Modular optical inspection platform assembly

Abstract

The invention relates to an optical detection platform assembly configured to be located within an optical chamber of a charged particle system. The optical detection platform assembly includes a housing defining a plurality of openings and a channel defining a beam axis of a charged particle beam, and a plurality of optical brackets. Each of the plurality of optical supports includes a base portion, and one or more arms extending from the base portion. The one or more arms of each optical bracket are removably mounted on the housing and located within a first of the plurality of openings, the base portion of each optical bracket is configured to receive a multipole element, and the base portion of each optical bracket is located within the channel such that each multipole element is aligned with each other along the beam axis. The invention also relates to a charged particle system and to an optical mount.

Description

Technical Field

[0001] This invention relates to an optical inspection platform assembly. It also relates to a charged particle system and an optical support. Background Technology

[0002] Charged particle systems have a variety of applications, including the fabrication, repair, and inspection of microdevices such as integrated circuits, magnetic recording heads, and photolithographic masks. One type of charged particle system is the electron microscope. As an imaging tool, the electron microscope works by focusing a sufficiently small electron beam generated by an electron emitter onto a specific location on the sample. By detecting the signal electrons (or photons) emitted from that location, a high-resolution image of the sample is generated. Summary of the Invention

[0003] In one aspect, this disclosure provides an optical detection platform assembly configured to be located within an optical cavity of a charged particle system. The optical detection platform assembly includes a housing defining a plurality of openings and a channel defining a charged particle beam axis, as well as a plurality of optical supports. Each of the plurality of optical supports includes a base portion and one or more arms extending from the base portion. The one or more arms of each optical support are detachably mounted to the housing and located within a first opening of the plurality of openings. The base portion of each optical support is configured to accommodate a multipole element, and the base portion of each optical support is located within the channel such that each multipole element is aligned with each other along the beam axis.

[0004] Specific implementations may include one or more of the following features. The one or more arms may include multiple arms. A first arm of the multiple arms may be detachably mounted within a first opening, and a second arm of the multiple arms may be detachably mounted within a second opening of the multiple openings. The cross-sectional area of ​​the second opening may be larger than the cross-sectional area of ​​the first opening. A third arm of the multiple arms may be detachably mounted within the second opening. Each of the multiple optical supports may include a sphere received within one or more arms. One or more arms may include a spring mechanism configured to engage with the sphere. The spring mechanism may be a cantilever spring or a leaf spring. A housing may define a recess configured to receive the sphere. The multipole element may include an electrostatic multipole element. The electrostatic multipole element may include one or more electrostatic single lenses.

[0005] On one hand, this disclosure provides a charged particle system, comprising: a charged particle source configured to emit a charged particle beam along a beam axis, and an optical chamber in fluid communication with the charged particle source. The optical chamber includes an optical detection platform assembly having a housing defining a plurality of openings and a channel aligned with the beam axis, and an optical support including a base portion and one or more arms extending from the base portion. A first arm of the one or more arms is coupled to the housing within a first opening of the plurality of openings, and the base portion is located within the channel. The optical chamber also includes a multipole element housed in the base portion and aligned with the beam axis.

[0006] Specific implementations may include one or more of the following features. The one or more arms may include multiple arms, with a first arm detachably mounted within a first opening, and a second arm detachably mounted within a second opening. The arms may be approximately equiangularly distributed around a base portion. An optical chamber may define a vacuum space configured to be in a vacuum state, within which an optical detection platform assembly may be located. Each of the multiple optical supports may include a sphere received within one or more arms. One or more arms may include a spring mechanism configured to engage with the sphere. A housing may define a recess configured to receive the sphere. The multipole element may include an electrostatic multipole element.

[0007] In one aspect, this disclosure provides an optical support configured in an optical detection platform assembly of a charged particle system. The optical support includes a plurality of spheres, a base portion defining an optical aperture, and a plurality of arms extending from the base portion. Each of the plurality of arms defines an arm aperture and includes a lever mechanism; each of the plurality of spheres is located within the arm aperture of the corresponding arm, and the lever mechanism of each arm is configured to engage with the sphere. The optical support also includes an optical element received within the optical aperture. Attached Figure Description

[0008] The nature and advantages of the various embodiments can be further understood by referring to the following figures. In the figures, similar components or features may have the same reference numerals. Furthermore, various components of the same type may be distinguished by a hyphen following the reference numeral and a second reference numeral to distinguish similar components. If only the first reference numeral is used in the specification, the description applies to any similar component having the same first reference numeral, regardless of the second reference numeral.

[0009] Figure 1 shows a simplified cross-sectional view of an exemplary charged particle system according to an embodiment of the present disclosure.

[0010] Figure 2 shows an isometric view of an exemplary optical inspection platform component according to an embodiment of the present disclosure.

[0011] Figure 3A shows a top isometric view of an exemplary optical bracket and optical element according to an embodiment of the present disclosure.

[0012] Figure 3B shows a bottom isometric view of the exemplary optical bracket and optical element shown in Figure 3A according to an embodiment of the present disclosure.

[0013] Figure 4A shows an isometric view of a first optical support in a housing according to an embodiment of the present disclosure.

[0014] Figure 4B shows a side view of the first optical support in the housing shown in Figure 4A according to an embodiment of the present disclosure.

[0015] Figure 4C shows a cross-sectional view of the first optical support in the housing shown in Figure 4A according to an embodiment of the present disclosure, along the cross section AA.

[0016] Figure 5 shows a cross-sectional view of the first optical support in the housing according to an embodiment of the present disclosure.

[0017] Figure 6 shows a flowchart for generating an image according to an embodiment of the present disclosure.

[0018] Figure 7 shows a block diagram of an example computer system that can be used in conjunction with systems and methods according to embodiments of the present disclosure. Detailed Implementation

[0019] Electron microscopy utilizes a charged particle system to achieve high-resolution imaging by detecting signal electrons—electrons produced when an electron beam emitted by an electron emitter undergoes elastic and inelastic scattering with sample atoms. These signal electrons include backscattered electrons, secondary electrons, and primary electron beams that pass through the sample. In one example, electrons are emitted from an electrically heated cathode electrode. The emitted electrons are attracted to an anode located downstream of the cathode electrode, thus forming an electron beam that points towards and interacts with the sample. The signal electron current emitted from the electron beam interacting with the sample is measured by one or more electron detectors. This current is used to generate a high-resolution image of the sample.

