydrous aluminum fluoride is 45%:55%, and cool it naturally to room temperature to obtain a mixed solution III;

[0041] Step 4: Weigh 2 mmol of n-type composite agent and add it to the mixed solution III obtained in step 3, stirring at a power of 0.8 kW for 2 hours, and then slowly add 5 ml of hydrochloric acid solution with a concentration of 2 mol / L to obtain a high-efficiency dopant precursor for single crystal silicon;

[0042] Step 5: The high-efficiency dopant precursor for single crystal silicon obtained in step 4 is heated to 400° C. in an argon atmosphere with a flow rate of 1 L / min and dried for 24 hours, and then naturally cooled to room temperature to obtain a high-efficiency dopant for single crystal silicon.

[0043] The preparation method of the n-type composite agent is as follows:

[0044] (i) Weighing 1.2 mmol of phosphorus trichloride and 1 mmol of arsenic trichloride, heating to 105° C. for 30 min under an argon atmosphere at a flow rate of 0.5 L / min, and naturally cooling to room temperature to obtain a phosphorus-arsenic mixture;

[0045] (ii) 30 ml of anhydrous toluene was pre-treated by passing argon gas, and the phosphorus-arsenic mixture obtained in step (i) was added to anhydrous toluene and heated to 220° C. in a reactor for 18 hours. The mixture was naturally cooled to room temperature and washed five times with anhydrous toluene to obtain an n-type composite agent precursor;

[0046] (iii) placing the n-type composite agent precursor described in step (ii) in a vacuum drying oven and drying it at 75° C. for 24 hours to obtain an n-type composite agent.

[0047] This embodiment also provides a doping process for single crystal silicon using a high-efficiency dopant, including the following process steps:

[0048] Process 1: Set the heater power, argon flow rate, furnace pressure, crystal pulling speed, and crystal ingot size in the single crystal equipment;

[0049] Step 2: Weigh silicon material and high-efficiency dopant, add them into the single crystal equipment, and heat the material;

[0050] Process 3: Adjust the crucible rotation and crystal rotation in the single crystal equipment to the maximum critical value. Before the secondary feeding, adjust the crucible rotation and crystal rotation in the single crystal equipment to 1 / 2 of the maximum critical value. After the crucible rotation and crystal rotation are stable, add the secondary silicon material and high-efficiency dopant, and then adjust the crucible rotation and crystal rotation to 3 / 4 of the maximum critical value. The subsequent feeding process is consistent with the secondary feeding process. After the silicon material and high-efficiency dopant are completely added, keep the crucible rotation and crystal rotation in the single crystal equipment at 3 / 4 of the maximum critical value.

[0051] Process 4: After the silicon material is completely melted and there is no shaking on the liquid surface, start seeding, shoulder placement, shoulder rotation, and equal diameter. When the equal diameter reaches the size of the single crystal silicon, adjust the crucible rotation and crystal rotation in the single crystal equipment to 1 / 2 of the maximum critical value. After the equal diameter is completed, the single crystal silicon is taken out.

[0052] Example 2: A method for preparing a high-efficiency dopant for single-crystalline silicon, comprising the following preparation process:

[0053] Step 1: Weigh 7.5 mmol of SiC and add 50 ml of a mixed solvent of ethylene glycol and DMSO at a stirring power of 0.8 kW for 30 min, wherein the ratio of ethylene glycol to DMSO is 70%:30%, to obtain a mixed solution I;

[0054] Step 2: Weigh 0.8 mmol of PVP-5000 and add it to the mixed solution I obtained in step 1. Ultrasonicate at a power of 50 kHz for 20 minutes and stir at a power of 0.8 kW to obtain a mixed solution II.

