Extreme ultraviolet photoresist performance testing apparatus and method

Abstract

Disclosed are an extreme ultraviolet photoresist testing apparatus and method. The extreme ultraviolet photoresist testing apparatus comprises a substrate. At least one layer of film is disposed on the substrate, and at least one testing region is provided on the film. At least a portion of the film in the testing region is suspended. According to the present invention, the extreme ultraviolet photoresist can be characterized at near-atomic-scale resolution, and the use of the suspended film as a geometric structure of the substrate prevents charge accumulation during characterization, such that the line width and the line edge of the developed extreme ultraviolet photoresist can be characterized at near-atomic-scale resolution with low background noise. Moreover, according to the method, an electron energy loss spectrum of the extreme ultraviolet photoresist can be acquired and analyzed to determine whether all of the components of the extreme ultraviolet photoresist are uniformly distributed, and subnano-precision measurement is performed on the line edge roughness of the extreme ultraviolet photoresist, thereby accurately testing the performance of the extreme ultraviolet photoresist.

Description

Device and method for detecting performance of extreme ultraviolet photoresist Technical Field

[0001] The present invention relates to the field of chips, and in particular to an extreme ultraviolet photoresist performance detection device and method. Background Art

[0002] The International Roadmap for Devices and Systems (IRDS) states that in next-generation logic chip manufacturing processes, line edge roughness must be less than 0.5 nm and linewidth roughness less than 1 nm. Lithography is a core step in chip manufacturing. Due to the power limitations of EUV lithography systems, EUV photoresists face even more stringent requirements for performance (line roughness, sensitivity, and resolution). EUV photoresists are multi-component chemical materials, consisting of photoacid generators, alkaline quenchers, and protecting groups. These components are not uniformly distributed in thin-film EUV photoresists, making them prone to phase separation and aggregation, resulting in reduced exposure performance. The iterative development of EUV photoresists requires a characterization technique capable of characterizing developed photoresists with sub-nanometer precision. This will enable researchers to more precisely control the composition of EUV photoresists and accelerate their iterative development.

[0003] During the development of EUV photoresists, researchers typically use scanning electron microscopes (SEMs) to inspect the developed EUV photoresist and use the data obtained for iterative EUV photoresist development. However, existing SEMs cannot achieve sub-nanometer detection accuracy, and the charge accumulation caused by the interaction between the electron beam and the substrate during detection results in relatively high background noise in the detection image, affecting the unbiased measurement of EUV photoresist performance. When measuring the line edges of developed EUV photoresist using a SEM, the determination of line edges is affected by factors such as the electron acceleration voltage, nanostructure geometry, and substrate material. This makes it difficult to accurately identify the line edges of EUV photoresist with sub-nanometer precision, thus affecting the test results.

[0004] In summary, in the development and industrial use of EUV photoresist, there is still a lack of a detection method and device that can detect EUV photoresist with near-atomic resolution and filter out background noise generated by charge accumulation during detection. Technical issues

[0005] In view of the above-mentioned defects of the prior art, the technical problem to be solved by the present invention is to provide a detection method and device that can detect extreme ultraviolet photoresist with near-atomic resolution and can filter out charge accumulation and background noise generated during detection. Solution

[0006] Based on the above technical problems, the present invention provides an extreme ultraviolet photoresist detection device, including a substrate, at least one thin film is provided on the substrate, at least one detection area is provided on the thin film, and at least part of the detection area thin film is suspended.

[0007] Preferably, the hollow cross-sectional area of ​​the substrate below the suspended membrane gradually increases in a direction away from the suspended membrane.

[0008] Preferably, the substrate is a silicon wafer.

[0009] Preferably, the film is a silicon nitride film.

[0010] Preferably, a transfer layer is provided between the film and the substrate.

[0011] Preferably, the film thickness is set to 5nm-90nm.

[0012] The present invention also provides an extreme ultraviolet photoresist detection method, comprising the following steps:

[0013] 1) Spin coating EUV photoresist on the aforementioned EUV photoresist detection device to form a uniform EUV photoresist film layer;

[0014] 2) performing line exposure on the EUV photoresist film layer in step 1), so that the EUV photoresist film layer forms EUV photoresist nanowires;

[0015] 4) Analyzing and detecting the EUV photoresist nanowires.

