X-ray analysis system with focused x-ray beam and non-x-ray microscopy

Abstract

An apparatus includes an x-ray optical system configured to receive x-rays from an x-ray source to focus at least some of the x-rays to form a focused x-ray beam and to irradiate a portion of a sample with the focused x-ray beam. The focused x-ray beam has a depth of focus and a focused x-ray spot at the sample. The apparatus further includes a microscope having an objective lens configured to receive and focus light from the portion of the sample. The objective lens has an object plane and a field of view. The object plane is within a range centered at the depth of focus of the focused x-ray beam, the range has a width ten times the depth of focus, and the focused x-ray spot is within the field of view of the objective lens.

Description

Technical Field

[0001] Priority Claim

[0002] This application claims priority to U.S. Provisional Application No. 63 / 618,770, filed January 8, 2024, the entire contents of which are incorporated herein by reference.

[0003] This application generally relates to X-ray analysis and / or microscopy systems utilizing a combination of X-ray and non-X-ray probes. Background Technology

[0004] X-ray microprobes, which use a focused X-ray beam for excitation (e.g., micro-X-ray fluorescence analysis and X-ray-assisted device modification) and detection (e.g., micro-X-ray diffraction), offer powerful analytical and characterization capabilities. An optical microscope is typically used to locate the region of interest for the X-ray microprobe or complementary information (e.g., NIR, optical, Raman, etc.). X-ray microprobes and optical microscopes are often two independent / separate systems that utilize mechanical motion to align an optical image with a focused X-ray beam, leading to potential registration errors from mechanical motion and drift over time. Aligning a small focused X-ray beam (e.g., less than 30 micrometers full width at half maximum (FWHM); less than 5 micrometers (FWHM); less than 2 micrometers (FWHM); less than 1 micrometer (FWHM)) with an optical image with better positioning accuracy than 4000 nm (e.g., better than 3000 nm; better than 500 nm; within 150 nm) over an extended time without vibration / thermal drift can be particularly challenging. Summary of the Invention

[0005] In a particular embodiment, an apparatus includes an X-ray optical system configured to receive X-rays from an X-ray source and focus at least some of the X-rays to form a focused X-ray beam and irradiate a portion of a sample with the focused X-ray beam. The focused X-ray beam has a depth of focus and a focused X-ray spot at the sample. The apparatus further includes a microscope including an objective lens configured to receive and focus light from the portion of the sample. The objective lens has an object plane and a field of view. The object plane is within a range centered on the depth of focus of the focused X-ray beam, the range having a width ten times the depth of focus, and the focused X-ray spot is within the field of view of the objective lens.

[0006] In a particular embodiment, an apparatus includes an x-ray optical system configured to receive x-rays from an x-ray source and focus at least some of the x-rays to form a focused x-ray beam and irradiate a portion of a sample with the focused x-ray beam. The focused x-ray beam has a depth of focus and a focused x-ray spot at the sample. The apparatus further includes a microscope objective configured to receive and focus light from the portion of the sample. The objective has an optical axis, and the x-ray optical system has an x-ray propagation axis tilted relative to the optical axis. The objective has an object plane and a field of view. The object plane is within a range centered on the depth of focus of the focused x-ray beam, the range having a width ten times the depth of focus, and the focused x-ray spot is within the field of view of the objective.

[0007] In a particular embodiment, an apparatus includes at least one x-ray optics configured to receive x-rays from an x-ray source and to focus at least some of these x-rays to form a focused x-ray beam, which is then used to irradiate a portion of a sample. The focused x-ray beam has a depth of focus and a focused x-ray spot at the sample. The apparatus further includes an objective lens configured to receive and focus light from the portion of the sample. The objective lens has an optical axis, and the at least one x-ray optics has an x-ray propagation axis substantially parallel to and displaced from the optical axis. The objective lens has an object plane and a field of view. The object plane is within a range centered on the depth of focus of the focused x-ray beam, the range having a width ten times the depth of focus, and the focused x-ray spot is within the field of view of the objective lens. Attached Figure Description

[0008] Figure 1 An example device is schematically illustrated according to a specific implementation described herein.

[0009] Figure 2 An example objective lens is schematically illustrated according to a particular embodiment described herein.

[0010] Figure 3 A schematic illustration of an example reflective microscope including a reflector according to a specific embodiment described herein.

[0011] Figure 4 A schematic illustration of an example microscope configured for dark-field correlation imaging according to a specific embodiment described herein.

[0012] Figure 5 A portion of a string of optical elements according to a particular embodiment described herein is illustrated schematically.

[0013] Figure 6 This illustration schematically depicts another example device based on a particular implementation described herein.

[0014] Figure 7A An exemplary apparatus having at least one x-ray optics tilted relative to an objective lens, according to a particular embodiment described herein, is schematically illustrated.

[0015] Figure 7B Schematic illustration of the correspondence to a specific implementation described herein Figure 7A A top view of the sample location with a focused X-ray beam and reflected light. Detailed Implementation

[0016] The specific embodiments described herein provide an apparatus comprising a correlation (e.g., non-X-ray; visible light; infrared; near-infrared light) microscope and an X-ray focusing system, wherein the field of view of the correlation microscope and the focused X-ray beam of the X-ray focusing system are simultaneously co-located (e.g., at least partially overlap). Previously, this co-location was not possible due to the limited working distance of conventional X-ray focusing systems (e.g., multi-capillary lenses) and due to the size of the microscope objectives and the geometry of the multi-capillary lenses (both may have a relatively large outer diameter combined with a short working distance to achieve a small focal point (e.g., in the range of 2 mm to 3 mm)).

