Large scale overlay metrology sampling with multiple measurement columns

Abstract

A multi-column metrology tool can include two or more measurement columns distributed along a column direction, where the two or more measurement columns simultaneously probe two or more measurement areas on a sample including metrology targets. A measurement column can include an illumination subsystem for directing illumination to the sample, a collection subsystem including a collection lens for collecting measurement signals from the sample and directing them to one or more detectors, and a column positioning subsystem for adjusting the position of the collection lens. A measurement area of a measurement column can be defined by the field of view of the collection lens and the range of the positioning system in a lateral plane. The tool can further include a sample positioning subsystem for scanning the sample along a scan path different from the column direction to position metrology targets within the measurement areas of the measurement columns for measurement.

Description

[0001] Cross-reference of related applications

[0002] This application claims the benefit of U.S. Provisional Application No. 63 / 116.163, filed November 20, 2020, entitled “MASSIVE OVERLAY METROLOGY SAMPLING FOR SEMICONDUCTORS WAFER LITHOGRAPHY AND PATTERNING PROCESS CONTROL BY MULTI OPTICAL COLUMNS AND SIGNALMULTIPLEXING”, filed under 35 U.S. SC §119(e), which is inventored by Jon Madsen, Andrei Shchegrov, Yossi Simon, Andy Hill, Yoram Uziel, and Amnon Manassen. The entire application is incorporated herein by reference. Technical Field

[0003] This disclosure generally relates to optical metrology, and more specifically, to optical metrology having multiple measurement columns for high-processing-capacity sampling. Background Technology

[0004] The need to reduce feature size and increase feature density leads to a corresponding increase in the demand for accurate and efficient metrology.

[0005] One approach to increasing the efficiency and processing power of metrology systems is to utilize optical metrology tools and dedicated metrology targets suitable for measurement using these tools. For example, optical metrology can typically offer significantly higher processing power than particle-based metrology systems (e.g., but not limited to, electron beam metrology systems), although accuracy may be limited by the wavelength of light within the system. However, the use of dedicated superimposed targets and the sampling of large numbers of samples across sample distributions can utilize optical techniques to provide sufficient accuracy beyond the overall processing power of particle-based systems.

[0006] Next-generation semiconductor devices may require sub-nanometer stacking accuracy requirements associated with the relative registration of subsequent layers in semiconductor manufacturing processes. As stacking tolerances become more stringent, the number of stacking targets required to provide the necessary level of control continues to increase. Therefore, systems and methods for providing accurate and efficient metrology are expected. Summary of the Invention

[0007] According to one or more illustrative embodiments of this disclosure, a multi-column metrology tool is disclosed. In one illustrative embodiment, the tool includes two or more measuring columns distributed along a column direction, wherein the two or more measuring columns simultaneously probe two or more measurement regions on a sample containing multiple metrological targets. In another illustrative embodiment, a particular measuring column of the two or more measuring columns includes an illumination subsystem for guiding illumination from at least one of one or more illumination sources to the sample, a light-collecting subsystem including a light-collecting lens for collecting measurement signals from the sample and guiding the measurement signals to one or more detectors, and a column positioning subsystem for adjusting the position of the light-collecting lens in a transverse plane parallel to the sample plane for measurement. In another illustrative embodiment, the measurement region of the particular measuring column is defined by the field of view of the light-collecting lens and the extent of the positioning system in the transverse plane. In another illustrative embodiment, the tool includes a sample positioning subsystem for scanning the sample along a scan path different from the column direction, wherein the scan path positions the metrological targets of the multiple metrological targets within the measurement regions of the two or more measuring columns for measurement. In another illustrative embodiment, the column positioning subsystem of the two or more measuring columns positions the light-collecting lens of the two or more measuring columns to align the metrological target in the measurement area with the field of view of the light-collecting lens along the scanning path for the measurement.

[0008] According to one or more illustrative embodiments of this disclosure, a multi-column metrology tool is disclosed. In one illustrative embodiment, the tool includes two or more measuring columns distributed in a two-dimensional pattern, wherein the two or more measuring columns simultaneously probe two or more measurement regions on a sample containing a plurality of metrological targets, and wherein the measurement regions of the two or more measuring columns are distributed to cover one or more selected regions of the sample containing at least some of the plurality of metrological targets. A particular measuring column of the two or more measuring columns may include an illumination subsystem for directing illumination from at least one of one or more illumination sources to the sample, a light-collecting subsystem including a light-collecting lens for collecting measurement signals from the sample and directing the measurement signals to one or more detectors, and a column positioning subsystem for adjusting the position of the light-collecting lens in a transverse plane parallel to the sample plane for measurement, wherein the measurement region of the particular measuring column is defined by the field of view of the light-collecting lens and the extent of the positioning system in the transverse plane. In another illustrative embodiment, the column positioning subsystem of the two or more measuring columns adjusts the position of the respective light-collecting lens to align with the metrological targets of the plurality of metrological targets in the respective measurement region.

[0009] According to one or more illustrative embodiments of this disclosure, a multi-column metrology method is disclosed. In one illustrative embodiment, the method includes providing illumination to two or more measurement columns, wherein the two or more measurement columns simultaneously detect two or more measurement regions on a sample comprising multiple metrological targets. In another illustrative embodiment, a particular measurement column of the two or more measurement columns includes an illumination subsystem for directing illumination from at least one of one or more illumination sources to the sample, a light-collecting subsystem including a light-collecting lens for collecting measurement signals from the sample and directing the measurement signals to one or more detectors, and a column positioning subsystem for adjusting the position of the light-collecting lens in a transverse plane parallel to the sample plane for measurement, wherein the measurement region of the particular measurement column is defined by the field of view of the light-collecting lens and the extent of the positioning system in the transverse plane. In another illustrative embodiment, the method includes directing the illumination light to the metrological targets within the measurement field of view of the two or more measurement columns. In another illustrative embodiment, the method includes collecting multiplexed measurement signals from the two or more measurement columns. In another illustrative embodiment, the method includes detecting the multiplexed measurement signal on one or more detectors. In another illustrative embodiment, the method includes generating metrological data of the metrological target based on the detected measurement signal.

[0010] According to one or more illustrative embodiments of this disclosure, a multi-column metrology method is disclosed. In one illustrative embodiment, the method includes generating a first set of calibration measurements on a sample using one or more calibration measurement columns of a multi-column metrology tool. In another illustrative embodiment, the method includes generating a second set of calibration measurements on the one or more calibration targets using one or more test measurement columns of the multi-column metrology tool, wherein the one or more test measurement columns provide measurement accuracy different from that of the one or more calibration columns. In another illustrative embodiment, a particular calibration measurement column or a particular test measurement column includes an illumination subsystem for directing illumination from at least one of one or more illumination sources to the sample, a light-collecting subsystem including a light-collecting lens for collecting measurement signals from the sample and directing the measurement signals to one or more detectors, and a column positioning subsystem for adjusting the position of the light-collecting lens in a transverse plane parallel to the sample plane for measurement, wherein the measurement area of ​​the particular measurement column is defined by the field of view of the light-collecting lens and the extent of the positioning system in the transverse plane. In another illustrative embodiment, the method includes calibrating the one or more test measurement columns based on the first and second sets of calibration measurements. In another illustrative embodiment, the method includes using the one or more test measurement columns to generate one or more calibrated measurements that are different from the one or more calibration targets.

[0011] It should be understood that the foregoing overview and the following detailed description are merely illustrative and explanatory and do not necessarily limit the invention as claimed. The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and, together with the overview, serve to explain the principles of the invention. Attached Figure Description

[0012] Those skilled in the art will better understand the many advantages of this disclosure by referring to the accompanying drawings, among which:

[0013] Figure 1A This is a conceptual view of an optical metrology system having a superimposed metrology tool with multiple measuring columns, according to one or more embodiments of the present disclosure.

[0014] Figure 1B This is a conceptual view of an optical metrology system according to one or more embodiments of the present disclosure, illustrating the relative positioning of the measuring column and the sample.

[0015] Figure 1C This is a conceptual view of a portion of a multi-column stacked metrology tool comprising an associated illumination source and detector having an optical measurement column that provides illumination and light collection via a common mirror, according to one or more embodiments of this disclosure.

[0016] Figure 1D This is a partial conceptual view of a multi-column stacked metrology tool comprising an associated illumination source and detector having an optical measurement column that provides illumination and light collection through a separate path, according to one or more embodiments of this disclosure.

