Particle beam devices and composite beam devices

Abstract

The present invention provides a particle beam device and a composite beam device, wherein the particle beam device can selectively and appropriately switch between a charged particle beam and a neutral particle beam. The particle beam column (19) includes an ion source (41), a condenser (52), a charge exchange grid (55) and an objective lens (56). The ion source (41) generates ions. The condenser (52) switches the ion beam and the neutral beam as a particle beam irradiated to a sample (S) by switching the focus of the ion beam. The charge exchange grid (55) converts the ion beam into a neutral particle beam by neutralizing at least a portion of the ion beam. The objective lens (56) is arranged on the downstream side of the charge exchange grid (55). When the neutral particle beam is irradiated to the sample (S) as the particle beam, the objective lens (56) reduces the ion beam toward the sample (S).

Description

Technical Field

[0001] The present invention relates to a particle beam device and a composite beam device. Background Art

[0002] Traditionally, focused ion beam (FIB) systems have been used for micron-level local processing, such as in semiconductor failure analysis. For example, a charged particle beam system equipped with a FIB and a scanning electron microscope (SEM) enables observation of secondary electron images of irradiated objects such as samples and sputtering processing using a high-energy ion beam.

[0003] However, high-energy ions damage the sample surface, which hinders observation. To address this problem, FIB devices that can operate at low acceleration voltages are known, such as dedicated processing devices that use low-energy rare gas ion beams to remove surface damage. Compared to high-energy ion beams, low-energy ion beams have poor beam focusing, making it difficult to observe the state of the processed part through secondary electron images midway. Therefore, if, for example, it is necessary to repeatedly exchange samples between an ion beam-based processing device and an electron microscope to slowly optimize the finished state of the sample, the problem of increased complexity and time arises.

[0004] Conventionally, there is known a method for processing nanodevices using a neutral particle beam to suppress the generation of surface defects (see, for example, Non-Patent Document 1).

[0005] In the past, a composite beam device has been known, which includes a focused ion beam column, an electron beam column, and a neutral particle beam column. After processing a sample based on a focused ion beam, the surface of the sample is finely processed by a neutral particle beam while observing the SEM (Scanning Electron Microscope) image obtained based on the electron beam (for example, see patent document 1).

[0006] Prior art literature

[0007] Patent Literature

[0008] Patent Document 1: Japanese Patent Application Publication No. 2018-45811

[0009] Non-patent literature

[0010] Non-Patent Literature 1: Seiji Kamikawa, “Atomic-Level Surface Defect Suppression and Control of Surface Chemical Reactions Based on Neutral Particle Beam Processing,” Applied Physics, Vol. 83, No. 11, 2014, pp. 894-899 Summary of the Invention

[0011] Problems to be solved by the invention

[0012] However, the neutral particle beam column of the composite beam device described above generates a neutral particle beam from an ion beam using a neutralization mechanism located downstream of the objective lens that focuses the ion beam on the sample. However, when the neutralization mechanism is located downstream of the objective lens, in a mode for irradiating the sample with the neutral particle beam, the sample may be irradiated with the ion beam without being converted into a neutral particle beam.

[0013] An object of the present invention is to provide a particle beam device and a composite beam device capable of selectively and appropriately switching between a charged particle beam and a neutral particle beam.

[0014] Means for solving problems

[0015] In order to solve the above-mentioned problems, the particle beam device of the present invention comprises: a particle beam column, which irradiates a sample with a particle beam; a charged particle source, which generates charged particles in the above-mentioned particle beam column; a conversion unit, which converts the beam of the above-mentioned charged particles generated from the above-mentioned charged particle source in the above-mentioned particle beam column into a beam of neutral particles by neutralizing at least a part of the beam of the above-mentioned charged particles; a switching unit, which switches the beam of the above-mentioned charged particles and the beam of the above-mentioned neutral particles as the above-mentioned particle beam in the above-mentioned particle beam column; and a reducing unit, which reduces the beam of the above-mentioned charged particles toward the above-mentioned sample on the downstream side of the above-mentioned conversion unit.

[0016] In the above configuration, the switching unit may include an electrostatic lens configured to switch between the charged particle beam and the neutral particle beam as the particle beam by changing a lens strength related to a degree of focusing of the charged particle beam.

[0017] In the above configuration, the switching unit may include at least one deflector configured to switch between the charged particle beam and the neutral particle beam as the particle beam by deflecting the charged particle beam.

[0018] In the above configuration, the at least one deflector may include an upstream deflector that deflects the beam of charged particles at a position upstream of the conversion unit, thereby directing the beam of charged particles toward the conversion unit or deflecting the beam from the conversion unit.

[0019] In the above configuration, the reducing unit may include an objective lens, and a voltage may be applied to the objective lens so as to decelerate and shield the beam of the charged particles at a position downstream of the converting unit.

[0020] In the above configuration, a shielding portion for shielding the charged particle beam may be provided at a position upstream of the conversion portion in the particle beam column.

[0021] In the above configuration, an accelerating electrode for accelerating the beam of the charged particles may be provided in the particle beam column.

[0022] The composite beam device of the present invention includes any one of the particle beam devices described above and a detector for detecting secondary charged particles generated from the sample by irradiation with the charged particle beam.

