Reflective fourier ptychography imaging of large surfaces

Abstract

To solve the problem in which: a Fourier ptychographic microscope (TFPM) apparatus in a transmissive mode is not adaptable to reflective microscopy and imaging techniques, and further, the TFPM apparatus is not readily adaptable to scanning samples having large surface areas.SOLUTION: Various embodiments include reflective-mode Fourier ptychographic microscope (RFPM) apparatuses and methods for using the RFPM. In one example, the RFPM includes a multiple-component light source configured to direct radiation to a surface. The multiple-component light source has a number of individual-light sources, each of which is configured to be activated individually. The RFPM further includes collection optics to receive radiation reflected or scattered from the surface or otherwise redirected from the surface, and a sensor element to convert received light-energy received from the collection optics into an electrical-signal output. Other apparatuses, designs, and methods are disclosed.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] Priority Claim This application claims the benefit of priority of U.S. Patent Application No. 62 / 942,636, entitled "Imaging of Large Surfaces by Reflective Fourier Ptychography", filed on Dec. 2, 2019, which is hereby incorporated by reference in its entirety.

[0002] The disclosed subject matter generally relates to the field of detecting surface and subsurface defects (defects beneath the surface). More specifically, the disclosed subject matter relates to the automated detection of defects using a reflective Fourier ptychography system.

Background Art

[0003] In surface simultaneous camera inspection techniques, either an expensive camera with a wide field of view and low resolution, or a system with high magnification and high resolution but a narrow field of view is used. For example, current machine vision techniques cannot rapidly inspect an entire surface (e.g., even if the area is approximately 0.25 m 2 or the like) with sufficient resolution.

[0004] One prior art system using through-mode technology enables high magnification technology while using a condenser optical system with a low numerical aperture, thereby enabling sampling of a wider range of image regions. Referring to FIG. 1, as a schematic diagram of the through mode, it is shown that a prior art through-mode Fourier ptychographic microscope (TFPM) apparatus 100 has multiple illuminations in the form of a programmable LED array 110. The TFPM apparatus 100 uses a conventional bright-field microscope 120 with a programmable LED array 110 as a light source. The programmable LED array 110 can intentionally pattern the illumination 101 at the Fourier plane 109 of the sample 103. The light 105 from the sample 103 passes through the first optical lens 107 and the second optical lens 111 of the bright-field microscope 120. The imaging device 115 receives the transmitted light 113. The imaging device 115 may include a camera. The image data obtained by the imaging device 115 is electrically coupled to the computing device 117. The image data is transferred from the imaging device 115 to the computing device 117 for processing and finally displayed on a monitor (not shown).

[0005] The LED array 110 includes a programmable controller (not shown but understandable to those skilled 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 time series as a function of time. Thus, FIG. 1 shows a prior art system using Fourier ptychography that can use an objective lens with a small numerical aperture (NA) and a wide field of view (FOV). Even with an objective lens with a small NA, due to various light sources and light generation patterns, a high level of resolution can be obtained across the entire image in a Fourier ptychography apparatus. In addition to the illustrated LED array 110, in examples of various prior art Fourier ptychographic microscope apparatuses, an illumination source (e.g., an LED) that can be tilted or repositioned with respect to the sample is also used.

[0006] However, even though the TFPM apparatus 100 and similar prior art apparatuses have many useful applications in a transmission microscope, the TFPM apparatus 100 is useful only for objects through which light can pass (e.g., biological samples). Therefore, the TFPM apparatus 100 is not adaptable to reflection microscopy and imaging techniques. Further, the TFPM apparatus 100 is not easily adaptable to scanning samples having a large surface area as described above.

[0007] The information described in this section is for presenting the context to those skilled in the art for the subject matter disclosed below and should not be regarded as admitted prior art.

