Photoluminescence for semiconductor qualification rate related applications

Abstract

The invention provides a method and a system for determining information of a sample. Certain embodiments relate to detecting photoluminescence for applications such as inspection and / or metrology of electro-optically active devices or advanced packaged devices. One embodiment of a system includes an illumination subsystem configured for directing light having one or more illumination wavelengths to a sample and a detection subsystem configured for detecting photoluminescence from the sample. The system also includes a computer subsystem configured for determining information of the sample from an output generated by the detection subsystem in response to the detected photoluminescence.

Description

DETAILED DESCRIPTION

[0001] The illumination and detection subsystems may be further configured as described in U.S. Patent Nos. 7,782,452, issued to Mehanian et al. on August 24, 2010, and 8,218,221, issued to Solarz on July 10, 2012, and U.S. Patent Application Publication No. 2009 / 0059215, published on March 5, 2009, to Mehanian et al., which are incorporated by reference as if fully set forth herein. The embodiments described herein may be further configured as described in these references.

[0002] The computer subsystem 46 may be coupled to the detector of the detection subsystem in any suitable manner (e.g., via one or more transmission media, which may include "wired" and / or "wireless" transmission media) so that the computer subsystem may receive output generated by the detector during illumination and possible scanning of the sample. The computer subsystem 46 may be configured to use the output of the detector to perform a number of functions further described herein.

[0003] Figure 1 The computer subsystem shown in (and other computer subsystems described herein) may also be referred to herein as a computer system. Each of the computer subsystems or systems described herein may be in various forms, including personal computer systems, image computers, large computer systems, workstations, network appliances, Internet appliances, or other devices. In general, the term "computer system" may be broadly defined to encompass any device having one or more processors that execute instructions from a memory medium. The computer subsystem or system may also include any suitable processor known in the art, such as a parallel processor. In addition, the computer subsystem or system may include a computer platform with high-speed processing and software as a stand-alone tool or a networked tool.

[0004] If the system includes more than one computer subsystem, the different computer subsystems may be coupled to each other so that images, data, information, instructions, etc. may be sent between the computer subsystems. For example, computer subsystem 46 may be coupled to computer system 102 via any suitable transmission medium (e.g., by a Figure 1 The transmission medium may include any suitable wired and / or wireless transmission medium known in the art. Two or more of such computer subsystems may also be effectively coupled by sharing a computer-readable storage medium (not shown).

[0005] As further described herein, the illumination and detection subsystems may be configured to generate outputs, such as images, of the sample in a variety of modes. In general, a "mode" is defined by the parameter values ​​of the illumination and detection subsystems used to generate the output of the sample. Thus, the modes may differ in the value of at least one of the parameters of the illumination and detection subsystems (in addition to the position on the sample at which the output is generated). For example, in the optical subsystem, different modes may use light of different wavelengths for illumination. The modes may differ in the illumination wavelength, as further described herein (e.g., by using different light sources, different spectral filters, etc. for different modes). In another example, different modes may use different illumination channels of the illumination subsystem. For example, as described above, the illumination subsystem may include more than one illumination channel. Thus, different illumination channels may be used for different modes. The modes may also or alternatively differ in one or more collection / detection parameters of the detection subsystem. The modes may differ in any one or more modifiable parameters of the system (e.g., illumination polarization, angle, wavelength, etc., detection polarization, angle, wavelength, etc.). The illumination and detection subsystems may be configured to scan a sample with different modes in the same scan or in different scans, for example, depending on the ability to scan a sample using multiple modes at the same time.

[0006] This article describes and Figure 1 The system shown in can be modified in one or more parameters to provide different capabilities depending on the application in which the system will be used. In one embodiment, the system is configured as an inspection system. In another embodiment, the system is configured as a metrology system. For example, if Figure 1 If the illumination and detection subsystem shown is used for metrology rather than inspection, then the illumination and detection subsystem can be configured to have a higher resolution. In another example, the system can be configured to perform different scanning methods for inspection and metrology. In other words, Figure 1 The embodiments of the system shown in describe various configurations of the system that can be adapted in a number of ways that will be apparent to those skilled in the art to produce a system with different capabilities that are more or less suitable for different applications.

[0007] In some embodiments where the system is configured as an inspection system, the inspection system is configured for macro inspection. In this manner, the systems described herein may be referred to as macro inspection tools. Macro inspection tools are particularly suitable for inspecting relatively noisy back-end-of-line (BEOL) layers, such as redistribution lines (RDL) and post-cutting applications. Macro inspection tools are defined herein as systems that are not necessarily diffraction limited and have a spatial resolution of about 200 nm to about 2.0 microns and above. This spatial resolution means that the size of the smallest defect that can be detected by such systems is greater than about 200 nm, which is much larger than the smallest defect that can be detected by the most advanced inspection tools on the market today, hence the name "macro" detector. Such systems tend to utilize longer wavelengths of light (e.g., about 500 nm to about 700 nm) compared to the most advanced inspection tools on the market today. These systems can be used when the DOI is relatively large.

[0008] As described above, the system may be configured for light to scan a physical version of the sample, thereby producing an output of the physical version of the sample. In this way, the system may be configured as a "real" system rather than a "virtual" system. However, Figure 1 The storage medium (not shown) and computer system 102 shown in the embodiment of the present invention may be configured as a "virtual" system. In particular, the storage medium and computer system may be configured as a "virtual" inspection system as described in commonly assigned U.S. Patent Nos. 8,126,255, issued on February 28, 2012 to Bhaskar et al. and 9,222,895, issued on December 29, 2015 to Duffy et al., both of which are incorporated by reference as if fully set forth herein. The embodiments described herein may be further configured as described in these patents.

[0009] The computer subsystem (e.g., computer subsystem 46 and / or computer system 102) is configured to determine information of the sample from the output generated by the detection subsystem in response to the detected PL. In general, the information determined by the computer subsystem based on the detection subsystem output can be any inspection and / or metrology-like information, such as the information described herein. In addition, the information determined for the sample based on the detection subsystem output can be a combination of multiple types of information described herein.

[0010] The computer subsystem can be configured for analyzing the PL response output and extracting device and / or defect information from the image. Important PL information for both individual devices or a sample area containing multiple devices includes, but is not limited to: (1) absolute emitted intensity; (2) intensity emitted into different wavelength bands; (3) relative changes in intensity emitted into different bands (i.e., color shift); (4) absolute or relative spectrum; (5) relative changes in intensity emitted into different cone angles; (6) intensity variation as a function of illumination light level (leakage effect); and (7) relative changes in intensity among different materials within the image.