[0017] Figure 1E This is a partial conceptual view of a multi-column stacked metrology tool comprising EUV measurement columns having associated EUV illumination sources and detectors, according to one or more embodiments of this disclosure.

[0018] Figure 1F This is a partial conceptual view of a multi-column stacked metrology tool comprising an X-ray measurement column having associated particle illumination sources and detectors, according to one or more embodiments of this disclosure.

[0019] Figure 1G This is a partial conceptual view of a multi-column stacked metrology tool comprising a particle-based measurement column 10 having associated particle illumination sources and detectors, according to one or more embodiments of the present disclosure.

[0020] Figure 2A This is a conceptual view of a series of measurement columns providing independent illumination and light collection across a sample distribution according to one or more embodiments of this disclosure.

[0021] Figure 2BThis is a conceptual view of a series of measurement columns across a sample distribution sharing a common illumination source and a common detector, according to one or more embodiments of this disclosure.

[0022] Figure 3A This is a conceptual view of a lighting multiplexer according to one or more embodiments of the present disclosure.

[0023] Figure 3B This is a conceptual view of a detection multiplexer according to one or more embodiments of the present disclosure.

[0024] Figure 4A This is a conceptual view of an optical metrology system comprising a series of measuring columns 104 distributed along the column direction, according to one or more embodiments of the present disclosure.

[0025] Figure 4B This is a conceptual view of a measurement scan band on a sample containing a nonlinear distribution of measurement targets, according to one or more embodiments of this disclosure.

[0026] Figure 5 This is a conceptual view of an optical metrology system comprising a two-dimensional distribution of measuring columns according to one or more embodiments of the present disclosure.

[0027] Figure 6 This is a flowchart illustrating the steps performed in a method for optical metrology according to one or more embodiments of the present disclosure.

[0028] Figure 7 This is a flowchart illustrating the steps performed in a self-calibration method 700 for a multi-column metrology tool according to one or more embodiments of the present disclosure. Detailed Implementation

[0029] The subject matter of the disclosure will now be described in detail with reference to the accompanying drawings. This disclosure has been particularly shown and described with respect to certain embodiments and their specific features. The embodiments set forth herein are to be regarded as illustrative rather than restrictive. It will be readily apparent to those skilled in the art that various changes and modifications in form and detail can be made without departing from the spirit and scope of this disclosure.

[0030] Embodiments of this disclosure relate to multi-column stacking metrology for providing high-processing-capability sampling of stacked targets across sample distributions. In some embodiments, the stacking metrology tool includes a plurality of measurement columns, each of which includes an illumination subsystem for directing illumination from an illumination source to the sample, and a light-gathering subsystem for collecting light from the sample as a measurement signal and directing the measurement signal to a detector. Additionally, at least some of the measurement columns may include a dedicated column positioning subsystem (e.g., having one or more translation stages) for providing independent positioning of the measurement columns in any direction. Thus, each measurement column may have a measurement area based on both the measurement field of view of the light-gathering subsystem (e.g., associated with the spatial extent of the sample from which the light-gathering subsystem can collect measurement signals) and the range of motion of the column positioning subsystem. It should be appreciated herein that multiple measurement columns combined with the independent positioning of at least some of the measurement columns can provide a flexible platform for parallel measurement metrology targets across samples with high overall measurement processing power.

[0031] As should be considered herein, a measurement column may generally contain any type of illumination source known in the art suitable for providing superimposed measurements. For example, a measurement column may contain an optical measurement column for illuminating the sample with light having a selected spectrum and capturing reflected, diffracted, and / or scattered light from the sample for measurement. The optical measurement column may utilize illumination of any selected wavelength, including (but not limited to) extreme ultraviolet (EUV), deep ultraviolet (DUV), vacuum ultraviolet (VUV), ultraviolet (UV), visible, or infrared (IR) wavelengths. By another example, a measurement column may contain an X-ray measurement column for illuminating the sample with X-ray illumination and collecting X-ray measurement signals from the sample for measurement. By yet another example, a measurement column may contain a particle beam measurement column for illuminating the sample with a particle beam (e.g., but not limited to, an electron beam, an ion beam, or a neutral particle beam). The particle beam measurement column may then collect various measurement signals from the sample (e.g., but not limited to, backscattered electrons, secondary electrons, or luminescence) for measurement. Furthermore, multi-column superimposition tools may contain any combination of measurement columns and any selected illumination source.

[0032] For the purposes of this disclosure, the term overlay metrology broadly refers to the measurement of misalignment of features formed by two or more exposures on a common portion of a sample. In this respect, overlay metrology can provide measurements of alignment of features formed on two or more layers on a sample, as well as measurements of alignment of features formed by successive exposures (e.g., double patterning, triple patterning, or the like) on a common sample layer. Furthermore, overlay measurements can be performed at any suitable location on the sample. For example, overlay measurements can be performed on one or more overlay targets designed to provide overlay measurements representative of the device features of interest. Such overlay targets can be positioned on the sample, in a runner, or in any other suitable location along with the die. By another example, overlay measurements can be performed directly on device features. Additionally, overlay measurements can be performed on features associated with any step in the manufacturing process. In this respect, the systems and methods disclosed herein are generally applicable to (but not limited to) post-development inspection (ADI), post-etching inspection (AEI), or post-cleaning inspection (ACI). For the purposes of this disclosure, the term superposition target is used to broadly describe any suitable portion of a sample to be characterized by a measurement column of a superposition metrology tool, including (but not limited to) specific superposition target or device features applicable to direct superposition measurements.

[0033] The speed at which a translation stage in a measuring column can adjust the position of the measuring column can be at least partially based on the mass of the measuring column. A greater mass results in a slower positioning speed. Therefore, it is desirable to limit the number and / or mass of components positioned within the measuring column. In some embodiments, at least one measuring column receives illumination from an external illumination source. In this way, the measuring column does not need to contain a mass associated with the illumination source. Similarly, in some embodiments, at least one measuring column directs a measurement signal to a detector external to the measuring column. However, it should be understood that this disclosure extends to metrology systems having any combination of illumination sources or detectors on the measuring column. Furthermore, the measuring column can be coupled to external components (e.g., illumination sources, detectors, or the like) using any technology known in the art (including, but not limited to, fiber optics or free-space optics).

[0034] Additional embodiments of this disclosure relate to the multiplexing and / or demultiplexing of illumination from a lighting source or measurement signals directed to a detector. In this manner, measurement columns can share an illumination source and / or a detector.

[0035] In some embodiments, illumination from a lighting source is separated along multiple paths and guided to multiple measurement columns (e.g., some or all of the measurement columns). For example, the illumination guided to the sample through various measurement columns may generally have common properties (e.g., polarization, wavelength, temporal properties, particle energy, or the like) for providing common illumination conditions through the various measurement columns. By another example, the illumination guided to the sample through various measurement columns may have different properties. In this configuration, the illumination may be multiplexed based on one or more properties of the illumination.

[0036] In some embodiments, measurement signals from multiple measurement columns are directed to a common detector. In this configuration, the measurement signals directed from the various measurement columns to the common detector may have different properties (e.g., polarization, wavelength, time properties, or the like). Furthermore, the measurement signals from the various measurement columns may be multiplexed based on one or more properties of the measurement signals. The detector may then receive the measurement signals and generate a separate detector signal associated with each measurement column. In another embodiment, the metrology system further includes a detection multiplexer for receiving multiplexed light from the various measurement columns and arranging it along a common path before directing it to one or more detectors.

[0037] Additional embodiments of this disclosure relate to various configurations of independently locatable measurement columns for facilitating large-scale sampling of numerous metrological targets across a sample distribution. In some embodiments, multiple measurement columns are distributed along a line along the column direction.

[0038] For example, the metrology system may include measurement columns extending at least the length of the sample. In this way, the sample can be scanned along a scanning direction that may (but does not need to) be orthogonal to the column direction. In this configuration, the metrological targets can be distributed along a linear path along the scanning direction such that scanning the sample along the scanning direction brings the metrological targets into the measurement areas of various measurement columns. Furthermore, the column positioning subsystem can adjust the position of the measurement columns as needed to detect the metrological targets.