[0055] Step 3: Weigh 4 mmol of a mixture of aluminum chloride hexahydrate and anhydrous aluminum fluoride, add it to the mixed solution II obtained in step 2, heat it to 120° C. for 1 hour, and stir it at a power of 0.8 kW, wherein the mass percentage of aluminum chloride hexahydrate and anhydrous aluminum fluoride is 45%:55%, and cool it naturally to room temperature to obtain a mixed solution III;

[0056] Step 4: Weigh 4 mmol of n-type composite agent and add it to the mixed solution III obtained in step 3, stirring at a power of 0.8 kW for 2 hours, and then slowly add 5 ml of hydrochloric acid solution with a concentration of 2 mol / L to obtain a high-efficiency dopant precursor for single crystal silicon;

[0057] Step 5: The high-efficiency dopant precursor for single crystal silicon obtained in step 4 is heated to 500° C. in an argon atmosphere with a flow rate of 1 L / min and dried for 24 hours, and then naturally cooled to room temperature to obtain a high-efficiency dopant for single crystal silicon.

[0058] The preparation method of the n-type composite agent and the doping process of a high-efficiency dopant for single crystal silicon in Example 2 are the same as those in Example 1.

[0059] Example 3: A method for preparing a high-efficiency dopant for single-crystalline silicon, comprising the following preparation process:

[0060] Step 1: Weigh 9 mmol of SiC and add 50 ml of a mixed solvent of ethylene glycol and DMSO at a stirring power of 0.8 kW for 30 min, wherein the ratio of ethylene glycol to DMSO is 70%:30% to obtain a mixed solution I;

[0061] Step 2: Weigh 1 mmol of PVP-5000 and add it to the mixed solution I obtained in step 1. Ultrasonicate at a power of 50 kHz for 20 minutes and stir at a power of 0.8 kW to obtain a mixed solution II.

[0062] Step 3: Weigh 5 mmol of a mixture of aluminum chloride hexahydrate and anhydrous aluminum fluoride, add it to the mixed solution II obtained in step 2, heat it to 120° C. for 1 hour, and stir it at a power of 0.8 kW, wherein the mass percentage of aluminum chloride hexahydrate and anhydrous aluminum fluoride is 45%:55%, and cool it naturally to room temperature to obtain a mixed solution III;

[0063] Step 4: Weigh 6 mmol of n-type composite agent and add it to the mixed solution III obtained in step 3, stirring at a power of 0.8 kW for 2 hours, and then slowly add 5 ml of hydrochloric acid solution with a concentration of 2 mol / L to obtain a high-efficiency dopant precursor for single crystal silicon;

[0064] Step 5: The high-efficiency dopant precursor for single crystal silicon obtained in step 4 is heated to 600° C. in an argon atmosphere with a flow rate of 1 L / min and dried for 24 hours, and then naturally cooled to room temperature to obtain a high-efficiency dopant for single crystal silicon.

[0065] The preparation method of the n-type composite agent and the doping process of a high-efficiency dopant for single crystal silicon in Example 3 are the same as those in Example 1.

[0066] Example 4: A method for preparing a high-efficiency dopant for single-crystal silicon, wherein the n-type compound is replaced with a p-type compound, and the rest of the steps are the same as those in Example 1.

[0067] The preparation method of the p-type composite agent is as follows:

[0068] (a) 1 mmol of boron powder and 1.5 mmol of aluminum powder were weighed and ground into a uniform mixture using a ball mill at a speed of 30 r / min to obtain a boron-aluminum mixture;

[0069] (b) The boron-aluminum mixture obtained in step (a) was placed in a graphite crucible, heated to 1200° C. for 6 h in an argon atmosphere with a flow rate of 2 L / min, and the temperature was increased at a rate of 20° C. / min, and naturally cooled to room temperature to obtain a p-type composite agent.

[0070] The doping process of a high-efficiency dopant for single crystal silicon provided in this embodiment is the same as that in embodiment 1.

[0071] Example 5: A method for preparing a high-efficiency dopant for single-crystalline silicon, wherein the n-type compound is replaced with a p-type compound, and the rest of the steps are the same as those in Example 2.

[0072] The preparation method of the p-type composite agent in this embodiment is the same as the preparation method of the p-type composite agent in Example 4;

[0073] The doping process of a high-efficiency dopant for single crystal silicon provided in this embodiment is the same as that in embodiment 1.