[0011] In one such example, Figure 5 is a graph of the PL emission spectra of an abnormal micro-LED (i.e., a "dark pixel") and a normal micro-LED (i.e., a "normal pixel"). Figure 5 As shown by the plotted emission spectra in , the emission spectra of abnormal micro-LEDs and normal micro-LEDs are very different from each other, and the spectra can be used to disclose differences in materials and / or structures. In other words, by comparing the emission spectra of the micro-LEDs to each other, the differences between the micro-LEDs can be detected. In addition, comparing the emission spectrum of the micro-LEDs to the emission spectrum of a known "good" micro-LED (the "reference" spectrum) can be used to detect abnormal micro-LEDs. In either case, the difference between only a certain portion of the spectrum can be used for the applications described herein. For example, if there is a very large difference between the spectra at longer wavelengths, this is Figure 5 , then even if there are other differences between the spectra (e.g., a shift in the wavelength of peak emission intensity from 522.26 nm to 518.73 nm), the differences can also be used by the embodiments described herein. Therefore, by configuring the illumination and detection subsystem as described herein so that the illumination and detection subsystem can detect and generate outputs responsive to the emission spectra of the micro-LEDs, and by configuring the computer subsystem as described herein to compare the emission spectra to each other or to a known good reference, information about the micro-LEDs, such as which micro-LEDs are defective in material and / or structure, can be determined without having to electrically test the completed micro-LEDs.

[0012] The computer subsystem may also or alternatively be configured for analyzing a PL macro-overview image (MOI) of the entire sample or wafer. The computer subsystem may generate the MOI by stitching together multiple PL images based on various spatial relationships between the individual images. Important PL information for the entire wafer that may be generated by the computer subsystem includes, but is not limited to: (1) intensity variation across the wafer; (2) emission spectrum variation across the wafer; (3) emission cone angle variation across the wafer; (4) intensity variation among different wafers, especially among wafers from the same batch of epitaxial processes; (5) emission spectrum variation among different wafers, especially among wafers from the same batch of epitaxial processes; and (6) emission cone angle variation among different wafers, especially among wafers from the same batch of epitaxial processes.

[0013] In one embodiment, determining information includes detecting defects on the sample based on output generated by the detection subsystem in response to the detected PL. In this manner, the embodiments described herein may be configured for defect detection using PL techniques. For example, defect detection may be performed using any of the information described above. Defect detection may be performed using absolute values ​​or relative comparisons (e.g., device to device, region to region, etc.). In one such example, the computer subsystem may compare the absolute emitted intensity of each device to a threshold (or multiple thresholds), which may correspond to a range of absolute emitted intensities that are below (and possibly above) the nominal or designed absolute emitted intensity that is unacceptable for the device. If a device has an absolute emitted intensity that is below or above an acceptable level, then the device may be detected by the computer subsystem via such comparisons. Other algorithms and methods may also be used to determine which of the devices is defective (e.g., finding a device that has an abnormal absolute emitted intensity compared to other devices on the sample, etc.). In addition, the embodiments described herein may use any suitable defect detection algorithm known in the art, which may be applied to the PL response output (image or other), or may be modified to operate on the PL response output and generate information such as defect maps, heat maps, or any other suitable defect-related information of the sample.

[0014] In one such embodiment, the determination information includes determining the functional characteristics of the electro-optical action device. The functional characteristics may simply be an indication of whether the device is fully functional, that is, emitting a certain light and therefore appearing to be functional, or not emitting light at all and therefore appearing to be inoperative. However, the functional characteristics may be qualitative or quantitative in one or more additional or other ways. An example of these qualitative characteristics may be whether the device emits light of the correct wavelength. Quantitatively, these characteristics may include how different the wavelength of the emitted light is from the wavelength of the desired or expected light, the brightness difference between the emitted light and the expected light, and other quantitative measurements of the emitted light described further herein. Functional characteristics may be determined for any one or all of the devices examined by the embodiments described herein, and may be used to determine which of the defects in the device as further described herein.

[0015] Figure 6 and 7 The diagram illustrates how to detect color shift using the PL response output generated as described herein to detect color shift and / or changes among devices. In particular, Figure 6 An image of a sample 600 having a plurality of green light emitting devices 602 formed thereon is shown, which may be produced by the embodiments described herein. More specifically, Figure 6 The image shown in 604 may be produced by illuminating a green light emitting device with one or more UV illumination wavelengths and detecting the PL (and possibly other light) emitted by the device. The computer subsystem may then use such an image to perform defect detection, for example, by detecting any areas in the image that have emitted light of a wavelength different from that expected. Defect 604 shows some exemplary defects that may be detected for such a green light emitting device, which may include defects of various sizes and defects that emit yellow or light green light (e.g., green light outside of an expected or acceptable range of green light wavelengths). Thus, the embodiments described herein may detect defects of different characteristics on a green light emitting device by illuminating the device with UV light and detecting color shifts in the resulting detected PL.

[0016] Figure 7 An image of a sample 700 having a plurality of blue light emitting devices 702 formed thereon is shown, which may be produced by the embodiments described herein. More specifically, Figure 7The image shown in can be produced by illuminating a blue light emitting device with one or more UV illumination wavelengths and detecting the PL (and possibly other light) emitted by the device. The computer subsystem can then use such an image to perform defect detection, for example, by detecting any areas in the image that have emitted light of a different wavelength than expected, any areas of a different size, and / or any areas that have emitted light of a different wavelength than expected. For example, the majority of the shading in device 702 indicates a device that is determined to have a normal (or acceptable) size, brightness, and color. A device with the same lighter shading as device 704 is a device with normal size and color but abnormal brightness, that is, the device is defective simply because the device does not have the brightness it should. A device with the same darker shading as devices 706 and 708 is a device with normal size and color but brighter than it should be. A device with the same pattern fill as device 710 is a device with normal size and brightness but no color, for example, the device emits green light instead of blue light. Additionally, a device having the same pattern fill as device 712 is normal size but not color or brightness, for example, the device emits green light instead of blue light and is brighter than it should be.

[0017] The above-described functionality of the electro-optically active device may also be examined at more than one illumination wavelength band or wavelength. Figure 8 800 is a graph of PL emission spectra at different excitation wavelengths including 365 nm (at normal incidence), 385 nm, 405 nm (at normal incidence), and 415 nm (at normal incidence). The PL emission spectra can be normalized to the number of incident photons of the illumination light to make the comparison and contrast of the emission spectra more accurate. As can be seen in graph 800, the same electro-optical device can produce different PL emission spectra when illuminated with different excitation wavelengths. Each of these PL emission spectra (or one or more) can be generated by the embodiments described herein and used to determine information about the electro-optical device, such as functionality, detected defects, characteristics of defects, etc. In addition, such PL emission spectra indicate how the flexibility of the optics of the embodiments described herein can be used not only to detect multiple PL emission spectra from the same device but also to select from the various optics settings and configurations described herein to determine more or less information required for any one device.

[0018] In another such embodiment, determining the information further includes identifying one or more of the electro-optically active devices that are abnormal based on the characteristics of the functionality. For example, a novel feature of the embodiments described herein is that the system can use PL emissions to identify abnormal individual electro-optical devices or areas of a wafer containing abnormal devices. Figure 2Examples of images of micro LED wafers showing anomalous regions are shown. Specifically, image 200 is a standard (ie, non-PL) BF image of a micro LED wafer showing no features. In contrast, PL image 202 clearly shows anomalous regions that emit less or more than is acceptable.

