Silicon wafer and detection method thereof

Abstract

The disclosed embodiment discloses a silicon wafer and a detection method thereof, and relates to the field of semiconductor manufacturing technology. The detection method comprises: forming a thin film layer by depositing on the surface of the silicon wafer to be tested through a deposition process; obtaining mechanical parameters of the silicon wafer to be tested based on the thickness and a first curvature radius of the silicon wafer to be tested before the deposition process is performed, the second curvature radius of the silicon wafer to be tested after the deposition process is performed, and the stress coefficient corresponding to the deposition process; and performing a level determination on the silicon wafer to be tested based on the mechanical parameters of the silicon wafer to be tested.

Description

Technical Field

[0001] The embodiments of the present disclosure relate to the field of semiconductor manufacturing technology, and more particularly to a silicon wafer and a detection method thereof. Background Art

[0002] With the rapid development of the semiconductor industry, higher standards are currently being put forward for the mechanical strength of silicon wafers. On the one hand, silicon wafers with high mechanical strength can withstand higher mechanical processing such as grinding or polishing, thereby reducing the breakage and damage of silicon wafers; on the other hand, silicon wafers with high mechanical strength can better resist thermal stress and reduce deformation and cracking during heat treatment; in addition, silicon wafers with high mechanical strength can improve the reliability of corresponding semiconductor devices, thereby reducing the failure of semiconductor devices caused by substandard mechanical strength of semiconductor devices during the use of semiconductor devices.

[0003] However, according to some relevant mechanical property testing methods, the silicon wafer is cut into multiple small samples for testing, resulting in the test results being unable to accurately characterize the overall mechanical properties of the silicon wafer. In addition, when the silicon wafer is in a composite process environment of high temperature and force load, a single mechanical property index often cannot accurately reflect the deformation of the silicon wafer in this composite process environment. Therefore, there is currently no effective testing method in the prior art to evaluate the mechanical strength of silicon wafers, and it is difficult to predict the performance of silicon wafers in the above-mentioned composite process environment, and it is even more difficult to select silicon wafers that can work stably in a composite process environment of high temperature and force load. Summary of the invention

[0004] In view of this, the embodiments of the present disclosure hope to provide a silicon wafer and a detection method thereof; the silicon wafer can work stably in a composite process environment of high temperature and force load; in addition, the detection method can accurately detect the mechanical strength of the silicon wafer and obtain the deformation of the silicon wafer in the composite process environment of high temperature and force load, and through the detection method, the level of the silicon wafer can be determined based on the mechanical strength of the silicon wafer, thereby obtaining a silicon wafer that can work stably in a composite process environment of high temperature and force load.

[0005] The technical solution of the embodiment of the present disclosure is implemented as follows:

[0006] In a first aspect, an embodiment of the present disclosure provides a silicon wafer having a mechanical parameter greater than 180 GPa; wherein the mechanical parameter is obtained based on the thickness and a first curvature radius of the silicon wafer before a deposition process is performed, the second curvature radius of the silicon wafer after the deposition process is performed, and a stress coefficient corresponding to the deposition process; the mechanical parameter is used to characterize the mechanical strength of the silicon wafer.

[0007] In some examples, the mechanical parameters of the silicon wafer are greater than 230 GPa.

[0008] In a second aspect, an embodiment of the present disclosure provides a method for detecting a silicon wafer, the method comprising:

[0009] A thin film layer is deposited on the surface of the silicon wafer to be tested through a deposition process;

[0010] Based on the thickness and the first curvature radius of the silicon wafer to be tested before the deposition process is performed, the second curvature radius of the silicon wafer to be tested after the deposition process is performed, and the stress coefficient corresponding to the deposition process, the mechanical parameters of the silicon wafer to be tested are obtained; wherein the mechanical parameters are used to characterize the mechanical strength of the silicon wafer to be tested;

[0011] Based on the mechanical parameters of the silicon wafer to be tested, the level of the silicon wafer to be tested is determined.

[0012] In some examples, the deposition process includes a deposition temperature of 450°C to 1000°C.

[0013] In some examples, the thickness of the thin film layer is comprised between 150 nm and 6000 nm.

[0014] In some examples, the material of the thin film layer includes silicon or a silicon-containing compound.

[0015] In some examples, obtaining the mechanical parameters of the silicon wafer to be tested based on the thickness and the first curvature radius of the silicon wafer to be tested before the deposition process is performed, the second curvature radius of the silicon wafer to be tested after the deposition process is performed, and the stress coefficient corresponding to the deposition process includes:

[0016] Based on the first radius of curvature and the second radius of curvature, obtaining a curvature change of the silicon wafer to be tested after performing the deposition process;

[0017] Based on the thickness, the curvature variation and the stress coefficient, the mechanical parameters of the silicon wafer to be tested are obtained.

