Methods, apparatus, devices, and media for detecting transition region thickness of an epitaxial wafer

Abstract

The present disclosure provides a method, device, equipment and medium for detecting the thickness of a transition region of an epitaxial wafer, the method comprising: providing an epitaxial wafer; measuring a material mechanical property parameter along a depth direction at a sampling point on a front surface of the epitaxial wafer; and determining the thickness of a transition region between an epitaxial layer and a substrate of the epitaxial wafer based on the material mechanical property parameter along the depth direction at the sampling point.

Description

Technical Field

[0001] This disclosure relates to the field of semiconductor inspection technology, and in particular to a method, apparatus, device and medium for inspecting the thickness of the transition region of an epitaxial wafer. Background Technology

[0002] Epitaxial wafers typically possess excellent characteristics such as perfect crystallization without native crystal defects, precise controllability and thickness of epitaxial layers, and adjustable transition regions. Their epitaxial layers are widely used in the fabrication of integrated circuits and discrete devices, and can meet the requirements for producing power MOSFETs, insulated gate bipolar transistors, Schottky diodes, microprocessors, charge-coupled devices, and flash memory.

[0003] Generally, epitaxial wafers are fabricated using heavily arsenic-doped, heavily phosphorus-doped, heavily antimony-doped, or heavily boron-doped silicon polished wafers as substrates, and a lightly doped epitaxial layer is deposited on the substrate surface using a vapor deposition process. Between the substrate and the epitaxial layer, there exists a transition region, the thickness of which directly affects key parameters of the subsequently manufactured semiconductor devices, such as breakdown voltage, forward voltage drop, reverse voltage drop, and reverse recovery time.

[0004] Currently, the method for measuring the thickness of the transition region is to detect the resistance difference between the substrate and the epitaxial layer. The detection process requires processes such as wafer splitting, bonding, polishing, and etching, which are complicated and can damage the wafer. Summary of the Invention

[0005] This disclosure provides a method, apparatus, device, and medium for detecting the thickness of the transition region of an epitaxial wafer; it can avoid damaging the wafer, reduce processing complexity, and save testing resources.

[0006] The technical solution disclosed herein is implemented as follows:

[0007] In a first aspect, this disclosure provides a method for detecting the thickness of the transition region of an epitaxial wafer, the method comprising:

[0008] An epitaxial wafer is provided, wherein the doping concentrations of the substrate and the epitaxial layer of the epitaxial wafer are different;

[0009] For sampling points on the positive surface of the epitaxial wafer, measure the material mechanical properties along the depth direction at the sampling points;

[0010] The thickness of the transition region between the epitaxial layer and the substrate of the epitaxial wafer is determined based on the material mechanical properties along the depth direction at the sampling point.

[0011] Secondly, this disclosure provides an apparatus for detecting the thickness of the transition region of an epitaxial wafer, the apparatus comprising: a measuring unit and a determining unit; wherein,

[0012] The measuring unit is configured to measure the material mechanical properties along the depth direction at sampling points on the front surface of the epitaxial wafer; the doping concentrations of the substrate and the epitaxial layer of the epitaxial wafer are different.

[0013] The determining unit is configured to determine the thickness of the transition region between the epitaxial layer and the substrate of the epitaxial wafer based on the material mechanical property parameters along the depth direction at the sampling point.

[0014] Thirdly, this disclosure provides a computing device including a processor and a memory; the processor is configured to execute instructions stored in the memory to implement the method for detecting the thickness of a transition region of an epitaxial wafer as described in the first aspect.

[0015] Fourthly, this disclosure provides a computer-readable storage medium storing at least one instruction that is executed by a processor to implement the method for detecting the thickness of a transition region of an epitaxial wafer as described in the first aspect.

[0016] This disclosure provides a method, apparatus, device, and medium for detecting the thickness of the transition region of an epitaxial wafer; it utilizes the difference in mechanical properties to characterize the material property differences, and determines the thickness of the transition region of the epitaxial wafer based on the variation curve of the material's mechanical property parameters along the depth direction. This eliminates the need for excessive pre-operations on the epitaxial wafer before detection, reducing processing complexity and saving testing resources. Attached Figure Description

[0017] Figure 1 This is a schematic cross-sectional view of an exemplary epitaxial wafer provided in this disclosure.

