Corrector transfer optics for a lorentz electron microscope

Abstract

Disclosed herein are charged particle microscopes with optimized performance across multiple modes of operation. More specifically, the present disclosure includes improved charged particle microscopes that increase and / or optimize the performance of the microscope in both standard and Lorentzian modes of operation. The charged particle microscopes include an additional transfer lens between the corrector and the conventional transfer lens, which allows for flexible optimization of performance in the standard and Lorentzian modes of operation. For example, in the Lorentzian mode of operation, the improved charged particle microscopes according to the present disclosure can be used to tune C5 aberrations while having little to no impact on defocus and / or C S aberrations. Additionally, the additional transfer lens provides additional degrees of freedom with which to zero defocus and total C S and C5 according to the present disclosure.

Description

Background Technology

[0001] Microscope magnification and resolution need to be continuously improved so that scientists and engineers can continue to explore and develop technologies at increasingly smaller scales. To achieve this, microscope components are constantly being improved to enhance microscope performance (i.e., increase resolution, increase magnification, reduce aberrations, etc.). However, when a microscope can operate in more than one mode, a change in one microscope component can improve microscope performance in the first mode while degrading it in a second, different mode. Therefore, the development of microscopes that improve performance across multiple operating modes and / or allow for optimization of microscope performance is desired. Summary of the Invention

[0002] According to this disclosure, a charged particle microscope with optimized performance in both standard operating mode and Lorentz operating mode includes a charged particle source configured to emit a beam of charged particles toward a sample; a sample holder configured to hold the sample; a corrector for correcting axial aberrations (and / or other aberrations, such as off-axis coma); a Lorentz lens located between the corrector and the sample holder; and an objective lens located between the Lorentz lens and the sample holder. The charged particle microscope is characterized by including a first transfer lens located between the corrector and the Lorentz lens, and a second transfer lens located between the corrector and the first transfer lens. The charged particle microscope is configured to switch between a first configuration operating in standard operating mode and a second configuration operating in Lorentz mode.

[0003] According to this disclosure, a method for operating such a charged particle microscope (configured to operate in standard operating mode when in a first configuration and in Lorentz operating mode when in a second configuration) includes: emitting a beam of charged particles toward a sample via a charged particle source, and using a corrector to correct axial (and in some cases off-axis) aberrations. When the charged particle microscope is operated in Lorentz operating mode (Lorentz STEM or Lorentz TEM), the method includes using a first transfer lens and a second transfer lens to optimally tune defocus, C s And C5. In addition, when the microscope is operated in standard operating mode (STEM or TEM), the method includes focusing the charged particle beam with a second transfer lens located between the corrector and the first transfer lens, such that the second transfer lens assists the first transfer lens in imaging the exit plane of the corrector at or near the objective, in order to minimize the combined aberration C5 (axial 5th order spherical aberration). Attached Figure Description

[0004] Please refer to the accompanying drawings for a detailed description. In the drawings, the leftmost digit (one or more) of the reference numerals indicates the drawing in which the reference numeral first appears. The same reference numerals in different drawings indicate similar or identical items.

[0005] Figure 1 The illustration shows an example charged particle microscope system for examining samples, which has optimized performance in multiple operating modes.

[0006] Figure 2 It is a collection of diagrams illustrating the optical behavior of a corrector-transfer optics in a charged particle system with a corrector and one or more lenses.

[0007] Figure 3 An example charged particle microscope system is illustrated, which is a TEM system capable of operating in both standard and Lorentz operating modes.

[0008] Figure 4 The sampling process of examining, depositing, grinding, and / or extracting sample components using a charged particle microscopy system with optimized performance in multiple operating modes is described.

[0009] Figure 5 A diagram illustrating the optical performance of a system with a single transfer lens arrangement operating in Lorentz operation mode.

[0010] Figure 6 A diagram illustrating the optical performance of a system with a single transfer lens arrangement operating in Lorentz operation mode.

[0011] Figure 7 A diagram illustrating the optical performance of a system with a multi-transfer lens arrangement operating in Lorentz operation mode.

[0012] Throughout the various views of the accompanying drawings, similar reference numerals denote corresponding parts. Generally, in the drawings, elements that may be included in a given example are illustrated with solid lines, while elements that are optional for a given example are illustrated with dashed lines. However, elements illustrated with solid lines are not essential for all examples of this disclosure, and elements shown with solid lines may be omitted from certain examples without departing from the scope of this disclosure. Detailed Implementation

[0013] This document discloses a charged particle microscope with optimized performance across multiple operating modes. More specifically, this disclosure includes an improved charged particle microscope that enhances and / or optimizes microscope performance in both standard and Lorentz operating modes. The charged particle microscope includes an additional transfer lens between the corrector and the conventional transfer lens, which allows for flexible performance optimization in both standard and Lorentz operating modes. For example, in Lorentz operating mode, the improved charged particle microscope according to this disclosure can be used to tune C5 aberrations with a first transfer lens while having minimal impact on defocus and / or C… SAberrations. Additionally, the inclusion of an extra transfer lens provides the charged particle microscope disclosed herein with additional degrees of freedom to address defocusing and total C. S And C5 is reset to zero.

[0014] Figure 1 This illustration shows an example charged particle microscopy system (one or more) 100 for examining the components of sample 102, which has optimized performance in a variety of operating modes. The example charged particle microscopy system (one or more) 100 may include an electron microscope (EM) setup or an electron lithography setup configured to irradiate and / or otherwise illuminate the sample 102 with a charged particle beam 104 (typically an electron beam or ion beam). In various embodiments, the charged particle microscopy system 100 may be or include one or more different types of EMs and / or charged particle microscopes, such as, but not limited to, scanning electron microscopes (SEM), scanning transmission electron microscopes (STEM), transmission electron microscopes (TEM), charged particle microscopes (CPM), dual-beam microscope systems, etc. Furthermore, in some embodiments, a TEM can also operate as a STEM.

[0015] Figure 1 One or more example charged particle microscopy systems 100 are shown as STEM systems 106 capable of operating in both standard and Lorentz operating modes. The standard operating mode corresponds to irradiating a sample 102 with a beam of charged particles 104 for the examination, deposition, grinding, and / or extraction of components from the sample 102. The Lorentz operating mode corresponds to an imaging mode in which magnetic contrast is generated based on the deflection experienced by charged particles 104 passing through a magnetically inductive region within the sample 102. Figure 1 As shown, the path of the charged particle beam 104 changes according to the operating mode of the example charged particle microscope system (one or more) 100. For example, Figure 1 It is shown that when the example charged particle microscope system (one or more) 100 is operating in standard operating mode, the charged particle beam 104 follows beam path 104(a), while when the example charged particle microscope system (one or more) 100 is operating in Lorentz operating mode, the charged particle beam follows beam path 104(b). Figure 1 The path of axial electrons 105 scattered by sample 102 as charged particles 104 are incident on sample 102 is also illustrated.

