Metrology using joint angle and wavelength scattering

Abstract

Embodiments of the present disclosure relate to metrology using joint angle and wavelength scatter. For example, a system can include a light source configured to generate light, a wavelength selection subsystem configured to select at least one wavelength of the light to be directed as a light beam to a sample having a periodic structure, and a diffraction detection subsystem to detect diffracted light beams from the sample. The light beam incident on the sample has an illumination direction and angular spread selected to separate incidence angle and wavelength in a diffraction pattern obtained from the sample. The periodic structure has a periodicity to obtain multi-angle and multi-wavelength information simultaneously from the diffracted light beams.

Description

Technical Field

[0001] Embodiments of this disclosure generally relate to metrology, and more specifically to metrology using combined angle and wavelength scattering. Background Technology

[0002] Substrates (such as wafers) can be processed for a wide variety of applications, including the manufacture of integrated devices and microdevices. One method of processing a substrate involves depositing a material, such as a semiconductor or conductive material, on the upper surface of the substrate. In the context of electronic devices, metrology refers to the measurement and characterization of various physical, chemical, and / or electrical properties during the manufacturing and inspection of electronic devices. Metrology can be used to ensure the quality, reliability, and performance of components in electronic devices, such as integrated circuits (ICs). Examples of metrology include critical dimension (CD) metrology for measuring the dimensions of features on a substrate (e.g., a wafer), thin film metrology for measuring thin film properties (e.g., thickness, uniformity, and / or material properties), overlap metrology for ensuring alignment of material layers during photolithography, and detection metrology for detecting and classifying defects that may occur during the manufacturing of electronic devices. Summary of the Invention

[0003] The following is a brief overview of this disclosure to provide a basic understanding of some aspects of it. This overview is not an exhaustive summary of this disclosure. It is not intended to identify any important or key elements of this disclosure, nor is it intended to depict any scope of any particular implementation of this disclosure or any scope of the claims. Its sole purpose is to present some concepts of this disclosure in a concise form as a prelude to the more detailed description that follows.

[0004] In some embodiments, a system includes: a light source configured to generate light; a wavelength selection subsystem configured to select at least one wavelength of the light to be guided as incident on a sample comprising a periodic structure having periodicity; and a diffraction detection subsystem configured to detect the diffracted beam from the sample. The beam incident on the sample has an illumination direction and angular spread selected to separate the incident angle and wavelength in a diffraction pattern obtained from the sample. Periodicity is used to simultaneously obtain angular spectral data corresponding to multi-angle information and wavelength spectral data corresponding to multi-wavelength information from the diffracted beam.

[0005] In some embodiments, a method includes: guiding a light beam toward a sample comprising a periodic structure having a periodicity; receiving diffraction data associated with the sample from a diffraction detection subsystem configured to detect the diffracted light beam from the sample; and characterizing the sample based on the diffraction data. The light beam incident on the sample has an illumination direction and angular spread selected to separate the incident angle and wavelength in a diffraction pattern obtained from the sample. Periodicity is used to obtain angular spectral data corresponding to multi-angle information and wavelength spectral data corresponding to multi-wavelength information from the diffracted beam.

[0006] In some embodiments, a device includes a double-sided grating structure having a diffraction region and a reflection region. The diffraction region includes a plurality of diffraction grating structures, and the reflection region includes a reflective element.

[0007] Several other features are provided based on these and other aspects of this disclosure. These other features and aspects of this disclosure will become more apparent from the following embodiments, claims, and drawings. Brief description of the attached diagram

[0009] This disclosure is illustrated by way of example in the accompanying drawings and is not intended to be limiting, in which like references designate similar elements. It should be noted that different references to "an" or "one" embodiments in this disclosure do not necessarily refer to the same embodiment, and such references imply at least one.

[0010] Figures 1 to 2C This is a diagram of an example system that can be used to implement metrology using combined angle and wavelength scattering, according to some embodiments.

[0011] Figures 3A to 3C This is a diagram illustrating example positions of diffraction orders for a sample having a one-dimensional (1D) periodic structure at various incident angles and wavelengths, according to some embodiments.

[0012] Figures 4A to 4C This is a diagram illustrating example positions of diffraction orders for a sample having a two-dimensional (2D) periodic structure at various incident angles and wavelengths, according to some embodiments.

[0013] Figure 5 This is a diagram of an example system that can be used to implement metrology using combined angle and wavelength scattering, according to some embodiments.

[0014] Figure 6 This is a diagram of an example layout of a diffraction pattern on a detection plane according to some embodiments.

[0015] Figures 7A to 9B This is a diagram illustrating an example implementation of a double-sided grating structure for metrology using combined angle and wavelength scattering, according to some embodiments.

[0016] Figure 10 This is a flowchart of an example method for implementing metrology using combined angle and wavelength scattering, according to some embodiments.

[0017] Figure 11 A graphical representation of a machine in the form of an example computing device is depicted, in which a set of instructions can be executed to cause the machine to perform any or more methodologies discussed herein. Detailed Implementation

[0018] The embodiments of this disclosure are for metrology using combined angle and wavelength scattering.

[0019] Performing metrology to characterize samples under test can be useful. Examples of samples include metals, ceramics, biological samples, etc. Samples may include at least one structure (e.g., a feature). For example, the structure of an electronic device (e.g., a semiconductor device) can be generated during the manufacture of the electronic device. One type of structure is a nanostructure. A nanostructure is a structure having dimensions that can be measured at the nanometer (nm) scale. For example, nanostructures can have dimensions varying from about 1 nm to about 100 nm. Examples of nanostructures include nanoparticles, nanowires, quantum dots, thin films, etc.

[0020] Characterizing a sample may include determining one or more properties of the sample. For example, one or more properties may include at least one of geometry, material composition, etc. Some techniques for determining one or more properties of a sample include performing a three-dimensional (3D) profile of the sample to generate a 3D structural profile of the sample. The 3D structural profile may include at least one of the following: the width, depth, and / or shape of the top layer elements, the thickness of the inner and / or main layers, the sample thickness, the sample composition, morphology, or phase.

[0021] Scanning electron microscopy (SEM) is a technique used to characterize samples and, more specifically, to image them. A key characteristic of SEM is its high spatial resolution, which allows for the characterization of samples, microstructural features, and surface defects at the nanoscale.

[0022] In addition to such surface characterization, SEM can be combined with energy-dispersive spectroscopy (EDS) to obtain semi-quantitative elemental composition information. While the top few nanometers of a sample can be analyzed at high resolution, the depth information provided by SEM is very limited and poses a significant challenge in structural and material analysis. The lack of reliable depth information hinders accurate material analysis, especially where 3D profiles of the sample are beneficial for thin film characterization, quality control, and failure analysis.