[0016] Preferably, in step 2), an EUV lithography machine is used to perform line exposure on the EUV photoresist, or an electron beam and a scanning helium ion beam are used to expose the EUV photoresist on the suspended membrane.

[0017] Preferably, the method further comprises step 3): collapsing the EUV photoresist nanowires in step 2).

[0018] Preferably, in step 3), an atomic force microscope probe is used to knock down the EUV photoresist nanowire to cause the EUV photoresist nanowire to collapse, or,

[0019] The extreme ultraviolet photoresist film layer is infiltrated with a liquid having a high surface tension and dried to cause the nanowires having a height equal to the thickness of the extreme ultraviolet photoresist to collapse.

[0020] Preferably, in step 4), the EUV photoresist is analyzed and detected by the following steps:

[0021] 41) Measuring the line width and line edge of extreme ultraviolet photoresist;

[0022] 42) Scanning the EUV photoresist nanowires with a transmission electron microscope and collecting and analyzing an electron energy loss spectrum, inferring the local spatial composition of the EUV photoresist from the electron energy loss spectrum, and then detecting whether the components of the EUV photoresist are evenly distributed. Beneficial effects

[0023] (1) The present invention can characterize EUV photoresist at near-atomic resolution. The geometric structure using a suspended membrane as the substrate avoids charge accumulation during characterization, and the line width and line edge of the developed EUV photoresist can be measured and characterized at near-atomic resolution with low background noise. Furthermore, the method can collect electron energy loss spectra of the EUV photoresist, analyze whether the components of the EUV photoresist are evenly distributed, and measure the roughness of the EUV photoresist line edges with sub-nanometer precision, thereby accurately detecting the performance of the EUV photoresist.

[0024] (2) In the present invention, the hollow cross-sectional area of ​​the substrate below the suspended membrane gradually increases in the direction away from the suspended membrane. This allows the transmission electron microscope to reduce the possible contact volume between the substrate and the electron beam to a greater extent than a normal thick substrate when scanning with an electron beam, thereby minimizing the charge accumulation caused by the interaction between the electron beam and the substrate, resulting in a relatively low background noise in the detected image and a significant increase in detection accuracy to near the atomic level. In addition, this structure in which the hollow cross-sectional area gradually increases in the direction away from the suspended membrane is also more convenient to manufacture and can be directly manufactured using potassium hydroxide etching.

[0025] (3) The present invention can characterize EUV photoresist at near-atomic resolution. When the sum of the thickness of the silicon nitride film, the transfer layer, and the EUV photoresist is less than 60 nanometers, near-atomic resolution can be achieved when characterizing line widths and line edges. When the sum of the thickness of the silicon nitride film, the transfer layer, and the EUV photoresist is less than 100 nanometers, sub-nanometer resolution can be achieved. Without considering the EUV exposure performance of EUV photoresist in integrated circuit processing, EUV photoresist can also be spin-coated on a suspended membrane to measure the extreme exposure performance of EUV photoresist, such as the extreme resolution of EUV photoresist and the highest spatial density that can be achieved by EUV photoresist exposure.

[0026] (4) After the EUV photoresist is developed, a transmission electron microscope (TEM) is used to characterize and detect the EUV photoresist on the suspended membrane with non-destructive near-atomic resolution. During the characterization and detection, the high-voltage electron beam can penetrate the suspended membrane, avoiding charge accumulation during characterization, thereby reducing the background noise of the characterization pattern, and extracting and characterizing the line edge and line width of the developed photoresist pattern with sub-nanometer resolution. Since the line edge of the developed EUV photoresist is formed by the interaction of multiple factors at different scales, these factors include the type and energy of the exposure source, the monomers that make up the EUV photoresist, the photoacid generator, the alkaline quencher and the protecting group, the type of developer, etc., the unbiased near-atomic resolution TEM characterization of the EUV photoresist line edge helps to enhance the experimental traceability during the development of EUV photoresist and helps EUV photoresist researchers and developers to quickly and accurately control the EUV photoresist composition. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] FIG1 is a schematic structural diagram of a specific embodiment of the present invention;

[0028] FIG2 is a structure of an embodiment of the present invention without spin coating of extreme ultraviolet photoresist;

[0029] FIG3 is a structure of a spin-coated EUV photoresist and a transfer layer in Example 1 of the present invention;