[0039] As another example, a metrology system may include measurement columns distributed in a two-dimensional pattern across the sample. In this respect, the measurement areas of the various measurement columns can be distributed across the sample in two dimensions, and a column positioning subsystem can position each measurement column to detect the metrological target within its associated measurement area.

[0040] This paper should further consider that metrology systems incorporating independently locatable measurement columns can detect metrological targets in either a scanning mode where the sample is in motion during measurement or in a static mode where the sample is static during measurement (e.g., moving and measuring or MAM mode). Furthermore, the metrology system can switch between scanning and static modes as needed.

[0041] Additional embodiments of this disclosure relate to the self-calibration of a multi-column stacking tool having measurement columns and different illumination sources. Stacked metrology tools with different illumination sources can have different trade-offs between measurement accuracy and measurement processing power. For example, particle beam metrology systems (e.g., electron beam metrology systems) can provide relatively high accuracy but relatively low processing power, while optical metrology systems can provide relatively high processing power but relatively low accuracy. However, it should be considered herein that metrological data from one measurement column of a multi-column stacking tool can be used to calibrate metrological data from another measurement column to provide the advantages of both types of measurement columns. U.S. Patent Publication No. 2019 / 0003988, published January 3, 2019, substantially describes training a metrology tool using data from a second metrology tool, which is incorporated herein by reference in its entirety. Embodiments of this disclosure relate to using a single stacking tool with different types of measurement columns to provide self-calibrated measurement data. This tool can benefit from rapid self-calibration relative to multi-tool systems, reduced complexity, and reduced cost.

[0042] In some embodiments, a multi-column superposition metrology tool includes one or more measurement columns of a first type and one or more measurement columns of a second type, wherein the first and second type measurement columns may have different processing capabilities and / or measurement accuracies. For example, the first type measurement columns may have relatively higher accuracy and relatively lower processing capabilities compared to the second type measurement columns. By way of non-limiting illustration, the first type measurement columns may include (but are not limited to) particle beam metrology columns or X-ray metrology columns, while the second type measurement columns may include (but are not limited to) optical metrology columns. The multi-column metrology tool may then use both the first and second types of measurement columns to generate superposition measurements of one or more superimposed targets and then use metrology data from the second type measurement columns to calibrate metrology data from the first type measurement columns. In this way, the calibrated second type measurement columns can provide increased accuracy (e.g., compared to an uncalibrated configuration) while maintaining relatively high processing capabilities. Therefore, the multi-column metrology tool can use only the calibrated second type measurement columns to provide measurements of future metrology targets to generate accurate metrology data with high processing capabilities.

[0043] For reference Figures 1A to 7 The present disclosure provides a more detailed description of a system and method for measurement using multiple measuring columns, based on one or more embodiments thereof.

[0044] Figure 1A This is a conceptual view of a superimposed metering system 100 having a multi-column superimposed metering tool 102 with multiple measuring columns 104, according to one or more embodiments of this disclosure. For example, Figure 1A This describes a multi-column stacked metrology tool 102 with N measuring columns 104. In a general sense, the stacked metrology system 100 may contain any number of measuring columns 104.

[0045] In one embodiment, the multi-column stacking metrology tool 102 includes at least one illumination source 106 for generating illumination 134 to guide it to a sample 108 through one or more measurement columns 104, and at least one detector 110 for capturing measurement signals (e.g., light and / or particles from the sample 108) from the sample 108 by the one or more measurement columns 104. Furthermore, any particular measurement column 104 may be configured in a reflective configuration (e.g., where the measurement signal comprises reflected, diffracted, or scattered light on the same side of the incident illumination 134 as the sample 108) or in a transmissive configuration (e.g., where the measurement signal comprises transmitted, diffracted, or scattered light on the opposite side of the incident illumination 134 as the sample 108).

[0046] The illumination source 106 (e.g., one or more illumination sources 106 in the superposition metrology system 100) may comprise any type of source suitable for generating illumination suitable for superposition measurements. For example, the illumination source 106 may comprise an electromagnetic source for generating electromagnetic illumination 134 having wavelengths in any region of the electromagnetic spectrum (including, but not limited to, X-rays, EUV, DUV, VUV, UV visible light, or IR spectral ranges). By another example, the illumination source 106 may comprise a particle beam source for generating particle-based illumination 134 (e.g., but not limited to, electron beams, ion beams, or neutral particle beams).

[0047] In one embodiment, the illumination source 106 is a laser source. For example, the illumination source 106 may include (but is not limited to) one or more narrowband laser sources, broadband laser sources, supercontinuum laser sources, white light laser sources, or the like. In this respect, the illumination source 106 can provide illumination with high coherence (e.g., high spatial coherence and / or temporal coherence).

[0048] In another embodiment, the illumination source 106 comprises a plasma source, such as (but not limited to) a laser sustained plasma (LSP) source. For example, the illumination source 106 may comprise (but is not limited to) an LSP lamp, LSP bulb, or LSP chamber suitable for housing one or more elements capable of emitting broadband illumination when excited into a plasma state by a laser source. In another embodiment, the illumination source 106 comprises a lamp source. For example, the illumination source 106 may comprise (but is not limited to) an arc lamp, a discharge lamp, an electrodeless lamp, or the like. In this respect, the illumination source 106 can provide illumination with low coherence (e.g., low spatial coherence and / or temporal coherence).

[0049] In another embodiment, illumination source 106 includes an X-ray source for generating X-ray illumination 134 of any wavelength (including, but not limited to, hard or soft X-rays). For example, illumination source 106 may include a hard X-ray source for forming a spatially coherent hard X-ray beam with an energy between about 3 and 20 keV. For example, illumination 134 may include X-rays with an energy between about 5 and 6 keV. By another example, illumination source 106 may include a laser-generated plasma (LPP) X-ray source. For example, illumination source 106 may include a laser source configured to generate a laser beam for pumping plasma. In response to laser radiation, the plasma can generate a spatially coherent X-ray beam. By another example, illumination source 106 may include, but is not limited to, a Compton X-ray source.

[0050] In some embodiments, the illumination source 106 or the multi-column stacked metrology tool 102 may more typically include any number of adjustment elements configured to improve the coherence of the x-ray illumination 134. For example, the measurement column 104 may include (but is not limited to) one or more x-ray optics for capturing, refocusing, spatially filtering, and / or modulating x-rays output from the plasma to achieve a desired level of spatial coherence.

[0051] In another embodiment, the illumination source 106 includes a particle source. For example, the illumination source 106 may include (but is not limited to) an electron gun or an ion gun. In another embodiment, the illumination source 106 is configured to provide a particle beam with tunable energy. For example, the illumination source 106 including an electron source may (but is not limited to) provide an accelerating voltage in the range of 0.1 to 30 kV. As another example, the illumination source 106 including an ion source may (but does not need to) provide an ion beam in the range of 1 to 50 keV.

[0052] The illumination source 106 may further provide (but does not need to provide) illumination in the form of one or more illumination beams or illumination lobes. In this regard, the multi-pillar superposition metrology tool 102 may provide dipole illumination, orthogonal illumination, or the like. Multiple illumination beams may be generated in various ways. In one embodiment, the multi-pillar superposition metrology tool 102 includes one or more apertures at the illumination pupil plane to divide the illumination from the illumination source 106 into one or more illumination beams. In another embodiment, the superposition metrology system 100 generates illumination directly in one or more illumination beams. For example, one or more illumination sources 106 may generate illumination directly in one or more illumination beams. For example, one or more illumination sources 106 may provide light in two or more optical fibers, wherein the light output from each optical fiber provides an illumination beam. These optical fibers may be arranged in an illumination pupil or may be paired with individual illumination optics to directly illuminate the sample 108. In another example, the illumination source 106 generates multi-lobed illumination by diffracting the light source into two or more diffraction orders, wherein the illumination lobes are formed by at least some of the diffraction orders of the light source. The efficient generation of multiple illumination lobes by controlled diffraction is generally described in U.S. Patent Publication No. 2020 / 0124408, published on April 23, 2020, which is incorporated herein by reference in its entirety. By another example, the superposition metering system 100 may include one or more beam manipulation or diffraction optics to selectively adjust the position of at least one illumination beam within the illumination pupil to provide selective control of the illumination incident angle.

[0053] Additionally, the spatial profile of illumination containing one or more illumination beams on sample 108 can be controlled by an illumination field aperture to have any selected spatial profile.

