Electron detection device and electron beam imaging apparatus

Abstract

The application discloses an electron detection device and an electron beam imaging device. The electron detection device comprises a detection assembly and an electron filtering assembly. The detection assembly comprises a plurality of detection units, each of which is in a propagation path of an electron signal. The detection units are used for receiving and processing the electron signal generated by irradiating a sample to be detected by an electron beam. The electron filtering assembly comprises a plurality of filtering units. The filtering units are used for filtering the electron signal. The plurality of filtering units are arranged in one-to-one correspondence with the plurality of detection units. In the propagation direction of the electron signal, the filtering units are located upstream of the corresponding detection units. In the plurality of filtering units, the transmittance of at least two filtering units to the electron signal is different, so that the energy spectrum bands of the electron signals passing through the at least two filtering units are different. The application can simultaneously image the electron signals of different energies with a simple structure, thereby simultaneously imaging different characteristics of the sample to be detected, and has low cost and wide application range.

Description

Technical Field

[0001] This application relates to the field of semiconductor manufacturing, and in particular to an electron detection device and an electron beam imaging device. Background Technology

[0002] Electron beam microscopy, such as scanning electron microscopy, is a commonly used method for microscopic characterization. In electron beam microscopy imaging equipment, the electron beam imaging detector (or simply electron detector) is used to receive electron signals carrying information about the sample being measured and to convert these electron signals into image signals.

[0003] In some applications, it is necessary to simultaneously image signals from different energy ranges. Current technologies primarily employ energy spectrum analyzers to deflect signals of different energy levels at different angles, directing them into different imaging channels. However, these devices are large, complex to set up, and costly, limiting their applicability. Utility Model Content

[0004] This application provides an electron detection device and an electron beam imaging device, which can simultaneously image electron signals of different energies with a simple structure, thereby simultaneously imaging different features of the sample to be tested, which helps to reduce costs and expand the scope of application.

[0005] According to a first aspect of this application, an electronic detection device is provided, comprising: a detection assembly including a plurality of detection units, each detection unit being located in the propagation path of an electronic signal, the detection units being used to receive and process electronic signals, the electronic signals being generated by irradiating a sample to be tested with an electron beam; and an electronic filtering assembly including a plurality of filtering units, the filtering units being used to filter electronic signals, the plurality of filtering units being arranged one-to-one with the plurality of detection units, the filtering units being located upstream of a corresponding detection unit in the propagation direction of the electronic signal; wherein at least two of the plurality of filtering units have different transmittances for electronic signals, so that the energy spectrum bands of the electronic signals passing through the at least two filtering units are different.

[0006] In some embodiments, the filter unit includes two or more filter elements spaced apart in the direction of electronic signal propagation. Each filter element includes multiple vias. In the same projection plane perpendicular to the propagation direction, the orthographic projections of the corresponding vias of the two or more filter elements at least partially overlap. One of the two or more filter elements is connected to a power source and forms a potential difference with the other filter elements. The potential differences of at least two filter elements are different, so that the transmittance of the electronic signal by the at least two filter elements is different.

[0007] In some embodiments, two or more filter components include a first filter component and a second filter component. In the propagation direction, the first filter component is located upstream of the second filter component. The first filter component is grounded, and the second filter component is connected to a power source and forms a potential difference with the first filter component.

[0008] In some embodiments, the plurality of vias of the first filter element includes a plurality of first vias, and the plurality of vias of the second filter element includes a plurality of second vias; one of the first filter element and the second filter element is configured to be movably disposed relative to the other to adjust the area of ​​the overlapping region of the respective first vias and second vias, thereby adjusting the amount of electronic signal passing through the filter unit.

[0009] In some embodiments, at least a portion of the filter element is a filter made of graphite or graphene.

[0010] In some embodiments, a plurality of detection units are arranged along the outer periphery of a reference axis, and a plurality of filtering units are arranged along the outer periphery of the reference axis, the reference axis being parallel to the propagation direction.

