Imaging of large surfaces by reflection Fourier opticography.

Abstract

Various embodiments include a Reflection Fourier Plicography Microscope (RFPM) device and methods of using an RFPM. In one example, the RFPM includes a multi-component light source configured to illuminate a surface. The multi-component light source has a plurality of individual light sources, each configured to operate independently. The RFPM further includes collection optics that receive illumination reflected, scattered, or otherwise redirected from the surface, and a sensor element that converts the optical energy received from the collection optics into an electrical signal output. Other devices, designs, and methods are disclosed.

Description

[Technical field]

[0001] Claiming priority This application claims the benefit of priority to U.S. patent application Ser. No. 62 / 942,636, filed Dec. 2, 2019, entitled “IMAGING LARGE SURFACES BY REFLECTIVE FOURIER PHOTOGRAPHY,” which is incorporated by reference in its entirety.

[0002] The disclosed subject matter relates generally to the field of detecting surface and near-surface defects (subsurface defects). More specifically, the disclosed subject matter relates to automated detection of defects using a reflectance Fourier opticography system. [Background technology]

[0003] Simultaneous camera inspection techniques for surfaces use either expensive cameras with a wide field of view and low resolution, or systems with high magnification and high resolution but a narrow field of view. For example, current machine vision techniques can only capture an entire surface (e.g., an area of ​​approximately 0.25 m2). 2 However, the ion exchange reaction (which may be a part of the ion exchange reaction) cannot be examined rapidly and with sufficient resolution.

[0004] One prior art system using transmission mode technology allows for high magnification techniques while using collection optics with a low numerical aperture, thereby allowing sampling of a larger image area. Referring to FIG. 1, a simplified transmission mode diagram shows a prior art transmission mode Fourier opticography microscope (TFPM) device 100 with multiple illumination in the form of a programmable LED array 110. The TFPM device 100 uses a conventional bright field microscope 120 with a programmable LED array 110 as a light source. The programmable LED array 110 can purposefully pattern the illumination 101 at the Fourier plane 109 of the sample 103. Light 105 from the sample 103 passes through a first optical lens 107 and a second optical lens 111 of the bright field microscope 120. An imaging device 115 receives the transmitted light 113. The imaging device 115 may include a camera. Image data obtained by the imaging device 115 is electrically coupled to a computing device 117. Image data is transferred from imaging device 115 to computing device 117 for processing and ultimately display on a monitor (not shown).

[0005] The LED array 110 includes a programmable controller (not shown, but understandable to one of ordinary skill in the art) configured to illuminate one or more light emitting diodes disposed on the surface of the LED array 110 in a predetermined pattern and sequence as a function of time. Thus, FIG. 1 illustrates a prior art system using Fourieropticography that allows the use of low numerical aperture (NA) objectives with a wide field of view (FOV). Even with low NA objectives, various light sources and light generation patterns allow the Fourieropticography device to achieve a high level of resolution across the image. In addition to the illustrated LED array 110, various prior art example Fourieropticography microscope devices also use illumination sources (e.g., LEDs) that can be tilted and repositioned relative to the sample.

[0006] However, while TFPM device 100 and similar prior art devices have many useful applications in transmission microscopy, TFPM device 100 is only useful for objects through which light can pass (e.g., biological samples). As such, TFPM device 100 is not adaptable to reflected light microscopy and imaging techniques. Moreover, TFPM device 100 is not easily adaptable to scanning samples having large surface areas, such as those discussed above.

[0007] The information provided in this section is intended to provide one of ordinary skill in the art with a context for the subject matter disclosed below and should not be construed as an admission of prior art. [Brief description of the drawings]

[0008] [Figure 1] FIG. 1 is a simplified diagram of a prior art transmission mode Fourier opticography microscope setup with multiplexed illumination in the form of a programmable LED array.

[0009] [Diagram 2] FIG. 2 illustrates an exemplary embodiment of a reflection-mode Fourier opticography microscope (RFPM) apparatus according to various embodiments of the disclosed subject matter.

[0010] [Figure 3A] FIG. 3A is a diagram illustrating another exemplary embodiment of an RFPM device according to various embodiments of the disclosed subject matter.

[0011] [Figure 3B] FIG. 3B illustrates an exemplary embodiment of a light source arrangement that may be used in the RFPM device of FIG. 3A. [Figure 3C] FIG. 3C illustrates an exemplary embodiment of a light source arrangement that may be used in the RFPM device of FIG. 3A. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] The following description includes illustrative examples, devices, and apparatuses to embody various aspects of the disclosed subject matter. In the following description, for purposes of explanation, numerous specific details are set forth to provide an understanding of various embodiments of the inventive subject matter. However, it will be apparent to those skilled in the art that various embodiments of the disclosed subject matter can be practiced without these specific details. Additionally, well-known structures, materials, and techniques have not been shown in detail in order to avoid obscuring the various illustrated embodiments.

[0013] The various exemplary embodiments described below focus on a reflection mode Fourier opticography microscope (RFPM) device. Upon reading and understanding the disclosure set forth herein, one of ordinary skill in the art will readily appreciate that the various techniques, designs, and examples may all be applied in various combinations. As an introduction to the subject matter, the following paragraphs briefly and generally describe a few embodiments, followed by a more detailed description with reference to the drawings.

