JP5324270B2 - Electron beam equipment - Google Patents

Description

  The present invention relates to an electron beam apparatus such as a scanning electron microscope.

  In a scanning electron microscope, a primary electron beam accelerated and emitted from an electron beam source such as an electron gun is focused so that the probe diameter is reduced on the sample surface by the lens action of the objective lens. In this state, the electron beam is scanned two-dimensionally on the sample surface, whereby detected electrons such as secondary electrons and reflected electrons generated from the sample are detected as signals.

  An electron detector for detecting such detected electrons is installed below the objective lens or above the objective lens.

  A detection signal based on the detected electrons detected by the electron detector is amplified as an image signal and sent to the image processing means. The image processing means creates image data based on this detection signal.

  The image data is sent to display means having a display. The display means displays an image (scanned image) based on the image data.

  Here, in an apparatus in which the electron detector is installed above the objective lens, there are few examples in which the electron detector is arranged on the axis of the primary electron beam. In a normal case, the electron detector is often installed at a position off the axis of the primary electron beam (see, for example, Patent Document 1).

  In this case, the detected electrons generated from the sample and raised are deflected toward the electron detector and detected by the electron detector.

  In addition, the detected electrons generated from the sample and rising are made incident on the reflecting plate, whereby secondary electrons generated from the reflecting plate are detected by an electron detector (see, for example, Patent Document 2). .

  On the other hand, when the electron detector is arranged on the axis of the primary electron beam, an electron detector made of a semiconductor element or an electron detector equipped with a scintillator is arranged.

  In each of the scanning electron microscopes as described above, it has been studied to extract and detect detected electrons separately for each energy band.

  However, when an electron detector is installed above the objective lens and the detected electrons are detected separately for each energy band, the energy to be detected is limited due to the spatial restriction above the objective lens inside the electron beam column. It is difficult to arrange two or more types of electron detectors with different bands.

Japanese Patent Laid-Open No. 7-240168 JP-A-9-171791

  In the conventional scanning electron microscope, it is difficult to install two or more types of electron detectors above the objective lens in order to detect the detected electrons separately for each energy band.

  Therefore, it is impossible to simultaneously detect electrons to be detected in different energy bands and acquire a plurality of types of images.

  The present invention has been made in view of the above points, and in an electron beam apparatus having a configuration in which an electron detector is disposed above an objective lens, electrons to be detected are detected separately for each energy band. It is an object of the present invention to provide an electron beam apparatus that can handle the above.

An electron beam apparatus according to the present invention includes an electron beam source that emits an electron beam accelerated by a predetermined acceleration voltage, an objective lens that focuses the electron beam emitted from the electron beam source and irradiates the sample, An electron comprising a scanning coil for scanning the focused electron beam on the sample, and an electron detecting means for detecting the detected electron generated from the sample in response to the scanning of the electron beam and passing through the objective lens An electron detection means is an electron detection means arranged along a trajectory of an electron beam, and detects detected electrons extracted from each gap between a plurality of mesh electrodes to which different voltages are applied and mesh electrodes facing each other. An electron detector that detects each gap, and a ground electrode that surrounds each mesh electrode and has a plurality of holes formed in a portion located between each mesh electrode and the electron detector. And

  In the present invention, the electron detecting means for detecting the detected electrons that have passed through the objective lens are arranged along the trajectory of the electron beam and applied with different voltages, and the plurality of meshes. And an electron detector that detects the detected electrons extracted from the gaps of the mesh electrodes facing each other in the electrode arrangement.

  Here, since different voltages are applied to the mesh electrodes, the detected electrons extracted from the gaps between the mesh electrodes facing each other correspond to energy bands corresponding to the applied voltages, respectively.

  Therefore, by detecting the detected electrons for each gap by the electron detector, the detected electrons can be detected separately for each energy band.

  Thereby, it becomes possible to simultaneously detect electrons to be detected having different energy bands and simultaneously acquire a plurality of types of images (scanned images) based on the detected electrons.

It is a schematic block diagram which shows the electron beam apparatus in this invention.

  Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a schematic configuration diagram showing an electron beam apparatus according to the present invention. This electron beam apparatus has a configuration of a scanning electron microscope.

  In the figure, an electron beam 20 accelerated by a predetermined acceleration voltage is emitted from the electron gun 1 serving as an electron beam source toward the sample 11 as a primary line. The electron beam 20 emitted from the electron gun 1 is first focused at the position of the diaphragm 10 by the focusing lens 2.