[0017] In certain embodiments, the apparatus includes an on-axis X-ray illumination detection / measurement system, a bright-field / dark-field optical microscopy alignment system, an X-ray assist device alteration (XADA) system, and / or an X-ray fluorescence (XRF) system. In certain embodiments, the apparatus further includes components (e.g., a stage; a motor) for aligning the object plane of an objective of the correlation microscope within the depth of focus of the focused X-ray beam (e.g., to ensure the focused X-ray spot is within the field of view of the correlation microscope). In certain embodiments, the correlation microscope comprises at least a bright-field visible light microscope, a dark-field visible light microscope, a near-infrared (NIR) microscope, an infrared microscope, or a combination of these methods.

[0018] In a particular embodiment, an apparatus includes a microscope configured to receive light (e.g., visible light; infrared light; near-infrared light) propagating along an optical axis and an X-ray focusing system configured to emit a focused X-ray beam along an X-ray propagation axis. The apparatus is configured to simultaneously position the field of view of the microscope and the focused X-ray beam. For example, the object plane of the microscope may be within the depth of focus of the focused X-ray beam, and the focused X-ray beam may be within the field of view of the microscope. In a particular embodiment, the X-ray propagation axis is substantially collinear with respect to at least a portion of the optical axis (e.g., an angle substantially equal to 0 degrees) or has a small angle (e.g., less than 30 degrees; less than 10 degrees; less than 3 degrees). For example, the focused X-ray beam and the optical axis may be substantially collinear with each other or on the axis.

[0019] In certain embodiments, the device includes a mirror (e.g., in the beam path) configured to reflect light away from the x-ray propagation axis (e.g., greater than 30 degrees; greater than 60 degrees; greater than 90 degrees). In certain embodiments, the mirror is configured to allow the focused x-ray beam to propagate through it (e.g., having a transmission efficiency greater than 70%; greater than 25%; greater than 10%). For example, a portion of the mirror may include an aperture or a thin solid material positioned on the x-ray propagation axis through which the focused x-ray beam propagates.

[0020] Figure 1 An exemplary device 10 according to a particular embodiment described herein is schematically illustrated. In this particular embodiment, device 10 includes a multimode lighting device. Figure 1 As shown, the device 10 includes an x-ray optical system 20 configured to receive x-rays 22 from an x-ray source 24 and to focus at least some of the x-rays 22 to form a focused x-ray beam 26, which is used to irradiate a portion of a sample 5. The focused x-ray beam 26 has a depth of focus and a focused x-ray spot 28 at the sample 5. The device 10 further includes a microscope 30 including an objective lens 40 configured to receive and focus light 34 (e.g., visible light, infrared light, and / or near-infrared light) from that portion of the sample 5. At least a portion of the x-ray optical system 20 is positioned within the objective lens 40. The objective lens 40 has an object plane and a field of view, the object plane being a range centered on the depth of focus of the focused x-ray beam 26, the range having a width ten times the depth of focus, and the focused x-ray spot 28 being within the field of view of the objective lens 40.

[0021] In a particular embodiment, the X-ray optical system 20 and the microscope 30 are rigidly attached to each other (e.g., after the X-ray optical system 20 and the microscope 30 have been aligned with each other) to ensure stable positioning. In a particular embodiment, the X-ray optical system 20 is rigidly attached to the objective lens 40. For example, the X-ray optical system 20 and the microscope 30 can be attached to each other via an adjustable alignment mechanism (e.g., one or more recentering screws; a stage with focus adjustment and an x / y stage for moving the X-ray optical system 20 relative to the sample 5 to position the region of interest). The alignment mechanism can be adjusted to compensate for alignment deviations attributable to temperature changes (e.g., due to changes in light intensity or brightness) and maintain alignment (e.g., to micrometer or submicrometer resolution).