[0020] Conventional charged particle systems may include optical elements for adjusting the beam profile of the charged particle beam (e.g., beam structure, shape, path energy, etc.), such as for correcting aberrations, shaping, and controlling the electron beam as it propagates within the beam column. For example, such conventional systems may include optical systems with multipole lenses and magnetic coils to adjust the beam profile of the charged particle beam. However, such conventional optical systems present certain challenges.

[0021] For example, using magnetic coils significantly increases the size of the optical system, thereby increasing the complexity of assembling and disassembling conventional optical systems. This increased complexity diminishes the advantages of replacing and moving multipole lenses and magnetic coils when conventional optical systems employ a modular design—that is, when multipole lenses and magnetic coils can be replaced with other multipole lenses and magnetic coils. For instance, because magnetic coils increase the size of optical elements, they are typically located outside the vacuum space where the electron beam propagates within the beam column, yet still require an interface connection to this vacuum space. Such interface connections are delicate, complicating the replacement process by ensuring proper alignment of the magnetic coil with the vacuum space. Therefore, for certain charged particle systems, an improved optical system may be more advantageous.

[0022] This disclosure addresses the aforementioned problems by providing a charged particle system with an optical inspection platform assembly comprising a housing for accommodating optical elements. The housing can be a single mechanical structure that allows the optical elements to be interchanged with other optical elements in a modular manner, thereby supporting a variety of different optical designs. For example, the optical elements can be interchanged with other optical elements within the housing to adjust the beam profile of a charged particle beam (e.g., an electron beam) propagating within the optical inspection platform assembly (e.g., to correct or adjust aberrations of the charged particle beam). The optical elements may also include standardized connection structures coupled to the housing to simplify the replacement process, reduce the complexity of adjusting the optical design of the optical inspection platform assembly, and decrease manufacturing costs. When the optical elements are mounted within the housing, they can be automatically aligned with the beam axis of the charged particle beam, further simplifying the replacement process. The optical elements may include electrostatic multipole elements, which significantly reduces the size of the optical inspection platform assembly. Therefore, the optical inspection platform assembly can be located within the vacuum space of the beam column, eliminating the need for precise interface connections to the vacuum space as required by conventional systems. This significantly reduces the complexity of adjusting optical elements within the optical inspection platform assembly, while simultaneously increasing the speed of replacing and / or adjusting multi-pole elements within the assembly. Therefore, this optical inspection platform assembly enhances the microscope's versatility by enabling rapid configuration for various applications.

[0023] Although the remainder of this specification will routinely refer to transmission electron microscopy (TEM), those skilled in the art will readily understand that the technique is not so limited. This design can be used with other types of charged particle microscopes, such as scanning electron microscopy (SEM), scanning transmission electron microscopy (STEM), focused ion beam (FIB) microscopy, dual-beam systems containing both an ion beam source and an electron beam source, reflection electron microscopy (REM), circuit editing microscopy, secondary ion mass spectrometry (SIMS) microscopy, etc. Therefore, this disclosure and claims should not be construed as limiting to any specific exemplary microscope discussed, but rather can be broadly applied to any number of electron microscopes that exhibit some or all of the electrical or chemical characteristics of the discussed examples.

[0024] Figure 1 is a schematic diagram of an exemplary charged particle system 100 according to some embodiments of the present disclosure. In the following description, for simplicity, details of the internal components and functions of the exemplary charged particle system 100 are omitted, and the description focuses on embodiments of the present disclosure. The exemplary charged particle system 100 includes a source section 102, a beam column 110, an objective lens section 115, and an imaging section 120. The charged particle system 100 is capable of electronic communication with a computer system 190, enabling the exchange of electronic information (e.g., data, measurement results, instructions, etc.) between the charged particle system 100 and the computer system 190.

[0025] Source section 102 may include electronic devices configured to power a charged particle source (e.g., a cathode electrode), which may include a high-voltage field emission source or other electron-emitting source to form a charged particle beam (e.g., an electron beam) and conduct it through a vacuum into beam column 110. Beam column 110 includes components for beam formation, including electromagnetic and / or electrostatic lenses and multiple apertures to control the properties of the electron beam. Beam column 110 components may include condenser lenses, objective lenses, projection lenses, aberration correctors, deflectors, astigmatism reducers, etc., and corresponding apertures. Objective section 115 may contain a sample that a charged particle beam can penetrate. Objective section 115 may include one or more types of detectors, such as X-ray detectors, secondary electron detectors, etc. Imaging section 120 may include one or more types of detectors, sensors, screens, and / or optics configured to generate images, spectra, and other data required for sample imaging and / or microanalysis. For example, the imaging segment may include a scintillator screen, binoculars, transmission electron microscopy (TEM) detectors (e.g., pixelated electron detectors, secondary electron detectors, cameras, etc.), segmented STEM detectors, and electron energy loss spectroscopy (EELS) spectrometers, etc.

[0026] Charged particle beams are typically characterized by beam current and accelerating voltage used to generate the beam, among other criteria. The beam current and accelerating voltage ranges can vary between instruments and are generally selected based on the material properties of the sample or the type of analysis being performed. However, typically, charged particle beams are characterized by energies from about 0.1 keV (e.g., for an accelerating voltage of 0.1 kV) to about 50 keV and beam currents from picoamperes to microamperes. The charged particle beam can be emitted along the beam axis (e.g., the Z-axis direction) from source section 102 and propagate via beam column 110 and objective section 115.

[0027] As mentioned above, conventional charged particle systems may include optical elements that can adjust the profile of the charged particle beam, such as those used to correct aberrations, shape, and control the electron beam. However, these conventional optical elements, including magnetic coils, significantly increase their size and thus place them outside the vacuum space of the beam column. Both of these factors increase the complexity of adjusting the optical elements in conventional charged particle systems, especially when the optical elements are designed modularly.