  In the electron beam 20 focused in this way, the electron beam 20 that has passed through the opening 10a provided in the diaphragm 10 passes through the mesh electrodes 3 to 7 constituting the electron detection means 41 and is on the subsequent stage side. The sample 11 is irradiated through the scanning coil 8 and the objective lens 9. Here, an opening (not shown) through which the electron beam 20 can pass is provided at the center of each of the mesh electrodes 3 to 7. In addition, if the electron beam 20 can pass through the opening of the mesh structure originally provided in each mesh electrode 3-7, it is not necessary to provide the opening.

  The objective lens 9 focuses the electron beam 20 that has passed through the objective lens 9 on the sample 11. As a result, an electron probe comprising the focused electron beam 20 is formed on the sample surface. As a result, the sample 11 is irradiated with the focused electron beam 20. At this time, the scanning coil 8 scans the electron beam 20 (electron probe) on the sample surface.

  The electron gun 1, the focusing lens 2, the diaphragm 10, the electron detection means 41, the scanning coil 8, and the objective lens 9 are provided in the electron beam column 42. Here, the outer surfaces of the focusing lens 2, the scanning coil 8, and the objective lens 9 are at ground potential, and the diaphragm 10 is also at ground potential. The objective lens 9 is a semi-in lens type objective lens.

  In the electron beam column 42, mesh electrodes 3 to 7 arranged between the diaphragm 10 and the scanning coil 8 are arranged at a predetermined pitch along the trajectory of the electron beam 20. Thereby, the mesh electrodes 3-7 are installed as a structure of a plurality of stages (in FIG. 1, five stages). Each mesh electrode 3-7 consists of a plate-shaped member provided with many opening which comprises a mesh. The mesh electrodes 3 to 7 have a function of separating the detected electrons 30 from the sample 11 described later for each energy band by applying different voltages. Thus, the mesh electrode group is comprised by the mesh electrodes 3-7 made into the multistage structure.

  A cylindrical ground electrode 19 is disposed around the mesh electrodes 3 to 7. A part of the ground electrode 19 is provided with a mesh portion 19a in which a plurality of holes are formed. And the electron detector 22 is arrange | positioned so that this mesh part 19a may be opposed. These mesh electrodes 3 to 7, the ground electrode 19 and the electron detector 22 constitute an electron detection means 41.

  The electron detector 22 includes light guides (light guides) 23 to 27 having a plurality of stages (five stages in FIG. 1). In each of the light guides 23 to 27, a scintillator (light emitting part) 21 is provided on the side (one end side) facing the mesh part 19 a of the ground electrode 19. The scintillator 21 is provided by applying and solidifying a liquid scintillator containing a phosphor on one end side of each of the light guides 23 to 27. In addition to the liquid scintillator, a single crystal scintillator or a plastic scintillator can also be used.

  The light guides 23 to 27 are arranged in accordance with the arrangement pitch of the mesh electrodes 3 to 7 so as to correspond to the position of the gap between the adjacent mesh electrodes and the position of the upper surface of the mesh electrode 3 located at the uppermost stage, respectively. Has been placed. That is, the light guide 27 is disposed at a position corresponding to the gap between the adjacent mesh electrodes 6 and 7, and the light guide 26 is disposed at a position corresponding to the gap between the adjacent mesh electrodes 5 and 6.

  Similarly, the light guide 25 is disposed at a position corresponding to the gap between the adjacent mesh electrodes 4 and 5, and the light guide 24 is disposed at a position corresponding to the gap between the adjacent mesh electrodes 3 and 4. A light guide 23 is disposed at a position corresponding to the upper surface of the uppermost mesh electrode 3.

  Here, a ring-shaped suction electrode 29 is disposed around the scintillator 21. A predetermined positive voltage of about 10 kV is applied to the suction electrode 29, and the detected electrons 33 to 37 that are separated for each energy band by the mesh electrodes 3 to 7 in the ground electrode 19 are passed through the mesh portion 19 a. The scintillator 21 has an action of drawing.

  In the electron detector 22, a photomultiplier tube (photoelectric conversion unit) 28 is provided on the other end side of each of the light guides 23 to 27. Here, each of the light guides 23 to 27 is provided with a reflective layer. This reflection layer constitutes a reflection surface that covers each side surface from one end side to the other end side of each of the light guides 23 to 27. Thereby, the light (scintillation light) from the scintillator 21 can be guided to the photomultiplier tube 28 by a separate path for each of the light guides 23 to 27.

