Semiconductor substrate optical inspection system and method

Abstract

This invention discloses an optical inspection system and method for semiconductor substrates. The sample is placed at the inspection position, and an excitation light source is introduced into the sample for measurement. The excitation signal generated when the light source enters the sample in the forward direction is called the forward excitation signal, and the excitation signal generated when the light source enters the sample and is reflected by another interface of the sample is called the reverse excitation signal. The system collects the forward and reverse excitation signals, and then generates high-resolution images of the shape and defects of the micropore walls through signal processing and image generation modules, thereby realizing accurate detection of the internal structure of the micropores.

Description

Technical Field

[0001] This invention relates to an optical inspection system and method for semiconductor substrates. Background Technology

[0002] In traditional optical experiments or imaging, excitation light is typically focused through an optical lens onto the front (light-facing) side of the sample and penetrates slightly into the sample's interior, thereby generating corresponding optical reactions (such as scattering or reflection) on the sample surface or shallow interior. The main limitation of this excitation method is that the excitation light is always directed towards the front of the sample, failing to illuminate the back side or internal structure. However, the internal structure of some samples cannot be revealed by frontal excitation light. Furthermore, since the excitation light can only illuminate the front of the sample, the structure or optical properties of the back side cannot be effectively excited or measured. This significantly limits the range of measurement and detection when data needs to be obtained from different angles or depths. Therefore, traditional excitation light illumination methods cannot provide comprehensive data, especially in deep structural analysis or specific situations (such as high aspect ratio micropores). Summary of the Invention

[0003] Based on the above problems, the purpose of this invention is to provide an optical inspection system and method for semiconductor substrates, which is mainly used for the inspection of micro-holes with high aspect ratio. It has good inspection effect and can also be extended to the inspection of the inside or back side of wafers or semiconductor substrates in practical applications.

[0004] To achieve the above objectives, the present invention adopts the following technical solution: An optical inspection system for semiconductor substrates, characterized in that it comprises: One sample, located at one detection position; A light source module provides an excitation light; the excitation light is incident from the front of the sample into the interior of a micropore with a high aspect ratio, thereby generating a positive excitation signal; An interface is provided to reflect the excitation light incident on the micropore into a reverse excitation light, which returns from the back of the sample to the inside of the micropore, thereby generating a reverse excitation signal. A photodetector receives the forward excitation signal and the reverse excitation signal, and converts the signals into electrical signals; A signal processing and image generation module, coupled to the photodetector, is used to acquire and process the electrical signal and generate a geometric structure image of the micropore; the geometric structure image presents the forward and reverse two-dimensional shapes of the micropore wall and its defects in a high-resolution manner.

[0005] An optical inspection system for semiconductor substrates, characterized in that it comprises: One sample, located at one detection position; A light source module provides an excitation light; the excitation light is incident from the front of the sample into the interior of a micropore with a high aspect ratio, thereby generating a positive excitation signal; An interface is used to reflect the excitation light incident on the micropore into a reverse excitation light and return it to the interior of the micropore, thereby generating a reverse excitation signal. A photodetector is used to receive the forward excitation signal and the reverse excitation signal, and convert the signals into electrical signals; A vertical axis propulsion module controls one or a combination of the light source module, the photodetector and related optical objects, and the sample to propel along a vertical axis, generating the positive excitation signal and the reverse excitation signal of the micropore layer by layer along the propulsion direction; A signal processing and image generation module, coupled to the photodetector module, is used to acquire and process the electrical signal and generate a geometric structure image of the micropore; the geometric structure image presents the three-dimensional shape of the micropore wall and its defects in a high-resolution manner.

[0006] The interface is a reflective layer located within the sample structure.

[0007] The interface is a reflective layer disposed on the surface of a stage, which supports the back side of the sample.

[0008] The interface includes a light-reflecting structural layer fixed to the back of the sample or inside the sample.

[0009] The photodetector is selected from one or a combination of a photodiode (PD), an avalanche photodiode (APD), a charge-coupled device (CCD), a photomultiplier tube (PMT).