[0018] In some examples, the step of determining the level of the silicon wafer to be tested based on the mechanical parameters of the silicon wafer to be tested includes:

[0019] When the mechanical parameter of the silicon wafer to be tested is greater than a preset first target parameter, determining that the silicon wafer to be tested is a first-level silicon wafer;

[0020] When the mechanical parameter of the silicon wafer to be tested is greater than a preset second target parameter and less than a preset first target parameter, the silicon wafer to be tested is determined to be a secondary silicon wafer; wherein the second target parameter is less than the first target parameter;

[0021] When the mechanical parameter of the silicon wafer to be tested is less than a preset second target parameter, it is determined that the silicon wafer to be tested is a third-level silicon wafer.

[0022] In some examples, before performing the deposition process, the detection method further includes:

[0023] The crystal rod segment cut from the crystal rod to be tested is used as the crystal rod segment to be tested;

[0024] At least one silicon wafer among the multiple silicon wafers cut from the crystal rod segment to be tested is used as the silicon wafer to be tested.

[0025] In some examples, after the level of the silicon wafer to be tested is determined, the detection method further includes:

[0026] The level of the silicon wafer to be tested is determined based on the level of the silicon wafer to be tested.

[0027] The embodiment of the present disclosure provides a silicon wafer and a detection method thereof; the silicon wafer can work stably in a composite environment of high temperature and force load. The detection method provides a high-temperature environment to the silicon wafer to be tested through a deposition process, and deposits a thin film layer on the surface of the silicon wafer to be tested to provide a force load to the silicon wafer to be tested, thereby calculating the mechanical parameters used to characterize the mechanical strength of the silicon wafer to be tested according to the thickness of the silicon wafer to be tested, and the first radius of curvature and the second radius of curvature of the silicon wafer to be tested before and after the deposition of the thin film layer. Thereafter, the level of the silicon wafer to be tested is determined according to the mechanical parameters of the silicon wafer to be tested, so as to select a silicon wafer that can work stably in a composite environment of high temperature and force load. In the present disclosure, there is no need to prepare small samples of the silicon wafer to be tested, and the detection results are accurate and will not cause waste to the product. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 A schematic diagram of a silicon wafer detection method provided in an embodiment of the present disclosure;

[0029] Figure 2 A schematic diagram of a silicon wafer to be tested with a thin film layer formed by surface deposition provided by an embodiment of the present disclosure;

[0030] Figure 3 A schematic diagram of the relationship between the mechanical parameters and the curvature variation provided in the embodiment of the present disclosure;

[0031] Figure 4 A schematic flow chart of a method for detecting a crystal rod provided in Example 1 of the present disclosure;

[0032] Figure 5 A schematic diagram of a process flow of a silicon wafer detection method provided in Embodiment 2 of the present disclosure;

[0033] Figure 6 A schematic flow chart of the method for detecting silicon wafers provided in Example 3 of the present disclosure. DETAILED DESCRIPTION

[0034] The technical solutions in the embodiments of the present disclosure will be clearly and completely described below in conjunction with the drawings in the embodiments of the present disclosure.

[0035] See also Figure 1 , which shows a silicon wafer detection method provided by an embodiment of the present disclosure, and the detection method specifically includes the following steps.

[0036] In step S101 , a thin film layer is deposited on the surface of the silicon wafer to be tested through a deposition process.

[0037] In the present disclosure, in order to accurately detect the mechanical strength of the silicon wafer to be tested under the combined environment of high temperature and force load, such as Figure 2 As shown, the inventors envision that a thin film layer 20 is formed by deposition on the surface of the silicon wafer 10 to be tested so that the silicon wafer to be tested is subjected to high temperature and force load at the same time. Specifically: the process of depositing a thin film layer 20 on the surface of the silicon wafer 10 to be tested involves a high temperature environment, so this deposition process can be used to characterize the high temperature environment in which the silicon wafer to be tested is located. During the deposition process, the thin film layer will produce mechanical stress, and the mechanical stress can be used to characterize the force load borne by the silicon wafer to be tested. Therefore, the method of depositing a thin film layer on the surface of the silicon wafer to be tested can be used to obtain the mechanical strength of the silicon wafer to be tested in a composite environment of high temperature and force load.

[0038] In the present disclosure, the mechanical strength mentioned above refers to the ability of the silicon wafer to resist deformation. In the semiconductor manufacturing process, mechanical strength is a key indicator for evaluating the silicon wafer to be tested, because it is directly related to the reliability and durability of the semiconductor device corresponding to the silicon wafer to be tested.

[0039] In some examples, the method corresponding to the deposition process is not specifically limited in the present disclosure. For example, chemical vapor deposition (CVD) and physical vapor deposition (PVD) can be used to deposit a thin film layer on the surface of the silicon wafer to be tested.

[0040] It is understandable that after the deposition process, the silicon wafer to be tested needs to be cleaned after the deposition process, for example, it can be cleaned using a HF+SC1+SC2 combination solution.

[0041] In step S102, based on the thickness and the first curvature radius of the silicon wafer to be tested before the deposition process is performed, the second curvature radius of the silicon wafer to be tested after the deposition process is performed, and the stress coefficient corresponding to the deposition process, the mechanical parameters of the silicon wafer to be tested are obtained; wherein the mechanical parameters are used to characterize the mechanical strength of the silicon wafer to be tested.

