Detection device

Abstract

The utility model provides a kind of detection device, it includes the electron beam source configured as emitting electron beam, and the objective lens group configured as based on electron beam and electron beam are projected to target area in branch.The detection device further includes the detector between objective lens group and target area and is configured as detecting backscattered electron beam from target area.The detector includes the substrate with the opening of electron beam passing through, and multiple sensing units are arranged on the substrate and surround the opening.Each sensing unit in multiple sensing units has the normal direction inclined to the normal direction of substrate.

Description

Technical Field

[0001] The embodiments of this utility model relate to a detection device. Background Technology

[0002] The integrated circuit (IC) industry has experienced rapid growth. Technological advancements in IC materials and design have yielded several generations of ICs, each with smaller and more complex circuits than the previous generation. However, these advancements have also increased the complexity of IC fabrication and manufacturing, requiring similar developments in these areas to achieve the same level of progress. In the evolution of ICs, functional density (the number of interconnects per unit chip area) typically increases, while geometry (the smallest element (or line) that can be created using manufacturing processes) decreases.

[0003] Manufacturing integrated circuits typically involves processing substrates (such as semiconductor wafers) through numerous manufacturing processes to form various features and devices. The substrates undergo hundreds of manufacturing processes, which may include, but are not limited to: photolithography, plasma etching, wet etching, chemical vapor deposition (CVD), physical vapor deposition (PVD), sputtering deposition, chemical-mechanical polishing (CMP), ion implantation, annealing, variations thereof, and similar processes.

[0004] The need for ever-increasing device density persists. Therefore, some manufacturing processes may operate near their capability limits. Due to the large number of devices processed and the pushing of process limits, some devices manufactured based on the same semiconductor wafer may contain defects or imperfections. To ensure quality, manufacturers inspect completed devices (or wafers at each stage of manufacturing) to identify those that fail to meet manufacturer standards. In some applications, this inspection may be based on optical inspection devices or electron beam inspection devices. Utility Model Content

[0005] This invention provides a detection device, comprising: an electron beam source configured to emit an electron beam; an objective lens assembly configured to project electron beams onto a target region based on the electron beam; and a detector located between the objective lens assembly and the target region, configured to detect backscattered electrons from the target region, the detector comprising: a substrate having an opening through which the electron beam passes; and a plurality of sensing units disposed on the substrate and surrounding the opening, each of the plurality of sensing units having a normal direction inclined relative to the normal direction of the substrate.

[0006] This invention provides a detection device comprising: an electron beam source configured to emit an electron beam; an objective lens assembly configured to project a plurality of electron beams onto a target region based on the electron beam; and a plurality of detectors located between the objective lens assembly and the target region and configured to detect backscattered electrons from the target region, wherein the plurality of electron beams comprises groups of electron beams that are spatially staggered and temporally distinguishable from each other. Attached Figure Description

[0007] The best understanding of the present invention will be achieved by reading the following detailed description in conjunction with the accompanying drawings. It should be noted that, according to industry standard practice, the various features are not drawn to scale. In fact, for clarity of explanation, the dimensions of the various features may be arbitrarily increased or decreased.

[0008] Figure 1 This is a simplified block diagram of an electron beam detection apparatus according to some embodiments.

[0009] Figure 2A This is a cross-sectional view of two detectors that can be used in an electron beam detection apparatus according to some embodiments.

[0010] Figure 2B This is a bottom view of a detector that can be used in an electron beam detection apparatus according to some embodiments.

[0011] Figure 2C This is a cross-sectional view of a sensing unit within a detector that can be used in an electron beam detection apparatus according to some embodiments.

[0012] Figure 3A This is a diagram illustrating an example of a grouping pattern for electron beamlets of an electron beam detection device arranged in a spatial domain, according to some embodiments.

[0013] Figures 3B to 3D This is a timing diagram of an example arrangement of electron beam splitters in an electron beam detection device in the time domain, based on some embodiments.

[0014] Figure 4 This is a flowchart of a detection method based on some embodiments.

[0015] Figure 5 This is a flowchart of another detection method based on some embodiments. Detailed Implementation

[0016] This utility model provides numerous different embodiments or examples for implementing various features of the utility model. Specific examples of components and arrangements are described below to simplify the utility model. Of course, these are merely examples and are not intended to be limiting. For example, the following description of a first feature formed on or on a second feature may include embodiments in which the first and second features are formed in direct contact, and may also include embodiments in which additional features may be formed between the first and second features, thereby preventing direct contact between the first and second features. Furthermore, reference numerals and / or letters may be repeated in various examples of this utility model. Such repetition is for simplicity and clarity and does not in itself indicate a relationship between the various embodiments and / or configurations discussed.