[0014] Current inspection systems and methods used by manufacturers to inspect parts rely on techniques that include both human inspection to detect large defects in the part (e.g., having a "diameter" of approximately 500 μm or more) and machine inspection to inspect a small percentage of the surface of the part to detect small defects (e.g., approximately 10 μm or more). These inspection systems and methods used by various manufacturers (e.g., semiconductor process and metrology tool manufacturers) typically inspect only about 0.0003% to about 0.0007% of the surface of the part and use this small sample to extrapolate to estimate the quality of the entire part. By inspecting only this small percentage of the part, there is only about 2% to about 4% confidence that the inspected surface provides the actual quality status of the part. The reason why current systems and methods inspect only a small percentage is based on the physics of optics, as briefly described below.

[0015] As will be appreciated by those skilled in the art, microscope-based inspection systems typically use a microscope objective to collect light that passes through or reflects off an object. Those skilled in the art will recognize the Rayleigh limit of resolution, L R Recognize that (how small features a microscope can resolve) is based on the following mathematical formula:

number

number

[0016] However, as the NA increases, the depth of field (i.e., image depth) and visibility region decrease significantly. For example, according to the following formula, the depth of field (DOF) decreases as the square of the numerical aperture (NA):

number

[0017] For example, the apparatus and methods of the disclosed subject matter can inspect the entire surface of a part with similar resolution as standard microscope-based systems of the prior art, in less than about 30 minutes, and with approximately 13,000 times greater efficiency than the approximately 0.0003% to approximately 0.0007% sampling described above, thereby significantly improving measurement confidence and providing a level of confidence up to about 95% to about 99.9997%.

[0018] Various embodiments of the disclosed subject matter may be implemented, for example, to inspect hard surfaces (e.g., non-living, such as inorganic or non-organic) in reflectance mode. Surfaces may include, for example, various metal (e.g., aluminum or stainless steel), ceramic (e.g., alumina, Al2O3) surfaces, ceramic coated surfaces, elemental and compound semiconductor substrate surfaces, various types of plastics, glass surfaces (of various types known in the art), anodized surfaces, and oxidized surfaces, although many other types of surfaces and materials may be inspected using embodiments of the disclosed subject matter. As an example, a part may be approximately 559 mm in diameter (or other characteristic area dimension) (approximately 22 inches, with a surface area of ​​one side of approximately 0.25 m2). 2 ) It is also possible to inspect parts for defects having characteristic dimensions of about 5 μm to about 10 μm or more. In another embodiment, it is possible to inspect parts for defects having characteristic dimensions of about 5 μm to about 10 μm or more over an area of ​​up to several square meters.

[0019] Various embodiments of the disclosed subject matter may also be used to identify, for example, changes in material composition, changes in crystal structure, or grain boundaries within a material. Materials with different compositions or different crystal structures have different refractive indices as a property of the material. The refractive index affects how light reflects off and refracts within the material. Thus, different refractive indices produce different intensities of light impinging on the sensor, which allows for the detection of, for example, compositional or structural boundaries. Furthermore, when grain sizes of materials such as ceramics and metals are in the micron range, grain boundaries and other defects that would normally require much higher magnification to see can be detected using various embodiments of the disclosed subject matter. Furthermore, light scattered at grain boundaries captured at multiple light angles can produce images that identify grain boundary information, as well as larger defects, at a larger scale than conventional optical instruments can detect or identify.

[0020] The disclosed subject matter uses cameras with a wide field of view while providing high resolution. The described apparatus embodiments use incident light at multiple angles, both spatially and temporally generated, which are then computationally combined to increase resolution and inspect over a large surface area of ​​the part. As many incident beams impinge on the surface of the part being inspected, artifacts from a single, high intensity beam of light are also reduced or eliminated. The disclosed apparatus can use statistics and machine learning to have high confidence in the quality of the entire surface by examining only a portion of the surface. Additionally, various embodiments of the disclosed subject matter can be tuned to various types of lenses (e.g., objective lenses) and wavelengths to accommodate the specific application required. Additionally, various embodiments described herein can be automated to scan the entire surface. For example, in one embodiment, the RFPM device can be raster scanned or otherwise moved to different portions of the surface being inspected to increase the surface area being inspected. In another embodiment, the surface can be moved relative to the RFPM device. In yet another embodiment, the RFPM device can be raster scanned and the surface can be moved relative to the RFPM device at the same time. Additionally, various embodiments may have pre-defined criteria for parts to meet the criteria, thereby eliminating the need for an operator to make a decision regarding one or more detected defects.

[0021] In certain exemplary embodiments, the disclosed subject matter includes a reflection mode Fourier optics microscope (RFPM) device. The RFPM device operates in reflection mode and uses a multi-component light source (e.g., an LED array or other illumination source), a lens with collection optics to receive reflected and scattered light (light reflected or otherwise redirected from the surface) from the object under inspection, and a reflected light sensor. In various embodiments, the reflected light sensor may be offset at a specific angle relative to the normal (perpendicular to the surface). The system captures multiple images under different illumination conditions (e.g., semicircular illumination of a multi-component light source), both bright-field and dark-field imaging, and samples the Fourier space of the image of the surface. These images are then computationally reconstructed and stacked to increase resolution and reduce aberrations. After reconstruction, machine learning algorithms are used to examine the images for defects and determine the quality of the part according to a predetermined criterion.