[0016] Example charged particle microscopy system (one or more) 100 includes a charged particle source 108 (e.g., a thermionic source, a Schottky emission source, a field emission source, a liquid metal ion source, a plasma source, etc.) that emits a charged particle beam 104 along an emission axis 110 toward an accelerator lens 112. The emission axis 110 is an axis extending along the length of the example charged particle microscopy system (one or more) 100 from the charged particle source 108 and passing through the central axis of the sample 102. For ease of understanding, the charged particle beam 104... Figure 1-3 In Figures 5 and 6, the beam is illustrated as a pencil beam. However, those skilled in the art will understand that when the pencil beam passes through the example charged particle microscope system(s) 100, the pencil beam corresponds to the outer ray of the beam cone of the charged particle beam 104 (i.e., the outer diameter of the charged particle beam 104). In other words, Figure 1 The diagram 104 illustrates the axial rays of a charged particle beam.

[0017] The accelerator lens 112 accelerates / decelerates, focuses, and / or directs the charged particle beam 104 toward the focusing column 114. The focusing column 114 focuses the charged particle beam 104 so that it is incident on the sample 102. Additionally, the focusing column 114 corrects and / or tunes aberrations (e.g., geometric aberrations, chromatic aberrations) of the charged particle beam 104. Figure 1 In the illustration, the focusing column 114 is shown as an arrangement including a corrector 116 and a plurality of lenses 118. The corrector 116 is an optical component for correcting axial aberrations of the charged particle beam 104. In various embodiments, the corrector 116 may be a hexapole corrector, which may be a Rose (-type), S-CORR corrector, or Crewe (-type) hexapole corrector, or a tetrapole-octapole corrector, or any other type, or may be configured to correct geometric and / or chromatic aberrations within one or more of the example charged particle microscope systems 100. In this disclosure, embodiments in which the charged particle beam 104 exits the corrector 116 are described, with the path of the charged particle beam being (substantially) parallel to the emission axis 110. However, those skilled in the art will understand that this disclosure is extendable to non-parallel cases (e.g., where the corrector 116 creates a beam crossing point at or near its exit plane).

[0018] exist Figure 1In the diagram, the focusing column 114 is also illustrated as an arrangement including a plurality of lenses 118, including an objective lens 120, a Lorentz lens 122, a first transfer lens 124, and a second transfer lens 126. The objective lens 120 is an optical device for focusing a charged particle beam 104 onto a point on a sample 102. The objective lens 120 may comprise a monopolar lens, a magnetic-electrostatic compound lens, an electrostatic detector objective lens, or another type of objective lens. In some embodiments, the objective lens 120 is closed when the example charged particle microscope system 100 is operating in Lorentz mode. In such embodiments, the Lorentz lens 122 functions as an objective lens and focuses the charged particle beam 104 onto the sample. The Lorentz lens 122 is an optical lens that causes the divergent portion of the charged particle beam 104 from the first transfer lens 124 to become a converging beam and / or a smaller diverging beam. When the example charged particle microscope is operating in standard mode, the Lorentz 122 acts as an additional transfer lens. For example, Figure 1 The illustration shows a Lorentz lens 122 that causes the divergent portion of the charged particle beam 104 to (a) become a smaller divergent beam when the example charged particle microscope system 100 is operated in standard operating mode, and (b) become a converging beam when the example charged particle microscope system 100 is operated in Lorentz mode.

[0019] Figure 1 The illustration also shows an arrangement of multiple lenses 118, including multiple transfer lenses. Specifically, Figure 1 The illustration shows an arrangement of multiple lenses 118, including a first transfer lens 124 and a second transfer lens 126. Traditionally, similar microscope systems contain only a single transfer lens, which is positioned and / or otherwise configured in its optical properties to optimize the performance of the microscope system during a single operating mode. While such single transfer lens arrangements can be designed to perform well in Lorentz mode, this configuration can impair system performance when operating in standard operating modes.

[0020] More specifically, while current configurations of the correctors and / or monochromators can reduce energy spread, suppress chromatic aberration, and correct geometric aberrations up to order 5, in such current configurations, the position of the single transfer lens is only optimal for standard operating modes. That is, current single transfer lens configurations compromise performance in Lorentz operating modes and / or are not optimal for Lorentz operating modes. For example, for the ideal performance of the charged particle microscope system 100, the C5 aberration must be sufficiently small, and preferably negative, so that it can be combined with C... S Aberrations and defocus are used to compensate for C7 aberrations.

[0021] Furthermore, in existing microscope systems, it is desirable that the main hexapole excitation level of the current corrector 116 be very high in order to reduce the C generated within the microscope system. CAnd thermomagnetic field noise (i.e., Johnson noise). However, in these existing systems, this increase in principal hexapole excitation also produces a large C5 combined aberration that suppresses the performance of the microscope system. While a single transfer lens can be optimally positioned for operation in standard mode, it cannot be optimally positioned when the existing microscope system is operating in Lorentz mode. Therefore, in today's microscope systems, a much lower principal hexapole excitation must be selected. This leads to a suboptimal situation where the corrector is affected by C5. C The contribution of thermomagnetic field noise is not optimally reduced. Moreover, even under this reduced principal hexapole excitation state, suboptimal C5 combined aberrations still exist in current microscope systems. Due to these issues, the Lorentz STEM resolution achievable with current single transfer lens configurations is limited.

[0022] However, the exemplary charged particle microscope system (one or more) 100 according to this disclosure addresses these issues by incorporating an additional transfer lens between the corrector and the first transfer lens 124 (i.e., the second transfer lens 126). By replacing a single lens in an existing system with two well-positioned and / or optically ideally configured transfer lenses, the exemplary charged particle microscope system (one or more) 100 disclosed herein can be optimized in multiple operating modes (i.e., standard mode and Lorentz mode). That is, according to this disclosure, the position and / or optical properties of the first transfer lens 124 and the second transfer lens 126 are optimized such that the performance of the exemplary charged particle microscope system 100 is optimized in both normal operating mode and Lorentz operating mode. For example, the second transfer lens 126 allows tuning of C5, C in Lorentz operating mode. S And defocusing to optimally balance C7 aberrations. In addition to limiting these higher-order geometric aberrations, the second transfer lens 126 may be positioned and / or otherwise optically configured to reduce chromatic aberration and / or thermomagnetic field noise.