[0018] Figure 2 This is a schematic flowchart of a method for detecting the thickness of the transition region of an epitaxial wafer, as provided in this disclosure.

[0019] Figure 3 (A) is a Young's modulus curve along the depth direction provided in this disclosure.

[0020] Figure 3 (B) is a hardness curve along the depth direction provided in this disclosure.

[0021] Figure 4 This is a schematic flowchart of another method for detecting the thickness of the transition region of an epitaxial wafer provided in this disclosure.

[0022] Figure 5 This is a schematic diagram showing the distribution of sampling points provided in this disclosure.

[0023] Figure 6 This is another Young's modulus curve along the depth direction provided in this disclosure.

[0024] Figure 7 This is a schematic diagram of an apparatus for detecting the thickness of the transition region of an epitaxial wafer, as provided in this disclosure.

[0025] Figure 8 This is a schematic diagram of another device for detecting the thickness of the transition region of an epitaxial wafer, as provided in this disclosure.

[0026] Figure 9 This is a schematic diagram of the structure of a computing device provided in this disclosure. Detailed Implementation

[0027] The technical solutions in this disclosure will now be clearly and completely described with reference to the accompanying drawings.

[0028] Figure 1 This is a schematic cross-sectional view of an exemplary epitaxial wafer applicable to the technical solutions disclosed herein. Figure 1 In this embodiment, the epitaxial wafer 1 consists of, from bottom to top, a substrate 11, a transition region 12 between the substrate 11 and the epitaxial layer 13, and the epitaxial layer 13. In this disclosure, the substrate 11 is typically doped with elements such as arsenic, phosphorus, antimony, or boron at a high concentration; in some cases, this substrate 11 may also be referred to as a heavily doped substrate. The epitaxial layer 13 is doped with elements such as arsenic, phosphorus, antimony, or boron at a lower concentration relative to the substrate 11; in some cases, the epitaxial layer 13 may also be referred to as a lightly doped epitaxial layer. The doping concentration of the transition region 12 is greater than that of the epitaxial layer 13 but less than that of the substrate 11. Figure 1 In this study, the difference in doping concentration between the substrate 11, the transition region 12, and the epitaxial layer 13 is characterized by the density variation of the filling points.

[0029] Due to differences in doping concentration, the substrate 11, transition region 12, and epitaxial layer 13 will exhibit differences in physical properties. These differences are most directly reflected in electrical parameters such as resistivity. Based on this, related solutions can determine the thickness of the transition region by detecting differences in resistivity. However, in practice, these solutions require pre-processing of the epitaxial wafer, including dicing, bonding, polishing, and etching, leading to a complex processing flow and increased processing complexity.

[0030] The inventors discovered that the differences in physical properties of the substrate 11, transition region 12, and epitaxial layer 13 of epitaxial wafer 1 can also be reflected through differences in mechanical properties. Based on this, this disclosure aims to provide a method for detecting the thickness of the transition region of an epitaxial wafer, measuring the thickness of the transition region based on differences in mechanical properties, avoiding pre-processing of the epitaxial wafer such as cleaving, bonding, polishing, and etching, reducing processing complexity, and saving testing resources.

[0031] See Figure 2This disclosure illustrates a method for detecting the thickness of the transition region of an epitaxial wafer, the method comprising steps S201 to S203.

[0032] In step S201, an epitaxial wafer is provided.

[0033] In this disclosure, the substrate and the epitaxial layer of the epitaxial wafer have different doping concentrations.

[0034] In some examples, the epitaxial wafer can be exemplarily as follows: Figure 1 As shown, the substrate is a heavily doped substrate, and the epitaxial layer is a lightly doped epitaxial layer. In some examples, the substrate in the epitaxial wafer may be a lightly doped substrate, and the epitaxial layer may be a heavily doped epitaxial layer; this disclosure will not elaborate on this.

[0035] In step S202, for sampling points on the positive surface of the epitaxial wafer, the material mechanical property parameters along the depth direction at the sampling points are measured.

[0036] In this disclosure, combined with Figure 1 As shown, the front surface of the epitaxial wafer is also the front surface of the epitaxial layer. This surface is typically used for patterning to form devices during the semiconductor device manufacturing process. The surface opposite to this front surface is the back surface of the epitaxial wafer.