[0011] In some embodiments, the electron detection device includes a shielding member, the interior of which defines a shielding cavity for the passage of an electron beam, and a reference axis parallel to the central axis of the shielding cavity; a plurality of detection units are arranged along the outer periphery of the shielding member, and a plurality of filtering units are arranged along the outer periphery of the shielding member.

[0012] In some embodiments, the reference axis is the central axis of the shielding cavity, and the distance between the multiple detection units and the reference axis is the same along the radial direction of the shielding component.

[0013] In some embodiments, there are two detection units and two filtering units, and the two detection units are arranged symmetrically about the reference axis; or, there are four detection units and four filtering units, and the four detection units are distributed at equal intervals along the outer periphery of the reference axis. Along the circumference of the reference axis, the transmittance of electronic signals is different for two adjacent filtering units, and the transmittance of electronic signals is the same for two non-adjacent filtering units.

[0014] According to a second aspect of this application, an electron beam imaging device is provided, comprising: an electron beam source for emitting an electron beam toward a sample; and an electron detection device according to any embodiment of the first aspect, wherein the electron detection device is used to receive an electronic signal generated by the electron beam irradiating the sample under test, and convert the electronic signal into an image signal.

[0015] The electron detection device provided in this application embodiment simultaneously sets up multiple detection units in the propagation path of the electron signal. Each detection unit has a corresponding filter unit upstream. At least two filter units have different transmittance for the electron signal, resulting in different energy spectrum bands of the electron signals transmitted to the at least two detection units. These at least two detection units can simultaneously process electron signals of different energy spectrum bands, which is beneficial for simultaneously imaging electron signals of different energies, thereby enabling simultaneous imaging of different features of the sample under test (e.g., surface morphology, composition, etc.). The electron detection device provided in this application embodiment has a relatively simple structure and setup, low cost, and wide applicability, especially suitable for laboratory, industrial, or other application scenarios where high energy resolution accuracy is not required. Attached Figure Description

[0016] The features, advantages, and technical effects of exemplary embodiments of this application will now be described with reference to the accompanying drawings.

[0017] Figure 1 This is a schematic diagram of the structure of an electronic detection device provided in some embodiments of this application;

[0018] Figure 2 This is one of the cross-sectional views of the electronic detection device provided in other embodiments of this application;

[0019] Figure 3 This is another cross-sectional view of the electronic detection device provided in some other embodiments of this application;

[0020] Figure 4 This is a schematic diagram of the structure of a filtering unit provided in some embodiments of this application;

[0021] Figure 5 This is a schematic diagram of the structure of an electron beam imaging device provided in some embodiments of this application.

[0022] The reference numerals in the accompanying drawings for the specific embodiments are as follows:

[0023] 1. Electron detection device; 3. Electron beam imaging equipment; 4. Electron beam source; 2. Sample to be tested;

[0024] Detection component 10, detection unit 11, scintillator 111, light guide 112, photomultiplier tube 113;

[0025] Electronic filter assembly 20, filter unit 21, signal channel 211, first filter component 212, first via 2121, second filter component 213, second via 2131;

[0026] Shielding component 40, shielding cavity 41;

[0027] Power supply 30, reference axis a, propagation direction X. Detailed Implementation

[0028] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly described below with reference to the accompanying drawings. Obviously, the described embodiments are some embodiments of this application, but not all embodiments.

[0029] The terms "first," "second," "third," etc., used in the specification, claims, or accompanying drawings of this application are used to distinguish different objects, not to describe a specific order or hierarchy. In the embodiments of this application, the same reference numerals denote the same components, and for the sake of brevity, detailed descriptions of the same components are omitted in different embodiments.

[0030] In this application, the reference to "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places in the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment that is mutually exclusive with other embodiments.

[0031] In the description of this application, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0032] In the embodiments of this application, "parallel" includes not only the case of absolute parallelism, but also the case of approximate parallelism as commonly understood in engineering; similarly, "perpendicular" also includes not only the case of absolute perpendicularity, but also the case of approximate perpendicularity as commonly understood in engineering. For example, if the angle between two directions is 85°-95°, the two directions can be considered perpendicular; if the angle between two directions is 0°-10°, the two directions can be considered parallel.