[0010] The wavelength of the excitation light is 1200–1800 nm.

[0011] The excitation light is from an ultrafast laser.

[0012] The light source module and the photodetector are a coaxial system.

[0013] An optical inspection method for semiconductor substrates, comprising: An excitation light is provided and incident from the front of a sample into the interior of a micropore with a high aspect ratio, thereby generating a positive excitation signal; An interface is provided to reflect the excitation light incident on the micropore into a reverse excitation light and return it to the interior of the micropore, thereby generating a reverse excitation signal. Receive the positive excitation signal and the negative excitation signal, and convert the signal into an electrical signal; and Based on the electrical signal, a two-dimensional image of the micropore wall shape and its defects is generated.

[0014] A method for optical inspection of a semiconductor substrate, characterized in that it includes: An excitation light is provided and incident from the front of a sample into the interior of a micropore with a high aspect ratio, thereby generating a positive excitation signal; An interface is provided to reflect the excitation light incident on the micropore into a reverse excitation light and return it to the interior of the micropore, thereby generating a reverse excitation signal. The excitation light and its associated optical objects, the sample, or a combination thereof are controlled to advance along a vertical axis, thereby generating the forward excitation signal and the reverse excitation signal of the micropore layer by layer; Receive the positive excitation signal and the negative excitation signal, and convert these signals into electrical signals; and Based on the electrical signal, an image of the three-dimensional pore wall shape and its defects is generated.

[0015] A method for optical inspection of a semiconductor substrate, characterized in that it includes: An excitation light is provided and incident from the front of a sample onto a designated area of ​​the sample, thereby generating a positive excitation signal in the designated area; An interface is provided to reflect the excitation light into a reverse excitation light and return it to the designated area, thereby generating a reverse excitation signal in the designated area; Receive the positive excitation signal and the negative excitation signal, and convert the signal into an electrical signal; and An image of the specified area is generated based on the electrical signal.

[0016] A method for optical inspection of a semiconductor substrate, characterized in that it includes: An excitation light is provided and incident from the front of a sample onto a designated area of ​​the sample, thereby generating a positive excitation signal in the designated area; An interface is provided to reflect the excitation light into a reverse excitation light and return it to the designated area, thereby generating a reverse excitation signal in the designated area; The excitation light and its associated optical objects, the sample, or a combination thereof are controlled to advance along a vertical axis, thereby generating the positive excitation signal and the reverse excitation signal of the designated region layer by layer; Receive the positive excitation signal and the negative excitation signal, and convert these signals into electrical signals; and A three-dimensional image of the specified area is generated based on the electrical signal.

[0017] The excitation light and the reverse excitation light are coaxial.

[0018] An optical inspection system and method for semiconductor substrates involves placing a sample at the inspection position, introducing an excitation light source into the sample for measurement, and generating an excitation signal when the light source enters the sample in the forward direction (called a forward excitation signal) and an excitation signal when the light source enters the sample and is reflected by another interface of the sample (called a reverse excitation signal). The system collects the forward and reverse excitation signals and then generates high-resolution images of the shape and defects of the micropore walls through signal processing and image generation modules, thereby achieving accurate detection of the internal structure of the micropores.

[0019] An optical inspection system and method for semiconductor substrates involves placing a sample at a detection position. Excitation light provided by a light source module is incident from the front of the sample onto a designated area to generate a forward excitation signal. Simultaneously, an interface on the back of the sample reflects the excitation light as a reverse excitation light, which then re-enters the designated area of ​​the sample from the back to generate a reverse excitation signal. The system collects the forward and reverse excitation signals and then uses a signal processing and image generation module to generate a high-resolution image of the shape and defects of the designated area of ​​the sample, thereby achieving accurate detection of the internal structure of the designated area.

[0020] The beneficial effects of this invention are: In reverse excitation, a portion of the excitation light penetrates the sample and then returns from the back of the sample to re-enter the sample.

[0021] The system records both forward and reverse excitation signals, achieving bidirectional signal acquisition. This provides information on both the forward and reverse directions of the sample, offering a more complete picture of its characteristics. By analyzing the bidirectional signals, the physical properties of the sample, such as thickness, depth, or other relevant information, can be deduced.

