X-ray focusing and wavelength selection

Abstract

The X-ray optical system includes (i) an achromatic collimating optical system that collimates an input X-ray beam to provide a collimated X-ray beam, and (ii) an adjustable diffraction unit, the adjustable diffraction unit being configured to receive the collimated X-ray beam when (a) configured according to a current configuration associated with a current wavelength selected from a variety of wavelengths, and (b) configured to filter the collimated X-ray beam to provide a filtered collimated X-ray beam of the current wavelength, and the achromatic focusing optical system being configured to focus the filtered collimated X-ray beam to provide a focused filtered X-ray beam.

Description

Technical Field

[0001] (Cross-reference) This application claims priority from U.S. Provisional Patent Application No. 63 / 492,246, filed Mar. 26, 2023, which is incorporated herein by reference.

[0002] This application relates to X-ray focusing and wavelength selection.

[0003] X-ray measurements in a semiconductor measurement environment generally require an X-ray delivery and focusing system with a small footprint. The Fab space is expensive, and many high-brightness X-ray sources, such as those employed at national laboratories using synchrotron radiation (SR) or free electron lasers (FELs), are not only prohibitively expensive to operate but are also too large for use in measurement and inspection.

[0004] Other scalable high-brightness X-ray sources include electron beam-induced gas or solid plasma sources, electron beam-generated X-rays from solid targets (bremsstrahlung fluorescence), and electron beam / liquid metal jet sources. Typical measurement applications include X-ray scattering (XRS), X-ray diffraction (XRD), small-angle X-ray scattering (SAXS), X-ray fluorescence (XRF), total reflection X-ray fluorescence (TXRF), and X-ray photoelectron spectroscopy. Each of these applications requires a different excitation X-ray energy (wavelength) range, and therefore requires not only differences in X-ray energy bandwidth but also different focusing or collimation systems.

[0005] These systems are not flexible.

[0006] There is a growing need to provide more flexible systems.

[0007] The subject matter of this invention is specifically identified and explicitly claimed in the concluding section of the specification. However, this invention, along with its purpose, features and advantages, as well as its mechanism and method of operation, will be best understood by referring to the following detailed description, along with the accompanying drawings. [Brief explanation of the drawing]

[0008] [Figure 1] An example of an X-ray optical system is shown. [Figure 2] An example of an X-ray optical system is shown. [Figure 3] An example of an X-ray optical system is shown. [Figure 4] An example of an X-ray optical system is shown. [Figure 5]An example of an X-ray optical system is shown. [Figure 6] An example of an X-ray optical system is shown. [Figure 7] An example of an X-ray optical system is shown. [Figure 8] Examples of Bragg angle pair X-ray wavelengths for several selected monochromator / diffraction crystals between 0.6 and 20 A, and examples of Bragg angle pair X-ray wavelengths for several selected monochromator / diffraction crystals between 20 and 120 A are shown. [Figure 9] An example of an X-ray optical system is shown. [Figure 10] An example of an X-ray optical system is shown. [Figure 11] Here is an example of the method. [Figure 12] Here is an example of the method. [Figure 13] This example shows how to focus an X-ray beam from a finite X-ray source through an ellipsoidal monochromator or a toroidal monochromator. [Figure 14] This shows an example of the reflectivity of a fixed-angle multilayer substrate in the energy range of 100-1000 eV, where other incident X-rays are strongly suppressed. [Figure 15] This example shows X-ray focusing via a Schwarzschild objective lens using a multilayer coating for low-energy X-rays. [Figure 16] An example of a multilayer zone plate with an interface inclined to satisfy the Bragg angle is shown. [Figure 17] An example of X-ray transport via a polycapillary lens is shown. [Figure 18] An example of X-ray transport via a reflective (Type I Walters) optical system is shown. [Modes for carrying out the invention]

[0009] Typical examples include flexible, compact X-ray focusing systems for XPS / XRF measurement applications using various X-ray energies and energy bandwidths, without prejudice, their expandability to other measurement applications. In particular, methods for focusing multiple, selectable energy monochromatic X-ray beams onto a wafer surface are described. Flexible operation methods for this system are also provided.

[0010] The flexible X-ray focusing system provided incorporates a dedicated X-ray optical system that is not optimized for just a single and specific X-ray energy. This system offers high performance and flexibility, in contrast to the prior art dedicated monochromatic X-ray focusing systems, which lack flexibility and are costly to achieve. The prior art systems become prohibitively expensive when a wide range of X-ray energies are beneficial to the application, i.e., when using two or more monochromatic focusing systems for two or more X-ray energies, making the above system more cost-effective than the prior art systems. We will describe a method that allows an X-ray beam transport system to focus a number of selectable monochromatic X-ray energies (wavelengths) through the measurement site. X-ray targets from gaseous, solid, or liquid metal jet high-brightness X-ray sources not only generate characteristic X-ray lines from the target but also vary the intensity of continuum radiation, known as Bremsstrahlung.