[0054] The multi-column stacking metrology tool 102 may include any number or type of detectors 110 suitable for capturing the measurement signal 122 indicating the stacking from the sample 108. For example, detector 110 may include one or more sensors (e.g., photodetectors, photomultiplier tubes (PMTs), X-ray detectors, or the like) suitable for capturing light having any wavelength in the electromagnetic spectrum. By another example, detector 110 may include one or more particle detectors suitable for capturing particles (e.g., electrons, particles, neutral particles) from the sample 108. By another example, detector 110 may include a scintillation element coupled to an optical detector for detecting particles and / or photons from the sample surface.

[0055] In one embodiment, detector 110 is adapted to characterize static samples. In this regard, multi-column stacking metrology tool 102 can operate in a static mode in which sample 108 is static during measurement. For example, detector 110 may comprise an imaging detector having a 2D pixel array suitable for generating 2D images, such as (but not limited to) charge-coupled device (CCD) or complementary metal-oxide-semiconductor (CMOS) devices, suitable for generating 2D images (e.g., field plane images, pupil plane images, or the like).

[0056] In another embodiment, detector 110 includes one or more detectors 110 suitable for characterizing moving samples (e.g., scanned samples). In this regard, the multi-column stacking metrology tool 102 or any of its measurement columns 104 may operate in a scanning mode relative to the measurement field during measurement of sample 108. For example, detector 110 may include a 2D pixel array having a capture time and / or refresh rate sufficient to capture one or more images during scanning at selected image tolerances (e.g., image blur, contrast, sharpness, or the like). By another example, detector 110 may include a line scan detector for continuously generating images one row of pixels at a time. By another example, detector 110 may include a time-delay integration (TDI) detector that generates continuous images of sample 108 when the movement of sample 108 is synchronized with a charge transfer clock signal in the TDI detector.

[0057] In another embodiment, the measurement column 104 (e.g., one or more of N measurement columns 104) includes a column positioning subsystem 112 for providing independent positioning of the measurement column 104. The column positioning subsystem 112 may include one or more actuators configured to independently position the measurement column 104 along one or more directions. For example, the column positioning subsystem 112 may include (but is not limited to) one or more linear translation stages, one or more rotary translation stages, or one or more tilt / flip actuators. In this way, the column positioning subsystem 112 of the measurement column 104 can position components of the measurement column 104 relative to the sample 108 along any desired dimension. For example, the column positioning subsystem 112 can facilitate alignment of the measurement column 104 with a metrological target on the sample 108.

[0058] In another embodiment, the superimposed measurement system 100 includes a sample positioning system 114 for fixing and / or positioning the sample 108 relative to any measurement post 104. The sample positioning system 114 may include one or more actuators configured to independently position the sample 108 along one or more directions. For example, the sample positioning system 114 may include (but is not limited to) one or more linear translation stages, one or more rotary translation stages, or one or more tilt / flip actuators. In this way, the sample positioning system 114 can position the sample 108 relative to the measurement post 104 at any selected orientation.

[0059] Figure 1B This is a conceptual view of a superimposed measurement system 100 according to one or more embodiments of the present disclosure, illustrating the relative positioning of the measurement column 104 and the sample 108. Figure 1B For clarity, only a single measuring column 104 is described in this text. The superimposed measurement system 100 may be mounted on or otherwise include at least one structural support 116 (e.g., a table, wall, ceiling, or the like) to secure various components, such as (but not limited to) the sample positioning system 114 and column positioning subsystem 112 for each measuring column 104. Figure 1B In this embodiment, the sample positioning system 114 orients the sample 108 in the transverse plane (here, the XY plane) and the measuring column 104 illuminates the sample 108 along the axial direction (here, the Z direction). For example, the measuring column 104 may illuminate the sample 108 using normal incident light propagating along the Z-axis or using oblique light having at least an directional component along the Z-axis. In another embodiment, each measuring column 104 is mounted to a column positioning subsystem 112, which itself is mounted to a structural support 116. In another embodiment, the sample positioning system 114 includes a 3D translation stage for providing lateral translation of the sample 108 along the transverse plane (XY plane) and translation along the axial direction (Z direction). In another embodiment, the sample positioning system 114 includes a rotation stage for rotating the sample 108 in the transverse plane.

[0060] Various configurations of the measuring post 104, the illumination source 106, and the detector 110 are feasible within the spirit and scope of this disclosure, as considered herein. For example, the illumination source 106 and / or the detector 110 may be located on or outside the associated measuring post 104. For example, positioning the illumination source 106 and / or the detector 110 outside the associated measuring post 104 reduces the mass of the measuring post 104, which reduces the load on the post positioning subsystem 112. Therefore, placing these components outside the associated measuring post 104 facilitates faster and / or more accurate positioning of the measuring post 104 by the post positioning subsystem 112 compared to a case where the illumination source 106 and / or the detector 110 are part of the measuring post 104.

[0061] Each measurement column 104, when coupled with the illumination source 106 and detector 110, can be used for measurement overlay regardless of the specific positioning of the illumination source 106 and / or detector 110 relative to the associated measurement column 104. In this respect, each measurement column 104, its associated illumination source 106, and detector 110 can operate as an overlay tool, and the multi-column overlay metrology tool 102 can be characterized as multiple overlay tools providing multiple parallel overlay measurements applicable to different portions of the sample 108.

[0062] The multi-column stacking metrology tool 102 or any of its measurement columns 104 can operate as any type of stacking metrology tool known in the art. For example, the multi-column stacking metrology tool 102 or any of its measurement columns 104 can operate in imaging mode, non-imaging mode, or selectively switch between imaging and non-imaging modes. As an illustrative example, in the case of optical measurement columns 104, a detector 110 placed at a field plane conjugate to sample 108 can generate an image of sample 108. Based on the configuration of the corresponding illumination subsystem 118 and light-gathering subsystem 120, this image can include a bright-field image, a dark-field image, a phase-contrast image, or the like. By another example, one or more detectors 110 placed at the pupil plane can characterize the angular distribution of radiation from sample 108 (e.g., associated with scattering and / or diffraction of radiation by sample 108). In this way, the multi-column stacking metrology tool 102 or any of its measurement columns 104 can operate as a scattering measurement (SCOL) stacking tool. Furthermore, scattering measurement superposition can be performed by generating an image of the pupil plane or by capturing light at a selected location on the pupil plane using a non-imaging detector (e.g., a photodiode). For example, scattering measurement superposition using a non-imaging detector in the pupil plane is substantially described in U.S. Patent Application No. 17 / 142,783, filed January 6, 2021, which is incorporated herein by reference in its entirety.

[0063] The multi-column superposition metrology tool 102 or any of its measurement columns 104 can generate superimposed signals for any number of formulations configurable to define measurement parameters for superimposed measurements. For example, the formulation of an optical measurement column 104 may include (but is not limited to) illumination wavelength, detected wavelength of light emitted from the sample, size or shape of the illumination spot on the sample, angle of incident illumination, polarization of the incident illumination, polarization of the collected light, position of the incident illumination beam on the superposition target, position of the superposition target within the focal volume of the superposition metrology tool, or the like. By another example, the formulation of a particle beam measurement column 104 may include (but is not limited to) particle beam energy or beam scanning velocity. Furthermore, the multi-column superposition metrology tool 102 or any of its measurement columns 104 can be configured to generate superimposed measurements in scanning mode, static mode, or selectively switch between scanning mode and static mode.

[0064] For reference Figure 1C to 1G The distribution of components throughout the overlay metering system 100 is described in more detail according to one or more embodiments of this disclosure. Specifically, Figure 1C and 1D Explaining aspects of the optical measurement column 104, Figure 1E Explaining aspects of EUV measurement column 104, Figure 1F Explaining aspects of the X-ray measurement column 104 and Figure 1GThis section explains aspects of the particle beam measurement column 104.

[0065] In one embodiment, the measurement column 104 (e.g., one or more of N measurement columns 104) includes an illumination subsystem 118 configured to direct illumination from the illumination source 106 to the sample 108 (e.g., a measurement target on the sample 108) and a light-collecting subsystem 120 for collecting measurement signals 122 (e.g., light, particles, or the like) from the sample 108 and directing the measurement signals 122 to the detector 110. Figure 1C and 1D This document describes non-limiting examples of various configurations of the illumination subsystem 118 and the light-collecting subsystem 120. As considered herein, the various measuring columns 104 in sample 108 may have the same or different configurations.

