Time-division multiplexed wafer z tilt-height sensor for charged particle beam focusing

Abstract

A method of measuring tilt and height characteristics in a charged particle system is disclosed. Time division multiplexing can be employed to use one module to separate in time measurements of tilt and height characteristics of a sample. A first light beam can be reflected from the sample to measure the tilt characteristics, and a second light beam can be reflected from the sample to measure the height characteristics. The first light beam can be triggered by an electrical signal associated with a falling edge of a clock signal, and the second light beam can be triggered by an electrical signal associated with a rising edge of the clock signal.

Description

Cross Reference to Related Applications

[0001] This application claims priority to U.S. Application 63 / 625,774, filed January 26, 2024, which is incorporated herein by reference in its entirety. Technical Field

[0002] This article describes the field of charged particle systems, and more particularly the measurement of the tilt and height characteristics of samples in charged particle systems. Background Technology

[0003] A photolithography apparatus is a machine that applies a desired pattern to a target portion of a substrate. For example, photolithography apparatuses can be used to manufacture integrated circuits (ICs). The IC chip in a smartphone can be as small as a human thumbnail and can contain over 2 billion transistors. Manufacturing ICs is a complex and time-consuming process, with circuit components located in different layers and involving hundreds of individual steps. Even an error in a single step can lead to problems with the final IC and potentially cause device failure. Therefore, in the IC manufacturing process, both completed and unfinished circuit components are inspected to ensure they are manufactured according to the design and free of defects. Inspection systems utilizing optical microscopes or charged particle (e.g., electron) beam microscopes (such as scanning electron microscopy (SEM)) can be employed. As the physical dimensions of IC components continue to shrink, the accuracy and yield of IC inspection become increasingly important. The presence of defects can impact high process yields and high wafer throughput, especially when physical testing is required to address defects during inspection. Therefore, accurate inspection and measurement are necessary to ensure the correct manufacture of defect-free ICs. Summary of the Invention

[0004] The embodiments provided herein disclose a method for monitoring and evaluating wafer fabrication process variations using the characteristics of extracted two-dimensional measurement data of features fabricated on a wafer.

[0005] Some embodiments of this disclosure provide a charged particle beam system. The charged particle beam system includes: a charged particle beam tool having circuitry configured to emit and focus a charged particle beam at a first location on the surface of a sample; an emitter module having circuitry configured to emit a first beam and a second beam to reflect from a second location on the sample surface, wherein the emitter module emits the first beam upon receiving a first signal and emits the second beam upon receiving a second signal; a detector module having circuitry configured to collect the first beam to measure a first characteristic of the sample and collect the second beam to measure a second characteristic of the sample; and a controller communicatively connected to the emitter module and the detector module, wherein the controller is configured to determine the first and second signals from input signals and supply the first and second signals to the emitter module.

[0006] In some embodiments, a non-transitory computer-readable medium includes an instruction set executable by one or more processors of a computing device to cause the computing device to perform operations for measuring sample properties in a charged particle beam apparatus. The operations include emitting a light beam from a light source using a first lens to deliver the beam to a surface of a sample, wherein the beam is reflected from the sample surface; focusing the beam reflected from the sample surface onto a detector surface using a second lens to generate a first measurement; and using the first measurement to determine the properties of the sample.

[0007] Other advantages of this disclosure will become apparent from the following description taken in conjunction with the accompanying drawings, in which certain embodiments of the disclosure are illustrated and exemplified. Attached Figure Description

[0008] The above and other aspects of this disclosure will become more apparent from the description of exemplary embodiments in conjunction with the accompanying drawings.

[0009] Figure 1 This is a schematic diagram illustrating an example photolithography projection assembly for fabricating an IC, consistent with embodiments of the present disclosure.

[0010] Figure 2 This is a schematic diagram illustrating an example electron beam inspection (EBI) system consistent with embodiments of the present disclosure.

[0011] Figure 3 This is a schematic diagram illustrating an example multi-beam tool consistent with embodiments of the present disclosure.

[0012] Figure 4A , 4B Figures 4C and 4C are example illustrations of the effects of uncorrected tilt characteristics in conventional charged particle beam systems.

[0013] Figure 5A This is an example charged particle beam system consistent with embodiments of this disclosure.

[0014] Figure 5B This is an example charged particle beam system consistent with embodiments of this disclosure.

[0015] Figure 5C This is an example charged particle beam system consistent with embodiments of this disclosure.

[0016] Figure 5D and 5E This is an illustration of an example first lens and a second lens configured to deliver a light beam to a detector, consistent with embodiments of this disclosure.

[0017] Figure 6 This is an example illustration of a detector that can be used to monitor a beam of light reflected from a sample, consistent with embodiments of this disclosure.

[0018] Figure 7A , 7B Figures 7 and 7C are illustrations of example input signals used by a controller to calculate a first signal and a second signal, consistent with embodiments of this disclosure.

[0019] Figure 8A and 8B This is an illustration of an example charged particle beam system consistent with embodiments of this disclosure.

[0020] Figure 9A This is an illustration of measuring sample characteristics using a light beam, consistent with embodiments of this disclosure.

[0021] Figure 9B , 9C Figures 9D, 9E, 9F, 9G, 9H, 9I, and 9J illustrate first and second characteristics of a measurement sample consistent with embodiments of the present disclosure.

[0022] Figure 10 This is a flowchart illustrating an exemplary process consistent with embodiments of the present disclosure.

[0023] Figure 11 This is a flowchart illustrating an exemplary process consistent with embodiments of the present disclosure. Detailed Implementation

[0024] Exemplary embodiments will now be described in detail, examples of which are illustrated in the accompanying drawings. The following description refers to the accompanying drawings, wherein, unless otherwise indicated, the same numerals in different drawings denote the same or similar elements. The implementations set forth in the following description of the exemplary embodiments do not represent all implementations consistent with the invention. Rather, they are merely examples of apparatuses and methods consistent with various aspects of the invention as enumerated in the appended claims. For example, although some embodiments are described in the context of the use of electron beams, this disclosure is not limited thereto. Other types of charged particle beams can be applied similarly. Furthermore, other imaging systems can be used, such as optical imaging, photoelectric detection, X-ray detection, etc.

[0025] The increased computing power of electronic devices can be achieved by significantly increasing the packaging density of circuit components (such as transistors, capacitors, diodes, etc.) on IC chips, while simultaneously reducing the physical size of the device. For example, the IC chip in a smartphone (about the size of a thumbnail) can include over 2 billion transistors, each less than 1 / 1000th the size of a human hair. Therefore, it's not surprising that semiconductor IC manufacturing is a complex and time-consuming process with hundreds of individual steps. Even an error in one step can drastically affect the operation of the final product. Even a "fatal defect" can cause equipment failure. The goal of a manufacturing process is to increase the overall yield of the process. For example, to achieve a 75% yield in a 50-step process, the yield of each individual step must be greater than 99.4%, and if the yield of each step is only 95%, the overall process yield drops to 7%.

[0026] While high process yields are required in IC chip manufacturing facilities, maintaining high wafer throughput (defined as the number of wafers processed per hour) is also essential. The presence of defects can impact both high process yields and high wafer throughput, especially when defect inspection requires operator intervention. Furthermore, the number of transistors fabricated on IC chips is projected to increase from billions to trillions by 2030. Therefore, high-throughput detection and identification of micron- and nanometer-scale defects using inspection tools such as charged particle beam inspection tools is crucial for maintaining high yields and low costs. Inspecting wafers using electron beam inspection tools generates images of the wafer to measure IC structure dimensions. These measured dimensions can be compared to a reference structure without defects to determine the presence of defects in the imaged structure. However, inspecting ICs for defect detection is typically a time-consuming process. It may be desirable to prevent defects during the fabrication phase rather than further refining IC inspection methods. Therefore, it is desirable to monitor and evaluate photolithography fabrication conditions that could cause defects in the fabricated IC structure.

[0027] ICs can be manufactured using photolithography, a fabrication process involving the creation of complex circuit patterns drawn on a mask deposited on a substrate. Photolithography can be performed using a photolithography apparatus, a machine that applies a radiation source (such as light or X-rays) to a target portion of a substrate to form the desired pattern. The target portion of the substrate can be covered with a patterning device (such as a mask), which can be removed or developed after exposure to the radiation source. This process of transferring the desired pattern onto the substrate is called a patterning process. A patterning process may include patterning steps to transfer a pattern from a patterning device (such as a mask) to the substrate. There may also be one or more associated patterning steps, such as mask development using a developing apparatus, baking the substrate using a baking tool, etching the pattern onto the substrate using an etching apparatus, or other chemical and physical processing steps involved in creating a pattern on the substrate. Variations in experimental parameters (such as random variations, errors, or noise due to inspection tools or patterning tools) can potentially limit the photolithography implementation or process yield of high-volume manufacturing (HVM) of ICs and introduce defects into the IC structure.

[0028] When manufacturing ICs using photolithography equipment, numerous photolithographic patterning steps are typically performed to form functional features in successive layers on a substrate. Therefore, a key aspect of the performance of the photolithography equipment is its ability to correctly and accurately place the applied pattern with respect to features laid in previous layers. For this purpose, the substrate is provided with one or more sets of alignment marks. Each mark is a structure whose position can be measured later using tools such as electron beam inspection. Defects can occur if the applied patterned structure or patterned layer is not correctly positioned with respect to the reference marks, or if fabrication conditions are suboptimal. Reference marks or layouts define the desired structure, structure dimensions, and distances between IC structures (such as gates, capacitors, etc.) or interconnects. This ensures that IC devices or lines do not interact with each other in undesirable ways. The structural constraints provided by the reference layout are often referred to as critical dimensions. A critical dimension of a circuit can be defined as the minimum width of a line or via, or the minimum space between two lines or two vias. Therefore, critical dimensions determine the overall size and package density of the designed IC. The goal of IC fabrication is to faithfully reproduce the original IC design on the substrate. If an error occurs during manufacturing, resulting in an IC design pattern that does not match the reference design, this can lead to defects in the IC structure and render the IC inoperable.

