Method, device, equipment and medium for detecting thickness of transition region of epitaxial wafer

Abstract

The invention provides a method, device and equipment for detecting the thickness of a transition region of an epitaxial wafer and a medium. The method comprises the following steps: providing the epitaxial wafer; aiming at the sampling points on the front surface of the epitaxial wafer, measuring material mechanical property parameters at the sampling points along the depth direction; and determining the thickness of a 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 points.

Description

Technical Field

[0001] The present disclosure relates to the field of semiconductor detection technology, and in particular to a method, device, equipment and medium for detecting the thickness of a transition region of an epitaxial wafer. Background Art

[0002] Epitaxial wafers usually have excellent properties such as perfect crystallization without native crystal defects, precisely controllable resistivity and thickness of the epitaxial layer, and adjustable transition zone. Their epitaxial layers are widely used in the production of integrated circuits and discrete devices, and can meet the requirements of producing power field effect devices, insulated gate bipolar transistors, Schottky diodes, microprocessors, charge-coupled devices and flash memories.

[0003] Generally speaking, epitaxial wafers are processed with heavily doped arsenic, heavily doped phosphorus, heavily doped antimony, and heavily doped boron silicon polished wafers as substrates, and a lightly doped epitaxial layer is deposited on the substrate surface through a vapor deposition process. There is a transition region between the substrate and the epitaxial layer, and the thickness of this region directly affects the key parameters of the subsequent semiconductor devices, such as breakdown voltage, forward voltage drop, reverse voltage drop, and reverse recovery time.

[0004] The current method for measuring the thickness of the transition region is to detect the resistance difference between the substrate and the epitaxial layer. During the detection process, it is necessary to perform processes such as splitting, bonding, polishing and etching. The processing flow is complicated and may cause damage to the wafer. Summary of the invention

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

[0006] The technical solution of the present disclosure is achieved as follows: In a first aspect, the present disclosure provides a method for detecting the thickness of a transition region of an epitaxial wafer, the method comprising: Providing an epitaxial wafer, wherein the substrate and the epitaxial layer of the epitaxial wafer have different doping concentrations; For the sampling points on the front surface of the epitaxial wafer, the material mechanical property parameters along the depth direction at the sampling points are measured; The thickness of the transition region between the epitaxial layer and the substrate of the epitaxial wafer is determined based on the material mechanical property parameters along the depth direction at the sampling point.

[0007] In a second aspect, the present disclosure provides a device for detecting the thickness of a transition region of an epitaxial wafer, the device comprising: 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 substrate and the epitaxial layer of the epitaxial wafer have different doping concentrations; The determination unit is configured to determine the thickness of a transition region between an epitaxial layer and a substrate of the epitaxial wafer based on a material mechanical property parameter along a depth direction at a sampling point.

[0008] In a third aspect, the present disclosure provides a computing device comprising a processor and a memory; the processor is used 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.

[0009] In a fourth aspect, the present disclosure provides a computer-readable storage medium storing at least one instruction, wherein the at least one instruction is used to be 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.

[0010] The present disclosure provides a method, device, equipment and medium for detecting the thickness of the transition region of an epitaxial wafer; the difference in mechanical properties is used to characterize the difference in physical properties of materials, and the thickness of the transition region of the epitaxial wafer is determined according to the change curve of the material mechanical performance parameters along the depth direction. There is no need to perform too much pre-operation on the epitaxial wafer before detection, which reduces the processing complexity and saves testing resources. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Figure 1 A schematic cross-sectional view of an exemplary epitaxial wafer provided in the present disclosure.

[0012] Figure 2 A schematic flow chart of a method for detecting the thickness of a transition region of an epitaxial wafer provided in the present disclosure.

[0013] Figure 3 (A) is a Young's modulus curve along the depth direction provided by the present disclosure.

[0014] Figure 3 (B) is a hardness curve diagram along the depth direction provided by the present disclosure.

[0015] Figure 4 A schematic flow chart of another method for detecting the thickness of a transition region of an epitaxial wafer provided in the present disclosure.

[0016] Figure 5 A schematic diagram of the distribution of sampling points provided in the present disclosure.

