Method for detecting crystal defects in silicon single crystal substrate

Abstract

To provide a method of visually recognizing and effectively detecting a crystal defect even in a silicon single crystal substrate with low oxygen concentration.SOLUTION: A method of executing a heat treatment to a silicon single crystal substrate and detecting a crystal defect existed in the silicon single crystal substrate, is a detection method of the crystal defect of the silicon single crystal substrate, containing: a step A of measuring an oxygen concentration of the silicon single crystal substrate; a step B of calculating a solid solution critical temperature of oxygen from the oxygen concentration of the measured silicon single crystal substrate; a step C of determining a heat treatment temperature of the heat treatment executed for the silicon single crystal substrate to a range of a temperature that is 800°C or more, and is less than the solid solution critical temperature of oxygen calculated; a step D of executing the heat treatment at the heat treatment temperature determined under an atmosphere containing hydrogen and hydrogen chloride to the silicon single crystal substrate; and a step E of detecting the crystal defect which is visually recognized onto a front surface of the silicon single crystal substrate to which the heat treatment is executed.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a method for detecting crystal defects present in a silicon single crystal substrate with high sensitivity by performing a heat treatment. [Background technology]

[0002] In recent years, with the miniaturization and high integration of semiconductor elements, accurate evaluation of crystal defects existing in semiconductor crystals has become more important. It is widely known that in semiconductor silicon crystals, in regions where vacancy formation is predominant, voids and oxygen precipitates are the main crystal defects, while in regions where interstitial silicon formation is predominant, SFs (Stacking Faults) and dislocation loops are the main crystal defects. These crystal defects are widely known to affect device yields and gettering capabilities, and it is therefore necessary to control the formation of these crystal defects and accurately understand their presence in the manufactured crystals.

[0003] As a method for detecting the above crystal defects with high sensitivity, Patent Document 1 discloses a technique for making crystal defects visible by heat treating a semiconductor single crystal substrate at 800 to 1100° C. in a hydrogen atmosphere. Furthermore, Patent Document 2 discloses a technique in which the surface of a semiconductor substrate is heat-treated at 900-1250°C in a hydrogen atmosphere, and then exposed to a reducing atmosphere containing a gaseous etchant selected from the group consisting of hydrogen chloride, hydrogen bromide, hydrogen iodide, and combinations thereof, to make defects visible at 800-1100°C. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent Publication No. 2011-119528 [Patent Document 2] Patent No. 5998225 Summary of the Invention [Problem to be solved by the invention]

[0005] The technology of the above-mentioned Patent Document 1 is a technology for making crystal defects visible by performing heat treatment in a hydrogen atmosphere, but depending on the level of the substrate, surface defects may disappear and the defects may not be made visible. In addition, the technology of Patent Document 2 is a technology that exposes defects by performing heat treatment in a reducing atmosphere after heat treatment in a hydrogen atmosphere. However, depending on the oxygen concentration of the substrate, the defects may go into solution, and therefore the technology is not applicable to low-oxygen crystals, particularly those with an oxygen concentration of less than 1.2 ppma.

[0006] An object of the present invention is to provide a method for effectively revealing and detecting crystal defects even in a silicon single crystal substrate having a low oxygen concentration. [Means for solving the problem]

[0007] In order to achieve the above object, the present invention provides a method for detecting crystal defects present in a silicon single crystal substrate by subjecting the silicon single crystal substrate to a heat treatment, the method comprising the steps of: A step A of measuring an oxygen concentration of the silicon single crystal substrate; A step B of determining a solid solubility limit temperature of oxygen from the oxygen concentration of the silicon single crystal substrate measured; A step C of determining a heat treatment temperature of the heat treatment to be performed on the silicon single crystal substrate to be in a range of 800° C. or higher and lower than the determined solid solubility limit temperature of oxygen; A step D of subjecting the silicon single crystal substrate to the heat treatment at the determined heat treatment temperature in an atmosphere containing hydrogen and hydrogen chloride; A step E of detecting crystal defects that have become apparent on the surface of the heat-treated silicon single crystal substrate; The present invention provides a method for detecting crystal defects in a silicon single crystal substrate, comprising:

[0008] The detection method of the present invention can effectively reveal crystal defects even in silicon single crystal substrates with a low oxygen concentration (interstitial oxygen concentration), making it possible to detect crystal defects with high sensitivity. By setting the heat treatment temperature at 800°C or higher, it is possible to efficiently expose crystal defects with a short heat treatment time. In addition, by setting the heat treatment temperature below the solubility limit temperature, it is possible to prevent crystal defects from becoming solution-like, particularly in the case of a low oxygen concentration, because the heat treatment temperature is higher than the solubility limit temperature. Therefore, it is possible to reliably expose crystal defects. Furthermore, because the heat treatment is performed in an atmosphere containing hydrogen and hydrogen chloride, a difference occurs in the etching rate between defective and non-defective portions of the silicon single crystal substrate, which can make crystal defects more apparent.

[0009] At this time, the oxygen concentration in the silicon single crystal substrate can be made greater than 0.46 ppma.

[0010] Even in the case of an extremely low oxygen concentration of around 0.46 ppma, the detection method of the present invention can make crystal defects apparent and detect them. The oxygen concentration values ​​in this specification are based on the JEITA standard.

[0011] In addition, when the heat treatment is performed simultaneously on a plurality of the silicon single crystal substrates in the step D, The solubility limit temperature of oxygen determined in the step B can be determined from the lowest oxygen concentration among the plurality of silicon single crystal substrates.

[0012] In this way, crystal defects can be made apparent and detected by simultaneously heat-treating a plurality of silicon single crystal substrates, which is simple and efficient.

[0013] Furthermore, when the heat treatment is performed in the step D, the heat treatment can be performed after the surface of the silicon single crystal substrate is mirror-polished and then cleaned.

[0014] In this way, foreign matter such as metal impurities and particles near the surface of the silicon single crystal substrate can be removed, making it possible to expose only the crystal defects.

[0015] Furthermore, the detection of the crystal defects that have become apparent in the step E can be carried out using at least one of a surface defect detection device and a scanning electron microscope.

[0016] In this way, the density and distribution of crystal defects can be evaluated accurately in a short time by detection with a surface defect inspection device, and the shape, size, composition, crystal defect density, etc. of the crystal defects can be evaluated by detection with a scanning electron microscope. Effect of the Invention

[0017] The method for detecting crystal defects in a silicon single crystal substrate of the present invention makes it possible to reliably make crystal defects apparent and detect them even in the case of a silicon single crystal substrate with an oxygen concentration so low that the defects could not be made apparent by conventional methods. [Brief description of the drawings]

[0018] [Figure 1] FIG. 2 is a flow chart showing an example of the steps of the method for detecting crystal defects in a silicon single crystal according to the present invention. BEST MODE FOR CARRYING OUT THEINVENTION

[0019] Hereinafter, an embodiment of the present invention will be described with reference to the drawings, but the present invention is not limited thereto. As described above, there has been a demand for a method for detecting crystal defects that can reveal and detect defects even in silicon single crystal substrates with low oxygen concentrations where crystal defects cannot be revealed by conventional methods. The inventors have conducted intensive research and found that a method that determines the solubility limit temperature of oxygen from the oxygen concentration measured for a silicon single crystal substrate to be detected for defects, performs a heat treatment (in an atmosphere containing hydrogen and hydrogen chloride) at a heat treatment temperature determined within a temperature range of 800°C or higher and lower than the solubility limit temperature, and detects crystal defects revealed thereby can surely and effectively reveal crystal defects even in silicon single crystal substrates with extremely low oxygen concentrations, and can detect them with high sensitivity, thereby completing the present invention.

[0020] FIG. 1 is a flow chart showing an example of the steps of a method for detecting crystal defects in a silicon single crystal substrate according to the present invention. First, as shown in S1 of FIG. 1, a silicon single crystal substrate (semiconductor silicon substrate) for detecting and evaluating crystal defects is prepared. The silicon single crystal substrate to be evaluated may be one manufactured by the Czochralski method or the floating zone method. The crystal orientation is not particularly limited. The diameter size, resistivity, dopant species, etc. are not particularly limited. In addition, the oxygen concentration is not limited, but can be an extremely low oxygen concentration of more than 0.46 ppma as described later. Even in the case of a substrate with a low oxygen concentration (for example, less than 1.2 ppma) that could not be applied by the conventional method (Patent Document 2, etc.), the present invention can reliably reveal crystal defects.