[0029] As mentioned above, high throughput is required for IC fabrication with low structural defect rates. Additionally, the number of transistors fabricated on a wafer is projected to reach one trillion by 2030. As the fabrication process for these transistors becomes more complex and involves more steps, this could increase process variations and introduce more defects. Furthermore, scaling up semiconductor production can introduce random variations in the photolithography process. Randomness and process variations can introduce structural defects into the manufactured wafers, such as dopant concentration fluctuations, pattern line edge roughness, edge placement errors, and variations between structures intended for the same purpose, which could ultimately render the wafer unusable. Therefore, there is a need to accurately inspect the fabricated IC structure and collect metrological measurements for comparison with the desired design and fabrication conditions in photolithography. Current systems and methods rely on height sensors to monitor the height of the sample under inspection in real time and maintain the focused charged particle beam on the sample. Accurate height measurement is crucial so that the charged particle beam can be correctly focused onto the sample surface. However, since conventional height sensors only measure the relative distance between the sample and the top of the charged particle beam chamber, they cannot be used to monitor sample tilt or localized changes in sample height. Furthermore, uncorrected sample tilt can obstruct the path of the charged particle beam, degrade image quality, and hinder efficient sample inspection and measurement. Additionally, temperature variations during stage movement can cause sample deformation, potentially exacerbating sample tilt. Conventional systems currently rely on adjusting the charged particle beam trajectory to compensate for sample tilt, but this can introduce uncontrollable aberrations or distortions in image quality and further reduce inspection and measurement throughput. Therefore, during high-volume manufacturing (HVM), using current methods and charged particle beam systems to compensate for sample tilt can lead to measurement inaccuracies, undesirable reductions in sample and image quality, and decreased wafer yield.

[0030] Embodiments of this disclosure provide a method for monitoring and measuring the tilt characteristics of a sample using a light beam. Some embodiments of this disclosure may provide a method for separately measuring tilt characteristics using different light beams and height characteristics. The light beams may be visible light and may each have different wavelengths. This disclosure also provides a time-division multiplexed charged particle beam system configuration for efficiently and accurately measuring the local tilt and height characteristics of a sample. In some embodiments, this disclosure provides a charged particle beam system to integrate a tilt sensor and a height sensor into a single module. Real-time and point-of-interest measurements of local sample tilt and sample height can be achieved. Moreover, some embodiments of this disclosure can improve the throughput of IC manufacturing and the confidence level of inspection and measurement.

[0031] For clarity, the relative dimensions of components in the accompanying drawings may be exaggerated. Throughout the following description of the drawings, the same or similar reference numerals refer to the same or similar components or entities, and only differences relative to the various embodiments are described. As used herein, unless specifically stated otherwise, the term "or" covers all possible combinations except those that are impractical. For example, if a database may include A or B, then unless specifically stated otherwise or impractical, the database may include A or B or A and B. As a second example, if a database may include A, B, or C, then unless specifically stated otherwise or impractical, the database may include A or B or C or A and B or A and C or B and C or A and B and C.

[0032] Now refer to Figure 1 This is a schematic diagram illustrating an exemplary photolithography projection apparatus 100. The photolithography projection apparatus 100 may include an emission source 101, which may be a charged particle emission source, a deep ultraviolet excimer laser source, or other type of source including an extreme ultraviolet (EUV) source, and an emission beam 108. Irradiation optics may include: irradiation optics components 102 and 103 that shape the radiation from the radiation source 101; a pattern forming apparatus 104; and a transmission optics 105 that projects an image of a pattern from the pattern forming apparatus onto a substrate 106. An adjustable filter or aperture 107 at the pupil plane of the projection optics may limit the range of beam angles striking the substrate 106, wherein the maximum possible angle defines the numerical aperture NA of the projection optics as NA = sin( The location where the beam 108 impacts the substrate 106 is referred to as the target portion 109, where the beam impacts the top layer or mask (not shown).

[0033] Irradiation optics components 102 and 103 can guide and shape the beam 108 onto the substrate 106 via patterning apparatus 104, and may include any optical components capable of altering the wavefront of the beam 108. A resist layer on the substrate 106 can be exposed, and the radiation intensity distribution (i.e., spatial image) at the substrate 106 can be transferred to the resist layer. The optical properties of the photolithography projection apparatus (e.g., the properties of the source, patterning apparatus, and projection optics) specify this process. The resist layer can be removed, and then the applied pattern from the beam 108 can be applied to the substrate as discussed above.

[0034] Although reference may be made to ICs in this disclosure, it is to be understood that this disclosure is applicable to other possible applications or designs. For example, this disclosure can be applied to integrated optical systems, magnetic domain memories, liquid crystal display panels, thin-film magnetic heads, and other nanoscale structures. It should be further understood that the terms “mask,” “wafer,” or “die” are used interchangeably with the terms “mask,” “substrate,” or “sample,” and “target portion,” respectively.

[0035] Figure 2 An example electron beam inspection (EBI) system 200 consistent with embodiments of this disclosure is illustrated. The EBI system 200 can be used for imaging. Figure 2 As shown, the EBI system 200 includes a main chamber 201, a loading / locking chamber 202, a beam tool 204, and an Equipment Front End Module (EFEM) 206. The beam tool 204 is located within the main chamber 201. The EFEM 206 includes a first loading port 206a and a second loading port 206b. The EFEM 206 may include multiple additional loading ports. The first loading port 206a and the second loading port 206b receive wafer front-opening transfer cassettes (FOUPs) containing wafers to be inspected (e.g., semiconductor wafers or wafers made of (multiple) other materials) or samples (wafers and samples are interchangeable). A "batch" is a plurality of wafers that can be loaded and processed as a batch.

[0036] One or more robotic arms (not shown) in EFEM 206 can transport the wafer to loading / locking chamber 202. Loading / locking chamber 202 is connected to a loading / locking vacuum pump system (not shown), which removes gas molecules from loading / locking chamber 202 to achieve a first pressure below atmospheric pressure. After reaching the first pressure, one or more robotic arms (not shown) can transport the wafer from loading / locking chamber 202 to main chamber 201. Main chamber 201 is connected to a main chamber vacuum pump system (not shown), which removes gas molecules from main chamber 201 to achieve a second pressure below the first pressure. After reaching the second pressure, the wafer is inspected by a beam tool 204. Beam tool 204 can be a single-beam system or a multi-beam system.

[0037] Controller 209 is electronically connected to beam tool 204. Controller 209 may be a computer configured to perform various controls of EBI system 200. Although in Figure 2 The controller 209 is shown outside the structure including the main chamber 201, the loading / locking chamber 202 and the EFEM 206, but it should be understood that the controller 209 may be part of the structure.

[0038] In some embodiments, controller 209 may include one or more processors (not shown). A processor may be a general-purpose or specific electronic device capable of manipulating or processing information. For example, a processor may include any number of central processing units (or “CPU”), graphics processing units (or “GPU”), optical processors, programmable logic controllers, microcontrollers, microprocessors, digital signal processors, intellectual property (IP) cores, programmable logic arrays (PLAs), programmable array logic (PALs), general-purpose array logic (GALs), complex programmable logic devices (CPLDs), field-programmable gate arrays (FPGAs), system-on-a-chip (SoCs), application-specific integrated circuits (ASICs), neural processing units (NPUs), and any combination of any type of circuitry capable of data processing. A processor may also be a virtual processor, comprising one or more processors distributed across multiple machines or devices coupled via a network.

[0039] In some embodiments, controller 209 may also include one or more memories (not shown). The memory can be a general-purpose or specific electronic device capable of storing processor-accessible (e.g., via a bus) code and data. For example, the memory can include any number of random access memory (RAM), read-only memory (ROM), optical disc, magnetic disk, hard disk, solid-state drive, flash drive, secure digital (SD) card, memory stick, compact flash (CF) card, or any combination of any type of storage device. The code and data can include an operating system (OS) and one or more applications (or “applications”) for a specific task. The memory can also be virtual memory, which includes one or more memories distributed across multiple machines or devices coupled via a network.

[0040] Figure 3 The illustration shows an example multi-beam tool 204 (also referred to herein as apparatus 204) and an image processing system 390 consistent with embodiments of the present disclosure, which can be configured for use in EBI system 200 ( Figure 2 ).

[0041] The beam tool 204 includes a charged particle source 302, a gun aperture 304, a converging lens 306, a primary charged particle beam 310 emitted from the charged particle source 302, a source conversion unit 312, multiple beams 314, 316, and 318 of the primary charged particle beam 310, a primary projection optics system 320, a motorized wafer stage 380, a wafer holder 382, ​​multiple secondary charged particle beams 336, 338, and 340, a secondary optics system 342, and a charged particle detection device 344. The primary projection optics system 322 may include a beam splitter 322, a deflection scanning unit 326, and an objective lens 328. The charged particle detection device 344 may include detection sub-regions 346, 348, and 350.

[0042] The charged particle source 302, the gun aperture 304, the converging lens 306, the source conversion unit 312, the beam splitter 322, the deflection scanning unit 326, and the objective lens 328 can be aligned with the primary optical axis 360 of the device 204. The secondary optical system 342 and the charged particle detection device 344 can be aligned with the secondary optical axis 352 of the device 204.

[0043] Charged particle source 302 can emit one or more charged particles, such as electrons, protons, ions, muons, or any other charged particles. In some embodiments, charged particle source 302 can be an electron source. For example, charged particle source 302 can include a cathode, extractor, or anode, wherein primary electrons can be emitted from the cathode and extracted or accelerated to form a primary charged particle beam 310 (in this case, a primary electron beam) with a cross (virtual or real) 308. For ease of explanation and without ambiguity, electrons are used as examples in some descriptions herein. However, it should be noted that any charged particle can be used in any embodiment of this disclosure, not limited to electrons. The primary charged particle beam 310 can be visualized as being emitted from the cross 308. The aperture 304 can block peripheral charged particles of the primary charged particle beam 310 to reduce the Coulomb effect. The Coulomb effect can cause an increase in the size of the probe spot.

[0044] The source conversion unit 312 may include an image forming element array and a beam-limiting aperture array. The image forming element array may include an array of micro-deflectors or microlenses. The image forming element array can form multiple parallel images (virtual or real) at an intersection 308 with multiple beam waves 314, 316, and 318 of the primary charged particle beam 310. The beam-limiting aperture array can limit the multiple beam waves 314, 316, and 318. Although in Figure 3 Three beams 314, 316, and 318 are shown, but embodiments of this disclosure are not limited thereto. For example, in some embodiments, device 204 may be configured to generate a first number of beams. In some embodiments, the first number of beams may be in the range of 1 to 1000. In some embodiments, the first number of beams may be in the range of 200 to 500. In an exemplary embodiment, device 204 may generate 400 beams.

[0045] The converging lens 306 can focus the primary charged particle beam 310. The currents of the beams 314, 316, and 318 downstream of the source conversion unit 312 can be changed by adjusting the focusing capability of the converging lens 306 or by changing the radial dimensions of the corresponding beam-limiting apertures within the beam-limiting aperture array. The objective lens 328 can focus the beams 314, 316, and 318 onto the wafer 330 for imaging, and can form multiple probe spots 370, 372, and 374 on the surface of the wafer 330.