[0023] Furthermore, in some embodiments, the first transfer lens 124 and the second transfer lens 126 may also be positioned and / or otherwise optically configured to provide improved performance of the example charged particle microscope system 100 in standard operating mode compared to a single transfer lens configuration. For example, in the standard operating mode of a charged particle microscope system, the accelerating voltage range is quite wide (e.g., 30 to 300 kV). In existing systems with current single transfer lens configurations, designs optimized for high-end accelerating voltages (e.g., 300 kV) are not optimal for low-end accelerating voltages (e.g., 30 kV). However, in the example charged particle microscope system(s) 100 according to this disclosure, the second transfer lens 126 provides additional degrees of freedom that allow the focusing column 114 to be optimized across the entire accelerating voltage range.

[0024] Figure 1 An example charged particle microscopy system (one or more) 100 is also illustrated, which includes a sample holder 128 for holding a sample 102. The example charged particle microscopy system (one or more) 100 is also shown including a detector 130 configured to detect charged particles that have passed through the sample 102 as a charged particle beam 104 is incident on the sample 102. Furthermore, the example charged particle microscopy system (one or more) 100 is illustrated including astigmatism correction and a scanning coil 132 for causing the charged particle beam 104 to scan the surface of the sample 102. For example, by operating the scanning coil 132, the direction of the charged particle beam 104 can be changed so that it hits different locations on the sample 102. The example charged particle microscopy system (one or more) 100 also includes one or more projection lenses 136 located between the sample 102 and the detector 130.

[0025] Figure 1 Example charged particle microscope systems (one or more) 100, optionally including computing devices (one or more) 134, are also shown. Those skilled in the art will understand that... Figure 1 The computing device 134 depicted is merely illustrative and is not intended to limit the scope of this disclosure. Computing systems and devices may include any combination of hardware or software capable of performing the indicated functions, including computers, network devices, internet appliances, PDAs, wireless telephones, controllers, oscilloscopes, amplifiers, etc. The computing device 134 may also be connected to other devices not shown, or alternatively may operate as a standalone system. Furthermore, in some embodiments, the functionality provided by the illustrated components may be combined in fewer components or distributed across additional components. Similarly, in some embodiments, some of the functionality of the illustrated components and / or other additional functionality may not be provided and may be available.

[0026] The computing device 134(one or more) may be a component of the example charged particle microscopy system(one or more) 100, or may be a device separate from the example charged particle microscopy system(one or more) 100, which communicates with the example charged particle microscopy system(one or more) 100 via a network communication interface or a combination thereof. For example, the example charged particle microscopy system(one or more) 100 may include a first computing device 134, which is a component of the example charged particle microscopy system(one or more) 100 and acts as a controller for driving the operation of the example charged particle microscopy system(one or more) 100 (e.g., adjusting the scanning position on the sample 102 by operating the scanning coil 132, etc.). In such embodiments, the example charged particle microscopy system(one or more) 100 may also include a second computing device 134, which is a desktop computer separate from the example charged particle microscopy system(one or more) 100 and is capable of processing data received from the detector 134 to generate images of the sample 102 and / or performing other types of analysis. The computing device 134 can receive user selections via a keyboard, mouse, touchpad, touchscreen, etc.

[0027] Computing device 134 includes one or more processors configured to execute instructions, applications, or programs stored in one or more processor-accessible memories. In some instances, the one or more processors may include hardware processors, including but not limited to hardware central processing units (CPUs), graphics processing units (GPUs), etc. Although in many cases these technologies are described herein as being executed by one or more processors, in some cases these technologies may be implemented by one or more hardware logic components, such as field-programmable gate arrays (FPGAs), complex programmable logic devices (CPLDs), application-specific integrated circuits (ASICs), system-on-a-chip (SoCs), or combinations thereof.

[0028] One or more processor-accessible memories are examples of computer-readable media. Computer-readable media can include two types: computer storage media and communication media. Computer storage media can include volatile and non-volatile, removable and non-removable media implemented in any method or technology for storing information, such as computer-readable instructions, data structures, program modules, or other data. Computer storage media include, but are not limited to, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EEPROM), flash memory or other storage technologies, optical disc read-only memory (CD-ROM), digital universal disk (DVD) or other optical storage devices, magnetic tape cassettes, magnetic tape, disk storage devices or other magnetic storage devices, or any other non-transfer medium that can be used to store desired information and is accessible by a computing device. Generally, computer storage media can include computer-executable instructions that, when executed by one or more processing units, cause the various functions and / or operations described herein to be performed. Conversely, communication media embody computer-readable instructions, data structures, program modules, or other data in modulated data signals (such as carrier waves) or other transmission mechanisms. As defined herein, computer storage media does not include communication media.

[0029] Those skilled in the art will also understand that, for memory management and data integrity purposes, items or portions thereof may be transferred between memory and other storage devices. Alternatively, in other embodiments, some or all of the software components may be executed in memory on another device and communicate with computing device 134. Some or all of the system components or data structures may also be stored (e.g., as instructions or structured data) on a non-transitory computer-accessible medium or portable article for retrieval by a suitable drive, various examples of which are described above. In some embodiments, instructions stored on a computer-accessible medium separate from computing device 134 may be transmitted to computing device 134 via a transmission medium or signal (such as an electronic, electromagnetic, or digital signal transmitted via a communication medium such as a wireless link). Various embodiments may also include receiving, transmitting, or storing instructions and / or data implemented according to the foregoing description on a computer-accessible medium.

[0030] Figure 2 This is a set of diagrams 200, which illustrate the optical behavior of a corrector-transfer optics in a charged particle system with a corrector and one or more lenses. Specifically, diagrams 210, 220, and 230 illustrate the optical behavior that takes into account the aberrations present in such charged particle systems.

[0031] Figure 210 illustrates the general scheme for correcting a STEM, which clarifies the effective focal length used in equation (1) below. The meaning of ). Each of the diagrams 210, 220, and 230 illustrates the charged particle beam 104 in xz Axial rays in the plane, where z The axis corresponds to the emission axis 110 of the example charged particle microscope system (one or more) 100.