[0021] Next, as in S2, the oxygen concentration of the silicon single crystal substrate is measured and the temperature of the heat treatment is determined. More specifically, the method includes the following steps AC. The oxygen concentration of the silicon single crystal substrate is measured (Step A). The method for measuring the oxygen concentration of the silicon single crystal substrate is not particularly limited, and the measurement can be performed by, for example, infrared absorption spectroscopy.

[0022] The solubility limit temperature of oxygen is calculated from the oxygen concentration of the silicon single crystal substrate measured in step A (step B). Here, the relationship between the oxygen concentration in a silicon single crystal, in particular the solid solubility (solid solubility limit) [O]s and the solid solubility limit temperature will be described. 3 ) and the solubility limit temperature T(K), various investigations have been conducted. For example, the UCS Semiconductor Fundamental Technology Research Group, Science of Silicon, and Realize Science and Engineering Center Co., Ltd. disclosed the following relationship in 1996: [O]s = 1.91 × 10 22 exp(-1.003 / kT) (where k is 8.62×10 -5 )...(Formula 1) Furthermore, the following relational equation is disclosed by Shimura Fumio in Semiconductor Silicon Crystal Engineering, Maruzen Co., Ltd., 1993: [O]s = 9 × 10 22 exp(-1.52 / kT) (where k is 8.62×10 -5 )...(Formula 2)

[0023] Using the relationship between the oxygen solubility and the solubility limit temperature, such as Equation 1 and Equation 2, the solubility limit temperature at the measured oxygen concentration can be calculated. As mentioned above, the formula for the oxygen solubility disclosed in the reference documents varies. The formula for the oxygen solubility to be used can be determined each time depending on various conditions. Here, we consider the case where the solubility limit temperature is calculated using Equation 1. By the way, the oxygen concentration in formulas 1 and 2 in these documents is based on the old ASTM standard, not the JEITA standard. Therefore, the [O]s (atoms / cm 3 If the value of (A) (old ASTM standard) is A, converting it to (ppma) (JEITA standard) is A / (5×10 16 × 1.6).

[0024] Next, the heat treatment temperature for the heat treatment to be performed on the silicon single crystal substrate in a later step is determined to be in the range of 800° C. or higher and lower than the solubility limit temperature of oxygen determined in step B (step C). In a later process, the silicon single crystal substrate is subjected to a heat treatment to expose the crystal defects. However, if the temperature is below 800°C, etching will not proceed and the crystal defects will not be able to become apparent. Even if they could be made apparent, the etching rate of the substrate will be very slow, requiring an extremely long heat treatment time. Furthermore, if the heat treatment temperature is equal to or higher than the solubility limit temperature, the crystal defects will be converted into solution by the heat treatment, and the crystal defects will not be made visible. Therefore, by setting the heat treatment temperature to a temperature lower than the solubility limit temperature obtained in step B, it is possible to prevent such crystal defects from being converted into solution, and it is possible to reliably make the crystal defects visible. The heat treatment temperature in the heat treatment step can be appropriately determined within such a temperature range. The solubility limit temperature calculated from Equation 1 is a guide for determining the upper limit of the heat treatment temperature, and the heat treatment temperature condition in the actual heat treatment step can more preferably be sufficiently lower than the calculated solubility limit temperature.

[0025] As described above, in order to efficiently expose crystal defects, the heat treatment temperature needs to be 800° C. or higher, and according to formula 1, the oxygen concentration at a solubility limit temperature of 800° C. is 0.46 ppma. Therefore, even in a silicon single crystal substrate having an extremely low oxygen concentration, that is greater than 0.46 ppma but close to 0.46 ppma (in this case, the solubility limit temperature is only slightly higher than 800° C.), by setting the heat treatment temperature to 800° C., which is lower than the solubility limit temperature, it is possible to prevent crystal defects from becoming solidified and expose the crystal defects.

