Multi-element super-resolution optical inspection system

Abstract

A method is disclosed. The method may include the step of generating a first optical image of a sample using a first inspection subsystem. The first optical image may be generated when a first set of photoluminescent markers emits photoluminescent illumination during a first time interval. The method may include the step of generating additional optical images using an additional inspection subsystem. The additional optical images may be generated when additional photoluminescent markers emit photoluminescent illumination during an additional time interval. The method may include the step of generating a cumulative optical image based on the first optical image and the additional optical images. The method may include the step of determining the locations of the photoluminescent markers based on the cumulative optical image. The method may include the step of determining a pattern of the sample based on the determined locations of the photoluminescent markers.

Description

Technology Field

[0001] Cross-reference regarding related applications

[0002] This application claims the benefit of 35 USC §119(e) of U.S. Provisional Patent Application Serial No. 63 / 319,821 filed March 15, 2022, the entire contents of which are incorporated herein by reference.

[0003] Technology field

[0004] The present invention generally relates to defect detection, and in particular to a multi-element super resolution optical inspection system. Background Technology

[0005] As the demand for integrated circuits with unprecedentedly small device features continues to rise, the need to improve defect detection mechanisms is increasing. Electron beam inspection systems generate high-resolution images but cannot scan entire samples within a reasonable timeframe and at an acceptable throughput rate. Consequently, current inspection systems often rely on the principle of light scattering to generate defect signals. However, as defect sizes continue to shrink, optical mode optimization has become insufficient. It is crucial to find the optimal optical mode to maximize the unique scattering signature of the defect.

[0006] Therefore, it would be advantageous to provide a system and method to address the shortcomings of the approach identified above. means of solving the problem

[0007] A multi-element super-resolution inspection system according to one or more embodiments of the present disclosure is disclosed. In an embodiment, the system comprises an array of inspection subsystems. In an embodiment, each inspection subsystem comprises one or more illumination sources configured to illuminate a sample positioned on a stage with one or more illumination beams, the sample comprises at least a first material and at least a second material, the first material being different from the second material, and the sample comprises a plurality of photoluminescent markers configured to selectively bind to one of the first material and the second material to enhance a feature of interest on the sample. In an embodiment, each inspection subsystem comprises a set of optical elements, and at least one optical element among the set of optical elements is configured to independently and selectively direct one or more illumination beams from one or more illumination sources to a plurality of photoluminescent markers of the sample so that at least one of the plurality of photoluminescent markers emits photoluminescent illumination. In an embodiment, each inspection subsystem comprises one or more detectors configured to detect photoluminescent illumination emitted by at least one of a plurality of photoluminescent markers selectively bound to one of the first material and the second material of the sample, and a set of optical elements configured to selectively direct photoluminescent illumination from said at least one of the plurality of photoluminescent markers of one of the first material and the second material of the sample to said one or more detectors.In an embodiment, a first inspection subsystem among an array of inspection subsystems is configured to generate a first illumination beam in a first time interval and direct the first illumination beam toward a first part of a sample including a first set of photoluminescent markers so that the first set of photoluminescent markers emits photoluminescent illumination in the first time interval, and the first inspection subsystem among the array of inspection subsystems is configured to image the first part of the sample in the first time interval to generate a first optical image when the first set of photoluminescent markers is emitting photoluminescent illumination. In an embodiment, one or more additional inspection subsystems among an array of inspection subsystems are configured to generate an additional set of illumination beams in one or more additional time intervals and to direct the additional set of illumination beams toward one or more additional parts of a sample including one or more additional sets of photoluminescent markers so that one or more additional sets of photoluminescent markers emit photoluminescent illumination in one or more additional time intervals, and one or more additional inspection subsystems among an array of inspection subsystems are configured to generate one or more additional optical images by imaging one or more additional parts of a sample in one or more additional time intervals when said one or more additional sets of photoluminescent markers are emitting photoluminescent illumination. In an embodiment, the system further includes a controller communicably coupled to an array of inspection subsystems.In an embodiment, the controller comprises one or more processors, and the one or more processors are configured to execute a program instruction to generate a first optical image of a sample using a first inspection subsystem among an inspection subsystem array, wherein the first optical image is generated when a first set of photoluminescent markers among a plurality of photoluminescent markers emits photoluminescent illumination in a first time interval; generate one or more additional optical images using one or more additional inspection subsystems among an inspection subsystem array, wherein the one or more additional optical images are generated when one or more additional sets of photoluminescent markers among a plurality of photoluminescent markers emit photoluminescent illumination in one or more additional time intervals; generate an accumulated optical image based on the received first optical image and one or more additional received optical images; determine the positions of a plurality of photoluminescent markers based on the accumulated optical image; and determine the pattern of the sample based on the determined positions of the plurality of photoluminescent markers.

[0008] A method for super-resolution inspection according to one or more embodiments of the present method is disclosed. In an embodiment, the method comprises the step of generating a first optical image of a sample using a first inspection subsystem among an array of inspection subsystems, wherein the sample comprises at least a first material and at least a second material, wherein the first material is different from the second material, and the sample comprises a plurality of photoluminescent markers configured to selectively bind to one of the first material and the second material to enhance a feature of interest on the sample, and the first optical image is generated when a first set of photoluminescent markers among the plurality of photoluminescent markers emits photoluminescent illumination in a first time interval. In an embodiment, the method comprises the step of generating one or more additional optical images using one or more additional inspection subsystems among an array of inspection subsystems, wherein one or more additional optical images are generated when one or more additional sets of photoluminescent markers among the plurality of photoluminescent markers emit photoluminescent illumination in one or more additional time intervals. In an embodiment, the method comprises the step of generating a cumulative optical image based on the received first optical image and one or more additional received optical images. In an embodiment, the method includes the step of determining the positions of a plurality of photoluminescent markers based on an accumulated optical image. In an embodiment, the method includes the step of determining the pattern of a sample based on the determined positions of the plurality of photoluminescent markers.