[0022] Referring now to FIG. 2, a diagram of an exemplary embodiment of a reflectance mode Fourier optics microscope (RFPM) apparatus 200 in various embodiments of the disclosed subject matter is shown. The RFPM apparatus 200 is shown to include a light source array 210, collection optics 230, and a sample surface 203. The light source array 210 includes a plurality of individual light sources 210A, 210B, . . . 210N. In various embodiments, each of the individual light sources 210A, 210B, . . . 210N may include a plurality of substantially monochromatic light sources. The light source array 210 may include individual light sources having one or more wavelengths, one or more polarization states, or other characteristics. In certain exemplary embodiments, the individual light sources 210A, 210B, . . . 210N include individual LEDs of a particular wavelength, or a group of LEDs each of which is tunable to a range of wavelengths (e.g., ultraviolet or infrared) that includes a correlated color temperature (CCT) or non-visible color. In various embodiments, the individual light sources may include other types of non-visible light sources with wavelengths that extend into the ultraviolet range. Regardless of the type of light used, each individual light source 210A, 210B, . . . 210N can be programmably and individually activated (on or off).

[0023] The collection optics 230 includes an imaging lens 207 and a sensor element 209. Although the imaging lens 207 is shown as a biconvex lens, there is no such limitation and the imaging lens 207 may include one or more types of lenses, or lens groups, as known in the art. The imaging lens 207 is shown to have a full angle of the cone of light 205 incident on the lens. In certain exemplary embodiments, the imaging lens 207 may be used in place of or in combination with other optical elements, such as mirrors. In certain exemplary embodiments, the collection optics 230 includes a microscope objective lens. The sensor element 209 may include various types of light receiving elements (e.g., photodetectors) known in the art that convert received light energy into an electrical signal output. In certain exemplary embodiments, the sensor element 209 includes a CCD array.

[0024] The light source array 210 can be positioned at an angle 211 relative to the sample surface 203. The angle 211 can be fixed or variable depending on several factors that one of ordinary skill in the art would understand. In various embodiments, the angle 211 can be from 0° or near 0° to about 2°, about 3°, about 5° or more. Additionally, each of the individual light sources 210A, 210B,... 210N can have various amounts of beam divergence 201. The beam divergence can be at or near 0° (e.g., laser or LED sources) or can be greater than 0° for other types of light sources.

[0025] The collection optics 230 can be positioned at an angle 213 with respect to the sample surface 203. The angle 213 can be fixed or variable depending on several factors that one of ordinary skill in the art would understand. In various embodiments, the angle 213 can be from 0° or near 0° to about 2°, about 3°, about 5°, or more. In certain exemplary embodiments, the angle 213 is approximately the same as the angle 211 of the light source array 210. The collection optics 230 of the RFPM device 200 collects reflected light that is reflected or scattered back from the sample surface 203 toward the collection optics 230.

[0026] Thus, a series of images are taken, each resulting from illumination from, for example, a coherent light source, but with multiple light sources and therefore multiple angles of incidence, many of which may be available substantially simultaneously. RFPM device 200 can collect a series of images using various types of temporal and spatial patterning of light.

[0027] Thus, various imaging techniques can be realized using an optical arrangement similar to that of FIG. 2, and in various embodiments, without moving parts, by selecting and activating (turning on or off) appropriate light sources 210A, 210B, . . . 210N (e.g., LEDs) in the light source array 210 according to a predetermined temporal and spatial pattern. As a result, each individual light source, or a pattern of multiple individual light sources in the light source array 210, corresponds to illumination of the sample surface 203 at a unique angle or range of angles. Thus, the range of illumination angles that can be patterned is much larger than the range of angles passing through the collection optics 230, and thus is not fixed by the numerical aperture of the collection optics 230. As a result, illumination of the sample surface 203 by individual light sources closer to the center of the light source array 210 produces a bright field image, while illumination of the sample surface 203 by individual light sources closer to the periphery of the light source array 210 (outside the numerical aperture of the collection optics 230) produces a dark field image. Bright field and dark field images are known and understood by those skilled in the art.

[0028] By capturing a set of images in succession, for example with either half of the LEDs of the light source array 210 (e.g., across a selected line of symmetry), the RFPM device 200 can obtain phase differential measurements by differential phase contrast (DPC) techniques. Using DPC techniques, a quantitative phase difference is obtained from images captured with different light source patterns from the light source array 210. Thus, a quantitative phase is recovered from two images captured with, for example, complementary asymmetric illumination patterns. The difference between the two images is related to the phase differential of the sample surface 203 along the asymmetric axis. The DPC technique is therefore a partially coherent imaging technique (including only illumination from one LED, a coherent light source). Various patterning techniques possible with the use of the light source array 210 allow DPC measurements to be performed in the RFPM device 200 in substantially real time, along multiple asymmetric axes, and without the use of moving parts. Therefore, the DPC technique can be realized without any mechanical modifications to either the illumination side (light source array 210 side) or the detection (back-reflected or scattered) side (collection optics 230 side) of the RFPM device. Therefore, different illumination methods of the light source array 210 can be developed to accommodate different types of samples and imaging requirements.