[0011] In particular, if a compact X-ray focusing system can provide a continuously or semi-continuously adjustable monochromatic X-ray beam that can be focused onto the measurement site, high-intensity continuous radiation can be used as an excitation source for specific applications. The X-ray focusing system features discretely selectable X-ray energy. The X-ray focusing system consists of fixed focusing elements combined with, but is not limited to, a monochromator crystal or multilayer.

[0012] A typical example is a given Bragg angle θ b This method involves using an achromatic point-to-parallel optics system to direct an X-ray source (a) from a flat monochromator crystal or multilayer film. A second reversed point-parallel optic is positioned at the exit angle of the monochromator crystal to focus the X-ray beam onto the measurement site.

[0013] In one embodiment, an X-ray optical system is provided that includes the following: a. Achromatic collimating optics that collimate (parallelize) the input (incident) X-ray beam to provide a collimated X-ray beam. b. (a) A current configuration selected from various configurations associated with different wavelengths, which receives the collimated X-ray beam while configured according to the current configuration associated with the current wavelength selected from various wavelengths, and (b) filters the collimated X-ray beam to provide a filtered collimated X-ray beam of the current wavelength. c. An achromatic focusing optics configured to collect a filtering collimated X-ray beam to provide a collected filtering X-ray beam.

[0014] In one embodiment, the adjustable diffraction unit includes different diffraction elements that are associated with different wavelengths.

[0015] In one embodiment, the current configuration includes positioning (arranging) one of the adjustable diffraction elements within the path of the collimated X-ray beam (while on the other hand, the other adjustable diffraction elements are arranged outside the path).

[0016] In one embodiment, the positioning includes at least one of the following. a. Moving at least some of the different diffraction elements. b. Moving other elements of the X-ray optics (such as an achromatic collimating optics and / or an achromatic focusing optics) associated with at least some of the different diffraction elements. c. Moving the position of the input X-ray beam using mechanical means and / or optical means.

[0017] In one embodiment, the movement is performed linearly, non-linearly, rotationally, etc. along one axis or multiple axes.

[0018] In one embodiment, the diffraction element is a grating, a multilayer diffractor, or other diffraction element.

[0019] In one embodiment, the different diffraction elements are associated with different wavelengths.

[0020] In one embodiment, different diffraction elements exhibit different lattice spacings.

[0021] In one embodiment, various diffracting elements exhibit different compositions.

[0022] In one embodiment, the diffraction element is a variety of different plane gratings associated with different wavelengths.

[0023] In one embodiment, various diffraction elements are arranged in an array or in no particular order. The array may be a linear array, a multidimensional array, a radially symmetrical array, or another nonlinear array.

[0024] In one embodiment, various diffraction elements are arranged in a linear array, and the above-mentioned unit is configured to move one of the various diffraction elements into the path of the collimated X-ray beam.

[0025] In one embodiment, various diffraction elements are connected to a turret, and the above-mentioned unit is configured to move one of the various diffraction elements into the path of the collimated X-ray beam.

[0026] In one embodiment, the system includes various ellipsoid monochromators, each with different diffraction elements associated with different wavelengths.

[0027] In one embodiment, various diffraction elements further comprise demagnifying optics.

[0028] In one embodiment, the X-ray optical system includes a component unit for selecting one of several diffraction elements that interact with the collimated X-ray beam. This component unit may be a controller.

[0029] In one embodiment, the adjustable diffraction unit includes a diffraction element and a component unit configured to determine the Bragg condition of the diffraction element.

[0030] In one embodiment, the above-described unit is configured to set the optical axis of the collimated X-ray beam, the optical axis of the filtering-collimated X-ray beam, and the distance between the diffraction element and at least one of the collimating optical system or the focusing optical system.

[0031] In one embodiment, the above-described unit is configured to set the optical axis of the collimated X-ray beam by rotating the collimating optical system while maintaining a constant source-to-focus distance, and to set the optical axis of the filtered-collimated X-ray beam by rotating the focusing optical system.

[0032] In one embodiment, the adjustable diffraction unit includes various diffraction elements associated with various wavelengths, the different diffraction elements include the diffraction element, and the configuration unit is further configured to select one of the diffraction elements to interact with the collimated X-ray beam.

[0033] Figures 1 and 2 show multiple diffraction elements, such as crystal diffractors 31(1)-31(8), which have the same Bragg condition. They are arranged in a line and movable manner along a first axis 32, and one of the crystal diffractors is selected at a predetermined timing. In Figure 1, the first crystal diffractor 31(1) is selected, and in Figure 2, the third crystal diffractor 31(3) is selected.

[0034] In both Figure 1 and Figure 2, an X-ray source (a source) 20, an initial spot 21 formed on the X-ray source, and input X-rays 22 are shown, and the input X-rays are collimated by an achromatic collimating optical system 23 configured to collimate the input X-ray beam to provide a collimated X-ray beam 24.

[0035] The collimated X-ray beam 24 collides with a selected crystal diffractor (associated with the current wavelength), and the selected crystal diffractor filters the collimated X-ray beam to provide a filtered collimated X-ray beam 25 that exhibits the current wavelength.