[0023] In the above configuration, an electron beam column for irradiating the sample with an electron beam may be provided.

[0024] The above configuration may include a focused ion beam column for irradiating the sample with a focused ion beam.

[0025] Effects of the Invention

[0026] According to the present invention, by providing a reducing section that reduces the beam of charged particles on the downstream side of a conversion section that converts the beam of charged particles into the beam of neutral particles, it is possible to prevent the beam of charged particles that has not been neutralized from being irradiated onto the sample when the beam of neutral particles is irradiated onto the sample, and it is possible to selectively and appropriately switch the beam of charged particles and the beam of neutral particles. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 It is a diagram showing the configuration of a composite beam device in an embodiment of the present invention.

[0028] Figure 2 It is a diagram schematically showing the configuration of a particle beam device in an embodiment of the present invention.

[0029] Figure 3 This is a diagram schematically showing the configuration of a charge exchange gate of a particle beam device according to an embodiment of the present invention.

[0030] Figure 4 This is a diagram schematically showing an example of a processing process using the composite beam device in the embodiment of the present invention.

[0031] Figure 5 This is a diagram schematically showing another example of a processing process using the composite beam device in the embodiment of the present invention.

[0032] Figure 6 It is a diagram schematically showing the configuration of a charge exchange gate in a first modified example of the embodiment of the present invention.

[0033] Figure 7It is a diagram schematically showing the configuration of a charge exchange gate in a second modified example of the embodiment of the present invention.

[0034] Figure 8 It is a diagram schematically showing the configuration of a particle beam device in a third modified example of the embodiment of the present invention.

[0035] Figure 9 It is a diagram schematically showing the configuration of a particle beam device in a fourth modified example of the embodiment of the present invention.

[0036] Figure 10 This is a diagram schematically showing the configuration of an electron confinement electrode of a particle beam device in a fourth modified example of the embodiment of the present invention.

[0037] Figure 11 This is a diagram schematically showing the configuration of an electron confinement electrode of a particle beam device in a fifth modified example of the embodiment of the present invention.

[0038] Figure 12 It is a diagram schematically showing the configuration of a particle beam device in a sixth modified example of the embodiment of the present invention.

[0039] Figure 13 This is a diagram schematically showing the configuration of a charge exchange gate of a particle beam device in a sixth modified example of the embodiment of the present invention.

[0040] Figure 14 It is a diagram schematically showing the configuration of a particle beam device in a seventh modified example of the embodiment of the present invention. DETAILED DESCRIPTION

[0041] Hereinafter, a composite beam device 10 including the particle beam device 1 according to an embodiment of the present invention will be described with reference to the drawings.

[0042] (Compound Beam Device)

[0043] Figure 1 It is a diagram showing the configuration of the composite beam device 10 in the embodiment.

[0044] The composite beam device 10 includes a sample chamber 11 , a sample holder 12 , a sample stage 13 , and an electron beam column 15 , a focused ion beam column 17 , and a particle beam column 19 fixed to the sample chamber 11 .

[0045] The composite beam device 10 includes, for example, a secondary charged particle detector 21 as a detector fixed to the sample chamber 11. The composite beam device 10 includes a gas supply unit 23 for supplying gas to the surface of the sample S. The composite beam device 10 includes a control device 25 for centrally controlling the operation of the composite beam device 10 outside the sample chamber 11, and an input device 27 and a display device 29 connected to the control device 25.

[0046] It should be noted that, in the following text, the axial directions of the X-axis, Y-axis, and Z-axis, which are mutually orthogonal in three-dimensional space, are directions parallel to the respective axes. For example, the Z-axis is parallel to the vertical direction (e.g., the vertical direction) of the composite beam device 10. The X-axis and Y-axis are parallel to a reference plane (e.g., a horizontal plane) that is orthogonal to the vertical direction of the composite beam device 10.

[0047] The sample chamber 11 is formed of a pressure-resistant housing having an airtight structure capable of maintaining a desired reduced pressure state. The sample chamber 11 can be evacuated by an exhaust device (not shown) until the interior reaches a desired reduced pressure state.

[0048] The sample holder 12 holds the sample S.

[0049] The sample stage 13 is disposed inside the sample chamber 11. The sample stage 13 includes a stage 31 that supports the sample holder 12 and a stage driving mechanism 33 that three-dimensionally translates and rotates the stage 31 and the sample holder 12 integrally.

[0050] The stage drive mechanism 33, for example, causes the stage 31 to translate along each of the X-axis, Y-axis, and Z-axis. The stage drive mechanism 33, for example, causes the stage 31 to rotate at an appropriate angle around each of the predetermined rotation axis and tilt axis. The rotation axis is, for example, set relative to the stage 31, and when the stage 31 is in a predetermined reference position around the tilt axis (T axis), the rotation axis is parallel to the vertical direction of the composite beam device 10. The tilt axis is, for example, parallel to a direction orthogonal to the vertical direction of the composite beam device 10. The stage drive mechanism 33, for example, causes the stage 31 to rotate eccentrically (eucentrically) around each of the rotation axis and tilt axis. The stage drive mechanism 33 is controlled by a control signal output from the control device 25 according to the operating mode of the composite beam device 10, etc.