[0022] It accurately presents the micropore structure, clearly showing the shape, size, and defects of the micropore walls, providing highly accurate detection results.

[0023] By combining signals excited by forward and reverse light, we can gain a more comprehensive understanding of the internal structure of micropores.

[0024] Optical inspection does not cause physical damage to the sample and is suitable for situations where sample integrity is a high priority.

[0025] The same sample can be tested multiple times, which facilitates comparative analysis.

[0026] It can accurately locate and identify various defects in micropores, such as pore wall roughness and pore diameter inhomogeneity. Attached Figure Description

[0027] Figure 1 Schematic diagram of the state of the sample of the present invention Figure 1 .

[0028] Figure 2 Schematic diagram of the state of the sample of the present invention Figure 2 .

[0029] Figure 3 Block diagram of the first embodiment of the detection system of the present invention.

[0030] Figure 4 A schematic diagram of the first embodiment of the detection method of the present invention.

[0031] Figure 5 Block diagram of the second embodiment of the detection system of the present invention.

[0032] Figure 6 A schematic diagram of the second embodiment of the detection method of the present invention.

[0033] Figure 7 A schematic diagram of the third embodiment of the detection method of the present invention.

[0034] Figure 8 A schematic diagram of the fourth embodiment of the detection method of the present invention.

[0035] Figure 9 Two-dimensional image of micropores of the present invention.

[0036] Figure 10 The present invention provides a two-dimensional image of micropores.

[0037] Figure 11 Three-dimensional images of micropores in this invention.

[0038] 10: Sample 11: Front 12: Back 13: Micropores 21: Non-metallic layer 22: Non-metallic layer 23: Electrode layer / metal layer 24: Silicon base layer 25: Reflective layer 30: Light source module 31: Interface 32: Vertical axis propulsion module 33: Light Detector 34: Signal Processing and Image Generation Module 35: Excitation Light 36: Reverse excitation light 41: Geometric structure image 42: Geometric structure image 43: Cross-sectional shape of micropores 44: Highlights 45: High Gloss Micro-Curve 50: Platform 60: Specified area Detailed Implementation

[0039] The embodiments of the present invention will be described below with reference to the accompanying drawings and examples. The illustrations provided in the following examples are only schematic representations of the basic concept of the present invention. Therefore, the drawings only show components related to the present invention and are not drawn according to the actual number, shape and size of the elements in the implementation.

[0040] like Figure 1 Regarding the first state of sample 10 of the present invention, sample 10 is a semiconductor 3D packaging structure. Sample 10 includes micropores 13 with high aspect ratio features, including but not limited to through-silicon vias (TSVs) and through-glass vias (TGVs). Component symbols 21 and 22 represent non-metallic layers, typically insulating layers, photoresist layers, or other functional layers, and can be single-layer or multi-layer structures. Component symbol 23 represents an electrode layer, typically a metal layer 23. Component symbol 24 represents a silicon substrate. In this invention, the electrode layer / metal layer 23 of sample 10 can be used as an interface 31. In addition, the interface between different media can also be used as an interface 31 to reverse the excitation light, or the interface includes a light-reflecting structural layer fixed to the back side or inside the sample.

[0041] like Figure 2 Regarding the second embodiment of sample 10 of the present invention, sample 10 is a semiconductor 3D package structure. Sample 10 includes micro-holes 13 with high aspect ratio features, including but not limited to through-silicon vias (TSVs) and through-glass vias (TGVs). Component symbols 21 and 22 represent non-metallic layers, typically insulating layers, photoresist layers, or other functional layers, and can be single-layer or multi-layer structures. A reflective layer 25 is further provided on the back surface 12 of sample 10, which can be selected from a highly reflective mirror, a reflective material, or a thin film with special optical properties. The reflective layer 25 is mounted on the surface of a stage 50 used to support sample 10, and the reflective layer 25 is in contact with the back surface 12 of sample 10. The reflective layer 25 is used as an interface 31 in the present invention.