[0037] In some examples, sampling points can be uniformly selected on the front surface of the epitaxial wafer. For example, sampling points can be uniformly selected within the front surface of the epitaxial wafer in a Cartesian coordinate system centered at the center of the epitaxial wafer. Alternatively, sampling points can be uniformly selected within the front surface of the epitaxial wafer in polar coordinates with the center of the epitaxial wafer as the pole.

[0038] In some examples, sampling points are selected along a diameter defined on the front surface of the epitaxial wafer, based on a predetermined distance from the center of the epitaxial wafer. Furthermore, other means of selecting sampling points are also applicable to the technical solutions of this disclosure, and will not be elaborated upon here.

[0039] After selecting sampling points on the positive surface of the epitaxial wafer using the above example, the mechanical property parameters along the depth direction at each sampling point can be measured using methods that do not require material decomposition. In this disclosure, the measurement method can be the continuous stiffness method of nanoindentation, and the measured mechanical property parameters can, exemplarily, be Young's modulus or hardness data. Specifically, the epitaxial wafer is placed and fixed on the test platform of the nanoindentation instrument, and the test parameters of the test platform are adjusted as follows: loading speed: 50 nN / s, vibration frequency of Continuous Stiffness Measurement (CSM): 45 Hz, vibration amplitude: 20 nm, maximum indentation depth: 600 nm, unloading rate: 0.1 mN / s, holding time: 10 seconds. The Young's modulus or hardness of each sampling point within a 600 nm depth range is measured. For example, the Young's modulus curve along the depth direction obtained for a sampling point is as follows: Figure 3 As shown in (A), in Figure 3 In (A), the horizontal axis represents the depth value in nm, and the vertical axis represents the Young's modulus value corresponding to the depth value in GPa. In other examples, the hardness curve along the depth direction obtained from measuring a sampling point is as follows: Figure 3 As shown in (B), in Figure 3 In (B), the horizontal axis represents the depth value in nm, and the vertical axis represents the hardness data value corresponding to the depth value in GPa.

[0040] In step S203, the thickness of the transition region between the epitaxial layer of the epitaxial wafer and the substrate is determined based on the material mechanical property parameters along the depth direction at the sampling point.

[0041] In this disclosure, based on the aforementioned finding that the differences in physical properties of the substrate, transition region, and epitaxial layer are manifested through differences in mechanical properties, for mechanical performance parameters along the depth direction, such as... Figure 3 The Young's modulus shown in (A), or Figure 3 The hardness data shown in (B) exhibits significant differences in measurement values ​​across the epitaxial layer, transition region, and substrate due to variations in physical properties. For example, the hardness data obtained in step S202 above... Figure 3 As shown in (A), the Young's modulus curve along the depth direction at a sampling point on the epitaxial wafer reveals that, in the depth range from 0 to approximately 400 nm, the Young's modulus oscillates slightly around a reference of 152 GPa; in the depth range from approximately 470 nm to 600 nm, the Young's modulus oscillates slightly around a reference of 130 GPa; and in the depth range from approximately 400 nm to approximately 470 nm, the Young's modulus exhibits a significant change, decreasing approximately linearly from 152 GPa to 130 GPa. Figure 3 As shown in curve (A), the depth range from 0 to approximately 400 nm represents the Young's modulus region of the epitaxial layer, and the corresponding depth range can be considered the thickness of the epitaxial layer. The depth range from approximately 470 nm to 600 nm represents the Young's modulus region of the substrate, and the corresponding depth range can be considered the thickness of the substrate. The thickness range of the transition region is from 400 nm to 470 nm; that is, the depth from this range is the thickness of the transition region. In other examples, Figure 3 As shown in (B), the hardness curve along the depth direction of a sampling point on the epitaxial wafer shows that in the depth range from 0 to about 400 nm, the hardness oscillates slightly with a reference of 10.5 GPa. In the depth range from about 470 nm to 600 nm, the hardness oscillates slightly with a reference of 10 GPa. However, in the depth range from about 400 nm to about 470 nm, the hardness changes and decreases approximately linearly from 10.5 GPa to 10 GPa.