[0030] FIG4 is a schematic diagram of the structure of FIG3 after being exposed and developed;

[0031] FIG5 is a structure of a spin-coated EUV photoresist without a transfer layer in Example 1 of the present invention;

[0032] FIG6 is a schematic diagram of the structure of FIG5 after being exposed and developed;

[0033] FIG7 is a schematic diagram of non-destructive near-atomic resolution characterization of an EUV photoresist on a freestanding membrane using a transmission electron microscope;

[0034] FIG8 is a schematic diagram of a data analysis method for extracting, characterizing, and detecting line edges of an EUV photoresist in an embodiment;

[0035] FIG9 is a scanning transmission electron microscope photograph of an untreated extreme ultraviolet photoresist;

[0036] FIG10 is a schematic structural diagram of the line edge extracted from the extreme ultraviolet photoresist of FIG9 using the method of FIG8;

[0037] FIG11 is a schematic diagram showing the relationship between coating thickness, exposure dose and line edge roughness in an embodiment;

[0038] FIG12 is a schematic diagram of collapsed EUV photoresist nanowires under a transmission electron microscope in an embodiment;

[0039] 13 is a schematic diagram of the highest spatial density that can be achieved when a helium ion beam is used to expose an EUV photoresist on a freestanding membrane in accordance with an embodiment;

[0040] FIG14 is a schematic diagram of the experimental structure for exposing and developing the EUV photoresist using a scanning helium ion beam. Modes for Carrying Out the Invention

[0041] The present invention will be described in detail below through specific examples. Example 1

[0042] As shown in FIG1 , this embodiment provides an extreme ultraviolet photoresist detection device, including a substrate, on which at least one thin film 3 is provided, on which at least one detection area is provided, and the detection area thin film 3 is at least partially suspended.

[0043] 1, 1 is the edge of the EUV photoresist line after development, 2 is the components of the EUV photoresist, such as a photoacid generator and an alkaline quencher; 3 is a suspended silicon nitride film.

[0044] The manufacturing steps of the suspended membrane are shown in Figure 2. A 5nm-90nm silicon nitride film is deposited on both sides of a silicon wafer using low-pressure chemical vapor deposition. A photoresist is spin-coated on the back of the silicon wafer. Selective exposure and development are performed according to the actual area of ​​the suspended membrane. The silicon nitride film is partially exposed. The silicon nitride film is plasma etched using the photoresist as a mask to expose the silicon wafer. The exposed silicon wafer is then etched with a potassium hydroxide solution. Finally, the suspended membrane structure shown in Figure 2 is manufactured.

[0045] As shown in Figure 2, the cross-sectional area of ​​the substrate's hollowing out below the suspended membrane gradually increases as it moves away from the membrane. This design significantly reduces the volume of interaction between the substrate and the electron beam during electron beam scanning, compared to a conventional thick silicon substrate. This minimizes charge accumulation caused by the interaction between the electron beam and the substrate, reduces background noise in the detection image, and significantly increases detection accuracy to near-atomic levels.

[0046] In this embodiment, a silicon wafer is used as a substrate and silicon nitride is used as a thin film. In other embodiments, other materials can be used to achieve the same technical effect. Example 2

[0047] In Example 2, the total thickness of the silicon nitride film plus the extreme ultraviolet photoresist is set to less than 60 nanometers; in this embodiment, the dimensions in Example 1 are limited to achieve a significant increase in detection accuracy. As shown in Figure 3, in this embodiment, we introduce a transfer layer 4, and after the extreme ultraviolet photoresist 5 is patterned by a photolithography process, the pattern is transferred to the transfer layer by dry etching, and the patterned transfer layer is used as a mask for the next step of etching. Figure 4 shows the structure of the extreme ultraviolet photoresist after being exposed and developed on the suspended membrane and the transfer layer. In this embodiment, the transfer layer and the extreme ultraviolet photoresist are spin-coated on the suspended membrane. In order to achieve a near-atomic resolution, the total thickness of the silicon nitride film, the transfer layer, and the extreme ultraviolet photoresist is set to less than 60 nanometers; in other embodiments, in order to achieve a sub-nanometer resolution, the total thickness of the silicon nitride film, the transfer layer, and the extreme ultraviolet photoresist is less than 100 nanometers. Of course, those skilled in the art will appreciate that the patterned EUV photoresist can be used directly as a mask to etch the thin films that comprise the integrated circuit. Figure 4 shows the structure of EUV photoresist on a freestanding membrane, and Figure 5 shows the structure of the EUV photoresist on the freestanding membrane after exposure and development. However, by introducing a patterned transfer layer to etch the thin films that comprise the integrated circuit, the operability of pattern transfer in the photolithography process can be increased. Example 3