[0028] The charged particle system 100 may include an optical detection platform assembly 130 located within the beam column 110 to address the aforementioned problems. For example, in some embodiments, the optical detection platform assembly 130 may not include a magnetic coil, but instead include electrostatic optics. This can significantly reduce size, particularly the cross-sectional diameter, compared to conventional optics. Furthermore, because the optical detection platform assembly 130 is smaller, it can be located within a vacuum space 145 defined by the liner 140 within the beam column 110. This allows the optical detection platform assembly 130 to be more easily adjusted compared to conventional optics. Although the optical detection platform assembly 130 is shown upstream of the objective lens section 115 in the figures, in other embodiments, the optical detection platform assembly 130 and / or a second optical detection platform assembly may be located downstream of the objective lens section.

[0029] The vacuum within vacuum space 145 can be created by a vacuum pump (not shown in Figure 1) in fluid communication with the interior of liner 140. Vacuum space 145 helps minimize unwanted particles to avoid interfering with the propagation of the charged particle beam within liner 140. In other embodiments, there may be no liner, and the vacuum space may be defined by a beam column. Liner 140 may be made of one or more layers of material that can act as a magnetic shield to prevent external magnetic fields from interfering with vacuum space 145 (e.g., made of ferromagnetic materials), for example, preventing external magnetic fields from interfering with optical detection platform assembly 130.

[0030] Figure 2 illustrates an optical detection platform assembly 130 for a charged particle system 100. The optical detection platform assembly 130 may include a first optical support 220a, a second optical support 220b, a third optical support 220c, a fourth optical support 220d, and a fifth optical support 220e coupled to a housing 210. As will be discussed further below, the optical supports 220a, 220b, 220c, 220d, and 220e may house an optical element (e.g., a multipole element) and align these optical elements with each other. These optical elements may be aligned with the beam axis of the charged particle beam along a channel 212 defined by the housing 210, thereby allowing the charged particle beam to pass along the beam axis through the optical elements. The optical elements in each of the optical supports 220a, 220b, 220c, 220d, and 220e can adjust the beam profile of the charged particle beam for various purposes, such as correcting aberrations of the charged particle beam (e.g., path aberration, spherical aberration, etc.), shaping and controlling the electron beam, etc.

[0031] The optical inspection platform assembly 130 can be modularly designed, allowing the number and position of the optical supports 220a, 220b, 220c, 220d, and 220e within the housing 210 to be adjusted according to the desired charged particle beam profile. For example, the number of optical supports 220a, 220b, 220c, 220d, and 220e can be adjusted according to the desired beam profile. Therefore, although five optical supports 220a, 220b, 220c, 220d, and 220e are shown in the figure, in other embodiments, the optical inspection platform assembly can contain any number of optical supports, such as fewer or more than five (e.g., two, three, four, six, etc.). Furthermore, the positions of the optical supports 220a, 220b, 220c, 220d, and 220e can be adjusted to orientations different from those shown in Figure 2.

[0032] Optical supports 220a, 220b, 220c, 220d, and 220e can be coupled to multiple sets of openings defined by housing 210. Specifically, housing 210 can define multiple sets of first openings 214 and second openings 216. Each set of openings 214 and 216 can be coplanar along the XY plane and can accommodate a portion of the corresponding optical supports 220a, 220b, 220c, 220d, and 220e (e.g., arms 320a, 320b, and 320c of the first optical support 220a). For visual clarity, only a few openings 214 and 216 are marked with reference lines in Figure 2.

[0033] The housing 210 may define any number of opening groups 214, 216 along its length in the Z-axis direction, for example, more or less than the number shown in FIG. 2. The spacing between each group of openings 214, 216 may be approximately 1 mm to 15 mm, for example, approximately 3 mm to 12 mm, or approximately 6 mm to 9 mm, etc. Although each group of openings 214, 216 along the XY plane is shown as containing two openings 214, 216, in other embodiments, each group of openings may contain more than two openings, such as three, four, etc. In some embodiments, each optical bracket may have only one opening for coupling. The cross-sectional area of ​​the second opening 216 in the XY plane may be larger than that of the first opening 214. Due to this larger cross-sectional area, more portions of the corresponding optical brackets 220a, 220b, 220c, 220d, 220e may be located therein, as will be discussed further below. However, in other embodiments, the size of each opening may be similar. In still other embodiments, the size of the first opening may be larger than that of the second opening. The engagement of optical supports 220a, 220b, 220c, 220d, and 220e with the corresponding opening groups 214 and 216 will be described in more detail below.

[0034] Each optical support 220a, 220b, 220c, 220d, 220e may include any number of opening groups 214, 216 located between each optical support 220a, 220b, 220c, 220d, 220e. For example, the third optical support 220c and the fourth optical support 220d may not include any opening groups 214, 216 located between them. In another example, there may be two opening groups 214, 216 between the fourth optical support 220d and the fifth optical support 220e. Therefore, the relative spacing of each optical support (220a, 220b, 220c, 220d, 220e) can be adjusted according to the number of opening groups (214, 216) between them, if needed.

[0035] Figures 3A and 3B illustrate a first optical support 220a. It should be understood that the following description of the first optical support 220a also applies to the other optical supports 220b, 220c, 220d, and 220e. The first support 220a may include a base portion 310 defining an optical aperture 312 for accommodating an optical element 340. The first optical support 220a may include a first arm 320a, a second arm 320b, and a third arm 320c extending radially from the base portion 310. The three arms (320a, 320b, 320c) may be approximately equiangularly distributed in the XY plane (e.g., spaced approximately 120° apart, allowing deviations such as 10%, 5%, 2%, 1%, or complete equiangularity). The number of arms 320a, 320b, and 320c, and the approximately equal angle relationship between them, helps to center the optical element 340 along the central axis of the channel 212 of the housing 210, as will be discussed further below. However, in other embodiments, the arms may be at any angle to each other in the XY plane. Additionally or alternatively, the number of arms extending from the base portion may be more or less than three, such as one arm, two arms, four arms, etc.