[0036] The achromatic focusing optical system 26 is configured to focus the filtering and collimated X-ray beam 25 to provide a focused filtered X-ray beam 27, which collides with the target 29 to form a spot 28 on the target. The target may be a sample or a part of a sample.

[0037] Figure 3 shows several examples of moving various (different) quartz diffraction elements 31(1) to 31(8), including those using linear motion along one axis (see dashed arrow 32), linear motion along two axes (see dashed arrow 32-1), rotational motion (see dashed arrow 32-2), and those using various holders 33 to provide mechanical coupling between various quartz diffraction elements and moving elements (rotating motor 36, linear motor 34, or two-axis motion unit 35). In one embodiment, the above movement is controlled by a controller 60 which may include one or more parts of one or more integrated circuits.

[0038] As an example, assuming a Bragg angle of 60 degrees, the X-ray optical systems shown in Figures 1 and 2 can be applied to the following X-ray energies by using a monochromator crystal with selectable fixed height and angle, as shown in Table 1 below.

[0039] [Table 1]

[0040] Table 1 shows the approximate transmitted and focused X-ray energies for various monochromator crystals and multilayer films, using an achromatic input / output optical system with a fixed Bragg angle of 60 degrees.

[0041] Multilayer diffractors can be optimized for various X-ray energies by utilizing different material combinations, layer ratios and thicknesses, and the number of layers on the substrate. This applies to WSi and CrTi multilayer films.

[0042] Figures 1 and 2 show an example in which X-rays are transported from an X-ray source to a monochromator via point-to-parallel optics, and the resulting monochromatic discretely selectable X-ray beam is focused onto the measurement site.

[0043] Figure 4 shows a diagram of six crystal diffractometers or multilayer diffractometers 31(1)-31(6) mounted on an axially rotatable turret 37. Figure 4 also shows the X-ray source 20, initial spot 21, input X-rays 22, achromatic collimating optics 23, collimated X-ray beam 24, filtering collimated X-ray beam 25, achromatic focusing optics 26, focused filtering X-ray beam 27, target 29, and spot 28.

[0044] Figure 5 shows an X-ray optical system, which differs from the X-ray optical system in Figure 1 in that the crystal diffraction element remains stationary, while other parts of the X-ray optical system, such as the achromatic collimating optical system 23 (moved using the collimating optical system operating unit 42) and the achromatic focusing optical system 26 (moved using the focusing optical system operating unit 43), and / or the X-ray source (position of spot 22), are moved using the X-ray source operating unit 41. Linear movement is indicated by the dashed arrow 32.

[0045] In one embodiment, a more flexible method to enable quasi-continuous X-ray focusing is achieved by changing a combined tilt of the input and output optical systems (for example, including an achromatic collimating optical system 23 and an achromatic focusing optical system 26, respectively).

[0046] Figures 6 and 7 show the diffracting element 31-1 at two different positions (height or distance from the target), where the two different positions correspond to various Bragg angles and tilt angles of the achromatic collimating optical system 23 and the achromatic focusing optical system 26 (see curved arrows 32-2 indicating rotational motion). The collimating optical system rotation unit 45 rotates the achromatic collimating optical system 23. The focusing optical system rotation unit 46 rotates the achromatic focusing optical system 26.

[0047] Since changes in the Bragg angle (indicated by symbols 51 and 52) also change the outgoing monochromatic X-ray beam directed towards the final focusing optics, it is necessary to simultaneously change the distance of the crystal-to-input and final focusing optics.

[0048] To achieve a shallower Bragg angle, i.e., higher energy X-ray transport, it is necessary to reduce the emission point-to-diffractor crystal, bring the diffraction stage system closer to the incident parallel X-ray beam, and reverse the angle correction of the focusing optical system (opposite sign or source focusing optical system) to keep the fixed X-ray spot stationary at the measurement site.

[0049] The X-ray optical systems shown in Figures 6 and 7 can be used for a fixed source-to-metrology distance. In particular, the X-ray transport from the X-ray source to the target (measurement site) and the semi-continuous X-ray energy transport are highly flexible and can provide a solution to a continuous range of semi-continuous wavelengths.

[0050] Graph 71 in Figure 8 shows the Bragg angle and the X-ray wavelengths of monochromators / diffraction crystals selected in the range of 0.6 to 20 Å.

[0051] Graph 72 in Figure 9 shows the Bragg angle and the X-ray wavelengths of selected monochromatic / diffraction crystals in the range of 20–120 Å. This figure shows the applicable X-ray wavelength ranges for several representative monochromatic / diffraction crystals.

[0052] The focusing input / output optical system may include a nested Wolters optics, including a central poly-capillary optics. The input and output optical systems may have different focal lengths.

[0053] The more flexible method described above can be extended by using a set of several monochromator crystals mounted on a turret or linear translator that can be moved toward the incident X-ray beam path.

[0054] The proposed solution provides a compact, stepwise energy-selectable X-ray focusing system for semiconductor measurement. This system is capable of transporting and focusing monochromatic X-ray beams and is extendable to X-rays ranging from several hundred eV to several keV.