  With such a configuration, each light (optical signal) emitted by the scintillator 21 based on the detected electrons 33 to 37 classified for each energy band is individually photomultiplier tube 28 by the light guides 23 to 27. Is guided to. As a result, the detected electrons 30 generated from the sample can be detected separately for each energy band.

  The photomultiplier tube 28 has a photoelectric surface divided and multi-channeled, and can individually photoelectrically convert and amplify optical signals received for each of the light guides 23 to 27. The electrical signal (detection signal) after photoelectric conversion and amplification obtained in this way is sent to the image data creation unit 18 for performing image processing for each signal.

  The image data creation unit 18 is connected to the bus line 12, creates image data of each image (scanned image) obtained based on each detection signal, and outputs the image data to the bus line 12. Each image data output from the image data creation unit 18 in this way is sent to the image data storage unit 17 via the bus line 12. The image data storage unit 17 stores the transmitted image data. A CPU 13 is connected to the bus line 12, and the CPU 13 controls the image data creation unit 18 and the image data storage unit 17 via the bus line 12.

  Here, to the electron gun 1, the focusing coil 2, the mesh electrodes 3 to 7, the scanning coil 8, and the objective lens 9, the corresponding power sources 1a to 9a are connected as shown in the figure. Each power source 1 a to 9 a is connected to the bus line 12 and is controlled by the CPU 13 through the bus line 12.

  That is, a predetermined driving power is supplied to the electron gun 1 from the power source 1a so that the electron beam 20 having a predetermined acceleration voltage is emitted. The focusing lens 2 is supplied with a predetermined driving current from the power source 2 a so as to cause a predetermined excitation for focusing the electron beam 20 at the position of the diaphragm 10. Respective drive signals are supplied from the CPU 13 to the power supply 1a and the power supply 2a through the bus line 12.

  The objective lens 9 is supplied with a predetermined driving current from a power source 9a so as to cause a predetermined excitation for focusing the electron beam 20 passing through the objective lens 9 on the sample 11. The scanning coil 8 is supplied with a predetermined scanning current for scanning the electron beam 20 focused on the sample 11 in a predetermined area from the power source 8a. Respective drive signals are supplied from the CPU 13 to the power supply 8a and the power supply 9a via the bus line 12.

  And each mesh electrode 3-7, as it is located on the upper stage side (that is, the side from the lowermost mesh electrode 7 toward the uppermost mesh electrode 3), so as to gradually approach a higher negative potential, A predetermined voltage is applied from each of the corresponding power supplies 3a to 7a. Respective drive signals are supplied from the CPU 13 to the power supplies 3a to 7a via the bus line 12.

  For example, a voltage of −50 V is applied to the lowermost mesh electrode 7 by the power supply 7a, and a voltage of −100V is applied to the upper mesh electrode 6 by the power supply 6a. Furthermore, a voltage of −200 V is applied to the middle mesh electrode 5 by the power source 5a, and a voltage of −300V is applied to the upper mesh electrode 4 from the power source 4a. A voltage of −400 V is applied to the uppermost mesh electrode 3 by the power source 3a. In this case, the voltage applied to the mesh electrodes 3 to 7 is set to a higher negative potential (high potential in the negative direction) as it goes upward.

  As another example, a voltage of +100 V is applied to the lowermost mesh electrode 7 by the power source 7a, and a voltage of + 50V is applied to the upper mesh electrode 6 by the power source 6a. Further, a ground potential (± 0V) is applied to the middle mesh electrode 5 by the power source 5a, and a voltage of −50V is applied to the upper mesh electrode 4 by the power source 4a. Then, a voltage of −100 V is applied to the uppermost mesh electrode 3 by the power source 3a. In this case, a positive potential is applied on the lower stage side, but it is set so as to become a higher potential in the minus direction through a zero potential from the lower stage side to the upper stage side.

  Here, a memory 14 is connected to the CPU 13 and data of each set voltage to the mesh electrodes 3 to 7 is stored. In addition, data of driving conditions of the electron gun 1, the focusing lens 2, the scanning coil 8, and the objective lens 9 are also stored in the memory 14. The CPU 13 reads each data corresponding to the operation of the apparatus from the memory 14 and controls each power source 1a to 9a.

  Further, a display unit 15 is connected to the bus line 12. Image data read from the image data storage unit 17 is sent to the display unit 15 under the control of the CPU 13. The display unit 15 displays an image based on the image data.

