Pretreatment method for accurately detecting oxidation induced stacking fault defect of silicon wafer

Abstract

The invention provides a pretreatment method for accurately detecting silicon wafer oxidation induced stacking fault defects, and belongs to the technical field of silicon wafer quality detection.The pretreatment method comprises the steps that S1, a to-be-detected silicon wafer is subjected to preliminary acid pickling polishing so as to remove an oxide layer and a damaged layer on the surface of the to-be-detected silicon wafer; s2, the polished to-be-detected silicon wafer is put into an oxidation annealing furnace to be subjected to oxidation heat treatment, so that the oxidation induced stacking fault defect nucleation growth of the to-be-detected silicon wafer is realized, and the to-be-detected silicon wafer subjected to oxidation heat treatment is subjected to deoxidation by using a hydrofluoric acid solution; s3, carrying out double-sided grinding on the deoxidized silicon wafer to be detected by using a grinding machine so as to further remove a damaged layer; s4, carrying out acid pickling polishing on the ground silicon wafer to be detected again, and removing surface damage caused by grinding; and S5, putting the to-be-detected silicon wafer into the preferential corrosive liquid for corrosion so as to completely expose the oxidation induced stacking fault defect, thereby facilitating detection. Therefore, the oxidation induced stacking fault defect caused in the processing process is completely removed, and the oxidation induced stacking fault defect caused in the crystal pulling process is accurately detected.

Description

Technical Field

[0001] The present invention relates to the technical field of silicon wafer quality inspection, and particularly to a pretreatment method for accurately detecting oxidation-induced stacking fault defects of silicon wafers. Background Art

[0002] Oxidation-induced stacking fault (OISF) defects are important indicators for measuring the quality of silicon wafers. Currently, strict control of OISF is required for silicon materials used in very large scale integrated circuits. The existing pretreatment method for detecting OISF defects is pickling and polishing - oxidation heat treatment - preferential etching. Although this process can detect OISF defects, it cannot ensure whether the OISF is formed by micro-defects during the crystal pulling process or caused by mechanical damage and metal contamination during post-processing. Therefore, there is an urgent need to develop a more accurate method for detecting OISF defects. Summary of the Invention

[0003] In view of this, the present invention provides a pretreatment method for accurately detecting oxidation-induced stacking fault defects of silicon wafers to solve the technical problem of being unable to accurately detect oxidation-induced stacking fault defects caused by the crystal pulling process.

[0004] The technical solution adopted by the present invention to solve its technical problems is as follows: A pretreatment method for accurately detecting oxidation-induced stacking fault defects of silicon wafers, comprising the following steps: S1. Perform preliminary pickling and polishing on the silicon wafer to be tested to remove the oxide layer and damaged layer on the surface of the silicon wafer to be tested; S2. Put the polished silicon wafer to be tested into an oxidation annealing furnace for oxidation heat treatment to cause the oxidation-induced stacking fault defects of the silicon wafer to be tested to nucleate and grow, and use hydrofluoric acid solution to remove the oxidation of the silicon wafer to be tested after oxidation heat treatment; S3. Perform double-sided grinding on the deoxidized silicon wafer to be tested by using a grinding machine to further remove the oxidation-induced stacking fault defects formed by the damage caused during the processing; S4. Perform pickling and polishing on the ground silicon wafer to be tested again to remove the surface damage caused by grinding; S5. Put the silicon wafer to be tested into a preferential etching solution for etching to completely expose the oxidation-induced stacking fault defects for easy detection.

[0005] Preferably, in step S1, the performing preliminary pickling and polishing on the silicon wafer to be tested includes: putting the silicon wafer to be tested into a mixed acid solution and fully reacting for 3 - 5 minutes to remove the surface oxide layer and damaged layer, so as to reduce the interference of oxidation-induced stacking fault defects of the silicon wafer caused by damage.

[0006] Preferably, the composition of the mixed acid solution includes HNO with a mass concentration of 70% 3 、HF with 49% and HAc with 99%, and the volume ratio is HNO3 : HF: HAc: H 2 O = (1 - 2): (3 - 4): (2 - 4): (5 - 6).