[0048] In this embodiment, a specific method for detecting the performance index of extreme ultraviolet photoresist is provided. Specifically, it is a method for detecting the performance index of extreme ultraviolet photoresist with near-atomic resolution, which involves extracting the edge of the extreme ultraviolet photoresist line. The steps are as follows:

[0049] 1) Spin coating the EUV photoresist on the EUV photoresist detection device to form a uniform EUV photoresist film layer;

[0050] 2) performing line exposure on the EUV photoresist film layer in step 1), so that the EUV photoresist film layer forms EUV photoresist nanowires;

[0051] 4) Analyzing and detecting the EUV photoresist nanowires using a transmission electron microscope.

[0052] In this detection and characterization method, multiple tests and index characterizations can be performed. Without considering the extreme ultraviolet exposure performance of the extreme ultraviolet photoresist in integrated circuit processing, as shown in Figure 5, the extreme ultraviolet photoresist can be spin-coated on a suspended membrane to measure the extreme ultraviolet photoresist's ultimate exposure performance, such as the extreme ultraviolet photoresist's ultimate resolution and the maximum spatial density that the extreme ultraviolet photoresist can achieve. Similarly, if near-atomic resolution is required, it is recommended that the total thickness of the silicon nitride film plus the extreme ultraviolet photoresist be less than 60 nanometers; if sub-nanometer resolution is required, it is recommended that the total thickness of the silicon nitride film plus the extreme ultraviolet photoresist be less than 100 nanometers. Figure 6 shows the structure of the extreme ultraviolet photoresist after exposure and development on the suspended membrane. The extreme ultraviolet photoresist can be exposed using an extreme ultraviolet lithography machine or other exposure sources, such as electron beam lithography and scanning helium ion beam lithography.

[0053] After developing the EUV photoresist, a transmission electron microscope (TEM) was used to characterize the EUV photoresist on the freestanding membrane with near-atomic resolution, virtually non-destructively. As shown in Figure 7, in this embodiment, the image has a scanning field of view of 1.1 microns by 1.1 microns, a pixel count of 4096 by 4096, and an image resolution of approximately 0.27 nanometers. During characterization, the high-voltage electron beam can penetrate the freestanding membrane, preventing charge accumulation during characterization and reducing background noise in the characterization pattern. This allows for accurate, near-atomic resolution extraction of line edges and line widths from the developed photoresist pattern. Since the line edges of the developed EUV photoresist are formed by the interaction of multiple factors at different scales, including the type and energy of the exposure source, the monomers that make up the EUV photoresist, photoacid generators, alkaline quenchers and protecting groups, and the type of developer, unbiased, near-atomic resolution transmission electron microscopy characterization of the EUV photoresist line edges will help enhance the experimental traceability during EUV photoresist development and assist EUV photoresist researchers in quickly and accurately regulating the EUV photoresist composition. Example 4

[0054] In this embodiment, a specific implementation method is provided for the structure of embodiment 1 or embodiment 2, as well as embodiment 3, to perform near-atomic-level detection and characterization of the EUV photoresist using the EUV photoresist line edges obtained in embodiment 3. As shown in Figure 1, since EUV photoresist is a multi-component photoresist, when the EUV photoresist is sintered into a thin film, its component 2, such as the photoacid generator and the alkaline quencher, is not evenly distributed within the film, and phase separation and aggregation of the components are likely to occur, resulting in inconsistent exposure performance of the EUV photoresist at the sub-ten nanometer scale. Using the suspended membrane structure mentioned in the present invention, the extreme ultraviolet photoresist spin-coated on the suspended membrane can be line-exposed. The developed extreme ultraviolet photoresist is soaked with a liquid with high surface tension and dried to cause the nanowire 1 with a height equal to the thickness of the extreme ultraviolet photoresist to collapse, as shown in Figure 12. The width of the third collapsed rectangle from right to left in the figure is the 55-nanometer thickness of the extreme ultraviolet photoresist. After collapse, its height is the width of the nanowire after line exposure. When the width of the line-exposed nanowire in the figure is less than 10 nanometers, the geometric structure at its bottom is too narrow to support the stretching of the liquid surface tension, and the nanowire will collapse; or the nanowire can be knocked down by an atomic force microscope probe. After the EUV photoresist nanowires collapse after line exposure, they are scanned with a transmission electron microscope and the electron energy loss spectrum is collected and analyzed. The composition of the local space of the EUV photoresist is inferred from the electron energy loss spectrum, and the distribution map of each component of the EUV photoresist in the plane perpendicular to the two-dimensional direction of the EUV photoresist film is analyzed with sub-nanometer resolution, helping R&D personnel to accurately synthesize and iterate the EUV photoresist.