[0036] Each arm 320a, 320b, 320c may include an arm body and a spring mechanism extending from the arm body to a distal end. Specifically, the first arm 320a may include a first arm body 322a and a first spring mechanism 324a extending from a first end 326a of the first arm body 322a; the second arm 320b may include a second arm body 322b and a second spring mechanism 324b extending from a second end 326b of the second arm body 322b; the third arm 320c may include a third arm body 322c and a third spring mechanism 324c extending from a third end 326c of the third arm body 322c. The spring mechanisms 324a, 324b, 324c may be cantilever springs, which are rotatable about their respective ends 326a, 326b, 326c and biased away from the arms 322a, 322b, 322c.

[0037] In other embodiments, the spring mechanism may be other types of springs, such as including other spring components coupled to the arm body (e.g., compression springs, torsion springs, leaf springs, etc.). In still other embodiments, the spring mechanism may extend from other parts of the corresponding arm body, not limited to the ends of the arm body, for example, extending along the middle portion of the arm body. In an alternative embodiment, the spring mechanism may be a leaf spring, such that the spring mechanism does not need to extend from the arm body to the distal end, but rather forms a leaf spring with both ends extending from the arm body. This leaf spring can be compressed towards the arm body along the central portion of the leaf spring. Using a leaf spring as the spring mechanism provides an alternative for mounting the first optical bracket, as will be discussed further below.

[0038] Spring mechanisms 324a, 324b, and 324c may be oriented toward the base portion 310, as will be further explained below, so that when arms 320a, 320b, and 320c are inserted into the corresponding openings 214 and 216 in the housing 210, spring mechanisms 324a, 324b, and 324c can slide more easily into the openings 214 and 216. However, in other embodiments, the orientation of spring mechanisms 324a, 324b, and 324c may vary depending on the desired orientation for insertion into the housing 210. For example, in other embodiments, one or more spring mechanisms may be oriented away from the base portion. In one example, one or more spring mechanisms may extend from the middle portion of the arm to the distal end in a direction away from the base portion.

[0039] Each arm body 322a, 322b, and 322c may be provided with an arm hole for accommodating the corresponding sphere. Specifically, the first arm body 322a may define a first arm hole 328a for accommodating the first sphere 330a; the second arm body 322b may define a second arm hole 328b for accommodating the second sphere 330b; and the third arm body 322c may define a third arm hole 328c for accommodating the third sphere 330c. The size and shape of the arm holes 328a, 328b, and 328c may be designed to accommodate the corresponding spheres 330a, 330b, and 330c, for example, in the form of a hemisphere, a trihedron, a cone, or a truncated cone. The spheres 330a, 330b, and 330c can be fixed within the arm holes 328a, 328b, and 328c by an adhesive (e.g., a vacuum-compatible adhesive), thereby restricting the movement of the spheres 330a, 330b, and 330c relative to the arms 322a, 322b, and 322c. In this way, pressure applied to the spheres 330a, 330b, and 330c along the Z-direction (e.g., by means of spring mechanisms 324a, 324b, and 324c) can also be applied to the arms 322a, 322b, and 322c and the base portion 310. Arms 322a, 322b, and 322c may define arm holes 328a, 328b, and 328c near the ends 326a, 326b, and 326c of each arm 322a, 322b, and 322c; however, in other embodiments, the arm holes may be defined at positions closer to the base portion than shown in Figure 3B. In still other embodiments, the arm may define a groove along its length, at least partially accommodating a sphere within the groove.

[0040] Spring mechanisms 324a, 324b, and 324c can be perpendicularly positioned on arms 322a, 322b, and 322c along the Z-axis to spheres 330a, 330b, and 330c. In this manner, spring mechanisms 324a, 324b, and 324c can be pressed down towards spheres 330a, 330b, and 330c, engaging with them. When spring mechanisms 324a, 324b, and 324c are engaged with spheres 330a, 330b, and 330c, arms 322a, 322b, and 322c can move, and the base portion 310 can move along the Z-axis away from spring mechanisms 324a, 324b, and 324c. As will be further explained below, this facilitates the engagement of spheres 330a, 330b, and 330c with other components.

[0041] Optical element 340 can be a multipole element capable of altering the beam profile of a charged particle beam. For example, the multipole element can be an electromagnetic element (e.g., capable of generating a magnetic field) or an electrostatic element (e.g., capable of generating an electric field) to change the beam profile of a charged particle beam propagating through the multipole element. Using an electrostatic element as the multipole element may be more advantageous because it requires less space and is less complex to manufacture; in contrast, electromagnetic elements typically require magnetic coils coupled to a vacuum fluid, as seen in conventional systems. Therefore, using an electrostatic element as the multipole element reduces the overall size of the optical detection platform assembly 130 and allows it to be located within the vacuum space 145 of the beam column 110. However, in other embodiments, the multipole element can be an electromagnetic element. Although optical element 340 is shown as a quadrupole in the figures, in other embodiments, the optical element can be a binary, hexapole, or higher-order multipole element. In some embodiments, the optical element may include charged particle lenses, such as one or more single lenses (or single-potential lenses). Such charged particle lenses can be electrostatic charged particle lenses or electromagnetic charged particle lenses.

[0042] Figures 4A-4C illustrate a first optical support 220a coupled to housing 210. As shown in Figure 4A, housing 210 may define a first recess 410a for receiving a first sphere 330a. The first recess 410a may partially define a first opening 214. As shown in Figure 4B, housing 210 may define a second recess 410b and a third recess 420c. Recesses 410b and 410c may partially define a second opening 216. The shapes of recesses 410a, 410b, and 410c may be designed as V-grooves formed by two intersecting planar surfaces on housing 210. However, in other embodiments, the recesses may have other shapes, such as spherical, conical, etc. When spheres 330a, 330b, and 330c are embedded in recesses 410a, 410b, and 410c respectively, the spheres 330a, 330b, and 330c may be located at a central position between the two intersecting planar surfaces. In other embodiments, the notches may have other shapes, such as partially cylindrical, partially spherical, etc. The recesses 410a, 410b, and 410c may be arranged in a direction toward the central axis of the channel 212. However, in other embodiments, the recesses may be arranged in a direction offset from the central axis of the channel. The recesses 410a, 410b, and 410c may be spaced approximately equiangularly from each other. As will be discussed below, this approximately equiangular relationship between the recesses 410a, 410b, and 410c helps to center the optical element 330 in the channel 212. In other embodiments, the housing may not have recesses.