[0046] Beam splitter 322 can be a Wien filter type beam splitter that generates electrostatic dipole fields and magnetic dipole fields. In some embodiments, if they are applied, the force exerted by the electrostatic dipole field on the charged particles (e.g., electrons) of beam waves 314, 316, and 318 on the charged particles can be substantially equal in amplitude and opposite in direction to the force exerted by the magnetic dipole field on the charged particles. Therefore, beam waves 314, 316, and 318 can pass directly through beam splitter 322 with zero deflection angle. However, the total dispersion of beam waves 314, 316, and 318 generated by beam splitter 322 can also be non-zero. Beam splitter 322 can separate secondary charged particle beams 336, 338, and 340 from beam waves 314, 316, and 318 and guide secondary charged particle beams 336, 338, and 340 toward secondary optical system 342.

[0047] The deflection scanning unit 326 can deflect beams 314, 316, and 318 to scan probe spots 370, 372, and 374 on the surface region of wafer 330. In response to the incident beams 314, 316, and 318 at probe spots 370, 372, and 374, secondary charged particle beams 336, 338, and 340 can be emitted from wafer 330. The secondary charged particle beams 336, 338, and 340 can include charged particles (electrons) with an energy distribution. For example, the secondary charged particle beams 336, 338, and 340 can be a secondary electron beam comprising secondary electrons (energy ≤ 50 eV) and backscattered electrons (energy between 50 eV and the landing energy of beams 314, 316, and 318). The secondary optical system 342 can focus secondary charged particle beams 336, 338, and 340 onto detection sub-regions 346, 348, and 350 of the charged particle detection device 344. Detection sub-regions 346, 348, and 350 can be configured to detect the corresponding secondary charged particle beams 336, 338, and 340 and generate corresponding signals (e.g., voltage, current, etc.) for reconstructing SCPM images of structures on or beneath the surface region of the wafer 330.

[0048] The generated signals can represent the intensity of the secondary charged particle beams 336, 338, and 340, and can be provided to an image processing system 390 that communicates with the charged particle detection device 344, the primary projection optics system 320, and the motorized wafer stage 380. The movement speed of the motorized wafer stage 380 can be synchronized and coordinated with the beam deflection controlled by the deflection scanning unit 326, so that the movement of the scanning probe spots (e.g., scanning probe spots 370, 372, and 374) can orderly cover the region of interest on the wafer 330. The parameters of this synchronization and coordination can be adjusted to accommodate different materials of the wafer 330. For example, different materials of the wafer 330 may have different resistivity-capacitance characteristics, which may result in different signal sensitivities to the movement of the scanning probe spots.

[0049] The intensities of the secondary charged particle beams 336, 338, and 340 can vary depending on the external or internal structure of the wafer 330, thus indicating whether the wafer 330 contains defects. Furthermore, as discussed above, beams 314, 316, and 318 can be projected onto different locations on the top surface of the wafer 330 or different sides of a local structure of the wafer 330 to generate secondary charged particle beams 336, 338, and 340 with varying intensities. Therefore, by mapping the intensities of the secondary charged particle beams 336, 338, and 340 to regions of the wafer 330, the image processing system 390 can reconstruct an image reflecting the characteristics of the internal or external structure of the wafer 330.

[0050] In some embodiments, the image processing system 390 (which may be part of the controller 209) may include an image acquirer 392, a storage device 394, and a controller 396. The image acquirer 392 may include one or more processors. For example, the image acquirer 392 may include a computer, server, mainframe, terminal, personal computer, any kind of mobile computing device, or a combination thereof. The image acquirer 392 may be communicatively coupled to the charged particle detection device 344 of the beam tool 204 via a medium such as an electrical conductor, fiber optic cable, portable storage medium, IR, Bluetooth, the Internet, wireless network, radio, or a combination thereof. In some embodiments, the image acquirer 392 may receive signals from the charged particle detection device 344 and may construct an image. The image acquirer 392 may thus acquire an SCPM image of the wafer 330. The image acquirer 392 may also perform various post-processing functions, such as generating contours, overlaying indicators on the acquired image, etc. The image acquirer 392 may be configured to perform adjustments to the brightness and contrast of the acquired image. In some embodiments, storage device 394 may be a storage medium such as a hard disk, flash drive, cloud storage device, random access memory (RAM), or other types of computer-readable storage. Storage device 394 may be coupled to image acquirer 392 and may be used to store scanned original image data as the original image and post-processed images. Image acquirer 392 and storage device 394 may be connected to controller 396. In some embodiments, image acquirer 392, storage device 394, and controller 396 may be integrated into a single control unit.

[0051] In some embodiments, the image acquisition unit 392 may acquire one or more SCPM images of the wafer based on imaging signals received from the charged particle detection device 344. The imaging signals may correspond to a scanning operation for performing charged particle imaging. The acquired image may be a single image comprising multiple imaging regions. The single image may be stored in the storage device 394. The single image may be an initial image that can be divided into multiple regions. Each region may include an imaging region containing features of the wafer 330. The acquired images may include multiple images of a single imaging region of the wafer 330 sampled multiple times over a time series. The multiple images may be stored in the storage device 394. In some embodiments, the image processing system 390 may be configured to perform image processing steps on multiple images of the same location on the wafer 330.

[0052] In some embodiments, the image processing system 390 may include measurement circuitry (e.g., an analog-to-digital converter) to obtain the distribution of detected secondary charged particles (e.g., secondary electrons). Charged particle distribution data collected during the detection time window can be combined with corresponding scan path data of beams 314, 316, and 318 incident on the wafer surface to reconstruct an image of the inspected wafer structure. The reconstructed image can be used to reveal various features of the internal or external structure of the wafer 330, and thus can be used to reveal any defects that may exist in the wafer.

[0053] In some embodiments, the charged particles can be electrons. When electrons from the primary charged particle beam 310 are projected onto the surface of the wafer 330 (e.g., probe spots 370, 372, and 374), the electrons from the primary charged particle beam 310 can penetrate the surface of the wafer 330 to a certain depth and interact with the particles of the wafer 330. Some electrons from the primary charged particle beam 310 can elastically interact with the material of the wafer 330 (e.g., in the form of elastic scattering or collision) and can be reflected or bounced off the surface of the wafer 330. Elastic interaction conserves the total kinetic energy of the interacting subjects (e.g., electrons from the primary charged particle beam 310), where the kinetic energy of the interacting subjects is not converted into other forms of energy (e.g., heat, electromagnetic energy, etc.). Such reflected electrons generated by elastic interaction can be called backscattered electrons (BSE). Some electrons from the primary charged particle beam 310 can inelastically interact with the material of the wafer 330 (e.g., in the form of inelastic scattering or collision). Inelastic interaction does not conserve the total kinetic energy of the interacting subjects, where some or all of the kinetic energy of the interacting subjects is converted into other forms of energy. For example, through inelastic interactions, the kinetic energy of some electrons in the primary charged particle beam 310 may lead to electronic excitation and transitions between material atoms. This inelastic interaction can also generate electrons that leave the surface of the wafer 330; these electrons can be referred to as secondary electrons (SEs). The yield or emission rate of BSEs and SEs depends, for example, on the material being examined and the landing energy of the electrons from the primary charged particle beam 310 on the material surface. The energy of the electrons in the primary charged particle beam 310 can be partly determined by its accelerating voltage (e.g., ...). Figure 3 The accelerating voltage between the anode and cathode of the charged particle source 302 is imparted. The BSE and SE apples may have more or fewer (or even the same) injected electrons than the primary charged particle beam 310.

[0054] Images generated by SCPM can be used for defect inspection. For example, a generated image capturing a test equipment area of ​​a wafer can be compared with a reference image capturing the same test equipment area. The reference image can be predetermined (e.g., by simulation) and does not include known defects. If the difference between the generated image and the reference image exceeds a tolerance level, a potential defect can be identified. For another example, SCPM can scan multiple areas of a wafer, each including a test equipment area designed to be identical, and generate multiple images capturing these manufactured test equipment areas. These multiple images can be compared with each other. If the difference between the multiple images exceeds a tolerance level, a potential defect can be identified.

[0055] While reference may be made to ICs in this disclosure, it is to be understood that this disclosure is applicable to other possible applications or designs. For example, this disclosure can be applied to integrated optical systems, magnetic domain memories, liquid crystal display panels, thin-film magnetic heads, and other nanoscale structures. It should also be understood that the terms "die," "structure," and "IC structure" are used interchangeably in this disclosure.

[0056] Conventional charged particle beam systems do not offer configurations or methods for measuring the tilt characteristics of samples. Monitoring and obtaining real-time tilt information of samples can be important for ensuring accurate inspection and measurement of samples such as fabricated ICs. (See now for further details.) Figures 4A to 4C The illustration depicts the challenges associated with inaccurate measurement of sample tilt in conventional charged particle beam systems. Figure 4A The illustration shows a sample 401 on a sample holder 402. The sample 401 can exhibit variations in flatness or local height across its entire surface. For example, region 403 on the sample 401 can be illustrated as a localized area (e.g., a 2 mm × 2 mm area) to be inspected in a charged particle beam apparatus. The charged particle beam can be focused at a location within region 403. However, the relative height of the sample may exceed an acceptable threshold, thus skewing any inspection or measurement results obtained. Conventional systems lack the configuration or method to monitor the tilt characteristics of the sample 401 and may not be able to adjust the tilt of the sample 401 in real time to ensure that region 403 has the same relative height. Therefore, it may be difficult to obtain accurate inspection or measurement values ​​of the sample 401 within region 403. Figure 4B The illustration shows a charged particle beam 404 focused onto feature 405 on a first layer 406 of a sample. The sample includes a second layer 407 buried beneath the first layer 406, and the second layer 407 contains feature 408. During sample fabrication, the goal is to fabricate features 405 and 408 at the same locations on the first layer 406 and the second layer 407 (e.g., vertical alignment). An image 409 of the sample collected using the charged particle beam 404 can be used to obtain measurement overlay measurements 410. However,Figure 4B Assume the sample is not tilted during image collection. Figure 4C The illustration shows the same sample, but with a non-zero tilt characteristic that was not considered or monitored using conventional systems. Figure 4C As illustrated, the charged particle beam 404 does not penetrate deep enough into the sample to "capture" the image 411 of feature 408 in the second layer 407. Therefore, image 411 will not present measurement overlay measurements, potentially indicating false positives for defect-free structures and allowing defective wafers to be missed during wafer fabrication.