[0007] Preferably, in step S2, the polished silicon wafer to be measured is placed in an oxidation annealing furnace for oxidation heat treatment, specifically including: placing the silicon wafer to be measured in an oxidation annealing furnace at 900 - 1100 °C and introducing wet oxygen for 1 - 2 h.

[0008] Preferably, in step S2, the oxidized silicon wafer to be measured after oxidation heat treatment is deoxidized with a hydrofluoric acid solution, specifically including: placing the silicon wafer to be measured in a solution with a volume ratio of HF (49%): H 2 O = 1: 1 - 2 and reacting for 1 - 3 min to remove the oxide film formed on the surface of the silicon wafer to be measured due to oxidation heat treatment.

[0009] Preferably, in step S3, the grinding removal amount is 50 - 100 microns per side.

[0010] Preferably, in step S4, the ground silicon wafer to be measured is pickled and polished again, specifically including the following steps: S41. Place the ground silicon wafer to be measured in a mixed acid solution of nitric acid and hydrofluoric acid and react for 3 - 5 min.

[0011] S42. Take out the silicon wafer and overflow it in pure water to wash away the residual acid solution on the surface.

[0012] Preferably, in step S41, the volume ratio of the mixed acid solution of nitric acid and hydrofluoric acid is HNO 3 (70%): HF (49%) = 1: 1 - 5.

[0013] Preferably, in step S5, the preferential etching solution is Wright solution, which is composed of 49% HF, HAc, CrO 3 , HNO 3 , Cu(NO 3 ) 2 •3H 2 O.

[0014] Preferably, after step S5, the method further includes: placing the etched silicon wafer to be measured in pure water and overflowing it to wash it clean, drying it and then sending it to the detection room to observe the oxidation-induced stacking fault defects of the silicon wafer to be measured.

[0015] Compared with the prior art, the beneficial effects of the present invention are as follows: On the basis of traditional methods, the pretreatment process has been improved. A new step of grinding and pickling and polishing the silicon wafer after heat treatment is added to ensure the complete removal of the oxidation-induced stacking fault defects formed by the damage caused during the processing. Thus, the oxidation-induced stacking fault defects caused during the crystal pulling process can be accurately detected, and the oxidation-induced stacking fault defects can be detected at the front end of crystal pulling, avoiding the additional processing costs caused by flowing to the subsequent processes. At the same time, it can also solve the compensation and disputes regarding the oxidation-induced stacking fault defects between the front and back processes. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a schematic flow chart of the method of the present invention.

[0017] Figure 2 It is a detection result diagram of oxidation-induced stacking fault defects of the embodiment.

[0018] Figure 3 It is a microscope detection result diagram of oxidation-induced stacking fault defects of the embodiment.

[0019] Figure 4 It is a detection result diagram of oxidation-induced stacking fault defects of the comparative example.

[0020] Figure 5 It is a detection result diagram of oxidation-induced stacking fault defects of the comparative example from another angle.

[0021] Figure 6 It is a microscope detection result diagram of oxidation-induced stacking fault defects of the comparative example. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0022] The following further elaborates on the technical solutions and technical effects of the embodiments of the present invention in conjunction with the drawings of the present invention.

[0023] Please refer to Figure 1 , a pretreatment method for accurately detecting oxidation-induced stacking fault defects of a silicon wafer, including the following steps: S1. Perform preliminary pickling and polishing on the silicon wafer to be tested to remove the oxide layer and damaged layer on the surface of the silicon wafer to be tested; S2. Place the polished silicon wafer to be tested in an oxidation annealing furnace for oxidation heat treatment to nucleate and grow the oxidation-induced stacking fault defects of the silicon wafer to be tested, and use a hydrofluoric acid solution to remove the oxidation of the silicon wafer to be tested after oxidation heat treatment; S3. Use a grinding machine to perform double-sided grinding on the deoxidized silicon wafer to be tested to further remove the damaged layer caused during the processing; S4. Perform pickling and polishing on the ground silicon wafer to be tested again to remove the surface damage caused by grinding; S5. Place the silicon wafer to be tested in a preferential etching solution for etching to completely expose the oxidation-induced stacking fault defects for easy detection.

