Chromatic aberration detection method for wafer film layer
By using a first light source and a second light source with different absorption capabilities to scan the wafer film layer, and then acquiring and comparing grayscale data, the problem of large color difference detection error in the wafer film layer in the prior art is solved, and accurate color difference and thickness detection is achieved.
Patent Information
- Application Number
- CN202511711527.X
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-11-20
- Publication Date
- 2026-02-24
AI Technical Summary
Existing technologies for detecting color differences in wafer films have significant errors, making accurate detection impossible.
By identifying a first light source and a second light source with different absorption capabilities, scanning the wafer film layer respectively, and acquiring and comparing grayscale data under the first and second light sources, color difference detection is achieved.
It enables precise color difference detection of wafer film layers, and can more accurately determine the degree of color difference and thickness at different locations of the film layer.
Smart Images
Figure CN121558646A_ABST
Abstract
Description
Technical Field
[0001] This application relates to the field of wafer inspection technology, and in particular to a method for detecting color difference in wafer films. Background Technology
[0002] In current optical defect detection of SiC film, the optical detection of each station mainly uses imaging technology to output the reflected light intensity of the object being inspected as a quantitative grayscale value. By comparing the grayscale value with that of a standard image, the difference between adjacent core particles is mainly used to determine whether there is a color difference abnormality in the whole wafer. However, the judgment result has a large error.
[0003] Application content
[0004] This application provides a method for detecting color difference in wafer films to achieve accurate color difference detection of the wafer films to be tested.
[0005] According to one aspect of this application, a method for detecting color difference in a wafer film layer is provided, the method comprising:
[0006] The first light source and the second light source are determined based on the film characteristics of the wafer to be tested; wherein, the absorption capacity of the film layer of the wafer to be tested to the first light source is different from the absorption capacity of the film layer of the wafer to be tested to the second light source.
[0007] The wafer film layers to be tested are scanned using a first light source and a second light source, respectively.
[0008] Determine the first grayscale data of the wafer film layer to be detected under the first light source scan and the second grayscale data of the wafer film layer to be detected under the second light source scan;
[0009] Color difference detection is performed on the wafer film layer to be tested based on the first grayscale data and the second grayscale data.
[0010] Furthermore, the wafer film layer under test has the strongest absorption capacity for the first light source;
[0011] The wafer film layer under test has the weakest absorption capacity for the second light source.
[0012] Furthermore, determining the first grayscale data of the wafer film layer to be detected under the first light source scan and the second grayscale data of the wafer film layer to be detected under the second light source scan includes:
[0013] Acquire the first emission data of the wafer film layer to be detected under the first light source scan and the second emission data of the wafer film layer to be detected under the second light source scan;
[0014] The first grayscale data of the wafer film layer to be detected under the first light source scanning is determined based on the first luminescence data.
[0015] The second grayscale data of the wafer film layer to be detected under the second light source scanning is determined based on the second emission data.
[0016] Furthermore, the first luminescence data includes at least one of the first chromaticity data and the first luminance data;
[0017] The second luminance data includes at least one of the second chromaticity data and the second luminance data.
[0018] Furthermore, based on the first emission data, the first grayscale data of the wafer film layer to be detected under the first light source scanning is determined, including:
[0019] The first grayscale data of the wafer film layer to be detected under the first light source scanning is determined based on the correspondence between the first luminescence data and the pre-set first preset luminescence data and the first preset grayscale data.
[0020] Furthermore, based on the correspondence between the first emission data and the pre-set first preset emission data and first preset grayscale data, the first grayscale data of the wafer film layer to be detected under the first light source scanning is determined, including:
[0021] The first grayscale data of the wafer film layer to be detected under the first light source scanning is determined by interpolation based on the correspondence between the first luminous data and the pre-set first preset luminous data and the first preset grayscale data.