[0066] like Figure 1C to 1G The description indicates that the illumination subsystem 118 may include one or more components suitable for modifying and / or adjusting the illumination 134 and directing the illumination 134 to the sample 108. In one embodiment, the illumination subsystem 118 includes one or more illumination path focusing elements 124 (e.g., for collimating the illumination 134, for relay pupils and / or field planes or the like). In another embodiment, the illumination subsystem 118 includes one or more illumination path control elements 126 for shaping or otherwise controlling the illumination 134. For example, the illumination path control element 126 may include (but is not limited to) one or more field stops, one or more pupil stops, one or more polarizers, one or more filters, one or more beam splitters, one or more diffusers, one or more homogenizers, one or more apodizers, one or more beam shapers, and one or more mirrors (e.g., static mirrors, translation mirrors, scanning mirrors, or the like).

[0067] Similarly, the light-gathering subsystem 120 may include one or more elements suitable for modifying and / or adjusting the measurement signal 122 from the sample 108. In one embodiment, the light-gathering subsystem 120 includes one or more light-gathering path focusing elements 128 (e.g., for collimating the measurement signal 122, for relaying the pupil and / or the field plane, or the like). In another embodiment, the light-gathering subsystem 120 includes one or more light-gathering path control elements 130 for shaping or otherwise controlling the measurement signal 122. For example, the light-gathering path control element 130 may include (but is not limited to) one or more field stops, one or more pupil stops, one or more polarizers, one or more filters, one or more beam splitters, one or more diffusers, one or more homogenizers, one or more apodizers, one or more beam shapers, and one or more mirrors (e.g., static mirrors, translation mirrors, scanning mirrors, or the like).

[0068] Figure 1CThis is a conceptual view of a portion of a multi-column stacked metrology tool 102 comprising an associated illumination source 106 and a detector 110 having an optical measurement column 104 providing illumination and light collection via a common mirror, according to one or more embodiments of this disclosure. For clarity, the additional measurement column 104 and the associated illumination source 106 and / or detector 110 are not shown. In one embodiment, the measurement column 104 includes a light-collecting lens 132 (e.g., an objective lens) for simultaneously directing illumination 134 from the illumination source 106 to the sample 108 and collecting measurement signals 122 from 108 for detection using the detector 110. In this respect, the measurement column 104 can provide through-lens (TTL) illumination of the sample 108.

[0069] Figure 1D This is a conceptual view of a portion of a multi-column stacked metrology tool 102 comprising an associated illumination source 106 and a detector 110 having an optical measurement column 104 providing illumination and light collection via separate paths, according to one or more embodiments of this disclosure. (As...) Figure 1C For clarity, the additional measurement post 104 and associated illumination source 106 and / or detector 110 are not described. In one embodiment, measurement post 104 includes separate components and / or optical paths for illumination subsystem 118 and light-gathering subsystem 120. In this respect, measurement post 104 can provide out-of-lens (OTL) illumination of sample 108. For example, as Figure 1D The description states that the measurement column 104 may include columns having a normal orientation to the sample 108 (e.g., as shown in the diagram). Figure 1C The light-collecting subsystem 120 of the light-collecting lens 132 (described in the text) and the illumination subsystem 118 having two separate illumination path focusing elements 124 configured to guide illumination 134 from illumination source 106 toward sample 108 at an angle outside the numerical aperture (NA) of the light-collecting lens 132. However, although Figure 1D This describes the oblique illumination and normal focusing, but it should be understood that the measuring column 104 can provide illumination and focusing at any desired angle.

[0070] Figure 1E This is a conceptual view of a portion of a multi-column stacked metrology tool 102 comprising an EUV measurement column 104 having an associated EUV illumination source 106 and a detector 110, according to one or more embodiments of this disclosure. It should be appreciated herein that, due to the high absorption of EUV light in many materials, the EUV measurement column 104 may require different components or layouts than optical systems suitable for visible or IR wavelengths.

[0071] In one embodiment, the multi-column stacked metrology tool 102 includes an EUV illumination path focusing element 124 for collimating or focusing EUV illumination 134 and a light-collecting path focusing element 128 (e.g., projection optics) for collecting, collimating, and / or focusing EUV measurement signals 122 from sample 108. Furthermore, the light-collecting path focusing element 128 can direct the EUV measurement signals 122 to one or more detectors 110. Illumination path focusing element 124 and / or light-collecting path focusing element 128 may include any type of focusing element suitable for use with the wavelength of light from illumination source 106. For example, illumination path focusing element 124 and / or light-collecting path focusing element 128 may include (but are not limited to) mirrors or other reflective surfaces (e.g., spherical mirrors, parabolic mirrors, elliptical mirrors, or the like). In this way, absorption losses can be mitigated or otherwise controlled. Furthermore, illumination path focusing element 124 can operate at any suitable angle of incidence. For example, a grazing angle mirror can provide efficient reflection.

[0072] Figure 1F This is a conceptual view of a portion of a multi-column stacked metrology tool 102 comprising an X-ray measurement column 104 having an associated particle illumination source 106 and a detector 110, according to one or more embodiments of this disclosure. Metrology using an X-ray source is generally described in the following patent applications: U.S. Patent No. 9,846,132, published December 19, 2017; U.S. Patent No. 10,775,323, published September 15, 2020; and U.S. Patent Publication No. 2019 / 0003988, published January 3, 2019, all of which are incorporated herein by reference in their entirety. For example, Figure 1F Description of transmission X-ray measurement column 104.

[0073] In one embodiment, the multi-column stacked metrology tool 102 includes an x-ray illumination path focusing element 124 for collimating or focusing x-ray illumination 134 and a light-collecting path focusing element 128 (e.g., but not limited to, an x-ray collimator) for collecting, collimating, and / or focusing x-ray measurement signals 122 from sample 108. For example, the multi-column stacked metrology tool 102 may include (but is not limited to) an x-ray collimator, a mirrored x-ray optics (e.g., a grazing-incident ellipsoidal mirror), a multi-capillary optics (e.g., a hollow capillary x-ray waveguide), a multilayer optics or system, or any combination thereof. In another embodiment, the multi-column stacked metrology tool 102 includes an x-ray illumination path control element 126, such as (but not limited to) an x-ray monochromator (e.g., a crystal monochromator, such as a Loxley-Tanner-Bowen monochromator or the like), an x-ray aperture, an x-ray beam stop, or a diffraction optics (e.g., a zone plate).

[0074] Figure 1G This is a conceptual view of a portion of a multi-column stacked metrology tool 102 comprising a particle-based measurement column 104 having an associated particle illumination source 106 and a detector 110, according to one or more embodiments of the present disclosure.

[0075] In one embodiment, the multi-column stacking metrology tool 102 includes one or more particle focusing elements. For example, Figure 1G The description includes illumination path focusing element 124, light-collecting path focusing element 128, or the like. For example, one or more particle focusing elements may comprise (but are not limited to) a single particle focusing element or one or more particle focusing elements forming a composite system. In another embodiment, one or more particle focusing elements include a light-collecting lens 132 configured to guide particle illumination 134 to sample 108. Furthermore, one or more particle focusing elements may comprise any type of electronic lens known in the art, including (but not limited to) electrostatic, magnetic, single-potential, or dual-potential lenses. It should be noted herein that, as Figure 1C The description of the voltage contrast imaging inspection system depicted herein and the associated description above are provided for illustrative purposes only and should not be construed as limiting. For example, the multi-column stacking metrology tool 102 may include any excitation source known in the art suitable for generating inspection data regarding sample 108. In another embodiment, the multi-column stacking metrology tool 102 includes two or more particle beam sources (e.g., electron beam sources or ion beam sources) for generating two or more particle beams. In another embodiment, the multi-column stacking metrology tool 102 includes one or more components (e.g., one or more electrodes) configured to apply one or more voltages to one or more locations on sample 108. In this respect, the multi-column stacking metrology tool 102 can generate voltage contrast imaging data.

[0076] In another embodiment, the multi-column stacked metrology tool 102 includes one or more particle detectors 110 for imaging or otherwise detecting particles emitted from the sample 108. In one embodiment, the detector 110 includes an electron collector (e.g., a secondary electron collector, a backscattered electron detector, or the like). In another embodiment, the detector 110 includes a photon detector (e.g., a photodetector, an X-ray detector, a scintillation element coupled to a photomultiplier tube (PMT) detector, or the like) for detecting electrons and / or photons from the sample surface.