Brief Description of the Drawings

[0008]

Figure 1

[0009]

Figure 2

[0010]

Figure 3A

[0011]

Figure 3B

Figure 3C

Embodiments for Carrying Out the Invention

[0012] The following description includes examples, devices, and apparatuses by way of illustration to embody various aspects of the disclosed subject matter. In the following description, for purposes of explanation, numerous specific details are set forth in order to provide an understanding of various embodiments of the subject matter of the present invention. However, it will be apparent to one skilled in the art that the various embodiments of the disclosed subject matter may be practiced without these specific details. Further, well-known structures, materials, and techniques are not shown in detail in order not to obscure the various exemplary embodiments.

[0013] The various exemplary embodiments described below are focused on a reflection-mode Fourier ptychographic microscope (RFPM) apparatus. By reading and understanding the disclosure described herein, one skilled in the art will readily appreciate that the various techniques, designs, and examples can 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 components rely on techniques that include human inspection to detect large defects in the component (e.g., having a "diameter" of approximately 500 μm or more) and machine inspection to inspect a small percentage of the surface of the component to detect small defects (e.g., approximately 10 μm or more). These inspection systems and methods used by various manufacturers (e.g., manufacturers of semiconductor processes and metrology tools) generally inspect only about 0.0003% to about 0.0007% of the surface of the component, and use this small sample to estimate the quality of the entire component by extrapolation. The reliability that the actual quality situation of the component can be obtained from the inspected surface by inspecting only such a small percentage of the component is only about 2% to about 4%. The reason that current systems and methods inspect only a very small percentage of the parts is based on the physics of optics, as briefly described below.

[0015] As will be understood by those skilled in the art, microscope-based inspection systems typically use a microscope objective lens to collect light passing through or reflected from an object. Those skilled in the art recognize that the Rayleigh resolution limit L R (how small a feature the microscope can resolve) is based on the following formula.

Equation

Equation

[0016] However, as NA increases, the depth of field (e.g., the depth of the image) and the visible area decrease significantly. For example, according to the following formula, the depth of field DOF decreases by the square of the numerical aperture NA.

Equation

[0017] For example, the apparatus and method of the disclosed subject matter can inspect the entire surface of a component with a resolution similar to that of a standard microscope-based system according to the prior art. In less than about 30 minutes, an effectiveness of more than about 13,000 times is obtained for the sampling from about 0.0003% to about 0.0007% described above, thereby significantly improving the reliability of the measurement and providing a reliability level of up to about 95% to about 99.9997%.

[0018] Various embodiments of the disclosed subject matter are performed, for example, to inspect a hard surface (e.g., a non-biological such as an inorganic or non-organic substance) in a reflection mode. The surface can include, for example, various metals (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 (various types known in the art), anodized surfaces, and oxidized surfaces. However, many other types of surfaces and materials can also be inspected using the embodiments of the disclosed subject matter. As an example, the component may have a diameter (or other characteristic area dimension) of approximately 559 mm (approximately 22 inches, and the surface area of one side is about 0.25 m 2 ). Also, defects of components having characteristic dimensions of about 5 μm to about 10 μm or more can be inspected. In other embodiments, defects of components having characteristic dimensions of about 5 μm to about 10 μm or more can be inspected over an area of up to several square meters.

[0019] Various embodiments of the disclosed subject matter can also be used, for example, to identify changes in the material composition within a material, changes in the crystal structure, or particle boundaries. Materials having 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, the various refractive indices produce various intensities of light that impinge on the sensor, thereby enabling, for example, the detection of compositional or structural boundaries. Further, when the particle size of materials such as ceramics and metals is on the micron scale, particle boundaries and other defects that typically require a fairly high magnification for visual inspection can be detected using the various embodiments of the disclosed subject matter. Further, light scattered at particle boundaries that is captured at multiple angles of light can generate an image that identifies information about the particle boundaries, in addition to larger defects, on a larger scale than can be detected or identified by conventional optical instruments.