[0042] In some examples, the thickness of the transition region between the epitaxial layer and the substrate at each sampling point on the positive surface of the epitaxial wafer can be determined based on the Young's modulus or hardness along the depth direction at each sampling point. By summing the thicknesses of the transition regions at all sampling points according to their distribution on the positive surface of the epitaxial wafer, a surface plot representing the thickness of the transition region across the entire epitaxial wafer can be obtained. Figure 3 Comparing (A) and (B) in the figure, it can be found that in the depth range of approximately 400 nm to approximately 470 nm, the decrease in Young's modulus is significantly greater than the decrease in hardness. The curves show more intuitively that Young's modulus is more suitable for thickness measurement than hardness.

[0043] Through the above technical solution, this disclosure utilizes the difference in mechanical properties to characterize the difference in material properties. The thickness of the transition region of the epitaxial wafer is determined based on the change curve of material mechanical property parameters such as Young's modulus or hardness along the depth direction. This eliminates the need for excessive pre-operation of the epitaxial wafer before testing, reducing processing complexity and saving testing resources.

[0044] Based on the aforementioned technical solution, see Figure 4 This disclosure illustrates another method for detecting the thickness of the transition region of an epitaxial wafer, the method comprising steps S401 to S406.

[0045] In step S401, an epitaxial wafer is provided.

[0046] In this disclosure, as mentioned above Figure 2 Similar to the scheme shown, epitaxial wafers can be exemplarily as follows: Figure 1As shown, the substrate is a heavily doped substrate, and the epitaxial layer is a lightly doped epitaxial layer.

[0047] In step S402, multiple first measurement points are uniformly set at the center of the epitaxial wafer and at the edge of the epitaxial wafer.

[0048] In this disclosure, Figure 5 Taking the positive surface of the epitaxial wafer shown as an example, in Figure 5 In this invention, the center of the positive surface of the epitaxial wafer is set as O, and the edge of the epitaxial wafer is shown as a solid circle. First measurement points are set at a set interval angle on the edge of the epitaxial wafer. In this invention, the number of first measurement points is 4, which are respectively labeled as R1, R2, R3 and R4.

[0049] In step S403, multiple second measurement points are uniformly arranged on an auxiliary circle on the surface of the epitaxial wafer.

[0050] See also in this disclosure. Figure 5 The auxiliary circle, as shown by the dashed circle, has its center O as the center of the epitaxial wafer and its radius as half the radius of the epitaxial wafer. On this auxiliary circle, second measurement points are also set at the same angular intervals as the first measurement points. In this disclosure, the number of second measurement points is also four, labeled R1-1, R2-1, R3-1, and R4-1. Exemplarily, each first measurement point has a corresponding second measurement point located on the same radial line. In this disclosure, R1 and R1-1 are on the same radial line, R2 and R2-1 are on the same radial line, R3 and R3-1 are on the same radial line, and R4 and R4-1 are on the same radial line.

[0051] In step S404, the center of the epitaxial wafer, the first measurement point, and the second measurement point are used as sampling points. Based on the continuous stiffness method of nanoindentation, the Young's modulus along the depth direction at each sampling point is measured.

[0052] In this disclosure, examples of using Young's modulus as a material mechanical property parameter are further illustrated below. Figure 5 As shown, the center O of the epitaxial wafer, the first measurement points R1, R2, R3, and R4, and the second measurement points R1-1, R2-1, R3-1, and R4-1 are used as sampling points. A continuous stiffness method using nanoindentation is applied to each of these sampling points to obtain the Young's modulus curve along the depth direction at each sampling point. The variation of Young's modulus with depth in this curve is exemplarily illustrated with... Figure 3 The curve shown in (A) is similar.

[0053] In step S405, the thickness of the transition region between the epitaxial layer and the substrate at each sampling point on the positive surface of the epitaxial wafer is obtained based on the Young's modulus along the depth direction at each sampling point.

[0054] In this disclosure, the Young's modulus curve along the depth direction at each sampling point is compared with... Figure 3 The curves in (A) are similar, such as Figure 6 As shown. In some examples, from the Young's modulus curve along the depth direction at each sampling point, the Young's modulus zone of the epitaxial layer and the Young's modulus zone of the substrate can be analyzed based on the amplitude of the oscillation of the curve, and the thickness between the Young's modulus zone of the epitaxial layer and the Young's modulus zone of the substrate is determined as the thickness of the transition region.