[0023] EDS can be performed by irradiating the sample with a predefined set of wavelengths and angles, recording the resulting reflected and scattered power, and analyzing the reflected and scattered power to estimate the properties of the structure. Typically, irradiation is performed using light with wavelengths in the ultraviolet (UV) to infrared (IR) range (e.g., light with wavelengths greater than about 50 nm).

[0024] However, as electronic devices become smaller and more complex, performing EDS using light with wavelengths in the UV to IR range may be impractical or impossible. Therefore, for smaller structures, it may be advantageous to perform EDS using light with wavelengths shorter than those in the UV to IR range to characterize the structure. For example, the light could have wavelengths in the extreme ultraviolet (EUV) to soft X-ray range (e.g., light with wavelengths varying from about 1 nm to about 50 nm). However, using shorter wavelength light (e.g., light with wavelengths in the EUV to soft X-ray range) can result in lower reflectance from the sample, which can lead to slower measurement times for characterizing the structure. Additionally, these techniques can be characterized by poor lateral resolution. More specifically, the resolution of EUV and / or soft X-ray microscopy can be limited by the numerical aperture of the lenses, thus restricting its resolution to the range of approximately tens of nanometers. Such a range may be too large to directly measure some samples, such as electronic devices.

[0025] In addition, some technologies involve scanning illumination angles. θ or irradiation wavelength λ The resulting diffraction patterns are recorded as parameters to obtain angular or wavelength spectra, respectively. Angular and wavelength spectra can be used to determine different properties of a sample. For example, angular spectra (e.g., from multiple illumination angles) θ Angular diffraction (OCD) can provide information about the geometry of a sample, while wavelength spectroscopy can provide information about the material composition. Combining these information sources provides a more complete sample characterization. Obtaining both angular and wavelength spectra can include scanning... θ To obtain multiple angular spectra at different wavelengths, and to scan λ To obtain multiple wavelength spectra at different angles. However, scanning individually using common scanning techniques... θ and λ The process can be very time-consuming.

[0026] The embodiments described herein address at least the aforementioned drawbacks by employing combined angular and wavelength scattering for metrology. These embodiments can be used to characterize the structure of a sample (e.g., nanostructures) by obtaining both angular and wavelength spectra more quickly than common techniques. For example, the embodiments described herein can be used to perform three-dimensional (3D) profiling of structures.

[0027] In some embodiments, the angular spectrum and wavelength spectrum can be obtained by acquiring multiple illumination angles simultaneously or almost simultaneously. θ and multiple light wavelengths λ To obtain, in order to determine (e.g., estimate) a set of properties of the structure. For example, multiple illumination angles. θ It can be used to determine the geometry of a sample, while multiple light wavelengths... λ It can be used to determine the material composition of a sample. In some embodiments, the wavelength of the light is in the range from EUV to soft X-rays (e.g., the wavelength of the light varies from about 1 nm to about 50 nm).

[0028] Using multiple wavelengths and / or multiple illumination angles (rather than a single wavelength and / or a single illumination angle) can be used to distinguish materials that have nearly identical properties at the same wavelength and / or illumination angle. For example, to illustrate the benefits of using multiple wavelengths, silicon (Si) can be identified by obtaining angular spectra at wavelengths greater than or less than 12 nm. Silicon-based compounds (such as silicon oxide (SiO2) and silicon nitride (Si3N4)) can have nearly identical optical properties at about 12 nm, meaning that they would be indistinguishable from each other at this wavelength. If it is desired to distinguish between samples containing SiO2 and samples containing Si3N4, it may be useful to perform measurements at wavelengths far from about 12 nm (e.g., about 10 nm and about 15 nm).

[0029] In some embodiments, the metrology system includes components for implementing diffraction-based metrology for characterizing one or more structures of a sample. In these embodiments, the sample may include a periodic structure, which may serve as a diffraction grating. In some embodiments, the sample includes a one-dimensional (1D) periodic structure that repeats periodically with respect to a single dimension. In some embodiments, the sample includes a two-dimensional (2D) periodic structure that repeats periodically with respect to two dimensions.

[0030] To achieve diffraction-based metrology for samples including periodic structures, the metrology system may include a light source capable of generating light for illuminating the sample. The light may have wavelengths in the range from EUV to soft X-rays (e.g., wavelengths varying from about 1 nm to about 50 nm).

[0031] In some embodiments, the light source is a discrete wavelength light source that generates a set of discrete wavelengths. For example, a discrete wavelength light source can generate discrete wavelength light based on high harmonic generation (HHG). HHG refers to a nonlinear optical process in which light (e.g., light having wavelengths in the EUV to soft X-ray range) is generated by irradiating a material with a strong laser beam. The laser field can interact with particles of the material (e.g., atoms, ions, and / or molecules), causing the particles to emit radiation at harmonics (i.e., multiples) of the fundamental laser frequency. The emitted harmonics can be phase-coherent, meaning that photons can be emitted in phase with each other to generate a coherent beam.

[0032] In some embodiments, the light source is a continuous wavelength light source. For example, a continuous wavelength light source can generate light of continuous wavelengths based on plasma discharge emission. Plasma discharge emission refers to radiation emitted from a plasma. This emission occurs when energy is applied to a gas (e.g., plasma generated by electrical or electromagnetic means, or by a strong laser beam—laser-produced plasma, LPP)), causing the gas to become conductive and form a plasma. When a plasma discharges, it can emit light and other forms of radiation.

[0033] The metrology system may further include a diffraction detection subsystem for detecting light reflected from the sample to obtain a diffraction pattern. For example, the diffraction detection subsystem may include a set of detectors (e.g., one or more detectors). For example, a detector may be a camera. In some embodiments, the diffraction detection subsystem is designed to achieve wavelength separation of the specular contribution of light reflected from the sample. For example, the set of detectors may include a positive diffraction order detector (e.g., a positive-side camera), a negative diffraction order detector (e.g., a negative-side camera), and a specular contribution detector (e.g., a specular contribution camera). The positive and negative diffraction order detectors may define a detection plane. A slit corresponding to the separation between the positive and negative diffraction order detectors may be defined. Specular contributions may pass through the slit to be received by a specular contribution separation element of the diffraction detection subsystem. The specular contribution separation element may be designed to redirect the specular contributions to the specular contribution detector. For example, the specular contribution separation element may include an auxiliary grating.