[0019] Figure 3 The image 300 in is an image generated by magnifying one of the abnormal regions shown in the image 202. Each of the squares in such an image may be an individual micro LED. As shown in the image 300, when the computer subsystem magnifies the abnormal region in the PL image, the computer subsystem may determine that the abnormal region actually corresponds to multiple devices on the wafer. In this way, the computer subsystem may acquire some pixels in the image of the sample, and then expand the pixels to make the details clearer, which is useful for determining which pixels are actually emitting light.

[0020] Figure 4 Show how the computer subsystem generates a composite image from parts of multiple devices to enhance abnormal areas, thereby making the abnormal areas easier to detect and analyze. For example, the computer subsystem may use only those pixels in the original image 400 that are close to the center of each device (the active area 402 but not the edge area 404) to generate the composite image 406, and assign the average value to that device. Each pixel in the composite image represents a device. The darker areas are clearly visible. In another example, the computer subsystem may use only those pixels in the original image 408 that are close to the edge of each device (the edge area 404 but not the active area 402) to generate the composite image 410, and assign the average value to that device. Each pixel in the composite image 410 also represents a device, and the brighter areas are clearly visible. In this way, the computer subsystem can analyze the functionality of different parts of the devices described herein, in addition to how the functionality varies from device to device or from region to region on the sample.

[0021] In some such embodiments, the electro-optically active device is an unfinished device that cannot be electrically tested. For example, a significant advantage of the embodiments described herein is that they provide PL capabilities that can be used to detect subtle material changes between devices or across devices that affect PL emitted light. These changes may indicate local defects or process variations that might otherwise not be detected until electrical testing after the wafer is fully processed. By detecting these deviations early, the user can take corrective action quickly and save time and money. In addition, the embodiments described herein can use PL to sort or screen each micro-LED on the wafer at a processing volume worth producing before transferring the micro-LEDs in batches to the final display device, where the micro-LEDs can be electrically detected.

[0022] In one embodiment, the sample includes one or more packaging structures formed above, and the PL includes PL emitted by the one or more packaging structures. Therefore, an important new feature of the embodiments described herein is that it provides a system configured to excite and analyze the PL (or fluorescence) emission of advanced packaging devices. In recent years, advanced packaging technology has accelerated, making large-scale production of complex mobile devices and high-performance computing processors possible. As these devices are produced, they need to be inspected. Therefore, the inspection of advanced packaging structures is a growing and important application area. The embodiments described herein provide significant advantages for such applications because the embodiments can provide all of the advantages described herein for inspecting these packaging structures.

[0023] In one such embodiment, determining information includes determining whether any of one or more packaging structures is abnormal based on the detected PL. For example, a new feature of the embodiments described herein is that the system can use PL emissions to identify abnormal advanced packaged devices or areas of wafers containing abnormal devices. For example, some advanced semiconductor packaging materials (such as PI and PBO) emit fluorescence, while metals do not. Therefore, it is possible to use PL inspection to increase the capture rate of some difficult-to-find defects. In the embodiments described herein, the system can be configured for illumination wavelengths that can cause fluorescence from such materials, and for selectively detecting fluorescence from illuminated samples with such advanced packaging structures formed thereon. The computer subsystem can then detect defects on the sample based on the output in response to the fluorescence. For example, the detected fluorescence can be used to determine information about the structure and / or material that fluoresces, such as location, size, shape, etc. The computer subsystem can then apply a defect detection method to that information, for example, applying a threshold to the size of the fluorescing structure to determine whether the fluorescing structure is large enough to be considered a defect. Instead of applying the defect detection method to the information determined from the fluorescence response output, the defect detection method can be applied to the fluorescence output itself. Such defect detection may include applying one or more thresholds to characteristics of the fluorescence response output, which may include any of the PL response output characteristics described further herein.

[0024] In another embodiment, determining information includes determining metrology information of one or more structures formed on the sample based on output generated by the detection subsystem in response to the detected PL. For example, the computer subsystem may be configured to analyze the PL response output and extract critical dimension (CD) information from the image. CD information includes, but is not limited to: (1) microLED light extraction window size and shape; (2) microLED mesa size and shape; (3) microLED pitch; (4) RDL width and pitch; (5) via size; (6) photoresist opening size; and (7) overlay. The computer subsystem may be configured to determine such metrology information for the sample using any suitable method and / or algorithm known in the art.

[0025] In yet another embodiment, the illumination subsystem, detection subsystem, and computer subsystem are configured for simultaneously determining information and performing non-PL inspection of a sample. The term "non-PL inspection" as used herein is defined as an inspection performed by detecting light having a wavelength from a sample that is the same as the illumination wavelength and detecting defects on the sample based on an output in response to the detected light. For example, the system may be configured for performing any of the above-described PL-related functions simultaneously with conventional optical inspection. The system may be configured for performing non-PL or conventional inspection of a sample in any suitable manner known in the art.

[0026] In one such scenario, light from the sample having the same wavelength as the illumination and the PL from the sample can be detected separately, as further described herein. The computer subsystem can be configured to use the different outputs alone to determine information about the sample. For example, the computer subsystem can apply a first defect detection algorithm to the PL-responsive outputs, and can apply a second defect detection algorithm to the non-PL-responsive outputs. The first defect detection algorithm and the second defect detection algorithm can be the same or different in any one or more parameters, and the computer subsystem can apply the first defect detection algorithm and the second defect detection algorithm to the different outputs simultaneously or at different times.

[0027] In some examples, determining information by PL inspection and non-PL inspection may be performed using the same method or algorithm (e.g., such as when one defect detection method may be used to detect defects on a sample using both PL response output and non-PL response output). However, in many cases, the computer subsystem may also use different methods or algorithms to determine information using PL response signals and non-PL response signals because the information determined using PL and non-PL is likely to be different, even if this simply means using PL output and non-PL output to detect different types of defects on the sample.

[0028] The computer subsystem may also be configured for concurrently processing images (PL and / or non-PL) in a more traditional manner to detect traditional optical inspection defects such as bridges, openings, residues, over-etches, under-etches, dropped particles, etc. Thus, the PL capability may be an additional feature that may or may not be enabled depending on the application, and if not used does not negatively impact throughput or sensitivity.

[0029] Different inspections may generally be performed to detect different kinds of defects on the same sample, but in some cases different inspections may be performed to detect the same kind of defects on a sample. For example, conventional defect inspection may be used to detect as many defects as possible on a sample, which may include some defects that do not emit PL under any circumstances and some defects that may emit PL. PL inspection may also be performed on the sample (possibly simultaneously as described herein) for a number of reasons, including detecting defects on the sample that emit PL and that may have been missed by conventional inspection, and / or separating the detected defects into defects that emit PL and defects that do not emit PL. In this way, the results of PL inspection performed in conjunction with conventional inspection may be used as a class of additional defect attributes that may be used to separate different defect types from one another. This is also the case for conventional inspection defect attributes that are used as a supplement to PL-based defect attributes. In this way, PL inspection and non-PL inspection may be used as different modes in an inspection process that may be performed in the same manner as any other multi-mode inspection process currently performed.