[0022] Furthermore, based on the second emission data, the second grayscale data of the wafer film layer to be detected under the second light source scanning is determined, including:
[0023] The second grayscale data of the wafer film layer to be detected under the second light source scanning is determined based on the correspondence between the second luminescence data and the pre-set second preset luminescence data and the second preset grayscale data.
[0024] Furthermore, based on the correspondence between the second emission data and the pre-set second preset emission data and second preset grayscale data, the second grayscale data of the wafer film layer to be detected under the second light source scanning is determined, including:
[0025] The second grayscale data of the wafer film layer to be detected under the second light source scanning is determined by interpolation based on the correspondence between the second luminous data and the pre-set second preset luminous data and the second preset grayscale data.
[0026] Furthermore, color difference detection is performed on the wafer film layer to be inspected based on the first grayscale data and the second grayscale data, including:
[0027] The color difference of the wafer film layer under test is detected by measuring the gray level difference between the first gray level data and the second gray level data at different locations.
[0028] Furthermore, the difference between the first grayscale data and the second grayscale data at different locations on the wafer film layer under test is used to perform color difference detection on the wafer film layer under test, including:
[0029] The correspondence between different locations and gray level differences is determined based on the gray level difference between the first gray level data and the second gray level data at different locations of the wafer film layer to be tested.
[0030] Color difference detection is performed on the wafer film layer to be tested based on the correspondence between different positions and grayscale differences, as well as the preset abnormal grayscale values.
[0031] The color difference detection method for wafer film layers provided in this application determines a first light source and a second light source based on the film layer characteristics of the wafer to be tested. The first and second light sources are then used to scan the wafer film layer to be tested, respectively, to determine the first grayscale data of the wafer film layer under the first light source scan and the second grayscale data under the second light source scan. Finally, color difference detection is performed on the wafer film layer based on the first and second grayscale data. Compared to the prior art's automatic optical inspection, which uses the color difference between adjacent chips to determine the degree of color difference in the wafer, this application uses a first light source and a second light source with different absorption capabilities to act on the wafer film layer to be tested. This allows for the determination of the degree of color difference at different locations of the wafer film layer by observing the different brightness levels at the same location under the first and second light sources, thus achieving accurate color difference detection of the wafer film layer.
[0032] It should be understood that the description in this section is not intended to identify key or essential features of the embodiments of this application, nor is it intended to limit the scope of this application. Other features of this application will become readily apparent from the following description. Attached Figure Description
[0033] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.
[0034] Figure 1 This is a flowchart of a color difference detection method for a wafer film layer according to an embodiment of this application;
[0035] Figure 2 This is a schematic diagram of a light source scanning a wafer film layer according to an embodiment of this application;
[0036] Figure 3 This is a schematic diagram of the light emission of a wafer film layer under scanning by a first light source according to an embodiment of this application;
[0037] Figure 4 This is a schematic diagram of the light emission of a wafer film layer under scanning by a second light source according to an embodiment of this application;
[0038] Figure 5 This is to implement a correspondence curve between different positions and grayscale data provided in the embodiments of this application;
[0039] Figure 6 This is to realize the correspondence curve between different positions and grayscale difference values provided in the embodiments of this application. Detailed Implementation
[0040] To enable those skilled in the art to better understand the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present application, and not all embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative effort should fall within the scope of protection of the present application.
[0041] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of this application described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.
[0042] This application provides a method for detecting color difference in wafer films. Figure 1 This is a flowchart of a color difference detection method for a wafer film layer according to an embodiment of this application, with reference to... Figure 1 Methods for detecting color difference in wafer films include:
[0043] S110. Determine the first light source and the second light source based on the film characteristics of the wafer to be tested; wherein the absorption capacity of the wafer film to be tested to the first light source is different from the absorption capacity of the wafer film to be tested to the second light source.