[0042] After a thin film layer is deposited on the surface of the silicon wafer to be tested, for the thin film layer of isotropic material, the mechanical stress generated by the thin film layer is expressed as follows:

[0043] (1)

[0044] in, E s Represents the Young's modulus of the silicon wafer to be tested; υ s It represents the Poisson's ratio of the silicon wafer to be tested; t s Indicates the thickness of the silicon wafer to be tested; t f Indicates the thickness of the film layer; R i represents a first curvature radius of the silicon wafer to be tested before performing a deposition process; R f It represents the second curvature radius of the silicon wafer to be tested after the deposition process is performed.

[0045] Simplifying formula (1) yields:

[0046] (2)

[0047] in, .

[0048] Then according to formula (2), we can obtain:

[0049] (3)

[0050] For the silicon wafer to be tested, is a quantity related to the parameter indicating the mechanical strength of the silicon wafer to be tested, so the inventors divide the part related to the mechanical strength of the silicon wafer to be tested into The mechanical parameters are limited to the above However, considering that the silicon wafer to be tested needs to withstand high temperature and force load at the same time, this method is not used in this disclosure. Instead of calculating the mechanical parameters, the thin film deposition method is used to simulate the process environment of high temperature and force load, so as to calculate the mechanical parameters using formula (3).

[0051] The above stress coefficient It can be expressed as: .

[0052] Based on the above formula (3), when the film stress is known , the thickness of the silicon wafer to be measured t s , the thickness of the film layer t f , the first curvature radius of the silicon wafer to be tested before the deposition process is performed R i and a second curvature radius of the silicon wafer to be tested after the deposition process is performed R f Under this condition, the mechanical parameters of the silicon wafer to be tested can be obtained. The inventors imagine that, when the same deposition process is used, the above mechanical parameters are used It is possible to characterize the mechanical strength of the silicon wafer under test. This is mainly due to the known film stress , the thickness of the silicon wafer to be measured t s , the thickness of the film layer t f In the case of , the mechanical parameters are related to the radius of curvature of the silicon wafer to be tested before and after the thin film layer is deposited. It can be understood that the radius of curvature of the silicon wafer to be tested before and after the thin film layer is deposited can be used to evaluate the degree of bending of the silicon wafer to be tested due to the film stress. A larger curvature change indicates that the mechanical strength of the silicon wafer to be tested is lower. Therefore, the mechanical strength of the silicon wafer to be tested can be evaluated using the above mechanical parameters.

[0053] In step S103 , the level of the silicon wafer to be tested is determined based on the mechanical parameters of the silicon wafer to be tested.

[0054] It can be understood that when the mechanical parameters of the silicon wafer to be tested are known, the mechanical strength of the mechanical parameters to be tested can be obtained, so as to make a level judgment on the silicon wafer to be tested, so as to select products that can be suitable for the composite process environment of high temperature and force load according to process requirements.

[0055] In the present disclosure, the product level can be divided into three levels in the above-mentioned level determination, namely: first-level silicon wafer, second-level silicon wafer and third-level silicon wafer. Specifically, when the mechanical parameter of the silicon wafer to be tested is greater than the preset first target parameter, the silicon wafer to be tested is determined to be a first-level silicon wafer. At this time, the mechanical strength of the silicon wafer to be tested is excellent, indicating that the silicon wafer to be tested can be fully applicable to the composite process environment of high temperature and force load. Alternatively, when the mechanical parameter of the silicon wafer to be tested is greater than the preset second target parameter and less than the preset first target parameter, the silicon wafer to be tested is determined to be a second-level silicon wafer. At this time, the mechanical strength of the silicon wafer to be tested is slightly less than that of the first-level silicon wafer, but the silicon wafer to be tested can also be applicable to the composite process environment of high temperature and force load. Alternatively, when the mechanical parameter of the silicon wafer to be tested is less than a preset second target parameter, the silicon wafer to be tested is determined to be a third-level silicon wafer. At this time, the mechanical strength of the silicon wafer to be tested is poor, indicating that the silicon wafer to be tested cannot be suitable for the composite process environment of high temperature and force load. Therefore, the silicon wafer to be tested can be downgraded for use as a test silicon wafer.

[0056] for Figure 1 The technical solution shown provides a high-temperature environment to the silicon wafer to be tested through a deposition process, and deposits a thin film layer on the surface of the silicon wafer to be tested to provide a force load to the silicon wafer to be tested, thereby calculating the mechanical parameters used to characterize the mechanical strength of the silicon wafer to be tested according to the thickness of the silicon wafer to be tested, and the first radius of curvature and the second radius of curvature of the silicon wafer to be tested before and after the deposition of the thin film layer. Thereafter, the level of the silicon wafer to be tested is determined according to the mechanical parameters of the silicon wafer to be tested, so as to select a product silicon wafer that can work stably in a composite environment of high temperature and force load. In the present disclosure, there is no need to prepare small samples of the silicon wafer to be tested, and the test results are accurate and will not cause waste to the product.