[0051] The electron beam column 15 irradiates an irradiation target within a predetermined irradiation area within the sample chamber 11 with an electron beam (EB). The electron beam column 15 faces the stage 31 in a first tilted direction, for example, in which an electron beam emission end 15a is tilted at a predetermined angle relative to the vertical direction of the composite beam device 10. The electron beam column 15 is fixed to the sample chamber 11 so that the optical axis of the electron beam is parallel to the first tilted direction.

[0052] The electron beam column 15 includes an electron source for generating electrons and an electron optical system for focusing and deflecting the electrons emitted from the electron source. The electron optical system includes, for example, an electromagnetic lens and a deflector. The electron source and the electron optical system are controlled by control signals output from the control device 25 based on, for example, the irradiation position and irradiation conditions of the electron beam.

[0053] The focused ion beam column 17 irradiates an irradiation target within a predetermined irradiation area within the sample chamber 11 with a focused ion beam (FIB). The focused ion beam column 17 is positioned such that, for example, an emission end 17a of the focused ion beam faces the stage 31 in the vertical direction of the composite beam device 10. The focused ion beam column 17 is fixed to the sample chamber 11 so that the optical axis of the focused ion beam is parallel to the vertical direction.

[0054] The focused ion beam column 17 includes an ion source for generating ions and an ion optical system for focusing and deflecting ions extracted from the ion source. The ion optical system includes, for example, a first electrostatic lens such as a condenser, an electrostatic deflector, and a second electrostatic lens such as an objective lens. The ion source and ion optical system are controlled by control signals output from the control device 25 based on, for example, the irradiation position and irradiation conditions of the focused ion beam. Examples of the ion source include a liquid metal ion source using liquid gallium, a plasma ion source, and a gas electric field ionization ion source.

[0055] The particle beam column 19 irradiates an irradiation target within a predetermined irradiation area within the sample chamber 11 with a particle beam (PB) of an ion beam or a neutral particle beam. The particle beam column 19 faces the stage 31 in a second inclination direction (different from the inclination direction of the electron beam column 15) in which the emission end 19a of each beam is tilted at a predetermined angle relative to the vertical direction of the composite beam device 10. The particle beam column 19 is fixed to the sample chamber 11 so that the optical axis of each beam is parallel to the second inclination direction.

[0056] The particle beam device 1 including the particle beam column 19 in the embodiment will be described later.

[0057] The optical axes of the electron beam column 15 , the focused ion beam column 17 , and the particle beam column 19 intersect at, for example, a predetermined position P above the sample stage 13 .

[0058] It should be noted that the relative arrangements of the electron beam column 15, the focused ion beam column 17, and the particle beam column 19 can be appropriately interchanged. For example, the electron beam column 15 or the particle beam column 19 can be arranged in the vertical direction, while the focused ion beam column 17 can be arranged in an inclined direction relative to the vertical direction.

[0059] The composite beam device 10 can perform imaging of the irradiated portion, various sputtering-based processing (excavation and trimming processing, etc.), and formation of deposited films, etc., by scanning the surface of the irradiation object while irradiating it with a focused ion beam or a particle beam. The composite beam device 10 can perform processing such as forming a sample piece (such as a thin sheet sample and a needle-shaped sample, etc.) for transmission observation based on a transmission electron microscope and an analysis sample piece for analysis based on an electron beam from a sample S. The composite beam device 10 can perform processing such as making the sample piece transferred to the sample piece holder into a thin film of a desired thickness suitable for transmission observation based on a transmission electron microscope. The composite beam device 10 can observe the surface of the irradiation object by scanning the surface of the irradiation object such as the sample S, the sample piece, and the needle-shaped object while irradiating it with a focused ion beam, a particle beam, or an electron beam.

[0060] The secondary charged particle detector 21 detects secondary charged particles (secondary electrons and secondary ions) generated from an irradiated object by irradiation with a focused ion beam, particle beam, or electron beam. The secondary charged particle detector 21 is connected to a control device 25, and detection signals output from the secondary charged particle detector 21 are transmitted to the control device 25.

[0061] The composite beam device 10 can be equipped with other detectors, not limited to the secondary charged particle detector 21. Other detectors are, for example, an EDS (Energy Dispersive X-ray Spectrometer) detector, a reflected electron detector, and an EBSD (Electron Back-Scattering Diffraction) detector. The EDS detector detects X-rays generated from the irradiated object by irradiation with the electron beam. The reflected electron detector detects reflected electrons reflected from the irradiated object by irradiation with the electron beam. The EBSD detector detects the backscattered diffraction pattern of electron rays generated from the irradiated object by irradiation with the electron beam. It should be noted that the secondary electron detector and the reflected electron detector for detecting secondary electrons in the secondary charged particle detector 21 can be housed in the shell of the electron beam column 15.

[0062] The gas supply unit 23 is fixed to the sample chamber 11. The gas supply unit 23 includes a gas injection unit (nozzle) positioned facing the stage 31. The gas supply unit 23 supplies etching gas and deposition gas to the irradiation target. The etching gas selectively promotes etching of the irradiation target by the focused ion beam, depending on the material of the irradiation target. The deposition gas forms a deposited film based on deposits such as metals and insulators on the surface of the irradiation target.