[0057] Now refer to Figure 5A The illustration depicts a charged particle beam system 500 consistent with embodiments of this disclosure. For example... Figure 5A As shown, the charged particle beam system 500 may include a charged particle beam device 501 (e.g., Figure 1 Photolithography projection device 100 Figure 2 204, the binding tool Figure 3 The multi-beam tool 204), the sample to be inspected 502, the transmitter module 503a, the detector module 503b, and the controller 504 (e.g., Figure 2 Controller 209 Figure 3The controller 396). The charged particle beam device 501 can emit a charged particle beam 505 and focus it onto a first position (not shown) on the sample 502. The emitter module 503a can include circuitry configured to emit a beam 506 to be reflected from the sample 502, and the detector module 503b can include circuitry configured to collect the beam 506 and measure characteristics of the sample 502. In some embodiments, the beam 506 can be a visible beam, an ultraviolet beam, or an infrared beam. In some embodiments, the beam 506 is a visible beam. In some embodiments, the beam 506 can be reflected from the sample 502 at the first position. In some embodiments, the beam 506 can be reflected from the sample 502 at a second position, wherein the second position is within a local region surrounding the first position. It should be understood that the phrase "within a local region" can be understood to mean a 2-mm × 2-mm region on the sample 502 surrounding the first position. In some embodiments, the second position can be within a 2-mm distance from the first position. The emitter module 503a can emit the beam 506 onto the sample 502 at an incident angle θ. The beam 506 can be collected by the detector module 503b and used to calculate the characteristics of the sample 502. In some embodiments, this characteristic is a tilt characteristic. In some embodiments, this characteristic is a height characteristic. The controller 504 can be communicatively connected to the transmitter module 503a and provides a signal to the transmitter module 503a to emit the beam 506. In some embodiments, the controller 504 can be communicatively connected to the detector module 503b. In some embodiments, the controller 504 can receive signals from the detector module 503b to calculate the characteristics of the sample 502. Although Figure 5A Not shown in the figure, but controller 504 can be communicatively connected to charged particle beam device 501.

[0058] Now refer to Figure 5B The illustration depicts a charged particle beam system 500 consistent with an embodiment of this disclosure. Figure 5B The illustration shows that emitter module 503a may include emitter component 507 and first lens 508, and detector module 503b may include second lens 509 and detector 510. Charged particle beam device 501 can emit charged particle beam 505 and focus it onto sample 502, as shown above. Figure 5A As described in [the text]. Controller 504 can be communicatively connected to transmitter component 507 and detector 510. In some embodiments, controller 504 can calculate a first signal and transmit the first signal to transmitter component 507. Transmitter component 507 can then emit beam 511 (e.g., [the text is incomplete]). Figure 5AA first lens 508 can transmit a beam 511 to the surface of a sample 502. The beam 511 can be reflected from the surface of the sample 502 and collected by a second lens 509. In some embodiments, the second lens 509 can focus the beam 511 onto a detector 510. The focused beam 511 can impact the surface of the detector 510, and the detector 510 can measure and generate an output signal. The detector 510 can output the output signal to a controller 504, and the controller 504 can use the output signal to calculate a first characteristic of the sample 502. In some embodiments, the controller 504 can calculate a second signal, pass the second signal to a transmitter component 507, and the transmitter component 507 can emit a second beam (not shown). The second beam can follow the same trajectory as the beam 511, and a second characteristic of the sample 502 can be calculated as described above. In some embodiments, the transmitter component 507 may include a first transmitter configured to emit the beam 511 (e.g., the first beam) in response to receiving the first signal. In some embodiments, the first transmitter may be a light source (e.g., a laser). In some embodiments, transmitter component 507 may include a second transmitter configured to emit a second beam in response to receiving a second signal. In some embodiments, the second transmitter may be a light source (e.g., a laser). In some embodiments, the first transmitter and the second transmitter may be the same transmitter and may be configured to emit beam 511 and the second beam separately.

[0059] In some embodiments, the first transmitter and the second transmitter may be separate and may be located in a separate transmitter component. Referring now to... Figure 5C The illustration depicts a charged particle beam system 512 consistent with an embodiment of this disclosure. Figure 5CThe illustration shows that emitter module 503a may include a first emitter 513, a second emitter 514, a beam member 515, and a first lens 508. Detector module 503b may include a second lens 509 and a detector 510. Charged particle beam device 501 may emit a charged particle beam 505 and focus it onto sample 502, as described above. Controller 504 may be communicatively connected to the first emitter 513, the second emitter 514, and the detector 510. In some embodiments, controller 504 may calculate a first signal and transmit the first signal to the first emitter 513. The first emitter 513 may then emit a first beam 516, which may pass through beam member 515. First lens 508 may deliver the first beam 516 to the surface of sample 502. The first beam 516 may be reflected from the surface of sample 502 and collected by second lens 509. In some embodiments, second lens 509 may focus the first beam 516 onto detector 510. A focused first beam 516 can impact the surface of detector 510, and detector 510 can measure and generate an output signal. Detector 510 can output the output signal to controller 504, and controller 504 can use the output signal to calculate a first characteristic of sample 502. In some embodiments, controller 504 can calculate a second signal, transmit the second signal to second emitter 514, and second emitter 514 can emit a second beam 517. The second beam 517 can be reflected from beam member 515 and transmitted to sample 502 via first lens 508. In some embodiments, beam member 515 is a mirror. In some embodiments, beam member 515 is a dichroic mirror. The second characteristic of sample 502 can be calculated as described above. In some embodiments, first emitter 513 can be a light source (e.g., a laser). In some embodiments, second emitter 514 can be a light source (e.g., a laser). In some embodiments, first beam 516 and second beam 517 can exhibit different wavelengths. In some embodiments, the wavelength of second beam 517 can be smaller than the wavelength of first beam 516. In some embodiments, the first characteristic of sample 502 is a tilt characteristic. In some embodiments, the second characteristic of sample 502 is a height characteristic. It should be understood that in some embodiments of this disclosure, the beam member 515 can be excluded, and therefore, as... Figure 5C The illustration optionally includes a beam member 515. In some embodiments, the first emitter 513 and the second emitter 514 may be positioned such that the first beam 516 and the second beam 517 can be emitted along parallel trajectories. In some embodiments, the first emitter 513 and the second emitter 514 may be positioned such that the first beam 516 and the second beam 517 can be emitted along intersecting trajectories.

[0060] Now refer to Figure 5D and 5EThese are schematic diagrams of example first and second lenses configured to deliver a light beam to a detector, consistent with embodiments of this disclosure. Figure 5D The illustration shows a first transmitter 513 emitting a first beam 516 (after receiving a first signal from a controller 504). The first beam 516 passes through a beam member 515 and is delivered to a sample 502 using a first lens 508. In some embodiments, the first lens 508 collimates the first beam 516, and the first beam remains collimated upon reflection from the sample 502. A second lens 509 receives the collimated first beam 516 and focuses it onto a detector 510. Figure 5E The illustration shows a second transmitter 514 emitting a second beam 517 (after receiving a second signal from a controller 504). The second beam 517 is reflected from a beam member 515 and delivered to a sample 502 using a first lens 508. In some embodiments, the first lens 508 focuses the second beam 517. The focused second beam 517 is reflected from the sample 502 and received by a second lens 509. The second lens 509 focuses the second beam 517 onto a detector 510. In some embodiments, the first lens 508 and the second lens 509 are configured to adjust the convergence, divergence, and parallelism of the first beam 516 and the second beam 517. In some embodiments, the first lens 508 and the second lens 509 are designed to adapt to a specific wavelength of the beam. In some embodiments, the first lens 508 and the second lens 509 may be designed to optimize the focal power difference between the first beam 516 and the second beam 517. In some embodiments, the first lens 508 may separate the collimated first beam 516 and the focused second beam 517 by applying a chromatic power difference. In some embodiments, the second lens 509 can focus the first beam 516 and the second beam 517 by applying a chromatic power difference.

[0061] Now refer to Figure 6 This illustrates a top view of the surface of a detector, consistent with embodiments of the present disclosure, that can be used to monitor a light beam reflected from a sample. In some embodiments, detector 610 may include multiple detection segments configured to measure the intensity of a light beam impacting a detection segment. For example, detector 610 may include four quadrants 610-1, 610-2, 610-3, 610-4, as... Figure 6 As shown. In some embodiments, detector 610 can be pixelated to measure the beam (e.g. Figure 5C , 5D The first beam 516 and Figure 5C , 5E The parameter fluctuations of the second beam 517). In some embodiments, the detector 610 can measure the relative positional displacement of the beam of the impact detector 610 to determine the characteristics of the sample from which the beam is reflected. For example, as Figure 6As shown, beam 620 may exhibit off-axis displacement when it impacts detector 610. Detector 610 itself or in conjunction with a controller (e.g., Figure 2 Controller 209 Figure 3 Controller 396 Figures 5A to 5C The controller 504 can calculate the off-axis displacement by measuring the impact intensity of each portion of the beam 620 in each quadrant of the detector 610 (620-1 in 610-1, 620-2 in 610-2, 620-3 in 610-3, and 620-4 in 610-4). For example, as Figure 6 As shown, quadrant 610-1 is impacted by the largest portion 620-1 of beam 620, thus producing the largest impact intensity output. In contrast, quadrant 610-3 is impacted by the smallest portion 620-3 of beam 620, thus producing the lowest impact intensity output. The measured intensity signals from quadrants 610-1, 610-2, 610-3, and 610-4 ( , , and The displacement of beam 620 in the X-plane 630 and in the Y-plane 640 can be transmitted to a controller, whereby the displacement of beam 620 in the X-plane 630 and in the Y-plane 640 can be calculated. It is understood that the X-plane displacement 630 and the Y-plane displacement 640 can be attributed to parameters of the sample. As an example, the displacement of the sample in the X-plane 630 can be calculated by determining the ratio of the intensity of beam 620 on the positive X-axis of detector 610 to the total intensity of the detected beam 620. Therefore, the characteristics of the sample can be calculated as follows: 630, And 640, . Detector 610 can collect measurement parameters or characteristics from beam 620 and transmit them to controller (e.g., Figure 2 Controller 209 Figure 3 Controller 396 Figures 5A to 5C Controller 504).

