A full-size high-precision semiconductor measurement and detection system

Abstract

The utility model discloses a full size high precision's pan semiconductor measurement detection system, it includes light source module, imaging light path, camera module and image processing calculation module, the light source module includes the light source generator of providing illumination light and the wavelength processor of illumination light processing into first light, the imaging light path includes first mirror group, light splitting device, first objective and first lens, the camera module gathers the reflected light of imaging light path transmission to its detection surface and forms the image to obtain the reflection light image of the sample under the illumination of third light, the image processing calculation module includes the image processing unit of carrying out the processing to the reflection light image and the measurement system of carrying out the calculation measurement and obtaining the film thickness distribution image, the utility model can obtain the film thickness distribution image of sample, can avoid the measurement error of film thickness measurement, and the film thickness of thickness uneven is convenient for analysis.

Description

Technical Field

[0001] This utility model belongs to the field of semiconductor processing technology, and in particular relates to a full-size, high-precision semiconductor measurement and testing system. Background Technology

[0002] In the field of semiconductor manufacturing processes, such as chip fabrication and display panel fabrication, the transformation from an initial substrate to a final chip or display panel requires numerous thin film deposition or coating processes, as well as surface etching processes. Measuring the film thickness in semiconductor manufacturing has always been crucial for verifying and controlling the manufacturing process and improving yield rates, especially given the increasing demand for increasingly intricate patterns. This has led to a need for accurate measurement of the film thickness for fine patterns or the entire sample surface.

[0003] While existing thin-film thickness measurement tools can accurately measure film thickness—for example, the measurement system, method, and storage medium disclosed in Chinese Patent Publication No. CN117781899A—use a spectrometer to measure the film thickness within a region, selecting several points within the measurement area and calculating the average value. This reflects the average film thickness over the spot area, making it difficult to reflect the film thickness distribution within that area. For films with uneven thickness, using the above-mentioned single-point measurement and averaging method will result in significant measurement errors, affecting subsequent semiconductor processes and yield. To solve these problems, a measurement and detection system capable of displaying the distribution of thin-film thickness is needed.

[0004] Therefore, it is necessary to provide a full-size, high-precision semiconductor measurement and inspection system to solve the above-mentioned technical problems. Utility Model Content

[0005] The main objective of this invention is to provide a full-size, high-precision semiconductor measurement and testing system that can obtain the film thickness distribution image of the sample under test, avoid measurement errors in film thickness measurement, and facilitate the analysis of film thicknesses with uneven thickness.

[0006] The present invention achieves the above objectives through the following technical solution: a full-size, high-precision semiconductor measurement and detection system, comprising a light source module, an imaging optical path, a camera module, and an image processing and computing module;

[0007] The light source module includes a light source generator that provides illumination light and a wavelength processor that processes the illumination light into a first light ray;

[0008] The imaging optical path includes a first mirror group, a beam splitter, a first objective lens, and a first lens. The first mirror group homogenizes the first light beam to obtain a second light beam. The beam splitter converts the second light beam into a third light beam. The third light beam is transmitted along a first direction to the first objective lens below and illuminates a first position in the test area of ​​the sample. At the same time, the first objective lens couples the reflected light beam obtained from the sample to the beam splitter along a second direction opposite to the first direction. The first lens, in conjunction with the first objective lens, transmits the reflected light beam from the beam splitter to the detection surface of the camera module.

[0009] The camera module acquires the reflected light transmitted to its detection surface by the imaging optical path and forms an image to obtain an image of the reflected light of the sample under the illumination of the third light.

[0010] The image processing and calculation module includes an image processing unit that processes the reflected light image and a measurement system that calculates and measures the film thickness distribution image.

[0011] Furthermore, a moving stage for carrying the sample to be tested is provided below the first objective lens, and the moving stage is capable of moving laterally and / or longitudinally.

[0012] Furthermore, the imaging optical path also includes a reflector and a second objective lens. The reflector receives a fourth ray transmitted along a third direction via a beam splitter and directs the fourth ray onto the second objective lens.

[0013] Furthermore, the imaging optical path also includes an objective lens switching stage disposed below the beam splitter, wherein both the first objective lens and the second objective lens are mounted on the objective lens switching stage.

[0014] Furthermore, a second mirror group is provided between the first mirror group and the beam splitter to change the aspect ratio of the light spot.

[0015] Furthermore, the second lens group includes adjacent curved lens groups for compressing the second light rays in the X and Y directions, respectively, and the curved lens group includes plano-concave cylindrical lenses and / or plano-convex cylindrical lenses.