[0022] In a particular embodiment, the x-ray optical system 20 is configured to receive at least some x-rays 22 propagating along an x-ray propagation axis 23 from an x-ray source 24 and guide a focused x-ray beam 26 to propagate along the x-ray propagation axis 23 to the sample 5. The x-ray optical system 20 may include at least one hollow capillary x-ray optic device 21 (e.g., a tube) having an inner surface that reflects at least some of the x-rays 22 through total external reflection (TER). For example, the inner surface may include glass that is uncoated or coated with at least one high atomic mass density material (e.g., Cr, W, Mo, Pt, Ir) or a multilayer coating (e.g., including periodic layers of alternating high and low atomic mass density materials (such as Cr / C, W / C, Mo / Si)). In a particular embodiment, the inner surface profile (e.g., in a plane including or parallel to a longitudinal axis of the x-ray optic device 21 and / or the x-ray propagation axis 23) includes at least one segment of a quadratic surface shape (e.g., an ellipsoid; a hyperbola; a parabola). For example, the inner surface profile may have an elliptical shape, and at least one X-ray optic device 21 may be positioned such that the X-ray source 24 is positioned at a first focal point of the ellipse and the focused X-ray spot 28 (e.g., the region of interest in sample 5) is positioned at a second focal point of the ellipse. The inner surface profile may be shaped to reflect X-rays 22 at a cutoff angle within a predetermined range (e.g., 5 keV to 10 keV; less than 1 keV; 1 keV to 5 keV; 5 keV to 6 keV; 5 keV to 8 keV; less than 10 keV; less than 30 keV). In a particular embodiment, at least one x-ray optic 21 is integrated with (e.g., attached to) the objective lens 40 (e.g., at least partially within the objective lens 40), while in certain other embodiments, at least one x-ray optic 21 has a sufficiently long working distance and the objective lens 40 has a sufficiently short length such that the objective lens 40 is positioned between at least one x-ray optic 21 and the sample 5 (e.g., at least one x-ray optic 21 is positioned "behind" the objective lens 40 on the x-ray propagation axis 23). In a particular embodiment, at least one x-ray optic 21 has a working distance in the range of greater than 10 mm (e.g., greater than 20 mm; greater than 30 mm; greater than 40 mm) and is co-registered with the optical axis 41 of the objective lens 40 such that the light 34 received by the objective lens 40 originates from the same spot of the sample 5 as the spot of light irradiated by the focused x-ray beam 26 (e.g., focused x-ray spot 28).

[0023] In a particular embodiment, at least one x-ray optics 21 includes first and second reflective (e.g., specular) parabolic segments (e.g., a "double parabolic" configuration) such that the first parabolic segment collimates at least some x-rays 22 diverging from the x-ray source 24 (e.g., placed at a virtual focal point of the first parabolic segment), and the second parabolic segment receives and focuses the collimated x-rays onto a spot (e.g., a point) at the object plane of the objective lens 40 (e.g., at or on sample 5). This double parabolic configuration can be achieved by an x-ray optics system 20 including a single x-ray optics 21 (e.g., a single tube) or a plurality (e.g., two) x-ray optics 21 (e.g., two tubes) whose longitudinal axes are aligned with each other.

[0024] Other examples of at least one x-ray optics 21 include (but are not limited to): double parabolic segments and Wolter optics (e.g., including hyperbolic, parabolic, and / or parabolic / ellipsoidal segments). For example, at least one x-ray optics 21 may include: a first reflective (e.g., specular) hyperbolic body configured to collect at least some of the x-rays 22 emitted from the x-ray source 24 (e.g., placed at a virtual focal point of the first reflective hyperbolic body); and a second reflective (e.g., specular) ellipsoid configured to collect and focus some of the x-rays collected by the hyperbolic body onto a spot of light at the object plane of the objective lens 40 (e.g., at or on sample 5). In another example, the order of the hyperbolic body and the ellipsoid is reversed. In another example, at least one x-ray optics device 21 may include: a first reflective (e.g., specular) hyperbolic / parabolic pair configured to collimate at least some of the x-rays 22 emanating from the x-ray source 24 (e.g., placed at a virtual focal point of the first specular hyperbolic / parabolic pair); and a second reflective (e.g., specular) hyperbolic / parabolic pair configured to focus the collimated x-rays 22 onto a spot of light at the object plane of the objective lens 40 (e.g., at or on the sample 5). In a particular embodiment, the x-ray optics system 20 includes at least one central beamstop (not shown) comprising a high atomic mass density material (e.g., tungsten) configured to attenuate (e.g., block; prevent) non-reflective x-rays propagating from the x-ray source 24 to the sample 5.

[0025] As used herein, the term "depth of focus" refers to a region extending a distance along the x-ray propagation axis 23 centered on the location where the focused x-ray beam 22 has its minimum cross-sectional area (e.g., the focal point of at least one x-ray optic 21), wherein the focused x-ray beam 22 has a cross-sectional area less than or equal to 1.5 times its minimum cross-sectional area. In certain embodiments, the depth of focus extends along the x-ray propagation axis 23 in a range of 1 micrometer to 500 micrometers (e.g., less than 300 micrometers; less than 200 micrometers; less than 100 micrometers).

[0026] In a particular embodiment, the object plane is within a range centered on the focal depth of the focused x-ray beam 22, and this range has a width ten times the focal depth (e.g., the range extends along the x-ray propagation axis 23 a distance ten times the focal depth). In a particular embodiment, the object plane is within a range centered on the focal depth of the focused x-ray beam 22, and this range has a width five times the focal depth (e.g., the range extends along the x-ray propagation axis 23 a distance five times the focal depth). In a particular embodiment, the object plane is within the focal depth of the focused x-ray beam 22.

[0027] In a particular embodiment, the x-ray optical system 20 may include one or more of the following:

[0028] ● Magnification, such that the size (e.g., width; diameter) of the focused x-ray spot 28 at or on sample 5 is larger than the size of the spot of the x-ray source 24 that generates x-ray 22 at that location. For example, the magnification can be greater than 1:10 (e.g., 1:7, 1:5, 1:3, 1:2) and can be achieved by the quadratic surface profile of the inner surface of the x-ray optical system 20.