[0026] Steps AC of S2 have been explained, but here we will explain a preferred example in which the detection target for crystal defects is multiple silicon single crystal substrates. In the case where multiple silicon single crystal substrates are simultaneously heat-treated in a later heat treatment step to expose crystal defects, the oxygen concentration is measured for all of the multiple silicon single crystal substrates in step A. Alternatively, if the oxygen concentrations can be considered to be the same, for example, because the portions cut from an ingot are adjacent to each other, one or more substrates may be selected as representatives and only the representative substrates may be measured. In step B, the solubility limit temperature is calculated using Equation 1 from the measured value of the lowest oxygen concentration in the silicon single crystal substrate. Then, in step C, the heat treatment temperature for the subsequent step is determined within the range of 800° C. or higher and lower than the determined solubility limit temperature of oxygen, in the same manner as described above. By using such heat treatment conditions, multiple silicon single crystal substrates can be simultaneously heat-treated under the same heat treatment temperature conditions, which is simple and efficient.

[0027] Next, as in S3, the silicon single crystal substrate is mirror-polished. It is sufficient if the silicon single crystal substrate can be mirror-polished, and this can be done using a double-sided polisher, single-sided polisher, or the like.

[0028] Next, as in S4, the silicon single crystal substrate is cleaned. This cleaning can be performed in two stages, SC-1 cleaning and SC-2 cleaning, or hydrofluoric acid cleaning can be used to remove native oxide films. Furthermore, the two-stage cleaning, SC-1 cleaning and SC-2 cleaning, can be combined with hydrofluoric acid cleaning. If necessary, rinsing with pure water or the like can be performed.

[0029] By carrying out the mirror polishing in S3 and the cleaning in S4, followed by the heat treatment in S5, it is possible to remove foreign matter such as metal impurities and particles near the surface of the silicon single crystal substrate before the heat treatment, which is preferable because it allows only crystal defects to become apparent during the heat treatment.

[0030] Next, as in S5, the silicon single crystal substrate is heat-treated. More specifically, the substrate is heat-treated (step D) in an atmosphere containing hydrogen and hydrogen chloride at the heat treatment temperature determined in step C. The heat treatment device used is not particularly limited, and a conventional resistance heating device or the like can be used. Since the etching rates by hydrogen and hydrogen chloride differ between defect-free and defective areas on the surface of a silicon single crystal substrate, heat treatment in an atmosphere containing hydrogen and hydrogen chloride can form oriented etch pits around the defective areas, making the crystal defects visible. The time for this heat treatment can be determined to be sufficient to make crystal defects visible. For example, it may be 30 seconds or 600 seconds, but considering the throughput, it is preferably within 600 seconds. More preferably, it can be 60 to 180 seconds.

[0031] In addition, in the case of a plurality of silicon single crystal substrates, as described above, the plurality of silicon single crystal substrates are simultaneously heat-treated at a heat treatment temperature determined within a range having an upper limit equal to the solubility limit temperature determined from the lowest oxygen concentration in step C.

[0032] Next, as in S6, crystal defects that have become apparent on the surface of the silicon single crystal substrate that has been heat-treated in S5 (step D) are detected (step E). Also, as in S7, the detected crystal defects are evaluated. The detection means is not particularly limited, and for example, at least one of a surface defect detection device and a scanning electron microscope can be used. By using a surface defect detection device (e.g., MAGICS, SP1, SP2, etc.), defects can be accurately detected in a short time. Furthermore, by detecting using a scanning electron microscope, the type, form, constituent elements, etc. of the crystal defect can be evaluated. Furthermore, both of these may be used, and detection may be performed using a surface defect detection device, and the type, etc. of the crystal defect may be evaluated using a scanning electron microscope based on the detection results.

[0033] The detection method of the present invention as described above can efficiently detect crystal defects in a short time and with high sensitivity, even in the case of a silicon single crystal substrate with an oxygen concentration so low that it is difficult to detect crystal defects using conventional methods, and can reliably detect crystal defects without causing them to become soluble. EXAMPLES

[0034] The present invention will be described in more detail below with reference to examples and comparative examples, but the present invention is not limited to these examples. Example 1 First, as samples to be evaluated, two silicon single crystal substrates with a diameter of 300 mm were prepared, which were manufactured using the Czochralski method under conditions in which void formation was predominant. Next, the oxygen concentration of the silicon single crystal substrate was measured by infrared absorption spectroscopy, and was found to be 12 ppma in both cases. According to the above formula 1, the solid solution limit temperature is about 1260°C, so the heat treatment temperature was determined to be 1000°C. Next, these silicon single crystal substrates were mirror-polished and cleaned (SC-1 cleaning, SC-2 cleaning, and hydrofluoric acid cleaning).