[0017] Figure 6 Another Young's modulus graph along the depth direction is provided for the present disclosure.

[0018] Figure 7 A schematic diagram of the composition of a device for detecting the thickness of a transition region of an epitaxial wafer provided in the present invention.

[0019] Figure 8 A schematic diagram of another device for detecting the thickness of a transition region of an epitaxial wafer provided in the present disclosure.

[0020] Fig. 9 A schematic diagram of the structure of a computing device provided by the present disclosure. DETAILED DESCRIPTION

[0021] The technical solutions in the present disclosure will be described clearly and completely below in conjunction with the accompanying drawings in the present disclosure.

[0022] Figure 1 FIG. 1 is a cross-sectional schematic diagram of an exemplary epitaxial wafer applicable to the technical solution of the present disclosure. Figure 1 In the embodiment, the epitaxial wafer 1 includes, 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 the present disclosure, the substrate 11 is usually doped with arsenic, phosphorus, antimony, boron and other elements at a high concentration. In some cases, the substrate 11 can also be referred to as a heavily doped substrate. The epitaxial layer 13 is doped with arsenic, phosphorus, antimony, boron and other elements at a lower concentration than the substrate 11. In some cases, the epitaxial layer 13 can 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 and less than that of the substrate 11. Figure 1 In the embodiment, the difference between the doping concentrations of the substrate 11, the transition region 12 and the epitaxial layer 13 is characterized by the density variation of the filling points.

[0023] Due to the difference in doping concentration, there will be differences in physical properties between the substrate 11, the transition region 12 and the epitaxial layer 13. This difference is most intuitively reflected in electrical parameters such as resistivity. Based on this, the relevant scheme can determine the thickness of the transition region by detecting the difference in resistivity. However, during the implementation of the relevant scheme, the epitaxial wafer needs to be pre-processed by splitting, bonding, polishing and etching, which makes the processing flow complicated and increases the processing complexity.

[0024] The inventors found that the physical property differences of the substrate 11, transition region 12 and epitaxial layer 13 of the epitaxial wafer 1 can also be reflected by the differences in mechanical properties. Based on this, the present disclosure hopes to provide a solution for detecting the thickness of the transition region of the epitaxial wafer, measuring the thickness of the transition region based on the difference in mechanical properties, avoiding pre-splitting, bonding, polishing and etching of the epitaxial wafer, reducing the processing complexity and saving testing resources.

[0025] See also Figure 2 , which shows a method for detecting the thickness of a transition region of an epitaxial wafer provided by the present disclosure, the method comprising steps S201 to S203.

[0026] In step S201 , an epitaxial wafer is provided.

[0027] In the present disclosure, the doping concentrations of the substrate and the epitaxial layer of the epitaxial wafer are different.

[0028] In some examples, the epitaxial wafer may be exemplarily 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, which is not described in detail in this disclosure.

[0029] In step S202 , for sampling points on the front surface of the epitaxial wafer, material mechanical property parameters along the depth direction at the sampling points are measured.

[0030] In the present disclosure, Figure 1 As shown, the front surface of the epitaxial wafer is the front surface of the epitaxial layer, which is usually used for patterning to form a device during the semiconductor device manufacturing process. The surface opposite to the front surface is the back side of the epitaxial wafer.

[0031] In some examples, sampling points may be uniformly selected on the front surface of the epitaxial wafer. For example, in a rectangular coordinate system with the center of the epitaxial wafer as the center of the circle, sampling points are uniformly selected within the front surface of the epitaxial wafer. In addition, in a polar coordinate system with the center of the epitaxial wafer as the pole, sampling points are uniformly selected within the front surface of the epitaxial wafer.

[0032] In some examples, the sampling point is selected based on a set distance from the center of the epitaxial wafer according to a diameter of a set direction on the front surface of the epitaxial wafer. In addition, other means for implementing the selection of sampling points are applicable to the technical solution of the present disclosure and will not be described in detail here.

