Electron beam detection system

Abstract

This invention provides an electron beam detection system, comprising: an electron source configured to generate a main electron beam; a beam splitter configured to generate sub-beams from the main electron beam; a focusing device configured to focus the main electron beam onto an optimized sub-region of the beam splitter, wherein the optimized sub-region is smaller than the total area of ​​the beam splitter; and a mask comprising a blocking region and an opening region, the blocking region being configured to block a first plurality of the sub-beams, and the opening region being configured to allow a second plurality of the sub-beams to pass through the mask.

Description

Technical Field

[0001] The embodiments of this utility model relate to an electron beam detection system. Background Technology

[0002] In the semiconductor device manufacturing industry, as circuit patterns become increasingly complex, the need for high-resolution inspection systems capable of accurately detecting and resolving defects has become more pronounced. Electron multi-beam inspection systems offer a promising approach for high-resolution inspection and defect detection. These systems provide methods for analyzing complex patterns, such as those formed using extreme ultraviolet lithography systems, enabling rapid and accurate identification of nanoscale defects. This contributes to improved yield and performance of semiconductor devices. Utility Model Content

[0003] This invention provides an electron beam detection system, comprising: an electron source configured to generate a main electron beam; a beam splitter configured to generate sub-beams from the main electron beam; a focusing device configured to focus the main electron beam onto an optimized sub-region of the beam splitter, wherein the optimized sub-region is smaller than the total area of ​​the beam splitter; and a mask comprising a blocking region and an opening region, the blocking region being configured to block a first plurality of the sub-beams, and the opening region being configured to allow a second plurality of the sub-beams to pass through the mask.

[0004] This invention provides an electron beam detection system, comprising: an electron source; a focusing device configured to generate a main electron beam including an optimized beam irradiation region; a beam splitter having an area larger than the optimized beam irradiation region; and a reconfigurable multiple mask device including multiple selective masks. Attached Figure Description

[0005] The best understanding of the features of this disclosure will be achieved by reading the following detailed description in conjunction with the accompanying drawings. It should be noted that, according to industry standard practice, the various features are not drawn to scale. In fact, the dimensions of the various features may be arbitrarily increased or decreased for clarity of explanation.

[0006] Figure 1 This is a vertical cross-sectional view of an extreme ultraviolet lithography system according to various embodiments.

[0007] Figure 2 This is a vertical cross-sectional view of an electron beam detection system according to various embodiments.

[0008] Figure 3A This is a top view of a beam splitter configured as an aperture array according to various embodiments.

[0009] Figure 3BIt is a top view of a canopy having blocking areas and opening areas according to various embodiments.

[0010] Figure 4A This is a top view of a beam splitter having an electron beam focused onto an optimized beam irradiation region according to various embodiments.

[0011] Figure 4B This is a top view of a beam splitter having an electron beam focused onto an optimized beam irradiation region according to various embodiments.

[0012] Figure 4C This is a top view of a beam splitter having an electron beam focused onto an optimized beam irradiation region according to various embodiments.

[0013] Figure 5A It is a top view of a canopy having a reconfigurable partition system in a first configuration according to various embodiments.

[0014] Figure 5B It is in the second configuration according to various embodiments. Figure 5A A top view of the canopy.

[0015] Figure 6 This is a schematic diagram of an electron beam detection system including a reconfigurable multi-mask device with multiple selectable masks, according to various embodiments.

[0016] Figure 7 This is a flowchart illustrating the operation of a semiconductor substrate electron multibeam detection method according to various embodiments. Detailed Implementation

[0017] This disclosure provides numerous different embodiments or instances for implementing various features of this disclosure. Specific examples of components and arrangements are described below to simplify this disclosure. Of course, these are merely examples and are not intended to be limiting. For example, the following description of a first feature formed on or on a second feature may include embodiments in which the first and second features are formed in direct contact, and may also include embodiments in which additional features may be formed between the first and second features, thereby preventing direct contact between the first and second features. Furthermore, reference numerals and / or letters may be repeated throughout this disclosure in various examples. Such repetition is for simplicity and clarity and does not in itself indicate a relationship between the various embodiments and / or configurations discussed.

[0018] Furthermore, for ease of explanation, this document may use spatially relative terms such as “beneath,” “below,” “lower,” “above,” “upper,” and similar expressions to describe the relationship between one device or feature shown in the figures and another device or feature. These spatially relative terms are intended to encompass different orientations of the device in use or operation, in addition to those shown in the figures. The device may have other orientations (rotated 90 degrees or in other orientations), and the spatially relative descriptions used herein can be interpreted accordingly. Furthermore, the phrase “made of” may mean “including” or “consisting of.” In this disclosure, “one of A, B and C” means “A, B and / or C” (A, B, C, A and B, A and C, B and C or A, B and C), and unless otherwise stated, does not mean selecting an element from A, selecting an element from B and selecting an element from C.