[0029] Those skilled in the art of optics and light scattering in general will recognize that height information can be extracted by taking the phase difference or the phase difference of multiple images and using this information to extract height characteristics (e.g., the characteristic height dimension of a defect). In a reflected light microscope using bright field images, for example, two half-moon illuminations (e.g., left, right, top, bottom) can be used. In an off-axis illumination situation, the phase varies substantially linearly with the contrast. However, in a single image, both the phase and amplitude information are inseparably intertwined in the resulting signal, so that the phase cannot be extracted separately from the signal. Images obtained from different angles have the same amplitude contrast but different phase contrast. Thus, taking the difference between the images allows the phase contrast to be separated.

[0030] The phase may be related to height or depth in reflection mode and is given by the following equation:

number

number

[0031] The above description is generally valid for a single reflection (rather than a transmitted signal) and uses a similar set of mathematics, which, although more complex, can be used to extract similar information from a transmitted signal. In the case of a solid surface having a transparent coating, various types of reflections can occur, but those skilled in the art will recognize how such reflections can be included in the above equations.

[0032] 3A, a diagram of another exemplary embodiment of an RFPM device 300 in accordance with various embodiments of the disclosed subject matter is shown. The RFPM device 300 is shown to include a left light source array 310L and a right light source array 310R. Each light source array 310L, 310R includes a plurality of individual light sources (not shown, but may be the same or similar to the light source array 210 of FIG. 2). The left light source array 310L and the right light source array 310R are at one or more angles 301L and 301R, respectively, that are different angles relative to the angle of the opposing side. The respective angles 301L and 301R of the left light source array 310L and the right light source array 310R may be fixed or variable. Additionally, although not explicitly shown, the RFPM device 300 may include a beam splitter element such that at least one of the light source arrays 310L, 310R may be positioned substantially orthogonal to the light ray path of the collection optics 230. Such beam splitter designs are known in the relevant art. In other embodiments, the light source arrays may surround the collection optics 230 or may be disposed in a device that houses the collection optics 230. Additionally, although Figure 3A illustrates the left light source array 310L and the right light source array 310R as planar elements, no such limitation should be inferred, as discussed below with reference to Figures 3B and 3C.

[0033] 3B and 3C are diagrams illustrating exemplary embodiments of light source arrangements that may be used with the RFPM apparatus of FIG. 3A. FIG. 3B illustrates an arrangement 320 of a light source array 330 having a plurality of individual light sources 330A, 330B, . . . 330N. Thus, the bottom (e.g., the underside of the light source array 330 closest to the surface) is shown. The angle 331 between adjacent rows of individual light sources 330A, 330B, . . . 330N may be determined based on the number of individual light sources required for a given size and other characteristics of the surface to be inspected. Although the angle 331 is illustrated with adjacent rows of individual light sources 330A, 330B, . . . 330N approximately 45° apart from one another, no such limitation should be inferred to the angle 331.

[0034] Also, the individual light sources 330A, 330B, ... 330N may not be arranged in a linear fashion. The individual light sources may be arranged in various spatially periodic or non-spatially periodic arrangements (including random). For example, in certain exemplary embodiments, the individual light sources are arranged in concentric circles with each adjacent row having the same number of light sources as the previous or following row. In another specific exemplary embodiment, the individual light sources are arranged in concentric circles with each adjacent row having a greater or lesser number of light sources than the previous or following row. In yet another specific exemplary embodiment, the individual light sources are arranged in an Archimedes spiral or other geometric arrangement. Furthermore, the light source arrangement 330 may include locally flat surfaces (e.g., from the interior to the periphery of the arrangement). In other embodiments, the light source array 330 may include concave or convex surfaces, or may include combinations of any of the geometric shapes described above or considered.

[0035] For example, Figure 3 C 3A shows a three-dimensional side view 340 of the arrangement of RFPM devices 300 of FIG. 3A. In this side view, RFPM devices 300 are shown to have a substantially frusto-conical shape. Angle 341 may range from 0° or near 0° to 45° or more.

[0036] Upon reading and understanding the disclosed subject matter, one of ordinary skill in the art will recognize that various embodiments of an RFPM device can each be used to measure defects of various sizes on surfaces of various materials and over large surface areas (e.g., from a fraction of a square meter up to several square meters or more). For very large surfaces, the RFPM device may be mounted on various types of motion stages (e.g., xy stages or R-theta stages) known in the relevant art. In other embodiments, the sample itself may be moved relative to the RFPM device. Additionally, In other embodiments, both the sample and the RFPM device may be moved relative to one another. The resulting images may be processed and stitched together, for example by software, to form a single image. The size of the detected defects may range from about 50 nm to about 50 mm of a characteristic dimension of the detected defects. A total number of detected defects (e.g., over a predetermined size, such as about 5 μm to about 10 μm) per unit area may be determined. Additionally, various embodiments may be used to determine the overall roughness level (e.g., RMS roughness level, R RMS ) can be determined.