[0029] ●1:1 magnification, such that the size (e.g., width; diameter) of the focused x-ray spot 28 at or on sample 5 is equal to the size of the spot of the x-ray source 24 that produces x-ray 22 at that location.

[0030] ● The reduction ratio is such that the size (e.g., width; diameter) of the focused x-ray spot 28 at or on the sample 5 is smaller than the size of the spot of the x-ray source 24 that generates the x-ray 22 at that location. For example, the reduction ratio can be less than 10:1 (e.g., 7:1, 6:1, 5:1, 4:1, 3:1, 2:1) and can be achieved by the quadratic surface profile of the inner surface of the x-ray optical system 20.

[0031] ● The maximum inner width (e.g., diameter) of the profile of the inner surface of at least one X-ray optical device 21 may be in a range of less than 10 mm (e.g., less than 6 mm; less than 4 mm; 1 mm to 4 mm; 1 mm to 2 mm; 1 mm to 3 mm).

[0032] ● The nominal outer width (e.g., diameter) of at least one X-ray optical device 21 may be in the range of 2 mm to 20 mm (e.g., 2 mm to 12 mm; 3 mm to 5 mm; 4 mm).

[0033] ● The incident / exit width (e.g., diameter) of at least one x-ray optical device 21 may be in the range of less than 4 mm (e.g., less than 2 mm; less than or equal to 1 mm).

[0034] ● The length of at least one X-ray optical device 21 may be in the range of 5 mm to 100 mm (e.g., 5 mm to 10 mm; 10 mm to 20 mm; 20 mm to 50 mm; 20 mm to 100 mm).

[0035] ● The distance between the X-ray source 24 and the sample 5 can be in the range of 50 mm to 500 mm (e.g., 50 mm to 100 mm; 100 mm to 300 mm; 150 mm to 250 mm; 100 mm to 500 mm).

[0036] ● The point spread function of the X-ray optical system 20 can be in the range of less than 15 micrometers (e.g., less than 10 micrometers; less than 5 micrometers; less than 2 micrometers; less than 1 micrometer; less than 0.7 micrometers; less than 0.5 micrometers; less than 0.3 micrometers; less than 0.2 micrometers).

[0037] ● The size (e.g., width; diameter) of the focused X-ray spot 28 at sample 5 (e.g., on sample 5) can be in a range of less than 25 micrometers (e.g., less than 15 micrometers; less than 10 micrometers; less than 5 micrometers; less than 3 micrometers; less than 2 micrometers; less than 1 micrometer; less than 0.5 micrometers; less than 0.3 micrometers).

[0038] ● At least one x-ray optical device 21 may include a central aperture (e.g., a cover) configured to attenuate (e.g., block) non-reflective x-rays propagating through at least one x-ray optical device 21 to sample 5.

[0039] In a particular embodiment, device 10 further includes an x-ray source 24 (e.g., a micro-focusing x-ray source). The x-ray source 24 may include an electron beam source configured to generate an electron beam and at least one x-ray target comprising at least one x-ray generating material (e.g., SiC, Co, Cu, Cr, W, Mo, Rh, and Au) configured to generate and emit x-rays 22 in response to bombardment of at least a portion of the electron beam onto at least one x-ray target. The generated x-rays 22 may have the energy of a characteristic x-ray line from at least one x-ray generating material, which may be in a range less than 25 keV (e.g., 4 keV to 8 keV; 5 keV to 9 keV; 5 keV to 11 keV). At least one x-ray target may be in thermal contact with a diamond substrate (e.g., in thermal communication with a thermally conductive retainer) to improve heat dissipation. For example, at least one X-ray target may include (but is not limited to) a metallic target (e.g., SiC, Co, Cu, Cr, W, Mo, Rh, and Au) comprising discrete microstructures or a target as a thin film on a diamond substrate in thermal communication with a copper holder.

[0040] In a particular embodiment, the x-ray source 24 may further include one or more of the following:

[0041] ● Multiple X-ray targets and X-ray sources 24 configured to switch between different X-ray targets to produce different X-ray spectra (e.g., X-rays with different characteristic energies).

[0042] ● A beryllium window with a reflective geometry and a thickness of less than 500 micrometers (e.g., less than 250 micrometers; less than 125 micrometers; less than 50 micrometers; less than 25 micrometers).

[0043] ● The size of the spot (e.g., width; diameter) of the X-rays 22 produced is in the range of 0.3 micrometers to 25 micrometers (FWHM) (e.g., 0.3 micrometers to 10 micrometers; 0.3 micrometers to 7 micrometers; 1 micrometer to 5 micrometers; 2 micrometers to 8 micrometers; 1 micrometer to 15 micrometers).

[0044] In a particular embodiment, microscope 30 includes a visible light microscope, an infrared microscope, and / or a near-infrared (NIR) microscope. For example, microscope 30 can be configured to operate in a bright field illumination mode and / or a dark field illumination mode.