[0019] The disclosed embodiments offer advantages by providing a semiconductor substrate electron multi-beam detection system and method with enhanced signal quality and increased throughput. In this regard, one method includes focusing a primary electron beam to generate a focused electron beam with an optimized beamillumination area. The focused electron beam is then struck by a beam splitter such that the optimized beamillumination area is smaller than the total area of ​​the beam splitter. Thus, the electron sub-beams generated by the beam splitter are directed only to the region of interest corresponding to the circuit element to be scanned. By focusing the optimized electron beam in this way, the electron current in the individual sub-beams is increased. A mask is also used to block sub-beams from regions outside the region of interest. This blocking reduces unwanted signals from regions outside the region of interest, thereby improving the performance of the electron multi-beam detection system.

[0020] Figure 1 This is a vertical cross-sectional view of an extreme ultraviolet (EUV) lithography system 100 having an EUV radiation source 102 according to various embodiments. The EUV lithography system 100 also includes an exposure device 202, such as a scanner, and an excitation laser source 300. Figure 1As shown, in some embodiments, the EUV radiation source 102 and the exposure device 202 are mounted on the main floor MF of the cleanroom, while the excitation laser source 300 is mounted in the base floor BF located below the main floor. The EUV radiation source 102 and the exposure device 202 are placed on base plates PP1 and PP2, respectively, via dampers DMP1 and DMP2. The EUV radiation source 102 and the exposure device 202 are coupled to each other by a coupling mechanism including a focusing unit 101.

[0021] The EUV lithography system 100 is designed to expose a resist layer formed on a substrate to EUV radiation. The resist layer is a material sensitive to EUV radiation. The EUV lithography system 100 employs an EUV radiation source 102 to generate EUV radiation, for example, EUV radiation with a wavelength range between about 1 nm and about 50 nm. In one example embodiment, the EUV radiation source 102 generates EUV radiation with a peak wavelength of about 13.5 nm. In this embodiment, the EUV radiation source 102 utilizes a laser-generated plasma mechanism to generate EUV radiation.

[0022] Exposure apparatus 202 includes various reflective optical elements, such as convex mirrors, concave mirrors, and plane mirrors. Exposure apparatus 202 also includes a mask holding mechanism with a mask stage, and a wafer holding mechanism (e.g., a substrate holding mechanism). EUV radiation generated by EUV radiation source 102 is guided by the reflective optical elements to a mask fixed on the mask stage (neither of which is in the same position as the substrate). Figure 1 (as shown in the image). In some embodiments, the mask stage includes an electrostatic chuck to secure the mask. Because gas molecules absorb EUV radiation, the EUV lithography system 100 is maintained in a vacuum or low-pressure environment to avoid EUV intensity loss.

[0023] In this disclosure, the terms "mask," "photomask," and "reticle" are used interchangeably. Similarly, the terms "resist" and "photoresist" are used interchangeably. EUV radiation emitted by EUV radiation source 102 is guided by optical elements to project the mask pattern onto the photoresist layer of the substrate. In some embodiments, the mask is reflective.

[0024] In various embodiments, the semiconductor substrate is a semiconductor wafer, such as a silicon wafer or other type of wafer to be patterned. The semiconductor substrate is coated with a resist layer sensitive to EUV radiation. Various components, including those described above, are integrated and operable to perform a lithography process. According to various embodiments, the EUV lithography system 100 may further include or be integrated (or coupled) with other modules.

[0025] like Figure 1 As shown, the EUV radiation source 102 includes a droplet generator 115 and a laser-generated plasma collection mirror 110, enclosed by a chamber 105. The droplet generator 115 generates a plurality of target droplets DP, which are supplied to the chamber 105 through a nozzle 117. In some embodiments, the target droplets DP are Sn, Li, or an alloy of Sn and Li. In some embodiments, each target droplet DP has a diameter ranging from about 10 micrometers to about 102 micrometers.

[0026] The excitation laser beam LR2 generated by the excitation laser source 300 is a pulsed beam. The laser pulses of the laser beam LR2 are generated by the excitation laser source 300. The excitation laser source 300 includes a laser generator 310, a laser guiding optics system 320, and a focusing device 330. In some embodiments, the laser generator 310 includes a carbon dioxide (CO2) or neodymium-doped yttrium aluminum garnet (Nd:YAG) laser source with wavelengths in the infrared region of the electromagnetic spectrum. For example, in one embodiment, the laser source 310 has a wavelength of 9.4 micrometers or 10.6 micrometers. The laser beam LR0 generated by the excitation laser source 300 is guided by the laser guiding optics system 320 and focused by the focusing device 330 into the excitation laser beam LR2 introduced into the EUV radiation source 102. In some embodiments, in addition to CO2 and Nd:YAG lasers, the laser beam LR2 is generated by: a gas laser, including an excimer gas discharge laser, a helium-neon laser, a nitrogen laser, a transversely excited atmospheric (TEA) laser, an argon ion laser, a copper vapor laser, a KrF laser, or an ArF laser; or a solid-state laser, including an Nd:glass laser, a ytterbium-doped glass or ceramic laser, or a ruby ​​laser. In some embodiments, a non-ionizing laser beam (not shown) is also generated by the excitation laser source 300, and the non-ionizing laser beam is also focused by the focusing device 330.