[0033] Figure 1 This is a schematic diagram of the structure of an electronic detection device provided in some embodiments of this application. Figure 2 This is one of the cross-sectional views of the electronic detection device provided in other embodiments of this application. Figure 3 This is another cross-sectional view of the electronic detection device provided in other embodiments of this application. (Refer to...) Figures 1 to 3The electron detection device 1 provided in this application embodiment includes a detection component 10 and an electron filtering component 20. The detection component 10 includes multiple detection units 11, each located within the propagation path of the electron signal. The detection units 11 are used to receive and process the electron signal, which is generated by irradiating the sample 2 under test with an electron beam. The electron filtering component 20 includes multiple filtering units 21, which are used to filter the electron signal. The multiple filtering units 21 are arranged in a one-to-one correspondence with the multiple detection units 11, and in the propagation direction X of the electron signal, the filtering unit 21 is located upstream of a corresponding detection unit 11. Among the multiple filtering units 21, at least two filtering units 21 have different transmittance for the electron signal, so that the energy spectrum bands of the electron signals passing through at least two filtering units 21 are different.

[0034] The sample to be tested includes, but is not limited to, wafers. The electron signal generated by the electron beam irradiation of the sample to be tested 2 mainly includes secondary electrons and backscattered electrons. Secondary electrons mainly carry information such as the surface morphology of the sample to be tested 2, while backscattered electrons have a higher depth and mainly carry information such as the composition and density of the sample to be tested 2.

[0035] In this embodiment, the propagation direction X of the electronic signal refers to the direction in which the main part of the electronic signal is emitted from the sample 2 to the detector component 10. This direction is usually perpendicular to the surface of the sample 2 and parallel to the optical axis of the electron beam.

[0036] The detection unit 11 is used to detect sample feature information carried by electronic signals. Optionally, the detection unit 11 includes a scintillator 111, a light guide 112, and a photomultiplier tube 113. The scintillator 111 is used to receive electronic signals and convert them into light signals. The light guide 112 is used to conduct the light signals generated by the scintillator 111 to the photomultiplier tube 113. The photomultiplier tube 113 is used to convert the light signals conducted by the light guide 112 into electrical signals for imaging.

[0037] Each detection unit 11 is located within the propagation path of the electronic signal. In other words, within the same projection plane perpendicular to the propagation direction X of the electronic signal, the orthographic projections of the multiple detection units 11 do not overlap. The reception of the electronic signal by the multiple detection units 11 does not affect each other.

[0038] Along the propagation direction X of the electronic signal, the spacing between the multiple detection units 11 and the measured surface of the sample 2 can be the same or different. Optionally, the spacing between the multiple detection units 11 and the measured surface of the sample 2 can be the same to reduce the influence of this spacing on the detection results.

[0039] The transmittance of the filter unit 21 for electronic signals refers to the ability of the filter unit 21 to transmit electronic signals within the same energy spectrum band. At least two filter units 21 have different transmittance capabilities for electronic signals within the same energy spectrum band. For example, one filter unit 21 may have a weaker transmittance capability for electronic signals within a preset energy spectrum band than the other filter unit 21.

[0040] In the propagation path of the electronic signal, a filter unit 21 is located between a corresponding detector unit 11 and the sample 2 to filter the electronic signal emitted from the sample 2 to the detector unit 11. Each filter unit 21 has a preset transmittance for the electronic signal, thereby allowing the target electronic signal of a preset energy spectrum band to be transmitted to the corresponding detector unit 11. The energy spectrum band of the electronic signal passing through each filter unit 21 is related to the transmittance of the electronic signal by that filter unit 21.

[0041] The difference in transmittance of electronic signals between at least two filter units 21 can be achieved in a variety of ways. For example, filter unit 21 may include a bias filter, where a voltage difference applied to the bias filter results in different transmittances of electronic signals between the different filter units 21. For example, the difference in transmittance of electronic signals between the different filter units 21 may also be achieved through differences in the materials used in the different filter units 21 themselves.