[0032] When calculating the performance of an example charged particle microscope system (one or more) 100, we can assume that the axial ray 202 of the charged particle beam 104 is parallel to the emission axis 110 as it exits the corrector 116, and that the corrector exit plane 204 corresponds to the plane where positional aberrations are zero or minimal. For example, in the case of a hexapole corrector 116, the exit plane is a virtual plane at the center of the last master hexapole. Effective focal length ( It can be defined as:

[0033] (1)

[0034] in = / ( (always less than 1 in sample plane 206), and Let x be the x-coordinate in the corrector exit plane 204. Since there is no net acceleration or deceleration between the corrector 116 and the sample 102, the transfer of the first-order ray from the corrector exit plane 204 to the sample plane 206 is governed by the following transfer matrix with determinant = 1:

[0035] (2)

[0036] Figure 220 illustrates an optical scheme for correcting a STEM, featuring an objective lens 120 but without a transfer lens. Using a simplified thin lens model, the effect of the lens is given by equation (3), where C is the focal length. s C1 and C5 are the 3rd and 5th order spherical aberration coefficients, respectively.

[0037] (3)

[0038] In equation (3), the subscript "in" refers to the incident electrons (one or more), and the subscript "out" refers to the emitted electrons (one or more), both of which are in the plane of the thin lens. At the starting point of the corrector's exit plane 204, when the corrector intensity (K3) is greater than 0, then:

[0039] (4)

[0040] The drift space between the corrector and objective lens 120 is expressed by the following formula:

[0041] (5)

[0042] Equation (5) shows that this drift space between the corrector and objective lens 120 results in a third-order positional aberration, which in turn produces a fifth-order combined aberration via the following relationship:

[0043] (6)

[0044] This results in the following: the movement of objective lens 120 and its subsequent drift to sample plane 206:

[0045] + (7)

[0046] And therefore:

[0047] (8)

[0048] From the angle In other words, this becomes:

[0049] (9)

[0050] Therefore, if the correction strength follows = Then implement C S aberration correction, which leads to The total fifth-order aberration coefficients are:

[0051] (10)

[0052] Figure 230 illustrates the optical scheme for a corrected STEM with objective lens 120 and transfer lens 124. Typically, the aberrations of the transfer lens 124 and objective lens 120 are dominated by the objective lens contribution. In the simplest case, where the aberrations of the transfer lens are negligible and the C5 of objective lens 120 is zero, the total C5 of the system is zero if the corrector exit plane is imaged onto the objective lens, as depicted in Figure 230. The transfer optics then simultaneously ensure that off-axis isotropic coma is small, which relates to the imaging corrector in TEM mode. In practice, there is a small difference between zero isotropic coma and optimal C5 in the transfer lens setting, so it must be determined which is more important. This difference (and the resulting dilemma) can be further reduced by allowing non-parallel illumination of the sample. In Lorentz TEM mode, off-axis coma is typically small enough for C5 to be zero or for the optimal balance C7.

[0053] In this type of optical configuration, there is no positional aberration in the objective plane 208, and therefore no combination C5. However, for different excitations of the transfer lens, we again have positional aberrations in the lens:

[0054] (11)

[0055] Where the distance It can have any sign, and therefore the corresponding combination C5 can also have any sign. For example, in the case where the system in Figure 230 includes a weaker transfer lens 124, the weaker transfer lens 124 can produce a negative combination C5, which can correct the positive C5 of the objective lens 120 (within certain limits).

[0056] Again, assuming the transfer lens is 124 (with a focal length) f t This allows the corrector's exit plane 204 to be precisely imaged onto the objective lens 120. This means... f t = ,and:

[0057] (12)

[0058] In fact, for a given objective lens of 120, b and L It is more or less given, and the optical designer has a single degree of freedom to optimize the distance. a This allows for optimization of the optical configuration for a single objective 120. However, if objective 120 is closed and another lens acts as a functional objective (such as when the instance charged particle microscope system (one or more) 100 is operating in Lorentz operating mode), this configuration will no longer be optimized.

[0059] Therefore, in order for the optical system to use the maximum corrector strength of 116 for both standard operating mode and Lorentz mode. ,but:

[0060] (13)

[0061] Subscript L This refers to the Lorenz mode. Furthermore, using typical ratios, the optimal distance between the Lorenz operating mode and the standard operating mode can be determined based on the following relationship. a The ratio between:

[0062] (14)

[0063] in The value is between 0.4 and 0.6. Therefore, the optimal distance for the transfer lens 124 is [value missing] in Lorentz operation mode. This is significantly smaller than the optimal distance in standard operating mode. In some embodiments, the distance used for the transfer lens 124 is... Less than in equation (14) In such embodiments, both the first and second transfer lenses are excited in Lorentz mode. For example, in a preferred embodiment, It can be selected such that there is a crossover point of the charged particle beam 104 in the first transfer lens 124, thereby achieving defocusing, C S There is decoupling between the tuning of C5 and C5.

[0064] For Cs correctors with non-parallel beams (e.g., on the side facing the sample), similar calculations can be performed. For example, consider a STEM Cs corrector with a beam crossover point in the exit plane, where there is no third-order tilt aberration—only the third-order positional aberration corresponding to negative Cs. This ultimately leads to:

[0065]

[0066] in It is typically a value between 0.4 and 0.6. Therefore, in this case, the optimal distance for the transfer lens 124 is [value missing] in Lorentz operating mode. It is significantly less than the optimal distance in standard operating mode.

[0067] As mentioned above... Figure 1 As discussed in the comments, the exemplary charged particle microscope system(s) 100 disclosed herein overcomes this difference in optimal distance by incorporating an additional transfer lens 126 between the corrector 116 and the transfer lens 124. Including this transfer lens 126 provides optical designers with additional degrees of freedom for optimizing the system, which in turn allows them to optimize system performance (i.e., reduce and / or correct aberrations) in both standard and Lorentz operating modes. Such optimization is not possible in existing single transfer lens configurations.

[0068] Figure 3 An example charged particle microscope system (one or more) 100 is shown, which is a TEM system 300 capable of operating in standard operating mode and Lorentz operating mode.

[0069] The TEM system 300 is configured to irradiate the sample 102 with a beam 104 of charged particles emitted by a charged particle source 108. For example... Figure 3 As shown, the path of the charged particle beam 104 changes according to the operating mode of the example charged particle microscope system (one or more) 100. For example, Figure 3The diagram shows the charged particle beam 104 following beam path 304(a) when the TEM system 300 operates in standard operating mode, and following beam path 304(b) when the TEM system 300 operates in Lorentz operating mode. The accelerator lens 112 accelerates / decelerates, focuses, and / or directs the charged particle beam 104 toward the sample 102. In some embodiments, the TEM system 300 includes a focusing column 306 that guides the charged particle beam 104 to incident on the sample 102.