[0017] Furthermore, for ease of explanation, spatially relative terms such as “beneath,” “below,” “lower,” “above,” “upper,” and similar expressions may be used herein to describe the relationship between one device or feature shown in the figures and another device or feature. These spatially relative terms are intended to encompass different orientations of the device in use or operation, in addition to those shown in the figures. The device may have other orientations (rotated 90 degrees or in other orientations), and the spatially relative descriptive terms used herein may be interpreted accordingly. Furthermore, the term “made of” may mean “including” or “consisting of.” In this invention, the phrase “one of A, B and C” means “A, B and / or C” (A, B, C, A and B, A and C, B and C or A, B and C), and unless otherwise stated, does not mean selecting an element from A, selecting an element from B and selecting an element from C.

[0018] Figure 1 This is a simplified block diagram of an electron beam detection apparatus 100 according to some embodiments. In some embodiments, the electron beam detection apparatus 100 is a non-limiting example, and the plurality of elements of the electron beam detection apparatus 100 are... Figure 1 The Chinese characters are simplified or omitted.

[0019] exist Figure 1In this embodiment, the electron beam detection device 100 includes an electron beam source 110, a condenser lens 120, an objective lens group 130, and a plurality of detectors 140. In some embodiments, the electron beam detection device 100 is configured to detect a sample (e.g., a wafer 150) by projecting a plurality of electron beamlets onto a target region of the sample (e.g., a target region 152 of the wafer 150) and detecting back-scattered electrons (BSE).

[0020] In some embodiments, electron beam source 110 is configured to emit electron beam 162 (also referred to as the main electron beam). In some embodiments, electron beam source 110 includes an electron generator or electron gun. In some embodiments, for a detection process based on detecting backscattered electrons, the energy of electron beam 162 is 3000 electron volts (eV) or greater. In some embodiments, condenser lens 120 is configured to bend or shape electron beam 162 such that electrons in electron beam 162 move parallel to objective lens group 130. In some embodiments, condenser lens 120 includes one or more coils configured to generate a magnetic field to bend the electron trajectory in electron beam 162.

[0021] In some embodiments, objective lens group 130 is configured to project a plurality of electron beams 166 onto a target region (e.g., target region 152) based on electron beam 162. In some embodiments, objective lens group 130 is capable of converting electron beam 162 into up to 100 or more electron beams 166. In some embodiments, objective lens group 130 includes a plurality of microelectromechanical system (MEMS) devices configured as deflecting devices and / or beam stopping devices associated with the plurality of electron beams. In some embodiments, each MEMS device is associated with a corresponding electron beam of electron beam 166 and includes one or more aperture limiting layers, electron deflectors, astigmatism correctors, or combinations thereof.

[0022] In some embodiments, a plurality of detectors 140 are configured to detect backscattered electrons from a target region, which are generated from the interaction of electron beam 166 with a sample (e.g., wafer 150). In some applications, to detect defects in the sample (e.g., wafer 150) based on the detection of backscattered electrons, electron beam 162 has a high energy level (e.g., greater than 3000 eV), so the energy of the resulting backscattered electrons is still too high to be effectively redirected to detectors at an angle away from objective lens group 130. Therefore, a plurality of detectors 140 are configured between objective lens group 130 and the sample. In some embodiments, each detector of the plurality of detectors 140 is configured in association with a corresponding electron beam of electron beam 166. In some embodiments, each detector of the plurality of detectors 140 includes an opening through which the associated electron beam passes. In some embodiments, each detector of the plurality of detectors 140 further includes one or more sensing units configured to convert the detected electrons into a voltage signal or a current signal.

[0023] In some embodiments, a processing device (not shown) is communicatively coupled to a condenser lens 120 and / or an objective lens group 130 to control the power, timing, and / or trajectory of a plurality of electron beam splitters 166. In some embodiments, the processing device or different processing devices (not shown) are communicatively coupled to a plurality of detectors 140 to collect voltage or current signals representing electrons detected by their sensing units and to obtain one or more scan images based on processing the collected voltage or current signals.

[0024] In some embodiments, in a multi-electron-beam detection system based on electron beam detection device 100, each of the plurality of detectors 140 receives not only backscattered electrons from its associated electron beam, but also other backscattered electrons from adjacent electron beams. Therefore, the resulting image from each detector corresponds to the superposition of backscattered electrons from the associated electron beam and adjacent electron beams, a phenomenon also known as the crosstalk effect or crosstalk noise. In some embodiments, crosstalk noise interferes with the effectiveness of detecting backscattered electrons corresponding to defects in the sample (e.g., wafer 150).

[0025] In some applications, placing the sample (e.g., wafer 150) closer to the multiple detectors 140 can reduce crosstalk noise (e.g., distance less than 0.5 mm), but increases the chance of arcing between the multiple detectors 140 and the sample, thereby increasing the chance of damaging the sample during detection and / or rendering the detection results unusable. In some applications, increasing the spacing between adjacent electron beams (e.g., greater than 50 micrometers, μm) can also reduce crosstalk noise. However, in some applications, increasing the spacing between adjacent electron beams reduces the throughput of the detection process because the coverage with respect to beam deflection is limited (e.g., a larger spacing corresponds to moving the sample and stage to scan all areas). In some embodiments, controlling crosstalk noise is a bottleneck in the development of multi-electron beam detection systems.