[0035] Then, one of the two pieces was heat-treated at the determined heat treatment temperature in an atmosphere containing hydrogen and hydrogen chloride, where the volume percent concentration of hydrogen chloride was 2%, and the heat treatment time was 60 seconds. The other sheet was not subjected to heat treatment in order to serve as a reference for confirming the effects of the present invention. Thereafter, crystal defects were detected using a surface defect detection device and a scanning electron microscope for the silicon single crystal substrate after the heat treatment (with heat treatment) and a reference silicon single crystal substrate (without heat treatment) that had not been subjected to heat treatment.

[0036] The number of defects detected was compared between those with and without the heat treatment of the present invention, and the effect of making defects more apparent was confirmed. At this time, the defect density without heat treatment was set at 1 for comparison. As a result, the number of defects in the case of "with heat treatment" was 4.1 times that in the case of "without heat treatment," confirming the defect-evident effect of heat treatment in the detection method of the present invention. Table 1 summarizes the various conditions and manifestation effects (defect increase rate) of Example 1, Examples 2 and 3, and Comparative Examples 1 and 2 described below.

[0037] Example 2 First, as samples to be evaluated, two silicon single crystal substrates with a diameter of 300 mm were prepared, which were manufactured using the Czochralski method under conditions in which void formation was predominant. Next, the oxygen concentration of the silicon single crystal substrate was measured by infrared absorption spectroscopy, and was found to be 4.1 ppma in both cases. According to the above formula 1, the solid solution limit temperature is about 1070°C, so the heat treatment temperature was determined to be 1000°C. Next, these silicon single crystal substrates were mirror-polished and cleaned (SC-1 cleaning, SC-2 cleaning, and hydrofluoric acid cleaning).

[0038] Then, one of the two pieces was heat-treated at the determined heat treatment temperature in an atmosphere containing hydrogen and hydrogen chloride, where the volume percent concentration of hydrogen chloride was 2%, and the heat treatment time was 60 seconds. The other sheet was not subjected to heat treatment in order to serve as a reference for confirming the effects of the present invention. Thereafter, crystal defects were detected using a surface defect detection device and a scanning electron microscope for the silicon single crystal substrate after the heat treatment (with heat treatment) and a reference silicon single crystal substrate (without heat treatment) that had not been subjected to heat treatment.

[0039] The number of defects detected was compared between those with and without the heat treatment of the present invention, and the effect of making defects more apparent was confirmed. At this time, the defect density without heat treatment was set at 1 for comparison. As a result, the number of defects in the case of "with heat treatment" was 2.2 times that in the case of "without heat treatment," confirming the defect-evident effect of heat treatment in the detection method of the present invention.

[0040] Example 3 First, as samples to be evaluated, two silicon single crystal substrates with a diameter of 300 mm were prepared, which were manufactured using the Czochralski method under conditions in which void formation was predominant. Next, the oxygen concentration of the silicon single crystal substrate was measured by infrared absorption spectroscopy, and was found to be 2.0 ppma in both cases. Since the solubility limit temperature is about 970°C according to the above formula 1, the heat treatment temperature was determined to be 850°C. Next, these silicon single crystal substrates were mirror-polished and cleaned (SC-1 cleaning, SC-2 cleaning, and hydrofluoric acid cleaning).

[0041] Then, one of the two pieces was heat-treated at the determined heat treatment temperature in an atmosphere containing hydrogen and hydrogen chloride, where the volume percent concentration of hydrogen chloride was 2%, and the heat treatment time was 60 seconds. The other sheet was not subjected to heat treatment in order to serve as a reference for confirming the effects of the present invention. Thereafter, crystal defects were detected using a surface defect detection device and a scanning electron microscope for the silicon single crystal substrate after the heat treatment (with heat treatment) and a reference silicon single crystal substrate (without heat treatment) that had not been subjected to heat treatment.