[0044] Specifically, the characteristics of a wafer under test can be determined by applying multiple sets of light sources of different wavelengths to the same film layer. These film layer characteristics may include light absorption capacity. Based on these characteristics, a first light source and a second light source with different absorption capacities can be identified. For example, the first light source can be the one with the strongest absorption capacity of the wafer's film layer, and the second light source can be the one with the weakest absorption capacity. For example, different film layers forming the wafer under test can be tested according to the specific circumstances.
[0045] S120. Scan the wafer film layer to be detected using the first light source and the second light source respectively.
[0046] Specifically, Figure 2 This is a schematic diagram of a light source scanning wafer film layer according to an embodiment of this application, with reference to... Figure 2 By scanning the wafer film 1 with a first light source and a second light source that have different absorption capabilities, the wafer film 1 can be made to exhibit different luminous brightness at the same position.
[0047] S130. Determine the first grayscale data of the wafer film layer to be detected under the first light source scan and the second grayscale data of the wafer film layer to be detected under the second light source scan.
[0048] Specifically, the first emission data of the wafer film layer to be detected under the scanning of the first light source and the second emission data of the wafer film layer to be detected under the scanning of the second light source can be obtained firstly. Then, the first grayscale data of the wafer film layer to be detected under the scanning of the first light source can be determined based on the first emission data, and the second grayscale data of the wafer film layer to be detected under the scanning of the second light source can be determined based on the second emission data.
[0049] S140. Perform color difference detection on the wafer film layer to be tested based on the first grayscale data and the second grayscale data.
[0050] Specifically, the degree of color difference of the wafer film layer under test can be detected based on the grayscale difference between the first grayscale data and the second grayscale data at different locations. That is, the degree of color difference at different locations of the film layer under the first and second light sources can be used to determine the different brightness levels observed at the same location under different light sources.
[0051] The color difference detection method for wafer film layers provided in this application determines a first light source and a second light source based on the film layer characteristics of the wafer to be tested. The first and second light sources are then used to scan the wafer film layer to be tested, respectively, to determine the first grayscale data of the wafer film layer under the first light source scan and the second grayscale data under the second light source scan. Finally, color difference detection is performed on the wafer film layer based on the first and second grayscale data. Compared to the prior art's automatic optical inspection, which uses the color difference between adjacent chips to determine the degree of color difference in the wafer, this application uses a first light source and a second light source with different absorption capabilities to act on the wafer film layer to be tested. This allows for the determination of the degree of color difference at different locations of the wafer film layer by observing the different brightness levels at the same location under the first and second light sources, thus achieving accurate color difference detection of the wafer film layer.
[0052] Furthermore, Figure 3 This is a schematic diagram of the light emission of a wafer film layer under scanning by a first light source, according to an embodiment of this application. Figure 4 This is a schematic diagram of the light emission of a wafer film layer under scanning by a second light source according to an embodiment of this application. (Refer to...) Figure 3 and Figure 4 The wafer film layer under test has the strongest absorption capacity for the first light source;
[0053] The wafer film layer under test has the weakest absorption capacity for the second light source.
[0054] Specifically, the first light source is set to be the light source with the strongest absorption capacity of the wafer film layer to be tested, and the second light source is set to be the light source with the weakest absorption capacity of the wafer film layer to be tested. This makes the brightness difference of the wafer film layer to be tested at the same position more obvious under the first light source and the second light source, thereby realizing accurate color difference detection of the wafer film layer to be tested, and can more accurately determine the thickness of the wafer film layer at different positions.
[0055] Furthermore, determining the first grayscale data of the wafer film layer to be detected under the first light source scan and the second grayscale data of the wafer film layer to be detected under the second light source scan includes:
[0056] Acquire the first emission data of the wafer film layer to be detected under the first light source scan and the second emission data of the wafer film layer to be detected under the second light source scan;
[0057] The first grayscale data of the wafer film layer to be detected under the first light source scanning is determined based on the first luminescence data.
[0058] The second grayscale data of the wafer film layer to be detected under the second light source scanning is determined based on the second emission data.