[0024] The present invention first performs preliminary pickling and polishing on the silicon wafer to be tested, removing the oxide layer on the surface of the silicon wafer to be tested and the damage layer formed during the processing, reducing the interference of oxidation-induced stacking fault defects caused by damage; secondly, placing the polished silicon wafer to be tested into an oxidation annealing furnace for oxidation heat treatment, so that the oxidation-induced stacking fault defects of the silicon wafer to be tested nucleate and grow, and using a hydrofluoric acid solution to deoxidize the silicon wafer to be tested after the oxidation heat treatment, facilitating the subsequent observation and detection of oxidation-induced stacking fault defects; then using a grinding machine to perform double-sided grinding on the deoxidized silicon wafer to be tested, further removing the damage layer caused by the processing, thereby completely removing the oxidation-induced stacking fault defects formed by the damage caused by the previous processing, performing pickling and polishing on the ground silicon wafer to be tested again, removing the surface damage caused by grinding, ensuring that the oxidation-induced stacking fault defects caused by the processing are completely removed, and only the oxidation-induced stacking fault defects in the crystal pulling process are retained, so that the oxidation-induced stacking fault defects in the crystal pulling process can be accurately detected.

[0025] Generally, after the crystal bar is formed by crystal pulling, the crystal bar is cut into ingots, and then sample wafers are cut from both ends of the ingot. This sample wafer is used to detect defects, that is, the silicon wafer to be tested mentioned above. The quality of the entire crystal bar is reflected through the defect detection situation, and finally, according to the quality situation of the crystal bar, it is wire-cut into silicon wafers and sent to the subsequent process to be processed into polished wafer products. The silicon wafer will not only form oxidation-induced stacking fault defects during the crystal pulling process, but also mechanical damage and metal contamination during the processing will form oxidation-induced stacking fault defects. For example, during the process of cutting the sample wafer, a damage layer will be formed on the surface of the sample wafer, and the damage layer will form oxidation-induced stacking fault defects. Although theoretically, the oxidation-induced stacking fault defects formed by processing are crescent-shaped, and the oxidation-induced stacking fault defects formed by crystal pulling are dumbbell-shaped, in actual work, the applicant found that it is impossible to distinguish the formation reason of the oxidation-induced stacking fault defects through the morphology. Therefore, the applicant improved the pretreatment process on the basis of the traditional pretreatment method, adding steps of grinding and pickling and polishing the silicon wafer after heat treatment, thereby ensuring that the oxidation-induced stacking fault defects formed by the damage caused by the processing are completely removed, accurately detecting the oxidation-induced stacking fault defects caused by the crystal pulling process, being able to detect the oxidation-induced stacking fault defects at the front end of the crystal pulling, avoiding the additional processing costs caused by flowing to the subsequent process, and at the same time, being able to solve the compensation and disputes regarding the oxidation-induced stacking fault defects between the front and back processes.

[0026] Further, in step S1, performing preliminary pickling and polishing on the silicon wafer to be tested includes: placing the silicon wafer to be tested into a mixed acid solution and fully reacting for 3 - 5 minutes to remove the surface oxide layer and damage layer, so as to reduce the interference of oxidation-induced stacking fault defects of the silicon wafer caused by damage. Specifically, first place the silicon wafer to be tested into a mixed solution of nitric acid, hydrofluoric acid, and acetic acid and react for 3 - 5 minutes to remove the oxide layer and damage layer on the surface of the silicon wafer, making the surface of the silicon wafer achieve the effect of mirror polishing, and reducing the interference of oxidation-induced stacking fault defects caused by damage.

[0027] Further, the composition components of the mixed acid solution include HNO with a mass concentration of 70%, 3 49% HF, and 99% HAc, and the volume ratio is HNO 3 :HF:HAc:H 2 O = (1 - 2):(3 - 4):(2 - 4):(5 - 6).