[0045] Figure 2An exemplary objective lens 40 (e.g., an optical objective lens; a light objective lens) according to a specific embodiment described herein is schematically illustrated. Objective lens 40 includes an X-ray transmission region that extends completely through objective lens 40 (e.g., along an optical axis 41 of objective lens 40). Objective lens 40 can be manufactured by modifying a commercially available visible light objective lens (e.g., from Nikon, Olympus, Zeiss, Edmund, etc.). For example, as... Figure 2 As shown, objective 40 includes a reflective microscope objective comprising a first port 42, a second port 43, a first (e.g., primary) mirror 44, a second (e.g., secondary) mirror 46, and a stray light baffle 48. The first mirror 44 and the second mirror 46 may be aspherical or substantially spherical (e.g., based on a Schwarzschild design; with configuration to reduce aberration bias).

[0046] In a particular embodiment, the first reflector 44 and / or the second reflector 46 may include an aperture (e.g., a hole) or an X-ray transmission region configured to allow at least some X-rays 22 (e.g., via a focused X-ray beam 26) to propagate through it (e.g., having an X-ray transmission efficiency greater than 70%; greater than 25%; greater than 10%). For example, as Figure 2 As shown, the first reflector 44 includes a first aperture 45 extending through a central region of the first reflector 44 (e.g., along the optical axis 41; along the x-ray propagation axis 23), wherein a stray light baffle 48 extends through the first aperture 45, and the second reflector 46 includes a second aperture 47 extending through a central region of the second reflector 46 (e.g., along the optical axis 41; along the x-ray propagation axis 23). The first aperture 45 and the second aperture 47 can be formed by drilling or cutting the first reflector 44 or the second reflector 46, respectively. The first reflector 44 and / or the second reflector 46 may be mechanically connected to a mounting base 49 (e.g., a spider mount). The first and second apertures 45, 47 have a size (e.g., width; diameter) larger than the size (e.g., width; diameter) of the x-ray beam 22 received from the x-ray source 24.

[0047] In a particular embodiment, at least a portion of at least one x-ray optics 21 is positioned within a first aperture 45 and a stray light baffle 48. At least one x-ray optics 21 is configured to receive x-rays 22 (e.g., through a first port 42) and focus at least some of the x-rays 22 (e.g., through a first mirror 44) to form a focused x-ray beam 26 and guide the focused x-ray beam 26 (e.g., through a second mirror 46) to a sample 5 (e.g., through a second port 43). The first mirror 44 is configured to receive reflected light 34 from the sample 5 (e.g., through the second port 43) and reflect the light 34 to the second mirror 46. The second mirror 46 is configured to reflect the light 34 to other components of the microscope 30 (e.g., through the first aperture 45 and the first port 42).

[0048] In a particular embodiment, objective lens 40 may further include one or more of the following:

[0049] ● Magnification within a range of 4X to 60X (e.g., 4X; 10X; 20X; 30X; 40X; 50X; 60X).

[0050] ● A light-transmitting aperture with a width (e.g., diameter) within a range of 1 mm to 8 mm (e.g., 5.1 mm).

[0051] ● A field of view with a width (e.g., diameter) ranging from 50 micrometers to 4000 micrometers.

[0052] ● A sufficiently wide first aperture 45 or a central region of an X-ray transmission area such that at least one X-ray optic device 21 is not concentric with the optical axis 41 (e.g., not centered). In certain embodiments, most of the X-rays 22 propagating along the optical path 41 and / or the focused X-ray beam 26 are unobstructed, and a longitudinal axis of at least one X-ray optic device 21 may be tilted from the optical axis 41 by an angle of less than 10 degrees (e.g., within a range of 5 to 10 degrees (as a non-limiting example)).

[0053] In certain other embodiments, objective 40 includes a refractive microscope objective comprising at least one lens. The at least one lens may have an aperture (e.g., a hole) configured to receive at least one x-ray optics 21 and allow at least some x-rays 22 to propagate through it (e.g., having an x-ray transmission efficiency greater than 70%; greater than 25%; greater than 10%).

[0054] In a specific implementation, such as Figure 1As shown, the device 10 further includes a reflector 50, at least one light source 60 (e.g., a light-emitting diode; an optical fiber), and at least one photodetector 70 (e.g., a camera; a Goldeye short-wave infrared camera from Allied Vision, Stadtroda, Germany). Figure 1 As shown, at least one light source 60 may include a dark-field light port 62, a bright-field light port 64, and an optical element string 66 configured to provide optical communication between the microscope 30 and the dark-field light port 62, the bright-field light port 64, and at least one photodetector 70. At least one light source 60 may be configured to illuminate a portion of the sample 5 with light 69 (e.g., visible light; infrared light; near-infrared light), and the objective lens 40 may be configured to receive a reflected portion of light 34 from that portion of the sample 5 and guide the reflected portion of light 34 to the optical element string 66, which provides light 34 to at least one photodetector 70. Examples of optical element strings 66 compatible with the specific embodiments described herein include (but are not limited to) the Wide Video Microscope Unit (VMU) series available from Mitutoyo in Takatsu-ku, Kawasaki, Kanagawa Prefecture, Japan. In a particular embodiment, the optical element string 66 may be considered to further include the objective lens 40. Although a portion of the sample 5 is illuminated by light propagating through the optical element string 66 and through the objective lens 40 in a particular embodiment, in certain other embodiments, ring illumination or fiber optic illumination separate from the objective lens 40 may be used.