[0020] The disclosed subject matter uses a camera with a wide field of view and at the same time high resolution. Embodiments of the described apparatus use incident light at multiple angles generated both spatially and temporally, which is then computationally combined to increase the resolution and inspect over a large surface area of the part. Since many incident light beams impinge on the surface of the part being inspected, artifacts from normal single and high-intensity light rays are also reduced or eliminated. The disclosed apparatus can use statistics and machine learning and has a high confidence regarding the quality of the entire surface with an inspection of only a part of the surface. Further, various embodiments of the disclosed subject matter can vary various types of lenses (e.g., objective lenses) and wavelengths and can accommodate specific applications required. Further, various embodiments described herein can be automated to scan the entire surface. For example, in one embodiment, the RFPM apparatus may be raster scanned or alternatively moved to different parts of the surface being inspected to increase the surface area to be inspected. In another embodiment, the surface may be moved relative to the RFPM apparatus. In yet another embodiment, the RFPM apparatus may be raster scanned while at the same time moving the surface relative to the RFPM apparatus. Further, various embodiments may have predetermined criteria for parts that meet the standards, thereby eliminating the need for an operator to make a determination regarding one or more detected defects.

[0021] In certain exemplary embodiments, the disclosed subject matter includes a reflection mode Fourier ptychographic microscopy (RFPM) apparatus. The RFPM apparatus operates in reflection mode and includes a light source with multiple components (e.g., an LED array or other illumination source), a lens including a condensing optical system for receiving reflected light and scattered light (reflected light from the surface or light redirected from the surface in other cases) from the object being inspected, and a reflected light sensor. In various embodiments, the reflected light sensor may be offset at a particular angle with respect to a perpendicular line (perpendicular to the surface). This system captures multiple images in both bright field imaging and dark field imaging under different illumination conditions (e.g., semi-circular illumination of a light source with multiple components) and samples the Fourier space of the surface image. These images are then computationally reconstructed, overlaid to increase resolution and reduce aberrations. After reconstruction, a machine learning algorithm is used to examine the defects in the images 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 reflection mode Fourier ptychographic microscopy (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, a condensing optical system 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 groups of LEDs each having a range of wavelengths that includes a correlated color temperature (CCT) or non-visible color (e.g., ultraviolet or infrared) that can be adjusted. In various embodiments, the individual light sources may include other types of non-visible light sources having wavelengths extending into the ultraviolet region. Regardless of the type of light used, each of the individual light sources 210A, 210B, ··· 210N is programmable and individually operable (turned on or off).

[0023] The light-gathering optical system 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 as is known in the art, the imaging lens 207 may include one or more types of lenses, or a lens group. The imaging lens 207 is shown as having the full angle of the light cone 205 incident on the lens. In certain exemplary embodiments, the imaging lens 207 may be replaced with, or used in combination with, other optical elements such as mirrors. In certain exemplary embodiments, the light-gathering optical system 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 the 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 arranged at an angle 211 with respect to the sample surface 203. The angle 211 may be fixed or variable depending on several factors that can be understood by those skilled in the art. In various embodiments, the angle 211 may be from 0° or near 0° to about 2°, about 3°, about 5°, or greater. Further, each of the individual light sources 210A, 210B, ··· 210N may have various amounts of beam spread 201. The beam spread may be 0° or near 0° (e.g., a laser or LED source), or greater than 0° for other types of light sources.

[0025] The light-gathering optical system 230 can be arranged at an angle 213 with respect to the sample surface 203. The angle 213 may be fixed or variable depending on several factors that can be understood by those skilled in the art. In various embodiments, the angle 213 may be from 0° or near 0° to about 2°, about 3°, about 5°, or greater. In certain exemplary embodiments, the angle 213 is approximately the same as the angle 211 of the light source array 210. The light-gathering optical system 230 of the RFPM apparatus 200 collects the reflected light reflected or scattered back from the sample surface 203 toward the light-gathering optical system 230.

[0026] Accordingly, a series of images are each captured, for example, as a result of illumination from a coherent light source. However, since there are multiple light sources, there are also multiple incident angles, and many of them can be used substantially simultaneously. The RFPM device 200 can collect a series of images using various types of temporal and spatial patterning of light.