[0033] After selecting the sampling points on the front surface of the epitaxial wafer through the above example, the mechanical performance parameters along the depth direction at each sampling point can be measured by some mechanical performance parameter measurement methods that do not require the cracking of the material. In the present disclosure, the measurement method can be the continuous stiffness method of nanoindentation, and the measured mechanical performance parameters can be exemplarily 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 to: loading speed: 50 nN / s, continuous stiffness measurement (Continuous Stiffness Measurement, CSM) vibration frequency: 45 Hz, vibration amplitude: 20 nm, maximum indentation depth: 600nm, unloading rate: 0.1 mN / s, holding time is 10 seconds, and the Young's modulus or hardness of each sampling point within 600 nanometers in the depth direction is measured. For example, the Young's modulus curve along the depth direction measured for a sampling point is as follows: Figure 3(A) shows that 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 measured at a sampling point is as follows: Figure 3 (B) As shown 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.

[0034] 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.

[0035] In the present disclosure, based on the aforementioned finding that the physical property differences of the substrate, the transition region and the epitaxial layer are reflected by the differences in mechanical properties, for the mechanical performance parameters along the depth direction, such as Figure 3 (A) Young's modulus, or Figure 3 The hardness data shown in (B) has significant differences in the measured values ​​of the epitaxial layer, transition region and substrate due to the difference in physical properties. Figure 3 From the Young's modulus curve of a sampling point on the epitaxial wafer shown in (A) along the depth direction, it can be seen that in the depth range from 0 to about 400nm, the Young's modulus oscillates slightly with 152GPa as the reference, and in the depth range from about 470nm to 600nm, the Young's modulus oscillates slightly with 130GPa as the reference, and in the depth range from about 400nm to about 470nm, the Young's modulus changes significantly, decreasing linearly from 152GPa to 130GPa. Figure 3 From the curve of (A), it can be seen that the depth range from 0 to about 400nm represents the Young's modulus section of the epitaxial layer, and the depth range corresponding to this section can be considered as the thickness of the epitaxial layer. The depth range from about 470nm to 600nm represents the Young's modulus section of the substrate, and the depth range corresponding to this section can be considered as the thickness of the substrate. The thickness range of the transition region is the depth range from 400nm to 470nm, that is, the depth from this depth range is the thickness of the transition region. In other examples, Figure 3 From the hardness curve along the depth direction of a sampling point on the epitaxial wafer shown in (B), it can be seen that in the depth range from 0 to about 400nm, the hardness oscillates slightly with 10.5GPa as the benchmark, and in the depth range from about 470nm to 600nm, the hardness oscillates slightly with 10GPa as the benchmark, and in the depth range from about 400nm to about 470nm, the hardness changes, decreasing approximately linearly from 10.5GPa to 10GPa.

[0036] In some examples, 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 can be obtained based on the Young's modulus or hardness along the depth direction at each sampling point. By summarizing the thickness of the transition region at all sampling points according to the distribution of all sampling points on the front surface of the epitaxial wafer, a surface graph can be obtained, which represents the thickness of the transition region of the entire epitaxial wafer. Figure 3 By comparing (A) with (B), it can be found that in the depth range from about 400nm to about 470nm, the decrease in Young's modulus is significantly greater than the decrease in hardness. It can be seen more intuitively from the curve that compared with hardness, Young's modulus is more suitable for thickness detection.

[0037] Through the above technical scheme, the present invention utilizes the difference in mechanical properties to characterize the difference in physical properties of materials, and determines the thickness of the transition zone of the epitaxial wafer according to the change curve of material mechanical performance parameters such as Young's modulus or hardness along the depth direction. There is no need to perform too much pre-operation on the epitaxial wafer before detection, which reduces processing complexity and saves testing resources.

[0038] Based on the above technical solution, see Figure 4 , which shows another method for detecting the thickness of the transition region of an epitaxial wafer provided by the present disclosure, the method comprising: steps S401 to S406.

[0039] In step S401 , an epitaxial wafer is provided.

[0040] In the present disclosure, Figure 2 Similar to the scheme shown, the epitaxial wafer can be exemplarily Figure 1 As shown, the substrate is a heavily doped substrate and the epitaxial layer is a lightly doped epitaxial layer.

[0041] In step S402 , a plurality of first measurement points are evenly set at the center of the epitaxial wafer and at the edge of the epitaxial wafer.

