Signal electron beam deflector for electron beam device, electron beam device and method for deflecting signal electron beam

Abstract

A signal electron beam deflector for an electron beam device is provided. A signal electron beam deflector includes a first electrode extending in a curved manner and a second electrode extending in a curved manner and having at least one electronically transparent portion configured for passing a signal electron beam through the at least one electronically transparent portion. The first electrode and the second electrode are arranged adjacent to each other to form a space therebetween. The space has an inlet opening and an outlet opening; providing a first optical path between the inlet opening and the outlet opening; and providing a second optical path between the entrance opening and the at least one electronically transparent portion of the second electrode.

Description

Technical Field

[0001] Embodiments of the present disclosure relate to electron beam devices, for example, for inspection system applications, test system applications, lithography system applications, defect review, critical dimension applications, and the like. In particular, embodiments of the present disclosure relate to a signal electron beam deflector for an electron beam device. Embodiments of the present disclosure particularly relate to a signal electron beam deflector for an electron beam device, an electron beam device, and a method of deflecting a signal electron beam. Background Art

[0002] Modern semiconductor technology places high demands on structuring and probing samples at the nano- or even sub-nano scale. Process control, inspection, or structuring at the micro- and nano-scale is often accomplished using an electron beam, which is generated, shaped, deflected, and focused in an electron beam device such as an electron microscope or an electron beam pattern generator. For inspection purposes, charged electron beams offer excellent spatial resolution compared to, for example, photon beams.

[0003] Devices using electron beams, such as scanning electron microscopes (SEM), have many functions in a number of industrial fields, including but not limited to the inspection of electronic circuits, exposure systems for lithography, detection systems, defect inspection tools, and test systems for integrated circuits. In such an electron beam system, a fine beam probe with a high current density can be used. For example, in the case of an SEM, the primary electron beam generates signal electrons, such as secondary electrons (SE) and / or backscattered electrons, when hitting the sample, and the signal electrons can be used for imaging and / or inspecting the sample.

[0004] In a scanning electron microscope (SEM), it is advantageous to detect BSE from the sample with high efficiency. The choice of the emission angle and energy of the BSE can contain information about the sample. There is a trend in SEMs to use higher acceleration energies, even up to 100 keV, which means that the BSE also has high energy. At the same time, it is beneficial to detect SE. Sometimes, it is beneficial to distinguish between the emission azimuth angles, for example, in order to obtain topographical contrast.

[0005] Electron beam devices can have different detection optics. Some electron beam devices are equipped with segmented detectors, such as quadrant SE detectors. For example, an in-lens detector (ILD) can be provided on the optical axis, for example, between the objective lens and the beam splitter. Some electron beam devices deflect signal electrons onto a secondary optical axis at a large angle (e.g., 60° or greater), where the energy can be filtered.

[0006] In view of the above, it would be beneficial to implement improved devices and methods for simultaneously measuring fast BSE and SE generated, for example, at higher acceleration energies (e.g., up to 100 keV). Embodiments of the present disclosure are directed to providing a signal electron beam deflector for an electron beam device, an electron beam device, and a method for deflecting a signal electron beam. SUMMARY OF THE INVENTION

[0007] In view of the above, a signal electron beam deflector for an electron beam device, an electron beam device, and a method for deflecting a signal electron beam are provided. Further aspects, advantages, and features of the present disclosure are apparent from the claims, the specification, and the drawings.

[0008] According to one aspect, a signal electron beam deflector for an electron beam device is provided. The signal electron beam deflector includes a first electrode extending in a curved manner and a second electrode extending in a curved manner and having at least one electron-transparent portion. The first electrode and the second electrode are arranged adjacent to each other to form a space between the first electrode and the second electrode such that: the space has an inlet opening and an outlet opening, a first optical path is provided between the inlet opening and the outlet opening, and a second optical path is provided between the inlet opening and at least one electron-transparent portion of the second electrode.

[0009] According to one aspect, a signal electron beam deflector for an electron beam device is provided. The signal electron beam deflector includes a first electrode and a second electrode that provide a first optical path therebetween, and at least one electron-transparent portion provided in the second electrode. A second optical path is provided, the second optical path passing through the at least one electron-transparent portion, and the signal electron beam deflector is configured to guide electrons of the signal electron beam along the first optical path and along the second optical path according to the energy of the electrons of the signal electron beam.

[0010] According to one aspect, an electron beam device is provided. According to embodiments described herein, the electron beam device includes a sample stage, a deflector system, an electron source adapted to generate a primary electron beam, and a signal electron beam deflector.

[0011] According to one aspect, a method for deflecting a signal electron beam is provided. The method includes: guiding a signal electron beam from a sample to a signal electron beam deflector having a first electrode and a second electrode; guiding slow electrons of the signal electron beam along a first optical path provided between an inlet opening and an outlet opening of the signal electron beam deflector; and guiding fast electrons of the signal electron beam along a second optical path provided between the inlet opening and at least one electron-transparent portion provided in the second electrode of the signal electron beam deflector. Further advantages, features, aspects, and details that can be combined with the embodiments described herein are apparent from the dependent claims, the specification, and the drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Accordingly, in order to be able to understand in detail the manner in which the above-described features of the present disclosure are used, a more specific description of the present disclosure briefly outlined above may be referred to the embodiments. The drawings relate to embodiments of the present disclosure and are described as follows:

[0013] Figure 1 Schematic diagram of a signal electron beam deflector according to an embodiment described herein;

[0014] Figure 2A Schematic diagram of a signal electron beam deflector according to an embodiment described herein, wherein the second electrode is provided as an electron transparent grid;

[0015] Figure 2B Schematic diagram of a signal electron beam deflector according to an embodiment described herein, wherein the second electrode is provided as an electron transparent foil.

[0016] Figures 3A to 3C Schematic cross-sectional view of the first and second electrodes of a signal electron beam deflector according to an embodiment described herein;

[0017] Figure 4 Schematic diagram of an electron beam device having a signal electron beam deflector according to an embodiment described herein;

[0018] Figure 5 Flowchart of a method for deflecting a signal electron beam according to an embodiment described herein. DETAILED DESCRIPTION

[0019] Reference will now be made in detail to various embodiments of the present disclosure, one or more examples of which are illustrated in the drawings. In the following description of the drawings, like reference numerals refer to like components. In general, only the differences relative to individual embodiments are described. Each example is provided by way of explanation of the present disclosure, and not intended as a limitation of the present disclosure. Additionally, features shown or described as part of one embodiment may be used in other embodiments or combined with other embodiments to yield additional embodiments. The description is intended to include such modifications and variations.

[0020] In an electron beam apparatus, a signal electron beam can be emitted from a sample by impinging a primary electron beam on the sample. The signal electron beam can be detected to obtain information about the sample, such as imaging of the sample. A signal electron beam deflector can deflect the signal electron beam. For example, the signal electron beam deflector can deflect the signal electron beam to direct the signal electron beam to a detector. The signal electron beam deflector can include electrodes configured to deflect the signal electron beam, such as a first electrode and a second electrode. The signal electron beam can be directed along an optical path towards the detector, such as along a first optical path provided in a space between the first electrode and the second electrode.