[0055] Specifically, in the above example, determining the thickness of the transition region as the thickness between the Young's modulus region of the epitaxial layer and the Young's modulus region of the substrate includes:

[0056] Obtain the difference between the Young's modulus region of the epitaxial layer and the Young's modulus region of the substrate;

[0057] In the Young's modulus curve along the depth direction at the sampling point, the starting point of the transition region is 5% of the difference, and the ending point of the transition region is 95% of the difference. The thickness of the transition region is obtained based on the depth values ​​of the starting point and the ending point of the transition region.

[0058] In detail, the curves in both the Young's modulus region of the epitaxial layer and the Young's modulus region of the substrate oscillate slightly around a reference Young's modulus value. After obtaining the reference Young's modulus values ​​for the Young's modulus regions of the epitaxial layer and the substrate respectively based on the slight oscillation curves of these two regions, the difference between the reference Young's modulus values ​​of the two regions is obtained. This difference represents the change in Young's modulus in the transition region.

[0059] In response to the above changes, in the Young's modulus curve, this disclosure uses 5% of the difference as the starting point of the transition region and 95% of the difference as the ending point of the transition region. The difference in depth between the starting point and the ending point is the thickness of the transition region.

[0060] In step S406, the thickness of the transition region between the epitaxial layer and the substrate of the epitaxial wafer is obtained based on the thickness of the transition region between the epitaxial layer and the substrate at each sampling point.

[0061] In this disclosure, in conjunction with the foregoing Figure 5The thickness of the transition region at each of the nine sampling points shown is obtained according to step S405. The thickness values ​​of the transition region at each of the nine sampling points can be combined to obtain the thickness value of the transition region between the epitaxial layer and the substrate of the epitaxial wafer. For example, the average thickness value of the transition region at these nine sampling points can be used as the thickness value of the transition region of the entire epitaxial wafer.

[0062] Understandably, those skilled in the art can also use hardness as a material mechanical property parameter for implementation. Figure 4 The technical solutions shown in this disclosure will not be described in detail here.

[0063] In addition, the thickness values ​​of the transition region at these 9 sampling points can be used to obtain the deviation of the transition region on the epitaxial wafer surface at different radii.

[0064] Specifically, in epitaxial wafers Deviation in the transition region at the radius As shown in Equation 1 below:

[0065] (1)

[0066] in, This indicates the thickness of the transition region at R1-1. This indicates the thickness of the transition region at R2-1. This indicates the thickness of the transition region at R3-1. This indicates the thickness of the transition region at R4-1. This indicates the thickness of the transition region at the center O of the epitaxial wafer.

[0067] At the radius of the epitaxial wafer, the deviation of the transition region As shown in Equation 2 below:

[0068] (2)

[0069] in, This indicates the thickness of the transition region at R1. This indicates the thickness of the transition region at R2. This indicates the thickness of the transition region at R3. This indicates the thickness of the transition region at R4. This indicates the thickness of the transition region at the center O of the epitaxial wafer.

[0070] For example, the thicknesses of the epitaxial layer (Flat Zone) and the transition region (Transition) at the aforementioned nine sampling points according to the technical solution are shown in columns 2 and 3 of Table 1, respectively. Furthermore, for these nine sampling points, the thicknesses of the epitaxial layer and the transition region were measured using Spreading Resistance Profile (SRP) for comparison, as shown in columns 4 and 5 of Table 1, respectively. In Table 1, the unit of thickness is nm.

[0071]

[0072] Table 1

[0073] Based on the data shown in Table 1, the values ​​obtained from Equations 1 and 2 above can be obtained for the epitaxial wafer. Deviation in the transition region at the radius The deviation in the transition region is 7.61% at the radius of the epitaxial wafer. The thickness is 1.28%. Furthermore, compared to the thickness of the epitaxial layer (Flat Zone by SPR) and the transition region (Transition by SPR) measured using the SRP method, the thickness values ​​measured by the present disclosure are quite close. It can be seen that the present disclosure's concept of measuring the thickness of the transition region based on differences in mechanical properties can also accurately measure the thickness of the epitaxial layer and the transition region. Moreover, compared to methods that measure electrical parameters, it avoids pre-processing of the epitaxial wafer, such as cleaving, bonding, polishing, and etching, reducing processing complexity and saving testing resources.