[0055] In this embodiment, if an EUV lithography machine is used to expose the EUV photoresist, the exposure result of the EUV photoresist on the suspended membrane is consistent with the exposure result of the EUV photoresist on the thick silicon substrate. The reason is as follows: because the energy of EUV photons is 92 electron volts, when incident on the EUV photoresist, secondary electrons with an energy of 80 electron volts will be generated. The energy of the secondary electrons with an energy of 80 electron volts drops to almost zero 5 nanometers away from the point where they are generated. Therefore, as long as the thickness of the transfer layer on the suspended membrane is greater than 5 nanometers, the exposure result of the EUV photoresist on the suspended membrane using the EUV lithography machine can be consistent with the exposure result on the thick silicon substrate.

[0056] When an electron beam and a scanning helium ion beam are used to expose an EUV photoresist on a suspended membrane, the forward-scattered electrons generated by the interaction of the high-energy electron beam or helium ion beam with the EUV photoresist will play a major role in the exposure of the EUV photoresist. Since the substrate is a suspended membrane, the backscattering effect when the electron beam or helium ion beam interacts with the substrate will be greatly reduced, and the spatial energy contrast during exposure will be maximized. This exposure method can be used to test the ultimate performance of the EUV photoresist, such as the ultimate resolution of the EUV photoresist and the highest spatial density that the EUV photoresist can achieve (Figure 13). In particular, when a scanning helium ion beam is used to expose the EUV photoresist, because the mass of helium ions is more than 7,000 times that of electrons, when the helium ions interact with the EUV photoresist, their motion trajectory will be more collimated than that of an electron beam. Under a specific operating space, the line edge of the cross-section of the secondary electron spatial energy distribution diagram corresponding to the development threshold generated by the interaction between helium ions and EUV photoresist can reach a roughness of 0.2 nanometers (Figure 14). Utilizing this characteristic, we can use a scanning helium ion beam to expose EUV photoresist on a suspended membrane, characterize the developed EUV photoresist using a transmission electron microscope, analyze its achievable minimum line edge roughness, and use the minimum line edge roughness to characterize the performance of the EUV photoresist. Example 5

[0057] In this embodiment, based on the first and second embodiments, after the photoresist is characterized with near-atomic resolution, the line edges of the photoresist are extracted using the data analysis method shown in Figure 8. Figure 9 is an unprocessed scanning transmission electron microscope photo, and Figure 10 is a picture of the extracted line edges obtained using the data analysis method shown in Figure 8. Based on this near-atomic resolution characterization method, the line edges of photoresists of different thicknesses and different exposure doses can be extracted and the line edge roughness can be calculated and statistically analyzed. As shown in Figure 11, when the designed exposure line width is 200 nanometers, the operating space of the sub-nanometer line edge roughness nanostructure can be produced using scanning helium ion exposure.

[0058] As shown in Figure 8, the following method can be used to calculate the line edge roughness: select the patterned photoresist area to be analyzed in the transmission electron microscope image, binarize the image to convert it into black and white, perform a connected area analysis on the image, and then extract the line edge of the photoresist. After extracting the outline of the line edge, use linear fitting to determine the center line of the line edge. According to the point-line distance formula, traverse all points, take the minimum value as the distance to that point, and calculate the standard deviation of each sampling point. If the line edge roughness is defined as a ,So The value of is the value of line edge roughness; if the line edge roughness is defined as 3 , then 3 The value of is the line edge roughness value. In the transmission electron microscope image, the patterned photoresist area to be analyzed is selected, the image is binarized to convert it into a black and white image, and the connected area analysis is performed on the image to extract the line edges of the photoresist.