[0009] A system according to one or more embodiments of the present disclosure is disclosed. In an embodiment, the system comprises a controller including one or more processors, and the one or more processors cause the one or more processors to generate a first optical image of a sample using a first inspection subsystem among an array of inspection subsystems, wherein the sample comprises at least a first material and at least a second material, wherein the first material is different from the second material, and the sample comprises a plurality of photoluminescent markers configured to selectively bind to one of the first material and the second material to enhance a feature of interest on the sample, and the first optical image is generated when a first set of photoluminescent markers among the plurality of photoluminescent markers emits photoluminescent illumination in a first time interval -; generate one or more additional optical images using one or more additional inspection subsystems among an array of inspection subsystems, wherein one or more additional optical images are generated when one or more additional sets of photoluminescent markers among the plurality of photoluminescent markers emit photoluminescent illumination in one or more additional time intervals -; generate an accumulated optical image based on the received first optical image and one or more additional received optical images; It is configured to execute a program command that determines the positions of multiple photoluminescent markers based on an accumulated optical image and determines the pattern of a sample based on the determined positions of the multiple photoluminescent markers.

[0010] A multi-element super-resolution inspection system according to one or more embodiments of the present disclosure is disclosed. In an embodiment, the system comprises an array of inspection subsystems. In an embodiment, each inspection subsystem comprises one or more light sources configured to illuminate a sample positioned on a stage with one or more light beams, the sample comprises at least a first material and at least a second material, the first material being different from the second material, and the sample comprises a plurality of photoluminescent markers configured to selectively bind to one of the first material and the second material to enhance a feature of interest on the sample. In an embodiment, each inspection subsystem comprises a set of optical elements, and at least one optical element among the set of optical elements is configured to independently and selectively direct one or more light beams from one or more light sources to a plurality of photoluminescent markers of the sample so that at least one of the plurality of photoluminescent markers emits photoluminescent light. In an embodiment, each inspection subsystem comprises one or more detectors configured to detect photoluminescent illumination emitted by at least one of a plurality of photoluminescent markers selectively bound to one of the first material and the second material of the sample, and a set of optical elements is configured to selectively direct photoluminescent illumination from at least one of the plurality of photoluminescent markers of one of the first material and the second material of the sample to one or more detectors.In an embodiment, a first inspection subsystem among an array of inspection subsystems is configured to generate a first illumination beam in a first time interval and direct the first illumination beam toward a first part of a sample including a first set of photoluminescent markers so that the first set of photoluminescent markers emits photoluminescent illumination in the first time interval, and the first inspection subsystem among the array of inspection subsystems is configured to image the first part of the sample in the first time interval to generate a first optical image when the first set of photoluminescent markers is emitting photoluminescent illumination. In an embodiment, one or more additional inspection subsystems among an array of inspection subsystems are configured to generate an additional set of illumination beams in one or more additional time intervals and to direct the additional set of illumination beams toward one or more additional parts of a sample including one or more additional sets of photoluminescent markers so that one or more additional sets of photoluminescent markers emit photoluminescent illumination in one or more additional time intervals, and one or more additional inspection subsystems among an array of inspection subsystems are configured to generate one or more additional optical images by imaging one or more additional parts of a sample in one or more additional time intervals when one or more additional sets of photoluminescent markers are emitting photoluminescent illumination.

[0011] It should be understood that the foregoing general description and the following detailed description are merely illustrative and descriptive and are not intended to limit the claimed invention. The accompanying drawings, included in and constituting a part of the specification, serve to illustrate embodiments of the invention and, together with the general description, explain the principles of the invention. Brief explanation of the drawing

[0012] The various advantages of the present disclosure can be better understood by those skilled in the art by referring to the accompanying drawings. FIG. 1a illustrates a simplified schematic diagram of a multi-element super-resolution optical inspection system according to one or more embodiments of the present disclosure. FIG. 1b illustrates a planar conceptual diagram of a multi-element super-resolution optical inspection system according to one or more embodiments of the present disclosure. FIG. 1c illustrates a simplified schematic diagram of an inspection subsystem of a multi-element super-resolution optical inspection system according to one or more embodiments of the present disclosure. FIG. 2a illustrates a schematic diagram of a patterned sample according to one or more embodiments of the present disclosure. FIG. 2b illustrates a schematic diagram of a patterned sample comprising a plurality of photoluminescent markers according to one or more embodiments of the present disclosure. FIG. 2c illustrates a simplified schematic diagram of a method for determining the position of a plurality of photoluminescent markers on a sample according to one or more embodiments of the present disclosure. FIG. 3 illustrates a flowchart depicting a method for detecting one or more defects using a photoluminescent material according to one or more embodiments of the present disclosure. FIG. 4a illustrates an active marker on a sample in a plurality of time intervals according to one or more embodiments of the present disclosure. FIG. 4b illustrates a plurality of optical images generated in each of a plurality of time intervals according to one or more embodiments of the present disclosure, along with corresponding peak positions of a point spread function. FIG. 5 illustrates an accumulated position map in a plurality of time intervals according to one or more embodiments of the present disclosure. Specific details for implementing the invention

[0013] The present disclosure has been illustrated and described in particular with respect to specific embodiments and specific features thereof. The embodiments described herein are to be considered illustrative rather than limiting. It will be readily apparent to those skilled in the art that various changes and modifications in form and detail may be made without departing from the spirit and scope of the present disclosure. We will now refer in detail to the subject matter of the disclosed material as illustrated in the accompanying drawings.

[0014] Embodiments of the present disclosure relate to a system and method for multi-element super-resolution optical inspection. In particular, embodiments of the present disclosure relate to a system and method for multi-element super-resolution optical inspection using selective markers on a sample, wherein the selective markers have blinking characteristics (e.g., switching between on / off states). For example, the selective marker may include a photoluminescent marker configured to selectively attach to at least one of a first material and a second material of the sample, wherein one or more illumination sources may be configured to selectively excite the photoluminescent marker so that the selected photoluminescent marker emits photoluminescent radiation. Thus, since the signal characteristics of the photoluminescent markers are known prior to inspection, optical mode optimization may be reduced.