[0027] Therefore, various image diagnostic techniques are realized using an optical device similar to that of FIG. 2. In various embodiments, without moving components, appropriate light sources among the individual light sources 210A, 210B, ··· 210N (e.g., LEDs) in the light source array 210 are selected and operated (turned on or off) according to a predetermined temporal and spatial pattern. As a result, each of the individual light sources, or the pattern of a plurality of individual light sources in the light source array 210, corresponds to the illumination of the sample surface 203 at a specific angle or angle range. Accordingly, the range of illumination angles that can be patterned is much larger than the angle range passing through the condenser optical system 230, and thus is not fixed by the numerical aperture of the condenser optical system 230. As a result, illumination of the sample surface 203 by an individual light source closer to the center of the light source array 210 generates a bright-field image, while illumination of the sample surface 203 by an individual light source closer to the outer periphery of the light source array 210 (outside the numerical aperture of the condenser optical system 230) generates a dark-field image. Bright-field images and dark-field images are known and understood by those skilled in the art.

[0028] By successively imaging a set of images with, for example, the LEDs in either half of the light source array 210 (e.g., with respect to a selected axis of symmetry), the RFPM apparatus 200 can obtain differential phase measurements by differential phase contrast (DPC) techniques. By using DPC techniques, a quantitative phase difference can be obtained from images captured with different light source patterns from the light source array 210. Thus, for example, a quantitative phase is reconstructed from two images captured with complementary asymmetric illumination patterns. The difference between the two images is related to the phase differential of the sample surface 203 along the axis of asymmetry. DPC techniques are thus partially coherent imaging techniques (including illumination from only one LED, a coherent light source). With the various patterning techniques made possible by the use of the light source array 210, DPC measurements can be performed in the RFPM apparatus 200 substantially in real time, along multiple axes of asymmetry, without using moving parts. Therefore, DPC techniques can be realized without making mechanical modifications to either the illumination side (light source array 210 side) or the detection (back-reflected or scattered) side (condensing optical system 230 side) of the RFPM apparatus. Thus, various illumination methods of the light source array 210 can be developed to accommodate various types of samples and imaging requirements.

[0029] Those of ordinary skill in the general field of optics and light scattering recognize that height information can be extracted by taking the phase difference between two or more images and using this information to extract height characteristics (e.g., the characteristic height dimensions of defects). In a reflection microscope using bright-field images, for example, two semi-circular illuminations (e.g., left, right, top, bottom) can be used. In the case of off-axis illumination, the phase varies substantially linearly with contrast. However, in a single image, both phase information and amplitude information are intertwined inseparably within the resulting signal, and as a result, the phase cannot be separated and extracted from the signal. Multiple images obtained from different angles have the same amplitude contrast but different phase contrasts. Therefore, taking the difference between the images can separate the phase contrast.

[0030] The phase may be related to height or depth in the reflection mode and is represented by the following mathematical formula.

Equation

Equation

[0031] The above description is generally valid for single reflection (not the transmitted signal). Using a similar series of mathematics, although it becomes more complex, it can be used to extract similar information from the transmitted signal. When the solid surface is coated with a transparent coating, various types of reflection can occur. However, those skilled in the art will recognize how such reflections can be included in the above formula.

[0032] Referring now to FIG. 3A, a diagram of another exemplary embodiment of the RFPM apparatus 300 in various embodiments of the disclosed subject matter is shown. The RFPM apparatus 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, which may be the same as 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 each at one or more angles 301L and 301R that are different angles with respect to the opposite side angles. 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. Further, although not explicitly shown, the RFPM apparatus 300 may include a beam splitter element such that at least one of the light source arrays 310L, 310R can be arranged substantially orthogonal to the optical path of the condenser optical system 230. The design of such a beam splitter is known in the relevant art. In other embodiments, the light source array may surround the condenser optical system 230 or may be arranged in a device that houses the condenser optical system 230. Further, FIG. 3A shows that the left light source array 310L and the right light source array 310R are planar elements, but such a limitation should not be inferred as will be described with reference to FIGS. 3B and 3C below.