[0034] The metrology system may further include a system controller (“controller”) that can analyze diffraction patterns to characterize the sample. In some embodiments, the controller causes a light source to generate light for irradiating the sample. The light generated by the light source (e.g., in the EUV to soft X-ray range) can be inherently multi-angle and multi-wavelength. Combined with suitable structured or customized irradiation and collection conditions (e.g., source type, wavelength, and collection optics) to match the properties of the sample, processes for obtaining multiple angles and multiple wavelengths can be performed in parallel, thereby improving the number of acquisitions. Customization of irradiation and collection conditions can be accomplished so that the diffraction pattern can provide information about multiple incident angles and multiple wavelengths while reducing mixing. This configuration can be used with any subsequent processing of the information to characterize the sample. Reference will be made below. Figures 1 to 11 Further details are provided regarding the use of combined angle and wavelength scattering for metrology.

[0035] The embodiments of this disclosure provide various technical advantages. More specifically, the embodiments described herein can be used to obtain angular and wavelength spectra in an efficient manner, which can improve structure estimation capabilities.

[0036] Figure 1 This is a diagram of an example system 100 that can be used to implement metrology using combined angle and wavelength scattering. Figure 2A Figure 200 is a perspective view of part of system 100. Figure 2B It is a cross-sectional side view of a part of system 100, and Figure 2C This is a top-down view of a portion of a system 100 according to some embodiments. (See diagram below.) Figures 1 to 2C As shown, system 100 may include at least one light source 110, a diffraction detection subsystem 120, a system controller (“controller”) 130, a platform 135, and a test sample (“sample”) 140 located on the platform 135.

[0037] In some embodiments, system 100 includes components for implementing diffraction-based metrology for characterizing one or more structures of sample 140. In these embodiments, sample 140 may include periodic structures (e.g., structures 210-1 and 210-2), which may serve as diffraction gratings. In some embodiments, sample 140 includes 1D periodic structures that repeat periodically with respect to a single dimension. In some embodiments, the sample includes two-dimensional periodic structures that repeat periodically with respect to two dimensions. In this illustrative example, structures 210-1 and 210-2 are adjacent 1D periodic structures separated by a distance or structural period Λ. In some embodiments, Λ is less than or equal to about 100 nm.

[0038] To perform diffraction-based metrology with respect to sample 140, light source 110 can generate light for illuminating sample 140. The light generated by light source 110 can be inherently multi-angle and multi-wavelength. For example, the light generated by light source 110 can have wavelengths ranging from EUV to soft X-rays (e.g., wavelengths varying from about 1 nm to about 50 nm). In some embodiments, light source 110 is a discrete wavelength light source that generates a set of discrete wavelengths. For example, a discrete wavelength light source can generate discrete wavelength light based on HHG. In some embodiments, light source 110 is a continuous wavelength light source. For example, a continuous wavelength light source can generate continuous wavelength light based on plasma discharge emission.

[0039] System 100 may include a set of optical elements (e.g., lenses) to focus light from light source 110 onto sample 140. The set of optical elements may be used to reduce the spot size so that the spot size on sample 140 is smaller than the spot size of the light from light source 110. The optics may also include one or more mirrors for manipulating the light beam.

[0040] For example, the group of optical elements may include a wavelength selection subsystem 112. The wavelength selection subsystem 112 can control the wavelength range of light generated by the light source 110 reaching the sample 140. More specifically, the wavelength selection subsystem 112 may be configured to select at least one wavelength of the light generated by the light source 110 to be guided as a beam to the sample 140. In some embodiments, the wavelength selection subsystem 112 enables continuous selection of wavelengths from a set of based wavelengths. For example, the wavelength selection subsystem 112 may include a monochromator. In some embodiments, the wavelength selection subsystem 112 enables discrete selection of wavelengths from a set of discrete wavelengths. For example, the wavelength selection subsystem 112 may include a set of multilayer mirrors, wherein each multilayer mirror in the set is designed for a different center wavelength.

[0041] As another example, the optical array may further include an aperture controller 114 located between the light source 110 and the focusing element (e.g., between the wavelength selection subsystem 112 and the focusing element) to control the aperture. In some embodiments, the aperture controller 114 includes a tunable slit. For example, the tunable slit can dynamically control the illumination angle. As yet another example, the optical array may further include a focusing element 116 to focus light onto the sample. The focusing element 116 may define an angular range of incident light. The optical array may include... Figure 1 Other optical elements not shown in the diagram.

[0042] The diffraction detection subsystem 120 can be used to detect light reflected from the sample 140 to obtain a diffraction pattern. For example, the diffraction detection subsystem 120 may include a set of detectors (e.g., one or more detectors) with sufficient spatial resolution. In some embodiments, the detectors include cameras. Examples of cameras include charge-coupled device (CCD) sensor cameras, complementary metal-oxide-semiconductor (CMOS) sensor cameras, etc.

[0043] In some embodiments, the diffraction detection subsystem 120 is designed to achieve wavelength separation of the specular contribution of light reflected from the sample 140. More specifically, the focusing element 116 and / or aperture control 114 can be designed to generate a beam 118 guided toward the sample 140. In some embodiments, the beam 118 has a 1D converging beam shape, meaning it has a wide angular extension or range Δ in the longitudinal direction. θ And it has a narrow angular extension or range Δ in the azimuth direction. The beam of light.

[0044] The incident light beam 118 on sample 140 has an illumination direction and angular spread selected to separate the incident angle and wavelength in the diffraction pattern obtained from the sample. Unlike common reflectance measurement systems, the angular range (Δ) in the longitudinal direction... θ ) and the angular range (Δ) in the azimuth direction ) can be very different. For example, Δ θ It can be greater than about 10 degrees, while Δ It can be greater than about 1 degree. In some embodiments, aperture control 114 achieves control over Δ. θ and Δ Both are 2D controlled.

[0045] Platform 135 can be configured to translate in one or more directions (e.g., horizontally and / or vertically) to move sample 140. Additionally or alternatively, platform 135 can be configured to rotate to rotate sample 140. Thus, platform 135 can achieve control over both the measurement position and the direction of the incident beam 118. For example, platform 135 can control at least two rotation axes corresponding to the irradiation direction: principal azimuth rotation... and main longitudinal direction θ Each of these can be defined as a corresponding angle orthogonal to the center of beam 118. Therefore, The angle range is incident on sample 140. This range can be controlled by rotating sample 140 and / or by using aperture control 114.

[0046] The beam diffracted from sample 140 can then be used by diffraction detection subsystem 120 to generate diffraction data associated with sample 140. The diffraction data may include angular spectral data corresponding to multi-angle information and wavelength spectral data corresponding to multi-wavelength information. The periodicity of the periodic structure of sample 140 (e.g., the distance between periodic structures 210-1 and 210-2) can be used to obtain (e.g., simultaneously) angular spectral data and wavelength spectral data corresponding to multi-wavelength information from the beam diffracted from sample 140.