[0042] The electron detection device 1 provided in this application embodiment simultaneously arranges multiple detection units 11 in the propagation path of the electron signal. Each detection unit 11 is equipped with a corresponding filter unit 21 upstream. At least two filter units 21 have different transmittance for the electron signal, so that the energy spectrum of the electron signal transmitted to the at least two detection units 11 is different. The at least two detection units 11 can process the received electron signals of different energy spectrums simultaneously, which is beneficial for simultaneous imaging of electron signals of different energies, thereby enabling simultaneous imaging of different features (such as surface morphology, composition, etc.) of the sample 2 under test.

[0043] For example, the electronic signal includes secondary electrons. Secondary electrons typically have low energy, generally less than 50 eV (electron volts), and the sampling depth is generally less than 10 nm. By setting the transmittance of at least one filter unit 21, only secondary electrons that conform to the corresponding energy spectrum can pass through the at least one filter unit 21, and at least one detection unit 11 corresponding to the at least one filter unit 21 can image the morphological features of the surface of the sample 2 under test based on the secondary electrons it receives.

[0044] For example, the electronic signal includes backscattered electrons. The energy of the backscattered electrons is almost the same as that of the high-energy incident electron beam, typically in the kiloelectron volt range, and the sampling depth is typically one-third the thickness of the sample 2 under test. By setting the transmittance of at least one filter unit 21, only backscattered electrons that conform to the corresponding energy spectrum can pass through the at least one filter unit 21. At least one detection unit 11 corresponding to the at least one filter unit 21 can image the internal morphology, composition, and other information of the sample 2 under test based on the backscattered electrons it receives.

[0045] The electronic detection device 1 provided in this application embodiment achieves the purpose of simultaneously imaging electronic signals of different energies by using the difference in transmittance of electronic signals through different filter units 21. The structure and setting method are relatively simple, the cost is low, and the application range is wide. It is especially suitable for laboratories, industries or other application scenarios where the energy resolution accuracy requirements are not high.

[0046] Figure 4 This is a schematic diagram of the structure of a filtering unit provided in some embodiments of this application. (Refer to...) Figure 1 and Figure 4 In some embodiments, the filter unit 21 includes two or more filter elements spaced apart along the propagation direction X of the electronic signal, each filter element including multiple vias. In the same projection plane perpendicular to the propagation direction X, the orthographic projections of corresponding vias of the two or more filter elements at least partially overlap. One of the two or more filter elements is connected to the power supply 30 and forms a potential difference with the remaining filter elements. The potential difference between at least two filter units is different, such that the transmittance of the electronic signal by the at least two filter units is different.

[0047] The vias penetrate the filter components along the propagation direction X of the electronic signal. The vias in each filter component allow the electronic signal to pass through, while other parts of the filter component, excluding the vias, can block the electronic signal. Each filter component filters the electronic signal. The electronic signal passing through all the filter components is transmitted to the detection unit 11.

[0048] The orifices of two or more filter components can be set in a one-to-one correspondence or in a many-to-one correspondence.

[0049] Optionally, two or more filter elements are matched in shape, and the distribution of multiple through holes in each filter element is similar, so that the multiple through holes of the two or more filter elements are set in a corresponding manner.

[0050] The filter unit 21 may include a plurality of signal channels 211 for passing electronic signals. Each signal channel 211 includes an overlapping portion of corresponding vias of two or more filter components along the propagation direction X of the electronic signal, and a gap between two adjacent filter components corresponding to the overlapping portion.

[0051] One of the two or more filter components is connected to the power supply 30, which applies a bias voltage to the filter component. This filter component can serve as the bias electrode of the filter unit 21. Among the two or more filter components, all of them except the bias electrode can be grounded and serve as the ground electrode of the filter unit 21. This can create a potential difference between the bias electrode and the ground electrode, simplify the structure, and reduce costs.