[0028] Further, in step S2, the polished silicon wafer to be tested is placed in an oxidation annealing furnace for oxidation heat treatment, specifically including: placing the silicon wafer to be tested in an oxidation annealing furnace at 900 - 1100 °C and introducing wet oxygen for 1 - 2 h, so that OISF nucleates and grows under the condition of high-temperature wet oxygen, facilitating subsequent observation and detection. High-temperature oxidation not only helps to reveal OISF defects but also removes some surface impurities, improving the detection effect. As an implementation method, the silicon wafer can be first loaded into the oxidation furnace in a dry oxygen atmosphere at 600 - 900 °C, and heated to 1000 - 1200 °C at a rate of 5 - 20 °C / min in the dry oxygen atmosphere, then kept at a constant temperature for 60 - 120 min in the wet oxygen atmosphere, and then dry oxygen is introduced, and the temperature is decreased to 600 - 900 °C at a rate of 1 - 5 °C / min, and the silicon wafer is taken out of the furnace at 600 - 900 °C.

[0029] Further, in step S2, the oxidized and heat-treated silicon wafer to be tested is deoxidized using a hydrofluoric acid solution, specifically including: placing the silicon wafer to be tested in a solution with a volume ratio of HF (49%):H 2 O = 1:1 - 2 and reacting for 1 - 3 min to remove the oxide film formed on the surface of the silicon wafer to be tested due to oxidation heat treatment. After the silicon wafer to be tested is subjected to oxidation heat treatment, not only will OISF defects nucleate and grow, but also a dense oxide film will be formed on the surface of the silicon wafer. Placing the silicon wafer in a solution with a volume ratio of HF (49%):H2O = 1:1 - 2 and reacting for 1 - 3 min can remove the oxide film on the surface, facilitating subsequent observation and detection.

[0030] Further, in step S3, the grinding removal amount is 50 - 100 microns per side. Among them, the grinding removal amount is designed according to the damage thickness caused by the sample truncation. The silicon wafer to be tested is ground on both sides on a grinding machine to remove 100 - 200 microns, ensuring that the oxidation-induced stacking fault defects formed by the damaged layer of the silicon wafer due to the processing process are completely removed.

[0031] Although the silicon wafers are pickled and polished before oxidation heat treatment to remove the damaged layer caused by the processing, it cannot be completely guaranteed that the damaged layer will be completely removed. After the oxidation heat treatment, the damaged layer on the surface can be completely removed by grinding, and then the oxidation-induced stacking fault defects formed during the processing can be completely removed. Since the oxidation-induced stacking fault defects formed during the crystal pulling process are inside the silicon wafers, and the grinding removes the oxidation-induced stacking fault defects formed by the damaged layer on the surface caused by the processing, the oxidation-induced stacking fault defects formed during the crystal pulling process will not be removed by the grinding operation, thus ensuring that the observed oxidation-induced stacking fault defects must be formed during the crystal pulling process. And only through oxidation heat treatment can the oxidation-induced stacking fault defects nucleate and grow, so the grinding operation will not affect the subsequent observation of the oxidation-induced stacking fault defects.

[0032] Further, in step S4, the ground silicon wafer to be tested is pickled and polished again, which specifically includes the following steps: S41. Put the ground silicon wafer to be tested into a mixed acid solution of nitric acid and hydrofluoric acid and react for 3 - 5 minutes.

[0033] S42. Take out the silicon wafer and overflow it in pure water to wash away the residual acid solution on the surface.

[0034] Since the surface of the ground silicon wafer to be tested will be damaged and oxidation-induced stacking fault defects will be formed, which will interfere with the subsequent observation and detection. Therefore, the ground silicon wafer to be tested is put into a mixed solution of nitric acid and hydrofluoric acid, and polished by the strong reaction of nitric acid and hydrofluoric acid to better remove the damaged layer formed by grinding, ensuring that the observed oxidation-induced stacking fault defects are generated during the crystal pulling process. After polishing, the silicon wafer is overflowed in pure water to wash away the residual acid solution on the surface of the silicon wafer, ensuring the effect of subsequent preferential etching.

[0035] Further, in step S41, the volume ratio of the mixed acid solution of nitric acid and hydrofluoric acid is HNO 3 (70%): HF (49%) = 1:1 - 5.