[0074] Based on the same inventive concept as the aforementioned technical solution, see [link to inventive concept]. Figure 7 This disclosure illustrates an apparatus 70 for detecting the thickness of a transition region in an epitaxial wafer, comprising: a measuring unit 71 and a determining unit 72; wherein,

[0075] The measuring unit 71 is configured to measure material mechanical properties along the depth direction at sampling points on the front surface of the epitaxial wafer; the doping concentrations of the substrate and the epitaxial layer of the epitaxial wafer are different.

[0076] The determining unit 72 is configured to determine the thickness of the transition region between the epitaxial layer of the epitaxial wafer and the substrate based on the material mechanical property parameters along the depth direction at the sampling point.

[0077] See in some examples Figure 8The device 70 further includes a setting part 73, configured to uniformly set a plurality of first measurement points at the center of the epitaxial wafer along the edge of the epitaxial wafer; and uniformly set a plurality of second measurement points on an auxiliary circle on the surface of the epitaxial wafer; wherein the auxiliary circle is centered at the center and has a radius of half the radius of the epitaxial wafer.

[0078] Accordingly, the measuring unit 71 is configured to:

[0079] Using the center of the epitaxial wafer, the first measurement point, and the second measurement point as sampling points, the Young's modulus or hardness along the depth direction at each sampling point is measured based on the continuous stiffness method of nanoindentation.

[0080] In some examples, the setting unit 73 is configured to uniformly select a plurality of sampling points on the positive surface of the epitaxial wafer;

[0081] Accordingly, the measuring unit 71 is configured to measure the Young's modulus or hardness along the depth direction at each sampling point using a continuous stiffness method based on nanoindentation.

[0082] In some examples, the test parameters for the continuous stiffness method of the nanoindentation are:

[0083] The loading speed was 50 nN / s, the vibration frequency of the continuous rigidity test CSM was 45 Hz, the vibration amplitude was 20 nm, the maximum indentation depth was 600 nm, the unloading rate was 0.1 mN / s, and the holding time was 10 seconds.

[0084] In some examples, the determining unit 72 is configured to:

[0085] Based on the material mechanical property parameters along the depth direction at each sampling point, the thickness of the transition region between the epitaxial layer and the substrate at each sampling point on the front surface of the epitaxial wafer is obtained.

[0086] The thickness of the transition region between the epitaxial layer and the substrate of the epitaxial wafer is obtained based on the thickness of the transition region between the epitaxial layer and the substrate at each sampling point.

[0087] In some examples, the determining unit 72 is configured to:

[0088] For each sampling point, the thickness of the transition region is determined from the Young's modulus curve along the depth direction at the sampling point, between the Young's modulus segment of the epitaxial layer and the Young's modulus segment of the substrate.

[0089] Alternatively, for each sampling point, the thickness of the transition region can be determined from the hardness curve along the depth direction at that sampling point, specifically the thickness between the hardness range of the epitaxial layer and the hardness range of the substrate.

[0090] In some examples, the determining unit 72 is configured to:

[0091] Obtain the difference between the Young's modulus region of the epitaxial layer and the Young's modulus region of the substrate;

[0092] In the Young's modulus curve along the depth direction at the sampling point, the starting point of the transition region is taken as 5% of the difference, and the ending point of the transition region is taken as 95% of the difference. The thickness of the transition region is obtained based on the depth value of the starting point and the depth value of the ending point of the transition region.

[0093] In some examples, the determining unit 72 is configured to:

[0094] Obtain the difference between the hardness range of the epitaxial layer and the hardness range of the substrate;

[0095] In the hardness curve along the depth direction at the sampling point, the starting point of the transition region is taken as 5% of the difference, and the ending point of the transition region is taken as 95% of the difference. The thickness of the transition region is obtained based on the depth value of the starting point and the depth value of the ending point of the transition region.

[0096] Please refer to Figure 9 This illustration shows a structural block diagram of a computing device provided in an exemplary embodiment of the present disclosure. In some examples, the computing device 90 can be at least one of devices such as a smartphone, smartwatch, desktop computer, laptop, virtual reality terminal, augmented reality terminal, wireless terminal, and laptop computer. The computing device 90 has communication functions and can access wired or wireless networks. The computing device 90 can refer to one of a plurality of terminals, and those skilled in the art will understand that the number of such terminals can be more or less. In some examples, the computing device 90 can receive data based on the accessed wired or wireless network. It is understood that the computing device 90 undertakes the calculation and processing work of the technical solution of the present disclosure, and the present disclosure does not limit it in this respect.