[0052] Optionally, in at least two filter units 21, the bias voltages applied to the filter components, which serve as bias electrodes, are different, so that the potential difference between the at least two filter units 21 is different. The voltage applied to the filter components can be determined based on the energy spectrum curve of the electron signal corresponding to the yield of the sample 2 to be tested.

[0053] The potential difference of the filter unit 21 affects the transmittance of the filter unit 21 to the electronic signal, so as to selectively filter the electronic signal in a preset energy spectrum range. For example, for electronic signals with an energy distribution range of 5keV-10keV, if a voltage of -6kV is applied to the filter component of one of the filter units 21 as a bias electrode, electronic signals with energy below 6keV can be effectively filtered, so that the detection unit 11 corresponding to the filter unit 21 can selectively receive and process electronic signals with energy in the range of 6keV-10keV.

[0054] This application embodiment sets up two or more filter components in the filter unit 21 and applies a bias voltage to one of the filter components. By the difference in the bias voltage of at least two filter units 21, the transmittance of at least two filter units 21 for electronic signals is different. This not only simplifies the structure, but also makes it easy to select and adjust the bias voltage, which is beneficial for flexibly adjusting the energy spectrum of the electronic signal that needs to be imaged, and meeting a variety of different user needs.

[0055] In some embodiments, the two or more filter components include a first filter component 212 and a second filter component 213. In the direction of electronic signal propagation X, the first filter component 212 is located upstream of the second filter component 213. The first filter component 212 is grounded, and the second filter component 213 is connected to the power supply 30 and forms a potential difference with the first filter component 212.

[0056] The second filter element 213 is closer to the detection unit 11 than the first filter element 212. Part of the electronic signal generated by the electron beam irradiating the sample 2 first passes through the first filter element 212 and then through the second filter element 213.

[0057] Optionally, the first filter element 212 can be the filter element closest to the sample 2 in the filter unit 21.

[0058] In the direction of electronic signal propagation X, the second filter element 213 is located downstream of the first filter element 212. The second filter element 213 is located on the side of the first filter element 212 away from the sample 2, and is further away from the sample 2 than the first filter element 212. By applying a bias voltage to the second filter element 213, the first filter element 212 can appropriately shield the electric field around the second filter element 213, which helps to reduce the interference and influence of the electric field on the electronic signal.

[0059] In some embodiments, the plurality of vias of the first filter element 212 includes a plurality of first vias 2121, and the plurality of vias of the second filter element 213 includes a plurality of second vias 2131. One of the first filter element 212 and the second filter element 213 is configured to be movably disposed relative to the other to adjust the area of ​​the overlapping region of the first vias 2121 and the second vias 2131, thereby adjusting the amount of electronic signal passing through the filter unit 21.

[0060] The overlapping area of ​​the first via 2121 and the second via 2131 refers to the area corresponding to the overlapping portion of the orthographic projection of the first via 2121 and the orthographic projection of the second via 2131 within the same projection plane perpendicular to the propagation direction X of the electronic signal.

[0061] In some examples, the first filter element 212 is fixedly set, while the second filter element 213 is movable, so that the overlapping area of ​​the corresponding first through hole 2121 and second through hole 2131 can be adjusted by the movement of the second filter element 213, which helps to simplify the structure and reduce the difficulty of adjustment.

[0062] In other examples, the second filter element 213 is fixedly installed, while the first filter element 212 is movable. This allows for adjustment of the overlapping area of ​​the corresponding first through-hole 2121 and second through-hole 2131 through the movement of the first filter element 212, which simplifies the structure and reduces the difficulty of adjustment.

[0063] In some other examples, both the first filter element 212 and the second filter element 213 can be movably configured, which helps to expand the adjustable range within the limited range of motion of the first filter element 212 and the second filter element 213.

[0064] In this embodiment, the first filter element 212 and the second filter element 213 are configured to be relatively movable, which is beneficial for adjusting the amount of electronic signal transmitted through the filter element 21 to the corresponding detection unit 11, thereby enabling the filter element 21 to adapt to various types of detection units 11, and also helps to protect the detection unit 11 and reduce its risk of damage.