[0047] For example, for a single elevation angle θ Azimuth and wavelength λ The periodic structure of the illumination allows the beam 118 to diffract according to the vector grating equation. From the defined perspective, where It is the in-plane illumination vector. It is the in-plane diffraction direction vector. , It is a grating vector in reciprocal space, and , Integers. For example, having a period in the x-direction. In the case of a 1D structure, the grating vector is , For a periodicity in the x-direction And it has a periodicity in the y-direction. In the case of a 2D rectangular structure, the grating vector is , It can also calculate grating vectors for other structures with different orientations (e.g., hexagonal grids).

[0048] In some embodiments, longitudinal angle θ Compared to azimuth Carrying more information. For example, more information about the properties of sample 140 can be found in the longitudinal angular spectrum, while the azimuth variation can be relatively small. Thus, the focusing element 116 allows for an angular extension Δ. θ and Δ The two directions can be used for different purposes. For example, Δ θ The amount of information acquired in a single trigger (e.g., the fraction of the angular spectrum) can be controlled, and Δ θ It can be chosen to be as large as possible, as constrained by the optical elements of system 100. As another example, Δ The amount of light 118 incident on the sample 140 is controlled while carrying little or no information about the sample 140 itself.

[0049] Different positions of the diffraction detection subsystem 120 can correspond to different incident angles and diffraction orders. For each illumination angle incident on the sample 140, there will be several diffraction orders 150-1 and 150-2, as well as a specular contribution 160. Without loss of generality, diffraction order 150-1 can be a negative diffraction order (e.g., -1 diffraction order), and diffraction order 150-2 can be a positive diffraction order (e.g., +1 diffraction order). In some embodiments, and as will be referred to below... Figure 5 As described in further detail, the diffraction detection subsystem 120 includes multiple detectors for simultaneously or nearly simultaneously acquiring diffraction orders 150-1 and 150-2 and mirror contribution 160.

[0050] In a single-angle system, such diffraction orders are naturally separated. However, in a multi-angle system, there is a risk of overlap between diffraction orders, which can lead to information loss (e.g., in terms of angle). Incident and diffracted to level Light may be at an angle Incident and diffracted to level (Light overlap). For example, a large angular range can lead to overlap between diffraction orders.

[0051] System 100 can be designed so that such overlap between diffraction orders does not occur or is negligible. For example, a small azimuth rotation can be introduced. To increase the angular range and simultaneously shift the diffraction order, so that they do not overlap, even with a longitudinal angular span Δ θ Very large. This can be achieved by keeping the azimuth span Δ small enough. To achieve this. Increase Δ This can increase the signal-to-noise ratio (SNR). Typically, this may be limited by the distance between diffraction orders, and Δ This can be set to the maximum value of non-overlapping diffraction orders. More specifically, the focusing element 116 can be designed to allow a large longitudinal range Δ θ and small azimuth range Δ Therefore, the direction of illumination can be selected. θ , and angular extension Δ Δ θ This causes the incident angle and wavelength of beam 118 to separate from sample 140 in the diffraction pattern. For example, the angle range Δ can be selected. θ Δ This makes it possible for every pair of angle sets, and ,satisfy , The following relationship holds true: (1) and (2) Controller 130 can be used to control processes and methods, such as the methods described herein. Controller 130 may include processing devices (e.g., general-purpose computer processes, such as a central processing unit (CPU)), instruction-containing memory, and support circuitry for the processing devices. Controller 130 controls various items directly or via other computers and / or controllers. In some embodiments, controller 130 is communicatively coupled to a dedicated controller, and controller 130 functions as a central controller. Memory, or non-transitory computer-readable medium, is one or more readily available types of memory, such as random access memory (RAM), dynamic random access memory (DRAM), static RAM (SRAM), and synchronous dynamic RAM (SDRAM (e.g., DDR1, DDR2, DDR3, DDR3L, LPDDR3, DDR4, LPDDR4, etc.)), read-only memory (ROM), floppy disks, hard disks, flash drives, or any other form of digital storage (local or remote). Support circuitry of controller 130 is coupled to the processing devices. Supporting circuitry includes caches, power supplies, clock circuits, input / output circuitry systems, and subsystems, etc. Controller 130 is configured to perform any of the operations described herein. When executed by a processing device, instructions stored in memory cause any of the operations to be performed. The various operations described herein can be performed automatically using controller 130, or can be performed automatically and / or manually using certain operations performed by a user.

[0052] For example, controller 130 can analyze the diffraction pattern to characterize sample 140. Combined with suitable structured or customized illumination and collection conditions (e.g., source type, wavelength, and collection optics) to match the properties of the sample, processes obtaining multiple angles and multiple wavelengths can be performed in parallel, thus improving the number of acquisitions. Customization of illumination and collection conditions can be achieved, allowing the diffraction pattern to provide information about multiple incident angles and multiple wavelengths while reducing mixing. This configuration can be used with any subsequent processing of the information to characterize the structure.

[0053] The controller 130 can control one or more of the following: the light source 110, the wavelength selection subsystem 112, the diffraction detection subsystem 120, etc. For example, the controller 130 can cause the light source 110 to generate light for illuminating the sample 140. As another example, the controller can cause the wavelength selection subsystem 112 to select the wavelength of light. As yet another example, the controller 130 can control the operation of one or more detectors (e.g., cameras) in the diffraction detection subsystem 120.

[0054] Figures 3A to 3C This is a diagram illustrating example positions of diffraction orders for a sample with a 1D periodic structure at various incident angles and wavelengths, according to some embodiments. For example, Figure 3A Figure 300A shows example positions of diffraction orders 150-1 and 150-2 and the specular contribution 160 of the light reflected from sample 140, wherein =0. Figure 3B Figure 300B shows example positions of diffraction orders 150-1 and 150-2 and the specular contribution 160 of the light reflected from sample 140, in which =45°. Figure 3C Figure 300C shows example positions of diffraction orders 150-1 and 150-2 and the specular contribution 160 of the light reflected from sample 140, wherein... =90°. The diffraction angle of ±1st order is called... .

[0055] Figures 4A to 4C This is a diagram illustrating example positions of diffraction orders for a sample having a 2D periodic structure (e.g., a 2D rectangular periodic structure) at various incident angles and wavelengths, according to some embodiments. For example, Figure 4A Figure 400A shows example positions of diffraction orders 410-1 and 410-2 and the specular contribution 420 of light reflected from a sample 430 having a 2D periodic structure 440, wherein =0. Figure 4B Figure 400B shows example positions of diffraction orders 410-1 and 410-2 and the specular contribution 420 of light reflected from sample 430, wherein =45°. Figure 4C Figure 400C shows example positions of diffraction orders 410-1 and 410-2 and the specular contribution 420 of light reflected from sample 430, wherein =90°. The diffraction angle of ±1st order is called... .