[0021] The resolution and / or throughput of the electron beam apparatus can be improved by detecting all or most of the electrons. The signal electron beam can be directed to the detector, such as along the first optical path, by the signal electron beam deflector. Some electrons of the signal electron beam (such as fast BSE) may have too high an energy to be deflected along the first optical path. The signal electron beam deflector of the present disclosure has at least one electron-transparent portion in the second electrode. The at least one electron-transparent portion provided in the second electrode provides a second optical path. The fast BSE can be deflected along the second optical path. Advantageously, the fast BSE can leave the signal electron beam deflector through the at least one electron-transparent portion and can be directed to the detector. In some embodiments, the at least one electron-transparent portion includes a beam opening provided in the second electrode. The beam opening can be a slit provided in the second electrode. An electron-transparent grid or an electron-transparent foil can be provided to at least partially overlap the beam opening.

[0022] In some embodiments, the at least one electron-transparent portion includes an electron-transparent grid or an electron-transparent foil. The grid or foil is highly transparent to signal electrons (especially BSE) and allows the signal electrons to pass through the grid or foil while the potential distribution in the signal electron beam deflector is substantially undisturbed. The at least one electron-transparent portion (including, for example, the electron-transparent grid or foil) can allow the BSE to be transmitted to the detector above. Advantageously, the signal electron beam deflector of the present application provides a higher detection efficiency for fast BSE. The higher detection efficiency of fast BSE increases the throughput of the electron beam apparatus of the present disclosure and / or an electron beam apparatus having a signal electron beam deflector according to the embodiments described herein. Advantageously, the signal electron beam deflector allows simultaneous detection of BSE and SE. The combination of BSE and SE detection provides better contrast for the features detected using the electron beam apparatus.

[0023] Backscattered electrons and secondary electrons may be deflected away from the optical path of the primary electrons, e.g., deflected to be directed to a detector. A signal electron beam deflector may be limited to certain energy bands of electrons that can be deflected simultaneously. The signal electron beam deflector according to the present disclosure allows for the simultaneous detection of fast BSEs with energies up to 20 keV, and even up to 100 keV (after release from the sample), and slow BSEs and SEs with energies down to a few eV (after release from the sample) by creating an exit path for the fast BSEs. The signal electron beam deflector according to the present disclosure allows for the simultaneous detection of BSEs (e.g., for depth information) and SEs (e.g., for surface information), particularly both with high acquisition efficiency. For fast BSE detection and SE detection, the electron beam device may have an in-lens SE detector with an opening for the fast BSEs. This limits the BSE signal and thus the throughput of the electron beam device. The signal electron beam deflector according to the present disclosure allows for the removal of the in-lens SE detector. The BSE signal and throughput can be increased.

[0024] Throughout this application and if not otherwise indicated, electrons are referred to as follows depending on their energy. Electrons having an energy of less than 100 eV or less than 1 keV after the emission of the signal electron beam from the sample are referred to as slow electrons; and electrons having an energy of greater than 1 keV after the emission of the signal electron beam from the sample are referred to as fast electrons. Additionally, in some embodiments, an acceleration energy may be provided to the signal electron beam. Fast electrons and slow electrons may be accelerated by a voltage that increases the energy of the slow electrons and fast electrons by a value corresponding to the voltage (i.e., the same voltage). The acceleration energy may correspond to an acceleration voltage V a . The acceleration voltage may be up to 10 kV, particularly up to 30 kV or even higher. The acceleration energy may be up to 10 keV, particularly up to 30 keV or even higher. Electrons to which the acceleration energy is provided and having an energy of less than the acceleration energy + 100 eV or less than the acceleration energy + 1 keV are referred to as slow electrons within the deflector; electrons to which the acceleration energy is provided and having an energy of greater than the acceleration energy + 1 keV are referred to as fast electrons within the deflector.

[0025] Signal electron beam deflector

[0026] According to one aspect, a signal electron beam deflector for an electron beam device is provided. The signal electron beam deflector includes a first electrode extending in a curved manner and a second electrode extending in a curved manner and having at least one electron-transparent portion configured to allow a portion of the signal electron beam to pass through the at least one electron-transparent portion. The first electrode and the second electrode are arranged adjacent to each other to form a space between the first electrode and the second electrode such that: the space has an inlet opening and an outlet opening, a first optical path is provided between the inlet opening and the outlet opening, and a second optical path is provided between the inlet opening and the at least one electron-transparent portion of the second electrode. The at least one electron-transparent portion may be configured to allow electrons to pass through the at least one electron-transparent portion.

[0027] Figure 1 is a schematic view of a signal electron beam deflector 100 according to an embodiment disclosed herein. The signal electron beam deflector 100 includes a first electrode 110 extending in a curved manner and a second electrode 120 extending in a curved manner. The second electrode 120 has at least one electron-transparent portion 130. The at least one electron-transparent portion may be configured to allow a portion of the signal electron beam to pass through the at least one electron-transparent portion. The at least one electron-transparent portion 130 is provided in the second electrode 120. In Figure 1 the embodiment of, the at least one electron-transparent portion includes a beam opening provided in the second electrode 120. The first electrode 110 and the second electrode 120 are arranged adjacent to each other to form a space 140 between the first electrode and the second electrode. The space 140 has an inlet opening 150 and an outlet opening 160. A first optical path 170 is provided between the inlet opening 150 and the outlet opening 160. A second optical path 180 is provided between the inlet opening 150 and the at least one electron-transparent portion 130.

[0028] The first electrode 110 extends in a curved manner. The first electrode 110 may extend in an elliptical manner, particularly in a circular manner. The first electrode 110 may extend in an exponential manner. In particular, the first electrode may extend along a first path defined by an elliptical arc, particularly a circular arc, or along a first path defined by an exponential function or a polynomial function. The first electrode 110 may extend in a direction perpendicular to the first path, i.e., having a cross-section such as Figures 3A to 3C shown. The first path may be in the same plane as the first optical path 170. The first path and the first optical path 170 may be parallel curves.

[0029] The second electrode 120 extends in a curved manner. The second electrode 120 may extend in an elliptical manner, particularly a circular manner. The second electrode 120 may extend in an exponential manner. In particular, the second electrode 120 may extend along a second path defined by an elliptical arc, particularly a circular arc, or along a second path defined by an exponential function or a polynomial function. The second electrode 120 may extend in a direction perpendicular to the second path, i.e., having a cross-section as shown, for example, in Figures 3A to 3C The second path may be in the same plane as the first optical path 170. In particular, the first path, the second path, and the first optical path 170 may be in the same plane. The second path and the first optical path 170 may be parallel curves. In particular, the first path, the second path, and the first optical path 170 may be parallel curves. The first electrode 110 and the second electrode 120 may be arranged parallel to each other.

[0030] The second electrode may be provided as an electron-transparent grid. Figure 2A An embodiment is illustrated in which the second electrode is provided as an electron-transparent grid. At least one electron-transparent portion 130 may extend substantially over the entire surface of the second electrode 120 provided as an electron-transparent grid. The second electrode may be provided as an electron-transparent foil. Figure 2B An embodiment is illustrated in which the second electrode is provided as an electron-transparent grid. At least one electron-transparent portion 130 may extend substantially over the entire surface of the second electrode 120 provided as an electron-transparent grid. Advantageously, providing the second electrode as an electron-transparent grid or an electron-transparent foil allows electrons to be guided from the entrance opening 150 through substantially any position on the surface of the second electrode provided as an electron-transparent grid or electron-transparent film. The throughput of fast electrons along the second optical path is increased and the loss of fast electrons in the signal electron beam deflector can be reduced. In one embodiment, which may be combined with other embodiments described herein, the second electrode is provided as an electron-transparent grid or an electron-transparent foil such that at least one electron-transparent portion extends substantially over the entire surface of the second electrode provided as an electron-transparent grid or electron-transparent foil.