[0016] Furthermore, the curved lens group includes a first plano-concave cylindrical lens, a first plano-convex cylindrical lens, a second plano-convex cylindrical lens, and a second plano-concave cylindrical lens.

[0017] Furthermore, the image processing calculation module also includes an image algorithm processing unit capable of identifying image features of the area to be tested.

[0018] Furthermore, the camera module is selected from one or more of an area scan camera, a line scan camera, and a TDI camera.

[0019] Furthermore, the wavelength processor is selected from one or more of a grating wavelength selector, a color wheel device, or a monochromator.

[0020] Compared with existing technologies, the advantages of this utility model's full-size, high-precision semiconductor measurement and testing system are as follows:

[0021] (1) An image processing and calculation module is provided. After the camera module collects the reflected light transmitted to its detection surface through the imaging optical path to obtain the reflected light image of the sample under different wavelengths of light illumination, the image processing unit and the measurement system of the image processing and calculation module process and calculate the reflected light image to obtain the film thickness distribution image of the test area of ​​the sample. Through image stitching and full film thickness measurement, a high-precision film thickness distribution map is generated to avoid measurement error in film thickness measurement and facilitate the analysis of thin films with uneven thickness. The image processing and calculation module also integrates an image algorithm processing unit, which can perform defect detection and linewidth measurement, improve the overall performance of the system, and enhance the versatility of the system.

[0022] (2) The imaging optical path includes a second mirror group that can shape the circular or square beam into a uniform strip beam. Using a strip beam can increase the coverage area of ​​a single scan, and the efficiency is significantly improved compared to a circular spot. The second mirror group can compress the circular spot in the X and Y directions, change the aspect ratio of the spot, and adapt to different measurement conditions. Attached Figure Description

[0023] Figure 1 This is a schematic diagram of the structure of a full-size, high-precision semiconductor measurement and detection system according to an embodiment of the present invention;

[0024] Figure 2 This is a schematic diagram of the structure of a full-size, high-precision semiconductor measurement and detection system according to an embodiment of the present invention;

[0025] Figure 3 This is a schematic diagram of the structure of the first and second lens groups in an embodiment of the present invention;

[0026] Figure 4 This is a schematic diagram of the circular light spot structure according to an embodiment of the present invention;

[0027] Figure 5 This is a schematic diagram of the structure of the strip-shaped light spot in an embodiment of the present invention;

[0028] The numbers in the image represent:

[0029] 100 - Full-size, high-precision semiconductor measurement and testing system; 200 - Samples to be tested;

[0030] 1-Light source module, 11-Light source generator, 12-Wavelength processor;

[0031] 2-Imaging optical path, 21-First lens group, 22-Beam splitter, 23-First objective lens, 24-First lens, 25-Reflector, 26-Second objective lens, 27-Objective lens switching stage, 28-Second lens group, 281-First plano-concave cylindrical lens, 282-First plano-convex cylindrical lens, 283-Second plano-convex cylindrical lens, 284-Second plano-concave cylindrical lens, 29-Third objective lens;

[0032] 3-Camera module;

[0033] 4-Image processing calculation module, 41-Image processing unit, 42-Measurement system, 43-Image algorithm processing unit;

[0034] 5-Mobile station. Detailed Implementation

[0035] Please refer to Figures 1-5 This embodiment is a full-size, high-precision semiconductor measurement and detection system 100, which includes a light source module 1, an imaging optical path 2, a camera module 3, and an image processing and calculation module 4, which are described in detail below.

[0036] The light source module 1 includes a light source generator 11 and a wavelength processor 12.

[0037] The light source generator 11 is used to provide illumination light with various center wavelengths. In this embodiment, the light source generator 11 provides a broadband light source, the specific spectral band of which is determined by the sample being tested. It can be selected from one or more of xenon lamps, LED lamps, laser-driven white light sources (LDLS), and halogen lamps. Xenon lamps, LED lamps, laser-driven white light sources (LDLS), and halogen lamps are existing technologies and will not be described in detail here. In other embodiments, the light source generator 11 can be used to provide other types of light sources. The type of light source can be adjusted according to the actual situation and is not limited here.

[0038] In this embodiment, the wavelength processor 12 is used to discretize the illumination light provided by the light source generator 11 into first rays with different center wavelengths. Specifically, the wavelength processor 12 discretizes the broadband light source provided by the light source generator 11 into narrow band rays with different center wavelengths. The wavelength processor 12 can be selected from one or more of a grating wavelength selector, a color wheel device, or a monochromator, or other types of wavelength processors can be selected, which are not limited here.