[0033] FIGS. 3B and 3C are diagrams showing exemplary embodiments of the arrangement of light sources that can be used with the RFPM apparatus of FIG. 3A. FIG. 3B shows an arrangement 320 of a light source array 330 having a plurality of individual light sources 330A, 330B, ··· 330N. Thus, the re-lower part (e.g., the lower side of the light source array 330 closest to the surface) is shown. The angle 331 between adjacent columns of the individual light sources 330A, 330B, ··· 330N can be determined based on the number of individual light sources that require a predetermined size and other characteristics of the surface to be inspected. The angle 331 is shown to be approximately 45° apart from each other in adjacent columns of the individual light sources 330A, 330B, ··· 330N, but such a limitation should not be inferred for the angle 331.

[0034] Also, the individual light sources 330A, 330B, ··· 330N do not have to be arranged linearly. The individual light sources may be arranged in various spatial periodic or non-spatial periodic arrays (including random). For example, in a particular exemplary embodiment, the individual light sources are arranged in concentric circles such that each adjacent row has the same number of light sources as the row in front or behind. In another particular exemplary embodiment, the individual light sources are arranged in concentric circles such that each adjacent row has more or fewer light sources than the row in front or behind. In yet another particular exemplary embodiment, the individual light sources are arranged in an Archimedes spiral or other geometric arrangement. Further, the light source arrangement 330 may include a locally flat surface (e.g., from the inside to the outer periphery of the array). In other embodiments, the light source array 330 may include a concave or convex surface, or a combination of any of the geometries described or contemplated above.

[0035] For example, FIG. 3B shows a three-dimensional side view 340 of the arrangement of the RFPM device 300 of FIG. 3A. In this side view, the RFPM device 300 is shown to have a substantially frustoconical shape. The angle 341 may be 0° or near 0° up to 45° or more.

[0036] By reading and understanding the disclosed subject matter, one of ordinary skill in the art will recognize that various embodiments of the RFPM device can each be used to measure defects of various sizes on the surfaces of various materials over a large surface area (e.g., from a portion of 1 square meter up to several square meters or more). For very large surfaces, the RFPM device may be mounted on various types of moving stages known in the relevant art (e.g., an x-y stage or an R-θ stage). In other embodiments, the sample itself may be moved relative to the RFPM device. Further In other embodiments, both the sample and the RFPM device may be moved relative to each other. Each of the images obtained as a result may be processed, for example, stitched together by software to form one image. The range of the size of the detected defect may be from about 50 nm to about 50 mm of the characteristic dimension of the detected defect. The total number of detected defects per unit area (e.g., over a predetermined size such as from about 5 μm to about 10 μm) can be detected. Further, using various embodiments, the overall roughness level (e.g., RMS roughness level, R RMS ) of all or a part of the surface can be determined.

[0037] Although not explicitly stated, it will be understandable to those skilled in the art that in still other embodiments, based on reading and understanding the disclosed subject matter, the various disclosed embodiments can also be used in various processing steps of semiconductor manufacturing. For example, the disclosed subject matter can be used in-situ to monitor defects, film thickness, and roughness level when one or more films are deposited on a substrate (e.g., a silicon wafer) within or near a deposition processing chamber. The results obtained by such in-situ monitoring can be reported to the end user substantially in real time or acquired and reported as a series of images over time.

[0038] By using one or more of the various embodiments disclosed herein, one embodiment using various embodiments of RFPM includes, for example, the following. (1) The operator of the RFPM manually places the part to be inspected on a fixture that fixes the orientation of the part. (2) The operator selects and starts a program that executes and controls at least some of the above-described aspects of the RFPM. The program can be executed by a human-machine interface or other graphical user interface. (3) The RFPM automatically images the entire surface of the part or a predetermined portion (e.g., a predetermined percentage of the part sampled at a fixed location) (e.g., both 1 μm and larger 500 μm defects can be detected substantially simultaneously). (4) Once the required data is collected, the image is processed using computerized methods known in the relevant technical fields, e.g., using machine learning that is used to analyze and quantify defects. (5) Based on a predetermined set of inputs (e.g., the number of defects of a predetermined size or larger per unit area, the roughness level of a part or the whole of the scanned part, and other inputs and parameters described herein), a computer program determines whether the part passes or fails the inspection based on the programmed and analyzed defects.