[0015] Furthermore, embodiments of the present disclosure relate to a system and method for multi-element super-resolution optical inspection using an array of inspection subsystems, wherein individual inspection subsystems may be individually controllable. For example, the array of inspection subsystems may be configured to image a sample containing selective markers at different time intervals to generate multiple optical images at individual time intervals. For example, individual inspection subsystems may be configured to image individual parts of a sample individually to generate individual optical images for individual parts of a sample. In this regard, an accumulated optical image may be generated based on individual optical images from individual inspection subsystems, and the locations of the selective markers may be determined based on the accumulated optical image. Thus, the locations of the selective markers can be used to determine the pattern of the sample using the accumulated optical image. Since the locations of the photoluminescent markers yield nanometer-scale pattern information that enables the system to analyze sample features, this enables high-sensitivity defect detection. Furthermore, photoluminescent markers can bind to defects to reveal their locations. Unlike traditional optical inspection, which relies on signal-to-noise ratio (SNR) differentiation for defect detection, super-resolution systems discover the presence of defects by detecting the positions of photoluminescent markers associated with the defects. Additionally, since the system enables parallel image acquisition during sample scanning, the sample throughput is significantly higher than that of electron beam inspection (EBI) systems.

[0016] FIG. 1a is a simplified schematic diagram illustrating a multi-element super-resolution optical inspection system (100) according to one or more embodiments of the present disclosure. FIG. 1b is a conceptual diagram illustrating a plan view of an array of inspection subsystems (101a-101d) of the multi-element super-resolution optical inspection system (100) positioned over individual parts of a sample (102) according to one or more embodiments of the present disclosure.

[0017] In an embodiment, the system (100) includes an array of inspection subsystems (101a-101d) positioned on a sample (102). For example, as shown in FIG. 1a, the system (100) may include a first inspection subsystem (101a), a second inspection subsystem (101b), a third inspection subsystem (101c), and up to N inspection subsystems (101d).

[0018] In an embodiment, the system (100) includes a stage assembly (104) suitable for fixing and positioning a sample (102). The stage assembly (104) may include any sample stage architecture known in the art. For example, the stage assembly (104) may include a linear stage configured to translate the sample (102) along one of the x-axis and y-axis. As another example, the stage assembly (104) may include a rotary stage.

[0019] Referring to FIG. 1b, each inspection subsystem (101a-101d) of an array of inspection subsystems (101a-101d) may be positioned over individual parts of the sample (102). For example, individual inspection subsystems (101a-101d) may be configured to scan (or image) individual parts of the sample (102) based on individual scan fields (103) of individual inspection subsystems (101a-101d). For example, a stage assembly (104) may be configured to adjust the position of the sample (102) based on individual scan fields (103) of individual inspection subsystems (101a-101d) to generate a plurality of images (105a-105d).

[0020] In one example, the first inspection subsystem (101a) may include a first scan field and be configured to image a first portion of the sample (102) to generate a first image (105a) of the sample (102). In another example, the second inspection subsystem (101b) may include a second scan field and be configured to image a second portion of the sample (102) to generate a second image (105b) of the sample (102). In yet another example, the third inspection subsystem (101c) may include a third scan field and be configured to image a third portion of the sample (102) to generate a third image (105c) of the sample. It is noted that the system (100) may include up to N inspection subsystems (101d) configured to image up to N parts of a sample to generate up to N images (105d) of the sample. It is noted that the system (100) may include any configuration of inspection subsystems (101) (e.g., any number, any arrangement, etc.). FIGS. 1a and 1b are provided for illustrative purposes only and should not be construed as limiting the scope of the disclosure.

[0021] In an embodiment, the system (100) includes a controller (106) that is communicably coupled to an array of inspection subsystems (101a-101d). The controller (106) may include one or more processors (108) configured to execute a set of program instructions maintained in a memory medium (110) (memory (110)).

[0022] In an embodiment, one or more processors (108) are configured to execute a program instruction configured to determine the positions of a plurality of photoluminescent markers based on a generated cumulative position map for a sample so that the pattern and defects of the sample can be resolved, as further discussed herein.

[0023] In an embodiment, one or more processors (108) are configured to execute program instructions configured to instruct one or more processors (108) to identify one or more defects (204) on a sample (102) based on collected photoluminescent radiation (120). For example, one or more processors (108) may be configured to generate a cumulative position map based on a plurality of optical images generated from individual inspection subsystems (101a-101d). For example, one or more processors (108) may be configured to generate a cumulative position map by receiving a plurality of optical inspection images (105a-105d) from individual inspection subsystems (101a-101d). In this regard, one or more processors (108) may be configured to determine the locations of photoluminescent markers based on the generated cumulative map so that patterns and defects on the sample can be analyzed.

[0024] FIG. 1c is a simplified schematic diagram illustrating an inspection subsystem (101a) of a multi-element super-resolution optical inspection system (100) according to one or more embodiments of the present disclosure. For the purposes of the present disclosure, "inspection subsystem (101)", "subsystem (101)" and variations thereof may be considered equivalent unless otherwise stated herein.

[0025] In an embodiment, one or more of the inspection subsystems (101a-101d) may be implemented by the inspection subsystem (101) illustrated in FIG. 1c. In an embodiment, one or more of the inspection subsystems (101a-101d) may include one or more light sources (112) configured to generate one or more light beams (114). The one or more light sources (112) may include any type of light source suitable for exciting a photoluminescent marker on a sample surface.

[0026] In an embodiment, one or more light sources (112) include one or more narrowband light sources. For example, one or more light sources (112) may include one or more fiber light sources, but are not limited thereto. For example, one or more fiber light sources may include one or more light-emitting diodes (LEDs), one or more laser diodes, etc., but are not limited thereto. A laser diode may be configured to generate any type of laser radiation, such as (but not limited to) infrared radiation, visible light radiation, and / or ultraviolet (UV) radiation.

[0027] In an embodiment, one or more light sources (112) include one or more broadband light sources. For example, one or more light sources (112) may include one or more broadband lamps configured to generate broadband light (e.g., white light) of a certain range of wavelengths, but are not limited thereto. For example, one or more light sources (112) may include one or more broadband plasma (BBP) light, but are not limited thereto.