[0039] In other embodiments, if the light source provided by the light source generator 11 already meets the requirements, the wavelength processor 12 can be left idle and will not process the illumination light, that is, the illumination light provided by the light source generator 11 is directly transmitted to the imaging optical path 2.

[0040] Imaging optical path 2 processes the first light beam, focusing the processed light onto the surface of the test area of ​​the sample 200, and collects and transmits the reflected light generated by the sample 200 to the detection surface of the camera module 3. Imaging optical path 2 includes a first mirror group 21, a beam splitter 22, a first objective lens 23, and a first lens 24. The first mirror group 21 homogenizes the first light beam processed by the wavelength processor 12 to obtain a second light beam. The beam splitter 22 converts the second light beam into a third beam, which then illuminates the upper surface of the sample 200. A moving stage 5 for carrying the sample 200 is disposed below the first objective lens 23. The homogenization processing of the light is existing technology, and any homogenization method in the existing technology can be used according to the actual situation, without limitation.

[0041] In other embodiments, the light can be homogenized first and then discretized, that is, the positions of the wavelength processor 12 and the first mirror group 21 can be interchanged.

[0042] Specifically, the light transmission and conversion process of the imaging optical path 2 is as follows: the first lens group 21 homogenizes the first light processed by the wavelength processor 12 to obtain the second light, and couples the second light to the beam splitter 22. The third light formed after passing through the beam splitter 22 is transmitted along the first direction to the first objective lens 23 below. The magnification of the first objective lens 23 is selected according to the actual situation and is not limited here. The third light is a parallel beam, and the second light is perpendicular to the third light. The first objective lens 23 focuses the third light onto the first position on the surface of the test area of ​​the sample 200 to provide illumination to the sample 200. At the same time, the first objective lens 23 couples the reflected light obtained from the sample 200 to the beam splitter 22 along the second direction opposite to the first direction. The first lens 24 is used to cooperate with the first objective lens 23 to couple the reflected light on the beam splitter 22 to the detection surface of the camera module 3.

[0043] The beam splitting device 22 is selected from one or more of a beam splitting prism, a beam splitting lens, and a beam splitting grating. Beam splitting prisms, beam splitting lenses, and beam splitting gratings are existing technologies and will not be described in detail here.

[0044] To obtain film thickness distribution data over a larger area of ​​the sample 200 under test, in this embodiment, the imaging optical path 2 also includes a reflector 25 and a second objective lens 26, such as... Figure 1 As shown, the reflector 25 is used to receive the fourth light ray transmitted along a third direction via the beam splitter 22, and reflects the fourth light ray onto the second objective lens 26. The fourth light ray is focused onto a second position on the surface of the test area of ​​the sample 200. The magnification of the second objective lens 26 is selected according to actual conditions and is not limited here. In this embodiment, the third direction is set perpendicular to the first direction. In other embodiments, the third direction can be set according to actual conditions and is not limited here.

[0045] In order to adapt to different magnifications of the first objective lens 23 and the second objective lens 26, as well as to different test areas of the sample 200, the moving stage 5 can move laterally between a first position below the first objective lens 23 and a second position below the second objective lens 26, and move longitudinally along the vertical direction toward or away from the first objective lens 1022 and the second objective lens 109.

[0046] To obtain film thickness distribution data over a larger area of ​​the sample 200 under test, in another embodiment, the imaging optical path 2 further includes an objective lens switching stage 27 disposed below the beam splitter 22, such as... Figure 2 As shown, the first objective lens 23 and the second objective lens 26 are both mounted on the objective lens switching stage 27. Multiple third objective lenses 29 with different magnifications can also be added to the objective lens switching stage 27, which can realize the measurement of multiple different positions of the sample 200 to be tested and improve the measurement efficiency.

[0047] In semiconductor measurement and inspection, the high repetition area of ​​a circular light spot significantly impacts the inspection speed. To address this issue, a second mirror group 28 can be added between the first mirror group 21 and the beam splitter 22. The homogenized second light beam is a circular beam, and the second mirror group 28 shapes this circular beam into a uniform strip beam. At this point, the third light beam's spot is a strip beam, such as... Figure 5 As shown, using a strip beam can increase the coverage area of ​​a single scan, and the efficiency is significantly improved compared to a circular spot.