[0027] The laser beam LR2 is guided to the excitation region ZE through a window or lens (not shown). The window or lens may be made of a suitable material that is substantially transparent to the laser beam. The generation of the laser pulse is synchronized with the ejection of the target droplet DP through nozzle 117. As the target droplet moves through the excitation region, the pre-pulse heats the target droplet and transforms it into a low-density target plume. The delay between the pre-pulse and the main pulse is controlled to allow the target plume to form and expand to an optimal size and geometry. In various embodiments, the pre-pulse and the main pulse have the same pulse duration and peak power. When the main pulse heats the target plume, a high-temperature plasma is generated. The plasma emits EUV radiation, which is collected by a collection mirror 110. The collection mirror 110, configured as an EUV collection mirror, further reflects and focuses the EUV radiation, which may be provided to the exposure apparatus 202. Droplets DP that do not interact with the laser pulse are captured by a droplet trap 85.

[0028] Figure 2 This is a vertical cross-sectional view of an electron beam detection system 402 according to various embodiments. The electron beam detection system 402 is configured as an electron multi-beam detection system. The electron beam detection system 402 includes an electron source 404 (e.g., an "electron gun") configured to generate a main electron beam 406. The electron beam detection system 402 further includes a beam splitter 408 configured to generate sub-beams 410 from the main electron beam 406. As shown, the sub-beams 410 are guided to a semiconductor device 34 (e.g., a wafer having circuit elements formed therein).

[0029] Electron beam detection system 402 further includes focusing device 412 configured to focus main electron beam 406 onto an optimized sub-region of beam splitter 408. As described in more detail below (e.g., see reference 402). Figures 3A to 4C By focusing the main electron beam 406 onto the optimized sub-region of the beam splitter 408 (i.e., a region smaller than the total area of ​​the beam splitter 408), the electron beam current is increased and system performance is improved, thereby reducing the number of sub-beams 410 that would otherwise be directed to the featureless region of the semiconductor device 34. According to various embodiments, the electron beam detection system 402 further includes a mask (300b, 500) having a blocking region 508 and an opening region 510 (see...). Figure 3B , Figure 5A and Figure 5B As described in more detail below, the blocking region 508 is configured to block a first portion of the plurality of sub-bundles 410, and the opening region 510 is configured to allow a second portion of the plurality of sub-bundles 410 to pass through the hood (300b, 500).

[0030] In some embodiments, the electron beam inspection system 402 is coupled to the extreme ultraviolet (EUV) lithography system 100; however, in other embodiments, the electron beam inspection system 402 may operate as a stand-alone unit at various stages of the semiconductor manufacturing process line. According to various embodiments, different approaches are used when coupled to the EUV lithography system 100, depending on the specific design and requirements of the semiconductor manufacturing line. For example, in some embodiments, the electron beam inspection system 402 is not mounted in the same vacuum chamber as the EUV patterning module, but rather in a separate inspection module. However, in these embodiments, the process is configured to ensure efficient wafer transfer between the EUV lithography tool 100 and the electron beam inspection system 402, whether maintaining vacuum or allowing controlled venting.

[0031] According to various embodiments, wafers are transferred from the EUV lithography apparatus 202 or another module in the process line to the electron beam inspection system 402 without disrupting the vacuum. This configuration is advantageous because it minimizes the risk of contamination, even small particles which can significantly impact yield due to the fine feature size of the patterned material. The vacuum-based wafer handling system ensures a contaminant-free environment during the transfer process. This can be achieved by integrating a vacuum-compatible robotic handling system (not shown) that transfers wafers between the EUV lithography tool 100 or other modules in the process line and the electron beam inspection system 402 via vacuum-tight loadlocks.

[0032] Alternatively, in some embodiments, the wafer is transferred to the multibeam inspection system 402 via a controlled venting process, where the vacuum is temporarily disrupted but under highly controlled conditions to prevent contamination. In this case, the chamber is purged with clean gas, and the time spent outside the vacuum is minimized to reduce the possibility of particulate or chemical contamination. The decision of whether to maintain a vacuum or allow controlled venting during wafer transfer depends on the specific design goals of the semiconductor manufacturing line, the importance of contamination control, and throughput considerations. Maintaining a vacuum throughout the process may be implemented in high-end manufacturing environments because it enhances cleanliness and reduces the likelihood of yield loss due to defects introduced during processing. However, both configurations can be successfully implemented, and the multibeam inspection system 402 is integrated as an important tool for defect detection at various stages of semiconductor device manufacturing operations.