[0042] In this disclosure, Figure 5 Taking the front surface of the epitaxial wafer as an example, Figure 5 In the figure, the center of the front surface of the epitaxial wafer is set to O, the edge of the epitaxial wafer is shown as a solid circle, and the first measurement points are set at the edge of the epitaxial wafer according to the set interval angle. In the present disclosure, the number of the first measurement points is 4, which are respectively identified as R1, R2, R3 and R4.

[0043] In step S403 , a plurality of second measurement points are evenly arranged on the auxiliary circle on the surface of the epitaxial wafer.

[0044] In this disclosure, continue to refer to Figure 5 , the auxiliary circle is shown as a dotted circle, with the center O of the epitaxial wafer as the center and half of the radius of the epitaxial wafer as the radius. On the auxiliary circle, the second measuring points are also set at the same interval angle as the first measuring points. In the present disclosure, the number of second measuring points is also 4, respectively identified as R1-1, R2-1, R3-1 and R4-1. Exemplarily, each first measuring point has a second measuring point correspondingly located on the same radius straight line. In the present disclosure, R1 and R1-1 are on the same radius straight line, R2 and R2-1 are on the same radius straight line, R3 and R3-1 are on the same radius straight line, and R4 and R4-1 are on the same radius straight line.

[0045] In step S404, the center of the epitaxial wafer, the first measurement point, and the second measurement point are used as sampling points, and the Young's modulus along the depth direction at each sampling point is measured respectively by a continuous stiffness method based on nanoindentation.

[0046] In the present disclosure, Young's modulus is used as an example of a material mechanical property parameter, and further reference is made to Figure 5 As shown in FIG. 1 , the center O of the epitaxial wafer, the first measuring points R1, R2, R3 and R4, and the second measuring points R1-1, R2-1, R3-1 and R4-1 are taken as sampling points, and the continuous stiffness method of nanoindentation is applied to each of these sampling points, so as to obtain a Young's modulus curve along the depth direction at each sampling point, in which the Young's modulus changes with depth as an example. Figure 3 The curves are similar to those shown in (A).

[0047] In step S405 , 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 based on the Young's modulus along the depth direction at each sampling point.

[0048] In the present disclosure, the Young's modulus curve along the depth direction at each sampling point is Figure 3 The curve in (A) is similar, such as Figure 6 In some examples, from the Young's modulus curve along the depth direction at each sampling point, the Young's modulus section (Flat Zone) of the epitaxial layer and the Young's modulus section of the substrate can be analyzed according to the amplitude of the oscillation of the curve, and the thickness from the Young's modulus section of the epitaxial layer to the Young's modulus section of the substrate is determined as the thickness of the transition zone (Transition).

[0049] For the above example, specifically, determining the thickness between the Young's modulus section of the epitaxial layer and the Young's modulus section of the substrate as the thickness of the transition region includes: Obtaining a difference between a Young's modulus section of the epitaxial layer and a Young's modulus section of the substrate; In the Young's modulus curve along the depth direction at the sampling point, 5% of the difference is taken as the starting point of the transition area, and 95% of the difference is taken as the end point of the transition area. The thickness of the transition area is obtained according to the depth value of the starting point of the transition area and the depth value of the end point of the transition area.

[0050] Specifically, in the Young's modulus section of the epitaxial layer and the Young's modulus section of the substrate, the curves oscillate slightly with a reference Young's modulus value. After obtaining the reference Young's modulus values ​​corresponding to the Young's modulus section of the epitaxial layer and the Young's modulus section of the substrate respectively according to the small-amplitude oscillation curves of the Young's modulus section of the epitaxial layer and the Young's modulus section of the substrate, the difference between the reference Young's modulus values ​​of the two sections is obtained, and the difference represents the change of the Young's modulus in the transition region.

[0051] For the above changes, in the Young's modulus curve, the present disclosure uses 5% of the difference as the starting point of the transition area, and 95% of the difference as the end point of the transition area, and the difference in depth between the starting point and the end point is the thickness of the transition area.

[0052] In step S406 , 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.