[0063] The gas supply unit 23 is controlled by a control signal output from the control device 25 according to the operation mode of the composite beam device 10 and the like.

[0064] The control device 25 comprehensively controls the operation of the composite beam device 10 based on, for example, a signal output from the input device 27 or a signal generated by a preset automatic operation control process.

[0065] The control device 25 is a software unit that functions by executing a predetermined program using a processor such as a CPU (Central Processing Unit). The software unit is an ECU (Electronic Control Unit) that includes a processor such as a CPU, a ROM (Read Only Memory) for storing programs, a RAM (Random Access Memory) for temporarily storing data, and electronic circuits such as a timer. At least a portion of the control device 25 may be an integrated circuit such as an LSI (Large Scale Integration).

[0066] The input device 27 is, for example, a mouse or a keyboard that outputs a signal corresponding to an input operation by the operator.

[0067] The display device 29 displays various information of the composite beam device 10 , image data generated based on the signal output from the secondary charged particle detector 21 , and a screen for performing operations such as enlarging, reducing, moving, and rotating the image data.

[0068] (Particle beam device)

[0069] Figure 2 This is a diagram showing the configuration of a particle beam device 1 including a particle beam column 19 in the embodiment.

[0070] The particle beam device 1 is, for example, a gas ion beam device. A particle beam column 19 is fixed to the sample chamber 11. The particle beam column 19 includes an ion source 41 and an ion optical system 42. The ion source 41 and the ion optical system 42 are controlled by control signals output from the control device 25 based on the irradiation position and irradiation conditions of the particle beam.

[0071] The ion source 41 generates ions. The ion source 41 is, for example, a PIG (Penning Ionization Gauge) type ion source, and generates ions of a rare gas such as argon (Ar) or another gas such as oxygen.

[0072] For example, the ion source 41 can operate within an acceleration voltage range of 200 V to 5 kV. At an acceleration voltage of 1 kV, a particle flux equivalent to 20 nA can be generated as an ion beam and a particle flux equivalent to 5 nA as a neutral particle beam on the sample S. The image resolution of a secondary electron image based on an ion beam with an acceleration voltage of 1 kV is approximately 50 microns.

[0073] The ion optical system 42 focuses, deflects, and neutralizes ions extracted from the ion source 41. The ion optical system 42 includes, for example, an extraction electrode 51, a condenser 52, a blanker 53, a blanking aperture 54, a charge exchange grid 55, an objective lens 56, and a deflector 57, which are arranged in this order from the ion source 41 side toward the emission end 19a side of the particle beam column 19 (i.e., the sample S side).

[0074] The extraction electrode 51 extracts ions from the ion source 41 by generating an electric field between the extraction electrode 51 and the ion source 41. The voltage applied to the extraction electrode 51 is controlled according to, for example, the acceleration voltage of the ion beam.

[0075] The condenser 52 is, for example, an electrostatic lens having three electrodes arranged along the optical axis. The condenser 52 focuses the ion beam extracted from the ion source 41 via the extraction electrode 51. Depending on whether the particle beam column 19 is in a mode of irradiating the sample S with the ion beam as a particle beam or in a mode of irradiating the sample S with a neutral particle beam as a particle beam, the condenser 52 changes the lens intensity related to the degree of focusing of the ion beam. For example, when the particle beam column 19 is in a mode of irradiating the sample S with a neutral particle beam as a particle beam, the condenser 52 adjusts the applied voltage so that the ion beam is further expanded in the charge exchange gate 55 described later compared to the mode of irradiating the sample S with the ion beam.

[0076] The blanker 53 includes, for example, a pair of electrodes (blanking electrodes) disposed opposite each other with the optical axis intersecting the direction of travel of the ion beam. The blanker 53 switches between shielding the ion beam and shielding the ion beam. For example, the blanker 53 shields the ion beam by deflecting it so that it collides with the blanking aperture 54, and releases the shielding by not deflecting the ion beam.

[0077] Figure 3 1 is a diagram schematically showing the configuration of the charge exchange gate 55 of the particle beam device 1 according to the embodiment.

[0078] The charge exchange gate 55 is formed of a metal or the like having a predetermined shape that allows at least a portion of the ion beam to collide with the ion beam at least once without shielding the ion beam. The charge exchange gate 55 has, for example, a cylindrical shape with a central axis coaxial with the optical axis of the ion beam. The charge exchange gate 55 has a concavely curved inner circumferential surface 55c, the inner diameter of which gradually decreases from the axial ends 55a toward the axial center 55b.

[0079] The charge exchange gate 55 absorbs electrons from a portion of the ions incident on the inner peripheral surface 55c at a shallow angle, thereby performing charge exchange and converting the ions into neutral particles. Figure 3 In the example shown, the neutral particle beam NB neutralized by charge exchange among the ion beam IB incident on the charge exchange gate 55 is emitted from the charge exchange gate 55 toward the objective lens 56 together with the ion beam IB without charge exchange.