[0039] The methods as described above can be implemented in various types of devices described in more detail below. The device includes, for example, a computer or microprocessor programmed in software, firmware, or as a hardware implementation with one or more aspects of the disclosed subject matter described above, or a dedicated processor such as 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. Individual operations of one or more methods are shown and described as separate operations, but one or more of the individual operations may be performed simultaneously and need not be performed in the order shown. In the exemplary configurations, 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 are described herein as including logic or a plurality of components, modules, or mechanisms. A module may comprise a software module (e.g., code embodied in a machine-readable medium or a 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 a group of processors) may be configured as a hardware module that operates by software (e.g., an application or a portion of an application) to perform particular 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 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 temporarily configured by software to perform a particular operation. 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 implement a hardware module mechanically in dedicated permanently configured circuitry or in temporarily configured circuitry (e.g., configured by software) may be made in view of cost and time.

[0044] Accordingly, it should be understood that the term "hardware module" encompasses 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 particular operations described herein. As used herein, "hardware-implemented module" refers to a hardware module. Considering embodiments in which a hardware module is temporarily configured (e.g., programmed), each hardware module need not be configured or instantiated within a time for any one instance. For example, when a hardware module includes a general-purpose processor configured by software to become a dedicated processor, the general-purpose processor may be configured as different dedicated processors (e.g., including different hardware modules) at different times. Thus, software may configure the processor, e.g., to configure a particular hardware module at one instance of time and different hardware modules at different instances of time.

[0045] A hardware module can provide information to other hardware modules and can also 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 can be achieved between two or more hardware modules by transmission of signals (e.g., via a suitable circuit or bus). In embodiments where multiple hardware modules are configured or instantiated at different times, communication between such hardware modules can be achieved, for example, by storage and retrieval of information within a memory structure accessible by 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. A further hardware module may then access the memory device, retrieve the stored output, and process it. A hardware module may also initiate communication with an input or output device and may operate on a resource (e.g., collect information).

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

[0047] Similarly, in the methods described herein, a processor may be implemented, at least in part, and a processor is an example of hardware. For example, at least some of the operations of the method may be performed by one or more processors or modules in which a processor is implemented. Further, one or more processors may operate to support the execution of relevant operations within a "cloud computing" environment or as "software as a service" (SaaS). For example, at least some of the operations may be performed by a group of computers (an example of a machine including a processor), and these operations are accessible through a network (e.g., the Internet) and one or more appropriate interfaces (e.g., an application program interface (API)).

[0048] The execution of certain operations may be allocated among one or more processors and may be performed not only within one machine but also deployed across multiple machines. In some embodiments, one or more processors or modules in which a processor is implemented may be located in one location (e.g., within a residential environment, an office environment, or a server farm). In other embodiments, one or more processors or modules in which a processor is implemented may be distributed across multiple locations.

[0049] As used herein, the term "or" may be construed inclusively or exclusively. Further, those skilled in the art will understand other embodiments by reading and understanding the described disclosure. Further, by reading and understanding the disclosure described herein, those skilled in the art will readily understand that all various combinations of the techniques and examples described herein can be applied in all various combinations.

[0050] Although the various embodiments have been described individually, these individual embodiments are not intended to be regarded as separate technologies or designs. As described above, the various parts may be related to each other, each may be used individually, or may be used in combination with other embodiments of the reflection Fourier ptychographic system described herein. For example, although various embodiments of methods, operations, and processes have been described, these methods, operations, and processes may be used individually or in various combinations.