[0062] Now refer to Figures 7A to 7C This is a schematic diagram of an example input signal for a controller to calculate a first signal and a second signal, consistent with embodiments of the present disclosure. Figure 7A The diagram illustrates the controller (e.g.) Figure 2 Controller 209 Figure 3 Controller 396 Figures 5A to 5C The input signal of the controller 504 may have an input value 702 and a time component 701. In some embodiments, the input signal is a clock signal. Figure 7AThe illustration depicts a clock signal varying from a lower value 704 to a higher value 705. In some embodiments, the clock signal may include a rising edge 706, where the lower value 704 switches to the higher value 705. In some embodiments, the clock signal may include a falling edge 707, where the higher value 705 switches to the lower value 704. In some embodiments, the controller may detect the rising edge 706 and the falling edge 707, and separate the rising edge 706 from the falling edge 707. Figure 7B The diagram illustrates rising edge detection 708 over time 701, where the controller can be configured to identify whether a rising edge event 709 has occurred in the clock signal (e.g., rising edge detection value is 1). Figure 7C The illustration shows a falling edge detection 710 over time 701, where a controller can be configured to identify whether a falling edge event 711 (e.g., a falling edge detection value of 1) has occurred in a clock signal. If a rising edge event 709 occurs, the controller can calculate a first signal associated with the rising edge event 709. In some embodiments, the first signal can be the value of an electrical signal (e.g., voltage or current). If a falling edge event 711 occurs, the controller can calculate a second signal associated with the falling edge event 711. In some embodiments, the second signal can be the value of an electrical signal (e.g., voltage or current). In some embodiments, the first signal can be associated with a rising edge (e.g., rising edge event 709), and the second signal can be associated with a falling edge (e.g., falling edge event 711). In some embodiments, the first signal can be associated with a falling edge, and the second signal can be associated with a rising edge. It is understood that more than one clock signal can be used as an input signal to the controller. It is understood that any time between a rising edge (e.g., rising edge 706) and a falling edge (e.g., falling edge 707) can be set as an input to the controller in the clock signal. Embodiments of this disclosure are not limited to... Figures 7A to 7C The diagram illustrates, and may include any number of clock signals, rising edge events, and falling edge events.

[0063] In some embodiments, this disclosure provides a charged particle beam system configured to facilitate separate measurements of the tilt and height characteristics of a sample. Referring now... Figure 8A and 8B The illustration depicts a charged particle beam system, consistent with embodiments of the present disclosure, capable of separating a first measurement from a second measurement of a sample. Figure 8AThe diagram illustrates a charged particle beam system 800, which includes a transmitter module 803a, a detector module 803b, a controller 804, a sample 802, and a charged particle beam device (not shown). The transmitter module 803a includes a first transmitter 813, a second transmitter 814, a beam assembly 815, and a first lens 808. The detector module 803b includes a second lens 809 and a detector 810. In some embodiments, the controller 804 may be configured to calculate a first signal from an input signal (e.g., as shown above). Figures 7A to 7C As described in [the document], and provides a first signal to a first transmitter 813 and a detector 810. Upon receiving the first signal, the first transmitter 813 may emit a first beam 816 to measure a first characteristic of the sample 802. In some embodiments, the input signal may be a clock signal. In some embodiments, the first signal may be associated with the falling edge of the clock signal or with the rising edge of the clock signal. In some embodiments, the first signal is associated with the falling edge of the clock signal. The first beam 816 is collimated by a first lens 808 and reflected from the sample 802. A second lens 809 may receive the first beam 816 and focus it onto the detector 810, where measurements of the first characteristic of the sample 802 may be collected. In some embodiments, the measured value may be a ratio, where the ratio is the ratio of the intensity values ​​of the first beam 816 across one or more segments of the detector 810. In some embodiments, the detector 810 may output the measured value (e.g., an output signal) to a controller 804 to calculate the first characteristic of the sample 802. In some embodiments, the first characteristic is a tilt characteristic of the sample 802.

[0064] Figure 8B The illustration depicts a charged particle beam 800 configured to emit a second beam 817 to measure a second property of a sample, consistent with embodiments of this disclosure. In some embodiments, such as Figure 8A As described, a second beam 817 can be emitted after or before collecting measurements of the first characteristic. In some embodiments, the controller 804 can be configured to calculate a second signal from the input signal (e.g., as described above). Figures 7A to 7CAs described in [the description], and provides a second signal to a second transmitter 814 and a detector 810. Upon receiving the second signal, the second transmitter 814 can emit a second beam 817 to measure a second characteristic of the sample 802. In some embodiments, the input signal can be a clock signal. In some embodiments, the second signal can be associated with the falling edge of the clock signal or with the rising edge of the clock signal. In some embodiments, the second signal is associated with the rising edge of the clock signal. The second beam 817 is focused by a first lens 808 and reflected from the sample 802. A second lens 809 can receive the second beam 817 and focus it onto the detector 810, where measurements of the second characteristic of the sample 802 can be collected. In some embodiments, the measured value can be a ratio, where the ratio is the ratio of the intensity values ​​of the second beam 817 across one or more segments of the detector 810. In some embodiments, the detector 810 can output the measured value (e.g., an output signal) to a controller 804 to calculate the second characteristic of the sample 802. In some embodiments, the second characteristic is the height characteristic of the sample 802.

[0065] Figure 8A and 8B The illustration shows a time separation of a first and a second measurement of a sample according to an embodiment of the present disclosure.

[0066] Now refer to Figure 9A The illustration shows the use of a light beam to measure the characteristics of a sample according to an embodiment of the present disclosure. Figure 9A The illustration shows a transmitter 901 configured to emit a beam 902 (e.g., Figure 8A and 8B A first beam 816 or a second beam 817 is emitted from the sample 903 and measured by a detector 904. The detector 904 may include one or more segments configured to measure the reflected emission beam 902 to measure the characteristics of the sample 903.

[0067] Now refer to Figures 9B to 9J The illustration shows how the emission beam 902, consistent with an embodiment of the present disclosure, can be reflected from the sample 903 and measured according to different characteristics of the sample 903. Figures 9B to 9D Related to the tilting characteristics of sample 903, which can tilt (e.g., rotate) about the X-axis, a top view of the emitted beam 902 impacting the detector 904 is illustrated. Figure 9B As illustrated, sample 903 does not exhibit any tilt around the X-axis. The reflected emission beam 902 may impact the center of detector 904-B. (As shown...) Figure 9C As illustrated, sample 903 exhibits a clockwise tilt around the X-axis. The reflected emission beam 902 may impact the right side of detector 904-C.Figure 9D The illustration shows sample 903 tilted counterclockwise around the X-axis. Therefore, the reflected emission beam 902 may impact the left side of detector 904-D. Figures 9B to 9D Only the tilt around the X-axis is shown in the diagram; therefore, the impacted reflected beam could be depicted as being located on the horizontal axis of detectors 904-B, 904-C, and 904-D. It is important to understand that... Figures 9B to 9D The dashed arrows in the illustration are interpreted as "inside the page plane," while the thick arrows are "outside the page." Figures 9E to 9G Related to the tilting characteristics of sample 903, which can be tilted (e.g., rotated) about the Y-axis, a top view of the emitted beam 902 impacting the detector 904 is illustrated. Figure 9E As illustrated, sample 903 does not exhibit any tilt around the Y-axis. The reflected emission beam 902 may impact the center of detector 904-E. (As shown...) Figure 9F As illustrated, sample 903 exhibits a clockwise tilt around the Y-axis. The reflected emission beam 902 may impact the lower half of detector 904-F. Figure 9G The illustration shows sample 903 tilted counterclockwise around the Y-axis. Therefore, the reflected emission beam 902 may impact the upper half of detector 904-G. Figures 9E to 9G Only the tilt of sample 903 about the Y-axis is illustrated; therefore, the impacted reflected beam may be illustrated as being on the vertical axis of detectors 904-E, 904-F, and 904-G. It should be understood that sample 903 may exhibit tilts about both the X and Y axes. In some embodiments, the reflected emission beam 902 may impact detector 904 within one quadrant (e.g., not on the horizontal or vertical axis illustrated in detectors 904-B through 904-G).

[0068] Figures 9H to 9J Related to the height characteristics of sample 903, which can be shifted up or down on the Z-axis. Figures 9H to 9J The diagram relates to the height characteristics of sample 903 and illustrates a top view of the impact of the emission beam 902 on the detector 904 depending on whether the height characteristics of sample 903 change. Figure 9H The illustration shows that sample 903 did not exhibit any change in height. The reflected emission beam 902 may impact the center of detector 904-H. Figure 9I The illustration shows that the height of sample 903 is lower than the expected height. The dashed outline of sample 903 illustrates the expected height of sample 903, and the bold outline of sample 903-I illustrates the actual height of sample 903. The reflected emission beam 902 may impact the lower half of detector 904-I on the vertical axis. Figure 9JThe illustration shows that the height of sample 903-J is higher than the expected height value. The emitted beam 902 reflects from sample 903-J at the actual height and may impact the upper half of detector 904-J on the vertical axis. It should be understood that embodiments of this disclosure can provide no crosstalk between measurements of a first and a second characteristic of the sample. For example, a measurement of a tilt characteristic (e.g., tilt about the Y-axis) can be separated from a measurement of the height characteristic of the sample. Therefore, embodiments of this disclosure avoid measurement confusion and provide a system that clearly measures tilt characteristics in addition to the height characteristics of a sample in a charged particle beam apparatus.

[0069] Now refer to Figure 10 This is an example flowchart illustrating a method 1000 for measuring sample properties in a charged particle beam apparatus, consistent with embodiments of this disclosure. The steps of method 1000 can be performed by a computing device, which includes, for example... Figure 2 Controller 209 Figures 5A to 5D Controller 504 Figure 8A , 8B Controller 804 or Figure 3 Image processing system 390. It should be understood that the illustrated method 1000 can be modified to alter the order of steps and include additional steps.

[0070] In step 1001, a light beam from a light source is emitted using a first lens to deliver the beam to the surface of the sample, and the beam is reflected from the sample surface. The light beam can be a visible light beam. The light source can be a laser. In some embodiments, the light source can receive a signal from a controller to emit the beam. The signal from the controller can be an electrical signal associated with a clock signal. In some embodiments, the clock signal includes a rising edge and a falling edge. In some embodiments, the first lens can focus the beam such that the beam is focused upon delivery to the sample surface. In some embodiments, the first lens can collimate the beam. In some embodiments, the collimated beam can remain collimated after reflection from the sample surface.

[0071] In step 1002, a second lens is used to focus the reflected beam onto the surface of the detector to generate a first measurement. In some embodiments, the second lens focuses the reflected beam by applying a chromatic power difference. In some embodiments, the second lens is configured to optimize the power of the reflected beam. The surface of the detector includes one or more segments to monitor the characteristics of the reflected beam. In some embodiments, the detector includes quadrants. In some embodiments, the first measurement is a ratio. In some embodiments, the ratio is the ratio of the intensity values ​​of the beam from different segments of the impact detector. In some embodiments, the first measurement is an electrical signal.

[0072] In step 1003, a first measurement value is used to determine the characteristics of the sample. In some embodiments, the first measurement value is supplied to a controller performing the determination. In some embodiments, the characteristic of the sample is a tilt characteristic. In some embodiments, the characteristic of the sample is a height characteristic.

[0073] Now refer to Figure 11 This is an example flowchart illustrating a method 1100 for measuring a first characteristic and a second characteristic of a sample in a charged particle beam apparatus, consistent with embodiments of this disclosure. The steps of method 1100 can be performed by a computing device, which includes, for example... Figure 2 Controller 209 Figures 5A to 5D Controller 504 Figure 8A , 8B Controller 804 or Figure 3 Image processing system 390. It should be understood that the illustrated method 1100 can be modified to alter the order of steps and include additional steps.