  An input unit 16 is connected to the bus line 12. The input unit 16 includes pointing means such as a mouse and key input means such as a keyboard. An operator of this apparatus can input data, specify an operation, and the like by operating the input unit 16.

  The above is the configuration of the electron beam apparatus according to the present invention. Next, the operation will be described.

  The electron beam 20 emitted from the electron gun 1 is focused by the focusing lens 2 and passes through the aperture 10 a of the diaphragm 10. The electron beam 20 that has passed through the aperture 10 a of the diaphragm 10 passes through the mesh electrodes 3 to 7 (mesh electrode group) having a multistage configuration, and is irradiated onto the sample 11 via the scanning coil 8 and the objective lens 9.

  The objective lens 9 focuses the electron beam 20 finely on the sample 11. Thereby, the focused electron beam 20 is irradiated to the sample 11. At this time, the scanning coil 8 scans the focused electron beam 20 on the sample surface.

  Thus, the detected electrons 30 including secondary electrons and reflected electrons are generated from the sample 11 irradiated with the electron beam 20. The detected electrons 30 are captured by a magnetic field generated from the semi-in-lens type objective lens 9 or an electric field associated therewith, and rise inside the objective lens 9.

  The to-be-detected electrons 30 that have risen inside the objective lens 9 pass through the scanning coil 8 and then reach the mesh electrode group composed of the mesh electrodes 3 to 7 constituting the electron detecting means 41. The detected electrons 30 are classified for each energy band in the mesh electrode group.

  That is, the detected electrons 37 that have passed through the lowermost mesh electrode 7 and do not pass through the upper mesh electrode 6 pass through the mesh portion 19a of the ground electrode 19 from the gap between the mesh electrodes 6 and 7 on the scintillator 21 side. Extracted into The detected electrons 36 that have passed through the mesh electrode 6 and do not pass through the upper mesh electrode 7 are extracted from the gap between the mesh electrodes 5 and 6 through the mesh portion 19a.

  Similarly, detected electrons 35 that have passed through the mesh electrode 5 and have not passed through the mesh electrode 4 on the upper stage are extracted from the gap between the mesh electrodes 4 and 5 through the mesh portion 19a. Further, the detected electrons 34 that have passed through the mesh electrode 4 and do not pass through the upper mesh electrode 3 are extracted from the gap between the mesh electrodes 3 and 4 through the mesh portion 19a. The detected electrons 33 that have passed through the uppermost mesh electrode 3 are extracted from the upper surface of the mesh electrode 3 through the mesh portion 19a.

  The detected electrons 33 to 37 thus extracted are in a state of being sorted for each energy band. That is, the detected electrons 37 extracted from the gap between the mesh electrodes 6 and 7 are included in the lowest energy band (hereinafter referred to as energy band E) among the detected electrons 30 incident on the mesh electrode group. . Further, the detected electrons 36 extracted from the gap between the mesh electrodes 5 and 6 are included in the range of the energy band higher than the energy band E (hereinafter referred to as energy band D).

  Similarly, the detected electrons 35 extracted from the gap between the mesh electrodes 4 and 5 are included in the energy band D (hereinafter referred to as energy band C) higher than the energy band D. Further, the detected electrons 34 extracted from the gap between the mesh electrodes 3 and 4 are included in a range of the energy band C (hereinafter referred to as energy band B) higher than the energy band C. The detected electrons 33 extracted from the upper surface of the mesh electrode 3 are included in a range of the next higher energy band (hereinafter referred to as energy band A) with respect to the energy band B. That is, each of the energy bands A to E becomes a higher energy band in order from the energy band E toward the energy band A.

  In this way, the detected electrons 33 to 37 that are separated into the energy bands A to E are caused to flow through the mesh portion 19a of the ground electrode 19 by the electric field formed by the suction electrode 29 of the electron detector 22. 21 is reached.

  The scintillator 21 generates scintillation light corresponding to each incident amount of the detected electrons 33 to 37. Each scintillation light corresponding to the incident amount of each detected electron 33 to 37 is guided to the photomultiplier tube 28 as a light signal by each light guide 23 to 27 through a separate path.

  The photomultiplier tube 28 individually photoelectrically converts and amplifies the optical signal (scintillation light) received for each of the light guides 23 to 27. Each electric signal after photoelectric conversion and amplification is sent to the image data creation unit 18 for each signal as a detection signal.