[0026] In some embodiments, to reduce crosstalk noise based on the first concept, the sensing element of detector 140 is configured to collect backscattered electrons at a specific angle. For example, the detector is based on a pixelated semiconductor sensing element array, and each sensing surface of each sensing element is tilted at a corresponding angle (e.g., ranging from 5 degrees to 45 degrees). Therefore, backscattered electrons from adjacent beams reach the sensing element of the detector from the side or back of the sensing element, locations unsuitable for effective electron detection, thereby reducing crosstalk noise. In this invention, Figures 2A to 2C This includes non-restrictive instances corresponding to the first concept.

[0027] In some embodiments, to reduce crosstalk noise based on the second concept, electron beam splitting 162 is pulsed electron beam splitting, with these beams spatially interleaved and temporally distinguishable. In some embodiments, the objective group 130 is capable of individually controlling the switching of each electron beam to create pulsed electron beam splitting. In some embodiments, where the irradiation durations of adjacent electron beams partially overlap, the scanned image can be improved based on post-processing of the detected signals to separate detected electrons from different beams. In this invention, Figures 3A to 3D This includes non-restrictive instances corresponding to the second concept.

[0028] Figure 2A This is a cross-sectional view of two detectors 210 and 220 that can be used in an electron beam detection apparatus according to some embodiments. In some embodiments, detectors 210 and 220 can be used as Figure 1 The detector of the electron beam detection device 100. Figure 2A In this configuration, the detector 210 is located between the objective lens group 130 and the target region 152 (e.g., the upper surface 230 of the wafer, such as...). Figure 1Between the wafer 150 in the electron beam detection device 100, an electron beam splitter 212 is configured to pass through and to detect backscattered electrons 214 from the target region. Similarly, a detector 220 is located between the objective lens group 130 and the target region 152 (e.g., the upper surface 230), configured to allow the electron beam splitter 222 to pass through and to detect backscattered electrons 224 from the target region. In some embodiments, all detectors of the plurality of detectors 140 of the electron beam detection device 100 are based on the same hardware configuration. Here, detector 210 is further described as a non-limiting example of the plurality of detectors 140.

[0029] exist Figure 2A In this embodiment, detector 210 includes a substrate 242 having an opening 244 through which an associated electron beam splitter 212 passes. Detector 210 also includes a plurality of sensing units (two of which are identified by circles with reference numbers 246 and 247) configured on the substrate 242 and surrounding the opening 244. In some embodiments, each of the plurality of sensing units is based on the same hardware configuration. In some embodiments, each of the plurality of sensing units has a sensing direction corresponding to a normal direction (e.g., direction 248) tilted relative to the normal direction 249 of the substrate 242. In some embodiments, the electron beam splitter 212 passes through the opening 244 along an axis 251 parallel to the normal direction 249 of the substrate 242. Figure 2A In the detector 210, each of the plurality of sensing units has a sensing surface that faces the target region (e.g., target region 152, or the upper surface 230 of the wafer) and is tilted toward axis 251. In some embodiments, the tilt angle of each sensing unit ranges from 5 degrees to 45 degrees.

[0030] Figure 2B This is a bottom view of a detector in an electron beam detection apparatus, according to some embodiments. In some embodiments, Figure 2B The detector in the middle corresponds to Figure 2A The detector 210 in the middle. Figure 2B Zhongyu Figure 2A Identical or similar elements are given the same reference number, so their detailed descriptions are simplified or omitted.

[0031] exist Figure 2B In this configuration, detector 210 is arranged to receive an electron beam (e.g., along axis 251, identified by a point indicating the direction of exit from the plane of the paper) passing through opening 244. Figure 2A Electron beam splitting in (212). Figure 2BIn this detector 210, the substrate 242 is divided into regions 252 to 257 surrounding the opening 244. In some embodiments, a plurality of sensing units (e.g., including sensing units 246 and 247) have a subset of sensing units configured in a rotationally symmetric manner about the opening 244 in the respective regions 252 to 257. In this non-limiting example, the detector 210 includes six regions 252 to 257, and each region includes five rows of sensing units. In some embodiments, the number of regions surrounding the opening 244 and the number of rows of sensing units are related to... Figure 2B The examples are different.

[0032] Figure 2C This is a cross-sectional view of a sensing unit that can be used in a detector in an electron beam detection apparatus, according to some embodiments. As a non-limiting example, Figure 2C The sensing unit in the middle corresponds to Figure 2A Sensing unit 246 on substrate 242. Figure 2C Zhongyu Figure 2A Identical or similar elements are given the same reference numerals, therefore their detailed descriptions are simplified or omitted. In some embodiments, each of the plurality of sensing units of the detector 210 is based on Figure 2C Hardware configuration in the example. In some embodiments, Figures 2A to 2C Each sensing unit in the system is a solid-state sensing unit.