[0074] In step 1101, a first transmitter emits a first beam of light. The first beam of light may be a visible beam of light. In some embodiments, the first transmitter is a light source. In some embodiments, the light source is a laser. The first transmitter may receive a signal from a controller to emit the first beam of light. The signal from the controller may be an electrical signal associated with a clock signal. In some embodiments, the clock signal includes a rising edge and a falling edge. In some embodiments, the signal from the controller may be the value of an electrical signal associated with the falling edge of the clock signal.

[0075] In step 1102, a first light beam is transmitted to the surface of the sample using a first lens, and the first light beam is reflected from the surface of the sample. In some embodiments, the first lens collimates the first light beam such that the first light beam is collimated when reflected from the sample surface.

[0076] In step 1103, a second lens is used to focus the first beam onto the surface of the detector to generate a first measurement. In some embodiments, the second lens focuses the first beam by applying a chromatic power difference. In some embodiments, the second lens is configured to optimize the power of the first beam. The surface of the detector includes one or more segments to monitor the characteristics of the first beam. In some embodiments, the detector includes quadrants. In some embodiments, the first measurement is a ratio. In some embodiments, the ratio is the ratio of the intensity values ​​of the first beam from different segments of the impact detector. In some embodiments, the first measurement is an electrical signal.

[0077] In step 1104, a second transmitter emits a second beam. The second beam may be a visible beam. In some embodiments, the second transmitter is a light source. In some embodiments, the light source is a laser. The second transmitter may receive a signal from a controller to emit the second beam. The signal from the controller may be an electrical signal associated with a clock signal. In some embodiments, the clock signal includes a rising edge and a falling edge. In some embodiments, the signal from the controller may be the value of an electrical signal associated with the rising edge of the clock signal. In some embodiments, the second beam has a wavelength smaller than that of the first beam.

[0078] In step 1105, a first lens is used to deliver a second beam to the surface of the sample, and the second beam is reflected from the surface of the sample. In some embodiments, the first lens may focus the second beam such that the second beam is focused when delivered to the sample surface.

[0079] In step 1106, a second beam is focused onto the surface of the detector using a second lens to generate a second measurement. In some embodiments, the second lens focuses the second beam by applying a chromatic power difference. In some embodiments, the second lens is configured to optimize the power of the second beam. The surface of the detector includes one or more segments to monitor the characteristics of the second beam. In some embodiments, the detector includes quadrants. In some embodiments, the second measurement is a ratio. In some embodiments, the ratio is the ratio of the intensity values ​​of the second beam from different segments of the impact detector. In some embodiments, the second measurement is an electrical signal.

[0080] In step 1107, a first measurement is used to determine a first characteristic of the sample, and a second measurement is used to determine a second measurement of the sample. In some embodiments, the controller determines the first characteristic and the second characteristic. In some embodiments, the first characteristic is the tilt characteristic of the sample, and the second characteristic is the height characteristic of the sample.

[0081] The benefits provided by embodiments of this disclosure can include methods for measuring the tilt characteristics of samples in a charged particle beam system. In some embodiments, more accurate information about the local tilt characteristics of a sample can be measured, and this can be used to avoid degradation of inspection image quality and measurement accuracy. In some embodiments, a method is disclosed for measuring tilt characteristics separately using different beams and height characteristics. The beams can be visible light and can each have different wavelengths. This disclosure also provides a time-division multiplexed charged particle beam system configuration for efficiently and accurately measuring the local tilt and height characteristics of a sample. In some embodiments, this disclosure provides a charged particle beam system that integrates a tilt sensor and a height sensor into a single module. Real-time and point-of-interest measurements of local sample tilt and sample height can be achieved. Moreover, some embodiments of this disclosure can improve the throughput of IC manufacturing and the confidence level of inspection and measurement.

[0082] A non-transitory computer-readable medium may be provided, which can store information for use in photolithography projection apparatuses (e.g., Figure 1 The processor of the photolithography projection device 100, and the inspection tool for collecting sample images (e.g., Figure 2 EBI system 200 or Figure 3 The processor of the multi-beam inspection tool 204 Figure 10 Method 1000 Figure 11 Method 1100 and instructions for other executable functions related to measuring sample characteristics, separately measuring the first and second characteristics of the sample, or measuring the tilt characteristics of the sample using a beam. Common forms of non-transient media include, for example, floppy disks, flexible disks, hard disks, solid-state drives, magnetic tape or any other magnetic data storage media, compact disc read-only memory (CD-ROM), any other optical data storage media, any physical media with a hole pattern, random access memory (ROM), programmable read-only memory (PROM) and erasable programmable read-only memory (EPROM), flash memory EPROM or any other flash memory, non-volatile random access memory (NVRAM), cache, registers, any other memory chips or cassette tapes and their networking versions.