[0033] like Figure 2 As shown, when the electron beam (i.e., sub-beam 410) interacts with the material of the semiconductor device 34, signals 413 such as secondary electrons, backscattered electrons, or X-rays are generated (see, for example, see...). Figure 2These signals are collected and analyzed by detector 414 to identify features or irregularities on semiconductor device 34. Compared to single-beam systems, multi-beam methods can improve inspection speed and throughput while maintaining the ability to achieve detailed, high-resolution imaging. Electron beam inspection system 402 is configured to support automated defect detection and classification, making it suitable for high-volume semiconductor manufacturing processes. This system can adapt to inspecting complex structures and geometries, which is advantageous as semiconductor technology nodes continue to advance and feature sizes continue to shrink.

[0034] Based on information provided by the electron beam inspection system 402, various corrective actions are implemented in different embodiments to address defects and optimize the semiconductor manufacturing process, ultimately improving yield and device quality. One step involves defect classification and root cause analysis, where detailed data on defect type, size, and location allows engineers to identify the source of problems such as contamination, poor lithography alignment, or process variations. In some embodiments, this leads to targeted corrective actions, such as process adjustments.

[0035] In this regard, this data can be used to optimize process parameters for future batches. For example, if consistent defects, such as linewidth variations, are detected, adjustments to extreme ultraviolet lithography system settings, such as exposure dose or mask alignment, may be necessary. Furthermore, insights from this system can drive yield improvement strategies by highlighting the tools or process steps that lead to defects, prompting actions such as more frequent mask cleaning or changes to process control protocols.

[0036] Using multiple beams (i.e., sub-beams 410) in an electron multi-beam inspection system (such as electron beam inspection system 402) offers several advantages for improving the efficiency and effectiveness of semiconductor manufacturing processes. One of the main reasons for employing multiple beams is increased throughput, as this approach enables the simultaneous inspection of larger areas of semiconductor device 34. By dividing the main electron beam 406 into multiple sub-beams 410, system 402 can cover a larger surface area in the same amount of time, which is particularly valuable in high-volume manufacturing environments compared to single-beam inspection, as rapid inspection is crucial for maintaining production efficiency. The parallel processing characteristics of multiple beams also facilitate more comprehensive data collection during inspection, enabling simultaneous imaging and analysis. This parallelism accelerates the inspection process and allows for more detailed and accurate evaluation of the wafer surface.

[0037] Furthermore, utilizing multibeams significantly reduces overall inspection time, which is crucial in semiconductor manufacturing as inspection delays can lead to production bottlenecks. Faster inspection provides quicker feedback to the manufacturing process, enabling timely adjustments to maintain quality control. Multibeams also offer flexibility in inspection techniques, allowing for the simultaneous use of various imaging modalities, such as high-resolution imaging, dark-field imaging, or defect classification. Overall, these advantages contribute to more efficient and effective semiconductor manufacturing processes, ultimately resulting in higher-quality products.

[0038] Electron beam inspection system 402 includes several components that work together to achieve high-resolution and high-efficiency inspection of semiconductor wafers. As described above, system 402 includes an electron source 404 that generates a stable, high-intensity main electron beam 406, which is split into multiple sub-beams 410 by a beam splitter 408. This beam splitter 408 works in conjunction with an optical system (e.g., including a focusing device 412). The optical system includes electromagnetic lenses and apertures that focus and control the paths of the individual beams, ensuring that each beam is correctly aligned and focused on the semiconductor device 34.

[0039] The scanning system uses electrostatic or electromagnetic deflectors to guide the beam across the semiconductor device 34, ensuring complete surface coverage during inspection. The semiconductor device 34 is situated on a movable stage 360 ​​capable of precise XY motion, which in some embodiments is electrically controlled by a feedback system to ensure accurate alignment throughout the process. Detectors 414, strategically positioned around the system 402, collect signals 413, such as secondary electrons or backscattered electrons, generated when the electron beam interacts with the semiconductor device 34. These signals 413 are processed to create high-resolution images revealing defects or surface irregularities.

[0040] System 402 also includes a data processing and control unit (not shown) for analyzing the collected signal 413 and coordinating the electron source 404, optical elements 412, scanning system, and stage 360 ​​to ensure precise and synchronized operation. To prevent electron beam scattering 410, detection is performed within a vacuum chamber (not shown), which provides an optimal controlled environment for beam stability and imaging resolution. Together, these components enable the system to efficiently inspect wafers (e.g., substrates (10, 210) and semiconductor devices 34), thereby meeting the stringent requirements of semiconductor manufacturing processes.

[0041] Focusing device 412, a component of the optical system, works in conjunction with beam splitter 408 and includes electromagnetic lenses, deflectors, and apertures. The electromagnetic lenses are used to focus individual electron beams onto a fine point on the surface of semiconductor device 34. These lenses generate magnetic fields that bend and shape the electron paths, allowing precise control over beam focusing and convergence. In addition to focusing the beams, the optical system also ensures that the beams maintain a consistent spacing and alignment on the wafer. Deflectors (not shown) within the system are responsible for guiding the beams along specific trajectories, enabling them to scan designated areas of the wafer in a controlled and coordinated manner.