[0055] In a particular embodiment, mirror 50 is configured to receive and reflect a portion of light 34 from sample 5, the light 34 propagating substantially collinearly with the focused x-ray beam 26 (e.g., along the x-ray propagation axis 23). Mirror 50 is positioned and configured along both the optical axis 41 and the x-ray propagation axis 23 of objective lens 40 to receive light 34 from objective lens 40 and to reflect light 34 away from the x-ray propagation axis 23 (e.g., greater than 30 degrees, greater than 60 degrees, or greater than 90 degrees) toward at least one photodetector 70. For example, mirror 50 may be positioned such that the reflecting surface is at a 45-degree angle relative to the x-ray propagation axis 23, causing light 34 to deflect by 90 degrees. Figure 3An exemplary microscope 30, including a mirror 50, is schematically illustrated according to a specific embodiment described herein. The mirror 50 includes an aperture 52 (e.g., a hole) or an X-ray transmission region that extends completely through the mirror 50 along the X-ray propagation axis 23 and is configured to allow at least some X-rays 22 to propagate through it (e.g., having an X-ray transmission efficiency greater than 70%; greater than 25%; greater than 10%). In certain other embodiments, the mirror 50 includes a material of sufficient thickness and sufficient to transmit X-rays 22 to allow greater than 10% (e.g., greater than 25%; greater than 70%) of the X-rays 22 to propagate through the mirror 50. Figure 3 It also shows a region 29 that overlaps with and / or is adjacent to the focused X-ray spot 28, from which light 34 reflected from the sample 5 is blocked (e.g. by the second mirror 46 or other components of the objective lens 40) so that it does not reach the first mirror 44 (e.g., so that the light 34 reflected from this blocked region 29 is not guided by the objective lens 40 and the mirror 50 to at least one photodetector 70).

[0056] although Figure 3 The reflected light 34 is guided by the objective lens 40 and the reflector 50 toward at least one photodetector 70, but in a certain embodiment, the objective lens 40 and the reflector 50 also guide incident light from at least one light source 60 to the sample 5. Figure 4 A schematic illustration of an exemplary microscope 30 configured for dark-field correlation (e.g., non-X-ray) imaging according to a specific embodiment described herein. The microscope 30 includes a dark-field illumination port 62 of at least one light source 60 (e.g., configured to receive light 69 from a ring illuminator or a fiber optic illuminator), a condenser 82, a condenser-aperture stop 84 having a central aperture 85, a mirror 50 having a central aperture 52, an objective-aperture stop 86, and an objective lens 40 (in... Figure 4 (indicated by a main plane) and a condenser 88 (e.g., annular condenser). Figure 4 The microscope 30 can be configured to generate a ring-shaped (e.g., annular) beam 89 (e.g., focused by a condenser 88) and irradiate the sample 5 with the annular beam 89. Dark-field information can travel through the center of the aperture 52 to be detected.

[0057] Figure 5A portion of an optical element string 66 (e.g., VMU) according to a specific embodiment described herein is schematically illustrated. The optical element string 66 includes a reflected light dark-field mirror block 90 (e.g., a right-angle mirror) compatible with performing dark-field correlation (e.g., non-X-ray) microscopy. The mirror block 90 includes an elliptical front surface mirror 92 and a spider-shaped aperture 94. Light 69 from at least one light source 60 (e.g., dark-field illumination port 62) is received by the mirror block 90 and guided through the objective lens 40 to the sample 5.

[0058] In a particular embodiment, device 10 is configured to guide and probe a sample 5, including a semiconductor device under test. In a particular embodiment, microscope 30 is used for guiding the sample 5, and x-ray optics system 20 is used for circuit design debugging and / or determining locations of marginal failures. In a particular embodiment where sample 5 includes a semiconductor wafer, a focused x-ray beam 26 and non-x-ray light 69 illuminate the same sides of sample 5, while in certain other embodiments, the focused x-ray beam 26 and non-x-ray light 69 illuminate different sides of sample 5. In a particular embodiment, the focal point of the focused x-ray beam 26 can be aligned with the light 69 illuminating sample 5, and microscope 30 can be retracted to provide space for a large solid-angle x-ray detector. In a particular embodiment, x-ray optics system 20 includes a recess (e.g., a groove) on the side of at least one x-ray optics element 21 to allow for closer placement of at least one solid-state detector (SSD).

[0059] Figure 6 Another exemplary device 10 according to a specific embodiment described herein is schematically illustrated. Device 10 includes an x-ray optical system 20 comprising at least one x-ray optics element 21 and a microscope 30 including an objective lens 40. The at least one x-ray optics element 21 and the objective lens 40 are aligned to the same position at a sample 5. The at least one x-ray optics element 21 may include a capillary wherein at least a portion of its internal reflective surface profile has the shape of at least one segment of a quadratic surface shape (such as an ellipsoid, hyperboloid, paraboloid, or sphere), as described herein. Figure 6As shown, at least one x-ray optics 21 and objective lens 40 are co-registered with each other (e.g., the light 34 received by objective lens 40 comes from the same sample 5 as the light spot irradiated by the focused x-ray beam 26) but are not axially aligned with each other (e.g., the x-ray propagation axis 23 of at least one x-ray optics 21 is not collinear with the optical axis 41 of objective lens 40). For example, objective lens 40 may have a recess (e.g., a groove; a channel) and at least one x-ray optics 21 may be positioned in the recess. In certain embodiments, objective lens 40 and at least one x-ray optics 21 are integral with each other (e.g., a single unit), while in certain other embodiments, at least one x-ray optics 21 is spaced apart from objective lens 40. The angle between x-ray propagation axis 23 and optical axis 41 is in the range of 30 degrees to 60 degrees (e.g., 45 degrees).