[0030] In the same manner, the systems described herein may be configured for performing inspection with PL while also performing conventional metrology, or vice versa. In some cases, it may not make sense to perform inspection and metrology at the same time, as such processes typically require different measurement times, but if metrology can be performed substantially quickly (e.g., at the same or approximately the same throughput as inspection), then such a system configuration becomes more practical. Another possibility is to perform non-PL metrology on the same sample simultaneously or otherwise while performing PL metrology. For example, it may make sense to determine a first metrology characteristic of a patterned feature on a sample with non-PL metrology and to determine a second metrology characteristic of the same feature with PL metrology. In another example, the system may be configured to determine a metrology characteristic of a first patterned feature on a sample with non-PL metrology and to determine a metrology characteristic of a second patterned feature on the sample with PL metrology. In yet another example, the system may be configured to determine the same metrology characteristic of a patterned feature on a sample using a combination of PL response output and non-PL response output. In this manner, due to the flexibility of the systems described herein, the embodiments described herein may provide the ability to determine more metrology information for a sample that is superior (eg, more accurate, more detailed, etc.) than currently available metrology tools.

[0031] The computer subsystem may be configured to generate results for the sample, which may include any of the information described herein, such as information about any of the devices determined to be defective, any of the defect or metrology information described herein, a map of defect or metrology information across the sample, etc. Results for defective devices may include, but are not limited to, the location of the defective device, a detection score, information about the classification of the defective device (such as a class label or ID, etc.), or any such suitable information known in the art. Results for the sample may be generated by the computer subsystem in any suitable manner.

[0032] All embodiments described herein may be configured to store the result of one or more steps of the embodiment in a computer-readable storage medium. The result may include any one of the results described herein and may be stored in any manner known in the art. The result of a sample may have any suitable form or format, such as a standard file type. The storage medium may include any storage medium described herein or any other suitable storage medium known in the art. After the result has been stored, the result may be accessed in a storage medium and used by any one of the method or system embodiments described herein, formatted to be displayed to a user, used by another software module, method or system, etc., to perform one or more functions on another sample of a sample or the same type.

[0033] Such functions include, but are not limited to, altering a process, such as a manufacturing process or step that has been or is about to be performed on a sample, in a feedback or feedforward manner. For example, the computer subsystem may be configured to determine one or more changes to a process performed on a sample and / or a process to be performed on a sample based on a defective device. Changes to a process may include any suitable changes to one or more parameters of a process. The computer subsystem preferably determines those changes so that defective devices can be reduced or prevented on other samples on which a corrective process is performed, defective devices can be corrected or eliminated on a sample in another process performed on the sample, defective devices can be compensated for in another process performed on the sample, and so on. The computer subsystem may determine such changes in any suitable manner known in the art.

[0034] Those changes may then be sent to a semiconductor fabrication system (not shown) or a storage medium (not shown) accessible to both the computer subsystem and the semiconductor fabrication system. The semiconductor fabrication system may or may not be part of the system embodiments described herein. For example, the imaging hardware and / or computer subsystem described herein may be coupled to the semiconductor fabrication system, e.g., via one or more common elements, such as a housing, a power supply, a sample handling device or mechanism, etc. The semiconductor fabrication system may include any semiconductor fabrication system known in the art, such as a lithography tool, an etching tool, a chemical mechanical polishing (CMP) tool, a deposition tool, and the like.

[0035] Each of the embodiments of each of the systems described above may be combined together into a single embodiment.

[0036] Another embodiment is directed to a method for determining information of a sample. The method includes directing light having one or more illumination wavelengths to the sample, for example, with an illumination subsystem configured as described herein. The method also includes detecting PL from the sample, for example, with a detection subsystem configured as described herein. Additionally, the method includes determining information of the sample from an output responsive to the detected PL, for example, with a computer subsystem configured as described herein.

[0037] Each of the steps of the method may be performed as further described herein. The method may also include any other steps that may be performed by the systems, computer subsystems, and / or lighting and detection subsystems described herein. The computer subsystem, lighting subsystem, and detection subsystem (e.g., computer subsystem 46, respectively) Figure 1 The lighting subsystem shown in Figure 1 The detection subsystem shown in ( ) can be configured according to any of the embodiments described herein. In addition, the method described above can be performed by any of the system embodiments described herein.

[0038] Additional embodiments relate to a non-transitory computer readable medium storing program instructions executable on one or more computer systems for performing a computer-implemented method for determining information of a sample. One such embodiment is shown in Fig. 9 In particular, Fig. 9 , a non-transitory computer readable medium 900 includes program instructions 902 executable on a computer system 904. The computer-implemented method may include any of the steps of any of the methods described herein.

[0039] Program instructions 902 implementing methods such as those described herein may be stored on computer readable medium 900. The computer readable medium may be a storage medium such as a magnetic or optical disk, tape, or any other suitable non-transitory computer readable medium known in the art.

[0040] The program instructions may be implemented in any of a variety of ways, including process-based, component-based, and / or object-oriented techniques, among other techniques. For example, the program instructions may be implemented using ActiveX controls, C++ objects, JavaBeans, Microsoft Foundation Classes ("MFC", SSE (Streaming SIMD Extensions), or other techniques or methods.

[0041] Computer system 904 may be configured according to any of the embodiments described herein.

[0042] In view of this description, other modifications and alternative embodiments of various aspects of the present disclosure will be apparent to those skilled in the art. For example, methods and systems for determining information of a sample are provided. Therefore, this description should be considered as merely illustrative and is for the purpose of teaching those skilled in the art to implement the general manner of the present disclosure. It should be understood that the form of the present disclosure shown and described herein should be considered as the current preferred embodiment. As will be fully apparent to those skilled in the art after benefiting from this description of the present disclosure, elements and materials may replace the elements and materials illustrated and described herein, parts and processes may be reversed, and some features of the present disclosure may be utilized independently. Changes may be made to the elements described herein without departing from the spirit and scope of the present disclosure as described in the following claims.

[0043] The illumination and detection subsystems may be further configured as described in U.S. Patent Nos. 7,782,452, issued to Mehanian et al. on August 24, 2010, and 8,218,221, issued to Solarz on July 10, 2012, and U.S. Patent Application Publication No. 2009 / 0059215, published on March 5, 2009, to Mehanian et al., which are incorporated by reference as if fully set forth herein. The embodiments described herein may be further configured as described in these references.

[0044] The computer subsystem 46 may be coupled to the detector of the detection subsystem in any suitable manner (e.g., via one or more transmission media, which may include "wired" and / or "wireless" transmission media) so that the computer subsystem may receive output generated by the detector during illumination and possible scanning of the sample. The computer subsystem 46 may be configured to use the output of the detector to perform a number of functions further described herein.

[0045] Figure 1 The computer subsystem shown in (and other computer subsystems described herein) may also be referred to herein as a computer system. Each of the computer subsystems or systems described herein may be in various forms, including personal computer systems, image computers, large computer systems, workstations, network appliances, Internet appliances, or other devices. In general, the term "computer system" may be broadly defined to encompass any device having one or more processors that execute instructions from a memory medium. The computer subsystem or system may also include any suitable processor known in the art, such as a parallel processor. In addition, the computer subsystem or system may include a computer platform with high-speed processing and software as a stand-alone tool or a networked tool.