[0042] like Figure 3 Regarding the detection system, the first embodiment of the present invention includes: Sample 10, light source module 30, interface 31, photodetector 33, and signal processing and image generation module 34.

[0043] Sample 10, as described above and Figure 1 and Figure 2 The person mentioned.

[0044] The light source module 30 provides an excitation light 35 with a wavelength of 1200–1800 nm. This excitation light is an ultrafast laser. The excitation light 35 is focused and incident from the front side 11 of the sample 10 into the interior of the micropore 13, generating a forward excitation signal. This focusing technique can employ one or more sets of optical elements, including but not limited to lenses and mirrors, to precisely adjust the focusing position of the excitation light 35, ensuring that the excitation light 35 accurately incident into the interior of the micropore 13.

[0045] The interface 31, such as the metal layer or reflective layer 25 of the aforementioned sample 10, is disposed on the back surface 12 of the sample 10 to reflect the excitation light 35 incident on the micropore 13 into a reverse excitation light 36, which returns from the back surface 12 of the sample 10 to the interior of the micropore 13, generating a reverse excitation signal. Furthermore, the interface 31 can be designed with an adjustable angle and variable reflectivity to adjust the reflection efficiency.

[0046] The photodetector 33 receives the forward excitation signal and the reverse excitation signal, and converts these signals into electrical signals. The photodetector 33 is selected from one or a combination of a photodiode (PD), an avalanche photodiode (APD), a charge-coupled device (CCD), and a photomultiplier tube (PMT). In the illustration of this invention, the light source module 30 and the photodetector 33 are a coaxial system.

[0047] The signal processing and image generation module 34, coupled to the photodetector 33, is used to acquire and process the electrical signal and generate a geometric structure image 41 of the micropore 13; the geometric structure image 41 presents the two-dimensional shape of the micropore wall and its defects in a high-resolution manner, such as... Figure 9 and Figure 10 The image displays the cross-sectional shape 43 of the micropore 13, with the highlight 44 representing defects such as uneven pore wall. The signal processing and image generation module 34 may include a digital signal processor, a high-performance calculator, or dedicated firmware to process electrical signals from the photodetector 33 in real time and generate high-resolution geometric images using algorithms. It can also further identify and quantitatively analyze defects. The generated micropore images can display the pore wall shape, identify pore wall defects (such as cracks, weak points, and material inhomogeneities), and provide precise geometric information, including pore diameter, depth, and shape.

[0048] like Figure 4 Based on the first embodiment described above, the present invention provides a detection method, comprising: An excitation light 35 is provided and focused from the front side 11 of a sample 10 into the interior of a micropore 13 with a high aspect ratio, thereby generating a positive excitation signal. An interface 31 is provided on the back surface 12 of the sample 10 to reflect the excitation light 35 incident on the micropore 13 into a reverse excitation light 36, which returns from the back surface 12 of the sample 10 to the inside of the micropore 13, thereby generating a reverse excitation signal. Receive the positive excitation signal and the negative excitation signal, and convert the signal into an electrical signal; and Based on the electrical signal, a two-dimensional image of the shape of the micropore wall and its defects is generated.

[0049] like Figure 5 Regarding the detection system, the second embodiment of the present invention includes: Sample 10, light source module 30, interface 31, vertical axis propulsion module 32, photodetector 33, and signal processing and image generation module 34.

[0050] Sample 10, as described above and Figure 1 and Figure 2 The person mentioned.

[0051] The light source module 30 provides an excitation light 35 with a wavelength of 1200–1800 nm. This excitation light is an ultrafast laser. The excitation light 35 is focused and incident from the front side 11 of the sample 10 into the interior of the micropore 13, generating a forward excitation signal. This focusing technique can employ one or more sets of optical elements, including but not limited to lenses and mirrors, to precisely adjust the focusing position of the excitation light 35, ensuring that the excitation light 35 accurately incident into the interior of the micropore 13.