  Here, a drive signal (a signal corresponding to the scan signal) for driving the scan coil 8 is supplied from the CPU 13 to the image data creation unit 18. The image data creation unit 18 creates image data of each scanned image obtained for each of the detected electrons 33 to 37 by synchronizing the drive signal and each detection signal. Each image data is temporarily stored in the image data storage unit 17 via the bus line 12.

  Subsequently, the CPU 13 reads each image data stored in the image data storage unit 17 and sends each image data to the display unit 15. The display unit 15 displays an image based on each image data.

  Each image displayed in this manner is a scanned image detected for each detected electron 33 to 37 corresponding to each of the energy bands A to E. Therefore, the operator can observe each scanning image based on the detected electrons 33 to 37 classified for each energy band. Thereby, the sample information obtained due to the difference in energy of the detected electrons 30 generated from the sample 11 can be acquired.

  At this time, when detecting the detected electrons 37a that do not reach the lowermost mesh electrode 7 among the detected electrons 30, the light guide 27a is arranged at a position corresponding to the lower side of the mesh electrode 7 as shown in the figure. can do. The detected electrons 37a detected by the light guide 27a belong to an energy band lower than the energy band E.

  With such a configuration, for example, in the scanned image based on the detected electrons belonging to the range of the energy band corresponding to the secondary electrons having relatively low energy, the surface unevenness information of the sample can be acquired well. Further, in the scanned image based on the detected electrons belonging to the range of the energy band corresponding to the reflected electrons higher than the energy of the secondary electrons, the composition information of the sample can be acquired well.

  In addition, a scan image including new information about the sample 11 can be acquired and displayed by performing addition / subtraction of a plurality of image data in the image data creation unit 18 under the control of the CPU 13.

  In the above-described embodiment, the applied voltage is set so that the degree of the negative potential increases in accordance with the mesh electrodes 3 to 7 being positioned on the upper side, but an arbitrary voltage is applied. It is also possible to make it. For example, only detected electrons belonging to a desired energy band range can be detected.

  Further, if the electron beam barrel 42 has a sufficient length when it is designed, detection of detected electrons is performed by a plurality of electron detectors arranged in multiple stages above and below with a predetermined mesh electrode in between. It can also be done.

  Further, in the case where there is a difference in amplification factor between the outputs of the photomultiplier tubes 28 for each channel, the output of each channel is individually amplified and adjusted between the photomultiplier tube 28 and the image data creation unit 18. It is also possible to arrange possible amplifiers (not shown). Thereby, the image data creation unit 18 can optimally create image data for each channel output.

  As described above, the electron beam apparatus according to the present invention focuses the electron beam source 1 emitting the electron beam 20 accelerated by a predetermined acceleration voltage and the electron beam 20 emitted from the electron beam source 1 to the sample 11. The objective lens 9 for irradiation, the scanning coil 8 for scanning the focused electron beam 20 on the sample 11, and the object generated from the sample 11 in response to the scanning of the electron beam 20 and passed through the objective lens 9. An electron detection means 41 for detecting the detection electrons 30, the electron detection means 41 being arranged along the trajectory of the electron beam 20, and a plurality of mesh electrodes 3 to 7 to which different voltages are respectively applied; And an electron detector 22 that detects the detected electrons 34 to 37 extracted from the gaps of the mesh electrodes 3 to 7 facing each other.

  Furthermore, the electron detector 22 can detect the detected electrons 33 that are extracted through the mesh electrode 3 located at the uppermost stage.

  Here, the electron detector 22 emits light corresponding to the detected electrons 34 to 37 extracted for each of the gaps and the detected electron 33 extracted through the mesh electrode 3 positioned at the uppermost stage. Each of the light corresponding to the detected electrons 33 to 37 that are connected to the unit 21 and the light emitting unit 21 and are extracted for each gap and the detected electrons 33 that are extracted after passing through the mesh electrode 3 positioned at the uppermost stage. A light guide unit 23 to 27 that individually guides light, and a photoelectric conversion unit 28 that is connected to the light guide unit 23 to 27 and converts each light guided by the light guide unit 23 to 27 into an electrical signal individually. I have.

  Each of the light guides 23 to 27 is provided with a reflective layer corresponding to each light to be guided, and light travels in each gap where the reflective layers face each other, so that the light is individually converted into a photoelectric conversion unit. 28 is guided.

  Further, surrounding each mesh electrode 3 to 7, a ground portion 19 a surrounding the mesh electrodes 3 to 7 and having a plurality of holes formed in a portion located between each mesh electrode 3 to 7 and the electron detector 22 is provided. Electrodes are arranged.