[0055] The system described above is a compact quasi-continuous X-ray energy focusing system for guiding and focusing a monochromatic X-ray beam to the measurement site. This system is capable of transporting and focusing monochromatic X-ray beams ranging from several hundred eV to several keV.

[0056] The above-mentioned solution can be represented by at least one of the following: a. X-ray transport through an optical system configuration that monochromatically focuses a polychromatic or partially monochromatic X-ray source beam with a diameter of less than 100 μm at the analysis site. A system that collects bX-rays, monochromatizes the X-ray beam, and then focuses it onto the area to be analyzed. c. Providing X-ray focusing of a monochromatic X-beam with stepwise selectable energy that is focused onto the measurement site. A continuously energy-adjustable X-ray focusing system over a limited energy range of dX-rays.

[0057] Figures 9 and 10 show examples of X-ray optical systems, including the following: a. A focusing monochromator 110 is configured to (i) receive a noncollimated input X-ray beam 109 such that the noncollimated input X-ray beam forms a first spot 103 on a target on a first surface 108, and (ii) filter and focus the noncollimated X-ray beam to provide a filtered focused X-ray beam 116 of the current wavelength. In one embodiment, the focusing monochromator 110 is an elliptical monochromator or a toroidal monochromator. b. A demagnifying achromatic optical system 117 configured to demagnify the filtered focused X-ray beam of a current wavelength to form a target spot 119 smaller than the first spot 103 on the sample surface 120. The demagnifying achromatic optical system 117 further outputs another non-collimated X-ray beam 119.

[0058] In one embodiment, the first spot is imaged onto a second surface 115 located between the focusing monochromator 110 and the attenuating achromatic optical system 117. The first surface 108 and the second surface 115 are conjugate planes.

[0059] In Figure 9, the X-ray optical system also includes imaging achromatic optics 105 that receive the input X-ray beam 104. The X-ray beam 104 is generated by irradiating the target with a laser beam 102 (generated by the laser source 101), forming a spot 103 on the target. The imaging achromatic optics 105 outputs another non-collimated X-ray beam 106 that forms a spot 107 on the first surface 108.

[0060] In Figure 10, the X-ray beam source (for example, the target to which the laser beam 102 generated by the laser source 101 is irradiated) is positioned on the first surface.

[0061] In one embodiment, either the X-ray optical system in Figure 9 or Figure 10 can be used as part of an adjustable X-ray optical system.

[0062] In one embodiment, an X-ray optical system is provided that includes various focusing monochromators associated with different wavelengths, corresponding to various wavelengths.

[0063] Demagnification

[0064] In one embodiment, the collection efficiency as well as the final spot size of an X-ray focusing system for a specific single X-ray energy is controlled or improved by using a focusing optical system that images the X-ray source emission spot to the focus of an ellipsoidal or toroidal monochromator for the specific X-ray energy.

[0065] The monochromatic X-ray focus of the monochromator is imaged onto the wafer surface. Alternatively, a second optical system positioned at the conjugate image position of the monochromator images the monochromatic X-ray beam spot onto the wafer and then image / demagnify it.

[0066] An elliptic or toroidal monochromator with an X-ray source conjugate, positioned in the emission region of the X-ray source, generates a monochromatic focus at the image conjugate point / distance for a given X-ray energy.

[0067] A focusing optical system positioned at the image spot of a monochromator can be used to demagnify the monochromatic image on a wafer to a spot size smaller than the spot generated at the focus of the monochromator.

[0068] The imaging optics can be either achromatic reflective or polycapillary optics.

[0069] In one embodiment, an X-ray optical system is provided that includes an X-ray acquisition system, which focuses a polychromatic source at the source conjugate of a focusing monochromator (either ellipsoidal or toroidal in shape) and demagnifies the image conjugate of the monochromator via fully focusing optics onto the wafer or mask measurement area. The final focal point on the target (e.g., on the wafer) is smaller than the spot size achievable using the monochromator alone (see, for example, Figures 9 and 10).

[0070] In one embodiment, source imaging optics are used to optimize the X-ray collection efficiency from the X-ray source to the (focusing) monochromator source conjugate, thereby minimizing / optimizing the size and shape of the monochromator for a low-luminance X-ray source.

[0071] In one embodiment, the X-ray optical system is simplified by placing a demagnifying achromatic X-ray optical system (reflective or polycapillary) at the image conjugate of a fixed magnification monochromator, thereby providing a selectable demagnification for an ellipsoidal or toroidal monochromator. As a result, the final X-ray spot size at the wafer metrology site can thus be monochromatic and smaller than the size achievable with a focusing monochromator alone.

[0072] In one embodiment, the proposed demagnification is applied to the optical system shown in Figure 13 or other X-ray optical systems.

[0073] Figure 11 shows an example of method 200 for manipulating the input X-rays.

[0074] In one embodiment, method 200 includes step 210, which collimates the input X-ray beam using an achromatic collimating optical system to provide a collimated X-ray beam.

[0075] In one embodiment, step 210 is followed by step 220, in which the collimated X-ray beam is received when it is configured according to the current configuration associated with the current wavelength (corresponding to the current wavelength selected from among the various wavelengths) by an adjustable diffraction unit.