[0080] like Figure 2 As shown, the objective lens 56 is, for example, an electrostatic lens including three electrodes arranged along the optical axis. The objective lens 56 includes, for example, a deceleration electrode as a center electrode to which a voltage for forming an electric field for decelerating the ion beam is applied.

[0081] When the particle beam column 19 is in a mode in which the ion beam is irradiated onto the sample S as a particle beam, the objective lens 56 focuses the ion beam onto the sample S. When the particle beam column 19 is in a mode in which the neutral particle beam is irradiated onto the sample S as a particle beam, the objective lens 56 applies a voltage equal to or greater than the kinetic energy of the ions to the deceleration electrode, thereby suppressing the passage of the ion beam. In other words, the voltage is applied to the objective lens 56 to decelerate the ion beam and thereby shield it.

[0082] The deflector 57 includes, for example, two or more electrodes arranged in a cylindrical shape around the optical axis of the ion beam. The deflector 57 scans the irradiation position of the ion beam on the sample S. The deflector 57 performs raster scanning on a rectangular area on the surface of the sample S by applying a deflection voltage for two-dimensional scanning, for example.

[0083] (Processing Technology)

[0084] Figure 4 It is a diagram schematically showing an example of a processing process using the composite beam device 10 in the embodiment.

[0085] For example, when processing an insulating material sample S, the sample S is first irradiated with an ion beam from the particle beam column 19. Based on the scanning electron image of secondary electrons detected by the secondary charged particle detector 21, a target processing point A2 within the scanning range A1 is searched for. Next, the sample S is irradiated with a neutral particle beam from the particle beam column 19 to process the processing point A2.

[0086] For example, when processing point A2 using an ion beam, the ion beam may be deformed due to charging caused by long-term processing and the effects of electromagnetic fields, resulting in a processing point A3 that is not the desired shape. In contrast, processing using a neutral particle beam allows for high-precision processing of the target processing point A2.

[0087] Figure 5 This is a diagram schematically showing another example of a processing process using the particle beam device according to the embodiment.

[0088] For example, when processing a sample S using both the electron beam column 15 and the particle beam column 19, the sample S is first irradiated with an electron beam from the electron beam column 15. Based on the scanning electron image of the secondary electrons detected by the secondary charged particle detector 21, a processing point A2, which is the target, is searched for within the scanning range A1. Next, the sample S is irradiated with a neutral particle beam from the particle beam column 19 to process the processing point A2. It should be noted that observation of the processing point A2 based on the scanning electron image and processing of the processing point A2 using the neutral particle beam can be performed simultaneously. Processing using the neutral particle beam allows for high-precision processing without being affected by the electromagnetic field generated by the electron beam column 15.

[0089] As described above, the composite beam device 10 of the embodiment includes the objective lens 56 that reduces the ion beam on the downstream side of the charge exchange gate 55, thereby preventing the sample S from being irradiated with the non-neutralized ion beam when the sample S is irradiated with the neutral particle beam. This makes it possible to selectively and appropriately switch between the ion beam and the neutral particle beam.

[0090] When switching between an ion beam and a neutral particle beam as the particle beam irradiated to the sample S, the neutralization efficiency of the ion beam in the charge exchange gate 55 can be appropriately switched by having a condenser mirror 52 that switches the focus of the ion beam by changing the lens intensity related to the focusing degree of the ion beam.

[0091] By providing the blanker 53 and the blanking aperture 54 for shielding the ion beam on the upstream side of the charge exchange gate 55 , when the sample S is irradiated with either an ion beam or a neutral particle beam as a particle beam, irradiation can be easily stopped.

[0092] The particle beam column 19 can perform either position detection of a secondary electron scan image using the ion beam or processing using the neutral particle beam by selectively using the ion beam and the neutral particle beam.

[0093] By performing neutralization by charge exchange in the charge exchange grid 55 inside the particle beam column 19 , reactive ions such as oxygen can also be used, and a more compact optical system can be formed compared to, for example, gas charge exchange.

[0094] (Variation)

[0095] Hereinafter, a modification of the embodiment will be described. It should be noted that the same reference numerals are used for the same parts as those in the above embodiment, and the description thereof will be omitted or simplified.

[0096] In the above embodiment, the charge exchange gate 55 has a cylindrical shape with a concave inner surface 55c, but the charge exchange gate 55 is not limited thereto and may have other shapes. The shape of the surface of the charge exchange gate 55 that exchanges charge through collision with ions may be, for example, a shape required to achieve a desired neutral particle beam shape and neutral particle density.

[0097] Figure 6 It is a diagram schematically showing the configuration of a charge exchange gate 55A in a first modification of the embodiment.

[0098] The outer shape of the charge exchange gate 55A in the first modification is, for example, a multi-cylindrical shape based on two or more cylindrical bodies 61 of different sizes having a central axis coaxial with the optical axis of the ion beam. The two or more cylindrical bodies 61 are, for example, a first cylindrical body 61(1), a second cylindrical body 61(2), a third cylindrical body 61(3), and a fourth cylindrical body 61(4).