[0065] In some embodiments, the electronic detection device 1 includes a drive mechanism connected to at least one of the first filter component 212 and the second filter component 213. The drive mechanism is used to drive one of the first filter component 212 and the second filter component 213 to move relative to the other, so as to adjust the area of ​​the overlapping region of the corresponding first through hole 2121 and the second through hole 2131.

[0066] In some embodiments, at least a portion of the filter element is a filter screen made of graphite or graphene. The filter element is made of graphite or graphene, which has a near-zero secondary electron yield, which helps to reduce the secondary electrons generated by the filter element and reduce the impact on the detection results of the filter element electron detection device 1.

[0067] In some embodiments, the first filter element 212 is a filter screen made of graphite or graphene.

[0068] In some embodiments, the second filter element 213 is a filter made of graphite or graphene.

[0069] In some embodiments, refer to Figures 1 to 3 Multiple detection units 11 and multiple filter units 21 are arranged along the outer periphery of a reference axis a. The reference axis a is parallel to the propagation direction X of the electronic signal. Optionally, the reference axis a is perpendicular to the surface of the sample 2 under test.

[0070] Multiple detection units 11 can be uniformly distributed along the outer periphery of the reference axis a, or they can be non-uniformly distributed. For example, multiple detection units 11 can be distributed within a set arc range around the reference axis a.

[0071] Multiple detection units 11 can be distributed at equal intervals along the outer periphery of the reference axis a, or they can be distributed at non-equal intervals.

[0072] Along the direction of electronic signal propagation X, the filter units 21 can be spaced apart on the side of a corresponding detector unit 11 near the sample 2 to be tested. The distribution of the multiple filter units 21 corresponds to the distribution of the multiple detector units 11, which will not be described in detail here.

[0073] The electronic detection device 1 can form a gap at the position corresponding to the reference axis a. This gap can be used to allow the electron beam to pass through, which helps to reduce the interference and influence of the electronic detection device 1 on the electron beam.

[0074] Multiple detection units 11 distributed along the outer periphery of the reference axis a can receive electronic signals from different angles, thereby imaging the sample 2 under test from different angles, which is beneficial to expanding the imaging range of the electronic detection device 1.

[0075] In some embodiments, refer to Figures 1 to 3 The electron detection device 1 includes a shield 40, the interior of which defines a shielding cavity 41 for the passage of an electron beam, and a reference axis a parallel to the central axis of the shield 40. Multiple detection units 11 and multiple filtering units 21 are arranged along the outer periphery of the shield 40.

[0076] The shielding element 40 is used to shield the electric field, which can be the electric field generated after applying a bias voltage to the filter element, or an external electric field, etc., to reduce the influence of the electric field on the focusing or deflection of the electron beam and reduce interference to the electron beam.

[0077] Optionally, the shielding element 40 is a conductive component to improve the shielding effect. For example, the shielding element 40 is made of metal.

[0078] The shielding cavity 41 penetrates the shielding member 40 along the propagation direction X of the electronic signal, so that the electron beam can pass through the shielding member 40 along the propagation direction X.

[0079] Optionally, the reference axis a passes through the shielding cavity 41 along the propagation direction X of the electronic signal. The reference axis a may or may not coincide with the central axis of the shielding component 40.

[0080] Multiple detection units 11 and multiple filter units 21 are located radially outside the shield 40, which helps to improve the shielding effect of the shield 40 and reduce the interference of the detection units 11 and filter units 21 on the electron beam.

[0081] In some embodiments, the reference axis a is the central axis of the shielding cavity 41, and the distance between the plurality of detection units 11 and the reference axis a is the same along the radial direction of the shielding member 40.

[0082] The shielding component 40 is a hollow cylinder, and the shielding cavity 41 can be a cylindrical cavity.

[0083] Optionally, the multiple filter units 21 are spaced at the same distance from the reference axis a.