[0052] The interface 31, such as the metal layer 23 or reflective layer 25 of the aforementioned sample 10, is disposed on the back surface 12 of the sample 10 to reflect the excitation light 35 incident on the micropore 13 into a reverse excitation light 36, which returns from the back surface 12 of the sample 10 to the interior of the micropore 13, generating a reverse excitation signal. Furthermore, the interface 31 can be designed with an adjustable angle and variable reflectivity to adjust the reflection efficiency.

[0053] The vertical axis propulsion module 32 controls the light source module 30, the photodetector 33, and its associated optical components (such as...). Figure 5 The sample 10 (enclosed by the dashed line) is selected and advanced along the vertical axis, generating the forward excitation signal and the reverse excitation signal of the micropore 13 layer by layer along the advancement direction. The vertical axis advancement module 32 may include a moving mechanism, a guiding system, and a precision position control device to achieve the above-mentioned precise vertical movement, perform layer-by-layer scanning, and generate multiple layers of forward and reverse light signals to obtain the complete micropore 13 structure signal.

[0054] The photodetector 33 receives the forward excitation signal and the reverse excitation signal, and converts these signals into electrical signals. The photodetector 33 is selected from one or a combination of a photodiode (PD), an avalanche photodiode (APD), a charge-coupled device (CCD), and a photomultiplier tube (PMT). In the illustration of this invention, the light source module 30 and the photodetector 33 are a coaxial system.

[0055] The signal processing and image generation module 34, coupled to the photodetector module, is used to acquire and process the electrical signal and generate a geometric structure image 42 of the micropore 13; the geometric structure image 42 presents the three-dimensional hole wall shape and defects of the micropore 13 in high-resolution features. Figure 11 In the image, the bright line micro-curve 45 represents the longitudinal shape of the pore wall. The signal processing and image generation module 34 may include a digital signal processor, a high-performance calculator, or dedicated firmware to process electrical signals from the photodetector 33 in real time and generate high-resolution geometric images using algorithms. It can also further perform defect identification and quantitative analysis. The generated micropore images can display the shape of the micropore walls, identify pore wall defects (such as cracks, weak points, material inhomogeneities, etc.), and provide accurate geometric information, including features such as pore diameter, depth, and shape.

[0056] like Figure 6 Based on the second embodiment described above, the present invention provides a detection method, comprising: An excitation light 35 is provided and focused from the front side 11 of a sample 10 and incident into the interior of a micropore 13 with a high aspect ratio, thereby generating a positive excitation signal. An interface 31 is provided on the back surface 12 of the sample 10 to reflect the excitation light 35 incident on the micropore 13 into a reverse excitation light 36, which returns from the back surface 12 of the sample 10 to the inside of the micropore 13, thereby generating a reverse excitation signal. The excitation light 35 and its associated optical objects, the sample 10, or a combination thereof, are controlled to advance along a vertical axis, thereby generating the forward excitation signal and the reverse excitation signal of the micropore 13 layer by layer. Receive the positive excitation signal and the negative excitation signal, and convert these signals into electrical signals; and Based on the electrical signal, an image of the three-dimensional hole wall shape and its defects of the micropore 13 is generated.

[0057] like Figure 7In a third embodiment of the present invention, the sample 10 is an optically transparent material, including but not limited to silicon. In this embodiment, the sample 10 is supported by a stage 50, and the stage 50 is provided with an interface 31 that contacts the sample 10.

[0058] According to a third embodiment, the present invention provides a detection method for detecting internal defects in a semiconductor substrate. The method includes: An excitation light 35 is provided and focused from the front side 11 of the sample 10 onto a designated area 60 of the sample 10, thereby generating a positive excitation signal for the designated area 60; the interface 31 reflects the excitation light 35 that has penetrated the sample 10 into a reverse excitation light 36, which returns from the back side 12 of the sample 10 to the designated area 60 of the sample 10, thereby generating a reverse excitation signal for the designated area 60; the interface 31 receives the positive excitation signal and the reverse excitation signal and converts the signal into an electrical signal; and generates a two-dimensional image of the designated area 60 based on the electrical signal.