[0057] for Figure 1 In the technical solution shown, in some possible implementations, the deposition process includes a deposition temperature of 450°C to 1000°C.

[0058] It can be understood that the deposition temperature in the deposition process defined in the present disclosure is used to characterize the high temperature environment to which the silicon wafer to be tested is subjected, so as to accurately evaluate the mechanical strength of the silicon wafer to be tested in the high temperature environment.

[0059] for Figure 1 In the technical solution shown, in some possible implementations, the thickness of the thin film layer ranges from 150 nm to 6000 nm.

[0060] It can be understood that the thickness of the thin film layer defined in the present disclosure is used to characterize the force load borne by the silicon wafer to be tested. When thin film layers of different thicknesses are deposited on the surface of the silicon wafer to be tested, the mechanical stress generated by the thin film layer is different, so the force load borne by the silicon wafer to be tested is different, and the mechanical strength of the silicon wafer to be tested under different force loads can be accurately evaluated.

[0061] For the above-mentioned embodiments, in some examples, the material of the thin film layer includes silicon or a silicon-containing compound.

[0062] In some examples, the silicon-containing compound is silicon dioxide, silicon carbide, silicon nitride, etc., but is not limited to silicon dioxide, silicon carbide, or silicon nitride.

[0063] It can be understood that thin film layers made of different materials produce different thin film stresses during the deposition process, and thus the force loads borne by the silicon wafer to be tested are different. Therefore, in the present disclosure, the material of the thin film layer is limited to accurately evaluate the mechanical strength of the silicon wafer to be tested under different force loads.

[0064] for Figure 1 In some possible implementations of the technical solution shown, based on the thickness and the first curvature radius of the silicon wafer to be tested before the deposition process is performed, the second curvature radius of the silicon wafer to be tested after the deposition process is performed, and the stress coefficient corresponding to the deposition process, the mechanical parameters of the silicon wafer to be tested are obtained, including:

[0065] Based on the first radius of curvature and the second radius of curvature, obtaining a curvature change of the silicon wafer to be tested after performing a deposition process;

[0066] Based on the thickness, curvature change and stress coefficient, the mechanical parameters of the silicon wafer to be tested are obtained.

[0067] According to formula (3) and stress coefficient k It can be seen that the mechanical parameters Therefore, in the specific implementation process, we first need to calculate the curvature radius according to the first R i With the second radius of curvature R f Obtain the curvature change Δ of the silicon wafer to be tested after the deposition process is performed B ,in .

[0068] In addition, in the present disclosure, it is necessary to know the stress coefficient in advance. k For the stress coefficients in different deposition processes k, a set deposition method is used to deposit a thin film layer on the surface of a standard silicon wafer, and then the mechanical stress generated by the thin film layer is obtained by using X-ray diffraction method or optical stress measurement method, thereby obtaining the corresponding stress coefficient according to the mechanical stress generated by the thin film layer and the thickness of the thin film layer k . Specifically, the X-ray diffraction method uses X-ray diffraction technology to measure the change in lattice parameters of the silicon wafer to be tested after the deposition process is performed, and the mechanical stress generated by the thin film layer is obtained through the change in lattice parameters. The optical stress measurement method uses an optical microscope or interferometer to measure the degree of bending of the silicon wafer to be tested caused by the thin film layer, thereby inferring the mechanical stress generated by the thin film layer. In addition, after knowing the Young's modulus and Poisson's ratio of the standard silicon wafer, a thin film layer can be deposited on the surface of the standard silicon wafer to obtain the radius of curvature of the standard silicon wafer before and after the deposition process, and finally the stress coefficient corresponding to the standard silicon wafer can be inferred according to formula (1). k .

[0069] It should be noted that the above-mentioned standard silicon wafer refers to a silicon wafer obtained using the same production parameters as the selected silicon wafer sample when the silicon wafer sample meets the use requirements after testing. In the specific implementation process, the standard silicon wafer and the silicon wafer sample can be cut from the same crystal rod and located at adjacent positions on the crystal rod, and the product performance is the same.

[0070] Understandably, when the stress coefficient is known k , the curvature change Δ B After the thickness of the silicon wafer to be tested before the deposition process is performed, the mechanical parameters of the silicon wafer to be tested can be obtained, thereby evaluating the mechanical strength of the silicon wafer to be tested.

[0071] In addition, the inventors fitted the obtained mechanical parameter data of the silicon wafer to be tested with the bending data of the silicon wafer to be tested under the composite process environment of high temperature and force load, as shown in the following figure: Figure 3 As shown. Figure 3 It can be seen that the mechanical parameters of the silicon wafer to be tested are linearly related to its bending in a composite process environment of high temperature and force load. Therefore, the mechanical parameters provided by the embodiment of the present disclosure can be used to monitor the deformation of the silicon wafer to be tested in a composite process environment of high temperature and force load.