[0028] FIGS. 2a and 2b are conceptual diagrams illustrating patterned samples (102) according to one or more embodiments of the present disclosure. It is noted herein that the patterned samples (102) illustrated in FIGS. 2a and 2b are shown at high magnification for illustrative purposes.

[0029] In an embodiment, the sample (102) may include a patterned sample (102). For example, the sample (102) may include a patterned substrate (102). In one example, the sample (102) may include a patterned wafer (104). Additionally, the sample (102) may include an integrated circuit (IC) device (102). In another example, the sample (102) may include a patterned meta lens.

[0030] The pattern of the sample (102) may be formed from at least a first material (200) and a second material (202), wherein the first material (200) is different from the second material (202). For example, as shown in FIGS. 2a and 2b, the sample (102) may include a grid pattern formed from the interlacing of the first material (200) and the second material (202).

[0031] Although FIGS. 2a and 2b illustrate that the patterned sample (102) is formed from a first material (200) and a second material (202), it is noted that the patterned sample (102) can be formed from any number of materials. For example, the patterned sample (102) can be formed from at least a first material, a second material, a third material... up to a Nth material.

[0032] In the examples, the first material or the second material may include porous carbon-doped organosilicon (pSiCOH), copper (Cu), cobalt (Co), ruthenium (Ru), tungsten (W), aluminum (Al), silicon (Si), polycrystalline silicon, titanium nitride (TiN), silicon nitride (Si3N4), etc., but is not required to include.

[0033] Referring to FIG. 2b, the sample (102) may include a defect (204) positioned between a portion of the first material (200) and a portion of the second material (202). For example, the sample (102) may include a bridge defect positioned between a portion of the first material (200) and a portion of the second material (202). For example, the bridge defect may be a 10 nm bridge defect, wherein the critical dimension of the line and space array is 10 nm.

[0034] Referring to FIG. 2b, in an embodiment, the sample (102) includes a plurality of photoluminescent markers (206) configured to selectively bind to either a first material (200) or a second material (202) to enhance a feature of interest on the sample (102). For example, the plurality of photoluminescent markers (206) are configured to preferentially attach to a targeted material (e.g., the first material (200) or the second material (202)), thereby enabling the targeted material to have enhanced photon emission based on the properties of the photoluminescent markers (206). In one example, the plurality of photoluminescent markers (206) are configured to preferentially attach to the first material (200) rather than the second material (202), so that only the signal from the first material (200) can be enhanced. In another example, a plurality of photoluminescent markers (206) are configured to be attached preferentially to the second material (202) rather than the first material (200), so that only the signal from the second material (202) can be enhanced.

[0035] For the purposes of the present disclosure, it is noted that the feature of interest may include, but is not limited to, a defect of interest, a pattern of interest, or a material of interest. For example, a plurality of photoluminescent markers (206) may be configured to selectively bind to one of the first material (200) and the second material (202) to reinforce the defect of interest. As another example, a plurality of photoluminescent markers (206) may be configured to selectively bind to one of the first material (200) and the second material (202) to reinforce the pattern of interest. As yet another example, a plurality of photoluminescent markers (206) may be configured to selectively bind to one of the first material (200) and the second material (202) to reinforce the material of interest.

[0036] A plurality of photoluminescent markers (206) may include one or more photoluminescent molecules, including (but not limited to) one or more organic dyes, one or more quantum dots, one or more carbon dots, one or more transition metals, one or more conjugated polymers, one or more phosphorescent nanoparticles, etc.

[0037] In the inspection subsystem (101), a plurality of photoluminescent markers (or photoluminescent molecules) may include any type of photoluminescent particle suitable for generating photoluminescence. For example, one or more photoluminescent tags may include one or more fluorescent tags. For example, a signal molecule may include one or more hydrophobic fluorophores, one or more hydrophilic fluorophores, etc. It is noted that the description of fluorescence in this disclosure is for illustrative purposes rather than to be limiting, and that detecting defects using any type of photoluminescent material is within the scope of this disclosure.

[0038] Photoluminescent markers are discussed in detail in U.S. Regular Patent Application No. 17 / 887,078, filed on August 12, 2022, with the title of the invention 'SYSTEM AND METHOD FOR FEATURE SIGNAL ENHANCEMENT USING SELECTIVELY BOUNDED PHOTOLUMINESCENT Material', and in U.S. Regular Patent Application No. 18 / 101,573, filed on January 25, 2023, all of which are incorporated by reference in their entirety.

[0039] Referring again to FIG. 1c, in the embodiment, each inspection subsystem (101) includes a set of optical elements (116) configured to direct one or more illumination beams (114) toward a sample (102).

[0040] In an embodiment, a set of optical elements (116) of individual inspection subsystems (101a-101d) is configured to cause a plurality of photoluminescent markers (206) to selectively emit photoluminescent illumination in a predetermined time interval within a point spread function (PSF). For example, a set of optical elements of an array of inspection subsystems (101a-101d) may emit one or more illumination beams (114) in a plurality of time intervals (t1, t2, t2, t1). n It is configured to independently and selectively direct to a plurality of photoluminescent markers (206) of a sample (102) so that the plurality of photoluminescent markers (206) selectively emit photoluminescent radiation. For example, individual inspection subsystems (101a-101a) may be configured to selectively cause a subset of the plurality of photoluminescent markers (206) to emit light at a specified time within a point diffusion function (PSF).

[0041] In this regard, as illustrated in FIG. 2c, in the first time interval (t1), a first subset (206a) of photoluminescent markers may be configured to emit light. Additionally, as illustrated in FIG. 2c, in the second time interval (t2), a second subset (206b) of photoluminescent markers may be configured to emit light. As further discussed herein, to achieve super-resolution, individual time intervals (t n Summation of subsets of photoluminescent markers over ) can be used. For example, super resolution can be achieved by selectively controlling multiple photoluminescent markers over multiple time intervals.

[0042] In an embodiment, each inspection subsystem (101) includes one or more collecting optical devices (118) configured to collect photoluminescent radiation (120) emitted from a sample (102) and direct said photoluminescent radiation (120) toward one or more detectors (122). It is noted herein that one or more collecting optical devices (118) may be oriented at any position relative to the sample (102).