[0070] Figure 3 The diagram also illustrates a TEM system 300, which includes a corrector 116 positioned in the path of axial electrons 105 scattered by sample 102. The corrector 116 is an optical component for correcting axial (and in some cases off-axis) aberrations of the charged particle beam 104. Figure 3 In the illustration, the TEM system 300 is also shown to include an arrangement of multiple lenses 118, including an objective lens 120, a Lorentz lens 122, a first transfer lens 124, and a second transfer lens 126. In some embodiments, the objective lens 120 is closed when the example charged particle microscope system 100 is operating in Lorentz mode. In such embodiments, the Lorentz lens 122 functions as an objective lens. The Lorentz lens 122 is an optical lens that causes the divergent portion of the charged particle beam 104 from the objective lens 120 to become a converging beam and / or a more convergent beam. For example, Figure 3 The illustration shows a Lorentz lens 122, which causes a portion of the charged particle beam 104 to become a more convergent beam when the TEM system 300 is operating in standard operating mode, and a convergent beam when the TEM system 300 is operating in Lorentz mode.

[0071] like Figure 3 As shown, the path of the axial electron 105 changes according to the operating mode of the example charged particle microscope system (one or more) 300. For example, Figure 3 It is shown that when the example charged particle microscope system (one or more) 300 is operating in standard operating mode, the axial electrons 105 follow path 105(a), while when the example charged particle microscope system (one or more) 300 is operating in Lorentz operating mode, the axial electrons follow path 105(b).

[0072] Figure 3 The illustration also shows an arrangement of multiple lenses 118, including a first transfer lens 124 and a second transfer lens 126. Traditionally, similar microscope systems contain only a single transfer lens, which is positioned and / or otherwise configured with its optical properties to optimize the performance of the microscope system during a single operating mode. Furthermore, such single transfer lens arrangements are not suitable for Lorentz microscopes with non-immersion objectives.

[0073] Figure 3 Also illustrated is a TEM system 300 including a camera 302 configured to receive the charged particle beam 104 after it leaves the corrector 116. The camera 302 is configured to generate an image of the sample 102 and / or determine compositional information of the sample based on a portion of the received charged particle beam 104. Figure 3 Example charged particle microscope system (one or more) 100, which optionally includes computing devices (one or more) 134, is also shown.

[0074] Figure 4 Example charged particle microscopy systems (one or more) 100 are shown, which are SEM systems 400 capable of operating in standard and Lorentz operating modes. Figure 4 As shown, the path of the charged particle beam 104 changes according to the operating mode of the example charged particle microscope system (one or more) 400. For example, Figure 4 It is shown that when the example charged particle microscope system (one or more) 100 is operating in standard operating mode, the charged particle beam 104 follows beam path 104(a), while when the example charged particle microscope system (one or more) 100 is operating in Lorentz operating mode, the charged particle beam follows beam path 104(b).

[0075] Example charged particle microscopy system (one or more) 400 includes a charged particle source 108 that emits a charged particle beam 104 along an emission axis 110 toward an accelerator lens 112. The accelerator lens 112 accelerates / decelerates, focuses, and / or directs the charged particle beam 104 toward a focusing column 114. The focusing column 114 focuses the charged particle beam 104 such that it is incident on a sample 102. Additionally, the focusing column 114 corrects for and / or tunes aberrations (e.g., geometric aberrations, chromatic aberrations, etc.) in the charged particle beam 104. Figure 4 In the diagram, the focusing column 114 is illustrated as an arrangement including a corrector 116 and a plurality of lenses 118. The corrector 116 is an optical component for correcting axial aberrations of the charged particle beam 104.

[0076] exist Figure 4 In the illustration, the focusing column 114 is also shown as an arrangement including a plurality of lenses 118, including an objective lens 120, a Lorentz lens 122, a first transfer lens 124, and a second transfer lens 126. In some embodiments, when the example charged particle microscope system 400 is operating in Lorentz mode, the objective lens 120 is closed. In such embodiments, the Lorentz lens 122 functions as an objective lens and focuses the charged particle beam 104 onto the sample. For example, Figure 4The illustration shows a Lorentz lens 122 that causes the divergent portion of the charged particle beam 104 to (a) become a smaller divergent beam when the example charged particle microscope system 400 is operating in standard operating mode, and (b) become a converging beam when the example charged particle microscope system 400 is operating in Lorentz mode.

[0077] Figure 4 The illustration also shows an arrangement of a plurality of lenses 118, including a first transfer lens 124 and a second transfer lens 126. According to this disclosure, the position and / or optical properties of the first transfer lens 124 and the second transfer lens 126 are optimized such that the performance of the example charged particle microscope system 400 is optimized in both normal operating mode and Lorentz operating mode. Furthermore, in some embodiments, the first transfer lens 124 and the second transfer lens 126 may also be positioned and / or otherwise optically configured to provide improved performance of the example charged particle microscope system 400 in standard operating mode compared to a single transfer lens configuration.

[0078] Figure 4 Example charged particle microscopy system(s) 400 is also illustrated, which includes a sample holder 128 for holding a sample 102. Example charged particle microscopy system(s) 400 is also shown including a detector 130 configured to detect charged particles emitted and / or reflected by the sample 102 as a charged particle beam 104 is incident on the sample 102. Furthermore, example charged particle microscopy system(s) 100 is illustrated including astigmatism correction and a scanning coil 132 for causing the charged particle beam 104 to scan the surface of the sample 102. Figure 4 Example charged particle microscope system (one or more) 400, which optionally includes computing devices (one or more) 134, is also shown.

[0079] Figure 5 This is a flowchart illustrating an illustrative process, shown as a collection of boxes in a logic flowchart, representing a series of operations that can be implemented in hardware, software, or a combination thereof. In the context of software, these boxes represent computer-executable instructions stored on one or more computer-readable storage media that, when executed by one or more processors, perform the operations. Typically, computer-executable instructions include routines, programs, objects, components, data structures, etc., that perform a specific function or implement a specific abstract data type. The order in which the operations are described is not intended to be construed as limiting, and any number of the described boxes can be combined in any order and / or in parallel to implement these processes.

[0080] Figure 5A sampling process 500 with optimized performance is described for examining, depositing, grinding, and / or extracting sample components using a charged particle microscopy system in multiple operating modes. Process 500 may be implemented in any of the example charged particle microscopy systems (one or more) 100, 300, and 400 and / or via the aforementioned computing device (one or more) 134, or in other environments and computing devices.