[0074] Example 6: A method for preparing a high-efficiency dopant for single-crystalline silicon, wherein the n-type compound is replaced with a p-type compound, and the rest of the steps are the same as those in Example 3.

[0075] The preparation method of the p-type composite agent in this embodiment is the same as the preparation method of the p-type composite agent in Example 4;

[0076] The doping process of a high-efficiency dopant for single crystal silicon provided in this embodiment is the same as that in embodiment 1.

[0077] Comparative Example:

[0078] The difference between Comparative Example 1 and Example 2 is that no n-type compounding agent is added, and the rest of the process is the same as Example 2;

[0079] The difference between Comparative Example 2 and Example 5 is that no p-type compounding agent is added, and the rest is the same as Example 5.

[0080] According to the demand for large diameter single crystal silicon products, the full crucible feeding amount is 1200kg, the large diameter single crystal silicon size is 12 inches, and the single crystal silicon length is 3500mm. In the actual preparation and feeding process, according to Figure 2 Set the relevant parameter requirements to complete the preparation of large-size single crystal silicon.

[0081] Table 1 shows the relevant parameters of the large diameter single crystal silicon preparation process:

[0082]

[0083] Combine Figure 2 As shown in Table 1, a large diameter single crystal silicon of 4100mm was prepared, the first and last 100mm of the crystal rod were removed, and the middle slice was 220mm·220mm·298mm·300μm. The silicon wafer at a length of 1000mm was tested. The test results are as follows Figure 3 、 Figure 4 and Figure 5 As shown, Figure 3The influence of different types of dopants on the oxygen content of the entire single crystal is shown by Figure 3 It can be seen that the oxygen content of the prepared n-type composite is correspondingly lower than that of single atom doping; at the same time, the oxygen content of the prepared p-type composite is correspondingly lower than that of single atom doping, indicating that during the preparation process, the doped anions have a certain effect on the removal of oxygen.

[0084] In order to test the actual doping effect, the lifetime resistance ratio test was performed on 5 points of the prepared silicon wafer. The specific test results are as follows: Figure 4 and Figure 5 As shown, Figure 4 The lifetime resistance ratio test results of the silicon wafer after doping with the n-type composite agent can be seen. For the same n-type composite agent, the numerical deviation in each example is small, indicating that the doping of the n-type composite agent is relatively uniform. For the p-type composite agent, the overall change in the lifetime resistance ratio test of the silicon wafer after doping is small, indicating that the prepared n-type composite agent has good diffusibility.

[0085] Table 2 shows the test results of large-diameter single crystal silicon prepared in comparative example:

[0086] Group A(us / Ω·cm) B(us / Ω·cm) C (us / Ω·cm) D(us / Ω·cm) E(us / Ω·cm) Oxygen content (ppma) Comparative Example 1 2450 2149 1955 3100 1785 11.5 Comparative Example 2 97 152 187 125 130 16.9

[0087] It can be seen from Table 2 above that when the large-diameter single crystal silicon obtained in the comparative example is tested for the lifetime resistance ratio, there are large differences between different points, and the oxygen content is higher than that of the n-type composite agent and the p-type composite agent.

[0088] Obviously, the above comparative examples and embodiments are only a part of the comparative examples and embodiments of the present invention, and they and the comparative examples and embodiments based on such references are all within the scope of protection of this invention.

[0089] While embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions, and variations may be made to these embodiments without departing from the principles and spirit of the invention, and that the scope of the invention is defined by the appended claims and their equivalents.

[0090] The present invention and its embodiments are described above. Such description is not restrictive. The drawings show only one embodiment of the present invention, and actual applications are not limited thereto. In short, if a person skilled in the art is inspired by the above, and does not deviate from the purpose of the present invention, any method and embodiment similar to the technical solution without creative design shall fall within the scope of protection of the present invention.