[0059] In the third embodiment, as shown in the figure, the excitation light 35 and the reverse excitation light 36 are coaxial.

[0060] like Figure 8 In a fourth embodiment of the present invention, the sample 10 is an optically transparent material, including but not limited to silicon. In this embodiment, the sample 10 is supported by a stage 50, and the stage 50 is provided with an interface 31 that contacts the sample 10.

[0061] According to a fourth embodiment, the present invention provides a detection method for detecting internal defects in semiconductor materials or packaging substrates. The method includes: An excitation light 35 is provided and focused onto a designated area 60 of a sample 10 from the front side 11, thereby generating a positive excitation signal in the designated area 60; the interface 31 reflects the excitation light 35 that has penetrated the sample 10 into a reverse excitation light 36, which returns from the back side 12 of the sample 10 to the designated area 60, thereby generating a reverse excitation signal in the designated area 60; the excitation light 35 and its associated optical objects, the sample 10, or a combination thereof, are controlled to advance along a vertical axis, thereby generating the positive and reverse excitation signals of the designated area 60 layer by layer; the positive and reverse excitation signals are received and converted into electrical signals; and a three-dimensional image of the designated area 60 is generated based on the electrical signals.

[0062] In the fourth embodiment, as shown in the figure, the excitation light 35 and the reverse excitation light 36 are coaxial.

Claims

1. A semiconductor substrate optical inspection system, characterized in that: include: One sample, located at one detection position; A light source module provides an excitation light; The excitation light is incident from the front of the sample into the interior of a micropore with a high aspect ratio, thereby generating a positive excitation signal; An interface is provided to reflect the excitation light incident on the micropore into a reverse excitation light, which returns from the back of the sample to the inside of the micropore, thereby generating a reverse excitation signal. A photodetector receives the forward excitation signal and the reverse excitation signal, and converts the signals into electrical signals; A signal processing and image generation module, coupled to the photodetector, is used to acquire and process the electrical signal and generate a geometric image of the micropore. The geometric image presents the forward and reverse two-dimensional shapes of the micropore walls and their defects in a high-resolution manner.

2. The semiconductor substrate optical inspection system as described in claim 1, characterized in that: The interface is a reflective layer located within the sample structure.

3. The semiconductor substrate optical inspection system as described in claim 1, characterized in that: The interface is a reflective layer disposed on the surface of a stage, which supports the back side of the sample.

4. The semiconductor substrate optical inspection system as described in claim 1, characterized in that: The interface includes a light-reflecting structural layer fixed to the back of the sample or inside the sample.

5. The semiconductor substrate optical inspection system as described in claim 1, characterized in that: The photodetector is selected from one or a combination of a photodiode (PD), an avalanche photodiode (APD), a charge-coupled device (CCD), a photomultiplier tube (PMT).

6. The semiconductor substrate optical inspection system as described in claim 1, characterized in that: The wavelength of the excitation light is 1200–1800 nm.

7. The semiconductor substrate optical inspection system as described in claim 1, characterized in that: The excitation light is from an ultrafast laser.

8. The semiconductor substrate optical inspection system as described in claim 1, characterized in that: The light source module and the photodetector are a coaxial system.

9. A semiconductor substrate optical inspection system, characterized in that: include: One sample, located at one detection position; A light source module provides an excitation light; The excitation light is incident from the front of the sample into the interior of a micropore with a high aspect ratio, thereby generating a positive excitation signal; An interface is used to reflect the excitation light incident on the micropore into a reverse excitation light and return it to the interior of the micropore, thereby generating a reverse excitation signal. A photodetector is used to receive the forward excitation signal and the reverse excitation signal, and convert the signals into electrical signals; A vertical axis propulsion module controls one or a combination of the light source module, the photodetector and related optical objects, and the sample to propel along a vertical axis, generating the positive excitation signal and the reverse excitation signal of the micropore layer by layer along the propulsion direction; A signal processing and image generation module, coupled to the photodetector module, is used to acquire and process the electrical signal and generate a geometric structure image of the micropore; The geometric image presents the three-dimensional shape of the micropore wall and its defects in high-resolution features.