[0076] In one embodiment, step 220 is followed by step 230, in which the collimated X-ray beam is filtered by an adjustable diffraction unit to provide a filtered collimated X-ray beam of the current wavelength.

[0077] In one embodiment, step 230 is followed by step 240, in which the filtered and collimated X-ray beam is focused by an achromatic focusing optical system to provide a focused filtered X-ray beam.

[0078] In one embodiment, method 200 is performed using one of the X-ray optical systems shown in any of Figures 1 to 7.

[0079] In one embodiment, method 200 includes selecting a current configuration and / or receiving a request or instruction to apply the current configuration, and configuring the adjustable diffraction unit to the current configuration 205.

[0080] The current configuration may change over time.

[0081] Examples of the above configuration include the following: a. Moving at least some of the various diffraction elements. b. Moving other elements of the X-ray optical system (such as an achromatic collimated optical system and / or an achromatic collimated optical system) with respect to at least some of the various diffracting elements. c. Moving the position of the input X-ray beam using mechanical and / or optical means. d. Moving adjustable diffraction elements and / or changing the tile angle of various optical systems.

[0082] Figure 12 shows an example of method 300 for manipulating X-rays.

[0083] In one embodiment, method 300 includes method 310, in which a non-collimated input X-ray beam is received by a focusing monochromator, and the non-collimated input X-ray beam forms a first spot in a first virtual plane.

[0084] In one embodiment, step 310 is followed by step 320, in which the non-collimated X-ray beam is filtered and focused by the focusing monochromator to provide a filtered and focused X-ray beam of the current wavelength.

[0085] In one embodiment, step 330 is followed by step 340, in which the filtered focused X-ray beam of the current wavelength is demagnified by demagnifying achromatic optics to form a target spot smaller than the first spot on the sample surface.

[0086] In one embodiment, the first spot is imaged onto a second plane located between the focusing monochromator and the diminishing achromatic optical system, and the first and second planes are conjugate planes.

[0087] In one embodiment, the X-ray beam light source is arranged in the first plane.

[0088] In one embodiment, method 300 includes imaging a spot formed by an X-ray beam source onto a first plane using an imaging achromatic optical system.

[0089] Any steps of Method 200 and Method 300 may be combined.

[0090] In one embodiment, method 300 is performed by either the X-ray optical system shown in Figure 9 or Figure 10.

[0091] Various examples of other systems

[0092] The most commonly used X-ray energy in XPS is AlKα (1486.7 eV), which is typically delivered and focused to the wafer surface via a monochromator to narrow the natural line width of the emission line for chemical state identification. Since the maximum kinetic energy of photoelectrons generated by AlKα emission is ~1486.7 eV, the analysis depth is limited to ~10 nm, and the range of secondary X-ray fluorescence lines that can be detected simultaneously and used as an independent and complementary input parameter for the total dose of the analyzed material is limited. The most commonly used focusing monochromator systems consist of an ellipsoidal or toroidal substrate with a quartz diaphragm (see Figure 13), which provides point-to-point focus of the target emission onto the sample surface with an energy bandwidth of ~0.5 eV. The advantage of these systems is that they can produce monochromators with large angular acceptance, and therefore high transport efficiency. This type of monochromator focusing system can also be used for transport when optimized for first-order Bragg diffraction of AlKα, and can focus discrete high-order diffraction (energy) on the wafer surface according to nλ = 2d sin(θ) (d: lattice spacing).However, the range of focusable energies is inherently discontinuous, and intermediate energies other than those equivalent to nλ are not transported to the sampling area by design. The lower the X-ray energy, the less likely it is to reach the sample surface or focus using such a monochromator; therefore, the 2d grating spacing applied to the substrate must be increased.

[0093] The system can monochromatize and focus various X-ray wavelengths λ as given by hc / E, where h is Planck's constant, c is the speed of light, and E is the X-ray energy, which can be manufactured by applying crystals of various crystal plane orientations and / or crystalline materials to an ellipsoidal substrate. The limitation is that only X-ray energies following nλ=2d sin(θ) or E=n / [(hc)2d sin(θ)] are monochromatized and focused onto the wafer area with a low cutoff determined by the 2d crystal lattice spacing. The higher the first-order diffraction energy, the larger the energy difference of higher-order diffraction.

[0094] Generally, monochromatic crystals for high-energy regions require smaller two-dimensional (2d) lattice spacings and are readily available using a variety of crystal plane orientations and crystals. These crystals can be applied to a substrate to focus monochromatic X-rays onto a sampling area.

[0095] For X-ray energies requiring 2D lattice spacings of 27 Å or greater, natural crystals with clearly defined lattice structures are no longer available, and multilayer mirror monochromators are used. The multilayer can be deposited on a substrate, such as an ellipsoidal substrate, to focus the monochromatic X-ray beam from the X-ray source onto the sampling surface. A specific example is a W / Ti multilayer with a period of 1.4 nm and a relative layer thickness of 0.55 having 300 repeating layers on the substrate. For example, at an X-ray energy of 452.2 eV (TiLα), ideally, a maximum reflectivity of 25% is achieved at a Bragg angle of 78.3 degrees (CXRO website). This artificial multilayer on the substrate provides a monochromatic X-ray beam that can be focused onto the wafer substrate (see Figures 13 and 14).