[0072] for Figure 1 In some possible implementations of the technical solution shown, the level of the silicon wafer to be tested is determined based on the mechanical parameters of the silicon wafer to be tested, including:

[0073] When the mechanical parameter of the silicon wafer to be tested is greater than a preset first target parameter, the silicon wafer to be tested is determined to be a first-level silicon wafer;

[0074] When the mechanical parameter of the silicon wafer to be tested is greater than the preset second target parameter and less than the first target parameter, the silicon wafer to be tested is determined to be a second-level silicon wafer; wherein the second target parameter is less than the first target parameter;

[0075] When the mechanical parameter of the silicon wafer to be tested is less than the second target parameter, it is determined that the silicon wafer to be tested is a third-level silicon wafer.

[0076] It should be noted that the first target parameter and the second target parameter are determined according to the mechanical strength required in the composite process environment of high temperature and force load. For example, when the first target parameter corresponding to the mechanical strength required in the composite process environment of high temperature and force load is set to 230GPa, and the second target parameter is 180GPa, when the mechanical parameters of the silicon wafer to be tested are greater than 230GPa, it is characterized that the silicon wafer to be tested is a first-level silicon wafer, and its mechanical strength meets the composite process environment of high temperature and force load. When the mechanical parameters of the silicon wafer to be tested are greater than 180GPa, but less than 230GPa, it is characterized that the silicon wafer to be tested is a second-level silicon wafer, and its mechanical strength is less than the mechanical strength of the first-level silicon wafer, which can also meet the composite process environment of high temperature and force load. When the mechanical parameters of the silicon wafer to be tested are less than 180GPa, it is characterized that the silicon wafer to be tested is a third-level silicon wafer, and its mechanical strength does not meet the composite process environment of high temperature and force load, and can be downgraded for use as a test piece.

[0077] It should be noted that when the product is an epitaxial silicon wafer, the detection method provided by the present disclosure can also be applied to the detection of the mechanical strength of the epitaxial silicon wafer. Specifically, when the mechanical strength of the silicon wafer to be tested can meet the composite process environment of high temperature and force load, it is characterized that the mechanical strength of the epitaxial silicon wafer with a thin film layer deposited on the surface of the silicon wafer to be tested can also meet the composite process environment of high temperature and force load.

[0078] for Figure 1 In some possible implementations of the technical solution shown, before performing the deposition process, the detection method further includes:

[0079] The crystal rod segment cut from the crystal rod to be tested is used as the crystal rod segment to be tested;

[0080] At least one silicon wafer among the multiple silicon wafers cut from the crystal rod segment to be tested is used as the silicon wafer to be tested.

[0081] In the present disclosure, the level of the crystal rod segment where the silicon wafer to be tested is located can also be determined using the test result of the silicon wafer to be tested. Specifically, the crystal rod segment cut from the crystal rod to be tested is used as the crystal rod segment to be tested; at least one silicon wafer among the multiple silicon wafers cut from the crystal rod segment to be tested is used as the silicon wafer to be tested. Afterwards, after the level of the silicon wafer to be tested is determined, the detection method further includes:

[0082] The level of the silicon wafer to be tested is determined based on the level of the silicon wafer to be tested.

[0083] In the specific implementation process, when the silicon wafer to be tested is determined to be a first-level silicon wafer, the crystal rod to be tested corresponding to the silicon wafer to be tested is determined to be a first-level crystal rod, that is, the multiple silicon wafers cut from the first-level crystal rod are all first-level silicon wafers. Alternatively, when the silicon wafer to be tested is determined to be a second-level silicon wafer, the crystal rod to be tested corresponding to the silicon wafer to be tested is determined to be a second-level crystal rod, that is, the multiple silicon wafers cut from the second-level crystal rod are all second-level silicon wafers. Alternatively, when the silicon wafer to be tested is determined to be a third-level silicon wafer, the crystal rod to be tested corresponding to the silicon wafer to be tested is determined to be a third-level crystal rod, that is, the multiple silicon wafers cut from the third-level crystal rod are all third-level silicon wafers.

[0084] In addition, an embodiment of the present disclosure also provides a silicon wafer, which is determined to be a first-level silicon wafer, a second-level silicon wafer, or a third-level silicon wafer according to the detection method described in the aforementioned technical solution.

[0085] Finally, an embodiment of the present disclosure also provides a silicon wafer having a mechanical parameter greater than 180 GPa; wherein the mechanical parameter is obtained based on the thickness and the first curvature radius of the silicon wafer before performing the deposition process, the second curvature radius of the silicon wafer after performing the deposition process, and the stress coefficient corresponding to the deposition process; the mechanical parameter is used to characterize the mechanical strength of the silicon wafer.

[0086] In some examples, the mechanical parameters of the silicon wafer are greater than 230 GPa.

[0087] The technical solution of the present disclosure is described in more detail below using specific embodiments.

[0088] Example 1

[0089] like Figure 4 As shown, a method for detecting a crystal rod is shown, which is specifically as follows.

[0090] Step S401: pre-processing the crystal rod to be tested, and cutting the crystal rod to be tested into segments.

[0091] The pretreatment of the crystal rod to be measured includes rolling the crystal rod to be measured.