[0060] Figure 6 Also shown is the portion 90 of reflected light 34 blocked from region 29 of sample 5, which may be present where at least one x-ray optics 21 is at least partially within objective lens 40 (e.g., see [reference]). Figures 1 to 3 A specific embodiment of the ) and at least one of the x-ray optical elements 21 is located outside the objective lens 40 (e.g., see Figure 6 In certain embodiments, at least one x-ray optics 21 may be tilted relative to the objective lens 40 (e.g., the x-ray propagation axis 23 may have a non-zero angle relative to the optical axis 41). In certain other embodiments, at least one x-ray optics 21 may be substantially parallel to the optical axis 41 and displaced from the optical axis 41 (e.g., at least one x-ray optics 21 displaced from a central axis of the objective lens 40). Figure 7A An exemplary device 10 is schematically illustrated, in which at least one x-ray optics 21 according to a particular embodiment described herein is tilted relative to an objective lens 40. The non-zero angle between the x-ray propagation axis 23 and the optical axis 41 may be in the range of less than 45 degrees (e.g., 5 to 10 degrees) or less than 5 degrees. Figure 7B Schematic illustration of the correspondence to a specific implementation described herein Figure 7A A top view of sample 5 with focused X-ray beam 28 and reflected light 34. Figure 7B A focused X-ray spot 28 is shown that overlaps with the area illuminated by incident light 69, from which reflected light 34 is received by objective lens 40 (e.g., objective lens 40 does not receive reflected light 34 from the blocked area 29). Although the illumination contrast can be reduced by blocking some of the reflected light 34 by at least one X-ray optics 21, the size (e.g., width; diameter) of the focused X-ray spot 28 can be negligibly affected by making at least one X-ray optics 21 not perpendicular to the surface of sample 5.

[0061] Although common terms are used to describe systems and methods of particular embodiments for ease of understanding, these terms are used herein to have the broadest reasonable interpretation. While various aspects of the invention are described with respect to illustrative examples and embodiments, the disclosed examples and embodiments should not be construed as limiting. Unless otherwise specifically stated or understood in the text, conditional terms such as “can,” “may,” “may,” or “may” are generally intended to convey that a particular embodiment includes a particular feature, element, and / or step that is not included in other embodiments. Therefore, such conditional terms are generally not intended to imply that a feature, element, and / or step is necessary in any way for one or more embodiments. Specifically, the terms “comprises” and “comprising” should be interpreted as referring to an element, component, or step in a non-exclusive manner, indicating that the referenced element, component, or step may be present or utilized or combined with other elements, components, or steps not explicitly referenced.

[0062] Unless otherwise specifically stated, connective phrases such as “at least one of X, Y, and Z” should generally be understood within the context to convey that an item, term, etc., can be X, Y, or Z. Therefore, this connective phrase is generally not intended to imply that a particular implementation requires the presence of at least one of X, at least one of Y, and at least one of Z.

[0063] As used herein, terms of degree (such as “approximately,” “about,” “substantially,” and “substantially”) refer to a value, quantity, or characteristic that still performs a desired function or achieves a desired result close to the stated value, quantity, or characteristic. For example, the terms “approximately,” “about,” “substantially,” and “substantially” may refer to a quantity within ±10%, ±5%, ±2%, ±1%, or ±0.1% of the stated quantity. As another example, the terms “substantially parallel” and “substantially parallel” refer to a value, quantity, or characteristic that deviates from exact parallelism by ±10 degrees, ±5 degrees, ±2 degrees, ±1 degree, or ±0.1 degrees, and the terms “substantially perpendicular” and “substantially perpendicular” refer to a value, quantity, or characteristic that deviates from exact perpendicularity by ±10 degrees, ±5 degrees, ±2 degrees, ±1 degree, or ±0.1 degrees. The scope disclosed herein also covers any and all combinations of overlapping, sub-scopes, and the like. Terms such as “up to,” “at least,” “greater than,” “less than,” “between,” and the like include the cited numbers. As used herein, unless otherwise expressly indicated in the text, the meanings of “a,” “an,” and “the” include plural references. Although the structure and / or method are discussed in this document based on elements marked by ordinal adjectives (e.g., first, second, etc.), ordinal adjectives are used only as markers to distinguish elements from one another, and are not used to indicate an order in which such elements or such elements are used.

[0064] Various configurations have been described above. It should be understood that the embodiments disclosed herein are not mutually exclusive and can be combined with each other in various configurations. Although the invention has been described with reference to these specific configurations, the description is intended to illustrate the invention and not to be limiting. Various modifications and applications will be apparent to those skilled in the art without departing from the true spirit and scope of the invention. Therefore, for example, in any method or procedure disclosed herein, the actions or operations constituting the method / procedure can be performed in any suitable sequence and are not necessarily limited to any particular disclosed sequence. Features or elements from the various embodiments and examples discussed above can be combined with each other to produce alternative configurations compatible with the embodiments disclosed herein. Various aspects and advantages of the embodiments have been described as appropriate. It should be understood that not all such aspects or advantages are achieved according to any particular embodiment. Therefore, for example, it should be recognized that various embodiments can be implemented in a way that achieves or optimizes one advantage or group of advantages taught herein without necessarily achieving other aspects or advantages that may be taught or implied herein.