[0083] The embodiments may be further described using the following terms: 1. A charged particle beam system, comprising: A charged particle beam tool having a circuit system configured to emit and focus a charged particle beam at a first position on the surface of a sample; The transmitter module has a circuit system configured to emit a first beam and a second beam to reflect from a second position on the surface of the sample, wherein the transmitter module emits the first beam after receiving a first signal and emits the second beam after receiving a second signal; A detector module having a circuit system configured to collect a first beam to measure a first characteristic of a sample and to collect a second beam to measure a second characteristic of a sample; and A controller is communicatively connected to a transmitter module and a detector module, wherein the controller is configured to determine a first signal and a second signal from an input signal and to supply the first signal and the second signal to the transmitter module. 2. A charged particle beam system according to Clause 1, wherein a first position on the surface of the sample is different from a second position. 3. A charged particle beam system according to Clause 1 or 2, wherein a second position on the surface of the sample is within a local region surrounding the first position. 4. A charged particle beam system according to Clause 3, wherein a second position on the surface of the sample is less than or equal to 2 mm from the first position. 5. A charged particle beam system according to any one of clauses 1 to 4, wherein the first beam has a wavelength different from that of the second beam. 6. A charged particle beam system according to any one of clauses 1 to 5, wherein the first beam is a visible beam. 7. A charged particle beam system according to any one of clauses 1 to 6, wherein the second beam is a visible beam. 8. A charged particle beam system according to any one of clauses 1 to 7, wherein the first characteristic of the sample is a tilt characteristic and the second characteristic is a height characteristic. 9. A charged particle beam system according to any one of clauses 5 to 8, wherein the second beam has a wavelength smaller than that of the first beam. 10. A charged particle beam system according to any one of clauses 1 to 9, wherein a first beam is collimated at a second position on the surface of a sample, and a second beam is focused at a second position on the surface of a sample. 11. A charged particle beam system according to any one of clauses 1 to 10, wherein the emitter module is configured to separate the emission of a first beam and a second beam. 12. A charged particle beam system according to any one of clauses 1 to 11, wherein the input signal is an electrical signal. 13. The charged particle beam system according to Clause 12, wherein Electrical signals include clock signals; The first signal includes an electrical signal associated with the first edge of the clock signal; and The second signal includes an electrical signal associated with the second edge of the clock signal. 14. A charged particle beam system according to any one of clauses 1 to 13, wherein the emitter module comprises: A first transmitter is configured to emit a first beam of light in response to receiving a first signal; The second transmitter is configured to emit a second beam in response to receiving a second signal; and The first lens is configured to deliver the first beam and the second beam to a second position on the sample. 15. A charged particle beam system according to Clause 14, wherein the first emitter is a light source. 16. A charged particle beam system pursuant to Clause 15, wherein the first emitter is a laser. 17. A charged particle beam system according to Clause 14 or 15, wherein the second emitter is a light source. 18. A charged particle beam system pursuant to Clause 17, wherein the second emitter is a laser. 19. A charged particle beam system according to any one of clauses 14 to 18, wherein a first lens is configured to collimate a first beam and focus a second beam. 20. A charged particle beam system according to any one of clauses 1 to 19, wherein the detector module comprises: Detector; and The second lens is configured to collect the first and second beams reflected from the sample and to transmit the first and second beams to the detector. 21. A charged particle beam system according to Clause 20, wherein a second lens is configured to focus a first beam and a second beam onto the surface of a detector. 22. A charged particle beam system according to clause 20 or 21, wherein a second lens is configured to apply a chromatic power difference to a first beam and a second beam to focus the first beam and the second beam onto a detector. 23. A charged particle beam system according to any one of clauses 20 to 22, wherein the detector comprises one or more segments for monitoring intensity changes of a first or second beam from an impact detector. 24. A charged particle beam system according to Clause 23, wherein the detector includes quadrants. 25. A charged particle beam system according to any one of clauses 20 to 24, wherein the detector outputs a third signal. 26. A charged particle beam system according to Clause 25, wherein a third signal provides information indicating the position of a first or second beam of an impact detector. 27. A charged particle beam system according to Clause 26, wherein a third signal provides information representing the ratio. 28. A charged particle beam system pursuant to Clause 27, wherein the ratio is a ratio of intensity values. 29. A charged particle beam system according to any one of clauses 26 to 28, wherein a third signal is used to calculate a first characteristic of the sample or a second characteristic of the sample. 30. A charged particle beam system according to any one of clauses 1 to 29, wherein the emitter module further includes a beam component. 31. A charged particle beam system according to Clause 30, wherein the beam component is configured to combine the first beam and the second beam before the first beam and the second beam are delivered to a second position on the sample surface. 32. A charged particle beam system according to clause 30 or 31, wherein the beam component is a mirror. 33. A charged particle beam system according to Clause 32, wherein a first beam passes through a mirror and a second beam is reflected from the mirror. 34. A charged particle beam system, comprising: A charged particle beam tool having a circuit system configured to emit and focus a charged particle beam at a first position on the surface of a sample; A first transmitter is configured to emit a first beam onto a second position on the sample surface in response to the first transmitter receiving a first signal; The second transmitter is configured to emit a second beam onto a second position on the sample surface in response to the second transmitter receiving a second signal; A detector is configured to receive a first light beam and a second light beam from a second location on the sample surface, wherein the detector measures a first characteristic of the sample from the first light beam and a second characteristic of the sample from the second light beam; and A controller has a circuit system configured to determine a first signal and a second signal from an input signal, wherein the controller is configured to switch between supplying a first signal to a first transmitter and supplying a second signal to a second transmitter. 35. A charged particle beam system according to Clause 34, wherein a first position on the surface of the sample is different from a second position. 36. A charged particle beam system according to clause 34 or 35, wherein a second position on the surface of the sample is in a local region surrounding a first position. 37. A charged particle beam system according to Clause 36, wherein a second position on the surface of the sample is less than or equal to a first position at a distance of 2 mm. 38. A charged particle beam system according to any one of clauses 34 to 37, wherein the first beam has a wavelength different from that of the second beam. 39. A charged particle beam system according to any one of clauses 34 to 38, wherein the first beam is a visible beam. 40. A charged particle beam system according to any one of clauses 34 to 39, wherein the second beam is a visible beam. 41. A charged particle beam system according to any one of clauses 34 to 40, wherein a first characteristic of the sample is an tilt characteristic and a second characteristic of the sample is a height characteristic. 42. A charged particle beam system according to any one of clauses 38 to 41, wherein the second beam has a wavelength smaller than that of the first beam. 43. A charged particle beam system according to any one of clauses 34 to 42, wherein the first beam is collimated when reflected from a second position on the surface of the sample, and the second beam is focused when reflected from a second position on the surface of the sample. 44. A charged particle beam system according to any one of clauses 34 to 43, wherein the first emitter is a light source. 45. A charged particle beam system according to any one of clauses 34 to 44, wherein the second emitter is a light source. 46. ​​A charged particle beam system according to Clause 44, wherein the first emitter is a laser. 47. A charged particle beam system pursuant to Clause 45, wherein the second emitter is a laser. 48. A charged particle beam system according to any one of clauses 34 to 47, wherein the input signal includes an electrical signal. 49. A charged particle beam system pursuant to Clause 48, wherein Electrical signals include clock signals; The first signal includes an electrical signal associated with the first edge of the clock signal; and The second signal includes an electrical signal associated with the second edge of the clock signal. 50. A charged particle beam system according to any one of clauses 24 to 49, wherein the detector includes one or more segments to monitor intensity changes measured from a first or second beam of the impact detector. 51. A charged particle beam system according to Clause 50, wherein the detector comprises quadrants. 52. A charged particle beam system according to any one of clauses 34 to 51, wherein the detector outputs a third signal. 53. A charged particle beam system according to Clause 52, wherein a third signal provides information indicating the position of a first or second beam of an impact detector. 54. A charged particle beam system according to clause 52 or 53, wherein a third signal provides information representing the ratio. 55. A charged particle beam system according to Clause 54, wherein the ratio is a ratio of intensity values. 56. A charged particle beam system according to any one of clauses 52 to 55, wherein a third signal is used to calculate a first characteristic of the sample or a second characteristic of the sample. 57. A charged particle beam system according to any one of clauses 34 to 56 further includes: A first lens is configured to deliver a first beam and a second beam to a second position on the sample; and The second lens is configured to collect the first beam and the second beam reflected from the second position of the sample, and to transmit the first beam and the second beam to the detector. 58. A charged particle beam system according to Clause 57, wherein a first lens is configured to collimate a first beam and focus a second beam. 59. A charged particle beam system according to clause 57 or 58, wherein a second lens is configured to focus a first beam and a second beam onto the surface of a detector. 60. A charged particle beam system according to any one of clauses 57 to 59, wherein a second lens is configured to apply a chromatic aberration to a first beam and a second beam to focus the first beam and the second beam onto a detector. 61. A charged particle beam system according to any one of clauses 34 to 60, wherein the system further includes a beam component. 62. A charged particle beam system according to Clause 61, wherein the beam component is configured to combine the first beam and the second beam before the first beam and the second beam are reflected from a second position on the sample surface. 63. A charged particle beam system according to clause 61 or 62, wherein the beam component is a mirror. 64. A charged particle beam system according to Clause 63, wherein a first beam passes through a mirror and a second beam is reflected from the mirror. 65. A method for measuring the properties of a sample in a charged particle beam apparatus, the method comprising: A first lens is used to emit a light beam from a light source to deliver the light beam to the surface of the sample, wherein the light beam is reflected from the surface of the sample; A second lens is used to focus the light beam reflected from the sample surface onto the detector surface to generate a first measurement; and The characteristics of the sample are determined using the first measurement. 66. The method according to Clause 65, wherein the beam is a visible beam. 67. The method according to clause 65 or 66, wherein the light source is a laser. 68. The method according to any one of clauses 65 to 67, wherein delivering the light beam to the surface of the sample includes collimating the light beam using a first lens. 69. The method according to any one of clauses 65 to 68, wherein the light beam is collimated when reflected from the surface of the sample. 70. The method according to any one of clauses 65 to 69, wherein the detector monitors the intensity change measured from a beam of light from the surface of the impact detector. 71. The method according to any one of clauses 65 to 70, wherein the first measurement provides information indicating the position of the beam of the impact detector. 72. The method according to any one of clauses 65 to 71, wherein the first measurement provides information representing the ratio. 73. The method according to Clause 72, wherein the ratio is a ratio of intensity values. 74. The method according to any one of clauses 65 to 73, wherein the characteristics of the sample include tilt characteristics. 75. The method according to any one of clauses 65 to 74, wherein emitting a beam from the light source further comprises: The controller is used to determine the first signal from the input signal; and A first signal is supplied to the light source to trigger the emission of a beam from the light source. 76. The method according to Clause 75, wherein the input signal includes an electrical signal. 77. The method according to Clause 76, wherein the electrical signal includes a clock signal. 78. The method according to Clause 77, wherein the first signal includes an electrical signal associated with a first edge of a clock signal. 79. The method according to Clause 77, wherein the first signal includes an electrical signal associated with a second edge of a clock signal. 80. The method according to any one of clauses 75 to 79, wherein the controller supplies a first signal to the light source and the detector. 81. The method according to any one of clauses 65 to 80, wherein the characteristics of the sample include the characteristics of a first location on the sample. 82. The method according to Clause 81, wherein a first position on the sample is within a local region surrounding a second position, wherein the second position is the location where a beam of charged particles is focused on the sample surface. 83. The method according to Clause 82, wherein the distance between the first position and the second position is less than or equal to 2 mm. 84. The method according to any one of clauses 65 to 83, wherein the charged particle beam device is a scanning electron microscope. 85. The method according to any one of clauses 65 to 83, wherein the charged particle beam device is a photolithography device. 86. A method for measuring a first characteristic and a second characteristic of a sample in a charged particle beam apparatus, the method comprising: Cause the first transmitter to emit the first beam; A first lens is used to transmit a first light beam to the surface of the sample, wherein the first light beam is reflected from the sample surface; The first beam is focused onto the surface of the detector using a second lens to generate a first measurement value; Cause the second transmitter to emit a second beam; The second beam is transmitted to the surface of the sample using a first lens, wherein the second beam is reflected from the surface of the sample. A second lens is used to focus a second beam onto the surface of the detector to generate a second measurement; and The first characteristic of the sample is determined using the first measurement, and the second characteristic of the sample is determined using the second measurement. 87. The method according to Clause 86, wherein the first beam has a wavelength different from that of the second beam. 88. The method according to Clause 86 or 87, wherein the first beam is a visible beam. 89. The method according to any one of clauses 86 to 88, wherein the second beam is a visible beam. 90. The method according to any one of clauses 86 to 89, wherein the first characteristic of the sample is a tilt characteristic and the second characteristic of the sample is a height characteristic. 91. The method according to any one of clauses 87 to 90, wherein the second beam has a wavelength smaller than that of the first beam. 92. The method according to any one of clauses 86 to 91, wherein using a first lens to transmit a first beam onto the surface of a sample includes collimating the first beam. 93. The method according to any one of clauses 86 to 92, wherein using a first lens to deliver a second beam onto the surface of a sample includes focusing the second beam. 94. The method according to any one of clauses 86 to 93, wherein the first emitter is a light source. 95. The method according to Clause 94, wherein the first transmitter is a laser. 96. The method according to any one of clauses 86 to 95, wherein the second emitter is a light source. 97. The method according to Clause 96, wherein the second transmitter is a laser. 98. The method according to any one of clauses 86 to 97, wherein the detector monitors intensity changes measured from a first or second beam from the surface of the impact detector. 99. The method according to any one of clauses 86 to 98, wherein a first measurement provides information indicating the position of a first beam of the impact detector, and a second measurement provides information indicating the position of a second beam of the impact detector. 100. The method according to Clause 99, wherein the first measurement provides information representing a first ratio, and the second measurement provides information representing a second ratio. 101. The method according to Clause 100, wherein the first ratio is a first ratio of the strength value and the second ratio is a second ratio of the strength value. 102. The method according to any one of clauses 86 to 101, wherein causing the first transmitter to emit the first beam comprises: The controller is used to determine the first signal from the input signal; and A first signal is supplied to the first transmitter to trigger the emission of the first beam. 103. The method according to any one of clauses 86 to 102, wherein causing the second transmitter to emit the second beam comprises: The controller is used to determine the second signal from the input signal; and A second signal is supplied to the second transmitter to trigger the emission of the second beam. 104. The method according to Clause 102 or 103, wherein the input signal includes an electrical signal. 105. The method according to Clause 104, wherein The input signals include clock signals; The first signal includes an electrical signal associated with the first edge of the clock signal; and The second signal includes an electrical signal associated with the second edge of the clock signal. 106. The method according to any one of clauses 86 to 105, wherein the first characteristic of the sample represents the characteristic of a first location on the sample. 107. The method according to any one of clauses 86 to 106, wherein the second characteristic of the sample represents the characteristic of the first location on the sample. 108. The method according to clause 106 or 107, wherein a first position on the sample is within a local region surrounding a second position, wherein the second position is the location where a beam of charged particles is focused on the sample surface. 109. The method according to Clause 108, wherein the distance between the first position and the second position is less than or equal to 2 mm. 110. The method according to any one of clauses 86 to 109, wherein the charged particle beam device is a scanning electron microscope. 111. The method according to any one of clauses 86 to 109, wherein the charged particle beam device is a photolithography device. 112. A non-transitory computer-readable medium including an instruction set executable by one or more processors of a computing device to cause the computing device to perform operations for measuring sample properties in a charged particle beam apparatus, the operations including: A first lens is used to emit a light beam from a light source to deliver the light beam to the surface of the sample, wherein the light beam is reflected from the surface of the sample; A second lens is used to focus the light beam reflected from the sample surface onto the detector surface to generate a first measurement; and The characteristics of the sample are determined using the first measurement. 113. A non-transitory computer-readable medium pursuant to Clause 112, wherein the light beam is a visible light beam. 114. A non-transitory computer-readable medium pursuant to Clauses 112 or 113, wherein the beam is a laser. 115. A non-transitory computer-readable medium according to any one of clauses 112 to 114, wherein delivering a beam of light to the surface of a sample includes collimating the beam using a first lens. 116. A non-transitory computer-readable medium according to any one of clauses 112 to 115, wherein the light beam is collimated when reflected from the surface of the sample. 117. A non-transient computer-readable medium according to any one of clauses 112 to 116, wherein the detector monitors intensity changes measured from a beam of light from the surface of the impact detector. 118. A non-transient computer-readable medium according to any one of clauses 112 to 117, wherein a first measurement provides information indicating the position of the beam of the impact detector. 119. A non-transitory computer-readable medium pursuant to any one of clauses 112 to 118, wherein a first measurement provides information representing a ratio. 120. A non-transitory computer-readable medium pursuant to Clause 119, wherein the ratio is a ratio of intensity values. 121. A non-transitory computer-readable medium according to any one of clauses 112 to 120, wherein the characteristics of the sample include tilting characteristics. 122. A non-transitory computer-readable medium according to any one of clauses 112 to 121, wherein the light beam emitted from the light source further comprises: The controller is used to determine the first signal from the input signal; and A first signal is supplied to the light source to trigger the emission of a beam from the light source. 123. A non-transitory computer-readable medium pursuant to Clause 122, wherein the input signal includes an electrical signal. 124. A non-transitory computer-readable medium pursuant to Clause 123, wherein electrical signals include clock signals. 125. A non-transitory computer-readable medium pursuant to Clause 124, wherein the first signal includes an electrical signal associated with a first edge of a clock signal. 126. A non-transitory computer-readable medium pursuant to Clause 124, wherein the first signal includes an electrical signal associated with a second edge of a clock signal. 127. A non-transitory computer-readable medium according to any one of clauses 122 to 126, wherein the controller supplies a first signal to the light source and the detector. 128. A non-transitory computer-readable medium according to any one of clauses 112 to 127, wherein the characteristics of the sample represent the characteristics of a first location on the sample. 129. A non-transitory computer-readable medium pursuant to Clause 128, wherein a first position on a sample is located within a local region surrounding a second position, wherein the second position is the location where a beam of charged particles is focused onto the sample surface. 130. A non-transitory computer-readable medium pursuant to Clause 129, wherein the distance between the first position and the second position is less than or equal to 2 mm. 131. A non-transitory computer-readable medium according to any one of clauses 112 to 130, wherein the charged particle beam device is a scanning electron microscope. 132. A non-transitory computer-readable medium according to any one of clauses 112 to 130, wherein the charged particle beam device is a photolithography device. 133. A non-transitory computer-readable medium including an instruction set executable by one or more processors of a computing device to cause the computing device to perform operations for measuring a first and a second characteristic of a sample in a charged particle beam apparatus, the operations including: Cause the first transmitter to emit the first beam; A first lens is used to transmit a first light beam to the surface of the sample, wherein the first light beam is reflected from the sample surface; The first beam is focused onto the surface of the detector using a second lens to generate a first measurement value; Cause the second transmitter to emit a second beam; The second beam is transmitted to the surface of the sample using a first lens, wherein the second beam is reflected from the surface of the sample. A second lens is used to focus a second beam onto the surface of the detector to generate a second measurement; and The first characteristic is determined using the first measurement value, and the second characteristic is determined using the second measurement value. 134. A non-transitory computer-readable medium pursuant to Clause 133, wherein the first beam has a wavelength different from that of the second beam. 135. A non-transitory computer-readable medium pursuant to Clauses 133 or 134, wherein the first beam is a visible beam. 136. A non-transitory computer-readable medium pursuant to any of clauses 133 to 135, wherein the second beam is a visible beam. 137. A non-transitory computer-readable medium pursuant to any one of clauses 133 to 136, wherein a first characteristic of the sample includes a tilt characteristic, and a second characteristic of the sample includes a height characteristic. 138. A non-transitory computer-readable medium pursuant to any one of clauses 134 to 137, wherein the second beam has a wavelength smaller than that of the first beam. 139. A non-transitory computer-readable medium according to any one of clauses 133 to 138, wherein using a first lens to transmit a first beam onto the surface of a sample includes collimating the first beam. 140. A non-transitory computer-readable medium according to any one of clauses 133 to 139, wherein using a first lens to deliver a second beam to the surface of a sample includes focusing the second beam. 141. A non-transitory computer-readable medium according to any one of clauses 133 to 140, wherein the first transmitter is a light source. 142. A non-transitory computer-readable medium pursuant to Clause 141, wherein the first transmitter is a laser. 143. A non-transitory computer-readable medium according to any one of clauses 133 to 142, wherein the second transmitter is a light source. 144. A non-transitory computer-readable medium pursuant to Clause 143, wherein the second transmitter is a laser. 145. A non-transient computer-readable medium according to any one of clauses 133 to 144, wherein the detector monitors intensity changes measured from a first or second beam from the surface of the impact detector. 146. A non-transitory computer-readable medium according to any one of clauses 133 to 145, wherein a first measurement provides information indicating the position of a first beam of an impact detector, and a second measurement provides information indicating the position of a second beam of an impact detector. 147. A non-transitory computer-readable medium pursuant to Clause 146, wherein a first measurement provides information representing a first ratio, and a second measurement provides information representing a second ratio. 148. A non-transitory computer-readable medium pursuant to Clause 147, wherein the first ratio is a first ratio of the intensity value and the second ratio is a second ratio of the intensity value. 149. A non-transitory computer-readable medium according to any one of clauses 133 to 148, wherein causing the first transmitter to emit a first beam comprises: The controller is used to determine the first signal from the input signal; and A first signal is supplied to the first transmitter to trigger the emission of the first beam. 150. A non-transitory computer-readable medium according to any one of clauses 113 to 149, wherein causing the second transmitter to emit a second beam comprises: The controller is used to determine the second signal from the input signal; and A second signal is supplied to the second transmitter to trigger the emission of the second beam. 151. A non-transitory computer-readable medium pursuant to Clauses 149 or 150, wherein the input signal includes an electrical signal. 152. A non-transitory computer-readable medium pursuant to Clause 151, wherein The input signals include clock signals; The first signal includes an electrical signal associated with the first edge of the clock signal; and The second signal includes an electrical signal associated with the second edge of the clock signal. 153. A non-transitory computer-readable medium according to any one of clauses 133 to 152, wherein a first characteristic of the sample represents a first characteristic at a first location on the sample, and wherein a second characteristic of the sample represents a second characteristic at the first location on the sample. 154. A non-transitory computer-readable medium pursuant to Clause 153, wherein a first position on a sample is within a local region surrounding a second position, and wherein the second position is the location where a beam of charged particles is focused onto the sample surface. 155. A non-transitory computer-readable medium pursuant to Clause 154, wherein the distance between the first position and the second position is less than or equal to 2 mm. 156. A non-transitory computer-readable medium according to any one of clauses 133 to 155, wherein the charged particle beam device is a scanning electron microscope. 157. A non-transitory computer-readable medium pursuant to any of clauses 133 to 155, wherein the charged particle beam apparatus is a photolithography apparatus. 158. A charged particle beam system according to any one of clauses 1 to 32, wherein the charged particle beam tool is a scanning electron microscope. 159. A charged particle beam system according to any one of clauses 1 to 32, wherein the charged particle beam tool is a photolithography apparatus. 160. A charged particle beam system according to any one of clauses 33 to 64, wherein the charged particle beam tool is a scanning electron microscope. 161. A charged particle beam system according to any one of clauses 33 to 64, wherein the charged particle beam tool is a photolithography apparatus.