[0077] Furthermore, as considered herein, components associated with illuminating sample 108 and / or collecting measurement signals 122 from the sample may be distributed within any measurement column 104, outside any measurement column 104, or shared between any measurement columns 104. For example, Figure 1CThe illustration describes a configuration in which the illumination source 106 and detector 110 are positioned outside the measuring column 104. In this configuration, where the illumination source 106 is positioned outside the measuring column 104, the overlay metrology system 100 may include an illumination connection path 136 for providing a path between the illumination source 106 and the measuring column 104. Similarly, in a configuration where the detector 110 is positioned outside the measuring column 104, the overlay metrology system 100 may include a detection connection path 138 for providing a path between the measuring column 104 and the detector 110. The illumination connection path 136 and / or the detection connection path 138 may include any combination of suitable components for providing a path for the illumination 134 and / or the measurement signal 122. As an example, in the case of optical illumination 134, the illumination connection path 136 and / or the detection connection path 138 may include one or more optical fibers. By another example, the illumination connection path 136 and / or the detection connection path 138 may include one or more free-space components. For example, the lighting connection path 136 and / or the detection connection path 138 may include one or more tiltable transmitter free space components and one or more tiltable receiver free space components for providing a stable path when the measuring column 104 is in motion.

[0078] Therefore, it should be understood that Figure 1C to 1G Provided for illustrative purposes only and not to be construed as limiting. Rather, the various components of the multi-column stacked measurement tool 102 may be distributed within one or more measuring columns 104, outside any measuring column 104, or shared between any measuring columns 104. Furthermore, the measuring column 104 associated with any illumination source 106 may have any suitable arrangement of elements. For example, the measuring column 104 associated with any illumination source 106 may be configured in either reflective or transmissive modes. By another example, the measuring column 104 associated with any illumination source 106 may have any combination suitable for illumination path focusing element 124, illumination path control element 126, light-collecting path focusing element 128, or light-collecting path control element 130, whether or not in… Figure 1C to 1G The explanation is as follows.

[0079] In another embodiment, although in Figure 1C to 1G Not specified, but the measuring column 104, the entire multi-column stacked metering tool 102, or any part thereof may be enclosed within a chamber. In this way, the atmosphere and / or pressure within the chamber can be controlled. For example, the stacked metering system 100 may include a vacuum pump for generating a vacuum of the desired intensity within the chamber. By another example, the stacked metering system 100 may include a gas flow system for filling the chamber with a selected gas composition at a selected pressure.

[0080] In some embodiments, the photon collection system 120 of the measurement column 104 can be configured to generate metrological data at different depths in the sample 108. For example, in Figure 1C to 1GIn the configuration described herein, the position of the measurement plane (e.g., image plane) of the light-collecting lens 132 relative to the surface of the sample 108 can be adjusted in many ways. In one example, the sample 108 can be translated along the axial direction (Z direction) by the sample positioning system 114. In another embodiment, the measurement post 104 can be adjusted along the axial direction (Z direction) by the post positioning subsystem 112. In another example, one or more light-collecting path focusing elements 128 can be adjusted to modify the measurement plane.

[0081] Furthermore, measurements can be provided sequentially or simultaneously at multiple measurement planes. For example, sequential measurements can be provided by sequentially moving the sample 108 or the measurement column 104 (or a portion thereof). By another example, simultaneous measurements can be provided using multiple detectors 110 and associated light-collecting path focusing elements 128 configured to produce different measurement planes for each detector 110.

[0082] For reference Figures 2A to 3B Various embodiments of illumination and light collection are described in more detail according to one or more embodiments of this disclosure.

[0083] In one embodiment, at least one measurement column 104 includes a dedicated illumination source 106 and / or detector 110. This configuration facilitates independent control and partial use of the measurement column 104. Furthermore, parameters associated with illumination and / or light collection (e.g., wavelength, polarization, spectrum, temporal nature of illumination 134, integration time of detector 122, or the like) can be independently controlled for the measurement column 104 without affecting other measurement columns 104. Figure 2A This is a conceptual view of a series of measurement columns 104 providing independent illumination and light collection across a sample 108 distribution according to one or more embodiments of this disclosure. Figure 2A In this process, each measurement column 104 receives illumination 134 from a separate illumination source 106 and directs the measurement signal 122 from the sample 108 to a separate detector 110.

[0084] In another embodiment, two or more measurement columns 104 receive illumination from a common illumination source 106. This configuration reduces system complexity and / or cost when the illumination source 106 provides sufficient output to drive the multiple measurement columns 104. Furthermore, as will be discussed in more detail below, the illumination from the common illumination source 106 may (but does not need to) be multiplexed so that different measurement columns 104 receive illumination with distinguishable parameters.

[0085] Similarly, the measurement column 104 may use a dedicated or shared detector 110. In one embodiment, each detector 110 receives a measurement signal 122 from a single measurement column 104. In another embodiment, a shared detector 110 receives measurement signals 122 from two or more measurement columns 104. Figure 2B This is a conceptual view of a series of measurement columns 104 distributed across a sample 108 according to one or more embodiments of the present disclosure, sharing a common illumination source 106 and a common detector 110.

[0086] This document should consider that the detection of measurement signals 122 from multiple measurement columns 104 may require multiplexing / demultiplexing of the measurement signals 122 based on one or more distinguishable optical characteristics (e.g., but not limited to, wavelength, polarization, or temporal characteristics, such as the relative time delay between measurement signals 122 from measurement columns 104)). Therefore, the measurement signals 122 from various measurement columns 104 can be distinguished by the detector 110, and the detector 110 can generate a separate detection signal associated with each measurement column 104. In one embodiment, the superimposed metrology system 100 includes one or more components for directing the measurement signals 122 from different measurement columns 104 to different portions of the detector 110. For example, the measurement signals 122 from various measurement columns 104 may be directed to different portions of the detector 110 along separate paths. In another example, where the measurement signal 122 is multiplexed based on wavelength, the detector 110 may include a diffraction element (e.g., a prism, diffraction grating, or the like) for physically separating the measurement signals 122 from different measurement columns 104 on the detector 110. In another embodiment, where the measurement signal 122 is multiplexed based on time characteristics (e.g., based on delay lines or the like), the measurement signals 122 from various measurement columns 104 may be directed to a common portion of the detector 110 and differentiated based on time.

[0087] In one embodiment, the generation of the multiplexed measurement signal 122 is implemented at least in part by multiplexing the illumination provided to the various measurement columns 104. In this way, the measurement signal 122 from the various measurement columns 104 can be multiplexed in a similar manner. Furthermore, multiple techniques can be used to multiplex the illumination provided to the various measurement columns 104. For example, in a configuration where each measurement column 104 has a dedicated illumination source 106, this dedicated illumination source 106 can be configured to provide illumination parameters different from those in the other measurement columns 104. By another example, components of the illumination subsystem 118 of the measurement column 104 (e.g., illumination path control element 126, illumination path focusing element 124, or the like) can be configured to provide selected illumination parameters different from those in the other measurement columns 104.

[0088] In another example, in a configuration where two or more measuring posts 104 receive illumination from a common lighting source 106, the superimposed metering system 100 may include an illumination multiplexer 140 for introducing differentiated lighting parameters into the illumination directed to the various measuring posts 104. Figure 3A This is a conceptual view of an illumination multiplexer 140 according to one or more embodiments of the present disclosure. In one embodiment, the illumination multiplexer 140 includes one or more beam splitters 302 for separating illumination 134 from illumination source 106 into one or more selected number of paths 304, wherein light from each path 304 (e.g., along illumination connection path 136) is directed to different measurement posts 104. Furthermore, the illumination multiplexer 140 may include illumination path control elements 126 and / or illumination path focusing elements 124 in any path 304 to distinguish illumination 134 directed to the various measurement posts 104. The illumination path control elements 126 and / or illumination path focusing elements 124 may be substantially the same as described in the illumination subsystem 118 relative to the measurement post 104 and may include (but are not limited to) filters, apertures, polarizers, time delay lines, or the like. In this respect, illumination multiplexing may occur outside the measurement post 104, within the measurement post 104, or by any combination of both.