[0092] The crystal rod to be tested is cut after rolling to obtain crystal rod segments to be tested.

[0093] Step S402: Select a silicon wafer to be tested.

[0094] In the present embodiment 1, a silicon wafer is selected from the crystal rod segment to be tested at intervals of 10 cm as the silicon wafer to be tested.

[0095] It should be noted that step S402 also includes pre-processing of the silicon wafer to be tested, which includes edge polishing, double-side grinding, chemical etching, double-side polishing and cleaning of the silicon wafer to be tested, thereby completing the pre-processing of the silicon wafer to be tested.

[0096] Step S403: Obtain the thickness and the first curvature radius of the silicon wafer to be tested.

[0097] In step S403, a silicon wafer topography measuring instrument is used to measure the topography of the silicon wafer to be measured to obtain the thickness of the silicon wafer to be measured. t s The first curvature radius is 740 μm R i It is 14518.18m.

[0098] Step S404: performing a deposition process.

[0099] In step S404, a silicon dioxide layer with a thickness of 400 nm is deposited on the surface of the silicon wafer to be tested by chemical vapor deposition, wherein the deposition temperature is 500°C.

[0100] After the deposition process, the SC1+SC2 solution combination is used for cleaning. It is understandable that since the material of the thin film layer is silicon dioxide, the step of cleaning with HF solution is omitted during cleaning, and only the SC1+SC2 solution combination is used to clean the silicon wafer to be tested after the deposition process.

[0101] Step S405 , obtaining a second radius of curvature of the silicon wafer to be tested after the deposition process is performed.

[0102] 3 hours after cleaning, the silicon wafer to be tested after the deposition process is measured using a silicon wafer topography measuring instrument to obtain the second curvature radius R f It is 3526.05m.

[0103] Step S406: Obtain mechanical parameters of the silicon wafer to be tested.

[0104] In step S406, the mechanical parameter of the silicon wafer to be tested is obtained according to the following calculation formula, which is about 233 GPa. Among them, the stress coefficient is 27410.55 (GPa·μm 2 ) / m.

[0105]

[0106] Step S407: performing a grade determination on the silicon wafer to be tested.

[0107] The mechanical parameters of the silicon wafer to be tested obtained in step S406 are 233 GPa, which is greater than 230 GPa. Therefore, the silicon wafer to be tested is a first-level silicon wafer.

[0108] Step S408: According to the result of the grade determination of the silicon wafer to be tested, the grade of the crystal rod segment to be tested is determined.

[0109] According to the grade determination result of the silicon wafer to be tested in step S407, it can be determined that the crystal rod segment to be tested is a first-class crystal rod, so the multiple silicon wafers cut from the crystal rod segment to be tested are all suitable for the composite process environment of high temperature and force load.

[0110] Example 2

[0111] like Figure 5 As shown, a method for detecting a polished silicon wafer is shown, which is specifically as follows.

[0112] Step S501, selecting a silicon wafer to be tested.

[0113] In this embodiment 2, a silicon wafer in the middle position is selected from 50 silicon wafers that have been polished to be selected as the silicon wafer to be tested.

[0114] Step S502: Obtain the thickness and the first curvature radius of the silicon wafer to be tested.

[0115] In step S502, a silicon wafer topography measuring instrument is used to measure the topography of the silicon wafer to be measured to obtain the thickness of the silicon wafer to be measured. t s The first curvature radius is 775.3 μm. R i It is 12677.60m.

[0116] Step S503: performing a deposition process.

[0117] In step S503, a silicon dioxide layer with a thickness of 200 nm is deposited on the surface of the silicon wafer to be tested by chemical vapor deposition, wherein the deposition temperature is 500°C.

[0118] After the deposition process, the SC1+SC2 solution combination is used for cleaning. It is understandable that since the material of the thin film layer is silicon dioxide, the step of cleaning with HF solution is omitted during cleaning, and only the SC1+SC2 solution combination is used to clean the silicon wafer to be tested after the deposition process.

[0119] Step S504 , obtaining a second radius of curvature of the silicon wafer to be tested after the deposition process is performed.

[0120] 3 hours after cleaning, the silicon wafer to be tested after the deposition process is measured using a silicon wafer topography measuring instrument to obtain the second curvature radius R f It is 9430.89m.

[0121] Step S505: Obtain mechanical parameters of the silicon wafer to be tested.

[0122] In step S505, the mechanical parameter of the silicon wafer to be tested is obtained according to the following calculation formula, which is about 199 GPa. Among them, the stress coefficient is 3247.98 (GPa·μm 2 ) / m.

[0123]

[0124] Step S506: performing a grade determination on the silicon wafer to be tested.

[0125] The mechanical parameter of the silicon wafer to be tested obtained based on step S505 is 199 GPa, which is greater than 180 GPa but less than 230 GPa. Therefore, the silicon wafer to be tested is a secondary silicon wafer, which can be applied to the composite process environment of high temperature and force load.

[0126] Example 3

[0127] like Figure 6 As shown, a method for detecting epitaxial silicon wafers is shown, which is specifically as follows.