[0042] The apertures and deflectors in the electron multi-beam inspection system 402 are crucial for segmenting and controlling the electron beams, ensuring precise scanning and inspection of the wafer surface. These elements are designed to manage the trajectory and focus of each beam as it passes through the system. According to some embodiments, microelectromechanical systems (MEMS) technology is employed to create highly accurate and controllable apertures and deflectors, achieving superior beam manipulation.

[0043] Apertures, acting as beam-shaping elements, selectively allow portions of the electron beam to pass through while blocking the rest. These apertures are arranged in a well-defined grid or array, dividing the main electron beam into multiple smaller beams. MEMS-based apertures are particularly effective because they are small, precisely manufactured, and maintain high positioning accuracy. These MEMS apertures can be fabricated using materials such as silicon, providing both structural integrity and efficient interaction with the electron beam.

[0044] Deflectors guide the path of individual beams, typically electrostatically or electromagnetically, using controlled electric or magnetic fields to manipulate the direction of electrons. MEMS-based deflectors utilize microscale actuators to precisely adjust the beam path. By adjusting the voltage or current applied to these MEMS deflectors, the system can dynamically change the beam's angle and position, ensuring accurate scanning of the wafer surface.

[0045] According to some embodiments, the focusing device 412 includes a variable condenser lens located between the electron source 404 and the beam splitter 408. In other embodiments, the focusing device 412 also includes a non-variable condenser lens (not shown) located between the electron source 404 and the variable condenser lens 412. The variable condenser lens 412 is an adjustable optical element for electron beam systems, including electron multi-beam detection systems, for controlling and focusing an electron beam onto a target surface, such as a semiconductor wafer. The function of the condenser lens is to shape and converge the electron beam into a small, focused point, ensuring that the beam maintains the required intensity and resolution during detection or imaging.

[0046] The term "variable" refers to the lens's ability to dynamically adjust its focal characteristics, allowing the operator to modify the electron beam characteristics in real time. In some embodiments, this adjustability is achieved by changing the intensity of the electromagnetic field generated by the lens. The variable converging lens 412 uses electromagnetic coils to generate the magnetic field through which the electron beam passes. By controlling the current applied to these coils, the magnetic field strength is altered, thereby affecting the lens's focusing ability. Increasing the current strengthens the field and tightens the focus, while decreasing the current widens the focus.

[0047] One of the advantages of the variable converging lens 412 is its ability to adapt to different operational requirements. For example, during low-magnification imaging, the lens can be adjusted to focus the beam over a larger area, allowing for faster scanning and coverage. For high-resolution imaging, the lens can be adjusted to provide tighter focusing, enabling the system to capture detailed features on the wafer with greater accuracy. This flexibility is particularly beneficial in semiconductor device inspection, as different stages of the manufacturing process may require varying levels of resolution and accuracy.

[0048] Figure 3A This is a top view of a beam splitter 300a configured as an aperture array, according to various embodiments. In this embodiment, the beam splitter 300a is an aperture array including a plurality of reconfigurable apertures 502. According to various embodiments, the beam splitter 300a includes a plurality of MEMS actuators (not shown) configured to dynamically and individually control the plurality of apertures 502. The aperture array is configured to form blocking regions by a plurality of closed apertures 502 and opening regions by a plurality of open apertures 502. A region of interest 504 defines a semiconductor device circuit feature to be detected, which is superimposed on the aperture array (i.e., showing the relative positions of the circuit feature and the beam splitter 300a). Figure 3A The lower part schematically shows the scan path 506 of a single sub-beam 410. As shown, the area of ​​the region of interest 504 is significantly smaller than the total area of ​​the beam splitter 300a. Therefore, the sub-beam 410 passing through the opening 502, which does not overlap with the region of interest 504, tends to generate signals unrelated to the features of the circuit being scanned.

[0049] Figure 3B This is a top view of a mask 300b having a blocking region 508 and an opening region 510, according to various embodiments. The mask 300b includes a blocking region 508 configured to block a first plurality of sub-beams 410, and an opening region 510 configured to allow a second plurality of sub-beams 410 to pass through the mask 300b. As shown, the opening region 510 has a shape corresponding to a region of interest 504 on a wafer (e.g., semiconductor device 34) located below the mask 300b. The mask 300b is used to improve the throughput of the electron beam detection system 402 by removing otherwise irrelevant sub-beams 410 (i.e., sub-beams not pointing towards the region of interest 504). In this respect, unwanted signals 413 are reduced by blocking the first plurality of sub-beams 410 that are irrelevant to the feature being detected (i.e., features corresponding to the shape of the region of interest 504).