[0051] Accordingly, as will be apparent to those skilled in the art upon reading and understanding the disclosure described herein, many changes and modifications are possible. In addition to those listed 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. Parts and features of some embodiments may be included in or replaced by other parts and features. Such changes and modifications are intended to be within the scope of the appended claims. Therefore, the present disclosure is limited only by the terms of the appended claims, together 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] A summary of the present disclosure is provided to enable the reader to quickly verify the technical disclosure. The summary is presented on the understanding that it is not to be used to interpret or limit the scope of the claims. Further, it can be seen from the foregoing "Detailed Description of the Invention" that various features may be grouped together in one embodiment for the purpose of rationalizing the present disclosure. The disclosed method should not be construed as limiting the scope of the claims. For this reason, the following claims are incorporated into the "Detailed Description of the Invention" as separate and independent embodiments for each claim.

[0053] The following numbered examples are specific embodiments of the disclosed subject matter. Example 1 Embodiments of the disclosed subject matter describe a method of operating a reflection mode Fourier ptychographic microscope (RFPM) to detect defects on the surface of a component. The method includes placing the component on a holding fixture of the RFPM and generating at least one illumination pattern from a plurality of component light sources configured to irradiate towards the surface, where the plurality of component light sources each have a plurality of individual light sources that operate individually, the at least one illumination pattern is selected from a plurality of patterns including a temporal pattern and a spatial pattern, collecting the redirected illumination from the surface by a sensor element, obtaining a differential phase measurement value by differential phase contrast (DPC) technique from the illumination collected by the sensor element, determining an angle between imaging axes from the surface to the sensor element, and determining at least a height characteristic of one or more defects on the surface.

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

[0055] Example 3 The method according to either of Example 1 or 2, further comprising raster scanning over an area of the surface by moving the component under the at least one generated illumination pattern.

[0056] Example 4 The method according to 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 component under the at least one generated illumination pattern.

[0057] Example 5 The method according to any one of the preceding examples, wherein the area is selected to be at least about 0.25 m of the surface 2 of the surface.

[0058] Example 6 A method according to 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 A method according to any one of the preceding examples, wherein the at least one illumination pattern is selected to illuminate the surface at a plurality of incident angles.

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

[0061] Example 9 A method according to any one of the preceding examples, wherein selecting the temporal pattern comprises selecting which of the plurality of individual light sources to activate and determining which of the remaining light sources of the selected plurality of individual light sources to activate within a time period.

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

[0063] Example 11 A method according to any one of the preceding examples, further comprising determining an angle from a perpendicular to the surface and an angle by which a midpoint of the at least one generated illumination pattern is offset from a normal.

[0064] Example 12 The method according to any one of the preceding examples, further comprising computationally combining at least one of the irradiations collected with a changed orientation from the surface, in order to increase the resolution of the detected defect and the wavelength of the light of the plurality of individual light sources with respect to the limit of the resolution of Rayleigh for a predetermined numerical aperture.

[0065] Example 13 The method according to any one of the preceding examples, further comprising selecting a condensing optical system for adjusting the focus of the collected irradiation to the sensor element from a predetermined numerical aperture.

[0066] Example 14 The method according to any one of the preceding examples, wherein the plurality of component light sources include an LED array.

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

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

[0069] Example 17 Embodiments of the disclosed subject matter describe a method of operating a reflection mode Fourier ptychographic microscope (RFPM). The method includes placing a non-biological component to be inspected on a fixture and selecting a program for executing and controlling one or more aspects of the RFPM, the aspects being selectable from aspects including a spatial pattern of a plurality of component light sources, a temporal pattern of the plurality of component light sources, a range of sizes of defects to be detected, an area of the component to be inspected, at least one height characteristic of one or more detected defects, and the number of images of the non-biological component to be recorded.

[0070] Example 18 The method according to Example 17, further comprising determining a roughness level of at least a part of the region of the component based on the recorded image.

[0071] Example 19 The method according to either Example 17 or Example 18, further comprising selecting a range of sizes of defects to be detected.

[0072] Example 20 The method according to any one of Examples 17 to 19, further comprising selecting a range of angles of irradiation of the light sources of the plurality of components towards the component.