[0128] It should be noted that the epitaxial silicon wafer in the present embodiment 3 refers to a silicon wafer to be tested which is prepared by depositing a thin film layer on the surface of the silicon wafer to be tested through a deposition process with the silicon wafer to be tested as a substrate.

[0129] Step S601, obtaining the thickness and the first curvature radius of the silicon wafer to be tested.

[0130] In step S601, a silicon wafer topography measuring instrument is used to measure the topography of the silicon wafer to be measured to obtain the thickness of the silicon wafer to be measured. t s The first curvature radius is 775.9 μm. R i It is 13231.13m.

[0131] Step S602: performing a deposition process.

[0132] In step S602, a silicon dioxide layer with a thickness of 600 nm is deposited on the surface of the silicon wafer to be tested by chemical vapor deposition, wherein the deposition temperature is 500°C.

[0133] After the deposition process, the SC1+SC2 solution combination is used for cleaning. It is understandable that since the material of the thin film layer is silicon dioxide, the step of cleaning with HF solution is omitted during cleaning, and only the SC1+SC2 solution combination is used to clean the silicon wafer to be tested after the deposition process.

[0134] Step S603 , obtaining a second radius of curvature of the silicon wafer to be tested after the deposition process is performed.

[0135] 4 hours after cleaning, the silicon wafer to be tested after the deposition process is measured using a silicon wafer topography measuring instrument to obtain the second curvature radius. R f It is 1613.94m.

[0136] Step S604: Obtain mechanical parameters of the silicon wafer to be tested.

[0137] In step S604, the mechanical parameter of the silicon wafer to be tested is obtained according to the following calculation formula, which is about 235.82 GPa. Among them, the stress coefficient is 77234.70 (GPa·μm 2 ) / m.

[0138]

[0139] Step S605: Determine the level of the epitaxial silicon wafer according to the mechanical parameters of the silicon wafer to be tested.

[0140] The mechanical parameter of the silicon wafer to be tested obtained based on step S604 is 235.82 GPa, which is greater than 230 GPa, thus indicating that the epitaxial silicon wafer is suitable for a composite process environment of high temperature and force load.

[0141] Example 4

[0142] The detection method process steps in this embodiment 4 are the same as the detection method process steps in embodiment 3, as shown below.

[0143] It should be noted that the epitaxial silicon wafer in the present embodiment 3 refers to a silicon wafer to be tested which is prepared by depositing a thin film layer on the surface of the silicon wafer to be tested through a deposition process with the silicon wafer to be tested as a substrate.

[0144] Step S601, obtaining the thickness and the first curvature radius of the silicon wafer to be tested.

[0145] In step S601, a silicon wafer topography measuring instrument is used to measure the topography of the silicon wafer to be measured to obtain the thickness of the silicon wafer to be measured. t s The first curvature radius is 775.12 μm. R i It is 15248.71m.

[0146] Step S602: performing a deposition process.

[0147] In step S602, a silicon layer with a thickness of 5400 nm is deposited on the surface of the silicon wafer to be tested by chemical vapor deposition, wherein the deposition temperature is 900°C.

[0148] After the deposition process, a HF+SC1+SC2 solution combination is used for cleaning.

[0149] Step S603 , obtaining a second radius of curvature of the silicon wafer to be tested after the deposition process is performed.

[0150] 5 hours after cleaning, the silicon wafer to be tested after the deposition process is measured using a silicon wafer topography measuring instrument to obtain the second curvature radius R f It is 1958.47m.

[0151] Step S604: Obtain mechanical parameters of the silicon wafer to be tested.

[0152] In step S604, the mechanical parameter of the silicon wafer to be tested is obtained according to the following calculation formula, which is about 234 GPa. Among them, the stress coefficient is 62473.40 (GPa·μm 2 ) / m.

[0153]

[0154] Step S605: Determine the level of the epitaxial silicon wafer according to the mechanical parameters of the silicon wafer to be tested.

[0155] The mechanical parameter of the silicon wafer to be tested obtained in step S604 is 234 GPa, which is greater than 230 GPa, thus indicating that the epitaxial silicon wafer is suitable for a composite process environment of high temperature and force load.

[0156] Comparative Example 1

[0157] The detection method process steps in this comparative example 1 are the same as the detection method process steps in Example 2. Figure 5 shown.

[0158] Step S501, selecting a silicon wafer to be tested.

[0159] In this comparative example 1, a silicon wafer in the middle position is selected from 50 silicon wafers that have been polished to be selected as the silicon wafer to be tested.

[0160] Step S502: Obtain the thickness and the first curvature radius of the silicon wafer to be tested.

[0161] In step S502, a silicon wafer topography measuring instrument is used to measure the topography of the silicon wafer to be measured to obtain the thickness of the silicon wafer to be measured. t s The first curvature radius is 775.3 μm. R i It is 12840.38m.

[0162] Step S503: performing a deposition process.