[0031] In some embodiments, the first electrode extends in an elliptical manner and the second electrode extends in an elliptical manner. In particular, the first electrode extends in a circular manner and the second electrode extends in a circular manner. The first electrode extending in a circular manner and the second electrode extending in a circular manner may be arranged concentrically.

[0032] The space 140 is at least partially formed between the first electrode 110 and the second electrode 120. The first electrode 110 and the second electrode 120 may be arranged to define the space 140 therebetween. The first electrode 110 and the second electrode 120 may define the space 140 without direct contact. The first electrode 110 and the second electrode 120 may form the space 140 as a dotted line (see Figure 3A the dotted line in) between the electrodes and the edges of the first electrode 110 and the second electrode 120, in particular the volume formed between straight lines between the edges of the first electrode 110 and the second electrode 120.

[0033] The space 140 has an inlet opening 150 and an outlet opening 160. The inlet opening 150 may be configured to allow a signal electron beam to pass through the inlet opening 150. The outlet opening 160 may be configured to allow a part of the signal electron beam to pass through the outlet opening 160. The outlet opening 160 may be configured to allow the signal electron beam to pass through the outlet opening 160. The signal electron beam may enter the space 140 through the inlet opening 150. The signal electron beam may leave the space 140 through the outlet opening 160. The signal electron beam may propagate inside the space 140. The signal electrons may propagate along a first optical path 170. The signal electron beam may propagate along a second optical path 180.

[0034] The first optical path 170 is provided between the inlet opening 150 and the outlet opening 160. The first optical path may extend from the inlet opening 150 to the outlet opening 160. The first optical path may be provided within the space 140. The first optical path 170 may be provided between the first electrode 110 and the second electrode 120. The signal electron beam may be guided along the first optical path. The signal electron beam may enter the space 140 through the inlet opening 150. The signal electron beam may leave the space through the outlet opening 160.

[0035] The second optical path 180 is provided between the inlet opening 150 and at least one electron-transparent portion 130. The second optical path 180 may extend from the inlet opening to at least one electron-transparent portion 130. The signal electron beam propagating in the space 140 between the first electrode 110 and the second electrode 120 may pass through at least one electron-transparent portion 130 and through the second electrode. The signal electron beam may be guided along the second optical path. The signal electron beam may enter the space 140 through the inlet opening 150 and leave the space 140 through at least one electron-transparent portion 130.

[0036] At least one electron-transparent portion 130 may include a beam opening provided in the second electrode 120. The beam opening may be configured to allow a portion of the signal electron beam to pass through the beam opening. The beam opening may be configured to allow the signal electron beam to pass through the beam opening. The beam opening may include one or more openings provided in the second electrode 120. In particular, the one or more openings provided in the second electrode 120 may be through-holes. One or more openings may be provided in the electrode. The one or more openings provided as through-holes in the second electrode 120 may extend through the second electrode 120. One or more openings may be configured to allow a portion of the signal electron beam to pass through the one or more openings. The second optical path 180 may be provided between the entrance opening 150 and at least one of the one or more openings included in the beam opening. The second optical path 180 may extend from the entrance opening 150 to at least one of the one or more openings included in the beam opening. The signal electron beam may leave the space 140 through the beam opening. In particular, the signal electron beam may leave the space 140 through at least one of the one or more openings of the beam opening.

[0037] The beam opening may be a slit in the second electrode 120. The slit may extend partially or completely between the first end of the second electrode and the second end of the first electrode. The first end of the second electrode may be adjacent to the entrance opening. The second end of the second electrode may be adjacent to the exit opening. The slit may be arranged at any position between the first end and the second end of the second electrode. The second optical path 180 may extend from the entrance opening 150 to the slit in the second electrode 120 provided as the beam opening. The signal electron beam may leave the space 140 through the slit in the second electrode 120 provided as the beam opening. In one embodiment, at least one electron-transparent portion 130 includes the beam opening in the second electrode. In particular, the beam opening is a slit in the second electrode that extends between the first end of the second electrode at the entrance opening and the second end of the second electrode at the exit opening.

[0038] An electron-transparent grid or an electron-transparent foil may be provided to overlap the beam opening partially or completely.

[0039] In one embodiment, a signal electron beam deflector for an electron beam device is provided. The signal electron beam deflector includes: a first electrode 110 extending in a curved manner; a second electrode 120 extending in a curved manner and having at least one electron-transparent portion; and a beam opening provided in the second electrode 120. The first electrode 110 and the second electrode 120 are arranged adjacent to each other to form a space 140 between the first electrode and the second electrode, such that: the space 140 has an inlet opening 150 and an outlet opening 160; a first optical path 170 is provided between the inlet opening 150 and the outlet opening 160; and a second optical path 180 is provided between the inlet opening 150 and the beam opening provided in the second electrode.

[0040] The first optical path 170 may be bent at a first angle α, as Figure 1 shown. The first electrode extending in a curved manner may be bent at the first angle α. The second electrode extending in a curved manner may be bent at the first angle α. The first angle α is defined between the direction of the first optical path 170 at the position of the inlet opening 150 and the direction of the first optical path 170 at the position of the outlet opening 160. The first angle α may be between 30° and 90°.

[0041] The signal electron beam propagating along the first optical path 170 through the signal electron beam deflector 100 may enter the signal electron beam deflector through the inlet opening 150 having a first propagation direction. The signal electron beam may leave the signal electron beam deflector through the outlet opening 160 having a second propagation direction. The second propagation direction may have a first angle α relative to the first propagation direction. In particular, the signal electron beam may enter the signal electron beam deflector 100 through the inlet opening 150 having a first propagation direction. The slow signal electron beam may leave the signal electron beam deflector 100 through the outlet opening having a second propagation direction. The second propagation direction of the slow signal electron beam may have a first angle α relative to the first propagation direction of the signal electron beam. The signal electron beam deflector 100 may deflect the electrons guided along the first optical path by the first angle α. The signal electron beam deflector 100 may deflect the slow electrons by the first angle α.

[0042] The second optical path 180 may be bent at a second angle β, as Figure 1 shown. At least one electron-transparent portion may be provided in the second electrode such that the second optical path may be bent at the second angle β. The second angle β is measured between the direction of the second optical path 180 at the position of the inlet opening 150 and the direction of the second optical path at the position of at least one electron-transparent portion 130. The second angle β may be between substantially 10° and 80°. The second angle β may be less than the first angle α. In one embodiment, the first angle α is between 80° and 90° and the second angle β is between 30° and 80°.

[0043] The signal electron beam propagating along the second optical path 180 through the signal electron beam deflector 100 can enter the signal electron beam deflector through the entrance opening 150 having a first propagation direction. The signal electron beam can leave the signal electron beam deflector through at least one electron-transparent portion 130 having a second propagation direction. The second propagation direction can have a second angle β with respect to the first propagation direction. In particular, the signal electron beam can enter the signal electron beam deflector 100 through the entrance opening 150 having a first propagation direction. The fast signal electron beam can leave the signal electron beam deflector 100 through at least one electron-transparent portion 130 having a second propagation direction. The second propagation direction of the fast signal electron beam can have a second angle β with respect to the first propagation direction of the signal electron beam. The signal electron beam deflector 100 can deflect the electrons guided along the second optical path by the second angle β. The signal electron beam deflector can deflect the fast electrons by the second angle β.