[0042] The number of defects detected was compared between those with and without the heat treatment of the present invention, and the effect of making defects more apparent was confirmed. At this time, the defect density without heat treatment was set at 1 for comparison. As a result, the number of defects in the case of "with heat treatment" was 5.7 times that in the case of "without heat treatment," confirming the defect-evident effect of heat treatment in the detection method of the present invention.

[0043] Comparative Example 1 First, as samples to be evaluated, two silicon single crystal substrates with a diameter of 300 mm were prepared, which were manufactured using the Czochralski method under conditions in which void formation was predominant. Next, the oxygen concentration of the silicon single crystal substrate was measured by infrared absorption spectroscopy, and was found to be 2.0 ppma in both cases. According to the above formula 1, the solid solution limit temperature is about 970°C, and the heat treatment temperature was determined to be 700°C. Next, the silicon single crystal substrate was mirror-polished and cleaned (SC-1 cleaning, SC-2 cleaning, and hydrofluoric acid cleaning).

[0044] Then, one of the two pieces was heat-treated at the determined heat treatment temperature in an atmosphere containing hydrogen and hydrogen chloride, where the volume percent concentration of hydrogen chloride was 2%, and the heat treatment time was 60 seconds. The other piece was not heat treated in order to serve as a reference for verifying the effect of heat treatment. Thereafter, crystal defects were detected using a surface defect detection device and a scanning electron microscope for the silicon single crystal substrate after the heat treatment (with heat treatment) and a reference silicon single crystal substrate (without heat treatment) that had not been subjected to heat treatment.

[0045] The effect of the heat treatment was confirmed by comparing the number of defects detected with and without the heat treatment. The defect density without heat treatment was set at 1. As a result, the number of defects in the case of "with heat treatment" was 1.4 times that in the case of "without heat treatment," and the effect of the heat treatment on defect manifestation was hardly confirmed. This is thought to be because the etching did not progress because the temperature was less than 800°C, and the crystal defects could not be manifested.

[0046] Comparative Example 2 First, as samples to be evaluated, two silicon single crystal substrates with a diameter of 300 mm were prepared, which were manufactured using the Czochralski method under conditions in which void formation was predominant. Next, the oxygen concentration of the silicon single crystal substrate was measured by infrared absorption spectroscopy, and was found to be 2.0 ppma in both cases. The heat treatment temperature was then determined to be 1000°C. However, the solubility limit temperature calculated from the above formula 1 was approximately 970°C. Next, the silicon single crystal substrate was mirror-polished and cleaned (SC-1 cleaning, SC-2 cleaning, and hydrofluoric acid cleaning).

[0047] Then, one of the two pieces was heat-treated at the determined heat treatment temperature in an atmosphere containing hydrogen and hydrogen chloride, where the volume percent concentration of hydrogen chloride was 2%, and the heat treatment time was 60 seconds. The other piece was not heat treated in order to serve as a reference for verifying the effect of heat treatment. Thereafter, defects were detected using a surface defect detection device and a scanning electron microscope for the silicon single crystal substrate after the heat treatment (with heat treatment) and a reference silicon single crystal substrate (without heat treatment) that had not been subjected to heat treatment.

[0048] The effect of the heat treatment was confirmed by comparing the number of defects detected with and without the heat treatment. The defect density without heat treatment was set at 1. As a result, the number of defects in the case of <with heat treatment> was 1.3 times that of the case of <without heat treatment>, and almost no defect manifestation effect was confirmed. Thus, compared to Example 3, which had the same oxygen concentration, defects could not be fully manifested for detection. Also, although the oxygen concentration was different, the defect manifestation effect (defect increase rate) was smaller than in Examples 1 and 2. This is thought to be due to the fact that the heat treatment temperature (1000°C) was above the solid solution limit temperature (approximately 970°C), causing crystal defects to become liquid.