[0099] The charge exchange gate 55A in the first modification absorbs electrons from a portion of the ions incident on the inner peripheral surface of each cylindrical body 61 at a shallow angle, thereby performing charge exchange and converting the ions into neutral particles. Figure 6 In the example shown, the neutral particle beam NB in ​​the ion beam IB incident on the inside of the charge exchange gate 55A, which is neutralized by charge exchange on the inner surface of each cylindrical body 61, is emitted from the inside of the charge exchange gate 55A toward the objective lens 56 together with the ion beam IB that has not been charge exchanged.

[0100] According to the first modification, the neutralization efficiency can be improved by increasing the number of cylindrical bodies 61 that collide with the ion beam.

[0101] Figure 7 It is a diagram schematically showing the configuration of a charge exchange gate 55B in a second modification of the embodiment.

[0102] The charge exchange gate 55B in the second modified example has a cylindrical shape, for example, having a central axis coaxial with the optical axis of the ion beam. The charge exchange gate 55B has a tapered, concavely curved inner circumference 62c whose inner diameter gradually decreases from an incident-side end 62a toward an exit-side end 62b in the axial direction of the central axis.

[0103] The charge exchange gate 55B in the second modification example absorbs electrons from a portion of the ions incident on the inner peripheral surface 62c at a shallow angle, thereby performing charge exchange and converting the ions into neutral particles. Figure 7 In the example shown, the neutral particle beam NB, which is neutralized by multiple charge exchanges on the inner surface 62c, in the ion beam IB incident on the inside of the charge exchange gate 55B is emitted from the inside of the charge exchange gate 55B toward the objective lens 56 together with the ion beam IB that has not been charge exchanged.

[0104] According to the second modification, the neutralization efficiency can be improved by increasing the number of collisions with the ion beam according to the shape of the charge exchange gate 55B.

[0105] In the above-described embodiment, the particle beam column 19 may include an accelerating electrode and the like for accelerating the ion beam.

[0106] Figure 8 It is a diagram schematically showing the configuration of a particle beam apparatus 1A in a third modified example of the embodiment.

[0107] The particle beam column 19A of the particle beam device 1A in the third modification includes an ion source 41 and an ion optical system 42A. The ion optical system 42A further includes an accelerating electrode 63 in addition to the ion optical system 42 in the above-described embodiment, for example.

[0108] The accelerating electrode 63 is disposed, for example, between the condenser lens 52 and the objective lens 56, and surrounds the blanker 53, the blanking aperture 54, and the charge exchange grid 55. The accelerating electrode 63 increases the kinetic energy of the ion beam, thereby reducing aberrations of the ion beam and the neutral particle beam.

[0109] According to the third modification, by providing the accelerating electrode 63 that accelerates the ion beam, the aberration between the ion beam and the neutral particle beam can be reduced, and the accuracy of processing or observation of the sample S can be improved.

[0110] In the above-described embodiment, the particle beam column 19 may include an electron confinement electrode and an electron generating device for increasing the neutralization efficiency of the charge exchange grid 55 .

[0111] Figure 9 It is a diagram schematically showing the configuration of a particle beam apparatus 1B in a fourth modified example of the embodiment. Figure 10It is a diagram schematically showing the configuration of the electron confinement electrode 64 in the fourth modified example of the embodiment.

[0112] like Figure 9 As shown, a particle beam column 19B of a particle beam device 1B in the fourth modification includes an ion source 41 and an ion optical system 42B. The ion optical system 42B further includes an electron confinement electrode 64 and an electron generator 65 in addition to the ion optical system 42 of the above embodiment.

[0113] like Figure 10 As shown, the electron confinement electrode 64 is configured to cover the charge exchange grid 55 without shielding the ion beam. The electron confinement electrode 64 generates an electric field by applying a voltage to confine the secondary electrons generated in the charge exchange grid 55 and the primary electrons generated in the electron generating device 65 within the charge exchange grid 55. Figure 10 In the example shown, the orbit EO of the secondary electrons generated in the charge exchange gate 55 stays inside the charge exchange gate 55 .

[0114] The electron confinement electrode 64 promotes neutralization of the ion beam by charge exchange by confining electrons inside the charge exchange grid 55 .

[0115] like Figure 9 As shown, the electron generator 65 supplies primary electrons to the charge exchange gate 55. The electron generator 65 is, for example, a thermal electron source including a filament that emits thermal electrons by heating. The electron generator 65 is, for example, disposed between the charge exchange gate 55 and the objective lens 56.

[0116] According to the fourth modification, the neutralization efficiency of the charge exchange gate 55 can be improved by providing the electron confinement electrode 64 and the electron generating device 65 .

[0117] In the fourth modification, the electron generating device 65 is disposed outside the electron confinement electrode 64 . However, the present invention is not limited thereto, and the electron generating device 65 may be disposed inside the electron confinement electrode 64 .

[0118] Figure 11 This is a diagram schematically showing the configuration of the electron confinement electrode 64 in the fifth modified example of the embodiment.

[0119] The electron generating device 65 in the fifth modification is arranged inside the electron confinement electrode 64. Figure 11 In the example shown, the equipotential line EL is formed between the electron confinement electrode 64 and the charge exchange gate 55, so that the orbits EO of the secondary electrons generated in the charge exchange gate 55 and the primary electrons generated in the electron generating device 65 respectively stay inside the charge exchange gate 55.