[0043] The first spring mechanism 324a can be compressed to abut against the first ball 330a, while spring mechanisms 324b and 324c can be compressed to abut against balls 330b and 330c. The compression of balls 330a, 330b, and 330c by spring mechanisms 324a, 324b, and 324c pushes balls 330a, 330b, and 330c into corresponding grooves 410a, 410b, and 410c (and aligns arms 322a, 322b, and 322c and base portion 310 along the Z-axis towards grooves 410a, 410b, and 410c), thereby causing frictional engagement between balls 330a, 330b, and 330c and the intersecting surfaces defining grooves 410a, 410b, and 410c. The first spring mechanism 324a can be secured in this configuration via the first surface 414 that partially defines the first opening 214. Spring mechanisms 324b and 324c can be secured in this configuration via the second surface 416 that partially defines the second opening 216. In this way, the spring mechanisms 324a, 324b, and 324c help to securely fix the first optical support 220a within the housing 210.

[0044] In this configuration, optical element 330 can be located at the center of channel 212 (e.g., concentric with respect to the central axis of channel 212), allowing the charged particle beam to propagate through channel 212 and pass through the center of optical element 220. Other optical supports 220b, 220c, 220d, and 220e can be centered on housing 210 in a similar manner. In this way, all optical supports 220a, 220b, 220c, 220d, and 220e (and the corresponding optical element 340 for each of optical supports 220a, 220b, 220c, 220d, and 220e) can be aligned approximately concentrically with each other and with respect to channel 212. For example, each optical support (220a, 220b, 220c, 220d, 220) can be concentrically aligned with the central axis of channel 212, with a concentricity deviation of less than about 5 micrometers, 3 micrometers, 2 micrometers, 1 micrometer, or even zero.

[0045] The process of mounting optical supports 220b, 220c, 220d, and 220e to housing 210 facilitates maintaining the center alignment of optical supports 220b, 220c, 220d, and 220e. For example, to couple the first optical support 220a to housing 210, arms 320a, 320b, and 320c can be inserted into openings 214 and 216. Specifically, as shown in FIG4B, the first arm 320a and the base portion 310 are first inserted from outside housing 210 through the second opening 216 into channel 212 until the first arm 320a and the base portion 310 enter channel 212 from the second opening 216. Then, the first arm 320a is inserted from channel 212 into the first opening 214, while the other arms 320b and 320c are inserted into the second opening 216. When arms 320a, 320b, and 320c are inserted into the corresponding openings 214 and 216, spheres 330a, 330b, and 330c are also embedded into the corresponding grooves 410a, 410b, and 410c, respectively.

[0046] Since the arms 320a, 320b, and 320c are approximately equiangularly related to each other around the base portion 310 (therefore, the corresponding spheres 330a, 330b, and 330c are also approximately equiangularly related to each other), and the grooves 410a, 410b, and 410c are also approximately equiangularly related to the channel 212, when the arms 320a, 320b, and 320c are inserted into the corresponding openings 214 and 216 and the spheres 330a, 330b, and 330c are inserted into the corresponding grooves 410a, 410b, and 410c, the first optical support 220a can be centered with the channel 212. Specifically, when the first sphere 330a slides away from the channel 212 along the first groove 410a, since the grooves (410a, 410b, 410c) are distributed at a certain angle, the spheres (330b, 330c) in the other two grooves (410b, 410c) gradually deviate from the center lines of the other grooves 410b and 410c as they move inward towards the channel 212. As the spheres 330b and 330c deviate from the central axes of the grooves 410b and 410c, they begin to connect with the intersecting plane surfaces of the outer shell 210 that defines the grooves 410b and 410c in the X and Y directions, generating gradually increasing pressure. Therefore, when the first arm 320a is inserted into the first opening 214 and the first sphere 330a slides a certain distance along the first groove 410a, the movement of the other spheres 330b and 330c is restricted in the XY plane by being pressed against the intersecting plane surfaces of the outer shells 210 that define the grooves 410b and 410c. When the movement of the spheres 330b and 330c in the XY plane is restricted, and the linear movement of the first sphere 330a in the first groove 410a is also restricted, the first optical support 220a (and the corresponding optical element 330) can be centered in the channel 212. This movement restriction indicates that the spheres 330a, 330b, and 330c are aligned and centered.

[0047] When the first arm 320a is inserted into the first opening 214, the first spring mechanism 324a is pressed against the ball 330a by the first surface 414, while the spring mechanisms 324b and 324c are pressed against the balls 330b and 330c by the second surface 416 that partially defines the second opening 216. The spring mechanisms 324a, 324b, and 324c push the balls 330a, 330b, and 330c into the corresponding grooves 410a, 410b, and 410c, applying further pressure to the balls 330a, 330b, and 330c, thereby enhancing the frictional engagement between the balls 330a, 330b, and 330c and the grooves 410a, 410b, and 410c, as previously described. When the spring mechanisms 324a, 324b, and 324c push the spheres 330a, 330b, and 330c into the grooves 410a, 410b, and 410c, the arms 322a, 322b, and 322c, as well as the base portion 310, are also pushed into the grooves 410a, 410b, and 410c along the Z-direction. This engagement and additional pressure further reduce the movement of the first optical support 220a in the XY plane after it is centered in the housing 210.

[0048] Before inserting the spring mechanisms 324b and 324c into the second opening 216, the spring mechanisms 324b and 324c can be pre-pressed downwards so that the distal ends of the spring mechanisms 324b and 324c can slide smoothly into the second opening 216 without being jammed by the outer surface of the housing 210. However, as mentioned above, in other embodiments, the second and third spring mechanisms can be oriented away from the base portion. This can be advantageous because when mounting the first optical bracket, the second and third spring mechanisms can slide more easily under the second surface partially defining the second opening without pre-compressing the second and third spring mechanisms before inserting them into the second opening. In this way, all spring mechanisms can be inserted into the corresponding first and second openings without being jammed by the outer surface of the housing. In another embodiment, the second and third spring mechanisms can be leaf springs without distal ends extending from the corresponding arm body, instead of cantilever springs. Because the leaf spring does not contain a distal end that could get stuck on the surface of the housing, it can be compressed to push the sphere (and the corresponding arm and base portions) as the optical bracket slides into the housing, without the need to pre-compress the leaf spring.