[0046] If the system includes more than one computer subsystem, the different computer subsystems may be coupled to each other so that images, data, information, instructions, etc. may be sent between the computer subsystems. For example, computer subsystem 46 may be coupled to computer system 102 via any suitable transmission medium (e.g., by a Figure 1 The transmission medium may include any suitable wired and / or wireless transmission medium known in the art. Two or more of such computer subsystems may also be effectively coupled by sharing a computer-readable storage medium (not shown).

[0047] As further described herein, the illumination and detection subsystems may be configured to generate outputs, such as images, of the sample in a variety of modes. In general, a "mode" is defined by the parameter values ​​of the illumination and detection subsystems used to generate the output of the sample. Thus, the modes may differ in the value of at least one of the parameters of the illumination and detection subsystems (in addition to the position on the sample at which the output is generated). For example, in the optical subsystem, different modes may use light of different wavelengths for illumination. The modes may differ in the illumination wavelength, as further described herein (e.g., by using different light sources, different spectral filters, etc. for different modes). In another example, different modes may use different illumination channels of the illumination subsystem. For example, as described above, the illumination subsystem may include more than one illumination channel. Thus, different illumination channels may be used for different modes. The modes may also or alternatively differ in one or more collection / detection parameters of the detection subsystem. The modes may differ in any one or more modifiable parameters of the system (e.g., illumination polarization, angle, wavelength, etc., detection polarization, angle, wavelength, etc.). The illumination and detection subsystems may be configured to scan a sample with different modes in the same scan or in different scans, for example, depending on the ability to scan a sample using multiple modes at the same time.

[0048] This article describes and Figure 1 The system shown in can be modified in one or more parameters to provide different capabilities depending on the application in which the system will be used. In one embodiment, the system is configured as an inspection system. In another embodiment, the system is configured as a metrology system. For example, if Figure 1 If the illumination and detection subsystem shown is used for metrology rather than inspection, then the illumination and detection subsystem can be configured to have a higher resolution. In another example, the system can be configured to perform different scanning methods for inspection and metrology. In other words, Figure 1 The embodiments of the system shown in describe various configurations of the system that can be adapted in a number of ways that will be apparent to those skilled in the art to produce a system with different capabilities that are more or less suitable for different applications.

[0049] In some embodiments where the system is configured as an inspection system, the inspection system is configured for macro inspection. In this manner, the systems described herein may be referred to as macro inspection tools. Macro inspection tools are particularly suitable for inspecting relatively noisy back-end-of-line (BEOL) layers, such as redistribution lines (RDL) and post-cutting applications. Macro inspection tools are defined herein as systems that are not necessarily diffraction limited and have a spatial resolution of about 200 nm to about 2.0 microns and above. This spatial resolution means that the size of the smallest defect that can be detected by such systems is greater than about 200 nm, which is much larger than the smallest defect that can be detected by the most advanced inspection tools on the market today, hence the name "macro" detector. Such systems tend to utilize longer wavelengths of light (e.g., about 500 nm to about 700 nm) compared to the most advanced inspection tools on the market today. These systems can be used when the DOI is relatively large.

[0050] As described above, the system may be configured for light to scan a physical version of the sample, thereby producing an output of the physical version of the sample. In this way, the system may be configured as a "real" system rather than a "virtual" system. However, Figure 1 The storage medium (not shown) and computer system 102 shown in the embodiment of the present invention may be configured as a "virtual" system. In particular, the storage medium and computer system may be configured as a "virtual" inspection system as described in commonly assigned U.S. Patent Nos. 8,126,255, issued on February 28, 2012 to Bhaskar et al. and 9,222,895, issued on December 29, 2015 to Duffy et al., both of which are incorporated by reference as if fully set forth herein. The embodiments described herein may be further configured as described in these patents.

[0051] The computer subsystem (e.g., computer subsystem 46 and / or computer system 102) is configured to determine information of the sample from the output generated by the detection subsystem in response to the detected PL. In general, the information determined by the computer subsystem based on the detection subsystem output can be any inspection and / or metrology-like information, such as the information described herein. In addition, the information determined for the sample based on the detection subsystem output can be a combination of multiple types of information described herein.

[0052] The computer subsystem can be configured for analyzing the PL response output and extracting device and / or defect information from the image. Important PL information for both individual devices or a sample area containing multiple devices includes, but is not limited to: (1) absolute emitted intensity; (2) intensity emitted into different wavelength bands; (3) relative changes in intensity emitted into different bands (i.e., color shift); (4) absolute or relative spectrum; (5) relative changes in intensity emitted into different cone angles; (6) intensity variation as a function of illumination light level (leakage effect); and (7) relative changes in intensity among different materials within the image.

[0053] In one such example, Figure 5 is a graph of the PL emission spectra of an abnormal micro-LED (i.e., a "dark pixel") and a normal micro-LED (i.e., a "normal pixel"). Figure 5 As shown by the plotted emission spectra in , the emission spectra of abnormal LEDs and normal LEDs are very different from each other, which spectra can be used to disclose differences in materials and / or structures. In other words, by comparing the emission spectra of micro-LEDs to each other, differences between micro-LEDs can be detected. In addition, comparing the emission spectrum of a micro-LED with the emission spectrum of a known "good" micro-LED (a "reference" spectrum) can be used to detect abnormal micro-LEDs. In either case, the difference between only a certain portion of the spectrum can be used for the applications described herein. For example, if there is a very large difference between the spectra at longer wavelengths, this is Figure 5 , then even if there are other differences between the spectra (e.g., a shift in the wavelength of peak emission intensity from 522.26 nm to 518.73 nm), the differences can also be used by the embodiments described herein. Therefore, by configuring the illumination and detection subsystem as described herein so that the illumination and detection subsystem can detect and generate outputs responsive to the emission spectra of the micro-LEDs, and by configuring the computer subsystem as described herein to compare the emission spectra to each other or to a known good reference, information about the micro-LEDs, such as which micro-LEDs are defective in material and / or structure, can be determined without having to electrically test the completed micro-LEDs.

[0054] The computer subsystem may also or alternatively be configured for analyzing a PL macro-overview image (MOI) of the entire sample or wafer. The computer subsystem may generate the MOI by stitching together multiple PL images based on various spatial relationships between the individual images. Important PL information for the entire wafer that may be generated by the computer subsystem includes, but is not limited to: (1) intensity variation across the wafer; (2) emission spectrum variation across the wafer; (3) emission cone angle variation across the wafer; (4) intensity variation among different wafers, especially among wafers from the same batch of epitaxial processes; (5) emission spectrum variation among different wafers, especially among wafers from the same batch of epitaxial processes; and (6) emission cone angle variation among different wafers, especially among wafers from the same batch of epitaxial processes.