[0048] The second lens group 28 includes adjacent curved lens groups for compressing the second light rays in the X and Y directions, respectively. The curved lens group includes plano-concave cylindrical lenses and / or plano-convex cylindrical lenses. In this embodiment, as... Figure 3 As shown, the curved lens group includes a first plano-concave cylindrical lens 281, a first plano-convex cylindrical lens 282, a second plano-convex cylindrical lens 283, and a second plano-concave cylindrical lens 284. The focal lengths of the first plano-concave cylindrical lens 281, the first plano-convex cylindrical lens 282, the second plano-convex cylindrical lens 283, and the second plano-concave cylindrical lens 284, as well as the spacing between each cylindrical lens, are set according to actual conditions and are not limited here.

[0049] The first plano-concave cylindrical lens 281 and the first plano-convex cylindrical lens 282 have curvature changes in the Y direction, used to compress the spot size of the beam in the Y direction without converging or diverging light in the X direction. The second plano-convex cylindrical lens 283 and the second plano-concave cylindrical lens 284 have curvature changes in the X direction, used to compress the spot size of the beam in the X direction without converging or diverging light in the Y direction. The combined action of the first plano-concave cylindrical lens 281, the first plano-convex cylindrical lens 282, the second plano-convex cylindrical lens 283, and the second plano-concave cylindrical lens 284 is used to compress the circular spot in both the X and Y directions, changing the aspect ratio of the spot, thereby shaping the circular beam into a uniform strip beam. Moreover, since the spot can be compressed in both the X and Y directions, spots with different aspect ratios can be obtained, adapting to different measurement conditions.

[0050] In other embodiments, the second mirror group 28 can also shape a square light spot or other shapes into a strip light spot. The specific principle is similar to that described above, and will not be repeated here.

[0051] Camera module 3 is used to collect and image the reflected light transmitted from imaging optical path 2 to its detection surface, so as to obtain the reflected light image of the sample 200 under illumination of different wavelengths of light.

[0052] Camera module 3 can be selected from one or more of an area scan camera, a line scan camera, and a TDI camera. In this embodiment, when the second lens group 28 is not provided in the imaging optical path 2, camera module 3 is an area scan camera; when the second lens group 28 is provided in the imaging optical path 2, the camera is a line scan camera or a TDI camera. In other embodiments, the choice of camera can be set according to the actual situation, and is not limited here.

[0053] Image processing and calculation module 4 is used to process and calculate the obtained reflected light image to obtain the film thickness distribution image of the test area of ​​the sample. Image processing and calculation module 4 includes image processing unit 41 and measurement system 42. Image processing unit 41 is used to process the reflected light image, and the film thickness distribution image is calculated by measurement system 42 after processing of the reflected light image.

[0054] When measuring the film thickness of the entire sample 200, the image processing unit 41 first stitches together the acquired reflected light images to obtain multiple full-film images of the sample 200 under illumination at different wavelengths. The total grayscale value of a single point (the size of which can be set, with a minimum of a single pixel in the image) in each full-film image is selected as the relative light intensity value, or the relative light intensity value is converted into a relative reflectance value. This yields the relative light intensity or relative reflectance value of that single point under different wavelengths. Then, the measurement system 42 processes the discrete relative light intensity or relative reflectance values. The relative light intensity curve or relative reflectance curve is obtained by fitting, and the film thickness value of the single point is calculated from the relative light intensity curve and / or relative reflectance curve. In this way, each single point in the test area is measured sequentially to obtain the film thickness value at different positions of the whole sheet, thereby obtaining the film thickness distribution image of the whole sheet of the test sample 200. Even for films with uneven thickness, the thickness distribution can be clearly obtained from the distribution image. Compared with the method of averaging single-point measurements, this method can obtain the film thickness distribution image of the whole sheet of the test sample 200, which can improve the measurement accuracy of film thickness.

[0055] The method of calculating the film thickness distribution image from the reflected light image of the test area of ​​the sample 200 is existing technology and will not be elaborated here. You can refer to the method for calculating the film thickness distribution image disclosed in the article "Detection Device and Method for Micro-area Imaging of Film Thickness" published by Chinese Patent Application Publication No. CN112556584A, or refer to the film thickness measurement method in the article "Semiconductor Measurement System, Measurement Method and Storage Medium" published by Chinese Patent Grant Announcement No. CN117781903B, or use other methods in the prior art. There are no restrictions here.

[0056] If the measurement is of the film thickness of the test area of ​​the sample 200, i.e., not a full-sheet measurement, the choice can be made as to whether to first stitch the reflected light image. If the test area is small, image stitching is not required. If the test area is large, image stitching is required.