[0073] Example 21 The method according to 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 The method according to any one of Examples 17 to 21, wherein the range of the size of the detected defect includes a range from about 50 nm to about 50 mm of the characteristic dimension of the detected defect.

[0075] Example 23 Embodiments of the disclosed subject matter describe a method of operating a reflectance-mode Fourier optics 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 configured to operate independently, the at least one illumination pattern 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 a region near the defect using a differential phase contrast (DPC) technique; determining an angle between an imaging axis from the surface to the sensor; and determining at least height characteristics of one or more defects on the surface.

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

[0077] Example 25 The method of 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 comprising 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 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 according to 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 for the remaining light sources of the selected plurality of individual light sources, determining which to activate within a time period.

[0081] Example 29 The method according to 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. A method for operating a reflection-mode Fourier ptychographic microscope (RFPM) to detect defects on the surface of a component, comprising: [[ID= ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ The method according to claim 1, wherein the area on the surface to be inspected is at least about 0.25 m of the surface ２ such that it is selected, the method. ​ ​ ​ ​ ​ ​ ​ ​ ​ Determining which of the remaining light sources among the selected plurality of individual light sources to activate within a time period A method comprising the above.

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

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

12. The method according to claim 1, further comprising computationally combining at least one of the irradiations collected from the surface with a changed orientation to increase the resolution of the detected defect and the wavelength of the light of the plurality of individual light sources with respect to the limit of the resolution of Rayleigh for a predetermined numerical aperture.

13. The method according to claim 1, further comprising selecting a condenser optical system for adjusting the focus of the collected irradiation to the sensor element from a predetermined numerical aperture.

14. The method according to claim 1, wherein the light source of the plurality of components comprises an LED array.

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

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

17. A method of operating a reflection-mode Fourier ptychographic microscope (RFPM), comprising Placing a non-biological component to be inspected on a fixture Selecting a program for executing and controlling one or more modes of the RFPM, The modes being selectable from modes including a spatial pattern of a plurality of component light sources, a temporal pattern of the plurality of component light sources, a range of sizes of defects to be detected, an area of the component to be inspected, at least one height characteristic of one or more detected defects, and the number of images of the non-biological component to be recorded.

18. The method according to claim 17, further comprising determining a roughness level of at least a part of the region of the component based on the recorded image.

19. The method according to claim 17, further comprising selecting a range of sizes of defects to be detected.

20. The method according to claim 17, further comprising selecting a range of angles of irradiation that the light sources of the plurality of components direct towards the component.

21. The method according to 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, plastic, and an oxidized surface.

22. The method according to claim 17, wherein the range of the size of the detected defect includes a range from about 50 nm to about 50 mm of the characteristic dimension of the detected defect.

23. A method of operating a reflection-mode Fourier ptychographic microscope (RFPM) for detecting defects on a surface of a component, generating at least one illumination pattern from a plurality of components of light sources configured to irradiate towards the surface, the plurality of components of light sources having a plurality of individual light sources, the plurality of components of light sources being configured to operate individually, the at least one illumination pattern being selected from a temporal pattern and a spatial pattern, using both bright-field imaging and dark-field imaging to sample the Fourier space of an image of the surface, collecting the irradiation redirected from the surface by a sensor, acquiring a phase differential measurement value from the redirected irradiation collected by the sensor in a region near the defect by differential phase contrast (DPC) technology, determining an angle between imaging axes from the surface to the sensor, determining at least a height characteristic of one or more defects on the surface comprising.

24. The method according to claim 23, wherein the characteristic dimension of the detected defect is a size of about 5 μm or more in a region of up to several square meters.

25. The method according to claim 23, wherein the component is a non-biological component.

26. The method according to 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. The method according to claim 23, wherein the spatial pattern is selected to illuminate the surface at a plurality of incident angles substantially simultaneously within the selected spatial pattern time.

28. The method according to claim 23, wherein selecting the temporal pattern comprises: selecting which of the plurality of individual light sources to activate; determining which of the remaining light sources of the selected individual light sources to activate over time relative to the selected individual light source of the plurality of individual light sources.

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

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