[0081] At 502, an operating mode for the charged particle system is selected. For example, the charged particle system may receive input to operate in a standard operating mode or a Lorentz operating mode. The standard operating mode corresponds to the mode of irradiating a sample with a charged particle beam for the purpose of examining, depositing, grinding, and / or extracting sample components. The Lorentz operating mode corresponds to an imaging mode in which magnetic contrast is generated based on the deflection experienced by charged particles passing through a magnetically inductive region within the sample.

[0082] If the Lorentz operating mode is selected at 502, the process continues in step 404, and the objective lens is optionally closed. In embodiments where the objective lens is closed, the Lorentz lens then functions as a functional objective lens.

[0083] In step 506, a charged particle beam is emitted from the charged particle source. Specifically, the charged particle beam is emitted from the charged particle source towards the sample along the emission axis. The charged particle source may include a thermionic source, a Schottky emission source, a field emission source, a liquid metal ion source, a plasma ion source, etc. The emission axis is an axis extending from the charged particle source along the length of the charged particle system and passing through the central axis of the sample.

[0084] At 508, the charged particle beam is focused onto the sample. In some embodiments, the charged particle beam may pass through a focusing column that guides it onto the sample. In some embodiments, the focusing column may include a corrector to correct axial aberrations of the charged particle beam (e.g., a hexapole corrector, which may be a Rose (-type) or S-CORR corrector, or a Crewe (-type) hexapole corrector, or a tetrapole-octapole corrector, or any other type of corrector). Alternatively, in the case where the charged particle system is a transmission microscope, the corrector may be located downstream of the beam path of the sample.

[0085] In 510, the first and second transfer lenses are used to tune aberrations. Specifically, when the charged particle system is in Lorentz operation mode, the first and second transfer lenses are used to tune C5 and C6. S And defocus, to optimally balance C7 aberrations. For example, a corrector in a charged particle system can be used to reduce the negative C7 aberration generated by the corrector. S With the positive C generated by the objective lens SMatching is used to tune one or more axial (and in some cases off-axis) aberrations. In such cases, the first and second transfer lenses can tune any contribution of the corrector and Lorentz lens to C5 to zero. In addition to limiting these higher-order geometric aberrations, the second transfer lens may be positioned and / or otherwise optically configured to reduce chromatic aberration and / or thermomagnetic field noise. In addition to limiting these higher-order geometric aberrations, in some embodiments, the second transfer lens may be positioned and / or otherwise optically configured to allow the main hexapod to be set at a higher excitation level (e.g., maximum excitation), thereby reducing chromatic aberration and / or thermomagnetic field noise. The position and / or optical configuration of the first and second transfer lenses optimizes the performance of the charged particle system in both standard and Lorentz operating modes.

[0086] In step 512, an image is generated and / or compositional information about the sample is determined. For example, a camera or other type of detector may be used to receive a portion of a beam of charged particles transmitted through the sample and / or charged particles reflected / emitted by the sample, and a computing device associated with the charged particle system may generate an image based on data from the camera and / or sensor.

[0087] At step 514, the charged particle system receives input to change its operating mode. If the charged particle system is operating in standard operating mode, the process continues at step 504, and the charged particle system operates in Lorentz operating mode. Alternatively, if the charged particle system is operating in Lorentz operating mode, the process continues at step 516, and the charged particle system operates in standard operating mode. At step 516, the objective lens is optionally opened.

[0088] In step 518, a charged particle beam is emitted from the charged particle source. Specifically, the charged particle beam is emitted from the charged particle source along the emission axis toward the sample.

[0089] At 520, the charged particle beam is focused onto the sample. In some embodiments, the charged particle beam may pass through a focusing column that guides it onto the sample. In some embodiments, the focusing column may include a corrector to correct axial aberrations of the charged particle beam. Alternatively, in the case where the charged particle system is a transmission microscope, the corrector may be located downstream of the beam path of the sample.

[0090] At 522, this pair of transfer lenses is optionally used to tune the performance of the charged particle system. In some embodiments, the first and second transfer lenses may be positioned and / or otherwise optically configured to provide improved performance of the charged particle system. For example, in the standard operating mode of a charged particle microscope system, the accelerating voltage range is quite wide (e.g., 30 to 300 kV). In existing systems with current single transfer lens configurations, if the design is optimized for high-end accelerating voltages (e.g., 300 kV), the design is not optimal for low-end accelerating voltages (e.g., 30 kV). However, in the example charged particle system according to this disclosure, the second transfer lens provides additional degrees of freedom that allow the charged particle system to be optimized across the entire accelerating voltage range. The process then continues to step 512, where an image is generated and / or compositional information about the sample is determined.

[0091] Figure 6 and 7 The figures illustrate the optical performance of a system with a single transfer lens arrangement and a system with a multiple transfer lens arrangement, respectively. Figure 6 The diagram illustrates the optical performance of a system with a single transfer lens arrangement operating in Lorentz operation mode, wherein the position of this transfer lens is optimal for normal operation mode. Figure 6 The beam paths of the axial ray 602 and the off-axis ray 604 of the charged particle beam 102 are shown, both having an intersection point at the center of the main hexapole, wherein the corrector 116 is an S-CORR operating at a specific accelerating voltage. Figure 7 The diagram illustrates the optical performance of a system with a multi-transfer lens arrangement operating in Lorentz operation mode. Figure 7 The beam paths of the axial rays 702 and the off-axis rays 704 of the charged particle beam 102 are shown, with the corrector 116 operating at a specific accelerating voltage. Figure 7 In the process, the main hexapole of the corrector 116 is excited, requiring a very small central hexapole excitation to produce A5 = 0. The first transfer lens 124 and the second transfer lens 126 are optimally positioned so that C5, C S Defocus was tuned to optimal balance C7. Additionally, 3x aberrations A2 and D4 were tuned to optimal balance D6.

[0092] Examples of the inventive subject matter according to this disclosure are described in the following paragraphs.

[0093] A1. A charged particle microscope configured to operate in a standard operating mode when in a first configuration and in a Lorentz operating mode when in a second configuration, the charged particle microscope comprising:

[0094] A charged particle source, configured to emit a beam of charged particles toward a sample;

[0095] A sample holder, configured to hold a sample;

[0096] Corrector, which is used to correct axial aberrations;

[0097] A Lorentz lens, located between the corrector and the sample holder;

[0098] The objective lens, positioned between the Lorentz lens and the sample holder;

[0099] The first transfer lens is located between the corrector and the Lorentz lens;

[0100] A second transfer lens is located between the corrector and the first transfer lens; and

[0101] The charged particle microscope is configured to switch between a first configuration in which it operates in standard operating mode and a second configuration in which it operates in Lorentz mode.