[0049] [Table 1]

[0050] The present specification includes the following aspects. [1]: A method for detecting crystal defects present in a silicon single crystal substrate by subjecting the silicon single crystal substrate to a heat treatment, comprising the steps of: A step A of measuring an oxygen concentration of the silicon single crystal substrate; A step B of determining a solid solubility limit temperature of oxygen from the oxygen concentration of the silicon single crystal substrate measured; A step C of determining a heat treatment temperature of the heat treatment to be performed on the silicon single crystal substrate to be in a range of 800° C. or higher and lower than the determined solid solubility limit temperature of oxygen; A step D of subjecting the silicon single crystal substrate to the heat treatment at the determined heat treatment temperature in an atmosphere containing hydrogen and hydrogen chloride; A step E of detecting crystal defects that have become apparent on the surface of the heat-treated silicon single crystal substrate; A method for detecting crystal defects in a silicon single crystal substrate, comprising: [2]: The method for detecting crystal defects in a silicon single crystal substrate according to [1] above, wherein the oxygen concentration in the silicon single crystal substrate is greater than 0.46 ppma. [3]: When the heat treatment is performed simultaneously on a plurality of the silicon single crystal substrates in the step D, The method for detecting crystal defects in a silicon single crystal substrate according to the above [1] or [2], wherein the solubility limit temperature of oxygen determined in step B is determined from the lowest oxygen concentration among the plurality of silicon single crystal substrates. [4]: The method for detecting crystal defects in a silicon single crystal substrate according to any one of [1] to [3] above, characterized in that when the heat treatment is performed in step D, the surface of the silicon single crystal substrate is mirror-polished and then cleaned before the heat treatment is performed. [5]: A method for detecting crystal defects in a silicon single crystal substrate according to any one of [1] to [4] above, wherein the detection of the crystal defects that have become apparent in step E is carried out using at least one of a surface defect detection device and a scanning electron microscope.

[0051] The present invention is not limited to the above-described embodiment. The above-described embodiment is merely an example, and anything that has substantially the same configuration as the technical idea described in the claims of the present invention and exhibits similar effects is included in the technical scope of the present invention.

Claims

1. A method for detecting crystal defects present in a silicon single crystal substrate by subjecting the silicon single crystal substrate to a heat treatment, comprising the steps of: A step A of measuring an oxygen concentration of the silicon single crystal substrate; A step B of determining a solid solubility limit temperature of oxygen from the oxygen concentration of the silicon single crystal substrate measured; A step C of determining a heat treatment temperature of the heat treatment to be performed on the silicon single crystal substrate to be in a range of 800° C. or higher and lower than the determined solid solubility limit temperature of oxygen; A step D of subjecting the silicon single crystal substrate to the heat treatment at the determined heat treatment temperature in an atmosphere containing hydrogen and hydrogen chloride; A step E of detecting crystal defects that have become apparent on the surface of the heat-treated silicon single crystal substrate; 1. A method for detecting crystal defects in a silicon single crystal substrate, comprising:

2. 2. The method for detecting crystal defects in a silicon single crystal substrate according to claim 1, wherein the oxygen concentration in the silicon single crystal substrate is set to be greater than 0.46 ppma.

3. When the heat treatment is performed simultaneously on a plurality of the silicon single crystal substrates in the step D, 2. The method for detecting crystal defects in a silicon single crystal substrate according to claim 1, wherein the solubility limit temperature of oxygen determined in step B is determined from the lowest oxygen concentration among the plurality of silicon single crystal substrates.

4. When the heat treatment is performed simultaneously on a plurality of the silicon single crystal substrates in the step D, 3. The method for detecting crystal defects in a silicon single crystal substrate according to claim 2, wherein the solubility limit temperature of oxygen determined in step B is determined from the lowest oxygen concentration among the plurality of silicon single crystal substrates.

5. 5. The method for detecting crystal defects in a silicon single crystal substrate according to claim 1, wherein when the heat treatment is performed in step D, the surface of the silicon single crystal substrate is mirror-polished and then cleaned before the heat treatment.

6. 5. A method for detecting crystal defects in a silicon single crystal substrate as described in any one of claims 1 to 4, characterized in that the detection of the manifested crystal defects in step E is performed using at least one of a surface defect detection device and a scanning electron microscope.

7. 6. The method for detecting crystal defects in a silicon single crystal substrate according to claim 5, wherein the detection of the manifested crystal defects in step E is carried out using at least one of a surface defect detection device and a scanning electron microscope.

Images