[0056] If it is possible Figures 3A to 4C It can be observed that different sets of parameters can be found. θ , , λThis ensures that diffraction orders of different wavelengths and angles do not overlap. Under these conditions, both the angular spectrum and the wavelength spectrum can be extracted simultaneously. Care should be taken when selecting the illumination angle. For example, in the case of a 1D grating, when the illumination direction is perpendicular to the line (e.g., ...), ... Figure 3A and Figure 4A In If the diffraction angle is 0, diffraction at different wavelengths and angles will overlap, making equal separation difficult. This situation can be avoided by selecting an appropriate angle range.

[0057] Elevation angle θ It is possible Scan within the range, and wavelength λ It is possible Scanning within the range. Ideally, this can be accomplished in a single trigger. However, due to limitations imposed by system configuration and the periodicity of sample 140, the elevation angle and wavelength scans can be divided into several independent measurements. To minimize the number of acquisitions, the largest possible divergence elevation angle Δ can be selected. θ This avoids diffraction order overlap. The divergence azimuth angle Δ can be selected. This ensures that the amount of overlap between different wavelengths meets the threshold condition (e.g., no overlap).

[0058] Sample 140 has a 1D periodic structure and an azimuth angle =90° (for example, such as Figure 3C (As shown), elevation angle θ The wavelength can be inherently decoupled, and therefore the divergence elevation angle Δ can be obtained simultaneously. θ There is no limit to the range. However, the divergence azimuth angle Δ It should be small enough to achieve wavelength resolution Δ λ For example, this can be achieved by ensuring This means that the highest angle in the zeroth order will not overlap with the lowest angle in the first order.

[0059] Sample 430 has a 2D periodic structure 440 and an azimuth angle =90° (for example, such as Figure 4C As shown), the diffraction orders should not overlap. For example, this can be achieved by ensuring... This is to be accomplished. Furthermore, wavelengths within the same order should not overlap. For example, this can be achieved by ensuring… To complete.

[0060] For other angles and structure types, similar conditions can be found to guide the selection of the maximum angle and wavelength range at which the diffraction orders still do not overlap and there is sufficient separation within each order.

[0061] Another aspect to consider is the type of light source used (e.g., Figure 1 (Light source 110). For a light source providing a set of discrete wavelengths (e.g., based on HHG), it is possible to find the wavelength and azimuth angle. The condition for complete decoupling. Conversely, for light sources providing a continuous wavelength range (e.g., based on plasma discharge emission), the azimuth angle... There may not be a complete separation between the wavelength and the wavelength; instead, it can be chosen to be small enough to allow for a limited wavelength resolution Δ. λ azimuth range Δ As discussed above. In two cases, the elevation angle may be... θ Separated from wavelength.

[0062] One problem is, for satisfying , For diffraction orders >0, wavelength separation can occur naturally, while for mirror contributions ( There is no natural separation. The diffraction detection subsystem (e.g., Figure 1 The diffraction detection subsystem 120 can be designed to address this problem, providing separation for mirror contributions. For example, Figure 5 This is a diagram of an example system 500 that can be used to perform metrology using combined angle and wavelength scattering, according to some embodiments. As shown, system 500 may include a diffraction detection subsystem 120 and a sample 140.

[0063] The diffraction detection subsystem 120 may include detection plane detectors 510-1 and 510-2 defining a detection plane, and a specular contribution detector 520. More specifically, without loss of generality, detection plane detector 510-1 may be a positive diffraction-order detector (e.g., a front-side camera), and detection plane detector 510-2 may be a negative diffraction-order detector (e.g., a negative-side camera). The diffraction detection subsystem 120 may further include a specular contribution separation element 530. In some embodiments, and as shown in FIG2, the specular contribution separation element 530 includes an auxiliary grating. Specular contributions of light reflected from sample 140 may pass through a slit 515 having a slit length that separates detection plane detectors 510-1 and 510-2. D The mirror contribution separation element 530 can receive mirror contributions and can be designed to redirect mirror contributions to the mirror contribution detector 520. The mirror contribution separation element 530 can have properties that can provide maximum diffraction to the +1 order (e.g., orientation).

[0064] In this illustrative example, sample 140 includes a 1D periodic structure comprising adjacent structures 210-1 and 210-2, wherein the adjacent structures are defined by a distance or a structural period. Separation, as referenced above Figures 2A to 2C Description. In some embodiments, Less than or equal to approximately 100 nm.

[0065] If the detection plane is 140 units away from the sample L The slit width D It can be less than the distance L In some embodiments, L Less than or equal to approximately 1 meter (m). In some embodiments, L Less than or equal to approximately 75 centimeters (cm). In some embodiments, L Less than or equal to approximately 50 cm.

[0066] More specifically, slit width D It can be smaller than ,in λ This refers to the wavelength of light used to illuminate the sample at 140°. Slit width. This ensures that only the mirror contribution is transmitted through slit 515, while the diffraction order reaches the detection plane cameras 510-1 and 510-2. Slit 515 can be parallel to the elevation angle. θ Orientation (described in further detail below with reference to Figure 3) enables transmission of all incident angles.

[0067] The design of the mirror contribution separation element 530 (e.g., an auxiliary grating) can be independent of the sample 140 and can be optimized to provide high diffraction efficiency. The mirror contribution separation element 530 is perpendicular to the height angle. θ This expands the wavelength spectrum, thus achieving resolution in both the wavelength and angular spectra. This configuration helps balance the power between diffraction orders. For example, the power of the reflecting mirror is typically an order of magnitude stronger than the diffraction power, and therefore using different cameras to detect them can improve the detection gain balance.

[0068] As an illustrative example, if =100 nm, λ =13 nm, and the irradiation direction Parallel to the mirror surface, contributing separation element 530 ( =0°), then the diffraction angles of ±1st order can be: Illustratively, if the detection plane is placed at a distance of 140-100 mm from the sample, a separation width of 6.5 mm between detection plane cameras 150-1 and 150-2 ensures that only the specular component passes through slit 215, while all diffraction components reach detection plane cameras 150-1 and 150-2. The separation used can be varied according to the precise illumination angle and sample spacing.

[0069] Generally, positive diffraction-grade detectors (e.g., detection plane camera 150-1) detect... All diffraction orders, negative diffraction order detectors (e.g., detecting planar camera 150-2) All diffraction orders, and the mirror contribution detector 160 only detects For example, Figure 6 Figure 600 shows an example layout of the detection plane 610 according to some embodiments. Figure 600 illustrates the positions of the diffraction orders relative to the negative diffraction order detector 612, the positive diffraction order detector 614, and the mirror contribution detector 620. For different sample orientations ( ), diffraction order The position can be changed, and the slit width can be selected. D Let's consider this impact.