[0037] In yet other embodiments not expressly stated but which would be understood by one of ordinary skill in the art upon reading and understanding the disclosed subject matter, the various disclosed embodiments may also be used in various processing steps of semiconductor manufacturing. For example, the disclosed subject matter may be used in situ in or near a deposition processing chamber to monitor defects, film thickness, and roughness levels as one or more films are deposited on a substrate (e.g., a silicon wafer). Results from such in situ monitoring may then be reported to an end user in substantially real time, or may be captured and reported as a series of images over time.

[0038] One embodiment using various embodiments of RFPM by using one or more of the various embodiments disclosed herein includes, for example, the following: (1) The RFPM operator manually places the part to be inspected on a fixture that fixes the part's orientation. (2) An operator selects and initiates a program that implements and controls at least some of the aspects of the RFPM described above, the program may be implemented through a human machine interface or other graphical user interface. (3) RFPM automatically images the entire surface of the part or a predetermined portion (e.g., a predetermined percentage of the part sampled in a fixed location) (e.g., both 1 μm and larger 500 μm defects can be detected substantially simultaneously). (4) Once the requested data has been collected, the images are processed using computational methods known in the relevant art, for example, using machine learning techniques that have been used to analyze and quantify defects. (5) Based on a predetermined set of inputs (e.g., the number of defects per unit area above a predetermined size, the roughness level of the portion or entirety of the scanned part, and other inputs and parameters described herein), the computer program determines whether the part passes or fails inspection based on the program and the defects analyzed.

[0039] Methods such as those described above can be implemented in various types of devices, described in more detail below, including, for example, a computer programmed with one or more aspects of the disclosed subject matter described above in software, firmware, or as a hardware implementation, or a special purpose processor such as a microprocessor, a field programmable gate array (FPGA) or an application specific integrated circuit (ASIC).

[0040] Throughout this specification, multiple examples may implement components, operations, or structures described as a single example. Although individual operations of one or more methods are shown and described as separate operations, one or more of the individual operations may be performed simultaneously, and the operations need not be performed in the order shown. In an illustrated configuration, structures and functionality presented as separate components may be implemented as a combined structure or component. These and other variations, modifications, additions, and improvements are within the scope of the subject matter of this specification.

[0041] Certain embodiments have been described herein as including logic or multiple components, modules, or mechanisms. A module may constitute a software module (e.g., code embodied in a machine-readable medium or transmission signal) or a hardware module. A "hardware module" is a tangible unit capable of performing certain operations and configured or arranged in a particular physical manner. In various embodiments, one or more computer systems (e.g., a stand-alone computer system, a client computer system, or a server computer system) or one or more hardware modules of a computer system (e.g., a processor or processors) may be configured as a hardware module that is operated by software (e.g., an application or application portion) to perform certain operations described herein.

[0042] In some embodiments, a hardware module may be implemented mechanically, electrically, or a suitable combination thereof. For example, a hardware module may include dedicated circuitry or logic that is permanently configured to perform a particular operation. For example, a hardware module may be a dedicated processor such as a field programmable gate array (FPGA) or an ASIC.

[0043] A hardware module may also include programmable logic or circuitry that is temporarily configured by software to perform certain operations. For example, a hardware module may include software embedded in a general-purpose processor or other programmable processor. It will be appreciated that the decision to mechanically implement a hardware module in dedicated permanently configured circuitry or temporarily configured circuitry (e.g., configured by software) may be made based on cost and time considerations.

[0044] Thus, the term "hardware module" should be understood to encompass a tangible entity that is physically created and permanently configured (e.g., hardware) or temporarily configured (e.g., programmed) to operate in a particular manner or to perform a particular operation described herein. As used herein, a "hardware-implemented module" refers to a hardware module. Considering an embodiment in which the hardware modules are temporarily configured (e.g., programmed), each hardware module need not be configured or instantiated at any one instance in time. For example, if a hardware module includes a general-purpose processor configured by software to become a special-purpose processor, the general-purpose processor may be configured at different times as different special-purpose processors (e.g., including different hardware modules). Thus, the software may configure a processor, e.g., configure a particular hardware module at one instance in time, and configure a different hardware module at a different instance in time.

[0045] A hardware module can provide information to and receive information from other hardware modules. Thus, the described hardware modules may be considered to be communicatively coupled. When multiple hardware modules are present simultaneously, communication may be achieved between two or more hardware modules by transmission of signals (e.g., by appropriate circuits or buses). In embodiments in which multiple hardware modules are configured or instantiated at different times, communication between such hardware modules may be achieved, for example, by storage and retrieval of information in a memory structure accessible to the multiple hardware modules. For example, one hardware module may perform an operation and store the output of that operation in a communicatively coupled memory device. An additional hardware module may subsequently access the memory device and retrieve and process the stored output. A hardware module may also initiate communication with an input or output device or operate on a resource (e.g., collect information).

[0046] Various operations of the example methods described herein may be performed, at least in part, by one or more processors (e.g., software) that are temporarily configured or one or more processors that are permanently configured to perform the associated operations. Whether temporarily or permanently configured, such processors may constitute processor-implemented modules that operate to perform one or more operations or functions described herein. As used herein, a "processor-implemented module" refers to a hardware module that is implemented using one or more processors.