[0036] Further, in step S5, the preferential etching solution is Wright solution, which consists of hydrofluoric acid (49% by mass concentration), HAc, CrO 3 , HNO 3 , Cu(NO 3 ) 2 •3H 2O. Before use, first prepare chromic acid solution A, which is a mixture of chromium trioxide and water, wherein 30-50g of chromium trioxide is dissolved in every 90ml of water, and then prepare copper nitrate solution B, which is a mixture of copper nitrate trihydrate and water, wherein 5-10g of copper nitrate trihydrate is dissolved in every 180ml of water, and then mix chromic acid solution A, copper acid solution B, nitric acid, acetic acid and hydrofluoric acid in a volume ratio of 1: (1-3): 1: (1-3): (2-4) to obtain a preferential etching solution.

[0037] Furthermore, after step S5, the method further includes: placing the etched silicon wafer to be tested in pure water to overflow and clean it, blowing it dry and sending it to the detection room to observe the oxidation-induced stacking fault defects of the silicon wafer to be tested. During observation, it can be observed under a darkroom spotlight at a changed angle under macroscopic observation. Generally, the OISF-Ring can be clearly observed. It can also be observed under a microscope to see whether there are sporadically distributed oxidation-induced stacking fault defects. The density of the oxidation-induced layer defects can also be directly detected on the surface of the sample. The density can be used to directly determine whether the oxidation-induced stacking fault defects are caused by the crystal pulling process or the processing process. The density here refers to whether the oxidation-induced stacking fault defects on the surface of the sample are sporadically distributed. According to the theory, the crystal pulling process will only cause the oxidation-induced stacking fault defects to form a ring, and will not cause sporadic distribution.

[0038] Select 12 inches lightly doped with boron <100> A crystal ingot with a crystal orientation is cut into two samples at both ends of the crystal ingot, one of which is marked as silicon wafer No. 1 to be tested, and the other is marked as silicon wafer No. 2 to be tested. Silicon wafer No. 1 to be tested is pretreated using the method of the present invention, and silicon wafer No. 2 to be tested is pretreated using a traditional method, and then silicon wafer No. 1 to be tested and silicon wafer No. 2 to be tested are tested respectively. Example

[0039] The first step is to place the No. 1 silicon wafer into a solution containing HNO 3 (70%), HF (49%), HAc (99%), its volume ratio is HNO 3 :HF:HAc:H 2 O=(1-2):(3-4):(2-4):(5-6), fully react in the mixed acid solution for 3-5min to remove the surface oxide layer and damage layer to reduce the OISF defect interference caused by damage. In the second step, the polished No. 1 test silicon wafer is placed in an oxidation annealing furnace at 900-1100℃ and wet oxygen is introduced for 1-2h, so that the oxidation-induced stacking fault defects nucleate and grow under this condition, and an oxide film is formed on the surface of the silicon wafer. The silicon wafer is placed in a volume ratio of HF (49%):H 2React in a solution with a volume ratio of O = 1:1 - 2 for 1 - 3 minutes to remove the oxide film on the surface. In the third step, perform double-sided grinding on the deoxidized silicon wafer No. 1 to be measured on a grinding machine, and the grinding removal amount is 50 - 100 microns for each side. In the fourth step, put the ground silicon wafer No. 1 to be measured into a mixed acid solution with a volume ratio of HNO 3 (70%): HF (49%) = 1:1 - 5 and react for 3 - 5 minutes. Take out the silicon wafer and overflow it in pure water to wash away the residual acid solution on the surface. In the fifth step, put the cleaned silicon wafer No. 1 to be measured into the prepared Wright solution and etch for 5 - 10 minutes. Finally, put the silicon wafer No. 1 to be measured on pure water for overflow cleaning, dry it, and then send it to the detection room for observation. When observing, first observe at different angles under the spotlight in a dark room. As Figure 2 shown, multiple rings of OISF - Ring can be clearly seen. Secondly, place the silicon wafer No. 1 to be measured under a microscope and scan the entire diameter for observation to obtain the detection result as Figure 3 shown.