Claims

1. An apparatus, the apparatus comprising: An X-ray optical system configured to receive X-rays from an X-ray source, to focus at least some of the X-rays to form a focused X-ray beam, and to irradiate a portion of a sample with the focused X-ray beam, the focused X-ray beam having a depth of focus and a focused X-ray spot at the sample. and A microscope comprising an objective lens configured to receive and focus light from said portion of said sample, the objective lens having an object plane and a field of view, the object plane being within a range centered on the depth of focus of said focused X-ray beam, the range having a width ten times the depth of focus, and the focused X-ray spot being within the field of view of said objective lens.

2. The apparatus of claim 1, wherein at least a portion of the x-ray optical system is positioned within the objective lens.

3. The apparatus of claim 1, further comprising a light source configured to illuminate the portion of the sample with incident light, the objective lens configured to receive a reflected portion of the incident light from the portion of the sample.

4. The device of claim 3, wherein the light source comprises both bright field and dark field illumination.

5. The device of claim 4, wherein the dark field illumination comprises a ring illuminator or a fiber optic illuminator.

6. The apparatus of claim 1, further comprising the x-ray source, the x-ray source comprising: An electron beam source, which is configured to generate an electron beam; and At least one target, the at least one target comprising at least one x-ray generating material, the at least one x-ray generating material being configured to generate and emit x-rays in response to bombardment by at least a portion of the electron beam.

7. The apparatus of claim 1, wherein the x-ray optical system comprises at least one capillary x-ray optical element having an inner surface profile comprising at least one segment of a quadratic surface shape.

8. The apparatus of claim 1, wherein the angle between the propagation direction of the focused X-ray beam and the optical axis of the objective lens is less than 30 degrees.

9. The apparatus of claim 1, wherein the microscope further comprises a reflector configured to receive and reflect light from the portion of the sample that is substantially collinear with the x-ray propagation axis and deflect at least some of the light away from the x-ray propagation axis.

10. The device of claim 1, wherein the device comprises a multimode lighting device.

11. The apparatus of claim 1, wherein the microscope is a visible light microscope, an infrared microscope, and / or a near-infrared microscope.

12. The apparatus of claim 1, wherein the microscope is configured to operate in a bright field illumination mode and / or a dark field illumination mode.

13. The apparatus of claim 1, wherein the objective lens comprises a reflective microscope objective lens.

14. The apparatus of claim 13, wherein the reflective microscope objective comprises a first aspherical mirror and a second aspherical mirror.

15. The apparatus of claim 1, wherein the objective lens comprises a refractive microscope objective lens.

16. The apparatus of claim 15, wherein the refractive microscope objective comprises at least one lens.

17. The apparatus of claim 1, wherein the objective lens includes an aperture, and at least a portion of the x-ray optical system is located within the aperture.

18. An apparatus, the apparatus comprising: An X-ray optical system configured to receive X-rays from an X-ray source, to focus at least some of the X-rays to form a focused X-ray beam, and to irradiate a portion of a sample with the focused X-ray beam, the focused X-ray beam having a depth of focus and a focused X-ray spot at the sample. and A microscope objective lens configured to receive and focus light from said portion of said sample, said objective lens having an optical axis and said x-ray optical system having an x-ray propagation axis tilted relative to said optical axis, said objective lens having an object plane and a field of view, said object plane being within a range centered on said depth of focal length of said focused x-ray beam, said range having a width ten times said depth of focal length, and said focused x-ray spot being within said field of view of said objective lens.

19. The apparatus of claim 18, wherein the x-ray optical system is positioned outside the objective lens.

20. The apparatus of claim 18, wherein at least a portion of the x-ray optical system is positioned within the objective lens.

21. The apparatus of claim 18, wherein the x-ray propagation axis and the optical axis have a non-zero angle between them.

22. The device of claim 21, wherein the non-zero angle is in the range of 5 degrees to 30 degrees.

23. The device of claim 21, wherein the non-zero angle is in the range of less than 5 degrees.

24. An apparatus, the apparatus comprising: At least one x-ray optics device, the at least one x-ray optics device being configured to receive x-rays from an x-ray source to focus at least some of the x-rays to form a focused x-ray beam and to irradiate a portion of a sample with the focused x-ray beam, the focused x-ray beam having a depth of focus and a focused x-ray spot at the sample; and An objective lens configured to receive and focus light from said portion of said sample, said objective lens having an optical axis and said at least one X-ray optic having an X-ray propagation axis substantially parallel to and displaced from said optical axis, said objective lens having an object plane and a field of view, said object plane being within a range centered on said depth of focus of said focused X-ray beam, said range having a width ten times said depth of focus, and said focused X-ray spot being within said field of view of said objective lens.

25. The apparatus of claim 24, wherein the at least one X-ray optics is displaced from the central axis of the objective lens.

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