[0047] Similarly, the methods described herein may be at least partially processor-implemented, with a processor being an example of hardware. For example, at least some of the operations of the methods may be performed by one or more processors or processor-implemented modules. Furthermore, one or more processors may operate to support execution of related operations in a "cloud computing" environment or as a "software as a service" (SaaS). For example, at least some of the operations may be performed by a group of computers (as an example of machines including a processor), which are accessible through a network (e.g., the Internet) and one or more suitable interfaces (e.g., application program interfaces (APIs)).

[0048] The performance of certain operations may be distributed among one or more processors and may occur within one machine as well as spread across multiple machines. In some embodiments, one or more processors or processor-implemented modules may be located in one location (e.g., in a residential environment, an office environment, or a server farm). In other embodiments, one or more processors or processor-implemented modules may be distributed across multiple locations.

[0049] The term "or" as used herein may be interpreted inclusively or exclusively. Moreover, those skilled in the art will understand other embodiments upon reading and understanding the disclosure set forth herein. Moreover, those skilled in the art will readily understand, upon reading and understanding the disclosure set forth herein, that the various combinations of the techniques and examples set forth herein may all be applied in various combinations.

[0050] Although various embodiments have been described separately, these individual embodiments are not intended to be considered as independent techniques or designs. As described above, various parts of each may be interrelated and each may be used separately or in combination with other embodiments of the reflective Fourepticography system described herein. For example, although various embodiments of methods, operations and steps have been described, these methods, operations and steps may be used separately or in various combinations.

[0051] Thus, many modifications and variations are possible, as will be apparent to those skilled in the art upon reading and understanding the disclosure set forth herein. In addition to those enumerated herein, functionally equivalent methods and apparatuses within the scope of the present disclosure will be apparent to those skilled in the art from the foregoing description. Portions and features of some embodiments may be included in or substituted for other portions and features. Such modifications and variations are intended to be within the scope of the appended claims. Thus, the present disclosure is to be limited only by the terms of the appended claims, along with the full scope of equivalents to which the claims are entitled. It should also be understood that the terms used herein are for the purpose of describing particular embodiments only, and are not intended to be limiting.

[0052] The Abstract of the Disclosure is provided to allow the reader to quickly ascertain the technical disclosure. This Abstract is presented with the understanding that it will not be used to interpret or limit the scope of the claims. Furthermore, in the foregoing Detailed Description, it is noted that various features may be grouped together in an embodiment for the purpose of streamlining the disclosure. The disclosed methods should not be construed as limiting the scope of the claims. Thus, the following claims are hereby incorporated into the Detailed Description, with each claim standing on its own as a separate embodiment.

[0053] The following numbered examples are specific embodiments of the disclosed subject matter. Example 1 An embodiment of the disclosed subject matter describes a method of operating a reflectance mode Fourier opticography microscope (RFPM) to detect defects on a surface of a component, the method including: placing the component on a holding fixture of the RFPM; generating at least one illumination pattern from a multi-component light source configured to illuminate the surface, the multi-component light source having a plurality of individual light sources each operated independently, the at least one illumination pattern being selected from a plurality of patterns including a temporal pattern and a spatial pattern; collecting illumination redirected from the surface onto a sensor element; obtaining phase differential measurements from the illumination collected by the sensor element by a differential phase contrast (DPC) technique; determining an angle between an imaging axis from the surface to the sensor element; and determining at least height characteristics of one or more defects on the surface.

[0054] Example 2 example 11. The method of claim 1, further comprising raster scanning the at least one generated illumination pattern over an area of ​​the surface.

[0055] Example 3 3. The method of any of Examples 1 or 2, further comprising raster scanning over an area of ​​the surface by moving the part under the at least one generated illumination pattern.

[0056] Example 4 The method of any one of the preceding examples, further comprising: scanning the at least one generated illumination pattern over an area of ​​the surface; and raster scanning the area of ​​the surface by moving the part under the at least one generated illumination pattern.

[0057] Example 5 The method of any one of the preceding examples, wherein the area is at least about 0.25 mm of the surface. 2A method of selecting such that

[0058] Example 6 The method of any one of the preceding examples, further comprising determining at least one wavelength of a light source selected from the plurality of individual light sources.

[0059] Example 7 The method of any one of the preceding examples, wherein the at least one illumination pattern is selected to illuminate the surface at a plurality of angles of incidence.

[0060] Example 8 The method of any one of the preceding examples, wherein the temporal pattern and the spatial pattern are predetermined.

[0061] Example 9 The method of any one of the preceding examples, wherein selecting the temporal pattern includes selecting which of the plurality of individual light sources to activate and determining which of the selected plurality of individual light sources to activate in time relative to the remaining light sources of the selected individual light sources.

[0062] Example 10 The method of any one of the preceding examples, wherein selecting the spatial pattern includes selecting which of the plurality of individual light sources to activate within a substantially constant time period.

[0063] Example 11 The method of any one of the preceding embodiments, further comprising determining a predetermined angle from a normal to the surface, the angle at which a midpoint of the at least one generated illumination pattern is offset from the normal (standard).

[0064] Example 12 The method of any one of the preceding examples, further comprising computationally combining at least one of the redirected collected illuminations from the surface to increase resolution of the detected defects and the wavelength of light of the plurality of individual light sources for a Rayleigh resolution limit for a given numerical aperture.

[0065] Example 13 The method of any one of the preceding examples, further comprising selecting collection optics for focusing the collected illumination onto the sensor element from a predetermined numerical aperture.