[0059] Specifically, by converting the first luminescence data of the wafer film layer to be tested into first grayscale data, and the second luminescence data of the wafer film layer to be tested into second grayscale data, the brightness of the wafer film layer to be tested at the same position under the first light source and the second light source can be compared more conveniently and intuitively. For example, the first grayscale data of the wafer film layer to be tested under the first light source scan is determined according to the correspondence between the first luminescence data and the pre-set first preset luminescence data and the first preset grayscale data, and the second grayscale data of the wafer film layer to be tested under the second light source scan is determined according to the correspondence between the second luminescence data and the pre-set second preset luminescence data and the second preset grayscale data.
[0060] Furthermore, the first luminescence data includes at least one of the first chromaticity data and the first luminance data;
[0061] The second luminance data includes at least one of the second chromaticity data and the second luminance data.
[0062] Among them, at least one can be understood as one or more. For example, the luminance data may include only chromaticity data, only luminance data, or both chromaticity data and luminance data.
[0063] Specifically, the first grayscale data of the wafer film layer to be detected under the scanning of the first light source is determined based on at least one of the first chromaticity data and the first brightness data, and the second grayscale data of the wafer film layer to be detected under the scanning of the second light source is determined based on at least one of the second chromaticity data and the second brightness data.
[0064] Furthermore, based on the first emission data, the first grayscale data of the wafer film layer to be detected under the first light source scanning is determined, including:
[0065] The first grayscale data of the wafer film layer to be detected under the first light source scanning is determined based on the correspondence between the first luminescence data and the pre-set first preset luminescence data and the first preset grayscale data.
[0066] Specifically, if there is a first preset luminous data that is the same as the first luminous data in the predetermined correspondence between the first preset luminous data and the first preset grayscale data, then the first preset grayscale data corresponding to the first luminous data can be directly determined as the first grayscale data of the wafer film layer to be detected under the scanning of the first light source; if there is no first preset luminous data that is the same as the first luminous data in the predetermined correspondence between the first preset luminous data and the first preset grayscale data, then the first grayscale data of the wafer film layer to be detected under the scanning of the first light source can be determined by interpolation.
[0067] Furthermore, based on the correspondence between the first emission data and the pre-set first emission data and first grayscale data, the first grayscale data of the wafer film layer to be detected under the first light source scanning is determined, including:
[0068] The first grayscale data of the wafer film layer to be detected under the first light source scanning is determined by interpolation based on the correspondence between the first luminous data and the pre-set first preset luminous data and the first preset grayscale data.
[0069] Specifically, if there is no first preset light-emitting data that is the same as the first light-emitting data in the pre-determined correspondence between the first preset light-emitting data and the first preset gray-scale data, then the first gray-scale data of the wafer film layer to be detected under the first light source scanning is determined by interpolation of the first preset gray-scale data corresponding to the two first preset light-emitting data adjacent to the first light-emitting data.
[0070] Furthermore, based on the second emission data, the second grayscale data of the wafer film layer to be detected under the second light source scanning is determined, including:
[0071] The second grayscale data of the wafer film layer to be detected under the second light source scanning is determined based on the correspondence between the second luminescence data and the pre-set second preset luminescence data and the second preset grayscale data.
[0072] Specifically, if there is a second preset luminous data that is the same as the second luminous data in the predetermined correspondence between the second preset luminous data and the second preset grayscale data, then the second preset grayscale data corresponding to the second luminous data can be directly determined as the second grayscale data of the wafer film layer to be detected under the second light source scanning; if there is no second preset luminous data that is the same as the second luminous data in the predetermined correspondence between the second preset luminous data and the second preset grayscale data, then the second grayscale data of the wafer film layer to be detected under the second light source scanning can be determined by interpolation.