[0097] like Figure 9 As shown, the computing device in this disclosure may include one or more components such as a processor 910 and a memory 920.

[0098] Optionally, the processor 910 connects various parts within the computing device using various interfaces and lines, and performs various functions and processes data by running or executing instructions, programs, code sets, or instruction sets stored in the memory 920, and by calling data stored in the memory 920. Optionally, the processor 910 can be implemented using at least one hardware form of Digital Signal Processing (DSP), Field-Programmable Gate Array (FPGA), or Programmable Logic Array (PLA). The processor 910 can integrate one or a combination of several of the following: Central Processing Unit (CPU), Graphics Processing Unit (GPU), Neural-network Processing Unit (NPU), and baseband chip. Specifically, the CPU primarily handles the operating system, user interface, and applications; the GPU is responsible for rendering and drawing the content required for display on the touch screen; the NPU is used to implement Artificial Intelligence (AI) functions; and the baseband chip is used for wireless communication. It is understandable that the aforementioned baseband chip may not be integrated into the processor 910, but may be implemented using a separate chip.

[0099] The memory 920 may include random access memory (RAM) or read-only memory (ROM). Optionally, the memory 920 may include a non-transitory computer-readable storage medium. The memory 920 may be used to store instructions, programs, code, code sets, or instruction sets. The memory 920 may include a program storage area and a data storage area, wherein the program storage area may store instructions for implementing an operating system, instructions for at least one function (such as touch function, sound playback function, image playback function, etc.), instructions for implementing the various method embodiments described above, etc.; the data storage area may store data created according to the use of the computing device, etc.

[0100] In addition, those skilled in the art will understand that the structure of the computing device shown in the above figures does not constitute a limitation on the computing device. The computing device may include more or fewer components than shown, or combine certain components, or have different component arrangements. For example, the computing device may also include a display screen, camera assembly, microphone, speaker, radio frequency circuit, input unit, sensors (such as accelerometer, angular velocity sensor, light sensor, etc.), audio circuit, WiFi module, power supply, Bluetooth module, etc., which will not be described in detail here.

[0101] This disclosure also provides a computer-readable storage medium storing at least one instruction that is executed by a processor to implement the method for detecting the thickness of a transition region of an epitaxial wafer as described in the various embodiments above.

[0102] This disclosure also provides a computer program product including computer instructions stored in a computer-readable storage medium; a processor of a computing device reads the computer instructions from the computer-readable storage medium and executes the computer instructions, causing the computing device to perform the method for detecting the thickness of the transition region of an epitaxial wafer as described in the various embodiments above.

[0103] Those skilled in the art will recognize that the functions described in this disclosure in one or more of the examples above can be implemented using hardware, software, firmware, or any combination thereof. When implemented in software, these functions can be stored in a computer-readable medium or transmitted as one or more instructions or code on a computer-readable medium. Computer-readable media include computer storage media and communication media, wherein communication media include any medium that facilitates the transfer of a computer program from one place to another. Storage media can be any available medium accessible to a general-purpose or special-purpose computer.

[0104] It should be noted that the technical solutions described in this disclosure can be combined arbitrarily as long as they do not conflict.

[0105] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A method for detecting the thickness of the transition region of an epitaxial wafer, characterized in that, The method comprises: providing an epitaxial wafer, the substrate and the epitaxial layer of which have different doping concentrations; measuring the material mechanical property parameters along the depth direction at the sampling points on the front surface of the epitaxial wafer; based on the material mechanical property parameters along the depth direction at the sampling points, obtaining the thickness of the transition region between the epitaxial layer and the substrate at each sampling point on the front surface of the epitaxial wafer, the thickness of the transition region between the epitaxial layer and the substrate at each sampling point comprising the thickness between the material mechanical property parameter section of the epitaxial layer and the material mechanical property parameter section of the substrate, and the starting point of the transition region being the point at which the difference between the material mechanical property parameter of the epitaxial layer and the material mechanical property parameter of the substrate is 5%, and the ending point of the transition region being the point at which the difference between the material mechanical property parameter of the epitaxial layer and the material mechanical property parameter of the substrate is 95%, the material mechanical property parameters comprising the Young's modulus curve or the hardness curve; obtaining the thickness of the transition region between the epitaxial layer and the substrate of the epitaxial wafer according to the thickness of the transition region between the epitaxial layer and the substrate at each sampling point.