[0049] The first optical support 220a can be decoupled and disassembled from the housing 210 by pushing the first arm 320a out of the first opening 214 and retracting it into the channel 212. When the first arm 320a is pushed into the channel 212, the other arms 320b and 320c can be pushed out of the housing 210 from the second opening 216. The first arm 320a can then be pushed out of the housing 210 from the second opening 216. Before pushing the first arm 320a out of the second opening 216, the first spring mechanism 324a can be compressed to prevent the distal end of the first spring mechanism 324a from jamming against the inner surface of the housing 210 defining the channel 212. However, in other embodiments, the first spring mechanism may be oriented away from the base portion, and / or the first spring mechanism may be a leaf spring, so that compression of the first spring mechanism is not required before pushing it out of the second opening.

[0050] Based on the above process, the first optical support 220a can be inserted into or removed from the housing 210 as needed. Other optical supports 220b, 220c, 220d, and 220e can be inserted into or removed from the housing 210 in a similar manner. In this way, the optical supports 220a, 220b, 220c, 220d, and 220e can be easily inserted and removed (e.g., interchanged with other optical supports or moved to different positions on the housing 210) while always remaining aligned and fixed on the central axis of the channel 212. This modular design enhances the ability of the optical inspection platform assembly 130 to form a charged particle beam with a specific and customizable beam profile. In some embodiments, the entire optical inspection platform assembly 130 can be removed and replaced with another optical inspection platform assembly with a different optical support configuration.

[0051] The housing 210, and the base portion 310 and arms 320a, 320b, 320c, 220d, 220e of the optical supports 220a, 220b, 220c can be made of metallic or plastic materials, such as non-magnetic materials. For example, metallic materials may include copper, aluminum, brass, stainless steel, gold, etc. Plastic materials may include polyethylene, polypropylene, polytetrafluoroethylene, etc.

[0052] As described above, the housing 210 can define the recesses 410a, 410b, and 410c to have other shapes. For example, Figure 5An optical inspection platform assembly 530 with a housing 510 is shown, the housing 510 defining a first recess 590a for receiving a first sphere 330a, positioned similarly to the cross-sectional plane in FIG. 4C. The first recess 590a may be spherical, its size and shape adapted to receive the first sphere 330a. A first spring mechanism 324a may push the first sphere 330a into the spherical first recess 590a, thereby preventing the first sphere 330a from moving in the XY plane until a force exceeding a threshold is applied to push the first sphere 330a out of the first recess 590a. Although not shown in FIG. 5, other recesses defined by the housing 510 may have similar spherical shapes corresponding to other spheres. The housing 510 may define the position of the spherical recesses such that once the sphere is placed into the spherical recess, the first optical support 220a may be aligned with the channel 212 (e.g., aligned with the beam axis of the charged particle beam). In this manner, the first optical support 220a can be installed within the housing 510, as described above, until the sphere of the first optical support 220a engages with the corresponding spherical groove, similar to the engagement of the first sphere 330a with the spherical first groove 590a. This engagement of the sphere and groove in the optical inspection platform assembly 530 ensures alignment of the first optical support 220a with the channel 212, while providing the user with a tactile experience of alignment between the first optical support 220a and the channel 212. In other embodiments, the groove may have a conical shape.

[0053] Figure 6 shows an example flowchart for the image generation process 600. Unless otherwise stated, the flowchart in Figure 6 will be described with reference to the charged particle system 100 shown in Figure 1 and the optical detection platform components shown in Figures 4A-4C. At least some of the following operations of the charged particle system 100 components can be performed under the control of or by the computer system 190. It should be understood that, unless otherwise noted below, features ending with similar reference numerals are similar to those discussed above.

[0054] Block 610 may include a charged particle beam emitted from a charged particle source along the beam axis, passing through an optical chamber, and reaching a sample. For example, the charged particle beam (e.g., an electron beam) may be emitted from source section 102, pass through beam column 110, and act on the sample in objective section 115. Before propagating to the sample, the charged particle beam may pass along the beam axis through optical detection platform assembly 130 located in vacuum space 145 of beam column 110.

[0055] As shown in Figure 2, the optical inspection platform assembly 130 may include a housing 210 and optical supports 220a, 220b, 220c, 220d, and 220e coupled to the housing 210 within openings 214 and 216. Each optical support 220a, 220b, 220c, 220d, and 220e may include an optical element 340 (e.g., a multipole element) substantially aligned with a channel 212 of the housing 210. Turning to Figures 4A-4C, the first optical support 220a may include a base portion 310 and arms 320a, 320b, and 320c extending from the base portion 310. Through the frictional engagement of the spheres 330a, 330b, 330c positioned between the spring mechanisms 324a, 324b, 324c and the grooves 410a, 410b, 410c, the arms 320a, 320b, 320c can be coupled to the openings 214, 216. This structural configuration between the first optical support 220a and the housing 210 allows the optical element 340 of the first optical support 220a to be aligned with the central axis of the channel 212 (e.g., the beam axis of a charged particle beam). In other embodiments, turning to FIG5, the first optical support 220a can also be aligned with the central axis of the channel 212 by pushing the sphere 330a into the spherical groove 590a via the first spring mechanism 324a. Returning to Figures 4A-4C, the remaining optical supports 220b, 220c, 220d, and 220e can be installed in a similar manner. In this way, all optical supports 220a, 220b, 220c, 220d, and 220e can be aligned with the central axis of channel 212, so that the beam profile of the charged particle beam as it passes through the optical detection platform assembly 130 before propagating to the sample can be adjusted by the optical elements 340 of each optical support 220a, 220b, 220c, 220d, and 220e.

[0056] Box 620 may include the detection of signal electrons emitted from the sample by the interaction of a beam of charged particles with the sample.

[0057] Box 630 may include signal-based electronically generated images. After image generation, one or more optical supports 220a, 220b, 220c, 220d, 220e can be removed from housing 210 and replaced with other optical supports and / or repositioned along housing 210. In some embodiments, the entire optical inspection platform assembly 130 may be removed and replaced with another optical inspection platform assembly with a different optical support configuration.