[0084] The equal spacing between multiple detection units 11 and the reference axis a facilitates a more symmetrical coverage of the main area of ​​each detection unit 11 by the beam spot of the electronic signal, thereby improving the capture efficiency of each detection unit 11 for the electronic signal.

[0085] In some embodiments, refer to Figure 1There are two detector units 11 and two filter units 21, with the two detector units 11 arranged centrally symmetrically about the reference axis a. Optionally, the two filter units 21 are also arranged centrally symmetrically about the reference axis a. The two filter units 21 have different transmittance for electronic signals, and the energy spectrum of the electronic signals transmitted to the two detector units 11 through the two filter units 21 is different, which is beneficial for achieving simultaneous imaging of electronic signals of different energy spectrums with a simple structure.

[0086] In some embodiments, refer to Figure 2 and Figure 3 There are four detection units 11 and four filter units 21. The four detection units 11 are evenly spaced along the outer periphery of the reference axis a. Along the circumference of the reference axis a, the transmittance of two adjacent filter units 21 to the electronic signal is different, while the transmittance of two non-adjacent filter units 21 to the electronic signal is the same.

[0087] Optionally, each detection unit 11 has a receiving surface for receiving electronic signals. The receiving surface of each detection unit 11 and each filter unit 21 are approximately fan-shaped, which is beneficial to increase the area of ​​each detection unit 11 and each filter unit 21 and improve the electronic signal capture efficiency.

[0088] Optionally, in two adjacent filter units 21, the voltage applied to the filter component, which serves as a bias electrode, is different, so that the transmittance of the two adjacent filter units 21 for electronic signals is different. Two adjacent detection units 11 can be used to acquire image information of different features of the sample 2 under test at the same viewing angle.

[0089] Optionally, in two non-adjacent filter units 21, the voltage applied to the filter component, which serves as a bias electrode, is the same, so that the transmittance of the two non-adjacent filter units 21 for electronic signals is the same. The two non-adjacent detection units 11 correspond to different viewing angles of the sample 2 under test, and can be used to acquire image information of the same feature of the sample 2 under opposite viewing angles.

[0090] For example, two adjacent detection units 11 can be used to receive secondary electrons and backscattered electrons, respectively, to acquire a 0° angle image of the morphology of the sample to be tested and a 90° angle image of the components of the sample to be tested, respectively. Two other adjacent detection units 11 can be used to receive secondary electrons and backscattered electrons, respectively, to acquire a 180° angle image of the morphology of the sample to be tested and a 270° angle image of the components of the sample to be tested, respectively.

[0091] Detection units 11 located at different angles, with corresponding filter units 21 having the same transmittance for electronic signals, can receive and identify electronic signals from different angles within the same energy spectrum band, thereby identifying sample information with the same features from different perspectives. Detection units 11 located at different angles, with corresponding filter units 21 having different transmittance for electronic signals, can receive and identify electronic signals from different angles and different energy spectrum bands, thereby identifying sample information with different perspectives and features. The embodiments of this application facilitate the realization of hybrid imaging functions of electronic signal energy resolution and angle resolution, making it easier to provide a multi-dimensional feature characterization method for the sample 2 under test.

[0092] According to a second aspect of this application, embodiments of this application also provide an electron beam imaging device for detecting wafer surface defects or critical dimensions.

[0093] Figure 5 This is a schematic diagram of the structure of an electron beam imaging device provided in some embodiments of this application. The electron beam imaging device 3 provided in the embodiments of this application includes an electron beam source 4 and an electron detection device 1 provided in any embodiment of this application. The electron beam source 4 is used to emit an electron beam toward the sample 2 under test (e.g., a wafer). The electron detection device 1 is used to receive the electron signal generated by the electron beam irradiating the sample 2 under test and convert the electron signal into an image signal.