[0033] exist Figure 2C In this design, sensing unit 246 includes a sensing diode (represented by block 262) having a sensing surface 263 at the front portion of sensing unit 246. Sensing unit 246 also includes a signal pick-up circuit (represented by block 264) at the rear portion of sensing unit 246. Furthermore, in... Figure 2C In this embodiment, the sensing unit 246 includes an insulating seal 266 covering a portion of the sensing unit 246. In some embodiments, a gap 267 is defined between the substrate 242 and the back surface 268 of the signal pickup circuit 264, and the insulating seal 266 extends into the gap 267 and covers the back surface 268 of the signal pickup circuit 264. In some embodiments, the signal pickup circuit 264 includes an amplification circuit or an operational amplifier. In some embodiments, the insulating seal 266 comprises a material of silicon oxide, silicon nitride, polymer, ceramic, epoxy resin, or a combination thereof. In some embodiments, the sensing diode (represented by block 262) has a width ranging from 15 μm to 30 μm and a thickness ranging from 5 μm to 10 μm. In some embodiments, the signal pickup circuit (represented by block 264) has a width ranging from 15 μm to 30 μm and a thickness ranging from 5 μm to 10 μm.

[0034] exist Figures 2A to 2C In a non-limiting example, each detector (e.g., detector 210) includes an array of pixelated tilt sensing units (e.g., sensing units 246 and 247). In some embodiments, each sensing unit is configured on a substrate (e.g., substrate 242) and has a tilt angle relative to the normal direction of the substrate (e.g., normal direction 249). Figures 2A to 2C Each sensing unit's sensing surface (e.g., sensing surface 263) is tilted toward an axis (e.g., the y-axis), along which the trajectory of the corresponding electron beam is defined. Figure 2A In one example, the tilted sensing surface of each sensing unit of the detector 210 is configured to receive backscattered electrons 214 from the interaction between the sample and the associated electron beam 212.

[0035] In addition, Figure 2A In some instances, due to the tilted sensing surface, the sensing elements (e.g., sensing element 247) of the detector 210 located in a region adjacent to the detector 220 are not configured to effectively collect backscattered electrons 226 from the interaction between the sample and the electron beam 222 associated with the detector 220. In some embodiments, the insulating seal of the sensing surface toward sensing elements of adjacent detectors (e.g., sensing elements 247 and adjacent sensing elements in the same region as the detector 210) is configured to protect the side and rear portions of the respective sensing elements from the influence of backscattered electrons from adjacent electron beams.

[0036] In addition, Figure 2A In the example, although the sensing unit (e.g., sensing unit 246) of the detector 210, which is located in a region far from the detector 220, appears to be able to receive backscattered electrons 228 from the interaction between the sample and the electron beam 222, the overall number of backscattered electrons from the electron beam 222 is still significantly reduced because only a portion of the sensing unit of the detector 210 is configured at an angle that can be used to receive large-angle backscattered electrons from the electron beam 222.

[0037] Therefore, based on Figures 2A to 2C In this example, the detector used in the electron beam detection apparatus has a reduced chance of receiving backscattered electrons from adjacent electron beams. Thus, the crosstalk noise detected by the detector (e.g., detector 210) of the electron beam detection apparatus is reduced. Furthermore, based on the reduced crosstalk noise, the distance between the detector and the sample is maintained sufficiently far from the sample (e.g., a distance greater than 0.5 mm) to reduce the chance of arcing between the detector and the sample without sacrificing image quality.

[0038] Figure 3AThis is a diagram of an example 310 of a grouping pattern for electron beam splitting of an electron beam detection device arranged in a spatial domain, according to some embodiments. In some embodiments, the electron beam splitting of the electron beam detection device (e.g., Figure 1 The multiple electron beams (166) in the detector are divided into multiple electron beam groups that are spatially interleaved and temporally distinguishable to reduce the chance of the detector receiving backscattered electrons from adjacent beams.

[0039] exist Figure 3A In this diagram, each hexagon represents the corresponding position of a detector in an electron beam detection device (e.g., electron beam detection device 100). Figure 1 As shown in the examples, each detector is configured for use in association with a corresponding electron beam splitter. In some embodiments, Figure 3A Each detector, represented by a hexagon, corresponds to a single sensing unit detector with a central opening through which the associated electron beam passes. In some embodiments, Figure 3A Each detector represented by a hexagon in the diagram corresponds to an array of tilt sensing units (e.g., Figures 2A to 2C (Examples in the text) or detectors with a non-tilted array of sensing elements (e.g., the normal direction of the sensing elements is parallel to the direction of the associated electron beam trajectory). In this example, the detectors of the electron beam detection device are arranged in a hexagonal honeycomb pattern.