[0055] In one embodiment, determining information includes detecting defects on the sample based on output generated by the detection subsystem in response to the detected PL. In this manner, the embodiments described herein may be configured for defect detection using PL techniques. For example, defect detection may be performed using any of the information described above. Defect detection may be performed using absolute values ​​or relative comparisons (e.g., device to device, region to region, etc.). In one such example, the computer subsystem may compare the absolute emitted intensity of each device to a threshold (or multiple thresholds), which may correspond to a range of absolute emitted intensities that are below (and possibly above) the nominal or designed absolute emitted intensity that is unacceptable for the device. If a device has an absolute emitted intensity that is below or above an acceptable level, then the device may be detected by the computer subsystem via such comparisons. Other algorithms and methods may also be used to determine which of the devices is defective (e.g., finding a device that has an abnormal absolute emitted intensity compared to other devices on the sample, etc.). In addition, the embodiments described herein may use any suitable defect detection algorithm known in the art, which may be applied to the PL response output (image or other), or may be modified to operate on the PL response output and generate information such as defect maps, heat maps, or any other suitable defect-related information of the sample.

[0056] In one such embodiment, the determination information includes determining the functional characteristics of the electro-optical action device. The functional characteristics may simply be an indication of whether the device is fully functional, that is, emitting a certain light and therefore appearing to be functional, or not emitting light at all and therefore appearing to be inoperative. However, the functional characteristics may be qualitative or quantitative in one or more additional or other ways. An example of these qualitative characteristics may be whether the device emits light of the correct wavelength. Quantitatively, these characteristics may include how different the wavelength of the emitted light is from the wavelength of the desired or expected light, the brightness difference between the emitted light and the expected light, and other quantitative measurements of the emitted light described further herein. Functional characteristics may be determined for any one or all of the devices examined by the embodiments described herein, and may be used to determine which of the defects in the device as further described herein.

[0057] Figure 6 and 7 The diagram illustrates how to detect color shift using the PL response output generated as described herein to detect color shift and / or changes among devices. In particular, Figure 6 An image of a sample 600 having a plurality of green light emitting devices 602 formed thereon is shown, which may be produced by the embodiments described herein. More specifically, Figure 6 The image shown in 604 may be produced by illuminating a green light emitting device with one or more UV illumination wavelengths and detecting the PL (and possibly other light) emitted by the device. The computer subsystem may then use such an image to perform defect detection, for example, by detecting any areas in the image that have emitted light of a wavelength different from that expected. Defect 604 shows some exemplary defects that may be detected for such a green light emitting device, which may include defects of various sizes and defects that emit yellow or light green light (e.g., green light outside of an expected or acceptable range of green light wavelengths). Thus, the embodiments described herein may detect defects of different characteristics on a green light emitting device by illuminating the device with UV light and detecting color shifts in the resulting detected PL.

[0058] Figure 7 An image of a sample 700 having a plurality of blue light emitting devices 702 formed thereon is shown, which may be produced by the embodiments described herein. More specifically, Figure 7The image shown in can be produced by illuminating a blue light emitting device with one or more UV illumination wavelengths and detecting the PL (and possibly other light) emitted by the device. The computer subsystem can then use such an image to perform defect detection, for example, by detecting any areas in the image that have emitted light of a different wavelength than expected, any areas of a different size, and / or any areas that have emitted light of a different wavelength than expected. For example, the majority of the shading in device 702 indicates a device that is determined to have a normal (or acceptable) size, brightness, and color. A device with the same lighter shading as device 704 is a device with normal size and color but abnormal brightness, that is, the device is defective simply because the device does not have the brightness it should. A device with the same darker shading as devices 706 and 708 is a device with normal size and color but brighter than it should be. A device with the same pattern fill as device 710 is a device with normal size and brightness but no color, for example, the device emits green light instead of blue light. Additionally, a device having the same pattern fill as device 712 is normal size but not color or brightness, for example, the device emits green light instead of blue light and is brighter than it should be.

[0059] The above-described functionality of the electro-optically active device may also be examined at more than one illumination wavelength band or wavelength. Figure 8 800 is a graph of PL emission spectra at different excitation wavelengths including 365 nm (at normal incidence), 385 nm, 405 nm (at normal incidence), and 415 nm (at normal incidence). The PL emission spectra can be normalized to the number of incident photons of the illumination light to make the comparison and contrast of the emission spectra more accurate. As can be seen in graph 800, the same electro-optical device can produce different PL emission spectra when illuminated with different excitation wavelengths. Each of these PL emission spectra (or one or more) can be generated by the embodiments described herein and used to determine information about the electro-optical device, such as functionality, detected defects, characteristics of defects, etc. In addition, such PL emission spectra indicate how the flexibility of the optics of the embodiments described herein can be used not only to detect multiple PL emission spectra from the same device but also to select from the various optics settings and configurations described herein to determine more or less information required for any one device.

[0060] In another such embodiment, determining the information further includes identifying one or more of the electro-optically active devices that are abnormal based on the characteristics of the functionality. For example, a novel feature of the embodiments described herein is that the system can use PL emissions to identify abnormal individual electro-optical devices or areas of a wafer containing abnormal devices. Figure 2Examples of images of micro LED wafers showing anomalous regions are shown. Specifically, image 200 is a standard (ie, non-PL) BF image of a micro LED wafer showing no features. In contrast, PL image 202 clearly shows anomalous regions that emit less or more than is acceptable.

[0061] Figure 3 The image 300 in is an image generated by magnifying one of the abnormal regions shown in the image 202. Each of the squares in such an image may be an individual micro LED. As shown in the image 300, when the computer subsystem magnifies the abnormal region in the PL image, the computer subsystem may determine that the abnormal region actually corresponds to multiple devices on the wafer. In this way, the computer subsystem may acquire some pixels in the image of the sample, and then expand the pixels to make the details clearer, which is useful for determining which pixels are actually emitting light.

[0062] Figure 4 Show how the computer subsystem generates a composite image from parts of multiple devices to enhance abnormal areas, thereby making the abnormal areas easier to detect and analyze. For example, the computer subsystem may use only those pixels in the original image 400 that are close to the center of each device (the active area 402 but not the edge area 404) to generate the composite image 406, and assign the average value to that device. Each pixel in the composite image represents a device. The darker areas are clearly visible. In another example, the computer subsystem may use only those pixels in the original image 408 that are close to the edge of each device (the edge area 404 but not the active area 402) to generate the composite image 410, and assign the average value to that device. Each pixel in the composite image 410 also represents a device, and the brighter areas are clearly visible. In this way, the computer subsystem can analyze the functionality of different parts of the devices described herein, in addition to how the functionality varies from device to device or from region to region on the sample.

[0063] In some such embodiments, the electro-optically active device is an unfinished device that cannot be electrically tested. For example, a significant advantage of the embodiments described herein is that they provide PL capabilities that can be used to detect subtle material changes between devices or across devices that affect PL emitted light. These changes may indicate local defects or process variations that might otherwise not be detected until electrical testing after the wafer is fully processed. By detecting these deviations early, the user can take corrective action quickly and save time and money. In addition, the embodiments described herein can use PL to sort or screen each micro-LED on the wafer at a processing volume worth producing before transferring the micro-LEDs in batches to the final display device, where the micro-LEDs can be electrically detected.