[0043] In an embodiment, each inspection subsystem (101) includes one or more optical elements (124) configured to condition photoluminescent radiation (120) before detection by one or more detectors (122).

[0044] It is noted herein that a set of one or more optical elements (116), one or more collecting optical devices (118), and one or more optical elements (124) may be referred to as a single set of optical elements. It is further noted that a set of one or more optical elements (116), one or more collecting optical devices (118), and one or more optical elements (124) may share common optical elements. For example, a single objective lens may be configured to direct illumination toward a sample as well as to collect light returned from the sample.

[0045] Additionally, it is noted that the set of optical elements (116, 118, 124) may include any type of optical element. For example, the set of optical elements may include, but is not limited to, one or more diffractive optical elements (DOE), one or more lenses, one or more mirrors, etc. In one example, if the set of optical elements includes one or more lenses, the one or more lenses may include one or more micro-lenses (or miniature lenses). In another example, if the set of optical elements includes one or more mirrors, the one or more mirrors may include one or more micro-electromechanical (MEM) systems.

[0046] Micro-mirror arrays (MMAs) are discussed in detail in U.S. Patent No. 9,104,120, issued on August 11, 2015, titled 'Structured Illumination for Contrast Enhancement in Overlay Metrology', the entire contents of which are incorporated by reference. Micro-lenses are described in U.S. Patent No. 7,180,658, issued on February 20, 2007, titled 'High Performance Catadioptric Imaging System'; U.S. Patent No. 7,639,419, issued on December 29, 2009, titled 'Inspection System using Small Catadioptric Objective'; and U.S. Patent No. 7,646,533, issued on January 12, 2010, titled 'Small Ultra-High Catadioptric Objective'. The invention is described in detail in U.S. Patent No. 7,869,121, issued on January 11, 2011, titled 'Small Ultra-High NA Catadioptric Objective Using Aspheric Surfaces', all of which are incorporated by reference in their entirety.

[0047] Additionally, it is mentioned herein that one or more detectors (122) may include any optical detector known in the field suitable for measuring light emitted from the sample (102). For example, one or more detectors (122) may include, but are not limited to, a Charge-Coupled Device (CCD) detector, a Complementary Metal-Oxide-Semiconductor (CMOS) detector, an electron-multiplying CCD detector, an electron-multiplying CCD (EMCCD), etc.

[0048] In an embodiment, each inspection subsystem (101a-101d) may include a controller communicably coupled to one or more detectors (122). The controller may include one or more processors configured to execute a set of program instructions maintained in a memory medium (memory).

[0049] In an embodiment, a controller may be communicably coupled to a stage assembly (104) to associate photoluminescent radiation (120) from a plurality of photoluminescent markers with specific locations on a sample (102) associated with one or more defects. For example, one or more processors of the controller may be configured to adjust the position of the stage assembly (104) in a plurality of time intervals to generate a plurality of optical images (105a-105d) of the sample (102) in individual time intervals. As further discussed herein, for example, one or more processors may be configured to adjust the position of the stage assembly (104) so ​​that individual inspection subsystems (101a-101d) may be configured to image individual parts of the sample (102) when individual photoluminescent markers are emitting light (e.g., when the markers are "on"). For the purposes of the present disclosure, the term “active marker” and variations thereof include photoluminescent markers that emit light at a specified time (e.g., illuminated by one or more illumination beams (114)).

[0050] FIG. 3 illustrates a flowchart depicting a method (300) for detecting defects using a photoluminescent material selectively attached to a target material of a sample according to one or more embodiments of the present disclosure. FIG. 4a illustrates active markers on a sample (102) in a plurality of time intervals according to one or more embodiments of the present disclosure. FIG. 4b illustrates a plurality of optical images generated in each of the plurality of time intervals, along with corresponding peak positions of point diffusion functions, according to one or more embodiments of the present disclosure.

[0051] In step (302), a first optical image may be generated. For example, the first inspection subsystem (101a) may generate a first optical image when a first subset of photoluminescent markers is emitting photoluminescence. For example, a first set of light sources of the first inspection subsystem (101a) may be configured to generate a first set of light beams (114) at t1, and a first set of optical elements may be configured to independently and selectively direct the first set of light beams (114) toward a first set of photoluminescent markers of the sample (102). Additionally, a first set of detectors (122) of the first inspection subsystem (101a) may be configured to detect photoluminescent light (120) from a first subset of photoluminescent markers (206) at t1, thereby generating a first optical image based on the emitted photoluminescent light.

[0052] Referring to FIG. 4a, in the first time interval (t1), a first subset (206a) of photoluminescent markers may be configured to emit light.

[0053] Referring to FIG. 4b, the first optical image (408) can be generated by the first inspection subsystem (101a) in the first time interval (t1) when the first subset (400) of active markers is emitting light.

[0054] In step (304), one or more additional optical images may be generated. For example, one or more additional inspection subsystems (101b-101d) may generate one or more additional optical images when one or more additional subsets of photoluminescent markers are emitting photoluminescence. For example, one or more additional subsets of light sources of one or more additional inspection subsystems (101b-101d) may generate one or more additional time intervals (t2-t n It may be configured to generate one or more additional subsets of an illumination beam (114) in ), and one or more additional subsets of optical elements may be configured to independently and selectively direct one or more additional illumination beams (114) to one or more additional subsets of photoluminescent markers of the sample (102). Additionally, one or more additional subsets of detectors (122) of one or more additional inspection subsystems (101b-101d) may be configured to provide one or more additional time intervals (t2-t n It is configured to detect photoluminescent radiation (120) from one or more additional subsets of photoluminescent markers (206) in ) and can generate one or more additional optical images based on the emitted photoluminescent light.

[0055] Referring to FIG. 4a, a second subset (402) of markers may be configured to emit light in a second time interval (t2), a third subset (404) of markers may be configured to emit light in a third time interval (t3), and a fourth subset (406) of markers may be configured to emit light in a fourth time interval (t4).