[0070] In some embodiments, the grating structure is used to implement Figures 1 to 2C At least one component of system 100 (e.g., at least one of wavelength selection subsystem 112 or diffraction detection subsystem 120). Standard grating structures can be used alone under specular reflection conditions to allow all zero-order wavelengths to pass through. However, common grating structures are designed to have higher first-order diffraction efficiency, resulting in less zero-order light reflection.

[0071] The embodiments described herein provide a double-sided grating structure. The double-sided grating structure can have diffraction regions and reflection regions, the diffraction regions having surfaces engineered for efficient diffraction to first order, and the reflection regions having mirrors (e.g., broadband grazing mirror surfaces) that can be independently engineered for high reflectivity. Each region or surface of the double-sided grating structure can be independently engineered to achieve maximum efficiency. Therefore, both modes can operate at maximum efficiency, with simple lateral shifting switching between modes. The advantage of imprinting the diffraction and reflection regions on the same structure (e.g., the same substrate) is that they are perfectly aligned with each other, and therefore switching between them can be accomplished by simple lateral shifting of the double-sided grating structure without any further calibration or adjustment of the system.

[0072] The following will be referenced. Figures 7A to 7C An example illustrating a double-sided grating structure. References will follow below. Figures 8A to 9B Describe an example implementation of a double-sided grating structure.

[0073] Figure 7AFigure 700A illustrates an example implementation of a double-sided grating structure 710 according to some embodiments. As shown, the double-sided grating structure 710 may include a diffraction region 720 and a reflection region 730, the diffraction region including a diffraction grating structure 722 and the reflection region including a reflection element (e.g., a mirror) 732. An incident beam 740 incident on the diffraction grating structure 722 may be split into a group of beams 745, wherein each beam in the group of beams 745 may have a corresponding wavelength (e.g., ...). λ １ , λ 2. ...) light. The incident light beam 750 incident on the reflective element 732 can be reflected without diffraction.

[0074] Figure 7B Figure 700B illustrates an example implementation of a double-sided grating structure 710 according to some embodiments. More specifically, Figure 700B illustrates a first type of double-sided grating structure 710 (e.g., type 1). As shown, the double-sided grating structure 710 may include a diffraction region 720 and a reflection region 730, the diffraction region including a diffraction grating structure 722 and the reflection region including a reflection element (e.g., a mirror) 732. An incident beam 740 incident on the diffraction grating structure 722 may be split into a set of beams 745, each of which may have a corresponding wavelength (e.g., ...). λ １ , λ 2, ...) light. The incident beam 750 incident on the reflective element 732 can be reflected without diffraction. In the first type of double-sided grating structure 710, the diffraction grating structure 722 is oriented such that rotation (e.g., for wavelength selection) is orthogonal to translation (e.g., for switching between modes). Figure 7B The number of diffraction grating structures 722 in the first type of double-sided grating structure 710 shown should not be considered a limitation.

[0075] Figure 7C Figure 700C illustrates an example implementation of a double-sided grating structure 710 according to some embodiments. More specifically, Figure 700C illustrates a second type of double-sided grating structure 710 (e.g., type 2). As shown, the double-sided grating structure 710 may include a diffraction region 720 and a reflection region 730, the diffraction region including a diffraction grating structure 722 and the reflection region including a reflection element (e.g., a mirror) 732. An incident beam 740 incident on the diffraction grating structure 722 may be split into a set of beams 745, each of which may have a corresponding wavelength (e.g., ...). λ １ , λ 2. λ3. ...) light. The incident beam 750 incident on the reflecting element 732 can be reflected without diffraction. In the second type of double-sided grating structure 710, the diffraction grating structure 722 is oriented such that rotation (e.g., for wavelength selection) is parallel to translation (e.g., for switching between modes). That is, the second type of double-sided grating structure can be relative to the above reference. Figure 7B The first type of grating structure described is oriented at 90 degrees. Figure 7C The number of diffraction grating structures 722 in the second type of double-sided grating structure 710 shown should not be considered a limitation.

[0076] Figures 8A to 8B This is a diagram illustrating an example implementation of a double-sided grating structure 710 for metrology using combined angle and wavelength scattering, according to some embodiments. More specifically, Figures 8A to 8B This is shown as a wavelength selection subsystem (e.g., Figure 1 The implementation method of the double-sided grating structure 710 of the wavelength selection subsystem 112).

[0077] For example, Figure 8A The figure illustrates system 800A, which includes a double-sided grating structure 710, a focusing element 116, and a sample 140 including structures 210-1 and 210-2, as referenced above. Figures 1 to 2C Described. In this example, a double-sided grating structure is placed at the light source ( Figure 8A In the illumination path between the incident beam 810 and the focusing lens 116 (not shown in the diagram), the incident beam 810 is incident on the diffraction grating structure 722 of the diffraction region 720 of the double-sided grating structure 710, and the wavelength is selected. λ 2 is the light beam 118 incident on sample 140. Thus, in this illustrative example, the double-sided grating structure 710 is configured as a wavelength selector, and the system 800A implements a single wavelength selection.

[0078] Figure 8B The figure illustrates system 800B, which includes a double-sided grating structure 710 and a sample 140 including structures 210-1 and 210-2, as referenced above. Figures 1 to 2C Described. In this example, the incident beam 810 is incident on the reflective element 732 of the reflective region 730 of the double-sided grating structure 710, and each wavelength ( λ １ , λ 2. Light (...) is incident on sample 140. Thus, in this illustrative example, the double-sided grating structure 710 is configured as a broadband (e.g., multi-wavelength) selector, and system 800B implements the broadband option.

[0079] Figures 9A to 9BThis is a diagram of an example embodiment of a double-sided grating structure 710 for achieving metrology using combined angle and wavelength scattering, according to some embodiments. More specifically, Figures 9A to 9B This is shown as a diffraction detection subsystem (e.g., Figure 1 The implementation of the double-sided grating structure 710 of the diffraction detection subsystem 120. In some embodiments, the double-sided grating structure 710 implements the above-referenced... Figure 5 The mirror contribution separation element 530 is described.

[0080] For example, Figure 9A The figure illustrates system 900A, which includes a double-sided grating structure 710 and a sample 140 including structures 210-1 and 210-2, as referenced above. Figures 1 to 2C Described. In this illustrative example, a diffracted beam 910 from sample 140 is incident on the diffraction region 720 of the double-sided grating structure 710 to provide spectral resolution to all diffraction orders.