[0066] Example 14 The method of any one of the preceding examples, wherein the multi-component light source includes an LED array.

[0067] Example 15 The method of any one of the preceding examples, wherein generating the at least one illumination pattern includes selecting light sources from the plurality of individual light sources to include a group of LEDs from the LED array.

[0068] Example 16 The method of any one of the preceding examples, wherein each of the plurality of individual light sources includes an LED.

[0069] Example 17 An embodiment of the disclosed subject matter describes a method of operating a reflectance mode Fourier opticography microscope (RFPM) that includes placing a non-biological part to be inspected on a fixture and selecting a program for implementing and controlling one or more aspects of the RFPM, selectable from aspects including a spatial pattern of a multi-component light source, a temporal pattern of the multi-component light source, a size range of defects to detect, an area of ​​the part to inspect, at least one height characteristic of one or more detected defects, and a number of images of the non-biological part to record.

[0070] Example 18 18. The method of example 17, further comprising determining a roughness level of at least a portion of the region of the part based on the recorded images.

[0071] Example 19 The method of any one of Examples 17 and 18, further comprising selecting a size range of the defects to detect.

[0072] Example 20 The method of any one of Examples 17 to 19, further comprising selecting a range of angles of illumination that the multi-component light source directs toward the part.

[0073] Example 21 The method of any one of Examples 17 to 20, wherein the non-biological component comprises at least one material selected from materials including a metal surface, a ceramic surface, a ceramic-coated surface, an elemental semiconductor substrate surface, a compound semiconductor substrate surface, a glass surface, an anodized surface, a plastic, and an oxidized surface.

[0074] Example 22 22. The method of any one of claims 17 to 21, wherein the size range of the detected defects comprises a range of characteristic dimensions of the detected defects from about 50 nm to about 50 mm.

[0075] Example 23 An embodiment of the disclosed subject matter describes a method of operating a reflectance mode Fourier opticography microscope (RFPM) to detect defects on a surface of a component, the method including: generating at least one illumination pattern from a multi-component light source configured to illuminate the surface, the multi-component light source having a plurality of individual light sources, each of the multi-component light sources configured to operate independently, the at least one illumination pattern being selected from a temporal pattern and a spatial pattern, using both bright field and dark field imaging to sample a Fourier space of an image of the surface, collecting redirected illumination from the surface onto a sensor, obtaining phase differential measurements from the redirected illumination collected by the sensor in an area proximate the defect by a differential phase contrast (DPC) technique, determining an angle between an imaging axis from the surface to the sensor, and determining at least a height characteristic of one or more defects on the surface.

[0076] Example 24 24. The method of example 23, wherein a characteristic dimension of the detected defects is greater than or equal to about 5 μm over an area of ​​up to several square meters.

[0077] Example 25 The method according to any of Examples 23 and 24, wherein the part is a non-biological part.

[0078] Example 26 The method of Example 25, wherein the non-biological component comprises at least one material selected from materials including a metal surface, a ceramic surface, a ceramic-coated surface, an elemental semiconductor substrate surface, a compound semiconductor substrate surface, a glass surface, an anodized surface, a plastic, and an oxidized surface.

[0079] Example 27 The method of any one of Examples 23 to 26, wherein the spatial pattern is selected to illuminate the surface at multiple angles of incidence substantially simultaneously within a selected spatial pattern of time.

[0080] Example 28 The method of any one of Examples 23 to 27, wherein selecting the temporal pattern includes selecting which of the plurality of individual light sources to activate and determining which of the selected plurality of individual light sources to activate in time relative to the remaining light sources of the selected individual light sources.

[0081] Example 29 The method of any one of Examples 23 to 28, wherein selecting the temporal pattern includes selecting which of the plurality of individual light sources to activate within a substantially constant time period.

Claims

1. 1. A method of operating a reflectance mode Fourier opticography microscope (RFPM) to detect defects on a surface of a component, comprising: An operator places the part on a holding fixture of the RFPM; generating, by a computer, at least one illumination pattern from a multi-component light source configured to illuminate the surface, the multi-component light source having a plurality of individual light sources each individually activated, the at least one illumination pattern being selected from a plurality of patterns including a temporal pattern and a spatial pattern, the plurality of temporal patterns and the spatial pattern being generated by selecting individual light sources from the multi-component light source to be activated to illuminate the part at a predetermined range of angles of incidence; collecting, by a computer, illumination redirected from said surface using a sensor element; obtaining, by a computer, differential phase contrast (DPC) measurements from the illumination collected by the sensor elements; determining, by a computer, an angle between an imaging axis from the surface to the sensor element; determining, by a computer, at least a height characteristic of one or more defects on the surface.

2. 2. The method of claim 1 , The method further comprising raster scanning, by a computer, the at least one generated illumination pattern over an area of ​​the surface.

3. 2. The method of claim 1 , The method further comprising raster scanning over an area of ​​the surface by moving the part under the at least one generated illumination pattern by a computer.