[0056] Referring to FIG. 4b, in a non-limiting example, a second optical image (410) may be generated by the second inspection subsystem (101b) in a second time interval (t2) when a second subset (402) of active markers is emitting light. In another example, as illustrated in FIG. 4b, a third optical image (412) may be generated by the third inspection subsystem (101c) in a third time interval (t3) when a third subset (404) of active markers is emitting light. In yet another example, as illustrated in FIG. 4b, a fourth optical image (414) may be generated by the fourth inspection subsystem (101d) in a fourth time interval (t4) when a fourth subset (406) of active markers is emitting light.

[0057] In an embodiment, a plurality of optical images (408-414) are configured to identify corresponding peak positions of the PSFs of the active markers (400-406). For example, a first set (416) of peak positions of the PSFs of a first subset (400) of the active markers is identified in a first optical image (408) taken at t1. As another example, a second set (418) of peak positions of the PSFs of a second subset (402) of the active markers is identified in a second optical image (410) taken at t2. As yet another example, a third set (420) of peak positions of the PSFs of a third subset (404) of the active markers is identified in a third optical image (412) taken at t3. As yet another example, a fourth set (422) of peak positions of the PSFs of a fourth subset (406) of the active markers is identified in a fourth optical image (414) taken at t4. It is noted that the density of a subset of photoluminescent markers can be controlled so that the peaks of the PSF provide accurate markers. Additionally, since the positions of all markers can be determined over time, the cumulative marker location map can yield a super-resolution image.

[0058] FIGS. 4a and 4b illustrate a specific configuration of active markers, but it is noted that the system (100) may include any number of markers and may be configured to activate markers of any configuration over any number of time intervals. FIGS. 4a and 4b are provided for illustrative purposes only and should not be construed as limiting the scope of the disclosure.

[0059] In step (306), cumulative position maps may be generated based on a first optical image and one or more additional optical images. For example, the controller (106) may be configured to generate multiple cumulative position maps at multiple time stamps to determine the pattern of the sample (102).

[0060] Referring to FIG. 5, the first time stamp (t x A first position map (500) in ) can be generated, and a second time stamp (t y A second position map (502) in ) can be generated, and a third time stamp (t z A third position map (504) at ) can be generated. As shown in FIG. 5, at time t x In the position map (500) generated through, fractional marker locations can be determined. In contrast, the third time stamp (t z After that, the pattern of the sample becomes more clearly visible, so that the bridge defect (204) can be visually identified from the pattern of the sample (102).

[0061] In step (308), the positions of a plurality of photoluminescent markers are determined based on the generated cumulative position map. For example, as previously discussed in this specification, since the active markers are well separated, the controller (106) may be configured to determine the positions of the markers based on the PSF peaks (such as the PSF peaks (416-422) shown in FIG. 4b) of a plurality of optical images (such as the images (406-414) shown in FIG. 4b). For example, the estimated marker positions may be determined based on the PSF peaks of each optical image.

[0062] In step (310), the pattern of the sample is determined based on the cumulative position map of a plurality of position maps. For example, the controller (106) may be configured to determine the pattern of the sample based on the cumulative position map. For example, after a predetermined time step, the pattern of the sample (102) may be identifiable.

[0063] In step (312), a defect on the sample is detected based on a determined pattern of the sample. For example, the controller (106) may be configured to determine the location of the defect on the sample based on the determined pattern of the sample. For example, after a predetermined time step, the defect may be visually identifiable from the pattern of the sample (102).

[0064] Although embodiments of the present disclosure relate to inspection systems, it is considered that a patterned wafer comprising an optionally bound photoluminescent material may be used with any characterization system including (but not limited to) an optical measurement system (e.g., an image-based measurement system), etc.

[0065] It is also considered that each of the embodiments of the method described above may include any other step(s) of any other method(s) described herein. Additionally, each of the embodiments of the method described above may be performed by any of the systems described herein.

[0066] Referring again to FIG. 1, one or more processors (108) of the controller (106) may include any processing elements known in the art. In this sense, one or more processors (108) may include any microprocessor-type device configured to execute algorithms and / or instructions. In one embodiment, one or more processors (108) may be a desktop computer, a mainframe computer system, a workstation, an image computer, a parallel processor, or any other computer system (e.g., a networked computer) configured to execute a program configured to operate the system (100) as described throughout this disclosure. It is also acknowledged that the term “processor” may be broadly defined to encompass any device having one or more processing elements that execute program instructions from a non-transient memory medium (110). Accordingly, the above description should not be interpreted as a limitation to the invention and is merely illustrative.

[0067] The memory medium (110) may include any storage medium known in the art suitable for storing program instructions executable by one or more associated processors (108). As a non-limiting example, the memory medium (110) may include a non-transient memory medium. As an additional non-limiting example, the memory medium (110) may include, but is not limited to, read-only memory, random access memory, magnetic or optical memory devices (e.g., disks), magnetic tape, solid state drives, etc. Additionally, it is noted that the memory (110) may be housed in a common controller housing together with one or more processors (108). In an alternative embodiment, the memory (110) may be located remotely from the physical location of one or more processors (108) and the controller (106). For example, one or more processors (108) of the controller (106) may access remote memory (e.g., a server) accessible via a network (e.g., the Internet, an intranet, etc.).

[0068] Those skilled in the art will recognize that the components, actions, devices, objects, and accompanying discussions described herein are used as examples for conceptual clarity and that various configuration modifications are considered. Consequently, as used herein, the specific examples and accompanying discussions presented are intended to represent their more general classes. Generally, the use of any specific example is intended to represent that class, and the exclusion of specific components, actions, devices, and objects should not be construed as limiting.

[0069] With respect to the use of substantially any plural and / or singular terms in this specification, those skilled in the art may switch from plural to singular and / or singular to plural as appropriate to the context and / or application. Various singular / plural substitutions are not explicitly presented in this specification for the sake of clarity.

[0070] The subject matter described herein illustrates different components that are sometimes included within or connected to other components. It should be understood that the architectures described are merely examples and that many other architectures may actually be implemented to achieve the same functionality. In a conceptual sense, any arrangement of components to achieve the same functionality is effectively "associated" so that the desired functionality is achieved. Accordingly, any two components combined in this specification to achieve a specific functionality may be viewed as "associated" with each other so that the desired functionality is achieved, regardless of the architectures or intermediate components. Likewise, any two components so associated may be viewed as "connected" or "combined" with each other to achieve the desired functionality, and any two components so associated may be viewed as "combinable" with each other to achieve the desired functionality. Specific examples of what is combinable include, but are not limited to, physically combinable and / or physically interacting components and / or wirelessly interacting and / or wirelessly interacting components and / or logically interacting and / or logically interacting components.