  In the present invention, by arranging the mesh electrodes 3 to 7 in multiple stages as described above, the energy width of the detected electrons 30 can be selected and detected. That is, by controlling the applied voltages supplied to the mesh electrodes 3 to 7 by the CPU 13, the energy band of the detected electrons to be extracted can be selected.

  In addition, by providing a reflective layer inside the light guides 23 to 27, an optical signal can be separately sent to the photomultiplier tube 28 for each energy band by a single light guide as a whole. Thereby, the detection system of the to-be-detected electron 30 can be reduced in size.

  Further, since the high voltage applied to the suction electrode 29 may be the same potential on the detection surface of the light emitting unit 21 on which the detected electrons 33 to 37 are incident, the high voltage can be applied at a time in common.

  Since the photocathode of the photomultiplier tube 28 is divided into multiple channels, it is possible to simultaneously acquire images based on detected electrons having different energy bands and simultaneously display these images.

  Here, the addition and subtraction of each image can be performed simultaneously by the image data creation unit 18.

  Furthermore, since each light guide 23-27 is provided with a reflective layer, each optical signal based on each detected electron 33-37 can be separated even when the axes of the light guides 23-27 are shifted. The light can be guided to the photomultiplier tube 28 well in the path.

  Further, if a plurality of mesh portions 19a in the cylindrical ground electrode 19 are provided and the electron detectors 22 are installed corresponding to the respective locations, an image that is not affected by the detection direction is acquired. You can also.

DESCRIPTION OF SYMBOLS 1 ... Electron gun (electron beam source), 2 ... Condensing lens, 3-7 ... Mesh electrode, 8 ... Scanning coil, 9 ... Objective lens, 10 ... Diaphragm, 11 ... Sample, 12 ... Bus line, 13 ... CPU, 14 DESCRIPTION OF SYMBOLS ... Memory 15 ... Display part 16 ... Input part 17 ... Image data storage part 18 ... Image data creation part 19 ... Ground electrode, 20 ... Electron beam, 21 ... Scintillator (light emission part), 22 ... Electron detector 23-27, 27a ... light guide (light guide part), 28 ... photomultiplier tube (photoelectric conversion part), 29 ... suction electrode, 30,33-37,37a ... detected electron, 41 ... electron detection means, 42 ... electron beam column, 1a to 9a power source, 10a ... opening, 19a ... mesh portion

Claims (5)

An electron beam source that emits an electron beam accelerated by a predetermined acceleration voltage, an objective lens that focuses the electron beam emitted from the electron beam source and irradiates the sample, and the focused electron beam on the sample An electron beam apparatus comprising: a scanning coil for scanning; and an electron detecting means for detecting detected electrons generated from a sample in response to scanning of an electron beam and passing through an objective lens, the electron detecting means Are arranged along the trajectory of the electron beam, and a plurality of mesh electrodes to which different voltages are applied, and an electron detector for detecting detected electrons extracted from the gaps of the mesh electrodes facing each other for each gap. And an earth electrode that surrounds each mesh electrode and has a plurality of holes formed in a portion located between each mesh electrode and the electron detector . The electron detector emits light corresponding to the detected electrons extracted for each gap, and the light detector is connected to the light emitting section and individually outputs each light corresponding to the detected electrons extracted for each gap. The electron beam apparatus according to claim 1, further comprising: a light guide unit that guides light; and a photoelectric conversion unit that is connected to the light guide unit and converts each light guided by the light guide unit into an electrical signal. . 2. The electron beam apparatus according to claim 1, wherein the electron detector further detects electrons to be detected that are extracted through the mesh electrode positioned at the uppermost stage. The electron detector is connected to the light emitting unit and a light emitting unit that emits light according to the detected electrons extracted for each gap and the detected electrons that are extracted through the mesh electrode located at the uppermost stage, A light guide unit that individually guides light corresponding to the detected electrons extracted for each gap and the detected electrons that pass through the mesh electrode located at the uppermost stage, and is connected to the light guide unit The electron beam apparatus according to claim 3, further comprising: a photoelectric conversion unit that converts each light guided by the light guide unit into an electrical signal. The light guide unit is provided with a reflective layer corresponding to each light to be guided, and the light is individually guided by the light traveling in the gaps where the reflective layers face each other. The electron beam apparatus according to claim 2 or 4 .

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