[0120] According to the fifth modification, by providing the electron generating device 65 disposed inside the electron confinement electrode 64 , the neutralization efficiency of the charge exchange gate 55 can be improved.

[0121] It should be noted that while the fourth and fifth modifications described above include both the electron confinement electrode 64 and the electron generating device 65, the present invention is not limited thereto and may include only one of them. Furthermore, when the electron confinement electrode 64 is omitted, a voltage can be directly applied to the charge exchange gate 55 to form an electric field that confines the secondary electrons generated in the charge exchange gate 55 and the primary electrons generated in the electron generating device 65 within the charge exchange gate 55.

[0122] In the above embodiment, the central axis of the charge exchange gate 55 is coaxial with the optical axis of the ion beam, but the present invention is not limited thereto. The central axis of the charge exchange gate 55 may also be arranged offset from the optical axis of the ion beam.

[0123] Figure 12 It is a diagram schematically showing the configuration of a particle beam apparatus 1C in a sixth modification of the embodiment. Figure 13 This is a diagram schematically showing the configuration of a charge exchange gate 55C of a particle beam apparatus 1C in a sixth modification of the embodiment.

[0124] like Figure 12 As shown, a particle beam column 19C of a particle beam device 1C in the sixth modification includes an ion source 41 and an ion optical system 42C. The ion optical system 42C further includes an upper deflector 66 in addition to the charge exchange grid 55C in place of the charge exchange grid 55 in the ion optical system 42 of the above embodiment.

[0125] The charge exchange gate 55C of the sixth modification is arranged to be offset from the optical axis of the ion beam so as to prevent the ion beam from entering when the particle beam column 19C irradiates the sample S with an ion beam as the particle beam mode.

[0126] like Figure 13 As shown, the outer shape of the charge exchange gate 55C in the sixth modification is, for example, an aggregate of two or more flat plates 67 parallel to the optical axis of the ion beam. The two or more flat plates 67 are, for example, a first flat plate 67(1), a second flat plate 67(2), a third flat plate 67(3), and a fourth flat plate 67(4) arranged in parallel in sequence with a predetermined interval in the thickness direction.

[0127] The charge exchange gate 55C in the sixth modification example absorbs electrons from a portion of the ions incident on the surface of each plate 67 at a shallow angle, thereby performing charge exchange and converting the ions into neutral particles. Figure 13In the example shown, the neutral particle beam NB, which is neutralized by charge exchange on the surfaces of the plates 67 , among the ion beam IB incident on the charge exchange gate 55C, is reflected from the charge exchange gate 55C toward the objective lens 56 .

[0128] like Figure 12 As shown, the upper deflector 66 includes, for example, two or more electrodes arranged in a cylindrical shape around the optical axis of the ion beam. The upper deflector 66 is arranged upstream of the charge exchange gate 55C, for example, between the blanking aperture 54 and the charge exchange gate 55C. When the particle beam column 19C is in a particle beam mode where the sample S is irradiated with an ion beam, for example, no deflection voltage is applied to the upper deflector 66, thereby not deflecting the ion beam but guiding it toward the outside of the charge exchange gate 55C. When the particle beam column 19C is in a particle beam mode where the sample S is irradiated with a neutral particle beam, for example, a deflection voltage is applied to the upper deflector 66, thereby deflecting the ion beam and guiding it toward the charge exchange gate 55C.

[0129] The upper deflector 66 can adjust the deflection amount of the ion beam according to the applied deflection voltage, thereby changing the desired neutralization efficiency in the charge exchange gate 55C and the desired irradiation position of the neutral particle beam in the sample S, etc.

[0130] In the sixth modification, when switching between the ion beam and the neutral particle beam as the particle beam, it is not necessary to switch the focus of the ion beam by the condenser mirror 52 .

[0131] According to the sixth variation, by providing an upper deflector 66 that switches the deflection of the ion beam when switching between an ion beam and a neutral particle beam as the particle beam irradiated to the sample S, the neutralization efficiency of the ion beam in the charge exchange gate 55 can be appropriately switched.

[0132] In the above embodiment, when the particle beam column 19 irradiates the sample S with an ion beam as the particle beam mode, the ion beam is also incident on the charge exchange gate 55 . However, the present invention is not limited thereto and the ion beam may be guided to the outside of the charge exchange gate 55 .

[0133] Figure 14 It is a diagram schematically showing the configuration of a particle beam device 1D in a seventh modification of the embodiment.

[0134] The particle beam column 19D of the particle beam device 1D in the seventh modification includes an ion source 41 and an ion optical system 42D. The ion optical system 42D further includes an upper deflector 66 and a middle deflector 68 in addition to the ion optical system 42 of the above embodiment.

[0135] The upper deflector 66 and the middle deflector 68 each include, for example, two or more electrodes arranged in a cylindrical shape around the optical axis of the ion beam. The upper deflector 66 and the middle deflector 68 are, for example, arranged between the blanking aperture 54 and the charge exchange grid 55C. The upper deflector 66 and the middle deflector 68 are arranged in this order from the ion source 41 side toward the emission end 19a side of the particle beam column 19D (i.e., the sample S side).