[0064] In one embodiment, the sample includes one or more packaging structures formed above, and the PL includes PL emitted by the one or more packaging structures. Therefore, an important new feature of the embodiments described herein is that it provides a system configured to excite and analyze the PL (or fluorescence) emission of advanced packaging devices. In recent years, advanced packaging technology has accelerated, making large-scale production of complex mobile devices and high-performance computing processors possible. As these devices are produced, they need to be inspected. Therefore, the inspection of advanced packaging structures is a growing and important application area. The embodiments described herein provide significant advantages for such applications because the embodiments can provide all of the advantages described herein for inspecting these packaging structures.

[0065] In one such embodiment, determining information includes determining whether any of one or more packaging structures is abnormal based on the detected PL. For example, a new feature of the embodiments described herein is that the system can use PL emissions to identify abnormal advanced packaged devices or areas of wafers containing abnormal devices. For example, some advanced semiconductor packaging materials (such as PI and PBO) emit fluorescence, while metals do not. Therefore, it is possible to use PL inspection to increase the capture rate of some difficult-to-find defects. In the embodiments described herein, the system can be configured for illumination wavelengths that can cause fluorescence from such materials, and for selectively detecting fluorescence from illuminated samples with such advanced packaging structures formed thereon. The computer subsystem can then detect defects on the sample based on the output in response to the fluorescence. For example, the detected fluorescence can be used to determine information about the structure and / or material that fluoresces, such as location, size, shape, etc. The computer subsystem can then apply a defect detection method to that information, for example, applying a threshold to the size of the fluorescing structure to determine whether the fluorescing structure is large enough to be considered a defect. Instead of applying the defect detection method to the information determined from the fluorescence response output, the defect detection method can be applied to the fluorescence output itself. Such defect detection may include applying one or more thresholds to characteristics of the fluorescence response output, which may include any of the PL response output characteristics described further herein.

[0066] In another embodiment, determining information includes determining metrology information of one or more structures formed on the sample based on output generated by the detection subsystem in response to the detected PL. For example, the computer subsystem may be configured to analyze the PL response output and extract critical dimension (CD) information from the image. CD information includes, but is not limited to: (1) microLED light extraction window size and shape; (2) microLED mesa size and shape; (3) microLED pitch; (4) RDL width and pitch; (5) via size; (6) photoresist opening size; and (7) overlay. The computer subsystem may be configured to determine such metrology information for the sample using any suitable method and / or algorithm known in the art.

[0067] In yet another embodiment, the illumination subsystem, detection subsystem, and computer subsystem are configured for simultaneously determining information and performing non-PL inspection of a sample. The term "non-PL inspection" as used herein is defined as an inspection performed by detecting light having a wavelength from a sample that is the same as the illumination wavelength and detecting defects on the sample based on an output in response to the detected light. For example, the system may be configured for performing any of the above-described PL-related functions simultaneously with conventional optical inspection. The system may be configured for performing non-PL or conventional inspection of a sample in any suitable manner known in the art.

[0068] In one such scenario, light from the sample having the same wavelength as the illumination and the PL from the sample can be detected separately, as further described herein. The computer subsystem can be configured to use the different outputs alone to determine information about the sample. For example, the computer subsystem can apply a first defect detection algorithm to the PL-responsive outputs, and can apply a second defect detection algorithm to the non-PL-responsive outputs. The first defect detection algorithm and the second defect detection algorithm can be the same or different in any one or more parameters, and the computer subsystem can apply the first defect detection algorithm and the second defect detection algorithm to the different outputs simultaneously or at different times.

[0069] In some examples, determining information by PL inspection and non-PL inspection may be performed using the same method or algorithm (e.g., such as when one defect detection method may be used to detect defects on samples having both PL response outputs and non-PL response outputs). However, in many cases, the computer subsystem may also use different methods or algorithms to determine information with PL response signals and non-PL response signals because the information determined with PL and non-PL is likely to be different, even if this means simply detecting different types of defects on samples having PL outputs and non-PL outputs.

[0070] The computer subsystem may also be configured for concurrently processing images (PL and / or non-PL) in a more traditional manner to detect traditional optical inspection defects such as bridges, openings, residues, over-etches, under-etches, dropped particles, etc. Thus, the PL capability may be an additional feature that may or may not be enabled depending on the application, and if not used does not negatively impact throughput or sensitivity.

[0071] Different inspections may generally be performed to detect different kinds of defects on the same sample, but in some cases different inspections may be performed to detect the same kind of defects on a sample. For example, conventional defect inspection may be used to detect as many defects as possible on a sample, which may include some defects that do not emit PL under any circumstances and some defects that may emit PL. PL inspection may also be performed on the sample (possibly simultaneously as described herein) for a number of reasons, including detecting defects on the sample that emit PL and that may have been missed by conventional inspection, and / or separating the detected defects into defects that emit PL and defects that do not emit PL. In this way, the results of PL inspection performed in conjunction with conventional inspection may be used as a class of additional defect attributes that may be used to separate different defect types from one another. This is also the case for conventional inspection defect attributes that are used as a supplement to PL-based defect attributes. In this way, PL inspection and non-PL inspection may be used as different modes in an inspection process that may be performed in the same manner as any other multi-mode inspection process currently performed.

[0072] In the same manner, the systems described herein may be configured for performing inspection with PL while also performing conventional metrology, or vice versa. In some cases, it may not make sense to perform inspection and metrology at the same time, as such processes typically require different measurement times, but if metrology can be performed substantially quickly (e.g., at the same or approximately the same throughput as inspection), then such a system configuration becomes more practical. Another possibility is to perform non-PL metrology on the same sample simultaneously or otherwise while performing PL metrology. For example, it may make sense to determine a first metrology characteristic of a patterned feature on a sample with non-PL metrology and to determine a second metrology characteristic of the same feature with PL metrology. In another example, the system may be configured to determine a metrology characteristic of a first patterned feature on a sample with non-PL metrology and to determine a metrology characteristic of a second patterned feature on the sample with PL metrology. In yet another example, the system may be configured to determine the same metrology characteristic of a patterned feature on a sample using a combination of PL response output and non-PL response output. In this manner, due to the flexibility of the systems described herein, the embodiments described herein may provide the ability to determine more metrology information for a sample that is superior (eg, more accurate, more detailed, etc.) than currently available metrology tools.

[0073] The computer subsystem may be configured to generate results for the sample, which may include any of the information described herein, such as information about any of the devices determined to be defective, any of the defect or metrology information described herein, a map of defect or metrology information across the sample, etc. Results for defective devices may include, but are not limited to, the location of the defective device, a detection score, information about the classification of the defective device (such as a class label or ID, etc.), or any such suitable information known in the art. Results for the sample may be generated by the computer subsystem in any suitable manner.

[0074] All embodiments described herein may be configured to store the result of one or more steps of the embodiment in a computer-readable storage medium. The result may include any one of the results described herein and may be stored in any manner known in the art. The result of a sample may have any suitable form or format, such as a standard file type. The storage medium may include any storage medium described herein or any other suitable storage medium known in the art. After the result has been stored, the result may be accessed in a storage medium and used by any one of the method or system embodiments described herein, formatted to be displayed to a user, used by another software module, method or system, etc., to perform one or more functions on another sample of a sample or the same type.