[0081] Figure 9B The figure illustrates system 900B, which includes a double-sided grating structure 710 and a sample 140 including structures 210-1 and 210-2, as referenced above. Figures 1 to 2C Described. In this illustrative example, the diffracted beam 910 from sample 140 is incident on the reflective region 730 of the double-sided grating structure 710, so as not to provide spectral resolution to the mirror contribution, but to provide higher reflectivity to the other diffraction orders.

[0082] Figure 10 This is a flowchart of a method 1000 for performing metrology using combined angle and wavelength scattering, according to some embodiments. Method 1000 is performed by a system that may include hardware (circuit systems, dedicated logic, optical measurement tools such as those described herein), software (such as running on a general-purpose computer system or a dedicated machine), firmware, or some combination thereof. In some embodiments, method 1000 is performed by a system controller of the metrology system (such as...). Figure 1 The controller 130) performs the operation. In other or similar implementations, one or more operations of method 1000 may be performed by one or more other machines not depicted in the diagram.

[0083] At operation 1010, the processing logic causes a guide beam to be directed toward a sample having a periodic structure. In some embodiments, the size of the sample structure and / or the distance between adjacent structures (e.g., periodicity) varies from about 1 nm to about 1000 nm. In some embodiments, the size of the sample structure and / or the distance between adjacent structures (e.g., periodicity) varies from about 5 nm to about 100 nm. For example, causing the guide beam to be directed toward the sample may include causing a light source to generate light. A set of optical elements may receive light from the light source and generate a beam to be focused onto the sample. The light generated by the light source may be inherently multi-angle and multi-wavelength. For example, the light generated by the light source may have wavelengths in the EUV to soft X-ray range (e.g., wavelengths varying from about 1 nm to about 50 nm). The direction of illumination of the beam can be selected. and angular extension Δ Δ θ This is used to separate the incident angle and wavelength in the diffraction pattern to be obtained from the sample. In some embodiments, the light source is a discrete wavelength light source that generates a set of discrete wavelengths. For example, a discrete wavelength light source can generate discrete wavelength light based on HHG. In some embodiments, the light source is a continuous wavelength light source. For example, a continuous wavelength light source can generate continuous wavelength light based on plasma discharge emission.

[0084] At operation 1020, the processing logic receives diffraction data associated with the sample from the diffraction detection subsystem. More specifically, the diffraction data may define a diffraction pattern obtained from the sample. The diffraction data may include angular spectrum data and wavelength spectrum data. More specifically, the angular spectrum data may correspond to multi-angle information and the wavelength spectrum data may correspond to multi-wavelength information. The angular spectrum data and wavelength spectrum data may be obtained simultaneously or nearly simultaneously based on the known periodicity of the periodic structure of the sample. The diffraction detection subsystem may include a set of detectors (e.g., one or more detectors). For example, the detector may be a camera. In some embodiments, the diffraction detection subsystem includes multiple detectors. For example, the set of detectors may include a first diffraction order detector (e.g., a positive diffraction order detector) for receiving light associated with a first diffraction order, a second diffraction order detector (e.g., a negative diffraction order detector) for receiving light associated with a second diffraction order, and a mirror contribution detector for receiving light associated with mirror contribution. The first and second diffraction order detectors may define a detection plane. A slit corresponding to the separation between the first and second diffraction order detectors may be defined. Mirror contributions can pass through a slit to be received by the mirror contribution separation element of the diffraction detection subsystem. The mirror contribution separation element can be designed to guide the mirror contributions to the mirror contribution detector. For example, the mirror contribution separation element may include an auxiliary grating.

[0085] At operation 1030, the processing logic characterizes the sample based on diffraction data. More specifically, angular spectral data and wavelength spectral data (e.g., a combination of multi-angle and multi-wavelength information) can be used to characterize the sample. For example, characterizing the sample may include determining at least one property of the sample based on a combination of multi-angle and multi-wavelength information. Characterizing the sample may include at least one of the following: physical simulation of the structure, optimization methods, machine learning models trained to infer at least one property of the sample based on input diffraction data, etc. In some embodiments, characterizing the sample includes matching the measured spectrum with the predicted spectrum. For example, characterizing the sample may include changing the structure and material parameters of the predicted spectrum until a sufficiently close match is achieved with the measured spectrum, and outputting the resulting set of parameters. For the spectral prediction process, the processing logic may implement electromagnetic simulation, machine learning-based methods, etc. Parameter search may be based on any optimization method, such as gradient descent. Alternatively, machine learning-based optimization may be used, where, for example, the machine learning model may be trained on a previously obtained set of measurements or simulations to predict what the structure parameters of the sample are for a given measurement. Regardless of the exact implementation method used, the use of both angular and wavelength spectra can increase the number of constraints that the predicted spectrum should satisfy. This reduces the ambiguity between different estimates of the sample's structural parameters. Further details regarding operations 1010 to 1030 are referenced above. Figures 1 to 9B describe.

[0086] Figure 11 A graphical representation of a machine in the example form of computing device 1100 is depicted, within which a set of instructions can be executed to cause the machine to perform any or more methodologies discussed herein. In alternative embodiments, the machine may be connected (e.g., network-connected) to other machines in a local area network (LAN), intranet, extranet, or the Internet. The machine may operate in a client-server network environment within the capacity of a server or client machine, or as a peer machine in a peer-to-peer (or distributed) network environment. The machine may be a personal computer (PC), tablet computer, set-top box (STB), personal digital assistant (PDA), cellular phone, network device, server, network router, switch, or bridge, or any machine capable of executing a set of instructions (continuously or otherwise) specifying actions to be taken by the machine. Furthermore, although only a single machine is shown, the term "machine" should also be considered to include any set of machines (e.g., computers) that independently or jointly execute a set of instructions (or multiple sets of instructions) to perform any or more methodologies discussed herein. In this embodiment, the computing device 1100 may correspond to Figure 1 The controller 130.

[0087] Example computing system 1100 includes processing device 1102, main memory 1104 (e.g., read-only memory (ROM), flash memory, dynamic random access memory (DRAM) such as synchronous DRAM (SDRAM), etc.), static memory 1106 (e.g., flash memory, static random access memory (SRAM), etc.), and auxiliary memory (e.g., data storage device 1118), which communicate with each other via bus 1108.

[0088] Processing device 1102 may represent one or more general-purpose processors, such as microprocessors, central processing units, etc. More specifically, processing device 1102 may be a complex instruction set computing (CISC) microprocessor, a reduced instruction set computing (RISC) microprocessor, a very long instruction word (VLIW) microprocessor, a processor implementing other instruction sets, or a processor implementing combinations of instruction sets. Processing device 1102 may also be one or more special-purpose processing devices, such as application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), digital signal processors (DSPs), network processors, etc. Processing device 1102 may also be or include a system-on-a-chip (SoC), a programmable logic controller (PLC), or other types of processing devices. Processing device 1102 is configured to execute processing logic for performing the operations discussed herein.