[0089] In another embodiment, the generation of the multiplexed measurement signal 122 is implemented at least in part by directly multiplexing the measurement signals 122 from one or more measurement posts 104. For example, the photoconductor system 120 of the measurement post 104 can distinguish the measurement signals 122 from the other measurement posts 104 relative to the measurement signals from the other measurement posts 104. The multiplexed measurement signal 122 is particularly suitable (but not limited to) multiplexing based on polarization or time characteristics.

[0090] Figure 3B This is a conceptual view of a detection multiplexer 142 according to one or more embodiments of the present disclosure. In one embodiment, the detection multiplexer 142 includes one or more beam combiners 306 for collecting measurement signals 122 from multiple paths 308 (e.g., from multiple detection connection paths 138) into a common path 310 guided to a detector 110. In this way, the detector 110 can receive measurement signals 122 from various paths 308. Furthermore, the detection multiplexer 142 may include a beam-collecting path control element 130 and / or a beam-collecting path focusing element 128 along any path 308 to provide that the measurement signals 122 from each measurement post 104 can be distinguished by the detector 110.

[0091] However, it should be understood that Figure 3A and 3B The explanations and related descriptions herein are provided for illustrative purposes only and should not be construed as restrictive. For example, Figure 3A and 3B The illumination path focusing element 124 and the light-collecting path focusing element 128 are depicted as transmission lenses for optical wavelengths. However, it should be understood that... Figure 3A and 3B The concepts described herein can be applied to any type or combination of measurement columns 104, including (but not limited to) X-ray measurement columns 104, EUV measurement columns 104, or particle beam measurement columns 104. Therefore, the illumination multiplexer 140 and / or the detection multiplexer 142 can include any suitable components based on the illumination 134 and the measurement signal of interest 122.

[0092] For reference Figures 4A to 4B The various physical configurations of the measurement columns 104 in the overlay metrology system 100 are described in more detail according to one or more embodiments of the present disclosure. It should be considered herein that multiple measurement columns 104 may be distributed in various patterns relative to the sample 108. Furthermore, different distribution patterns of the measurement columns 104 may be suitable for scanning mode measurements, static mode measurements, or selective switching between the two.

[0093] In one embodiment, two or more measuring posts 104 are distributed along the post direction. For example, the two or more measuring posts 104 may be distributed linearly along the post direction or along a curved path having at least a directional component along the post direction.

[0094] Figure 4A This is a conceptual view of a superimposed metrology system 100 comprising a series of measuring columns 104 distributed along the column direction, according to one or more embodiments of this disclosure. Figure 4A In the middle, the direction of the column corresponds to the Y direction.

[0095] exist Figure 4A In the distribution described herein, each measuring post 104 may have a field of view comprised of the associated light-collecting subsystem 120 (e.g., the field of view of the light-collecting lens 132 in the light-collecting subsystem 120) and a range of motion comprised of the associated post positioning subsystem 112 (e.g., within...). Figure 4A The measurement field 402 is defined in the transverse XY plane as described in the text. For example, in... Figure 4A The measurement field 402 of each measurement column 104 is described as circular, and the circle may have a size defined by the radius of the field of view of the generally circular light-collecting subsystem 120 (not shown) and the range of motion of the column positioning subsystem 112 along the X and Y directions. However, the measurement field 402 may generally have any size or shape.

[0096] The measuring column 104 can perform measurements on the measurement target by using the column positioning subsystem 112 to align the field of view of the light-gathering subsystem 120 with the measurement target within its measuring field. Furthermore, for example... Figure 4AThe superimposed metrology system 100, which includes a distribution of measurement columns 104 along the column direction, as described herein, measures multiple metrological targets distributed across the sample 108 by scanning the sample 108 along one or more scan paths different from the column direction, thereby moving various metrological targets on the sample 108 through the measurement field 402 of the measurement columns 104. For example, the scan path may include (but is not limited to) scanning along the X direction.

[0097] Furthermore, a series of scan bands 404 can be defined, which can include regions on the sample 108 that are brought into the measurement field 402 of various measurement columns 104 as the sample 108 passes along the scan path through the superimposed metrology system 100. For example, Figure 4A This describes a series of parallel measurement scan bands 404 along the X direction associated with the sample 108 scanned along the X direction.

[0098] Figure 4B This is a conceptual view of a measurement scan band 404 on a sample 108 comprising a nonlinear distribution of measurement targets (or units thereof) according to one or more embodiments of this disclosure. For example, Figure 4B This describes the starting position of the field of view 406 of the photon system 120, which is approximately centered within the measurement scan band 404 along the column direction 408 perpendicular to the scanning direction 410. Figure 4B Further explanation is provided regarding the first metrological target 412 at a first position along the column direction 408 and the second metrological target 414 at a second position along the column direction 408. In one embodiment, while scanning sample 108 along scan direction 410, column positioning subsystem 112 (not shown) sequentially adjusts the field of view 406 of light-gathering subsystem 120 to align with the first metrological target 412 to provide measurement of the first metrological target 412, and then adjusts the field of view 406 of light-gathering subsystem 120 to align with the second metrological target 414 to provide measurement of the second metrological target 414. Furthermore, measurements of the first metrological target 412 and the second metrological target 414 can be performed while sample 108 is in motion along scan direction 410 (e.g., in scan mode) or while sample 108 is stationary (e.g., in static mode). In this regard, it should be understood that the description of scanning sample 108 is not limited to scan mode measurement, but more generally refers to moving sample 108 to position the selected metrological target within the measurement area of ​​measurement column 104.

[0099] Refer again Figure 4A In this paper, it should be considered that the measuring column 104 can be along any length or spatial extent along the column direction and distributed at any density. In this respect, Figure 4A The explanations provided herein are for illustrative purposes only and should not be construed as restrictive. For example, Figure 4AThe size spanning sample 108 (e.g., the expected size of sample 108 to be measured) allows the distribution of measurement columns 104 across the entire sample 108 to be characterized when scanning sample 108. However, in some embodiments, measurement columns 104 may span a length greater than or less than sample 108 along the column direction (where multiple scans may be required to measure the entire sample 108).

[0100] Through another example, Figure 4A The diagram describes the arrangement of measurement columns 104 such that measurement field 402 provides complete coverage of sample 108 along the column direction. In this respect, the entire sample 108 can be measured in a single scan. However, in some embodiments, the measurement columns 104 may be spread out along the column direction, resulting in gaps between them in measurement field 402 along the column direction. In this respect, multiple scans may be required to measure the entire sample 108. In one embodiment, the measurement columns 104 are arranged to correspond to the grooves on sample 108 that may contain metrological targets. In this case, even if gaps exist between them in measurement field 402 along the column direction, metrological targets in the grooves along the scan direction can still be measured in a single scan.

[0101] In another embodiment, a plurality of measurement posts 104 are distributed in a two-dimensional pattern. In this respect, a measurement field 402 associated with the measurement posts 104 can be distributed across sample 108. Furthermore, the post positioning subsystem 112 of each measurement post 104 can adjust the position of the measurement post 104 to align the field of view of the light-collecting subsystem 120 (e.g., the light-collecting lens 132 in the light-collecting subsystem 120) with any metrological target within the associated measurement field 402 for measurement.

[0102] Figure 5 This is a conceptual view of a superimposed metrology system 100 comprising a two-dimensional distribution of measuring columns 104, according to one or more embodiments of this disclosure. For example, Figure 5 The configuration of a superimposed metrology system 100 with four measuring posts 104 is described, wherein each measuring post 104 has a measuring field 402 spanning one-quarter of a sample 108. For example, in the case of a sample 108 having a diameter of 300 mm (e.g., corresponding to a standard size of a semiconductor wafer), the post positioning subsystem 112 of each measuring post 104 can provide a travel of approximately 150 mm in both the X and Y directions. Furthermore, Figure 5 This describes the column positioning subsystem 112 associated with each measuring column 104.

[0103] It should be considered in this document that the measurement column 104 may be distributed to provide any chosen distribution or density of the measurement field 402. In one embodiment, the measurement field 402 of the measurement column 104 may correspond to a angular section of the sample 108 (e.g., relative to the center point). In another embodiment, the measurement field 402 of the measurement column 104 may be distributed as a two-dimensional array or grid pattern.