[0053] In the present disclosure, in combination with the aforementioned Figure 5 After obtaining the thickness value of the transition region at each sampling point according to the above step S405, the thickness value of the transition region at the 9 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 of the thickness values ​​of the transition region at the 9 sampling points can be used as the thickness value of the transition region of the entire epitaxial wafer.

[0054] It is understandable that those skilled in the art can also use hardness as a material mechanical property parameter to implement Figure 4 The technical solution shown will not be described in detail in this disclosure.

[0055] In addition, the deviation of the transition region at different radii on the surface of the epitaxial wafer can be obtained according to the thickness values ​​of the transition region at the nine sampling points.

[0056] Specifically, in the epitaxial wafer Deviation in the transition area at radius As shown in the following formula 1: (1) in, represents the thickness of the transition region at R1-1, represents the thickness of the transition region at R2-1, represents the thickness of the transition region at R3-1, represents the thickness of the transition region at R4-1, represents the thickness of the transition region at the center O of the epitaxial wafer.

[0057] At the radius of the epitaxial wafer, the deviation of the transition region As shown in Formula 2 below: (2) in, represents the thickness of the transition region at R1, represents the thickness of the transition region at R2, represents the thickness of the transition region at R3, represents the thickness of the transition region at R4, represents the thickness of the transition region at the center O of the epitaxial wafer.

[0058] For example, according to the aforementioned technical solution, the thickness of the epitaxial layer (Flat Zone) and the thickness of the transition zone (Transition) at the above 9 sampling points are shown in the second and third columns of Table 1. And for the above 9 sampling points, the thickness of the epitaxial layer and the transition zone are measured using the Spreading Resistance Profile (SRP) for comparison, which can be seen in the fourth and fifth columns of Table 1. In Table 1, the unit of thickness is nm.

[0059]

[0060] Table 1 According to the data shown in Table 1, the above formula 1 and formula 2 can be used to obtain the Deviation in the transition area at radius The deviation of the transition region is 7.61% at the radius of the epitaxial wafer. In addition, compared with the thickness of the epitaxial layer (Flat Zone by SPR) and the thickness of the transition zone (Transition by SPR) measured by the SRP method, the thickness values ​​measured by the technical solution of the present disclosure are closer to them. It can be seen that the present disclosure adopts the concept of measuring the thickness of the transition zone based on the difference in mechanical properties, and can also accurately measure the thickness of the epitaxial layer and the transition zone. Compared with the solution of measuring electrical parameters, it avoids pre-splitting, bonding, polishing and etching of the epitaxial wafer, reduces the processing complexity and saves test resources.

[0061] Based on the same inventive concept as the above technical solution, see Figure 7, which shows a device 70 for detecting the thickness of the transition region of an epitaxial wafer provided by the present disclosure, comprising: a measuring part 71 and a determining part 72; wherein, The measuring unit 71 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 substrate and the epitaxial layer of the epitaxial wafer have different doping concentrations; The determination 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.

[0062] For some examples, see Figure 8 The device 70 further includes a setting unit 73 configured to evenly set a plurality of first measurement points at the edge of the epitaxial wafer with the center of the epitaxial wafer; and evenly set a plurality of second measurement points on an auxiliary circle on the surface of the epitaxial wafer; wherein the auxiliary circle has the center as the center and has a radius of half the radius of the epitaxial wafer; Accordingly, the measuring unit 71 is configured as follows: The center of the epitaxial wafer, the first measurement point and the second measurement point are taken as sampling points, and the Young's modulus or hardness along the depth direction at each sampling point is measured respectively by a continuous stiffness method based on nanoindentation.

[0063] In some examples, the setting part 73 is configured to uniformly select a plurality of sampling points on the front surface of the epitaxial wafer; Accordingly, the measuring unit 71 is configured to measure the Young's modulus or hardness along the depth direction at each sampling point based on a continuous stiffness method of nanoindentation.

[0064] In some examples, the test parameters of the continuous stiffness method of nanoindentation are: The loading speed was 50 nN / s, the vibration frequency of the continuous stiffness measurement 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 s.

[0065] In some examples, the determining unit 72′ is configured to: 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 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 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.