[0040] exist Figure 3A In this context, the numbers within the hexagons represent the grouping of the corresponding beams in the spatial domain. In some embodiments, the objective lens group of the electron beam detection device (e.g., Figure 1 The objective group 130 is configured to convert the main electron beam (e.g., electron beam 162) into electron beams (e.g., electron beam 166) arranged in a central spatial pattern of a detector-based hexagonal honeycomb pattern. As a result, the observable electron beam positions on the target region correspond to the vertices of the triangular mosaic honeycomb pattern. In some embodiments, the electron beam groups correspond to four groups, in... Figure 3A The numbers are 0, 1, 2, and 3. In this non-limiting example, at least one electron beam from each of the four groups is spatially surrounded by six electron beams from the other three groups. For example, the electron beam corresponding to hexagon 312, belonging to group '3', is surrounded by six electron beams from the other three groups, including two electron beams corresponding to hexagons 313 and 314 and belonging to group '0', two electron beams corresponding to hexagons 315 and 316 and belonging to group '1', and two electron beams corresponding to hexagons 317 and 318 and belonging to group '2'.

[0041] In addition, the objective lens assembly of the electron beam detection device (e.g., Figure 1The objective group 130 is configured to convert the electron beam into electron beam splitting groups, such that each electron beam splitting group begins at a different time. In some embodiments, during the time interval in which the electron beams of one group are present, the presence of other groups is avoided or reduced to reduce the chance of the detector receiving crosstalk noise.

[0042] Figures 3B to 3D The electron beam splitting of the electron beam detection device is arranged in the time domain (e.g., based on...). Figure 3A A timing diagram of the arrangement of multiple electron beams in an example, based on some embodiments. Figures 3B to 3D In this diagram, time is represented by the horizontal axis, while the on / off state of the electron beam for each group is represented by the vertical axis. In this non-limiting example, the electron beam is divided into four groups (e.g., Figure 3A Pulsed electron beam splitting (groups '0', '1', '2', and '3' in the dataset). In some embodiments, the electron beam splitting groups start and end sequentially one after another. In some embodiments, each electron beam splitting group lasts for the same duration.

[0043] exist Figures 3B to 3D In the diagram, each rectangular bar represents the presence of a corresponding electron beam group, and a reference number (one of 0, 1, 2, and 3) indicates which group the rectangular bar represents. Figures 3B to 3D In the middle, each rectangular bar has a pulse width T (e.g., Figure 3B (as shown in the diagram). In some embodiments, the pulse width T ranges from 1 nanosecond (ns) to 10 ns. In some embodiments, the pulse width T is set based on the detector's sensitivity. In some embodiments, the objective group converts the electron beam into electron beam splitters, such that each electron beam splitter begins at a different time.

[0044] Figure 3B This is a timing diagram of a first example arrangement 320 of electron beam splitting. In the first example arrangement 320, electron beam splitting groups are arranged sequentially within one scanning cycle, with adjacent groups separated in the time domain by corresponding time gaps. In this example, the time gap between two adjacent electron beam splitting groups can be measured based on the time from the end of one electron beam splitting group to the start of the subsequent electron beam splitting group. In the first example arrangement 320, adjacent groups are separated by corresponding time gaps of duration τ1, where τ1 is greater than zero. In some embodiments, the positive time gap τ1 is set to ensure sufficient separation and processing time for the received backscattered electron signals from different electron beam splitting groups.

[0045] Figure 3CThis is a timing diagram of a second instance arrangement 330 for electron beam splitting. In the second instance arrangement 330, electron beam groups are sequentially arranged in the time domain within one scan cycle, one group immediately following another. In the second instance arrangement 330, the duration τ2 of the time gap (defined based on the end time of one electron beam group to the start time of the subsequent electron beam group) between adjacent groups is zero. In some embodiments, the second instance arrangement 330 is a viable option compared to the first instance arrangement 320, and depends on the ability to process the received backscattered electron signals in a timely manner, offering the advantage of a shorter scan cycle.

[0046] Figure 3D This is a timing diagram of a third instance arrangement 340 for electron beam splitting. In the third instance arrangement 340, electron beam groups are arranged sequentially within one scan cycle, with adjacent groups partially overlapping in the time domain. In the third instance arrangement 340, the duration τ3 of the time gap (defined based on the end time of one electron beam group to the start time of the subsequent electron beam group) between adjacent groups is less than zero. In some embodiments, the third instance arrangement 340 is also a viable option compared to the first instance arrangement 320 and the second instance arrangement 330, and depending on the ability to separate the received backscattered electron signal from crosstalk noise, offering the advantage of a shorter scan cycle.

[0047] In some embodiments, depending on such Figures 3B to 3D The diagram illustrates different arrangements of electron beam splitting modes in the time domain, where the signals on the detector remain separable or are expected to be separable through appropriate signal processing algorithms. In some embodiments, the time gap τ1 or τ3 is constant or dynamically adjustable. In some embodiments, the electron beam detection device is configured such that each portion of the target region is still expected to receive an equal electron dose in each scan cycle.

[0048] Therefore, the objective lens assembly of the electron beam detection device is configured based on Figures 3A to 3D The example in the paper converts the main electron beam into multiple electron beams, separating the presence of adjacent beams in the time domain to reduce the chance of crosstalk noise. Furthermore, based on the reduced crosstalk noise, the distance between the detector and the sample is kept sufficiently far away (e.g., greater than 0.5 mm) to reduce the chance of arcing between the detector and the sample without sacrificing image quality.