2. The method of claim 1, wherein, The method further comprises: uniformly arranging a plurality of first measurement points on the edge of the epitaxial wafer with the center of the epitaxial wafer as the center; uniformly arranging a plurality of second measurement points on the auxiliary circle on the surface of the epitaxial wafer, wherein the auxiliary circle has the center as the center and half of the radius of the epitaxial wafer as the radius; Correspondingly, the measurement of the material mechanical property parameters along the depth direction at the sampling points comprises: measuring the Young's modulus or the hardness along the depth direction at each sampling point based on the continuous stiffness method of nanoindentation with the center of the epitaxial wafer, the first measurement points and the second measurement points as the sampling points.

3. The method of claim 1, wherein, The method comprises: uniformly selecting a plurality of sampling points on the front surface of the epitaxial wafer; and correspondingly, the measurement of the Young's modulus along the depth direction at the sampling points comprises: measuring the Young's modulus or the hardness along the depth direction at each sampling point based on the continuous stiffness method of nanoindentation.

4. The method according to claim 2 or 3, characterized in that, The test parameters of the continuous stiffness method of nanoindentation are: the loading speed is 50 nN / s, the vibration frequency of the continuous stiffness measurement (CSM) is 45 Hz, the vibration amplitude is 20 nm, the maximum indentation depth is 600 nm, the unloading rate is 0.1 mN / s, and the holding time is 10 seconds.

5. The method of claim 1, wherein, The thickness between the Young's modulus section of the epitaxial layer and the Young's modulus section of the substrate is determined as the thickness of the transition region, comprising: obtaining the difference between the Young's modulus section of the epitaxial layer and the Young's modulus section of the substrate; in the Young's modulus curve along the depth direction at the sampling points, taking 5% of the difference as the starting point of the transition region and 95% of the difference as the ending point of the transition region, and obtaining the thickness of the transition region according to the depth value of the starting point of the transition region and the depth value of the ending point of the transition region.

6. The method of claim 1, wherein, The thickness between the hardness section of the epitaxial layer and the hardness section of the substrate is determined as the thickness of the transition region, comprising: obtaining the difference between the hardness section of the epitaxial layer and the hardness section of the substrate; in the hardness curve along the depth direction at the sampling point, the starting point of the transition region is 5% of the difference value, and the ending point of the transition region is 95% of the difference value, and the thickness of the transition region is obtained according to the depth value of the starting point of the transition region and the depth value of the ending point of the transition region.

7. An apparatus for detecting the thickness of the transition region of an epitaxial wafer, characterized in that, The device comprises a measuring unit and a determining unit, wherein, the measuring unit is configured to measure the material mechanical property parameters along the depth direction at the sampling points on the front surface of the epitaxial wafer, the doping concentrations of the substrate and the epitaxial layer of the epitaxial wafer being different; the determining unit is configured to obtain the thickness of the transition region between the epitaxial layer and the substrate at each sampling point on the front surface of the epitaxial wafer based on the material mechanical property parameters along the depth direction at the sampling points, respectively, the thickness of the transition region between the epitaxial layer and the substrate at each sampling point comprising the thickness between the section of the material mechanical property parameters of the epitaxial layer and the section of the material mechanical property parameters of the substrate, and the starting point of the transition region being the point of 5% of the difference between the material mechanical property parameters of the epitaxial layer and the material mechanical property parameters of the substrate at each sampling point, and the ending point of the transition region being the point of 95% of the difference between the material mechanical property parameters of the epitaxial layer and the material mechanical property parameters of the substrate at each sampling point; the material mechanical property parameters include Young's modulus curve or hardness curve; the thickness of the transition region between the epitaxial layer and the substrate of the epitaxial wafer is obtained according to the thickness of the transition region between the epitaxial layer and the substrate at each sampling point.

8. A computing device, comprising: The computing device comprises a processor and a memory; the processor is used to execute the instructions stored in the memory to realize the method for detecting the thickness of the transition region of the epitaxial wafer as claimed in any one of claims 1 to 6.

9. A computer-readable storage medium, characterized in that, The computer readable storage medium stores at least one instruction, the at least one instruction is used to be executed by the processor to realize the method for detecting the thickness of the transition region of the epitaxial wafer as claimed in any one of claims 1 to 6.

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