[0050] Therefore, by considering only the signal 413 generated by the second plurality of sub-beams 410 that allow passage through the opening region 510 of the mask 300b, the throughput is increased. However, the electron beam current in the second plurality of sub-beams 410 that allow passage through the opening region 510 of the mask 300b is less than the current if the main electron beam 406 could be more tightly focused, as described below. Figures 4A to 4C More detailed description.

[0051] Figures 4A to 4C This is a top view of beam splitters (400a, 400b, 400c) with focused electron beam impact optimized beam irradiation areas (602a, 602b, 602c), according to various embodiments. As shown in the figure, in Figures 4A to 4C In each of these, the optimized beam irradiation regions (602a, 602b, 602c) are smaller than (e.g., see arrows) the total area of ​​their respective beam splitters (400a, 400b, 400c). As described above, the focusing device 412 (e.g., a variable converging lens) generates the optimized beam irradiation regions (602a, 602b, 602c) from the main electron beam 406. Also as shown, in each case, the selected optimized beam irradiation regions (602a, 602b, 602c) have an area closely surrounding the region of interest 504. Therefore, only the opening 502 within the optimized beam irradiation regions (602a, 602b, 602c) (e.g., see arrows) Figure 3A This will generate sub-beams 410. Therefore, sub-beams 410 outside the optimized beam irradiation region (602a, 602b, 602c) will not be generated. In this way, each sub-beam 410 generated within the optimized beam irradiation region (602a, 602b, 602c) has a larger beam current than the sub-beams generated when the main electron beam 406 is not so closely focused.

[0052] According to various embodiments, the electron beam detection system 402 combines the mask 300b with a main electron beam 406 that focuses to form optimized beam irradiation regions (602a, 602b, 602c). In this way, productivity is improved by increasing the electron current in the sub-beams 410 generated by the focused electron beam having optimized beam irradiation regions (602a, 602b, 602c). Furthermore, the mask 300b is configured such that the opening region 510 of the mask is located within the optimized sub-region of the beam splitter (i.e., the sub-region corresponding to the optimized beam irradiation regions (602a, 602b, 602c)). Various types of mask 300b are used in the respective embodiments. For example, in some embodiments, the mask 300b has a fixed configuration with a fixed blocking region 508 and a fixed opening region 510. In other embodiments, the mask 300b is configured based on a reconfigurable shutter system, wherein the blocking region 508 and the opening region 510 are reconfigurable, as referred to below. Figure 5A and Figure 5B More detailed description.

[0053] Figure 5A and Figure 5B The first configuration is a canopy 500 with a reconfigurable partition system. Figure 5A ) and second configuration ( Figure 5B The top view in the image is shown according to various embodiments. According to various embodiments, the canopy 500 includes a plurality of reconfigurable partitions 702 (e.g., microelectromechanical system shutters), configured to dynamically control the size and shape of the blocking region 508 and the opening region 510. Figure 5A As shown, the reconfigurable partition 702 allows for the definition of various shapes for the blocking region 508 and the opening region 510. For example, as Figure 5B As shown, multiple reconfigurable partitions 702 open to define an opening region 510 having a shape corresponding to the region of interest 504.

[0054] Figure 6 This is a vertical cross-sectional view of an electron beam detection system 600 including a reconfigurable multiple masking device 802 with multiple selectable masks (300b, 500), according to various embodiments. The reconfigurable multiple masking device 802 includes a positioning device 804 configured to position a selected mask 500 between a beam splitter (408, 300a, 400a, 400b, 400c) and a semiconductor device 34. In this regard, the semiconductor device 34 is supported by a stage 360 ​​(e.g., see...). Figure 2 The platform 360 supports the positioning of the semiconductor device 34 relative to the positioning device 804. The reconfigurable multi-mask device 802 allows dynamic selection of various masks (300b, 500) based on the various circuit patterns to be detected on the semiconductor device 34. Figure 6 In one embodiment, the positioning device 804 is configured as a rotatable stage to move the selected mask (300b, 500) into place by rotation. However, the disclosed embodiments are not limited thereto, and various other configurations of the positioning device 804 are implemented in other embodiments. According to various embodiments, the electron beam detection system 402 described above is integrated with the lithography system 100, as described in more detail below. In other embodiments, the electron beam detection system 402 is separate from and distinct from the lithography system 100.

[0055] Referring to all the drawings and various embodiments of the present disclosure, an electron beam detection system 402 is provided. The electron beam detection system 402 includes an electron source 404, a focusing device 412, a focused main electron beam 406 configured to generate a focused main electron beam having an optimized beam irradiation area (602a, 602b, 602c), a beam splitter 408 having an area larger than the optimized beam irradiation area (602a, 602b, 602c), and a reconfigurable multiple masking device 802 including a plurality of selective masks 500.