[0040] Comparative Example In the first step, put the silicon wafer No. 2 to be measured into a mixed acid solution composed of nitric acid (HNO 3 (70%), hydrofluoric acid (HF, 49%), and acetic acid (HAc, 99%). The volume ratio of HNO 3 : HF: HAc: H 2 O = (1 - 2):(3 - 4):(2 - 4):(5 - 6). React fully in the mixed acid solution for 3 - 5 minutes to remove the surface oxide layer and damaged layer to reduce the interference of OISF defects caused by damage. In the second step, put the polished silicon wafer No. 2 to be measured into an oxidation annealing furnace at 900 - 1100 °C and introduce wet oxygen for 1 - 2 hours to nucleate and grow the oxidation-induced stacking fault defects under this condition and form an oxide film on the silicon wafer surface. Put the silicon wafer into a solution with a volume ratio of HF (49%): H 2 O = 1:1 - 2 and react for 1 - 3 minutes to remove the oxide film on the surface. In the third step, put the cleaned silicon wafer No. 2 to be measured into the prepared Wright solution and etch for 5 - 10 minutes. Finally, put the silicon wafer No. 2 to be measured on pure water for overflow cleaning, dry it, and then send it to the detection room for observation. When observing, first observe at different angles under the spotlight in a dark room to obtain the detection diagrams of Figure 4 and Figure 5 . Secondly, place the silicon wafer No. 2 to be measured under a microscope for observation to obtain the detection result as Figure 6 shown.

[0041] As Figure 4 shown, it can be seen that the surface of the silicon wafer No. 2 to be measured is relatively blurred, and no clear multiple rings of OISF - Ring are seen. After changing different angles, as Figure 5As shown, a relatively blurred OISF-Ring can be seen. This is because the oxidation-induced stacking fault defects formed by the damaged layer during the processing are formed on the surface of the silicon wafer to be measured, and the oxidation-induced stacking fault defects formed during the crystal pulling process will present a ring-shaped oxidation-induced stacking fault defect under the spotlight. Therefore, the oxidation-induced stacking fault defects formed during the processing will cover the oxidation-induced stacking fault defects formed during the crystal pulling process, making it impossible to accurately detect the oxidation-induced stacking fault defects formed during the crystal pulling process. By comparing Figure 2 , Figure 4 and Figure 5 , it can be seen that after adding the processes of grinding and polishing after the oxidation heat treatment, the oxidation-induced stacking fault defects formed on the surface of the silicon wafer to be measured during the processing are completely removed, thus clearly presenting the ring-shaped oxidation-induced stacking fault defects formed during the crystal pulling process.

[0042] Furthermore, by comparing Figure 3 and Figure 6 , it can be found that the No. 2 silicon wafer to be measured has sporadic oxidation-induced stacking fault defects under the microscope, while the No. 1 silicon wafer to be measured has no sporadic oxidation-induced stacking fault defects under the microscope, that is, the density of the oxidation-induced stacking fault defects is 0. Combining the observation and detection results under the spotlight, it can not only show that the pretreatment method of the present invention can completely remove the oxidation-induced stacking fault defects formed during the processing, improve the detection accuracy of the oxidation-induced stacking fault defects formed during the crystal pulling process, but also clarify that no sporadic oxidation-induced stacking fault defects are formed during the crystal pulling process.

[0043] Therefore, through the pretreatment method of the present invention, it is possible to ensure the elimination of the interference of the oxidation-induced stacking fault defects caused by the damage during the processing, and truly detect the oxidation-induced stacking fault defects formed during the crystal pulling. The accuracy is relatively high, which can avoid the disputes and compensations caused by the density problem of the oxidation-induced stacking fault defects in the front-end and back-end processes of crystal pulling, and greatly reduce the processing cost loss caused by the interference of the oxidation-induced stacking fault defects formed during the processing.

[0044] The above-disclosed are only the preferred embodiments of the present invention. Of course, the scope of the rights of the present invention cannot be limited by this. Those of ordinary skill in the art can understand all or part of the processes of implementing the above embodiments, and the equivalent changes made according to the claims of the present invention still fall within the scope covered by the present invention.