[0044] The first electrode 110 can be made of a conductive material. The first electrode can be configured to apply a first voltage to the first electrode. The first electrode 110 can be configured to provide a first electric field. A first voltage can be applied to the first electrode 110 to provide a first electric field through the first electrode.

[0045] The second electrode 120 can be made of a conductive material. The second electrode can be configured to apply a second voltage to the second electrode. The second electrode 120 can be configured to provide a second electric field. A second voltage can be applied to the second electrode 120 to provide a second electric field through the second electrode.

[0046] The first electric field and / or the second electric field can be used to deflect the signal electron beam propagating through the signal electron beam deflector. The first electric field and / or the second electric field can deflect the slow electrons of the signal electron beam along the first optical path. The first electric field and / or the second electric field can deflect the fast electrons of the signal electron beam along the second optical path. Interference within the first electric field and / or the second electric field may interfere with the deflection of the slow electrons and / or the fast electrons.

[0047] At least one electron-transparent portion can include an electron-transparent grid. The electron-transparent grid can be integrally formed with the second electrode. The electron-transparent grid can be configured to allow a portion of the signal electron beam to pass through the electron-transparent grid.

[0048] The electron-transparent grid can include a plurality of overlapping wiring or nanostructures forming a grid. The plurality of overlapping wiring or nanostructures can form a plurality of openings between the plurality of overlapping wiring or nanostructures. The electron beam can pass through the plurality of openings between the plurality of overlapping wiring or nanostructures. The electron-transparent grid can be highly transparent to electrons. The grid can have an electron transparency greater than 50%, particularly greater than 70%. The grid can be implemented in a microelectromechanical system (MEMS).

[0049] The electron transparent grid can be configured to apply a voltage to the electron transparent grid. The electron transparent grid can be electrically connected to the second electrode 120. The electron transparent grid can be configured to apply the same voltage to the electron transparent grid as that applied to the second electrode 120. In particular, the electron transparent grid can be configured to apply a second voltage to the electron transparent grid. The electron transparent grid can compensate for or eliminate interference in the second electric field provided by the second electrode 120. For example, the electron transparent grid can compensate for or eliminate interference in the second electric field, which may be caused by irregularities in the second electrode (e.g., openings in the second electrode). According to one embodiment, at least one electron transparent part includes the electron transparent grid.

[0050] At least one electron transparent part can include an electron transparent foil. The electron transparent foil can be configured to allow electrons to pass through the electron transparent foil. The electron transparent foil can be integrally formed with the second electrode 120 of the second electrode. The electron transparent foil can be highly transparent to electrons. The electron transparent foil can have an electron transparency greater than 50%, particularly greater than 70%.

[0051] The electron transparent foil can be configured to apply a voltage to the electron transparent foil. The electron transparent foil can be electrically connected to the second electrode. The electron transparent foil can be configured to apply the same voltage to the electron transparent foil as that applied to the second electrode. In particular, the electron transparent foil can be configured to apply a second voltage to the electron transparent foil. The electron transparent foil can compensate for or eliminate interference in the second electric field provided by the second electrode 120. For example, the electron transparent grid can compensate for or eliminate interference in the second electric field, which may be caused by irregularities in the second electrode (e.g., openings in the second electrode). According to one embodiment, at least one electron transparent part includes the electron transparent foil.

[0052] According to one aspect, a signal electron beam deflector for an electron beam device is provided. The signal electron beam deflector includes a first electrode and a second electrode that provides a first optical path therebetween, and at least one electron transparent part provided in the second electrode. A second optical path is provided, and the second optical path passes through at least one electron transparent part, and the signal electron beam deflector is configured to guide electrons of the signal electron beam along the first optical path and along the second optical path according to the energy of the electrons of the signal electron beam. At least one electron transparent part can be configured to allow signal electrons to pass through at least one electron transparent part

[0053] In some embodiments, at least one electron-transparent portion includes an electron-transparent grid or an electron-transparent foil. In some embodiments, the signal electron beam deflector is configured to direct slow electrons of a signal electron beam having an energy of less than 500 eV after emission or release from the sample along a first optical path, and to direct fast electrons of a signal electron beam having an energy of greater than 1 keV after emission or release from the sample along a second optical path. In some embodiments, at least one electron-transparent portion 130 includes a beam opening in the second electrode. The beam opening may be a slit in the second electrode that extends between a first end of the second electrode at an inlet opening and a second end of the second electrode at an outlet opening.

[0054] The signal electron beam deflector 100 according to the embodiments described herein allows the signal electron beam to be deflected such that slow signal electrons are directed along a first optical path and fast signal electrons are directed along a second optical path. At least one electron-transparent portion 130 provides an exit for the fast signal electrons. Advantageously, fast signal electrons having an energy of up to 20 keV, and even up to 100 keV, after emission or release from the sample can be directed along the second optical path. At the same time, slow signal electrons having an energy of less than 1 keV, in particular less than 100 eV, after release or emission from the sample can be directed along the first optical path.

[0055] Cross-sectional shape

[0056] Now referring to Figures 3A to 3C , cross-sectional views of the first electrode 110 and the second electrode 120 are illustrated for different embodiments. The first electric field provided by the first electrode may depend on the cross-sectional shape of the first electrode. In particular, the first electric field within the space 140 may depend on the first cross-sectional shape of the first electrode. The second electric field provided by the second electrode may depend on the second cross-sectional shape of the second electrode. In particular, the second electric field within the space 140 may depend on the cross-sectional shape of the second electrode.

[0057] As Figures 3A to 3C shown, the first electrode 110 and / or the second electrode having the first / second cross-sectional shape may extend in a direction into and / or out of the plane of the paper. As described herein, the first electrode 110 and / or the second electrode may be curved in a direction into and / or out of the plane of the paper.

[0058] Figure 3A Cross-sectional views of the first electrode and the second electrode according to the embodiments described herein are illustrated. A first portion of the first electrode is bounded by a straight line. A second portion of the second electrode is bounded by a straight line. The first optical path 170 may be provided between the first portion and the second portion. The first electrode and the second electrode are arranged parallel to each other. Figure 3AIllustrated is at least one electron-transparent portion 130 of a beam opening provided in a second electrode. The beam opening may be provided as a slit in the second electrode that extends between a first end of the second electrode at an inlet opening and a second end of the second electrode at an outlet opening.

[0059] In some embodiments that may be combined with other embodiments described herein, the first electrode may have a first cross-section in a plane perpendicular to the first optical path, and the second electrode may have a second cross-section in a plane perpendicular to the first optical path; and a first portion of the first cross-section may be bounded by a straight line, and a second portion of the second cross-section may be bounded by a straight line.

[0060] Figure 3B Illustrated is a cross-sectional view of a first electrode 110 and a second electrode 120 according to an embodiment described herein. A first portion of the first electrode is bounded by an arc. A second portion of the second electrode is bounded by an arc. A first optical path 170 may be provided between the first portion and the second portion. The arcs bounding the first portion and / or the second portion may have any suitable shape. The arcs may have any suitable opening angle and / or any suitable radius. In one embodiment, the first portion bounded by an arc and the second portion bounded by an arc are concentric. The first portion bounded by an arc and the second portion bounded by an arc may be curved in the same direction. Figure 3B Illustrated is a second electrode 120 provided as an electron-transparent grid. At least one electron-transparent portion 130 extends substantially over the entire surface of the second electrode provided as an electron-transparent grid.