[0049] Figures 2A to 2C This includes non-limiting examples of reducing crosstalk noise based on a detector with an array of tilt sensing units (i.e., the first concept). Figures 3A to 3DThis includes non-limiting examples of reducing crosstalk noise by converting the main electron beam into multiple spatially staggered and temporally distinguishable electron beam groups based on the objective lens group (i.e., the second concept). In some embodiments, the electron beam detection device is configured to incorporate... Figures 2A to 2C Teaching through examples Figures 3A to 3D The teachings of examples, or both, to reduce crosstalk noise and / or avoid or reduce the arcing effect between the detector and the sample.

[0050] Figure 4 This is a flowchart of a detection method 400 according to some embodiments. In some embodiments, various operations of method 400 are related to... Figure 1 The electron beam detection device 100 is combined and executed, wherein multiple detectors 140 are based on Figures 2A to 2C Implementation examples. For example... Figure 4 As shown, method 400 corresponds to an instance based on the first concept and includes blocks 410 to 430.

[0051] In box 410, the electron beam source (e.g., Figure 1 The electron beam source 110 in the middle emits an electron beam (e.g., Figure 1 (electron beam 162). In some embodiments, the energy of the electron beam is 3000 eV or greater.

[0052] In box 420, the objective lens group (e.g., Figure 1 The objective lens group 130 in the middle) is based on an electron beam, and splits at least one electron beam (e.g., Figure 1 Multiple electron beams 166 are projected onto the target region (e.g., Figure 1 On the target region 152). In some embodiments, the objective lens group includes a plurality of microelectromechanical systems (MEMS) devices configured to be associated with a plurality of electron beam splitters or beam stopping devices. In some embodiments, each MEMS device is associated with a corresponding electron beam splitter and includes one or more limiting aperture layers, electron deflectors, astigmatism correctors, or combinations thereof.

[0053] In box 430, a detector (e.g., one of a plurality of detectors 140, based on) is located between the objective lens group and the target region. Figures 2A to 2B An example of detector 210 in which the sensing unit is based Figure 2C An example of sensing unit 246 in the image) detects backscattered electrons from the target region (e.g., Figure 2A Backscattered electrons 214 in the detector. In some embodiments, the electron beam (e.g., electron beam 212) passes through an opening (e.g., opening 244) in the substrate (e.g., substrate 242) of the detector. In some embodiments, the detection of backscattered electrons is performed by a plurality of sensing units of the detector, and the normal direction of the sensing units (e.g., Figure 2Aand Figure 2C The direction 248 in the middle is relative to the normal direction of the substrate (e.g., Figure 2A and Figure 2C The normal direction in the middle is inclined at 249).

[0054] In some embodiments, the detector is separated from the target area by at least 0.5 mm. In some embodiments, method 400 further includes an insulating seal (e.g., covering at least one side portion of the sensing unit covering the detector and the back surface of the sensing unit covering the detector) Figure 2C The insulating seal 266 in the middle blocks at least one backscattered electron (e.g., backscattered electron 226) from another electron beam (e.g., electron beam 222).

[0055] like Figures 2A to 2C As discussed in the examples, based on method 400, the crosstalk noise detected by the detector of the electron beam detection device (e.g., detector 210) is reduced. Furthermore, based on the reduced crosstalk noise, the distance between the detector and the sample is maintained sufficiently far from the sample (e.g., a distance greater than 0.5 mm) to reduce the chance of arcing between the detector and the sample without sacrificing image quality.

[0056] Figure 5 This is a flowchart of another detection method 500 according to some embodiments. In some embodiments, various operations of method 500 are related to... Figure 1 The electron beam detection device 100 in the middle is executed together, wherein the objective lens group 130 is based on Figures 3A to 3D Implementation examples. For example... Figure 5 As shown, method 500 corresponds to an instance based on the second concept and includes blocks 510 to 530.

[0057] In box 510, the electron beam source (e.g., Figure 1 The electron beam source 110 in the middle emits an electron beam (e.g., Figure 1 (electron beam 162). In some embodiments, the energy of the electron beam is 3000 eV or greater.

[0058] In box 520, the objective lens group (e.g., Figure 1 The objective lens group 130 in the middle is based on an electron beam, which splits multiple electron beams (e.g., Figure 1 Multiple electron beams 166 are projected onto the target region (e.g., Figure 1 On the target region 152). In box 530, multiple detectors (e.g., multiple detectors 140) located between the objective lens group and the target region detect backscattered electrons from the target region.

[0059] In some embodiments, the objective lens assembly includes a plurality of microelectromechanical systems (MEMS) devices configured to be associated with deflection or beam-stopping devices for a plurality of electron beam splitters. In some embodiments, each MEMS device is associated with a corresponding electron beam splitter and includes one or more limiting aperture layers, electron deflectors, astigmatism correctors, or combinations thereof. In some embodiments, based on Figures 3A to 3D In the example, multiple electron beams comprise spatially interleaved and temporally distinguishable groups of electron beams.