Claims

1. A pretreatment method for accurately detecting oxidation-induced stacking fault defects in silicon wafers, characterized in that: The following steps are involved: S1. Performing preliminary pickling and polishing on the silicon wafer to be tested to remove the oxide layer and damage layer on the surface of the silicon wafer to be tested; S2, placing the polished silicon wafer to be tested in an oxidation annealing furnace for oxidation heat treatment, so that the oxidation-induced stacking fault defects of the silicon wafer to be tested are nucleated and grown, and deoxidizing the silicon wafer to be tested after the oxidation heat treatment using a hydrofluoric acid solution; S3, using a grinder to perform double-sided grinding on the deoxidized silicon wafer to be tested, so as to further remove the damage layer caused by the processing process; S4, pickling and polishing the ground silicon wafer to be tested again to remove surface damage caused by grinding; S5. Place the silicon wafer to be tested into a selective etching solution for etching to fully expose the oxidation-induced stacking fault defects for easy detection.

2. The pretreatment method for accurately detecting oxidation-induced stacking fault defects in silicon wafers according to claim 1, characterized in that: In step S1, the silicon wafer to be tested is subjected to preliminary pickling and polishing, including: placing the silicon wafer to be tested in a mixed acid solution for sufficient reaction for 3-5 minutes to remove the oxide layer and damage layer on the surface of the silicon wafer to be tested, and reduce the interference of silicon wafer oxidation-induced stacking fault defects caused by damage.

3. The pretreatment method for accurately detecting oxidation-induced stacking fault defects in silicon wafers according to claim 2, characterized in that: The mixed acid solution comprises HNO3 with a mass concentration of 70%, HF with a mass concentration of 49%, and HAc with a volume ratio of HNO3:HF:HAc:H2O=(1-2):(3-4):(2-4):(5-6).

4. The pretreatment method for accurately detecting oxidation-induced stacking fault defects in silicon wafers according to claim 1, characterized in that: In step S2, the polished silicon wafer to be tested is placed in an oxidation annealing furnace for oxidation heat treatment, which specifically includes: placing the silicon wafer to be tested in an oxidation annealing furnace at 900-1100° C. and introducing wet oxygen for 1-2 hours.

5. The pretreatment method for accurately detecting oxidation-induced stacking fault defects in silicon wafers according to claim 4, characterized in that: In step S2, the silicon wafer to be tested after the oxidation heat treatment is deoxidized using a hydrofluoric acid solution, specifically comprising: placing the silicon wafer to be tested in a solution with a volume ratio of HF (49%): H2O = 1: 1-2 for 1-3 minutes to remove the oxide film formed on the surface of the silicon wafer to be tested due to the oxidation heat treatment.

6. The pretreatment method for accurately detecting oxidation-induced stacking fault defects in silicon wafers according to claim 1, characterized in that: In step S3, the grinding removal amount is 50-100 microns per side.

7. The pretreatment method for accurately detecting oxidation-induced stacking fault defects in silicon wafers according to claim 1, characterized in that: In step S4, the ground silicon wafer to be tested is pickled and polished again, which specifically includes the following steps: S41, placing the ground silicon wafer to be tested into a mixed acid solution of nitric acid and hydrofluoric acid to react for 3-5 minutes; S42. Take out the silicon wafer and overflow it in pure water to clean the acid remaining on the surface.

8. The pretreatment method for accurately detecting oxidation-induced stacking fault defects in silicon wafers according to claim 7, characterized in that: In step S41, the volume ratio of the mixed acid solution of nitric acid and hydrofluoric acid is HNO3 (70%): HF (49%) = 1: 1-5.

9. The pretreatment method for accurately detecting oxidation-induced stacking fault defects in silicon wafers according to claim 1, characterized in that: In step S5, the preferential etching solution is Wright solution, which is composed of HF, HAc, CrO3, HNO3, and Cu(NO3)2•3H2O with a mass concentration of 49%.

10. The pretreatment method for accurately detecting oxidation-induced stacking fault defects in silicon wafers according to any one of claims 1 to 9, characterized in that: After step S5, the method further comprises: placing the corroded silicon wafer to be tested in pure water for overflow cleaning, blowing it dry and sending it into a testing room to observe oxidation-induced stacking fault defects of the silicon wafer to be tested.

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