[0061] In some embodiments that may be combined with other embodiments described herein, the first electrode may have a first cross-section in a plane perpendicular to the first optical path, and the second electrode may have a second cross-section in a plane perpendicular to the first optical path; and a first portion of the first cross-section may be bounded by an elliptical arc, and a second portion of the second cross-section may be bounded by an elliptical arc. The elliptical arcs bounding the first electrode and / or the second electrode may have any suitable shape. The elliptical arcs may have any suitable opening angle and any suitable lengths of major and minor axes, particularly any suitable ratio of the major and minor axes. In one embodiment, the major and minor axes may have the same length, thereby forming an arc.

[0062] Figure 3CA cross-sectional view of a first electrode 110 and a second electrode according to an embodiment described herein is illustrated. A first portion of the first electrode may be defined by a polynomial. A second portion of the second electrode may be defined by an exponential function. A first optical path 170 may be provided between the first portion and the second portion. The first portion of the first electrode may be different from the second portion of the second electrode. Advantageously, the hexapole component of the electric field may thereby be reduced or compensated. The first optical path may be provided between the first portion and the second portion. Figure 3C The second electrode 120 provided as an electron-transparent foil is illustrated. At least one electron-transparent portion 130 extends substantially over the entire surface of the second electrode provided as an electron-transparent foil.

[0063] Although Figures 3A to 3C A second cross-sectional shape in combination with certain ones of the at least one electron-transparent portion is illustrated, but it will be understood that any suitable cross-sectional shape of the second electrode may have any suitable at least one electron-transparent portion. For example, Figure 3B the second electrode 120 shown may have at least one electron-transparent portion including a beam aperture, or Figure 3B the second electrode 120 shown may be provided as an electron-transparent foil and at least one electron-transparent portion 130 may extend substantially over the entire surface of the second electrode 120 provided as an electron-transparent foil.

[0064] According to one embodiment that may be combined with other embodiments described herein, the first electrode may have a first cross-section in a plane perpendicular to the first optical path, and the second electrode may have a second cross-section in a plane perpendicular to the first optical path; and a first portion of the first cross-section and a second portion of the second cross-section may have the first optical path therebetween, and wherein the first portion of the first cross-section may be defined by a polynomial, and the second portion of the second cross-section may be defined by an exponential function. At least a portion of the first electrode may be defined by rotation of a polynomial about a first axis, and / or at least a portion of the second electrode may be defined by rotation of an exponential about a second axis.

[0065] In some embodiments, the first electrode may have a first cross-section in a plane perpendicular to the first optical path, and the second electrode may have a second cross-section in a plane perpendicular to the first optical path; and a first portion of the first cross-section and a second portion of the second cross-section may have the first optical path therebetween, and wherein the first portion of the first cross-section may be defined by an analytical function or coordinate data points and / or the second portion of the second cross-section may be defined by an analytical function or coordinate data points.

[0066] Electron beam device

[0067] Figure 4FIG. shows a schematic diagram of an electron beam apparatus 200 according to the present disclosure. The electron beam apparatus has a signal electron beam deflector 100 according to the present disclosure. The electron beam apparatus includes an electron source 205 configured to generate a primary electron beam 201, a beam splitter 220, and an objective lens 230.

[0068] As Figure 4 shown, the electron source 205 is configured to generate a primary electron beam 201. The primary electron beam 201 can be directed towards the sample 210. The primary electron beam 201 can be guided through the beam splitter 220 in a first propagation direction. The primary electron beam 201 can pass through the beam splitter and can be directed towards the sample 210 placed on the sample stage.

[0069] The primary electron beam 201 can pass through the objective lens 230. The objective lens 230 can focus the primary electron beam 201 on the surface of the sample 210. The primary electron beam 201 can impinge on the sample 210. The primary electron beam 201 can be accelerated between the electron source 205 and the sample 210. In particular, the primary electron beam 201 can be accelerated between the objective lens 230 and the sample 210. The primary electron beam 201 can be accelerated such that the primary electron beam 201 has an energy of up to 20 keV, in particular up to 100 keV, when it impinges on the sample.

[0070] After the primary electron beam 201 impinges on the sample 210, a signal electron beam is emitted from the sample. The signal electron beam can include backscattered electrons (BSE) and / or secondary electrons (SE). After being emitted from the sample surface, the signal electron beam can have an energy of up to 20 keV, in particular up to 100 keV. After being emitted from the sample surface, the BSE can have an energy between 1 keV and 100 keV. After being emitted from the sample surface, the SE can have an energy of up to 50 eV. The signal electron beam can be guided through the objective lens 230. The signal electron beam can be guided through the beam splitter 220.

[0071] The beam splitter 220 can be configured to separate the primary electron beam 201 and the signal electron beam 202. In the space between the beam splitter 220 and the sample 210, the primary electron beam and the signal electron beam can propagate along the same path. The primary electron beam 201 can propagate from the electron source 205 to the beam splitter 220 along a first path. The signal electron beam 202 can propagate from the beam splitter towards the signal electron beam deflector 100 along a second path. The beam splitter can deflect the primary electron beam 201 and the signal electron beam 202 such that the first path and the second path do not overlap.

[0072] For example, the beam splitter 220 can be a magnetic beam splitter, and the deflection of the electron beam propagating through the beam splitter 220 can depend on the propagation direction of the electron beam. The primary electron beam 201 can propagate through the beam splitter 220 along a first propagation direction. The beam splitter can deflect the primary electron beam 201 such that the primary electron beam propagates along a deflected first propagation direction. The primary electron beam 201 can propagate between the beam splitter and the sample along the deflected first propagation direction. The signal electron beam can propagate between the sample and the beam splitter along a second propagation direction. The second propagation direction can be substantially anti-parallel to the deflected first propagation direction. The beam splitter 220 can deflect the signal electron beam 202 such that the signal electron beam 202 propagates along the deflected second propagation direction. The signal electron beam 202 can propagate along the deflected second propagation direction. The first propagation direction and the deflected second propagation direction may not be parallel and not anti-parallel. The signal electron beam 202 can leave the beam splitter 220 at a position different from the position where the primary electron beam 201 enters the beam splitter 220.

[0073] As Figure 4 shown, the signal electron beam 202 can propagate from the beam splitter 220 towards the signal electron beam deflector 100. Accelerating energy can be provided to the signal electron beam 202. The accelerating energy can be provided during the propagation of the signal electron beam from the sample or the beam splitter 220 towards the signal electron beam deflector. The accelerating energy can be provided by an accelerating voltage V a provided. The accelerating voltage can be up to 10 kV, even up to 30 kV. The accelerating voltage can be between 10 kV and 30 kV. The accelerating energy can be up to 10 keV, even up to 30 keV. The accelerating energy can be between 10 keV and 30 keV.