[0084] It should be understood that the embodiments of this disclosure are not limited to the precise constructions described above and illustrated in the accompanying drawings, and various modifications and changes may be made without departing from its scope. This disclosure has been described in conjunction with various embodiments, and other embodiments of this disclosure will be apparent to those skilled in the art in light of the specification and practice of this disclosure herein. The specification and examples are intended to be considered exemplary only, and the true scope and spirit of this disclosure are indicated by the following claims.

Claims

1. A charged particle beam system, comprising: A charged particle beam tool having a circuit system configured to emit and focus a charged particle beam onto a first position on the surface of a sample; A transmitter module having a circuit system configured to emit a first beam and a second beam to reflect from a second position on the surface of the sample, wherein the transmitter module emits the first beam after receiving a first signal and emits the second beam after receiving a second signal; The detector module has a circuit system configured to collect the first beam to measure a first characteristic of the sample and to collect the second beam to measure a second characteristic of the sample; as well as A controller is communicatively connected to the transmitter module and the detector module, wherein the controller is configured to: determine the first signal and the second signal from the input signal, and supply the first signal and the second signal to the transmitter module.

2. The charged particle beam system of claim 1, wherein the second position on the surface of the sample is within a local region surrounding the first position.

3. The charged particle beam system according to claim 1, wherein the first beam has a wavelength different from that of the second beam.

4. The charged particle beam system of claim 1, wherein the first characteristic of the sample is a tilt characteristic, and the second characteristic is a height characteristic.

5. The charged particle beam system according to claim 1, wherein... The input signal includes a clock signal; The first signal includes an electrical signal associated with a first edge of the clock signal; and The second signal includes an electrical signal associated with the second edge of the clock signal.

6. The charged particle beam system according to claim 1, wherein the emitter module comprises: A first transmitter is configured to emit the first beam in response to receiving the first signal; The second transmitter is configured to emit the second beam in response to receiving the second signal; as well as A first lens is configured to transmit the first beam and the second beam to the second position on the sample.

7. The charged particle beam system of claim 6, wherein the first lens is configured to collimate the first beam and focus the second beam.

8. The charged particle beam system according to claim 1, wherein the detector module comprises: Detector; as well as The second lens is configured to collect the first beam and the second beam reflected from the sample and to transmit the first beam and the second beam to the detector.

9. The charged particle beam system of claim 8, wherein the second lens is configured to focus the first beam and the second beam onto the surface of the detector.

10. The charged particle beam system of claim 8, wherein the second lens is configured to apply a chromatic power difference to the first beam and the second beam to focus the first beam and the second beam onto the detector.

11. The charged particle beam system of claim 8, wherein the detector comprises: One or more sections are used to monitor intensity changes from the first or second beam impacting the detector.

12. The charged particle beam system of claim 8, wherein the detector outputs a third signal.

13. The charged particle beam system of claim 12, wherein the third signal provides information indicating the position of the first or second beam impacting the detector.

14. The charged particle beam system of claim 13, wherein the third signal is used to calculate the first characteristic of the sample or the second characteristic of the sample.

15. A non-transitory computer-readable medium comprising an instruction set executable by one or more processors of a computing device to cause the computing device to perform operations for measuring properties of a sample in a charged particle beam apparatus, the operations comprising: A light beam is emitted from a light source to deliver the light beam to the surface of the sample using a first lens, wherein the light beam is reflected from the surface of the sample; The second lens is used to focus the light beam reflected from the surface of the sample onto the surface of the detector to generate a first measurement value; as well as The first measurement value is used to determine the characteristic of the sample.

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