[0056] According to various embodiments, the electron beam detection system 402 further includes a mask (300b, 500) having a blocking region 508 and an opening region 510. According to various embodiments, the opening region 510 is located within an optimized beam irradiation region (602a, 602b, 602c). According to various embodiments, the mask 500 includes a plurality of microelectromechanical partitions 702 configured to dynamically control the size and shape of the blocking region 508 and the opening region 510. According to various embodiments, the opening region 510 of the mask (300b, 500) has a shape corresponding to a region of interest 504 of the circuit pattern on the substrate (10, 210). According to various embodiments, the mask (300b, 500) is one of a plurality of selectable masks (300b, 500) in a reconfigurable multiple mask device 802. According to various embodiments, the electron beam detection system 402 also includes a positioning device 804 configured to position a selected mask (300b, 500) between the beam splitter 408 and the substrate holder 360.

[0057] Figure 7 This is a flowchart illustrating the operation of a semiconductor substrate (10, 210) electron multi-beam detection method 700 according to various embodiments. In operation 702, method 700 includes generating a main electron beam 406. In operation 704, method 700 includes focusing the main electron beam 406 to generate a focused electron beam 406 including an optimized beam irradiation region (602a, 602b, 602c). In operation 706, method 700 includes generating sub-beams 410 from the focused electron beam 406 by striking beam splitters (408, 300a, 400a, 400b, 400c) such that the optimized beam irradiation region (602a, 602b, 602c) is smaller than the total area of ​​the beam splitters (408, 300a, 400a, 400b, 400c).

[0058] In operation 708, method 700 includes blocking a first plurality of sub-beams 410 by impinging them against a mask (300b, 500) including a blocking region 508 and an opening region 510, such that the first plurality of sub-beams are blocked while a second plurality of sub-beams pass through the mask, wherein the opening region 510 is located within an optimized beam irradiation region (602a, 602b, 602c). According to various embodiments, the mask (300b, 500) includes a plurality of microelectromechanical separators 702. Method 700 also includes dynamically controlling the size and shape of the blocking region 508 and the opening region 510 by controlling the plurality of microelectromechanical separators 702 such that the opening region 510 of the mask (300b, 500) corresponds to a region of interest 504 of the circuit pattern on the semiconductor substrate (10, 210).

[0059] According to various embodiments, the mask (300b, 500) is one of a plurality of selectable masks (300b, 500) of the reconfigurable multiple mask device 802. In these embodiments, method 700 further includes a positioning device 804 controlling the reconfigurable multiple mask device 802 to select a mask (300b, 500) from the plurality of selectable masks (300b, 500) and position the mask (300b, 500) between the beam splitter (408, 300a, 400a, 400b, 400c) and the substrate support 360.

[0060] The disclosed embodiments offer advantages in improving signal quality and throughput by providing a system (100, 402) and method 700 for performing multi-beam electron detection on semiconductor substrates (10, 210). In this regard, method 700 includes focusing a main electron beam 406 to generate a focused electron beam 406 having optimized beam irradiation regions (602a, 602b, 602c). The focused electron beam 406 is then struck by beam splitters (300a, 400a, 400b, 400c) such that the optimized beam irradiation regions (602a, 602b, 602c) are smaller than the total area of ​​the beam splitters (300a, 400a, 400b, 400c). Therefore, the electron sub-beams 410 generated by the beam splitters (300a, 400a, 400b, 400c) are directed only to regions closely surrounding the region of interest 504 corresponding to the circuit element to be scanned. By focusing and optimizing the electron beam 406 in this way, the electron current in the individual sub-beams 410 is increased. The masks (300b, 500) are also used to block sub-beams 410 from regions outside the region of interest 504. This blocking reduces unwanted signals from regions outside the region of interest 504, thereby increasing the throughput of the electron multi-beam detection system 402.

[0061] According to various embodiments, an electron beam detection system includes an electron source configured to generate a main electron beam, a beam splitter configured to generate sub-beams from the main electron beam, a focusing device configured to focus the main electron beam onto an optimized sub-region of the beam splitter, wherein the optimized sub-region is smaller than the total area of ​​the beam splitter, and a mask including a first plurality of blocking regions configured to block the sub-beams and a second plurality of opening regions configured to allow the sub-beams to pass through the mask. According to various embodiments, the focusing device includes a variable converging lens located between the electron source and the beam splitter. According to various embodiments, the focusing device further includes a non-variable converging lens located between the electron source and the variable converging lens.

[0062] According to various embodiments, the beam splitter is an array of openings including a plurality of openings, such that a blocking region includes a closed opening, while an opening region includes an open opening. According to various embodiments, the beam splitter includes a plurality of microelectromechanical (MEMS) spacers configured for dynamic control. According to various embodiments, the opening regions of the mask are located within an optimized sub-region of the beam splitter. According to various embodiments, the opening regions of the mask have a shape corresponding to a region of interest on a wafer below the mask. According to various embodiments, the mask includes fixed blocking regions and fixed opening regions.