[0094] The electron beam imaging device 3 of this application embodiment can simultaneously image electron signals of different energies through the electron detection device 1, thereby simultaneously imaging different features (such as surface morphology, composition, etc.) of the sample 2 under test. Furthermore, the electron beam imaging device 3 has a relatively simple structure and setting method, and low cost, making it particularly suitable for laboratory, industrial, or other application scenarios where high energy resolution accuracy is not required.

[0095] Electron beam imaging equipment 3 includes, but is not limited to, scanning electron microscopes, transmission electron microscopes, electron beam exposure systems, etc.

[0096] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and not to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. These modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application, and they should all be covered within the scope of the claims and specification of this application. In particular, as long as there is no structural conflict, the various technical features mentioned in the embodiments can be combined in any way. This application is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of the claims.

Claims

1. An electronic detection device, characterized in that, include: A detection assembly includes multiple detection units, each positioned within the propagation path of an electronic signal. Each detection unit receives and processes the electronic signal, which is generated by an electron beam irradiating a sample. An electronic filtering assembly includes multiple filtering units for filtering the electronic signal. The multiple filtering units are arranged in a one-to-one correspondence with multiple detection units. In the direction of propagation of the electronic signal, the filtering unit is located upstream of a corresponding detection unit. Of the plurality of filter units, at least two filter units have different transmittance for the electronic signal, such that the energy spectrum of the electronic signal passing through the at least two filter units is different.

2. The electronic detection device according to claim 1, characterized in that, The filtering unit includes two or more filtering components spaced apart in the direction of propagation of the electronic signal. Each filtering component includes multiple vias. In the same projection plane perpendicular to the direction of propagation, the orthographic projections of the corresponding vias of the two or more filtering components at least partially overlap. One of the two or more filter elements is connected to a power source and forms a potential difference with the other filter elements. The potential differences of at least two filter elements are different, so that the transmittance of the electronic signal is different for at least two filter elements.

3. The electronic detection device according to claim 2, characterized in that, The two or more filter components include a first filter component and a second filter component. In the propagation direction, the first filter component is located upstream of the second filter component. The first filter component is grounded, and the second filter component is connected to the power supply and forms a potential difference with the first filter component.

4. The electronic detection device according to claim 3, characterized in that, The plurality of through holes in the first filter component includes a plurality of first through holes, and the plurality of through holes in the second filter component includes a plurality of second through holes; One of the first filter element and the second filter element is configured to be movable relative to the other to adjust the area of ​​the overlapping region of the corresponding first and second vias, thereby adjusting the amount of electronic signal passing through the filter unit.

5. The electronic detection device according to claim 2, characterized in that, At least a portion of the filter components are filters made of graphite or graphene.

6. The electronic detection device according to claim 1, characterized in that, The plurality of detection units are arranged along the outer periphery of a reference axis, and the plurality of filtering units are arranged along the outer periphery of the reference axis, which is parallel to the propagation direction.

7. The electronic detection device according to claim 6, characterized in that, The electron detection device includes a shielding component, the interior of which defines a shielding cavity for the passage of an electron beam, and the reference axis is parallel to the central axis of the shielding cavity; The plurality of detection units are arranged along the outer periphery of the shield, and the plurality of filtering units are arranged along the outer periphery of the shield.

8. The electronic detection device according to claim 7, characterized in that, The reference axis is the central axis of the shielding cavity, and the distance between the plurality of detection units and the reference axis is the same along the radial direction of the shielding component.

9. The electronic detection device according to claim 6, characterized in that, There are two detection units and two filtering units, and the two detection units are arranged symmetrically about the reference axis; or There are four detection units and four filtering units. The four detection units are evenly spaced along the outer periphery of the reference axis. Along the circumference of the reference axis, the transmittance of two adjacent filtering units to the electronic signal is different, and the transmittance of two non-adjacent filtering units to the electronic signal is the same.

10. An electron beam imaging device, characterized in that, include: An electron beam source, used to emit an electron beam toward a sample; as well as According to any one of claims 1-9, the electronic detection device is used to receive the electronic signal generated by the electron beam irradiating the sample to be tested, and convert the electronic signal into an image signal.

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