[0096] Following this method, such a multilayer structure can be deposited onto other optical systems, such as a Schwarzschild objective lens with an appropriate focusing geometry, to provide a nearly monochromatic and focused beam spot in the target sampling region (see Figure 15). Since the Schwarzschild optical system requires a shape close to specular reflection, i.e., a Bragg angle in the range of 80 to less than 90 degrees, it can be mainly applied to the low-energy X-ray range in the water window.

[0097] Another type of energy-selective focusing system is zone plate optics, which are typically multilayer-based. This system can focus in Laue transmission mode (Figure 16 shows a schematic diagram of a multilayer zone plate with inclined interfaces to satisfy the Bragg angle) or reflection configuration. The principle involves arranging a group of concentric ellipses with a common focal point (light source-object) around the point of focus, designed to satisfy the Bragg diffraction condition over a larger diameter. n =sqrt[(nλ / 2) 2 [+nλf], where f is the focal length.

[0098] The resolution of a zone plate is determined by the width of its outermost zone.

[0099] To provide spatially separated X-ray images according to the incident wavelength of a polychromatic (multicolor) incident X-ray beam, reflection off-axis zone plate structures with an appropriate shape can be deposited on a substrate.

[0100] Non-energy selective (achromatic) focusing systems operate using total external or internal reflection. The most common focusing optical system for X-ray energies above 2-3 keV is the poly-capillary optics. This system consists of bundled glass capillaries and can be configured to provide point-parallel, parallel-point, or point-point focusing, utilizing total internal reflection (see Figure 17, schematic diagram of X-ray transport via poly-capillary lenses).

[0101] In the low-energy region, the effectiveness of polycapillary optics is generally lower than that of shaped reflective optics mirrors, which is due to the high critical angle of metal coating surfaces such as Pt. The above reflective optics can provide the same focusing conditions as polycapillary optics, namely point-parallel, parallel-point, and point-point focusing. The shape of the reflective optics for point-to-parallel X-ray transport is an effective parabolic surface with a shape that matches a given working distance, as shown in Figure 16. Single-bounce optics must employ a true parabolic shape and can achieve high efficiency in the X-ray energy range of several keV (depending on the metal coating). Type 1 to Type 3 Wolters optics utilize total internal reflection in a double-bounce geometry with nested parabolic and elliptical mirrors to focus a nearly parallel beam to a point (or conversely, to focus a parallel beam from a point) (see Figure 18, schematic diagram of X-ray transport by a reflective (Type I Wolters) optical system).

[0102] In some applications, combining a reflective Walters optical system with a polycapillary optical system can broaden the wavelength range of collimating and focusing optical systems (polycapillary optical systems within a Walters optical system).

[0103] The detailed description above includes numerous specific details to allow for a thorough understanding of the invention. However, those skilled in the art will understand that the invention can be implemented without these specific details. In other examples, well-known methods, procedures, and components are not described in detail so as not to obscure the invention.

[0104] The subject matter of this invention is specifically identified and explicitly claimed in the concluding section of the specification. However, this invention, along with its purpose, features and advantages, as well as its mechanism and method of operation, is best understood by referring to the following detailed description, along with the accompanying drawings.

[0105] It should be understood that, in order to simplify and clarify the illustration, the elements shown in the diagram are not necessarily drawn to scale. For example, the dimensions of some elements may be exaggerated relative to others for clarity. Furthermore, where deemed appropriate, reference numerals may be repeated in the drawing to indicate corresponding or similar elements.

[0106] Since the illustrated embodiments of this invention can be implemented in most cases using electronic components and circuits known to those skilled in the art, details beyond what is considered necessary, as illustrated above, will not be described in order to facilitate understanding and application of the fundamental concepts of this invention, and to avoid obscuring or diverting the teachings of this invention.

[0107] References to methods in this specification should apply mutatis mutandis to systems capable of performing those methods.

[0108] References to the system in this specification should be applied mutatis mutandis to methods that can be performed by the system.

[0109] The above specification has described the invention with reference to specific embodiments thereof. However, it will be apparent that various modifications and changes are possible without departing from the broad spirit and scope of the invention as described in the appended claims.

[0110] Furthermore, terms such as “front,” “rear,” “top,” “bottom,” “top,” and “bottom” in this specification and claims are used for descriptive purposes and are not necessarily used to describe permanent relative positions. It is understood that the terms used in this manner are interchangeable under appropriate circumstances, so that the embodiments of the invention described in this specification may operate in orientations other than those illustrated or otherwise described in this specification.