[0136] When the particle beam column 19D irradiates the sample S with an ion beam as a particle beam mode, for example, by applying a deflection voltage, the upper deflector 66 and the middle deflector 68 deflect the ion beam and guide it toward the outside of the charge exchange grid 55. When the particle beam column 19C irradiates the sample S with a neutral particle beam as a particle beam mode, for example, by not applying a deflection voltage, the upper deflector 66 and the middle deflector 68 do not deflect the ion beam and guide it toward the charge exchange grid 55.

[0137] According to the 7th variant, by having an upper deflector 66 and a middle deflector 68 for switching the deflection of the ion beam when switching the ion beam and the neutral particle beam as the particle beam irradiated to the sample S, the neutralization efficiency of the ion beam in the charge exchange gate 55 can be appropriately switched.

[0138] In order to ensure that the composite beam device 10 irradiates the sample S at the same point, the particle beam column 19 may include a mechanism for adjusting the position of the particle beam. For example, the particle beam column 19 may include a deflector positioned upstream of the charge exchange gate 55 to fine-tune the angle of incidence of the ion beam, or it may include a mechanism that mechanically moves the entire particle beam column 19. For example, the deflector positioned upstream of the charge exchange gate 55 is used to adjust the horizontal direction and the vertical direction on the sample S. It may be used in conjunction with the upper deflector 66 in the sixth and seventh variations described above, or it may be configured separately from the upper deflector 66.

[0139] In the above embodiment, the composite beam device 10 includes the electron beam column 15 , the focused ion beam column 17 , and the particle beam column 19 , but is not limited thereto. For example, the composite beam device 10 may be a combination of the electron beam column 15 and the particle beam column 19 .

[0140] The embodiments of the present invention are provided as examples and are not intended to limit the scope of the invention. These embodiments may be implemented in various other ways and may be omitted, replaced, or modified without departing from the gist of the invention. These embodiments and their variations are included within the scope and gist of the invention and are also included within the invention described in the claims and their equivalents.

[0141] Explanation of symbols

[0142] 1, 1A, 1B, 1C, 1D…particle beam device, 10…composite beam device, 11…sample chamber, 12…sample holder, 13…sample stage, 15…electron beam column, 17…focused ion beam column, 19, 19A, 19B, 19C, 19D…particle beam column, 21…secondary charged particle detector (detector), 23…gas supply unit, 25…control device, 27…input device, 29…display device, 41…ion source (charged particle source), 42, 42A, 42B, 42C, 42D…ion optical system, 51 …extraction electrode, 52…condenser (switching part, electrostatic lens), 53…blanker (shielding part), 54…blanking aperture (shielding part), 55, 55A, 55B, 55C…charge exchange gate (conversion part), 56…objective lens (reduction part), 57…deflector, 63…accelerating electrode, 64…electron confinement electrode, 65…electron generating device, 66…upper deflector (switching part, deflector, upstream side deflector), 68…middle deflector (switching part, deflector), S…sample, PB…particle beam, IB…ion beam, NB…neutral particle beam

Claims

1. A particle beam device, characterized in that The particle beam device comprises: a particle beam column for irradiating a particle beam onto a sample; a charged particle source that generates charged particles within the particle beam column; a conversion unit that neutralizes at least a portion of the charged particle beam generated from the charged particle source within the particle beam column, thereby converting the charged particle beam into a neutral particle beam; a switching unit that switches between the charged particle beam and the neutral particle beam as the particle beam in the particle beam column; and a reducing section that reduces the beam of charged particles toward the sample on a downstream side of the converting section, The reducing unit includes an objective lens, and a voltage is applied to the objective lens so as to decelerate and shield the beam of the charged particles at a position downstream of the converting unit.

2. The particle beam device according to claim 1, wherein The switching unit includes an electrostatic lens configured to switch between the charged particle beam and the neutral particle beam as the particle beam by changing a lens strength that is correlated with a degree of focusing of the charged particle beam.

3. The particle beam device according to claim 1, wherein The switching unit includes at least one deflector configured to switch between the charged particle beam and the neutral particle beam as the particle beam by deflecting the charged particle beam. The at least one deflector includes an upstream deflector that deflects the beam of charged particles at a position upstream of the conversion unit, thereby guiding the beam of charged particles toward the conversion unit or deflecting the beam from the conversion unit.

4. The particle beam device according to any one of claims 1 to 3, wherein The particle beam device includes a shielding portion that shields the charged particle beam at a position upstream of the conversion portion in the particle beam column.

5. The particle beam device according to claim 4, characterized in that The particle beam device includes an accelerating electrode that accelerates the beam of the charged particles in the particle beam column.

6. A composite beam device, characterized in that: The composite beam device includes the particle beam device according to any one of claims 1 to 5 and a detector for detecting secondary charged particles generated from the sample by irradiation with the charged particle beam.

7. The composite beam device according to claim 6, characterized in that The composite beam device includes an electron beam column for irradiating the sample with an electron beam.

8. The composite beam device according to claim 6, wherein: The composite beam device includes a focused ion beam column for irradiating the sample with a focused ion beam.

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