10. The semiconductor substrate optical inspection system as described in claim 9, characterized in that: The interface is a reflective layer located within the sample structure.

11. The semiconductor substrate optical inspection system as described in claim 9, characterized in that: The interface is a reflective layer disposed on the surface of a stage, which supports the back side of the sample.

12. The semiconductor substrate optical inspection system as described in claim 9, characterized in that: The interface includes a light-reflecting structural layer fixed to the back of the sample or inside the sample.

13. The semiconductor substrate optical inspection system as described in claim 9, characterized in that: The photodetector is selected from one or a combination of a photodiode (PD), an avalanche photodiode (APD), a charge-coupled device (CCD), a photomultiplier tube (PMT).

14. The semiconductor substrate optical inspection system as described in claim 9, characterized in that: The wavelength of the excitation light is 1200–1800 nm.

15. The optical inspection system for semiconductor substrates as described in claim 9, characterized in that: The excitation light is from an ultrafast laser.

16. The semiconductor substrate optical inspection system as described in claim 9, characterized in that: The light source module and the photodetector are a coaxial system.

17. A method for optical inspection of a semiconductor substrate, comprising: An excitation light is provided and incident from the front of a sample into the interior of a micropore with a high aspect ratio, thereby generating a positive excitation signal; An interface is provided to reflect the excitation light incident on the micropore into a reverse excitation light and return it to the interior of the micropore, thereby generating a reverse excitation signal. Receive the positive excitation signal and the negative excitation signal, and convert the signal into an electrical signal; and Based on the electrical signal, a two-dimensional image of the micropore wall shape and its defects is generated.

18. The optical inspection method for a semiconductor substrate as described in claim 17, characterized in that: The excitation light and the reverse excitation light are coaxial.

19. A method for optical inspection of a semiconductor substrate, characterized in that: include: An excitation light is provided and incident from the front of a sample into the interior of a micropore with a high aspect ratio, thereby generating a positive excitation signal; An interface is provided to reflect the excitation light incident on the micropore into a reverse excitation light and return it to the interior of the micropore, thereby generating a reverse excitation signal. The excitation light and its associated optical objects, the sample, or a combination thereof are controlled to advance along a vertical axis, thereby generating the forward excitation signal and the reverse excitation signal of the micropore layer by layer; Receive the positive excitation signal and the negative excitation signal, and convert these signals into electrical signals; and Based on the electrical signal, an image of the three-dimensional pore wall shape and its defects is generated.

20. The optical inspection method for semiconductor substrates as described in claim 19, characterized in that: The excitation light and the reverse excitation light are coaxial.

21. A method for optical inspection of a semiconductor substrate, characterized in that: include: An excitation light is provided and incident from the front of a sample onto a designated area of ​​the sample, thereby generating a positive excitation signal in the designated area; An interface is provided to reflect the excitation light into a reverse excitation light and return it to the designated area, thereby generating a reverse excitation signal in the designated area; Receive the positive excitation signal and the negative excitation signal, and convert the signal into an electrical signal; and An image of the specified area is generated based on the electrical signal.

22. The optical inspection method for semiconductor substrates as described in claim 21, characterized in that: The excitation light and the reverse excitation light are coaxial.

23. A method for optical inspection of a semiconductor substrate, characterized in that: include: An excitation light is provided and incident from the front of a sample onto a designated area of ​​the sample, thereby generating a positive excitation signal in the designated area; An interface is provided to reflect the excitation light into a reverse excitation light and return it to the designated area, thereby generating a reverse excitation signal in the designated area; The excitation light and its associated optical objects, the sample, or a combination thereof are controlled to advance along a vertical axis, thereby generating the positive excitation signal and the reverse excitation signal of the designated region layer by layer; Receive the positive excitation signal and the negative excitation signal, and convert these signals into electrical signals; and A three-dimensional image of the specified area is generated based on the electrical signal.

24. The optical inspection method for semiconductor substrates as described in claim 23, characterized in that: The excitation light and the reverse excitation light are coaxial.

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