[0102] A1.1. According to the charged particle microscope in paragraph A1, the second transfer lens is configured as follows:

[0103] When the charged particle microscope is operated in Lorentz mode, the beam intersection point of the axial rays of the charged particle beam in the first transfer lens is located at or near the center of the first transfer lens; and

[0104] When the charged particle microscope is operating in standard operating mode, the auxiliary first transfer lens images the corrector exit plane onto a plane close to the objective lens to minimize combined aberration C5.

[0105] A1.1.1. According to the charged particle microscope in paragraph A1.1, the first and second transfer lenses are positioned and / or otherwise configured to tune C5 and C when the charged particle system is in Lorentz operating mode. S And defocusing, to optimally balance C7 aberrations in charged particle microscopy.

[0106] A1.1.2. The charged particle microscope according to paragraph A1.1, wherein the second transfer lens is positioned and / or otherwise configured such that when the charged particle microscope is operated in Lorentz operating mode, the effective focal length is optimal for the desired corrector strength.

[0107] A1.1.2.1. According to the charged particle microscope in paragraph A1.1.2, where the total C corresponding to the corrector intensity S When the focal length is zero, the effective focal length is optimal.

[0108] A1.1.2.2. Charged particle microscope according to any of paragraphs A1.1.2-A1.1.2.1, wherein the second transfer lens is positioned and / or otherwise configured such that the effective focal length is optimal at the large and / or maximum corrector strength.

[0109] A1.1.2. A charged particle microscope according to any of paragraphs A1.1-A1.1.1.1, wherein when the charged particle microscope is operating in standard operating mode, the second lens is configured to assist the first transfer lens in imaging the exit plane of the corrector onto a plane at or near the objective lens.

[0110] A1.1.3. Charged particle microscope according to any of paragraphs A1.1-A1.1.2, wherein when the charged particle microscope is operating in standard operating mode, the second transfer lens is positioned and / or otherwise configured such that the effective focal length is optimal for the multiple accelerating voltage ranges of the charged particle microscope.

[0111] A2. A charged particle microscope according to any of paragraphs A1-A1.1.3, wherein the second transfer lens is configured such that when the charged particle microscope is operated in Lorentz operation mode, the diameter of the charged particle beam in the Lorentz lens is larger than the diameter when the charged particle microscope is operated in standard operation mode.

[0112] A3. Based on any paragraph of A1-A2 regarding charged particle microscopy, where, when the charged particle microscope is operating in standard operating mode, the second transfer lens assists the first transfer lens in imaging to reduce and / or achieve zero-focus, C s And C5.

[0113] A3.1. According to the charged particle microscope in paragraph A3, the second transfer lens of the auxiliary transfer lens includes the second transfer lens that assists the first transfer lens in imaging the exit plane of the corrector onto a plane close to the objective lens.

[0114] A4. Charged particle microscope according to any of paragraphs A1-A3.1, wherein the second transfer lens is positioned such that the performance of the charged particle microscope is optimized in both Lorentz operation mode and standard operation mode.

[0115] A5. According to any of paragraphs A1-A4, a charged particle microscope, wherein when the charged particle microscope is operated in Lorentz operation mode, a second transfer lens focuses the charged particle beam to reduce and / or tune one or more spherical aberration coefficients.

[0116] A5.1. The charged particle microscope according to paragraph A5, wherein a second transfer lens that focuses a charged particle beam to reduce and / or tune one or more spherical aberration coefficients, further comprises one or more of a corrector, a first transfer lens, a Lorentz lens, and an objective lens that works with the second transfer lens to reduce and / or tune one or more spherical aberration coefficients.

[0117] A5.2. Based on any paragraph A5-A5.1 of the charged particle microscope, where reducing and / or tuning one or more spherical aberration coefficients includes optimally tuning defocus, C s And one or more of C5.

[0118] A5.3. Charged particle microscopy according to any paragraph A5-A5.2, wherein the charged particle microscopy is operated in Lorentz operation mode, and the second transfer lens focuses the charged particle beam to cause a reduction and / or tuning of the fifth-order spherical aberration coefficient.

[0119] A5.4. Charged particle microscopy according to any of paragraphs A5-A5.3, wherein reducing and / or tuning one or more spherical aberration coefficients involves tuning the position of off-axis rays in the Lorentz lens to compensate for one or more spherical aberration coefficients.

[0120] A5.4.1. According to paragraph A5.4 of the charged particle microscope, reducing and / or tuning one or more spherical aberration coefficients involves causing the position of off-axis rays in the Lorentz lens to pass through or near the center of the Lorentz lens.

[0121] A5.4. Charged particle microscopy based on any of paragraphs A5-A5.3.2, wherein the objective lens is closed in Lorentz mode and the Lorentz lens acts as the functional objective lens.

[0122] A6. Based on any paragraph of A1-A5.4, the charged particle microscope has the following correctors: hexapolar corrector, Rose corrector, Rose-type corrector, S-CORR corrector, Crewe corrector, Crewe-type corrector, hexapolar corrector, and quadrupole-octupole corrector.

[0123] A7. Based on any of paragraphs A1-A6, the charged particle microscope contains either a Schottky FEG or a cold FEG.

[0124] A8. Based on any paragraph from A1-A7, the charged particle microscope also includes a monochromator and a simple C... c One or two of the correctors.

[0125] A8.1. Charged particle microscope according to paragraph A8, wherein the charged particle microscope contains a split Wien filter with a nanoscale slit in the midplane, which acts as both a monochromator and a simple Cc corrector.

[0126] A9. Based on any paragraph A1-A8.1, the charged particle microscope is a transmission electron microscope.

[0127] A9.1. Charged particle microscopy according to paragraph A9, wherein the sample holder is located between the charged particle source and the corrector.

[0128] A10. Based on any paragraph A1-A8.1, the charged particle microscope is a scanning electron microscope.

[0129] A10.1. Charged particle microscopy according to paragraph A10, wherein the corrector is located between the charged particle source and the sample holder.

[0130] B1. A method for operating a charged particle microscope (configured to operate in a standard operating mode when in a first configuration and in a Lorentz operating mode when in a second configuration), the method comprising:

[0131] This causes a beam of charged particles to be emitted from the charged particle source toward the sample;

[0132] Corrected via a corrector, used to correct axial aberrations;

[0133] When the charged particle microscope is operated in Lorentz mode, a second transfer lens is used such that the beam intersection point of the axial rays of the charged particle beam in the first transfer lens is located at or near the center of the first transfer lens; and

[0134] When the charged particle microscope is operating in standard operating mode, a second transfer lens is used to assist the first transfer lens in imaging the corrector exit plane onto a plane close to the objective lens, in order to minimize combined aberration C5.