[0063] According to various embodiments, the electron beam detection system further includes a reconfigurable multi-mask device with multiple selectable masks, and the mask is one of multiple selectable masks in the reconfigurable multi-mask device. According to various embodiments, the mask includes a reconfigurable partition system, wherein the blocking region and the opening region are reconfigurable. According to various embodiments, the reconfigurable partition system includes multiple microelectromechanical (MEMS) partitions configured to dynamically control the size and shape of the blocking region and the opening region. In other embodiments, the partitions do not need to be MEMS partitions, but are configured as mechanical elements manufactured by other methods.

[0064] According to various embodiments, an electron beam detection system includes an electron source, a focusing device configured to generate a main electron beam including an optimized beam irradiation region, a beam splitter having an area larger than the optimized beam irradiation region, and a reconfigurable multiple masking device comprising a plurality of selectable masks. According to various embodiments, the electron beam detection system further includes a mask having a blocking region and an opening region, wherein the opening region is located within the optimized beam irradiation region. According to various embodiments, the mask includes a plurality of microelectromechanical (MEMS) spacers configured to dynamically control the size and shape of the blocking region and the opening region. According to various embodiments, the opening region of the mask has a shape corresponding to a region of interest in a substrate circuit pattern. According to various embodiments, the mask is one of a plurality of selectable masks in the reconfigurable multiple masking device. According to various embodiments, the electron beam detection system further includes a positioning device configured to position a selected mask between the beam splitter and a substrate support.

[0065] According to various embodiments, a method for performing multi-beam electron detection on a semiconductor substrate includes generating a main electron beam; focusing the main electron beam to generate a focused electron beam including an optimized beam irradiation region; generating sub-beams from the focused electron beam by impinging the focused electron beam on a beam splitter, such that the optimized beam irradiation region is smaller than the total area of ​​the beam splitter; and blocking a first plurality of sub-beams by impinging the sub-beams on a mask including a blocking region and an opening region, such that a second plurality of sub-beams pass through the mask, wherein the opening region is located within the optimized beam irradiation region.

[0066] According to various embodiments, the mask includes a plurality of microelectromechanical (MEMS) spacers, and the method further includes dynamically controlling the size and shape of the blocking region and the opening region by controlling the plurality of MEMS spacers, such that the opening region of the mask corresponds to the region of interest of the semiconductor substrate circuit pattern. According to various embodiments, the mask is one of a plurality of selectable masks in a reconfigurable multiple mask device, and the method further includes controlling the positioning device of the reconfigurable multiple mask device to select the mask from the plurality of selectable masks and position the mask between the beam splitter and the substrate support.

[0067] The foregoing has outlined features of several embodiments to enable those skilled in the art to better understand the nature of this disclosure. Those skilled in the art should understand that they can readily use this disclosure as a basis for designing or modifying other processes and structures to achieve the same purposes and / or attain the same advantages as the embodiments described herein. Those skilled in the art should also recognize that such equivalent constructions do not depart from the spirit and scope of this disclosure, and that they can make various changes, substitutions, and modifications thereto without departing from the spirit and scope of this disclosure.

Claims

1. An electron beam detection system, characterized by, include: An electron source is configured to generate a main electron beam; A beam splitter is configured to generate sub-beams from the main electron beam; A focusing device is configured to focus the main electron beam onto an optimized sub-region of the beam splitter, wherein the optimized sub-region is smaller than the total area of ​​the beam splitter. as well as The shroud includes a blocking region and an opening region, the blocking region being configured to block a first plurality of said sub-beams, and the opening region being configured to allow a second plurality of said sub-beams to pass through the shroud.

2. The electron beam detection system of claim 1, wherein, The focusing device includes a variable converging lens located between the electron source and the beam splitter.

3. The electron beam detection system of claim 1, wherein, The beam splitter is an array of openings, including multiple openings, such that the blocking region includes closed openings and the opening region includes open openings.

4. The electron beam detection system of claim 1, wherein, The canopy includes a reconfigurable partition system in which the blocking area and the opening area are reconfigurable.

5. An electron beam detection system characterized by, include: Electronic source; A focusing device, configured to generate a main electron beam including an optimized beam irradiation region; The beam splitter has an area larger than the optimized beam illumination region; as well as A reconfigurable multi-mask device, comprising multiple selectable masks.

6. The electron beam detection system of claim 5, wherein, Further includes: The shroud includes a blocking area and an opening area, wherein the opening area is located within the optimized beam irradiation area.

7. The electron beam detection system of claim 6, wherein, The canopy includes multiple microelectromechanical partitions, which are configured to dynamically control the size and shape of the blocking area and the opening area.

8. The electron beam detection system of claim 6, wherein, The opening region of the cover has a shape corresponding to the region of interest of the circuit pattern on the substrate.

9. The electron beam detection system of claim 6, wherein, The shroud is one of the multiple selectable shrouds of the reconfigurable multiple shroud device.

10. The electron beam detection system of claim 9, wherein, Further includes: The positioning device is configured to position the selected mask between the beam splitter and the substrate support.

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