[0073] Furthermore, based on the correspondence between the second emission data and the pre-set second preset emission data and second preset grayscale data, the second grayscale data of the wafer film layer to be detected under the second light source scanning is determined, including:
[0074] The second grayscale data of the wafer film layer to be detected under the second light source scanning is determined by interpolation based on the correspondence between the second luminous data and the pre-set second preset luminous data and the second preset grayscale data.
[0075] Specifically, if there is no second preset light-emitting data that is the same as the second light-emitting data in the pre-determined correspondence between the second preset light-emitting data and the second preset gray-scale data, then the second gray-scale data of the wafer film layer to be detected under the second light source scanning is determined by interpolation of the second preset gray-scale data corresponding to the two second preset light-emitting data adjacent to the second light-emitting data.
[0076] Furthermore, color difference detection is performed on the wafer film layer to be inspected based on the first grayscale data and the second grayscale data, including:
[0077] The color difference of the wafer film layer under test is detected by measuring the gray level difference between the first gray level data and the second gray level data at different locations.
[0078] Specifically, the correspondence between different positions and grayscale differences can be determined based on the grayscale difference between the first grayscale data and the second grayscale data at different locations on the wafer film layer to be tested. Color difference detection can then be performed on the wafer film layer to be tested based on the correspondence between different positions and grayscale differences, as well as the preset abnormal grayscale.
[0079] Furthermore, based on the difference between the first grayscale data and the second grayscale data at different locations of the wafer film layer under test, color difference detection is performed on the wafer film layer under test, including:
[0080] The correspondence between different locations and gray level differences is determined based on the gray level difference between the first gray level data and the second gray level data at different locations of the wafer film layer to be tested.
[0081] Color difference detection is performed on the wafer film layer to be tested based on the correspondence between different positions and grayscale differences, as well as the preset abnormal grayscale values.
[0082] Specifically, Figure 5 This implements a correspondence curve between different positions and grayscale data provided in the embodiments of this application. Figure 6 This implements a correspondence curve between different positions and grayscale differences provided in the embodiments of this application, such as... Figure 5 and Figure 6 As shown, the curves corresponding to different positions of the wafer film layer under test and the first grayscale data can be obtained, i.e. Figure 5 The red curve shown, and the corresponding curves of different positions of the wafer film layer to be tested and the second grayscale data, are as follows: Figure 5 The blue curve shown can be used to determine the grayscale difference between the first and second grayscale data at different locations based on the correspondence curves between different locations and the first grayscale data, and between different locations and the second grayscale data. This allows for the determination of the correspondence curves between different locations and the grayscale difference, as shown in the figure. Figure 6 The blue curve is shown. Then, based on the correspondence between different positions and grayscale differences, and the preset abnormal grayscale values, color difference detection is performed on the wafer film layer to be tested. This determines whether the color difference at different positions of the wafer film layer meets the requirements, and also whether the thickness uniformity of the wafer film layer meets the requirements. Figure 6The blue curve above the red dashed line represents the portion where color difference detection fails to meet requirements, while the blue curve below the red dashed line represents the portion where color difference detection meets requirements. The preset abnormal grayscale can be determined based on the color difference standard of the wafer film layer to be inspected. For example, if the preset color difference standard of the wafer film layer to be inspected is low, a larger preset abnormal grayscale can be set; if the preset color difference standard of the wafer film layer to be inspected is high, a smaller preset abnormal grayscale can be set.
[0083] It should be understood that the various forms of processes shown above can be used to rearrange, add, or delete steps. For example, the steps described in this application can be executed in parallel, sequentially, or in different orders, as long as the desired result of the technical solution of this application can be achieved, and this is not limited herein.
[0084] The specific embodiments described above do not constitute a limitation on the scope of protection of this application. Those skilled in the art should understand that various modifications, combinations, sub-combinations, and substitutions can be made according to design requirements and other factors. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this application should be included within the scope of protection of this application.