[0074] The signal electron beam deflector 100 can be according to the embodiments described herein. The signal electron beam 202 can enter the signal electron beam deflector through an entrance opening. The slow electrons can be guided along a first optical path provided in the signal electron beam deflector. The slow electrons can leave the signal electron beam deflector 100 through an exit opening. The slow electrons leaving the signal electron beam deflector 100 through the exit opening can form a slow signal electron beam. The fast electrons can be guided along a second optical path provided in the signal electron beam deflector. The fast electrons can leave the signal electron beam deflector 100 through at least one electron transparent portion. The fast electrons leaving the signal electron beam deflector 100 through the at least one electron transparent portion can form a fast signal electron beam.

[0075] The electron beam device may include one or more holes. The entrance hole 240 may be positioned adjacent to the entrance opening of the signal electron beam deflector. The first hole 245a may be positioned adjacent to the exit opening of the signal electron beam deflector. The second hole 245b may be positioned adjacent to at least one electron transparent portion of the signal electron beam deflector. By shaping at least one of the entrance hole 240, the first hole 245a, and / or the second hole 245b in a triangular manner, the hexapole of the electric edge field can be reduced.

[0076] The electron beam device may include a first detector arm 280a for detecting the slow electrons of the signal electron beam. In particular, for detecting the slow signal electron beam. The first detector arm 280a may include a first hole 245a, a first focusing lens 250a for focusing the slow signal electron beam 202a, a first deflector 260a for adjusting the path of the slow signal electron beam 202a, and / or a first detector 270a for detecting the slow signal electron beam. The first detector arm may include a first detector arm optical axis. The first hole 245a, the first focusing lens 250a, the first deflector 260a, and / or the first detector 270a may be aligned with the first detector arm optical axis. The first detector arm may be placed adjacent to the exit opening 160 of the signal electron beam deflector 100. In particular, such that the first hole 245a is positioned adjacent to the exit opening 160 of the signal electron beam deflector 100. The first detector arm may be aligned with the first optical path. In particular, the first detector arm optical axis may be aligned with the first optical path. The first detector arm may be placed such that the first detector arm optical axis is parallel to the direction of the first optical path at the exit opening. In particular, placed such that the first detector arm optical axis and the first optical path merge.

[0077] The slow signal electron beam may leave the signal electron beam deflector 100 through the exit opening 160. The slow signal electron beam may propagate through the first hole 245a. The slow signal electron beam may propagate through the first focusing lens 250a. The first focusing lens 250a may focus the slow signal electron beam to the position of the first detector 270a. The slow signal electron beam may propagate through the first deflector 260a. The first deflector 260a may adjust the position where the slow signal electron beam strikes the first detector 270a. The first detector 270a may detect the slow signal electron beam. The first detector 270 may image the sample 210.

[0078] The electron beam device may include a second detector arm 280b for detecting fast electrons of the signal electron beam. In particular, for detecting the fast signal electron beam. The second detector arm 280b may include a second aperture 245b, a second focusing lens 250b for focusing the fast signal electron beam 202b, a second deflector 260b for adjusting the path of the fast signal electron beam 202b, and / or a second detector 270b for detecting the fast signal electron beam. The second detector arm may include a second detector arm optical axis. The second aperture 245b, the second focusing lens 250b, the second deflector 260b, and / or the second detector 270b may be aligned with the second detector arm optical axis. The second detector arm optical axis may be placed adjacent to at least one electron-transparent portion of the signal electron beam deflector 100. In particular, such that the second aperture 245b is positioned adjacent to at least one electron-transparent portion of the signal electron beam deflector 100. The second detector arm may be aligned with a second optical path. In particular, the second detector arm axis may be aligned with the first optical path. The second detector arm may be placed such that the second detector arm optical axis is parallel to the direction of the second optical path at the exit opening. In particular, placed such that the second detector arm optical axis and the second optical path merge.

[0079] The fast signal electron beam may exit the signal electron beam deflector 100 through at least one electron-transparent portion 130. The fast signal electron beam may propagate through the second aperture 245b. The slow signal electron beam may propagate through the second focusing lens 250b. The second focusing lens 250b may focus the fast signal electron beam to the position of the second detector 270b. The fast signal electron beam may propagate through the second deflector 260b. The second deflector 260b may adjust the position where the fast signal electron beam impinges on the second detector 270b. The second detector 270b may detect the fast signal electron beam. The second detector 270b may image the sample 210.

[0080] According to one aspect, an electron beam device is provided. According to the embodiments described herein, the electron beam device includes a sample stage, a deflector system, an electron source adapted to generate a primary electron beam, and a signal electron beam deflector.

[0081] Method for deflecting a signal electron beam

[0082] Figure 5The figure shows a flowchart of a method for deflecting a signal electron beam according to an embodiment described herein. At operation 510, a signal electron beam can be directed from a sample to a signal electron beam deflector. The signal electron beam deflector has a first electrode and a second electrode. The signal electron beam deflector can be a signal electron beam deflector according to an embodiment described herein. The signal electron beam can be emitted from the sample after the primary electron beam impacts. The primary electron beam can have an energy of up to 20 keV, particularly up to 100 keV. The signal electron beam can include backscattered electrons and / or secondary electrons.

[0083] At operation 520, slow electrons of the signal electron beam having an energy of less than 500 eV after being emitted or released from the sample can be directed along a first optical path. In particular, the slow electrons can include secondary electrons and / or low-energy backscattered electrons. The first optical path is provided between an entrance opening and an exit opening of the signal electron beam deflector. The directing of the slow electrons of the signal electron beam can include deflecting the slow electrons by a first electric field provided by the first electrode and / or a second electric field provided by the second electrode. The slow electrons can be deflected by a first angle α. The first angle α is measured between the propagation direction of the slow electrons when entering the signal electron beam deflector (i.e., the propagation direction of the signal electron beam when entering the signal electron beam deflector) and the propagation direction of the slow electrons when leaving the signal electron beam deflector. The first angle α can be between 30° and 90°.

[0084] At operation 530, fast electrons of the signal electron beam having an energy of greater than 1 keV after being emitted or released from the sample can be directed along a second optical path. In particular, the fast electrons can include backscattered electrons. The second optical path is provided between the entrance opening and at least one electron-transparent portion provided in the second electrode of the signal electron beam deflector. The directing of the fast electrons of the signal electron beam can include deflecting the fast electrons by the first electric field and / or by the second electric field. The fast electrons can be deflected by a second angle β. The second angle β is measured between the propagation direction of the fast electrons when entering the signal electron beam deflector (i.e., the propagation direction of the signal electron beam when entering the signal electron beam deflector) and the propagation direction of the fast electrons when leaving the signal electron beam deflector. The second angle β can be between substantially 10° and 80°. The second angle β can be less than the first angle α. In one embodiment, the first angle α is between 80° and 90° and the second angle β is between 30° and 80°.

[0085] According to one aspect, a method for deflecting a signal electron beam is provided. The method includes: guiding the signal electron beam from a sample to a signal electron beam deflector having a first electrode and a second electrode; guiding slow electrons of the signal electron beam along a first optical path provided between an entrance opening and an exit opening of the signal electron beam deflector; and guiding fast electrons of the signal electron beam along a second optical path provided between the entrance opening and at least one electron-transparent portion provided in the second electrode of the signal electron beam deflector. The signal electron beam deflector can be the signal electron beam deflector according to the embodiments described herein.

[0086] The method can include an additional operation of detecting the slow electrons by a first detector and / or detecting the fast electrons by a second detector. The first detector can detect the slow electrons to image the sample. The second detector can detect the fast electrons to image the sample.