[0066] In some examples, the determining unit 72′ is configured to: For each sampling point, from the Young's modulus curve along the depth direction at the sampling point, 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; Alternatively, for each sampling point, from the hardness curve along the depth direction at the sampling point, 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.

[0067] In some examples, the determining unit 72′ is configured to: Obtaining a difference between a Young's modulus section of the epitaxial layer and a Young's modulus section of the substrate; In the Young's modulus curve along the depth direction at the sampling point, 5% of the difference is taken as the starting point of the transition area, and 95% of the difference is taken as the end point of the transition area. The thickness of the transition area is obtained according to the depth value of the starting point of the transition area and the depth value of the end point of the transition area.

[0068] In some examples, the determining unit 72′ is configured to: Obtaining a difference between a hardness range of the epitaxial layer and a hardness range of the substrate; In the hardness curve along the depth direction at the sampling point, 5% of the difference is taken as the starting point of the transition area, and 95% of the difference is taken as the end point of the transition area. The thickness of the transition area is obtained according to the depth value of the starting point of the transition area and the depth value of the end point of the transition area.

[0069] Please refer to Fig. 9 , which shows a structural block diagram of a computing device provided by an exemplary embodiment of the present disclosure. In some examples, the computing device 90 may be at least one of a smart phone, a smart watch, a desktop computer, a laptop, a virtual reality terminal, an augmented reality terminal, a wireless terminal, and a laptop portable computer. The computing device 90 has a communication function and can access a wired network or a wireless network. The computing device 90 may generally refer to one of a plurality of terminals, and those skilled in the art may know that the number of the above terminals may be more or less. In some examples, the computing device 90 may receive data based on the wired network or wireless network to which it is connected. It can be 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 this.

[0070] like Fig. 9 As shown, the computing device in the present disclosure may include one or more of the following components: a processor 910 and a memory 920 .

[0071] Optionally, the processor 910 uses various interfaces and lines to connect various parts of the entire computing device, and executes various functions of the computing device and processes data by running or executing instructions, programs, code sets or instruction sets stored in the memory 920, and calling data stored in the memory 920. Optionally, the processor 910 can be implemented in at least one hardware form of digital signal processing (DSP), field-programmable gate array (FPGA), and programmable logic array (PLA). The processor 910 can integrate one or a combination of a central processing unit (CPU), a graphics processing unit (GPU), a neural network processor (NPU), and a baseband chip. Among them, the CPU mainly processes the operating system, user interface, and application programs; the GPU is responsible for rendering and drawing the content that needs to be displayed on the touch display; the NPU is used to implement artificial intelligence (AI) functions; and the baseband chip is used to process wireless communications. It is understandable that the above baseband chip may not be integrated into the processor 910, but may be implemented by a separate chip.

[0072] The memory 920 may include a random access memory (RAM) or a read-only memory (ROM). Optionally, the memory 920 includes a non-transitory computer-readable storage medium. The memory 920 may be used to store instructions, programs, codes, 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 a touch function, a sound playback function, an image playback function, etc.), instructions for implementing the above various method embodiments, etc.; the data storage area may store data created according to the use of the computing device, etc.

[0073] In addition, those skilled in the art can understand that the structure of the computing device shown in the above drawings does not constitute a limitation on the computing device, and the computing device may include more or fewer components than shown in the figure, or combine certain components, or arrange the components differently. For example, the computing device also includes a display screen, a camera assembly, a microphone, a speaker, a radio frequency circuit, an input unit, a sensor (such as an acceleration sensor, an angular velocity sensor, a light sensor, etc.), an audio circuit, a WiFi module, a power supply, a Bluetooth module and other components, which will not be described in detail here.

[0074] The present disclosure also provides a computer-readable storage medium storing at least one instruction, wherein the at least one instruction is used to be executed by a processor to implement the method for detecting the thickness of a transition region of an epitaxial wafer as described in the above embodiments.

[0075] The present disclosure also provides a computer program product, which includes 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 the processor executes the computer instructions, so that the computing device executes to implement the method of detecting the thickness of the transition region of the epitaxial wafer described in the above-mentioned embodiments.