[0059] Furthermore, after extracting the line edge pattern at near-atomic resolution as shown in FIG8 , the photoresist line edge roughness can be calculated according to the above steps. Using the above embodiments, the performance of EUV photoresist can be fully tested. Generally, EUV photoresist has three properties that require characterization: 1. resolution; 2. sensitivity; and 3. line edge roughness. While 1 and 2 can be easily measured using traditional methods, no method exists that can measure EUV photoresist line edges at near-atomic resolution, and furthermore, measure line edge roughness with sub-nanometer precision, thereby testing EUV photoresist performance.

[0060] Of course, in addition to the above embodiments, in other embodiments, we can also use the line edge measured by this method to conduct other studies, such as performing power spectrum density analysis on the line edge and extracting the initial value PSD(0) and correlation length of the line edge in the power spectrum density analysis. The PSD(0) value and the correlation length value can be used to analyze the effect of the change in the concentration of the photoacid generator on the exposure results of the extreme ultraviolet photoresist, the effect of the photoacid diffusion length on the exposure results of the extreme ultraviolet photoresist, the effect of the post-bake temperature on the exposure results of the extreme ultraviolet photoresist, etc. At the same time, multiple fractal analysis can be used to make a more accurate analysis of the exposure performance of the extreme ultraviolet photoresist, thereby optimizing the traceability of the extreme ultraviolet exposure experiment and helping R&D personnel to iteratively develop the extreme ultraviolet photoresist. Industrial Applicability

[0061] The above descriptions are merely preferred embodiments of the present invention. All equivalent changes and modifications made within the scope of the claims of the present invention shall fall within the scope of the claims of the present invention.

Claims

1. An extreme ultraviolet photoresist detection device, characterized in that: The invention comprises a substrate, on which at least one layer of film is arranged, on which at least one detection area is arranged, and at least a part of the detection area film is suspended.

2. The extreme ultraviolet photoresist detection device according to claim 1, characterized in that: The hollow cross-sectional area of ​​the substrate below the suspended membrane gradually increases in a direction away from the suspended membrane.

3. The extreme ultraviolet photoresist detection device according to claim 1, characterized in that: The film is configured as a silicon nitride film.

4. The extreme ultraviolet photoresist detection device according to claim 1, characterized in that: A transfer layer is arranged between the film and the substrate.

5. The extreme ultraviolet photoresist detection device according to any one of claims 1 to 4, characterized in that: The film thickness is set to be 5nm-90nm.

6. A method for detecting extreme ultraviolet photoresist, characterized in that: The following steps are involved: 1) Spin coating an EUV photoresist on the EUV photoresist detection device as claimed in any one of claims 1 to 6 to form a uniform EUV photoresist film layer; 2) performing line exposure on the EUV photoresist film layer in step 1) so that the EUV photoresist film layer forms EUV photoresist nanowires; 4) Analyzing and detecting the EUV photoresist nanowires.

7. The method for detecting extreme ultraviolet photoresist according to claim 6, wherein: In the step 2), an EUV photolithography machine is used to perform line exposure on the EUV photoresist, or an electron beam or a scanning helium ion beam is used to expose the EUV photoresist on the suspended membrane.

8. The method for detecting extreme ultraviolet photoresist as claimed in claim 6, characterized in that: The method further comprises step 3): collapsing the extreme ultraviolet photoresist nanowires in step 2).

9. The method for detecting extreme ultraviolet photoresist as claimed in claim 8, characterized in that: In the step 3), an atomic force microscope probe is used to knock down the EUV photoresist nanowires to cause them to collapse, or a liquid with high surface tension is used to infiltrate and dry the EUV photoresist film layer to cause the nanowires with a height equal to the thickness of the EUV photoresist to collapse.

10. The method for detecting extreme ultraviolet photoresist according to claim 9, characterized in that: In the step 4), the EUV photoresist is analyzed and detected by the following steps: 41) Measuring the line width and line edge of extreme ultraviolet photoresist; 42) Scanning the EUV photoresist nanowires with a transmission electron microscope and collecting and analyzing the electron energy loss spectrum, inferring the local spatial composition of the EUV photoresist from the electron energy loss spectrum, and then detecting whether the components of the EUV photoresist are evenly distributed.

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