[0087] According to one embodiment, the slow electrons have an energy of less than 1 keV after being emitted or released from the sample, while the fast electrons have an energy of greater than 1 keV and, for example, less than 200 keV or less than 100 keV after being emitted or released from the sample. In particular, the slow electrons can have an energy of less than 100 eV after being emitted or released from the sample.

[0088] According to one embodiment, the first electrode and the second electrode are arranged adjacent to each other to form a space between the first electrode and the second electrode such that the space has an entrance opening and an exit opening.

[0089] According to an embodiment that can be combined with further embodiments described herein, the method can further include providing a first voltage to the first electrode of the signal electron beam deflector to generate a first electric field; providing a second voltage to the second electrode of the signal electron beam deflector to generate a second electric field; deflecting the slow electrons by the first electric field and by the second electric field; and deflecting the fast electrons by the first electric field and by the second electric field. Deflecting the slow electrons by the first electric field and by the second electric field can guide the slow electrons along the first optical path. Deflecting the fast electrons by the first electric field and by the second electric field can guide the fast electrons along the second optical path.

[0090] According to one embodiment, the method further includes applying a second voltage to an electron-transparent grid provided as at least one electron-transparent portion. According to one embodiment, the method further includes applying a second voltage to an electron-transparent foil provided as at least one electron-transparent portion.

[0091] According to an embodiment that can be combined with further embodiments described herein, guiding slow electrons along a first optical path includes deflecting the slow electrons by a first angle α, where the first angle α is between 30° and 90°, and guiding fast electrons along a second optical path includes deflecting the fast electrons by a second angle β, where the second angle β is between 0° and 80°. In particular, the first angle α is between 80° and 90° and the second angle β is between 30° and 80°.

[0092] According to one embodiment, guiding a signal electron beam from a sample to a signal electron beam deflector includes accelerating the signal electron beam using an acceleration voltage V between the sample and the signal electron beam deflector a to accelerate the signal electron beam, where the acceleration voltage V a is between 10 keV and 30 keV.

[0093] Embodiments of the present disclosure may include the following clauses.

[0094] Clause 1. A signal electron beam deflector for an electron beam device, the signal electron beam deflector comprising: a first electrode extending in a curved manner; and a second electrode extending in a curved manner and having at least one electron-transparent portion; the first electrode and the second electrode being arranged adjacent to each other to form a space between the first electrode and the second electrode such that: the space has an inlet opening and an outlet opening; a first optical path is provided between the inlet opening and the outlet opening; and a second optical path is provided between the inlet opening and the at least one electron-transparent portion of the second electrode.

[0095] Clause 2. The signal electron beam deflector according to clause 1, wherein the at least one electron-transparent portion includes an electron-transparent grid.

[0096] Clause 3. The signal electron beam deflector according to clause 1, wherein the at least one electron-transparent portion includes an electron-transparent foil.

[0097] Clause 4. The signal electron beam deflector according to any one of clauses 1 to 3, wherein the at least one electron-transparent portion includes a beam opening in the second electrode, in particular wherein the beam opening is a slit in the second electrode extending between a first end of the second electrode at the inlet opening and a second end of the second electrode at the outlet opening.

[0098] Clause 5. The signal electron beam deflector according to any one of clauses 1 to 4, wherein: the second electrode is provided as an electron-transparent grid or an electron-transparent foil such that the at least one electron-transparent portion extends substantially above the entire surface of the second electrode provided as the electron-transparent grid or the electron-transparent foil.

[0099] Clause 6. A signal electron beam deflector as described in any one of Clauses 1 to 5, wherein: the first electrode has a first cross-section in a plane perpendicular to the first optical path, and the second electrode has a second cross-section in the plane perpendicular to the first optical path; and a first part of the first cross-section is bounded by an elliptical arc, and a second part of the second cross-section is bounded by an elliptical arc.

[0100] Clause 7. A signal electron beam deflector as described in any one of Clauses 1 to 6, wherein the first electrode extends in an elliptical manner and the second electrode extends in an elliptical manner.

[0101] Clause 8. A signal electron beam deflector as described in any one of Clauses 1 to 5 and 7, wherein: the first electrode has a first cross-section in a plane perpendicular to the first optical path, and the second electrode has a second cross-section in the plane perpendicular to the first optical path; and a first part of the first cross-section and a second part of the second cross-section provide the first optical path therebetween, and wherein the first part of the first cross-section is bounded by a polynomial and the second part of the second cross-section is bounded by an exponential function.

[0102] Clause 9. A signal electron beam deflector as described in any one of Clauses 1 to 8, wherein the at least one electron-transparent part is configured to allow signal electrons to pass through the at least one electron-transparent part.

[0103] Clause 10. A signal electron beam deflector as described in any one of Clauses 1 to 8, wherein the at least one electron-transparent part is configured to allow a part of the signal electron beam to pass through the at least one electron-transparent part.

[0104] Clause 11. A signal electron beam deflector for an electron beam device, the signal electron beam deflector comprising: a first electrode and a second electrode, with a first optical path provided therebetween; and at least one electron-transparent part provided in the second electrode; wherein: a second optical path is provided, the second optical path passing through the at least one electron-transparent part; and the signal electron beam deflector is configured to direct electrons of the signal electron beam along the first optical path and along the second optical path depending on the energy of the electrons of the signal electron beam.

[0105] Clause 12. A signal electron beam deflector as described in Clause 11, wherein the at least one electron-transparent part comprises an electron-transparent grid or an electron-transparent foil.

[0106] Clause 13. A signal electron beam deflector as described in any one of Clauses 11 and 12, wherein the signal electron beam deflector is configured to direct slow electrons of the signal electron beam having an energy less than 500 eV after being emitted or released from the sample along the first optical path, and to direct fast electrons of the signal electron beam having an energy greater than 1 keV after being emitted or released from the sample along the second optical path.

[0107] Clause 14. A signal electron beam deflector as described in any one of Clauses 11 to 13, wherein the at least one electron transparent portion is configured to allow signal electrons to pass through the at least one electron transparent portion.

[0108] Clause 15. A signal electron beam deflector as described in any one of Clauses 11 to 13, wherein the at least one electron transparent portion is configured to allow a portion of the signal electron beam to pass through the at least one electron transparent portion.

[0109] Clause 16. An electron beam device, comprising: a sample stage; a deflector system; an electron source adapted to generate a primary electron beam; and a signal electron beam deflector as described in Clauses 1 to 15.

[0110] Clause 17. A method of deflecting a signal electron beam, the method comprising: directing the signal electron beam from a sample to a signal electron beam deflector having a first electrode and a second electrode; directing slow electrons of the signal electron beam along a first optical path provided between an entrance opening and an exit opening of the signal electron beam deflector; and directing fast electrons of the signal electron beam along a second optical path provided between the entrance opening and at least one electron transparent portion provided in the second electrode of the signal electron beam deflector.

[0111] Clause 18. The method as described in Clause 17, wherein the slow electrons have an energy less than 1 keV or less than 100 eV after being emitted or released from the sample, and the fast electrons have an energy greater than 1 keV after being emitted or released from the sample.

[0112] Clause 19. The method as described in any one of Clauses 17 to 18, wherein directing the signal electron beam from the sample to the signal electron beam deflector includes accelerating the signal electron beam using an acceleration voltage V a between the sample and the signal electron beam deflector, the acceleration voltage V a being between 10 kV and 30 kV.