[0057] A full-size, high-precision semiconductor measurement and inspection system 100 is used to measure film thickness as follows:

[0058] Step 1: Place the sample 200 to be tested onto the stage 5 and switch the first objective lens 23 to the desired magnification;

[0059] Step 2: The light source generator 11 provides a variety of illumination rays with different center wavelengths, and the wavelength processor 12 discretizes the illumination rays provided by the light source generator 11 into first rays with different center wavelengths;

[0060] Step 3: Imaging optical path 2 processes the first light ray to obtain the third light ray. The third light ray is focused onto the surface of the test area of ​​the test sample 200, and the reflected light generated by the test sample 200 is collected and transmitted to the detection surface of camera module 3.

[0061] Step 4: Camera module 3 acquires and images the reflected light transmitted from imaging optical path 2 to its detection surface to obtain reflected light images of the sample 200 under illumination of different wavelengths of light;

[0062] Step 5: The image processing and calculation module 4 processes and calculates the obtained reflected light image to obtain the film thickness distribution image of the test area of ​​the sample.

[0063] In other embodiments, the measurement and detection system provided in this solution can also be used to detect defects and measure line width in the test area of ​​the sample 200. An image algorithm processing unit 43 is added to the image processing and calculation module 4. The image algorithm processing unit 43 can identify the image features of the test area, such as the size and type of defects and the line width. The measurement process is similar to that described above and will not be repeated here. The algorithm processing unit 43 is prior art and can be designed using existing technology.

[0064] The above descriptions are merely some embodiments of this utility model. For those skilled in the art, various modifications and improvements can be made without departing from the inventive concept of this utility model, and all such modifications and improvements fall within the protection scope of this utility model.

Claims

1. A full-size, high-precision semiconductor measurement and testing system, characterized in that: It includes a light source module, an imaging optical path, a camera module, and an image processing and computing module; The light source module includes a light source generator that provides illumination light and a wavelength processor that processes the illumination light into a first light ray; The imaging optical path includes a first mirror group, a beam splitter, a first objective lens, and a first lens. The first mirror group homogenizes the first light beam to obtain a second light beam. The beam splitter converts the second light beam into a third light beam. The third light beam is transmitted along a first direction to the first objective lens below and illuminates a first position in the test area of ​​the sample. At the same time, the first objective lens couples the reflected light beam obtained from the sample to the beam splitter along a second direction opposite to the first direction. The first lens, in conjunction with the first objective lens, transmits the reflected light beam from the beam splitter to the detection surface of the camera module. The camera module acquires the reflected light transmitted to its detection surface by the imaging optical path and forms an image to obtain an image of the reflected light of the sample under the illumination of the third light. The image processing and calculation module includes an image processing unit that processes the reflected light image and a measurement system that calculates and measures the film thickness distribution image.

2. The full-size, high-precision semiconductor measurement and testing system as described in claim 1, characterized in that: A movable stage for carrying the sample to be tested is provided below the first objective lens, and the movable stage is capable of moving laterally and / or longitudinally.

3. The full-size, high-precision semiconductor measurement and testing system as described in claim 1, characterized in that: The imaging optical path also includes a reflector and a second objective lens. The reflector receives a fourth ray transmitted along a third direction via a beam splitter and directs the fourth ray onto the second objective lens.

4. The full-size, high-precision semiconductor measurement and testing system as described in claim 3, characterized in that: The imaging optical path also includes an objective lens switching stage disposed below the beam splitter, wherein the first objective lens and the second objective lens are both mounted on the objective lens switching stage.

5. The full-size, high-precision semiconductor measurement and testing system as described in claim 1, characterized in that: A second mirror group is provided between the first mirror group and the beam splitter to change the aspect ratio of the light spot.

6. The full-size, high-precision semiconductor measurement and testing system as described in claim 5, characterized in that: The second lens group includes adjacent curved lens groups for compressing the second light rays in the X and Y directions, respectively. The curved lens group includes plano-concave cylindrical lenses and / or plano-convex cylindrical lenses.

7. The full-size, high-precision semiconductor measurement and testing system as described in claim 6, characterized in that: The curved lens group includes a first plano-concave cylindrical lens, a first plano-convex cylindrical lens, a second plano-convex cylindrical lens, and a second plano-concave cylindrical lens.

8. The full-size, high-precision semiconductor measurement and testing system as described in claim 1, characterized in that: The image processing and calculation module also includes an image algorithm processing unit capable of identifying image features of the area to be tested.

9. The full-size, high-precision semiconductor measurement and testing system as described in claim 1, characterized in that: The camera module is selected from one or more of the following: area scan camera, line scan camera, and TDI camera.

10. The full-size, high-precision semiconductor measurement and testing system as described in claim 1, characterized in that: The wavelength processor is selected from one or more of a grating wavelength selector, a color wheel device, or a monochromator.

Images