[0060] In some embodiments, the objective lens group converts the electron beam into an electron beam splitter based on the spatial arrangement of multiple detectors, wherein the multiple detectors are based on a hexagonal honeycomb pattern (e.g., Figure 3A The electron beam splitters are arranged in a hexagonal honeycomb pattern. In some embodiments, the electron beam splitters correspond to four groups (e.g., ...). Figure 3A (Groups '0', '1', '2', and '3' in the four groups). In some embodiments, at least one electron beam from each of the four groups is spatially surrounded by six electron beams from the other three groups.

[0061] In some embodiments, the objective lens group converts the electron beam into electron beam splitters, such that each electron beam splitter begins at a different time. In some embodiments, the electron beam splitters are arranged sequentially in the time domain, with adjacent groups separated by corresponding time intervals. In some embodiments, the electron beam splitters are arranged sequentially in the time domain, with one group immediately following another. In some embodiments, the electron beam splitters are arranged sequentially, with adjacent groups partially overlapping in the time domain.

[0062] like Figures 3A to 3D As discussed in the examples, based on method 500, the crosstalk noise detected by the detector of the electron beam detection device (e.g., detector 210) is reduced. Furthermore, based on the reduced crosstalk noise, the distance between the detector and the sample is maintained sufficiently far from the sample (e.g., a distance greater than 0.5 mm) to reduce the chance of arcing between the detector and the sample without sacrificing image quality.

[0063] In some aspects, the detection apparatus includes an electron beam source configured to emit an electron beam. The detection apparatus includes an objective lens assembly configured to project electron beams onto a target region based on the electron beam. The detection apparatus also includes a detector located between the objective lens assembly and the target region and configured to detect backscattered electron beams from the target region. The detector includes a substrate having an opening through which the electron beams pass, and a plurality of sensing units disposed on the substrate and surrounding the opening. Each of the plurality of sensing units has a normal direction tilted relative to the normal direction of the substrate.

[0064] In some embodiments, the substrate is divided into regions surrounding the opening, and the plurality of sensing units have a subset of sensing units configured in a rotationally symmetrical manner in the respective regions of the region about the opening. In some embodiments, the electron beam is split along an axis through the opening, and each of the plurality of sensing units has a sensing surface facing the target region and inclined toward the axis. In some embodiments, each of the plurality of sensing units includes: a sensing diode having a sensing surface at the front of the respective sensing unit; a signal pickup circuit located at the rear of the respective sensing unit; and an insulating seal covering the side of the respective sensing unit. In some embodiments, for each of the plurality of sensing units, a gap is defined between the substrate and the back surface of the signal pickup circuit of the respective sensing unit, and the insulating seal extends into the gap and covers the back surface of the signal pickup circuit of the respective sensing unit. In some embodiments, for each of the plurality of sensing units, the signal pickup circuit includes an amplification circuit or an operational amplifier, and the insulating seal includes a material containing silicon oxide, silicon nitride, a polymer, ceramic, epoxy resin, or a combination thereof.

[0065] In some aspects, the detection apparatus includes an electron beam source configured to emit an electron beam. The detection apparatus includes an objective lens assembly configured to project multiple electron beams onto a target region based on the electron beam. The detection apparatus also includes multiple detectors located between the objective lens assembly and the target region and configured to detect backscattered electrons from the target region. The multiple electron beams include spatially staggered and temporally distinguishable groups of electron beams.

[0066] In some embodiments, the objective lens group includes a plurality of microelectromechanical systems (MEMS) devices configured as deflection or beam-stopping devices associated with the plurality of electron beams. In some embodiments, the plurality of detectors are arranged in a hexagonal honeycomb pattern, and the objective lens group is configured to convert the electron beam into electron beams spatially arranged at the center of the hexagonal honeycomb pattern, the groups of electron beams corresponding to four groups, and at least one electron beam in each of the four groups being spatially surrounded by six electron beams from the other three groups of the four groups. In some embodiments, the objective lens group is configured to convert the electron beam into the groups of electron beams such that each of the groups of electron beams begins at a different time. In some embodiments, the groups of electron beams begin and end sequentially one after another, and each of the groups of electron beams lasts for the same duration. In some embodiments, the groups of electron beams are arranged sequentially in the time domain, with adjacent groups separated by corresponding time gaps; the groups of electron beams are arranged sequentially in the time domain, with one group immediately following another; or the groups of electron beams are arranged sequentially in the time domain, with adjacent groups partially overlapping.

[0067] In some aspects, the detection method includes emitting an electron beam from an electron beam source. The method includes projecting an electron beam, based on an objective lens assembly, onto a target region. The method also includes detecting backscattered electrons from the target region by a detector located between the objective lens assembly and the target region. The electron beam passes through an opening in the detector substrate. Detection of backscattered electrons is performed by multiple sensing units of the detector, the normal directions of which are tilted relative to the normal direction of the substrate.