[0135] B1.1. According to the method in paragraph B1, wherein: when the charged particle microscope is operated in Lorentz operating mode, focusing the charged particle beam includes using a second transfer lens such that the intersection point of the axial beams of the charged particle beam in the first transfer lens is at or near the center of the first transfer lens; and when the charged particle microscope is operated in standard operating mode, using the second transfer lens to assist the first transfer lens includes using the second transfer lens to assist the first transfer lens in imaging the corrector exit plane onto a plane close to the objective lens.

[0136] B2. According to the method in any of paragraphs B1-B1.1, it also includes switching between Lorentz operating mode and standard operating mode.

[0137] B2.1. According to the method in paragraph B2, the charged particle microscope includes a Lorentz lens and an objective lens, and wherein when the charged particle microscope is operated in Lorentz operating mode, the objective lens is closed, and the Lorentz lens acts as a functional objective lens.

[0138] B2.1.1. According to the method in paragraph B2.1, wherein when the charged particle microscope is operated in Lorentz operating mode, the second transfer lens is configured such that the position of the axial rays of the charged particle beam in the Lorentz lens is further away from the center of the Lorentz lens than when the charged particle microscope is operated in standard operating mode.

[0139] B2.1.2. The method according to any of paragraphs B2.1-B2.1.1, wherein the charged particle beam is focused by the second transfer lens such that the position of the charged particle beam in the first transfer lens is reduced and / or the fifth-order spherical aberration coefficient is tuned such that the position of the off-axis ray in the Lorentz lens does not pass through the center of the Lorentz lens.

[0140] B3. The method described in any of paragraphs B1-B2.1.2, wherein the second transfer lens is positioned such that the performance of the charged particle microscope is optimized in both Lorentz operation mode and standard operation mode.

[0141] C1. Use the charged particle microscope in any of paragraphs A1-A10 to perform the method in any of paragraphs B1-B3.

[0142] D1. A computer-readable medium storing non-transitory computer-readable instructions, which, when executed by one or more processors, cause a charged particle microscope in any of paragraphs A1-A10 to perform the method in any of paragraphs B1-B3.

Claims

1. A charged particle microscope configured to operate in a normal operating mode when in a first configuration and in a Lorentz operating mode when in a second configuration, the charged particle microscope comprising: A charged particle source configured to emit a beam of charged particles toward a sample; A sample holder configured to hold the sample; Corrector, the corrector being used to correct axial aberrations; A Lorentz lens, wherein the Lorentz lens is located between the corrector and the sample holder; Objective lens, located between the Lorentz lens and the sample holder; and The charged particle microscope is configured such that it further includes: A first transfer lens is located between the corrector and the Lorentz lens; A second transfer lens is located between the corrector and the first transfer lens; and The charged particle microscope is configured to switch between a first configuration for operation in standard operating mode and a second configuration for operation in Lorentz mode, wherein when the charged particle microscope is operating in Lorentz operating mode, the second transfer lens is configured such that the position of the axial rays of the charged particle beam in the Lorentz lens is further away from the center of the Lorentz lens than when the charged particle microscope is operating in standard operating mode.

2. The charged particle microscope of claim 1, wherein the second transfer lens is configured such that, when the charged particle microscope is operated in the Lorentz operating mode, the intersection point of the axial beams of the charged particle beam in the first transfer lens is located at or near the center of the first transfer lens.

3. The charged particle microscope according to any one of claims 1 and 2, wherein the second transfer lens is configured to assist the first transfer lens in imaging the exit plane of the corrector to minimize combined aberration C5 when the charged particle microscope is operating in the standard operating mode.

4. The charged particle microscope according to claim 3, wherein the second transfer lens assisting the first transfer lens comprises the second transfer lens assisting the first transfer lens in imaging the corrector exit plane onto a plane close to the objective lens.

5. The charged particle microscope according to any one of claims 1 and 4, wherein the first transfer lens and the second transfer lens are positioned and / or configured to tune C5, C when the charged particle microscope is in Lorentz operating mode. S And defocusing, to optimally balance the C7 aberration within the charged particle microscope.

6. The charged particle microscope according to any one of claims 1, 2 and 4, wherein the second transfer lens is positioned and / or configured such that the effective focal length is optimal for the desired corrector strength when the charged particle microscope is operated in the Lorentz operating mode.

7. The charged particle microscope according to any one of claims 1, 2 and 4, wherein when the charged particle microscope is operated in the standard operating mode, the second transfer lens is positioned and / or configured such that the effective focal length is optimal for the multiple accelerating voltage ranges of the charged particle microscope.

8. The charged particle microscope of claim 1, wherein the second transfer lens is configured such that when the charged particle microscope is operated in the Lorentz operating mode, the diameter of the charged particle beam in the Lorentz lens is larger than the diameter of the charged particle beam when the charged particle microscope is operated in the standard operating mode.

9. The charged particle microscope according to claim 1, wherein the second transfer lens (126) is positioned such that the performance of the charged particle microscope is optimized in both the Lorentz operating mode and the standard operating mode.

10. The charged particle microscope according to any one of claims 1, 8 and 9, wherein when the charged particle microscope is operated in the Lorentz operating mode, the second transfer lens focuses the charged particle beam to reduce and / or tune one or more spherical aberration coefficients.

11. The charged particle microscope of claim 10, wherein the charged particle microscope operates in the Lorentz operating mode, and the second transfer lens focuses the charged particle beam to cause a reduction and / or tuning of the fifth-order spherical aberration coefficient.

12. The charged particle microscope of claim 10, wherein the objective lens is closed in the Lorentz mode, and the Lorentz lens acts as a functional objective lens.

13. The charged particle microscope according to any one of claims 1, 2, 4, 8 and 9, wherein the charged particle microscope is a transmission electron microscope, and the sample holder is located between the charged particle source and the second transfer lens.

14. The charged particle microscope according to any one of claims 1, 2, 4, 8 and 9, wherein the charged particle microscope is a scanning electron microscope, and the second transfer lens is located between the charged particle source and the sample holder.

15. Use of a charged particle microscope according to any one of claims 1 to 4 and 8 to 11 for examining samples in at least one of a standard operating mode and a Lorentz operating mode.

Images