[0058] Any computer system mentioned herein may use any suitable number of subsystems. The computer system 710 shown in Figure 7 illustrates an example of such a subsystem; this system is an example of computer system 190. In some embodiments, the computer system includes a single computer device, wherein the subsystem may be a component of the computer device. In other embodiments, the computer system may include multiple computer devices, each of which is a subsystem with internal components. The computer system may include desktop and laptop computers, tablets, mobile phones, and other mobile devices.

[0059] The subsystems shown in Figure 7 are interconnected via system bus 775. Other subsystems are also shown, such as printer 774, keyboard 778, storage device 779, and monitor 776 (e.g., LED display) coupled to display adapter 782. Peripheral devices and input / output (I / O) devices are connected to the computer system via I / O controller 771 and can be connected to the computer system in various ways known in the art, such as I / O port 777 (e.g., USB, FireWire®). For example, I / O port 777 or external interface 781 (e.g., Ethernet, Wi-Fi, etc.) can be used to connect computer system 710 to a wide area network, such as the Internet, a mouse input device, or a scanner. The interconnection via system bus 775 enables central processing unit 773 to communicate with the subsystems and control the execution of multiple instructions from system memory 772 or storage device 779 (e.g., fixed disk, such as hard disk or optical disk), as well as the exchange of information between subsystems. System memory 772 and / or storage device 779 may contain computer-readable media. Another subsystem is a data acquisition device 785, such as a camera, microphone, accelerometer, etc. Any data mentioned herein may be output from one component to another and may be output to a user.

[0060] A computer system may include multiple identical components or subsystems, for example, connected together via an external interface 781, an internal interface, or removable storage devices that can be removed from one component and connected to another. In some embodiments, the computer system, subsystem, or device may communicate over a network. In such cases, one computer may be considered a client and another a server, each of which may be part of the same computer system. A client and a server may each contain multiple systems, subsystems, or components.

[0061] Various aspects of this embodiment can be implemented in a modular or integrated manner, in the form of control logic, using hardware circuitry (e.g., application-specific integrated circuits or field-programmable gate arrays) and / or computer software stored in memory with a general-purpose programmable processor; therefore, the processor may include memory storing software instructions for configuring the hardware circuitry, and an FPGA or ASIC having configuration instructions. As used herein, the processor may include a single-core processor, a multi-core processor on the same integrated chip, or multiple processing units on a single circuit board or networked, as well as dedicated hardware. Based on the disclosure and teachings provided herein, those skilled in the art will recognize and understand other ways and / or methods of implementing embodiments of this disclosure using hardware and combinations of hardware and software.

[0062] Any software component or function described in this application may be implemented as software code, using any suitable computer language, such as Java, C, C++, C#, Objective-C, Swift, or a scripting language such as Perl or Python, and executed by a processor using, for example, conventional or object-oriented techniques. The software code may be stored as a set of instructions or commands on a computer-readable medium for storage and / or transmission. Suitable non-transitory computer-readable media may include random access memory (RAM), read-only memory (ROM), magnetic media (such as hard disks or floppy disks) or optical media (such as optical discs (CDs) or DVDs (Digital Versatile Optical Discs) or Blu-ray discs), flash memory, etc. The computer-readable medium may be any combination of such devices. Furthermore, the order of operations may be rearranged. A process may terminate upon completion of its operations, but there may also be other steps not included in the accompanying drawings. A process may correspond to a method, function, procedure, subroutine, subprogram, etc. When a process corresponds to a function, its termination may correspond to the function returning to the calling function or the main function.

[0063] Such programs can also be encoded and transmitted using carrier signals suitable for transmission over wired, fiber optic, and / or wireless networks (including the Internet) conforming to various protocols. Therefore, computer-readable media can be created using data signals encoded with such programs. Computer-readable media encoded with program code can be packaged with compatible devices or provided separately from other devices (e.g., downloaded via the Internet). Any such computer-readable media can reside on or within a single computer product (such as a hard drive, CD, or an entire computer system) and can exist on or within different computer products within a system or network. A computer system may include a monitor, printer, or other suitable display for providing a user with any of the results mentioned herein.

[0064] Any method described herein can be performed wholly or partially by a computer system including one or more processors configured to perform these steps. Any operation performed by the processor (e.g., alignment, determination, comparison, computation) can be performed in real time. The term "real time" can refer to a computational operation or process completed within a time limit. The time limit can be 1 minute, 1 hour, 1 day, or 7 days. Therefore, embodiments can relate to a computer system configured to perform the steps of any method described herein, which may have different components performing the respective steps or a corresponding set of steps. Although methods are presented as numbered steps, the method steps herein can be performed simultaneously or at different times, or in different orders. Furthermore, portions of these steps can be used in conjunction with portions of other steps from other methods. And, all or part of the steps can be optional. Furthermore, any step of any method can be performed using modules, units, circuits, or otherwise of a system that performs these steps.

[0065] In the foregoing description, embodiments of this disclosure have been described with reference to numerous specific details, which may vary depending on the embodiments. Therefore, the description and drawings should be considered illustrative rather than restrictive. The unique and exclusive indication of the scope of this disclosure, and what the applicant intends to define as the scope of this disclosure, is the literal and equivalent scope of the claims granted in the specific form (including any subsequent amendments) published in this application. Specific details of particular embodiments may be combined in any suitable manner without departing from the spirit and scope of the embodiments of this disclosure.

[0066] In addition, spatially relative terms such as “bottom” or “top” may be used to describe the relationship of one element and / or feature to another, as shown in the figures. It should be understood that, in addition to the orientations depicted in the figures, the spatially relative terms are also intended to cover different orientations of the device during use and / or operation. For example, if the device in the figures is flipped, an element described as the “bottom” face may be oriented “above” other elements or features. The device may be oriented in other ways (e.g., rotated 90° or in other orientations), and the spatially relative descriptors used herein can therefore be interpreted.