[0075] Such functions include, but are not limited to, altering a process, such as a manufacturing process or step that has been or is about to be performed on a sample, in a feedback or feedforward manner. For example, the computer subsystem may be configured to determine one or more changes to a process performed on a sample and / or a process to be performed on a sample based on a defective device. Changes to a process may include any suitable changes to one or more parameters of a process. The computer subsystem preferably determines those changes so that defective devices can be reduced or prevented on other samples on which a corrective process is performed, defective devices can be corrected or eliminated on a sample in another process performed on the sample, defective devices can be compensated for in another process performed on the sample, and so on. The computer subsystem may determine such changes in any suitable manner known in the art.

[0076] Those changes may then be sent to a semiconductor fabrication system (not shown) or a storage medium (not shown) accessible to both the computer subsystem and the semiconductor fabrication system. The semiconductor fabrication system may or may not be part of the system embodiments described herein. For example, the imaging hardware and / or computer subsystem described herein may be coupled to the semiconductor fabrication system, e.g., via one or more common elements, such as a housing, a power supply, a sample handling device or mechanism, etc. The semiconductor fabrication system may include any semiconductor fabrication system known in the art, such as a lithography tool, an etching tool, a chemical mechanical polishing (CMP) tool, a deposition tool, and the like.

[0077] Each of the embodiments of each of the systems described above may be combined together into a single embodiment.

[0078] Another embodiment is directed to a method for determining information of a sample. The method includes directing light having one or more illumination wavelengths to the sample, for example, with an illumination subsystem configured as described herein. The method also includes detecting PL from the sample, for example, with a detection subsystem configured as described herein. Additionally, the method includes determining information of the sample from an output responsive to the detected PL, for example, with a computer subsystem configured as described herein.

[0079] Each of the steps of the method may be performed as further described herein. The method may also include any other steps that may be performed by the systems, computer subsystems, and / or lighting and detection subsystems described herein. The computer subsystem, lighting subsystem, and detection subsystem (e.g., computer subsystem 46, respectively) Figure 1 The lighting subsystem shown in Figure 1 The detection subsystem shown in ( ) can be configured according to any of the embodiments described herein. In addition, the method described above can be performed by any of the system embodiments described herein.

[0080] Additional embodiments relate to a non-transitory computer readable medium storing program instructions executable on one or more computer systems for performing a computer-implemented method for determining information of a sample. One such embodiment is shown in Fig. 9 In particular, Fig. 9 , a non-transitory computer readable medium 900 includes program instructions 902 executable on a computer system 904. The computer-implemented method may include any of the steps of any of the methods described herein.

[0081] Program instructions 902 implementing methods such as those described herein may be stored on computer readable medium 900. The computer readable medium may be a storage medium such as a magnetic or optical disk, tape, or any other suitable non-transitory computer readable medium known in the art.

[0082] The program instructions may be implemented in any of a variety of ways, including process-based, component-based, and / or object-oriented techniques, among other techniques. For example, the program instructions may be implemented using ActiveX controls, C++ objects, JavaBeans, Microsoft Foundation Classes ("MFC", SSE (Streaming SIMD Extensions), or other techniques or methods.

[0083] Computer system 904 may be configured according to any of the embodiments described herein.

[0084] In view of this description, other modifications and alternative embodiments of various aspects of the present disclosure will be apparent to those skilled in the art. For example, methods and systems for determining information of a sample are provided. Therefore, this description should be considered as merely illustrative and is for the purpose of teaching those skilled in the art to implement the general manner of the present disclosure. It should be understood that the form of the present disclosure shown and described herein should be considered as the current preferred embodiment. As will be fully apparent to those skilled in the art after benefiting from this description of the present disclosure, elements and materials may replace the elements and materials illustrated and described herein, parts and processes may be reversed, and some features of the present disclosure may be utilized independently. Changes may be made to the elements described herein without departing from the spirit and scope of the present disclosure as described in the following claims.

Claims

1. A system configured to determine information of a sample, comprising: an illumination subsystem configured for directing light having one or more illumination wavelengths to the sample; a detection subsystem configured to detect photoluminescence from the sample; and A computer subsystem is configured for determining information of the sample from output produced by the detection subsystem in response to the detected photoluminescence.

2. The system of claim 1, wherein the one or more illumination wavelengths include red, green, and blue wavelengths.

3. The system of claim 1, wherein the one or more illumination wavelengths include red, green, blue, and ultraviolet wavelengths.

4. The system of claim 1, wherein the sample comprises an electro-optically active device, and wherein the one or more illumination wavelengths are selected to be absorbed by the electro-optically active device, thereby causing the electro-optically active device to emit the photoluminescence.

5. The system of claim 4, wherein determining the information comprises determining a characteristic of functionality of the electro-optically active device.

6. The system of claim 5, wherein determining the information further comprises identifying one or more of the electro-optically active devices that are abnormal based on the characteristics of the functionality.

7. The system of claim 4, wherein the electro-optically active device is an unfinished device that cannot be electrically tested.

8. The system of claim 4, wherein the electro-optically active device comprises a micro-light emitting diode, and wherein the photoluminescence comprises photoluminescence emitted by the micro-light emitting diode.

9. The system of claim 1, wherein the photoluminescence does not include fluorescence.

10. The system of claim 1, wherein the photoluminescence comprises fluorescence.

11. The system of claim 1, wherein the sample comprises one or more package structures formed thereon, and wherein the photoluminescence comprises photoluminescence emitted by the one or more package structures.

12. The system of claim 11, wherein determining the information comprises determining whether any of the one or more package structures is abnormal based on the detected photoluminescence.

13. The system of claim 1 , wherein the illumination subsystem and the detection subsystem are further configured for both brightfield imaging and darkfield imaging, and wherein the computer subsystem is further configured for selecting only the brightfield imaging, only the darkfield imaging, or both the brightfield imaging and the darkfield imaging in order to determine the information based on one or more characteristics of the sample.

14. The system of claim 1 , wherein the illumination subsystem is further configured for directing light having a plurality of illumination bands to the sample, wherein the detection subsystem is further configured for detecting light having a plurality of detection bands from the sample, and wherein the computer subsystem is further configured for selecting one or more of the plurality of illumination bands and one or more of the plurality of detection bands in order to determine the information based on one or more characteristics of the sample.

15. The system of claim 1, wherein determining the information comprises detecting defects on the sample based on the output produced by the detection subsystem in response to the detected photoluminescence.

16. The system of claim 1, wherein determining the information comprises determining metrology information of one or more structures formed on the sample based on the output produced by the detection subsystem in response to the detected photoluminescence.

17. The system of claim 1, further comprising a scanning subsystem configured for causing the light from the illumination subsystem to scan the sample while detecting the photoluminescence from the sample in an in-line inspection throughput.

18. The system of claim 1, wherein the illumination subsystem, detection subsystem, and computer subsystem are further configured for simultaneously determining the information and performing a non-photoluminescent inspection of the sample.

19. The system of claim 1, wherein the detection subsystem comprises a long pass filter positioned in front of a detector configured for detecting the photoluminescence.

20. A method for determining information of a sample, comprising: directing light having one or more illumination wavelengths toward the sample; detecting photoluminescence from the sample; and Information about the sample is determined from an output responsive to the detected photoluminescence.

Images