[0089] The computing device 1100 may further include a network interface device 1122 for communicating with the network 1164. The computing device 1100 may also include a video display unit 1110 (e.g., a liquid crystal display (LCD) or a cathode ray tube (CRT)), an alphanumeric input device 1112 (e.g., a keyboard), a cursor control device 1114 (e.g., a mouse), and a signal generation device 1120 (e.g., a speaker).

[0090] Data storage device 1118 may include a machine-readable storage medium (or more specifically, a non-transitory computer-readable storage medium) 1124 thereon storing a set of one or more instructions 1126 embodying any one or more methodologies or functions described herein. A non-transitory storage medium refers to a storage medium other than a carrier wave. Instructions 1126 may also reside wholly or at least partially in main memory 1104 and / or processing device 1102, which also constitute computer-readable storage media, during their execution.

[0091] Although computer-readable storage medium 1124 is illustrated as a single medium in the example embodiment, the term "computer-readable storage medium" should be understood to include a single medium or multiple media (e.g., a centralized or distributed database, and / or associated caches and servers) storing one or more instruction sets. The term "computer-readable storage medium" should also be understood to include any medium capable of storing or encoding instruction sets for execution by a machine and causing the machine to perform any one or more methodologies of this disclosure. The term "computer-readable storage medium" should therefore be understood to include, but is not limited to, solid-state memory, as well as optical and magnetic media.

[0092] The foregoing description sets forth several specific details, such as examples of specific systems, components, methods, etc., to provide a good understanding of several embodiments of this disclosure. However, it will be apparent to those skilled in the art that at least some embodiments of this disclosure can be practiced without these specific details. In other instances, well-known components or methods are not described in detail and are presented in a simple block diagram format to avoid unnecessarily obscuring this disclosure. Therefore, the specific details set forth are merely illustrative. Specific implementations may vary from these exemplary details and are still contemplated within the scope of this disclosure.

[0093] Throughout this specification, references to "an embodiment" or "one embodiment" mean that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment. Therefore, the phrase "in one embodiment" appearing in various places throughout the specification does not necessarily refer to the same embodiment. Furthermore, the term "or" is intended to mean inclusive rather than exclusionary. When the terms "about" or "approximately" are used herein, this is intended to mean that the presented nominal values ​​are accurate within ±10%.

[0094] Although the operations of the methods described herein are illustrated and described in a specific order, the order of operations for each method can be changed, such that some operations can be performed in reverse order, or that some operations can be performed at least partially concurrently with other operations. In another embodiment, instructions or sub-operations of different operations can be performed intermittently and / or alternately.

[0095] It will be understood that the above description is intended to be illustrative and not restrictive. Numerous other embodiments will become apparent to those skilled in the art upon reading and understanding the above description. Therefore, the scope of this disclosure should be determined by reference to the full scope of the appended claims together with their equivalents.

Claims

1. A system comprising: The light source is configured to generate light; A wavelength selection subsystem is configured to select at least one wavelength of the light to be guided to be incident on a sample containing a periodic structure having a periodic structure, wherein the light beam incident on the sample has an illumination direction and angular spread selected to separate the incident angle and wavelength in a diffraction pattern obtained from the sample. and A diffraction detection subsystem is configured to detect a diffracted beam from the sample, wherein the periodicity is used to simultaneously obtain angular spectral data corresponding to multi-angle information and wavelength spectral data corresponding to multi-wavelength information from the diffracted beam.

2. The system of claim 1, wherein the diffraction detection subsystem further comprises: First diffraction order detector, associated with at least the first diffraction order; A second diffraction order detector is associated with at least a second diffraction order that is different from the first diffraction order; Mirror contribution detector, associated with mirror contribution; and The slit is located between the first diffraction-level detector and the second diffraction-level detector.

3. The system of claim 2, wherein the diffraction detection subsystem further includes a mirror contribution separation component configured to guide the mirror contribution to the mirror contribution detector.

4. The system of claim 3, wherein the mirror contribution separation component includes an auxiliary grating.

5. The system of claim 1, wherein the periodicity varies from about 5 nanometers (nm) to about 100 nm.

6. The system of claim 1, wherein the light source comprises a discrete wavelength light source.

7. The system of claim 1, wherein the light source comprises a continuous wavelength light source.

8. The system of claim 1, further comprising at least one double-sided grating structure having a diffraction region and a reflection region.

9. The system of claim 8, wherein the diffraction region comprises a plurality of diffraction grating structures, and wherein the reflection region comprises a reflection element.

10. The system of claim 8, wherein the wavelength selection subsystem includes the at least one double-sided grating structure, wherein the diffraction region of the at least one double-sided grating structure enables single-wavelength selection of the light generated by the light source, and wherein the reflection region of the at least one double-sided grating structure enables broadband wavelength selection of the light generated by the light source.

11. The system of claim 8, wherein the diffraction detection subsystem includes the at least one double-sided grating structure for receiving the diffraction beam from the sample.

12. The system of claim 1, further comprising at least one processing means operatively coupled to memory to perform the following steps: This causes the light source to generate the light; Receive diffraction data associated with the sample from the diffraction detection subsystem, wherein the diffraction data includes the angular spectrum data and the wavelength spectrum data; and The sample is characterized based on the diffraction data.

13. A method comprising: This results in a guiding beam directed toward a sample containing a periodic structure, wherein the beam incident on the sample has an illumination direction and angular spread selected to separate the incident angle and wavelength in a diffraction pattern obtained from the sample; A diffraction detection subsystem configured to detect a diffraction beam from the sample receives diffraction data associated with the sample, wherein the periodicity is used to obtain angular spectral data corresponding to multi-angle information and wavelength spectral data corresponding to multi-wavelength information from the diffraction beam. and The sample is characterized based on the diffraction data.

14. The method of claim 13, wherein the periodicity varies from about 5 nanometers (nm) to about 100 nm.

15. The method of claim 13, wherein directing the light beam toward the sample comprises causing a discrete wavelength light source to generate the light.

16. The method of claim 13, wherein directing the light beam toward the sample comprises causing a continuous wavelength light source to generate the light.

17. The method of claim 13, wherein the diffraction data is based on the separation of the diffraction beam and mirror contribution with respect to a set of diffraction orders.

18. An apparatus comprising: The double-sided grating structure has a diffraction region and a reflection region; The diffraction region comprises multiple diffraction grating structures; and The reflective region contains a reflective element.

19. The device of claim 18, wherein the plurality of diffraction grating structures are oriented such that rotation and translation are orthogonal.

20. The device of claim 18, wherein the plurality of diffraction grating structures are oriented such that rotation and translation are parallel.

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