Claims
1. A method for detecting color difference in wafer films, characterized in that, include: A first light source and a second light source are determined based on the film characteristics of the wafer to be tested; wherein the absorption capacity of the film layer of the wafer to be tested to the first light source is different from the absorption capacity of the film layer of the wafer to be tested to the second light source. The wafer film layer to be detected is scanned using the first light source and the second light source, respectively. Determine the first grayscale data of the wafer film layer to be detected under the first light source scan and the second grayscale data of the wafer film layer to be detected under the second light source scan; Color difference detection is performed on the wafer film layer to be tested based on the first grayscale data and the second grayscale data.
2. The method for detecting color difference in wafer films according to claim 1, characterized in that, The wafer film layer to be tested has the strongest absorption capacity for the first light source; The wafer film layer to be tested has the weakest absorption capacity for the second light source.
3. The method for detecting color difference in wafer films according to claim 1, characterized in that, Determining the first grayscale data of the wafer film layer to be inspected under the scanning of the first light source and the second grayscale data of the wafer film layer to be inspected under the scanning of the second light source includes: Acquire the first emission data of the wafer film layer to be detected under the scanning of the first light source and the second emission data of the wafer film layer to be detected under the scanning of the second light source; The first grayscale data of the wafer film layer to be detected under the scanning of the first light source is determined based on the first luminescence data. The second grayscale data of the wafer film layer to be detected under the second light source scan is determined based on the second light emission data.
4. The method for detecting color difference in wafer films according to claim 3, characterized in that, The first luminescence data includes at least one of the first chromaticity data and the first luminance data; The second luminance data includes at least one of the second chromaticity data and the second luminance data.
5. The method for detecting color difference in wafer films according to claim 3, characterized in that, The first grayscale data of the wafer film layer to be detected under the first light source scan is determined based on the first luminescence data, including: The first grayscale data of the wafer film layer to be detected under the first light source scanning is determined based on the correspondence between the first light emission data and the first preset light emission data and the first preset grayscale data.
6. The method for detecting color difference in wafer films according to claim 5, characterized in that, The first grayscale data of the wafer film layer to be detected under the first light source scanning is determined based on the correspondence between the first luminous data and the first preset luminous data and the first preset grayscale data, including: The first grayscale data of the wafer film layer to be detected under the first light source scanning is determined by interpolation based on the correspondence between the first light emission data and the first preset light emission data and the first preset grayscale data.
7. The method for detecting color difference in wafer films according to claim 3, characterized in that, The second grayscale data of the wafer film layer to be detected under the second light source scan is determined based on the second luminescence data, including: The second preset grayscale data of the wafer film layer to be detected under the second light source scanning is determined based on the correspondence between the second light emission data and the pre-set second preset light emission data and the second preset grayscale data.
8. The method for detecting color difference in wafer films according to claim 7, characterized in that, The second grayscale data of the wafer film layer to be detected under the second light source scanning is determined based on the correspondence between the second luminous data and the pre-set second preset luminous data and the second preset grayscale data, including: The second grayscale data of the wafer film layer to be detected under the second light source scanning is determined by interpolation based on the correspondence between the second light emission data and the pre-set second preset light emission data and the second preset grayscale data.
9. The method for detecting color difference in wafer films according to claim 1, characterized in that, Color difference detection is performed on the wafer film layer to be tested based on the first grayscale data and the second grayscale data, including: The color difference of the wafer film layer under test is detected based on the gray level difference between the first gray level data and the second gray level data at different positions.
10. The method for detecting color difference in wafer films according to claim 9, characterized in that, Color difference detection is performed on the wafer film layer under test based on the difference between the first grayscale data and the second grayscale data at different locations, including: Based on the gray level difference between the first gray level data and the second gray level data at different locations of the wafer film layer to be tested, the correspondence between different locations and gray level differences is determined. Based on the correspondence between different positions and grayscale differences, and the preset abnormal grayscale, the color difference of the wafer film layer to be tested is detected.