[0067] The terms “and,” “or,” and “and / or” as used herein may include a variety of meanings, which are expected to depend at least in part on the context in which they are used. Generally, “or,” when used to relate a series, such as A, B, or C, means A, B, and C, used herein in an inclusive sense, and A, B, or C, used herein in an exclusive sense. Furthermore, the term “one or more,” as used herein, may be used to describe any feature, structure, or property in the singular form, or may be used to describe some combination of features, structures, or properties. However, it should be noted that this is merely an illustrative example, and the claimed subject matter is not limited to this example. Additionally, the term “at least one,” when used to relate a series, such as A, B, or C, can be interpreted as meaning any combination of A, B, and / or C, such as A, B, C, AB, AC, BC, AA, AAB, ABC, AABBCCC, etc.

[0068] Throughout this specification, references to "an example," "an example," "some examples," or "exemplary implementation" mean that the specific feature, structure, or characteristic associated with the feature and / or example may be included in at least one feature and / or example of the subject matter of the claims. Therefore, the phrases "in an example," "an example," "some examples," "in some implementations," or other similar phrases used throughout this specification do not necessarily refer to the same feature, example, and / or limitation. Furthermore, a specific feature, structure, or characteristic may be combined in one or more examples and / or features.

[0069] In some implementations, operation or processing may involve the physical manipulation of physical quantities. Generally, although not always, such quantities may take the form of electrical or magnetic signals that can be stored, transmitted, combined, compared, and further manipulated. It has proven convenient, primarily for common reasons, to refer to such signals as bits, data, values, elements, symbols, characters, terms, numbers, numerals, etc. However, it should be understood that all such terms or similar terms are associated with the appropriate physical quantity and are merely convenient designations. Unless otherwise expressly stated, as will be apparent from the discussion herein, it should be understood that throughout this specification, discussions using terms such as “processing,” “calculation,” “operation,” “determination,” etc., refer to the actions or processes of a particular device such as a dedicated computer, dedicated computing device, or similar dedicated electronic computing device. Thus, in the context of this specification, a dedicated computer or similar dedicated electronic computing device is capable of manipulating or transforming signals that are generally reproduced as physical electronic or magnetic quantities in the memory, registers, or other information storage devices, transmission devices, or display devices of the dedicated computer or similar dedicated electronic computing device.

[0070] In the foregoing detailed description, numerous specific details have been set forth to provide a thorough understanding of the claimed subject matter. However, those skilled in the art will understand that the claimed subject matter can be practiced without these specific details. In other instances, methods and apparatus known to a person of ordinary skill have not been described in detail so as not to obscure the claimed subject matter. Therefore, it is intended that the claimed subject matter not be limited to the specific examples disclosed, but rather that such claimed subject matter may also include all aspects falling within the scope of the appended claims and their equivalents.

Claims

1. An optical detection platform assembly, configured to be located within the optical chamber of a charged particle system, comprising: A shell with multiple openings and a channel that defines the beam axis of charged particles; as well as Multiple optical supports, including: Each of the plurality of optical supports includes a base portion and one or more arms extending from the base portion; The one or more arms of each optical bracket are detachably mounted within the first opening of the plurality of openings; The base portion of each optical bracket is configured to accommodate multipole elements; and The base portion of each optical bracket is located within the channel, such that each multipole element is aligned with each other along the beam axis.

2. The optical inspection platform assembly of claim 1, wherein the one or more arms comprise a plurality of arms.

3. The optical inspection platform assembly according to claim 2, wherein the first arm of the plurality of arms is detachably mounted in the first opening, and the second arm of the plurality of arms is detachably mounted in the second opening of the plurality of openings.

4. The optical inspection platform assembly according to claim 3, wherein the cross-sectional area of ​​the second opening is greater than the cross-sectional area of ​​the first opening.

5. The optical inspection platform assembly of claim 4, wherein the third arm of the plurality of arms is detachably mounted within the second opening.

6. The optical inspection platform assembly of claim 1, wherein each of the plurality of optical supports comprises a sphere capable of accommodating one or more arms.

7. The optical inspection platform assembly of claim 6, wherein one or more arms include a spring mechanism configured to engage with a ball.

8. The optical inspection platform assembly according to claim 7, wherein the spring mechanism is a cantilever spring or a leaf spring.

9. The optical inspection platform assembly of claim 6, wherein the housing defines a recess configured to accommodate a sphere.

10. The optical inspection platform assembly of claim 1, wherein the multipole element comprises an electrostatic multipole element.

11. The optical inspection platform assembly of claim 10, wherein the electrostatic multipole element comprises one or more electrostatic single lenses.

12. A charged particle system, comprising: A charged particle source, configured to emit a beam of charged particles along the beam axis; as well as An optical chamber in fluid communication with the charged particle source, wherein the optical chamber includes an optical detection platform assembly comprising: A housing with multiple openings and a channel aligned with the beam axis; An optical support includes a base portion and one or more arms extending from the base portion, wherein a first arm of the one or more arms is coupled to the housing within a first opening of a plurality of openings, and the base portion is located within a channel; and A multipole element housed in the base portion and aligned with the beam axis.

13. The charged particle system according to claim 12, wherein: The one or more arms include multiple arms; and The first arm of the plurality of arms is detachably mounted in the first opening, and the second arm of the plurality of arms is detachably mounted in the second opening of the plurality of openings.

14. The charged particle system of claim 13, wherein each of the plurality of arms is distributed approximately at equal angles to each other around the base portion.

15. The charged particle system according to claim 12, wherein: The optical chamber defines a vacuum space and is configured to be in a vacuum state; and The optical detection platform is located within this vacuum space.

16. The charged particle system of claim 12, wherein each of the plurality of optical supports comprises a sphere capable of accommodating one or more arms.

17. The charged particle system of claim 16, wherein one or more arms include a spring mechanism configured to engage with a sphere.

18. The charged particle system of claim 16, wherein the outer shell defines a recess configured to accommodate a sphere.

19. The charged particle system of claim 12, wherein the multipole element comprises an electrostatic multipole element.

20. An optical support configured in an optical detection platform assembly of a charged particle system. include: Multiple spheres; The base portion that defines the optical aperture; Multiple arms extend from the base, among which: Each of the plurality of arms defines an arm hole and includes a lever mechanism; Each of the plurality of spheres is located within the aperture of each arm; and The lever mechanism of each arm is configured to engage with a ball; and Optical elements housed within the optical opening.

Images