[0111] The connections described in this specification can be any type of connection suitable for signal transfer from or to each node, unit, or device, for example, via an intermediate device. Therefore, unless implicitly or otherwise stated, connections may be direct or indirect. Connections may be illustrated or described with reference to being single, multiple, unidirectional, or bidirectional. However, in different embodiments, the implementation of connections can vary. For example, separate unidirectional connections may be used instead of a bidirectional connection, and vice versa. Multiple connections may also be replaced by a single connection that transfers multiple signals in series or time-division multiplexing. Similarly, a single connection that transmits multiple signals may be separated into various different connections that transmit subsets of these signals. Thus, many options exist for signal transfer.

[0112] In the examples, specific conductivity types and potential polarity were described, but it should be understood that the conductivity type and potential polarity can be reversed.

[0113] Each signal described in this specification can be designed as either positive logic or negative logic. In the case of a negative logic signal, the signal is active-low, and the logically true state corresponds to logic level zero. In the case of a positive logic signal, the signal is active-high, and the logically true state corresponds to logic level 1. Note that the signals described in this specification can be designed as either negative logic or positive logic signals. Therefore, in other embodiments, a signal described as a positive logic signal can be implemented as a negative logic signal, and a signal described as a negative logic signal can be implemented as a positive logic signal.

[0114] Furthermore, the terms “assert” or “set” and “negate” (or “deassert” or “clear”) are used in this specification to refer to putting a signal, status bit, or similar device into a logically true or logically false state, respectively. If a logically true state is at logical level 1, then a logically false state is at logical level 0. Also, if a logically true state is at logical level 1, then a logically false state is at logical level 1.

[0115] Those skilled in the art will recognize that the boundaries between logic blocks are merely illustrative, and that in alternative embodiments, logic blocks or circuit elements can be integrated, or alternative decompositions of functions can be imposed on various logic blocks or circuit elements. Therefore, it should be understood that the architecture described in this specification is merely illustrative, and in practice, many other architectures can be implemented to achieve the same functionality.

[0116] The arrangement of components to achieve the same functionality is substantially “related” in such a way that the desired functionality is achieved. Therefore, in this specification, any two components combined to achieve a particular functionality can be considered “related” to each other, regardless of the architecture or intervening components, in such a way that the desired functionality is achieved. Similarly, any two components thus related can be considered to be “operably connected” or “operably coupled” to each other in such a way that the desired functionality is achieved.

[0117] Furthermore, those skilled in the art will recognize that the boundaries between the operations described above are merely illustrative. Multiple operations may be combined into a single operation, a single operation may be distributed among additional operations, and operations may be performed with at least partial overlap in time. Moreover, other embodiments may include multiple instances of a particular operation, and the order of operations may be modified in various other embodiments.

[0118] Furthermore, for example, in one embodiment, the illustrated embodiment may be implemented as a circuit arranged on a single integrated circuit or within the same device. Alternatively, the illustrated embodiment may be implemented as any number of separate integrated circuits or separate devices interconnected in an appropriate manner.

[0119] However, other modifications, variations, and substitutions are possible. Therefore, this specification and drawings should be considered illustrative rather than restrictive.

[0120] In the claims, reference numerals in parentheses should not be construed as limiting the claims. The phrase “comprising” does not preclude the existence of other elements or steps described in the claims. Furthermore, the terms “a” or “an” as used in this specification are defined as one or plural. Also, the use of introductory phrases such as “at least one” and “one or more” in the claims should not be construed as meaning that the introduction of another claim element by the indefinite article “a” or “an” limits a particular claim containing such introduced claim element to an invention containing only one such element, even if the same claim contains the introductory phrase “one or more” or “at least one” and an indefinite article such as “a” or “an”. The same applies to the use of definite articles. Unless otherwise stated, terms such as “first” and “second” are used to arbitrarily distinguish the elements described by such terms. Therefore, these terms are not necessarily intended to indicate the temporal or other priority of such elements. The mere fact that certain means are described in different claims does not mean that a combination of these means cannot be used advantageously.

[0121] While this specification illustrates and describes certain features of the invention, many modifications, substitutions, alterations, and equivalents will arise for those skilled in the art. Therefore, it should be understood that the attached claims are intended to cover all modifications and alterations that fall within the true spirit of the invention.

Claims

1. an achromatic collimating optical system configured to collimate an input X-ray beam and provide a collimated X-ray beam, (a) A tunable diffraction unit configured to receive a collimated X-ray beam when it is configured according to a current configuration associated with a current wavelength selected from a variety of wavelengths, and (b) to filter the collimated X-ray beam to provide a filtered collimated X-ray beam of the current wavelength, and It includes an achromatic focusing optical system configured to focus a filtering and collimated X-ray beam to provide a focused filtering X-ray beam. X-ray optical system.

2. The X-ray optical system according to claim 1, wherein the adjustable diffraction unit includes various diffracting elements associated with various wavelengths.

3. The X-ray optical system according to claim 2, wherein the various diffraction elements described above exhibit various lattice spacings.

4. The X-ray optical system according to claim 2, wherein the various diffracting elements described above exhibit various compositions.

5. The X-ray optical system according to claim 2, wherein the various diffraction elements are various planar diffraction gratings related to the various wavelengths mentioned above.