[0071] Furthermore, it should be understood that the present invention is defined by the appended claims. Those skilled in the art will understand that the terms used in this specification, particularly in the appended claims (e.g., the body of the appended claims), are generally intended to be "open" terms (e.g., the term "comprising" should be interpreted as "comprising but not limited thereto," the term "comprising" as "at least comprising," the term "comprising" as "comprising but not limited thereto," etc.). Additionally, those skilled in the art will understand that if a specific number of introduced claim recitations are intended, such intent will be explicitly stated in the claims, and where such statement is absent, such intent does not exist. For example, for the sake of understanding, the following appended claims may include the use of the introductory phrases "at least one" and "one or more" to introduce claim recitations. However, the use of such wording must not be interpreted as implying that the introduction of a claim description by the indefinite article "a" or "an" limits any particular claim containing such introduced claim description to an invention containing only one such description, even when the same claim contains the indefinite article such as "one or more" or "at least one" and "a" or "an" (e.g., "a" and / or "an" should generally be interpreted as "at least one" or "one or more"); the same applies to the use of the definite article to introduce a claim description. Furthermore, even if a specific number of introduced claim descriptions are explicitly stated, those skilled in the art will recognize that such statement should generally be interpreted to mean at least the number stated (e.g., the simple statement "two recitations" without other modifiers generally means at least two recitations, or two or more recitations).In addition, where a convention similar to "at least one of A, B, and C, etc." is used, such configuration is generally intended in the sense that a person skilled in the art understands that convention (e.g., "a system having at least one of A, B, and C" includes, but is not limited to, systems having A alone, B alone, C alone, A and B together, A and C together, B and C together, and / or A, B, and C together, etc.). Where a convention similar to "at least one of A, B, or C, etc." is used, such configuration is generally intended in the sense that a person skilled in the art understands that convention (e.g., "a system having at least one of A, B, or C" includes, but is not limited to, systems having A alone, B alone, C alone, A and B together, A and C together, B and C together, and / or A, B, and C together, etc.). Those skilled in the art will also understand that almost any separable word and / or phrase presenting two or more alternative terms, whether in the description, claims, or drawings, should be understood to imply the possibility of including one of the terms, either of the terms, or both of the terms. For example, the phrase "A or B" will be understood to imply the possibility of "A" or "B" or "A and B".

[0072] It is believed that the present disclosure and the many advantages associated therewith will be understood from the foregoing description, and it will be apparent that various modifications to the form, configuration, and arrangement of the components may be made without departing from the subject matter of the disclosure or without sacrificing all its important advantages. The described forms are for illustrative purposes only, and it is the intent of the following claims to encompass and include such modifications. Furthermore, it should be understood that the present invention is defined by the appended claims.