[0163] In step S503, a silicon dioxide layer with a thickness of 100 nm is deposited on the surface of the silicon wafer to be tested by chemical vapor deposition, wherein the deposition temperature is 500°C.

[0164] After the deposition process, the SC1+SC2 solution combination is used for cleaning. It is understandable that since the material of the thin film layer is silicon dioxide, the step of cleaning with HF solution is omitted during cleaning, and only the SC1+SC2 solution combination is used to clean the silicon wafer to be tested after the deposition process.

[0165] Step S504 , obtaining a second radius of curvature of the silicon wafer to be tested after the deposition process is performed.

[0166] 3 hours after cleaning, the silicon wafer to be tested after the deposition process is measured using a silicon wafer topography measuring instrument to obtain the second curvature radius R f It is 9430.89m.

[0167] Step S505: Obtain mechanical parameters of the silicon wafer to be tested.

[0168] In step S505, the mechanical parameter of the silicon wafer to be tested is obtained according to the following calculation formula, which is about 151.76 GPa. Among them, the stress coefficient is 2568.42 (GPa·μm 2 ) / m.

[0169]

[0170] Step S506: performing a grade determination on the silicon wafer to be tested.

[0171] The mechanical parameter of the silicon wafer to be tested obtained based on step S505 is 151.76 GPa, which is less than 180 GPa. Therefore, the silicon wafer to be tested is a third-grade silicon wafer, and the silicon wafer to be tested cannot be applied to the composite process environment of high temperature and force load.

[0172] It should be noted that the technical solutions described in the embodiments of the present disclosure can be combined arbitrarily without conflict.

[0173] The above is only a specific embodiment of the present disclosure, but the protection scope of the present disclosure is not limited thereto. Any person skilled in the art who is familiar with the technical field can easily think of changes or substitutions within the technical scope disclosed in the present disclosure, which should be included in the protection scope of the present disclosure. Therefore, the protection scope of the present disclosure should be based on the protection scope of the claims.

Claims

1. A method for detecting a silicon wafer, characterized in that: The detection method comprises: A thin film layer is deposited on the surface of the silicon wafer to be tested through a deposition process; Based on the thickness and the first curvature radius of the silicon wafer to be tested before the deposition process is performed, the second curvature radius of the silicon wafer to be tested after the deposition process is performed, and the stress coefficient corresponding to the deposition process, the mechanical parameters of the silicon wafer to be tested are obtained; wherein the mechanical parameters are used to characterize the mechanical strength of the silicon wafer to be tested, and ,in represents the mechanical parameters, represents the Young's modulus of the silicon wafer to be tested, represents the Poisson's ratio of the silicon wafer to be tested; the stress coefficient is the product of the mechanical stress corresponding to the thin film layer and the thickness of the thin film layer; Based on the mechanical parameters of the silicon wafer to be tested, performing a level determination on the silicon wafer to be tested; Wherein, based on the thickness and the first curvature radius of the silicon wafer to be tested before the deposition process is performed, the second curvature radius of the silicon wafer to be tested after the deposition process is performed, and the stress coefficient corresponding to the deposition process, the mechanical parameters of the silicon wafer to be tested are obtained, including: Based on the first radius of curvature and the second radius of curvature, obtaining a curvature change of the silicon wafer to be tested after performing the deposition process; Based on the thickness of the silicon wafer to be tested, the curvature change and the stress coefficient, the mechanical parameters of the silicon wafer to be tested are obtained; wherein the mechanical parameters are the stress coefficient divided by the product of the square of the thickness of the silicon wafer to be tested and the curvature change.

2. The detection method according to claim 1, characterized in that: The deposition process includes a deposition temperature of 450°C to 1000°C.

3. The detection method according to claim 2, characterized in that: The thickness of the thin film layer is in the range of 150 nm to 6000 nm.

4. The detection method according to claim 2, characterized in that: The material of the thin film layer includes silicon or a silicon-containing compound.

5. The detection method according to claim 1, characterized in that: The step of determining the level of the silicon wafer to be tested based on the mechanical parameters of the silicon wafer to be tested comprises: When the mechanical parameter of the silicon wafer to be tested is greater than a preset first target parameter, determining that the silicon wafer to be tested is a first-level silicon wafer; When the mechanical parameter of the silicon wafer to be tested is greater than a preset second target parameter and less than the first target parameter, the silicon wafer to be tested is determined to be a secondary silicon wafer; wherein the second target parameter is less than the first target parameter; When the mechanical parameter of the silicon wafer to be tested is less than the second target parameter, it is determined that the silicon wafer to be tested is a third-level silicon wafer.

6. The detection method according to claim 1, characterized in that: Before performing the deposition process, the detection method further includes: The crystal rod segment cut from the crystal rod to be tested is used as the crystal rod segment to be tested; At least one silicon wafer among the multiple silicon wafers cut from the crystal rod segment to be tested is used as the silicon wafer to be tested.

7. The detection method according to claim 6, characterized in that: After the level of the silicon wafer to be tested is determined, the detection method further includes: The level of the silicon wafer to be tested is determined based on the level of the silicon wafer to be tested.

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