4. 10. The method of claim 1 , further comprising: scanning the at least one generated illumination pattern over an area of ​​the surface; moving the part under the at least one generated illumination pattern; raster scanning over the area of ​​the surface by

5. 2. The method of claim 1, wherein the area on the surface to be inspected is at least about 0.25 mm of the surface. ２ A method of selecting such that

6. 10. The method of claim 1, further comprising determining, by a computer, at least one wavelength of a light source selected from the plurality of individual light sources.

7. The method of claim 1 , wherein the at least one illumination pattern is selected to illuminate the surface at a plurality of angles of incidence.

8. The method of claim 1 , wherein the temporal pattern and the spatial pattern are predetermined.

9. 2. The method of claim 1, wherein selecting the temporal pattern comprises: selecting which of the plurality of individual light sources to activate; determining which of the selected plurality of individual light sources to activate in time with respect to the remaining light sources of the selected individual light sources; A method comprising:

10. 2. The method of claim 1, wherein selecting the spatial pattern comprises selecting which of the plurality of individual light sources to activate within a substantially constant time period.

11. 10. The method of claim 1, further comprising determining, by a computer, a predetermined angle from a normal to the surface, the angle at which a midpoint of the at least one generated illumination pattern is offset from the normal.

12. 10. The method of claim 1, further comprising computationally combining, by a computer, at least one of the redirected and collected illuminations from the surface to increase the resolution of the detected defects and the wavelength of light of the multiple individual light sources for a Rayleigh resolution limit for a given numerical aperture.

13. 10. The method of claim 1, further comprising selecting, by a computer, collection optics for focusing the collected illumination onto the sensor element from a predetermined numerical aperture.

14. The method of claim 1 , wherein the multi-component light source comprises an LED array.

15. 15. The method of claim 14, wherein generating the at least one illumination pattern comprises selecting light sources from the plurality of individual light sources to include a group of LEDs from the LED array.

16. The method of claim 1 , wherein each of the plurality of individual light sources comprises an LED.

17. 1. A method of operating a reflection mode Fourier opticography microscope (RFPM), comprising: An operator places a non-living part to be inspected on the fixture; an operator selecting a program for implementing and controlling one or more aspects of the RFPM; The aspect can be selected from aspects including a spatial pattern of a multi-component light source, a temporal pattern of the multi-component light source, a size range of defects to detect, an area of ​​the part to inspect, at least one height characteristic of one or more detected defects, and a number of images of the non-biological part to record, wherein the temporal pattern and the spatial pattern are generated by selecting individual light sources of the multi-component light sources to be activated to illuminate the part at a range of predetermined angles of incidence; A method of executing the selected program by a computer.

18. 20. The method of claim 17, further comprising: determining a roughness level of at least a portion of the region of the part based on the recorded images by a computer executing the selected program.

19. 20. The method of claim 17, further comprising selecting a size range of defects to detect by a computer executing the selected program.

20. 20. The method of claim 17, further comprising: selecting a range of angles of illumination for the multi-component light source to direct at the part by a computer executing the selected program.

21. 20. The method of claim 17, wherein the non-biological component comprises at least one material selected from materials including a metal surface, a ceramic surface, a ceramic coated surface, an elemental semiconductor substrate surface, a compound semiconductor substrate surface, a glass surface, an anodized surface, a plastic, and an oxidized surface.

22. 20. The method of claim 17, wherein the size range of detected defects comprises a range of a characteristic dimension of the detected defects from about 50 nm to about 50 mm.

23. A computer-implemented method of operating a reflectance mode Fourier opticography microscope (RFPM) to detect defects on a surface of a component, comprising: generating at least one illumination pattern from a multi-component light source configured to illuminate the surface, the multi-component light source having a plurality of individual light sources, each of the multi-component light sources configured to be individually activated, the at least one illumination pattern being selected from a temporal pattern and a spatial pattern, the plurality of temporal patterns and spatial patterns being generated by selecting individual light sources from the multi-component light source to be activated to illuminate the part at a predetermined range of angles of incidence; using both bright field and dark field imaging to sample a Fourier space of an image of the surface; collecting illumination redirected from said surface with a sensor; obtaining differential phase measurements from the redirected illumination collected by the sensor in an area near the defect using a differential phase contrast (DPC) technique; determining an angle between an imaging axis from the surface to the sensor; determining at least a height characteristic of one or more defects on said surface; A method comprising:

24. 24. The method of claim 23, wherein a characteristic dimension of the detected defects is greater than or equal to about 5 μm over an area of ​​up to several square meters.

25. 24. The method of claim 23, wherein the part is a non-biological part.

26. 26. The method of claim 25, wherein the non-biological component comprises at least one material selected from materials including a metal surface, a ceramic surface, a ceramic coated surface, an elemental semiconductor substrate surface, a compound semiconductor substrate surface, a glass surface, an anodized surface, a plastic, and an oxidized surface.

27. 24. The method of claim 23, wherein the spatial pattern is selected to illuminate the surface at multiple angles of incidence substantially simultaneously within a selected spatial pattern of time.

28. 24. The method of claim 23, wherein selecting the temporal pattern comprises: selecting which of the plurality of individual light sources to activate; determining which of the selected plurality of individual light sources to activate in time with respect to the remaining light sources of the selected individual light sources; A method comprising:

29. 24. The method of claim 23, wherein selecting the temporal pattern comprises selecting which of the plurality of individual light sources to activate within a substantially constant time period.

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