Claims

1. A method for preparing a high-efficiency dopant for single crystal silicon, characterized in that: The high-efficiency dopant for single crystal silicon comprises the following raw materials in parts by weight: 6-9 parts of a diffusion accelerator, 50 parts of a mixed solvent of ethylene glycol and DMSO, 0.5-1 parts of PVP, 3-5 parts of a surfactant, and 2-6 parts of a dopant; The method for preparing a high-efficiency dopant for single-crystal silicon includes the following preparation process: Step 1: weighing a diffusion accelerator, adding the mixture of ethylene glycol and DMSO into the mixture, and stirring to obtain a mixed solution I; Step 2: PVP is weighed and added to the mixed solution I, and ultrasonicated and stirred to obtain the mixed solution II; Step 3: Weigh the surfactant and add it to the mixed solution II, heat and stir, and cool to obtain the mixed solution III; Step 4: weighing the dopant and adding it to the mixed solution III obtained in step 3 and stirring it, and then adding the acid solution thereto to obtain a high-efficiency dopant precursor for single crystal silicon; Step 5: Dry the single crystal silicon obtained in step 4 with a high-efficiency dopant precursor, cool it, and obtain a high-efficiency dopant for single crystal silicon.

2. The method for preparing a high-efficiency dopant for single crystal silicon according to claim 1, characterized in that: The diffusion promoter in step 1 is SiC, the surfactant in step 3 is a mixture of aluminum chloride and aluminum fluoride, the mass percentage of aluminum chloride and aluminum fluoride is 45%:55%, and the dopant in step 4 is either an n-type composite agent or a p-type composite agent.

3. The method for preparing a high-efficiency dopant for single crystal silicon according to claim 2, characterized in that: The dopant in step 4 is an n-type composite agent, and the preparation method of the n-type composite agent is as follows: (i) pre-treating phosphorus trichloride and arsenic trichloride under an argon atmosphere and cooling to room temperature to obtain a phosphorus-arsenic mixture; (ii) pre-treating anhydrous toluene by passing argon gas, adding the phosphorus-arsenic mixture to anhydrous toluene, heating, cooling to room temperature, and washing to obtain an n-type composite agent precursor; (iii) drying the n-type composite agent precursor to obtain the n-type composite agent.

4. The method for preparing a high-efficiency dopant for single crystal silicon according to claim 2, characterized in that: The dopant in step 4 is a p-type composite agent, and the preparation method of the p-type composite agent is as follows: (a) grinding and mixing boron powder and aluminum powder to obtain a boron-aluminum mixture; (b) The boron-aluminum mixture is subjected to high-temperature treatment in an argon atmosphere and cooled to room temperature to obtain a p-type composite agent.

5. A doping process for a high-efficiency dopant for single crystal silicon, for doping a high-efficiency dopant for single crystal silicon prepared by the method for a high-efficiency dopant for single crystal silicon according to any one of claims 1 to 4, characterized in that: The process includes the following: Process 1: Set the single crystal equipment parameters; Step 2: Weigh silicon material and high-efficiency dopant for single crystal silicon, add them into the single crystal equipment, and heat the material; Process 3: Adjust the crucible rotation and crystal rotation in the single crystal equipment to the maximum critical value. Before the secondary feeding, adjust the crucible rotation and crystal rotation in the single crystal equipment to 1 / 2 of the maximum critical value. After the crucible rotation and crystal rotation are stable, add the secondary silicon material and high-efficiency dopant, and then adjust the crucible rotation and crystal rotation to 3 / 4 of the maximum critical value. The subsequent feeding process is consistent with the secondary feeding process. After the silicon material and high-efficiency dopant are completely added, keep the crucible rotation and crystal rotation in the single crystal equipment at 3 / 4 of the maximum critical value. Process 4: After the silicon material is completely melted and there is no shaking on the liquid surface, start seeding, shoulder placement, shoulder rotation, and equal diameter. When the equal diameter reaches the size of the single crystal silicon, adjust the crucible rotation and crystal rotation in the single crystal equipment to 1 / 2 of the maximum critical value. After the equal diameter is completed, the single crystal silicon is taken out.

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