[0068] In some aspects, the detection method includes emitting an electron beam from an electron beam source. The method includes projecting multiple electron beams onto a target region based on the electron beam using an objective lens assembly. The method also includes detecting backscattered electrons from the target region using multiple detectors located between the objective lens assembly and the target region. The multiple electron beams comprise spatially staggered and temporally distinguishable groups of electron beams.

[0069] In some embodiments, the method further includes: converting the electron beam by the objective lens group into electron beams spatially arranged based on the positions of the plurality of detectors, wherein the plurality of detectors are arranged according to a hexagonal honeycomb pattern, the groups of electron beams correspond to four groups, and at least one electron beam in each of the four groups is spatially surrounded by six electron beams in the other three groups. In some embodiments, the method further includes: converting the electron beam by the objective lens group into the groups of electron beams such that each group of electron beams begins at a different time. In some embodiments, the groups of electron beams are sequentially arranged in the time domain, with adjacent groups separated by corresponding time gaps, the groups of electron beams are sequentially arranged one group immediately following another in the time domain, or the groups of electron beams are sequentially arranged in the time domain, with adjacent groups partially overlapping in the time domain. In some embodiments, the plurality of detectors are at least 0.5 mm away from the target region. In some embodiments, the detection of a backscattered electron associated with one of the plurality of electron beams passing through an opening in the substrate of a corresponding one of the plurality of detectors is performed by a plurality of sensing units of one of the plurality of detectors, the normal directions of the plurality of sensing units being inclined relative to the normal direction of the substrate. In some embodiments, it further includes covering a side portion and a backside surface of a sensing unit of one of the plurality of detectors with at least one insulating seal, blocking at least another backscattered electron from another of the plurality of electron beams. In some embodiments, one of the plurality of electron beams passes through the opening along an axis, and each of the plurality of sensing units has a sensing surface facing the target region and inclined toward the axis.

[0070] The foregoing has outlined the features of several embodiments to enable those skilled in the art to better understand the nature of this invention. Those skilled in the art should understand that they can readily use this invention as the basis for designing or modifying other processes and structures to achieve the same purposes and / or attain the same advantages as the embodiments described herein. Those skilled in the art should also recognize that such equivalent constructions do not depart from the spirit and scope of this invention, and that various changes, substitutions, and modifications can be made to it without departing from the spirit and scope of this invention.

Claims

1. A detection device, characterized in that, include: An electron beam source, configured to emit an electron beam; The objective lens group is configured to project electron beams onto the target region based on the electron beam; as well as A detector, located between the objective lens group and the target region, and configured to detect backscattered electrons from the target region, the detector comprising: A substrate having an opening through which the electron beam passes; as well as A plurality of sensing units are disposed on the substrate and surrounding the opening, each of the plurality of sensing units having a normal direction inclined relative to the normal direction of the substrate.

2. The detection device according to claim 1, characterized in that, The substrate is divided into regions surrounding the opening, and The plurality of sensing units have a subset of sensing units, which are arranged in a rotationally symmetrical manner about the opening in the respective regions of the region.

3. The detection device according to claim 1, characterized in that, The electron beam passes through the opening along the axis, and Each of the plurality of sensing units has a sensing surface facing the target area and tilted toward the axis.

4. The detection device according to claim 1, characterized in that, Each of the plurality of sensing units includes: A sensing diode has a sensing surface at the front of the corresponding sensing unit; A signal pickup circuit is located at the rear of the corresponding sensing unit; and An insulating seal is provided to cover the sides of the corresponding sensing unit.

5. The detection device according to claim 4, characterized in that, For each of the plurality of sensing units The gap is defined between the substrate and the back surface of the signal pickup circuit of the corresponding sensing unit, and The insulating seal extends into the gap and covers the back surface of the signal pickup circuit of the corresponding sensing unit.

6. A detection device, characterized in that, include: An electron beam source, configured to emit an electron beam; The objective lens assembly is configured to project multiple electron beams onto the target region based on the electron beam; as well as Multiple detectors are located between the objective lens group and the target region, and are configured to detect backscattered electrons from the target region. The plurality of electron beams comprise groups of electron beams that are spatially interleaved and temporally distinguishable from one another.

7. The detection device according to claim 6, characterized in that, The multiple detectors are arranged in a hexagonal honeycomb pattern. The objective lens group is configured to convert the electron beam into electron beams that are spatially arranged based on the center of the hexagonal honeycomb pattern. The electron beam splitting groups correspond to four groups, and At least one electron beam from each of the four groups is spatially surrounded by six electron beams from the other three groups.

8. The detection device according to claim 6, characterized in that, The objective lens group is configured to convert the electron beam into the group of electron beams such that each of the group of electron beams begins at a different time.

9. The detection device according to claim 8, characterized in that, The electron beam splitting groups begin and end sequentially one after another, and Each of the groups of electron beams lasts for the same duration in time.

10. The detection device according to claim 8, characterized in that, The electron beams are arranged sequentially in the time domain, with adjacent groups separated by corresponding time intervals. The electron beams are arranged sequentially in the time domain, with one group immediately following another. The electron beams are arranged sequentially in the time domain, with adjacent groups partially overlapping.

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