Claims

Claim 1 As a multi-element super-resolution inspection system, an array of inspection subsystems; each inspection subsystem comprises one or more light sources configured to illuminate a sample positioned on a stage with one or more illumination beams; the sample comprises at least a first material and at least a second material, wherein the first material is different from the second material; and the sample comprises a plurality of photoluminescent markers configured to selectively bind to one of the first material and the second material to enhance a feature of interest on the sample; a set of optical elements; at least one optical element among the set of optical elements is configured to independently and selectively direct the one or more illumination beams from the one or more light sources to the plurality of photoluminescent markers of the sample so that at least one of the plurality of photoluminescent markers emits photoluminescent illumination.and one or more detectors configured to detect photoluminescent illumination emitted by at least one photoluminescent marker among a plurality of photoluminescent markers selectively bound to one of the first material and the second material of the sample—the set of optical elements is configured to selectively direct the photoluminescent illumination from at least one photoluminescent marker among the plurality of photoluminescent markers of one of the first material and the second material of the sample to the one or more detectors—the first inspection subsystem among the array of inspection subsystems is configured to generate a first illumination beam in a first time interval and direct the first illumination beam to a first part of the sample including a first set of photoluminescent markers so that the first set of photoluminescent markers emits photoluminescent illumination in the first time interval, and the first inspection subsystem among the array of inspection subsystems is configured to, when the first set of photoluminescent markers is emitting photoluminescent illumination, the first time The apparatus is configured to generate a first optical image by imaging the first portion of the sample in a segment, and one or more additional inspection subsystems among the array of inspection subsystems are configured to generate an additional set of illumination beams in one or more additional time segments and to direct the additional set of illumination beams toward one or more additional portions of the sample including one or more additional sets of photoluminescent markers so that the one or more additional sets of photoluminescent markers emit photoluminescent illumination in the one or more additional time segments, and one or more additional inspection subsystems among the array of inspection subsystems are configured to generate one or more additional optical images by imaging the one or more additional portions of the sample in the one or more additional time segments when the one or more additional sets of photoluminescent markers are emitting photoluminescent illumination.A multi-element super-resolution inspection system comprising: a controller communicatably coupled to an array of the inspection subsystems and comprising one or more processors, wherein the one or more processors are configured to execute a program instruction that causes the one or more processors to receive the first optical image from the first inspection subsystem; receive the one or more additional optical images from the one or more additional inspection subsystems; generate an accumulated optical image based on the received first optical image and the one or more additional received optical images; determine the positions of the plurality of photoluminescent markers based on the accumulated optical image; and determine the pattern of the sample based on the determined positions of the plurality of photoluminescent markers. Claim 2 A multi-element super-resolution inspection system according to claim 1, wherein the one or more processors are configured to execute a program instruction that causes the one or more processors to identify one or more defects of the sample based on the determined pattern of the sample. Claim 3 A multi-element super-resolution inspection system according to claim 1, wherein the generated plurality of optical images include a point spread function of one or more active photoluminescent markers among the plurality of photoluminescent markers, and the one or more active photoluminescent markers include one or more photoluminescent markers that emit photoluminescent light. Claim 4 A multi-element super-resolution inspection system according to claim 1, wherein the set of optical elements comprises at least one diffraction optical element. Claim 5 A multi-element super-resolution inspection system according to claim 1, wherein the set of optical elements comprises at least one lens. Claim 6 A multi-element super-resolution inspection system according to claim 1, wherein the set of optical elements comprises at least one mirror. Claim 7 A multi-element super-resolution inspection system according to claim 1, wherein the one or more light sources are configured to excite the plurality of photoluminescent markers of one of the first material and the second material of the sample. Claim 8 A multi-element super-resolution inspection system according to claim 1, wherein the plurality of photoluminescent markers comprises at least one of one or more organic dyes, one or more fluorophores, one or more quantum dots, one or more carbon dots, one or more transition metals, one or more conjugated polymers, and one or more phosphorescent nanoparticles. Claim 9 A multi-element super-resolution inspection system according to claim 1, wherein one of the first material and the second material comprises at least one of porous carbon-doped organosilicon, copper, cobalt, ruthenium, tungsten, aluminum, silicon, polycrystalline silicon, titanium nitride, and silicon nitride. Claim 10 In claim 1, the sample comprises a substrate, a multi-element super-resolution inspection system. Claim 11 In claim 10, the substrate comprises a wafer, a multi-element super-resolution inspection system. Claim 12 A method for super-resolution inspection, comprising: generating a first optical image of a sample using a first inspection subsystem among an array of inspection subsystems, wherein the sample comprises at least a first material and at least a second material, wherein the first material is different from the second material, and the sample comprises a plurality of photoluminescent markers configured to selectively bind to one of the first material and the second material to enhance a feature of interest on the sample, wherein the first optical image is generated when a first set of photoluminescent markers among the plurality of photoluminescent markers emits photoluminescent illumination in a first time interval; generating one or more additional optical images using one or more additional inspection subsystems among the array of inspection subsystems, wherein the one or more additional optical images are generated when one or more additional sets of photoluminescent markers among the plurality of photoluminescent markers emit photoluminescent illumination in one or more additional time intervals; generating a cumulative optical image based on the generated first optical image and the generated one or more additional optical images; and generating the plurality of A method for super-resolution inspection comprising: a step of determining the positions of photoluminescent markers; and a step of determining the pattern of the sample based on the determined positions of the plurality of photoluminescent markers. Claim 13 A method for super-resolution inspection according to claim 12, wherein the step of generating a first optical image using a first inspection subsystem among an array of inspection subsystems—the first optical image is generated when a first set of photoluminescent markers among a plurality of photoluminescent markers emits photoluminescent illumination in a first time interval— comprises: generating a first illumination beam using a first illumination source of the first inspection subsystem in a first time interval; selectively directing the first illumination beam to the sample using a first set of optical elements in the first time interval; and detecting a first photoluminescent illumination beam preferentially emitted from a first set of photoluminescent markers selectively bound to one of the first material and the second material of the sample using a first detector in the first time interval. Claim 14 A method for super-resolution inspection according to claim 12, wherein the step of generating one or more additional optical images using one or more additional inspection subsystems among the array of inspection subsystems—the one or more additional optical images are generated when one or more additional sets of photoluminescent markers among the plurality of photoluminescent markers emit photoluminescent illumination in one or more additional time intervals— comprises: generating one or more additional sets of illumination beams using one or more additional sets of illumination sources of one or more additional inspection subsystems in one or more additional time intervals; selectively directing one or more additional sets of illumination beams to the sample using one or more additional sets of optical elements in one or more additional time intervals; and detecting one or more additional sets of photoluminescent illumination beams preferentially emitted from one or more additional sets of photoluminescent markers selectively bound to one of the first material and the second material of the sample using one or more additional sets of detectors in one or more additional time intervals. Claim 15 A method for super-resolution inspection according to claim 12, further comprising the step of identifying one or more defects of the sample based on the determined pattern of the sample. Claim 16 A method for super-resolution inspection according to claim 13, wherein the first set of optical elements comprises at least one mirror. Claim 17 A method for super-resolution inspection according to claim 12, wherein one of the first optical image generated and one or more additional optical images generated comprises a point diffusion function of one or more active photoluminescent markers among the plurality of photoluminescent markers, and the one or more active photoluminescent markers comprises one or more photoluminescent markers that emit photoluminescent illumination. Claim 18 A method for super-resolution inspection according to claim 12, wherein the plurality of photoluminescent markers comprises at least one of one or more organic dyes, one or more quantum dots, one or more carbon dots, one or more transition metals, and one or more conjugated polymers. Claim 19 A method for super-resolution inspection according to claim 12, wherein one of the first material and the second material comprises at least one of porous carbon-doped organosilicon, copper, cobalt, ruthenium, tungsten, aluminum, silicon, polycrystalline silicon, titanium nitride, and silicon nitride. Claim 20 A system comprising a controller including one or more processors, wherein the one or more processors cause the one or more processors to generate a first optical image of a sample using a first inspection subsystem among an array of inspection subsystems, wherein the sample comprises at least a first material and at least a second material, wherein the first material is different from the second material, and the sample comprises a plurality of photoluminescent markers configured to selectively bind to one of the first material and the second material to enhance a feature of interest on the sample, and the first optical image is generated when a first set of photoluminescent markers among the plurality of photoluminescent markers emits photoluminescent illumination in a first time interval -; and generate one or more additional optical images using one or more additional inspection subsystems among the array of inspection subsystems, wherein the one or more additional optical images are generated when one or more additional sets of photoluminescent markers among the plurality of photoluminescent markers emit photoluminescent illumination in one or more additional time intervals -; A system comprising: generating a cumulative optical image based on the first optical image generated above and one or more additional optical images; determining the positions of the plurality of photoluminescent markers based on the cumulative optical image; and executing a program instruction to determine the pattern of the sample based on the determined positions of the plurality of photoluminescent markers. Claim 21 In claim 20, the system is configured such that the one or more processors also execute a program instruction that causes the one or more processors to identify one or more defects of the sample based on the determined pattern of the sample. Claim 22 delete Claim 23 delete

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