6. The X-ray optical system according to claim 2, wherein the various diffraction elements described above are arranged in a linear array, and the constituent unit is configured to move one of the various diffraction elements into the path of the collimated X-ray beam.

7. The X-ray optical system according to claim 2, wherein various diffraction elements are connected to a turret, and a component unit is configured to move one of the various diffraction elements into the path of the collimated X-ray beam.

8. The X-ray optical system according to claim 2, comprising various diffracting elements and various ellipsoidal monochromators associated with various wavelengths.

9. The X-ray optical system according to claim 2, further comprising the above-mentioned various diffraction elements and a reduction optical system.

10. The X-ray optical system according to claim 2, further comprising a component unit for selecting one of various diffraction elements that interact with the collimated X-ray beam described above.

11. The above adjustable diffraction unit Diffractive element, and A component unit configured to determine the Bragg condition of the above-mentioned diffraction element, The X-ray optical system according to claim 1, comprising:

12. The X-ray optical system according to claim 11, wherein the above-described unit is configured to set the optical axis of the collimated X-ray beam, the optical axis of the filtering collimated X-ray beam, and the distance between the diffracting element and at least one of the achromatic collimating optical system or the achromatic focusing optical system.

13. The X-ray optical system according to claim 12, wherein the above-described unit is configured to set the optical axis of the collimated X-ray beam by rotating the achromatic collimating optical system while maintaining a constant distance between the light source and the focal point, and to set the optical axis of the filtering collimated X-ray beam by rotating the achromatic focusing optical system.

14. The X-ray optical system according to claim 13, wherein the adjustable diffraction unit is composed of various diffracting elements related to various wavelengths, the various diffracting elements include diffracting elements, and the constituent unit is configured to select one of the diffracting elements that interacts with a collimated X-ray beam.

15. The input X-ray beam is collimated by an achromatic collimating optical system to provide a collimated X-ray beam. The collimated X-ray beam is received by an adjustable diffraction unit, which is selected from various configurations associated with various wavelengths, and is configured according to the current configuration associated with the current wavelength selected from various wavelengths. The adjustable diffraction unit described above filters the collimated X-ray beam to provide a filtered collimated X-ray beam of the current wavelength. The above filtering and collimated X-ray beam is focused by an achromatic focusing optical system to provide a focused filtering X-ray beam. A method for manipulating an input X-ray beam.

16. The method according to claim 15, wherein the adjustable diffraction unit comprises various diffracting elements associated with various wavelengths, and one of the various diffracting elements corresponds to the current configuration.

17. The method according to claim 15, wherein the adjustable diffraction unit comprises a diffraction element, and the configuration unit is configured to determine the Bragg condition of the diffraction element, and the Bragg condition corresponds to the current configuration.

18. The method according to claim 15, wherein the adjustable diffraction unit includes various diffracting elements associated with various wavelengths, and one of the various diffracting elements corresponds to the current configuration.

19. The method according to claim 15, wherein the adjustable diffraction unit comprises a diffracting element and a configuration unit configured to determine the Bragg condition of the diffracting element, the Bragg condition corresponding to the current configuration.

20. (i) A focusing monochromator configured to receive a non-collimated input X-ray beam that forms a first spot in a first virtual plane, and (b) to filter and focus the non-collimated X-ray beam to provide a filtered focused X-ray beam of the current wavelength, and The system includes a dilution achromatic optical system configured to dilute the above-mentioned filtered focused X-ray beam of the current wavelength to form a target spot smaller than the first spot on the sample surface. X-ray optical system.

21. The X-ray optical system according to claim 20, wherein the first spot described above is imaged onto a second plane located between the focusing monochromator and the diminishing achromatic optical system, and the first plane and the upper second plane are conjugate planes.

22. The X-ray optical system according to claim 21, wherein the X-ray source is arranged in the first plane described above.

23. The X-ray optical system according to claim 21, further comprising an imaging achromatic optical system configured to image a spot formed by an X-ray beam source onto the first plane.

24. The X-ray optical system according to claim 20, comprising various focusing monochromators associated with various wavelengths.

25. The X-ray optical system according to claim 20, wherein the focusing monochromator is an ellipsoidal monochromator.

26. The X-ray optical system according to claim 20, wherein the focusing monochromator is a toroidal monochromator.

27. A focusing monochromator receives a non-collimated input X-ray beam that forms a first spot on a first virtual plane. The above-mentioned focusing monochromator filters and focuses the above-mentioned non-collimated X-ray beam to provide a filtered and focused X-ray beam of the current wavelength. A reduction-of-magnification achromatic optical system reduces the current wavelength of filtered and focused X-ray beam to form a target spot smaller than the first spot on the sample surface. Methods for manipulating X-rays.

28. The method according to claim 27, wherein the first spot described above is imaged onto a second plane located between the focusing monochromator and the diminishing achromatic optical system, and the first plane and the second plane are conjugate planes.

29. The method according to claim 27, wherein the X-ray beam source is arranged in the first plane.

30. The method according to claim 27, wherein a spot formed by an X-ray beam source is imaged onto the first plane by an imaging achromatic optical system.

Images