[0113] Clause 20. A method as described in any one of Clauses 17 to 19, wherein the first electrode and the second electrode are arranged adjacent to each other to form a space between the first electrode and the second electrode, such that the space has the inlet opening and the outlet opening.

[0114] Clause 21. A method as described in any one of Clauses 17 to 20, further comprising: providing a first voltage to the first electrode of the signal electron beam deflector to generate a first electric field; providing a second voltage to the second electrode of the signal electron beam deflector to generate a second electric field; deflecting the slow electrons through the first electric field and through the second electric field; and deflecting the fast electrons through the first electric field and through the second electric field.

[0115] Clause 22. A method as described in Clause 21, further comprising: applying the second voltage to an electron transparent grid provided as the at least one electron transparent portion, the electron transparent grid.

[0116] Clause 23. A method as described in Clause 21, further comprising: applying the second voltage to an electron transparent foil provided as the at least one electron transparent portion.

[0117] Clause 24. A method as described in any one of Clauses 17 to 23, wherein guiding the slow electrons along the first optical path includes deflecting the slow electrons by a first angle α, the first angle α being between 30° and 90°, and guiding the fast electrons along the second optical path includes deflecting the fast electrons by a second angle β, the second angle β being between substantially 10° and 80°, particularly the first angle α being between 80° and 90° and the second angle β being between 30° and 80°.

[0118] Clause 25. A method as described in any one of Clauses 17 to 24, wherein the signal electron beam deflector is a signal electron beam deflector as described in any one of Clauses 1 to 15.

[0119] While the foregoing is directed to embodiments of the present disclosure, other and additional embodiments of the present disclosure may be devised without departing from the basic scope thereof, and the scope of the present disclosure is determined by the appended claims.

Claims

1. A signal electron beam deflector (100) for an electron beam device, the signal electron beam deflector (100) comprising: A first electrode (110) extending in a curved manner; as well as a second electrode (120) extending in a curved manner and having at least one electron transparent portion; The first electrode (110) and the second electrode (120) are arranged adjacent to each other to form a space (140) between the first electrode and the second electrode, such that: The space (140) has an inlet opening (150) and an outlet opening (160); providing a first optical path (170) between the entrance opening (150) and the exit opening (160); and A second optical path (180) is provided between the entrance opening (150) and the at least one electron transparent portion (130) of the second electrode.

2. The signal electron beam deflector of claim 1, wherein the at least one electron transparent portion comprises an electron transparent grid.

3. The signal electron beam deflector according to claim 1, wherein the at least one electron transparent portion comprises an electron transparent foil.

4. A signal electron beam deflector according to claim 1, wherein the at least one electron transparent portion (130) includes a beam opening in the second electrode, and wherein the beam opening is a slit in the second electrode extending between a first end of the second electrode at the entrance opening and a second end of the second electrode at the exit opening.

5. The signal electron beam deflector according to claim 1, wherein: The second electrode is provided as an electron transparent grid or an electron transparent foil such that the at least one electron transparent portion extends substantially over the entire surface of the second electrode provided as an electron transparent grid or an electron transparent foil.

6. The signal electron beam deflector according to any one of claims 1 to 5, wherein: The first electrode (110) has a first cross section in a plane perpendicular to the first optical path (170), and the second electrode (120) has a second cross section in the plane perpendicular to the first optical path (170); and A first portion of the first cross-section is bounded by an elliptical arc, and a second portion of the second cross-section is bounded by an elliptical arc.

7. The signal electron beam deflector according to any one of claims 1 to 5, wherein the first electrode (110) extends in an elliptical manner and the second electrode (120) extends in an elliptical manner.

8. The signal electron beam deflector according to any one of claims 1 to 5, wherein: The first electrode (110) has a first cross section in a plane perpendicular to the first optical path (170), and the second electrode (120) has a second cross section in the plane perpendicular to the first optical path (170); and A first portion of the first cross-section and a second portion of the second cross-section provide the first optical path therebetween, and wherein the first portion of the first cross-section is defined by a polynomial and the second portion of the second cross-section is defined by an exponential function.

9. A signal electron beam deflector (100) for an electron beam device, the signal electron beam deflector comprising: A first electrode (110) and a second electrode (120), providing a first light path therebetween; as well as at least one electron transparent portion (130) provided in the second electrode (120); in: A second optical path (180) is provided, the second optical path passing through the at least one electron transparent portion (130); and The signal electron beam deflector is configured to direct the electrons of the signal electron beam along the first optical path (170) and along the second optical path (180) depending on the energy of the electrons of the signal electron beam.

10. The signal electron beam deflector according to claim 9, wherein the at least one electron transparent portion comprises an electron transparent grid or an electron transparent foil.

11. A signal electron beam deflector according to any one of claims 9 to 10, wherein the signal electron beam deflector is configured to guide slow electrons of the signal electron beam having an energy less than 500 eV after being emitted or released from the sample along the first optical path, and to guide fast electrons of the signal electron beam having an energy greater than 1 keV after being emitted or released from the sample along the second optical path.

12. An electron beam device comprising: Sample stage (211); Deflector system; An electron source (205) adapted to generate a primary electron beam (201); as well as The signal electron beam deflector (100) according to any one of claims 1 to 5.

13. A method for deflecting a signal electron beam, the method comprising: directing a signal electron beam from the sample to a signal electron beam deflector (100), the signal electron beam deflector having a first electrode and a second electrode; directing the slow electrons of the signal electron beam along a first optical path (170), the first optical path being provided between an entrance opening and an exit opening of the signal electron beam deflector; as well as The fast electrons of the signal electron beam are guided along a second optical path (180) provided between the entrance opening and at least one electron transparent portion provided in the second electrode of the signal electron beam deflector.

14. The method of claim 13, wherein the slow electrons have an energy less than 1 keV or less than 100 eV after being emitted or released from the sample, and the fast electrons have an energy greater than 1 keV after being emitted or released from the sample.

15. The method of claim 14, wherein directing the signal electron beam from the sample to the signal electron beam deflector comprises utilizing an accelerating voltage V between the sample and the signal electron beam deflector. a To accelerate the signal electron beam, the acceleration voltage V a Between 10kV and 30kV. 16 . The method according to claim 13 , wherein the first electrode and the second electrode are arranged adjacent to each other to form a space between the first electrode and the second electrode, such that the space has the inlet opening and the outlet opening.

17. The method according to claim 16, further comprising: providing a first voltage to the first electrode (110) of the signal electron beam deflector to generate a first electric field; providing a second voltage to the second electrode (120) of the signal electron beam deflector to generate a second electric field; deflecting the slow electrons by the first electric field and by the second electric field; as well as The fast electrons are deflected by the first electric field and by the second electric field.

18. The method according to claim 17, further comprising: The second voltage is applied to an electron transparent grid or an electron transparent foil provided as the at least one electron transparent portion.

19. The method of claim 17, wherein directing the slow electrons along the first optical path comprises deflecting the slow electrons by a first angle α, the first angle α being between 30° and 90°, and directing the fast electrons along the second optical path comprises deflecting the fast electrons by a second angle β, the second angle β being substantially between 10° and 80°.

20. The method according to claim 13, wherein the signal electron beam deflector is the signal electron beam deflector according to claim 1.

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