[0076] Those skilled in the art should be aware that in one or more of the above examples, the functions described in the present disclosure can be implemented using hardware, software, firmware, or any combination thereof. When implemented using software, these functions can be stored in a computer-readable medium or transmitted as one or more instructions or codes on a computer-readable medium. Computer-readable media include computer storage media and communication media, wherein communication media include any media that facilitates the transmission of computer programs from one place to another. Storage media can be any available media that can be accessed by a general or special-purpose computer.

[0077] It should be noted that the technical solutions described in the present disclosure can be combined arbitrarily without conflict.

[0078] The above is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art can easily think of changes or substitutions within the technical scope disclosed by the present invention, which should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention should be based on the protection scope of the claims.

Claims

1. A method for detecting the thickness of a transition region of an epitaxial wafer, characterized in that: The method comprises: Providing an epitaxial wafer, wherein the substrate and the epitaxial layer of the epitaxial wafer have different doping concentrations; For sampling points on the front surface of the epitaxial wafer, measuring material mechanical property parameters along the depth direction at the sampling points; The thickness of a 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.

2. The method according to claim 1, characterized in that The method further comprises: Taking the center of the epitaxial wafer as an example, a plurality of first measurement points are evenly arranged on the edge of the epitaxial wafer; A plurality of second measurement points are evenly arranged on an auxiliary circle on the surface of the epitaxial wafer; wherein the auxiliary circle has the center as its center and has a radius that is half of the radius of the epitaxial wafer; Accordingly, the measuring of the material mechanical property parameters along the depth direction at the sampling point includes: The center of the epitaxial wafer, the first measurement point and the second measurement point are taken as sampling points, and the Young's modulus or hardness along the depth direction at each sampling point is measured respectively by a continuous stiffness method based on nanoindentation.

3. The method according to claim 1, characterized in that The method comprises: uniformly selecting a plurality of sampling points on the front surface of the epitaxial wafer; correspondingly, measuring the Young's modulus along the depth direction at the sampling points, including: The continuous stiffness method based on nanoindentation measures the Young's modulus or hardness along the depth direction at each of the sampling points.

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 was 50 nN / s, the vibration frequency of the continuous stiffness measurement 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 s.

5. The method according to claim 1, characterized in that The step of determining the thickness of a 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 comprises: 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 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 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.

6. The method according to claim 5, characterized in that The step of 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 based on the material mechanical property parameters along the depth direction at each sampling point comprises: For each sampling point, from the Young's modulus curve along the depth direction at the sampling point, 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; Alternatively, for each sampling point, from the hardness curve along the depth direction at the sampling point, 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.

7. The method according to claim 6, characterized in that The step of determining the thickness between the Young's modulus section of the epitaxial layer and the Young's modulus section of the substrate as the thickness of the transition region comprises: Obtaining a difference between a Young's modulus section of the epitaxial layer and a Young's modulus section of the substrate; In the Young's modulus curve along the depth direction at the sampling point, 5% of the difference is taken as the starting point of the transition area, and 95% of the difference is taken as the end point of the transition area. The thickness of the transition area is obtained according to the depth value of the starting point of the transition area and the depth value of the end point of the transition area.

8. The method according to claim 6, characterized in that The step of determining the thickness between the hardness section of the epitaxial layer and the hardness section of the substrate as the thickness of the transition region comprises: Obtaining a difference between a hardness range of the epitaxial layer and a hardness range of the substrate; In the hardness curve along the depth direction at the sampling point, 5% of the difference is taken as the starting point of the transition area, and 95% of the difference is taken as the end point of the transition area. The thickness of the transition area is obtained according to the depth value of the starting point of the transition area and the depth value of the end point of the transition area.

9. A device for detecting the thickness of a 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 substrate and the epitaxial layer of the epitaxial wafer have different doping concentrations; The determination unit is configured to determine a thickness of a transition region between the epitaxial layer of the epitaxial wafer and the substrate based on a material mechanical property parameter along a depth direction at the sampling point.

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

11. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores at least one instruction, and the at least one instruction is used to be executed by a processor to implement the method for detecting the thickness of a transition region of an epitaxial wafer as claimed in any one of claims 1 to 8.

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