[0104] also, Figure 5 This describes a configuration in which the measurement field 402 covers the entire sample 108, allowing measurement of the entire sample 108 without translation of the sample 108. In some embodiments, the overlay metrology system 100 is configured to provide gaps between at least some of the measurement fields 402, enabling a complete measurement of the sample 108 to be provided by translation of the sample 108. In this regard, the required range of each column positioning subsystem 112 can be reduced to facilitate faster and / or more accurate measurement of the metrological target within the associated measurement field 402.

[0105] Refer again Figure 1A In one embodiment, the overlay metering system 100 includes a controller 144 communicatively coupled to the multi-column overlay metering tool 102 and / or any of its components. In another embodiment, the controller 144 includes one or more processors 146. For example, one or more processors 146 may be configured to execute a set of program instructions maintained in a memory device 148 or memory. The one or more processors 146 of the controller 144 may include any processing element known in the art. In this sense, one or more processors 146 may include any microprocessor-type device configured to execute algorithms and / or instructions.

[0106] One or more processors 146 of controller 144 may comprise any processor or processing element known in the art. For the purposes of this disclosure, the terms “processor” or “processing element” may be broadly defined to cover any means having one or more processing or logic elements (e.g., one or more microprocessor devices, one or more application-specific integrated circuit (ASIC) devices, one or more field-programmable gate arrays (FPGAs), or one or more digital signal processors (DSPs)). In this sense, one or more processors 146 may comprise any means configured to execute algorithms and / or instructions (e.g., program instructions stored in memory). In one embodiment, one or more processors 146 may embody a desktop computer, host computer system, workstation, graphics computer, parallel processor, networked computer, or any other computer system configured to execute a program (which is configured to operate or in conjunction with the superimposed metering system 100), as described throughout this disclosure. Furthermore, different subsystems of the superimposed metering system 100 may include processors or logic elements suitable for performing at least a portion of the steps described in this disclosure. Therefore, the above description should not be construed as limiting the embodiments of this disclosure but is merely illustrative. Furthermore, the steps described throughout this disclosure may be performed by a single controller or alternatively by multiple controllers. Additionally, controller 144 may comprise one or more controllers housed within a common housing or multiple housings. In this manner, any controller or combination of controllers can be individually packaged as a module suitable for integration into the overlay metering system 100.

[0107] Memory device 148 may comprise any storage medium known in the art suitable for storing program instructions executable by one or more associated processors 146. For example, memory device 148 may comprise a non-transitory memory medium. By another example, memory device 148 may comprise (but is not limited to) read-only memory (ROM), random access memory (RAM), magnetic or optical memory devices (e.g., magnetic disks), magnetic tape, solid-state drives, and the like. It should be further noted that memory device 148 may be housed together with one or more processors 146 in a common controller housing. In one embodiment, memory device 148 may be remotely located relative to the physical location of one or more processors 146 and controller 144. For example, one or more processors 146 of controller 144 may access remote memory (e.g., a server) accessible via a network (e.g., the Internet, an intranet, and the like).

[0108] In this manner, controller 144 may (e.g., via control signals) guide or receive data from multi-column stacking metrology tool 102 or any component thereof. Controller 144 may be further configured to perform any of the various process steps described throughout this disclosure, such as (but not limited to) guiding column positioning subsystem 112 to adjust the position of measuring column 104, guiding sample positioning system 114 to adjust the position of sample 108, or receiving detection signals associated with metrology measurements from one or more detectors 110, generating stacked measurements based on detection signals from detectors 110, generating calibrable items for one or more additional tools based on stacked measurements, or calibrating at least one measuring column 104 using stacked measurements from at least one additional measuring column 104.

[0109] In another embodiment, the overlay metering system 100 includes a user interface 150 communicatively coupled to the controller 144. In one embodiment, the user interface 150 may include (but is not limited to) one or more desktop computers, laptop computers, tablet computers, and the like. In another embodiment, the user interface 150 includes a display for displaying data from the overlay metering system 100 to a user. The display of the user interface 150 may include any display known in the art. For example, the display may include (but is not limited to) a liquid crystal display (LCD), an organic light-emitting diode (OLED) based display, or a CRT display. Those skilled in the art will recognize that any display device capable of being integrated with the user interface 150 is suitable for embodiments of this disclosure. In another embodiment, a user may input selections and / or instructions in response to data displayed to the user via a user input device of the user interface 150.

[0110] Figure 6 This is a flowchart illustrating the steps performed in a method 600 for multi-column metrology according to one or more embodiments of the present disclosure. Applicants should note that the embodiments and implementation techniques previously described herein in the context of the overlay metrology system 100 should be interpreted as extending to method 600. However, it should be further noted that method 600 is not limited to the architecture of the overlay metrology system 100.

[0111] In one embodiment, method 600 includes step 602 of providing multiplexed illumination to two or more measurement posts configured to simultaneously detect two or more measurement regions on a sample containing multiple measurement targets. For example, a particular measurement post may include an illumination subsystem for directing illumination from at least one of one or more illumination sources to the sample, a light-collecting subsystem including a light-collecting lens configured to collect measurement signals from the sample and direct the measurement signals to one or more detectors, and a post positioning subsystem configured to adjust the position of the light-collecting lens in a transverse plane parallel to the sample plane for measurement, wherein the measurement region of the particular measurement post is defined by the field of view of the light-collecting lens and the extent of the positioning system in the transverse plane.

[0112] In another embodiment, method 600 includes step 604 of directing illumination light to a metrological target within the measurement field of view of two or more measurement columns. In another embodiment, method 600 includes step 606 of collecting multiplexed measurement signals from two or more measurement columns. For example, the measurement signals may be multiplexed based on any of one or more parameters, including (but not limited to) wavelength, polarization, or time characteristics. Furthermore, measurement signals may be multiplexed in various ways. In one example, the measurement signals may be multiplexed after measurement (e.g., via one or more polarizers, one or more delay lines, or the like). In another example, multiplexing illumination light directed to two or more measurement columns results in similar multiplexing of the measurement signals. In another embodiment, method 600 includes step 608 of detecting the multiplexed measurement signals on one or more detectors. In another embodiment, method 600 includes step 610 of generating metrological data for the metrological target based on the detected measurement signals. For example, the metrological data may include (but is not limited to) superimposed metrological data.

[0113] Figure 7 This is a flowchart illustrating the steps performed in a method 700 for self-calibration of a multi-column metrology tool according to one or more embodiments of the present disclosure. Applicants should note that the embodiments and implementation techniques previously described herein in the context of the superimposed metrology system 100 should be interpreted as extending to method 700. However, it should be further noted that method 700 is not limited to the architecture of the superimposed metrology system 100.

[0114] This document should consider that multi-column metrology tools (e.g., but not limited to, multi-column stacked metrology tool 102, which comprises at least two measurement columns 104 with different measurement accuracies (or other characteristics)) can provide self-calibrated metrology data. Specifically, metrology data from one measurement column 104 can be used to calibrate and / or train another measurement column 104. For example, it may be that measurement columns 104 utilizing different types of illumination sources 106 can naturally exhibit different measurement characteristics, such as accuracy or processing power. For instance, a measurement column 104 based on X-ray, EUV, or particle beam illumination 134 may generally (but not always) provide higher measurement accuracy than a measurement column 104 based on visible or IR illumination 134, but with lower processing power. However, a higher-processing-power measurement column 104 can be calibrated to provide improved accuracy using metrology data from a higher-accuracy measurement column 104.

[0115] In one embodiment, method 700 includes step 702 of generating a first set of calibration measurements on a sample using one or more calibration measurement columns of a multi-column metrology tool. In another embodiment, method 700 includes step 704 of generating a second set of calibration measurements on a sample using one or more test measurement columns of a multi-column metrology tool. For example, one or more test measurement columns may provide measurement accuracy different from one or more calibration columns, wherein different measurement accuracies may be (but need not be) results obtained using different illumination sources 106.

[0116] However, it should be understood that the terms "test measurement column" and "calibration measurement column" are provided herein for illustrative purposes only and should not be construed as restrictive. Rather, any or all of the measurement columns 104 may be used for any desired purpose, including runtime measurements, calibration of other measurement columns 104, or combinations thereof. In this way, for clarity, the terms "test measurement column" and "calibration measurement column" are used herein to refer to different subsets of the measurement columns 104 used for self-calibration.

[0117] In another embodiment, method 700 includes step 706 of calibrating one or more test measurement columns based on a first and second set of calibration measurements. In another embodiment, method 700 includes step 708 of using one or more test measurement columns to generate one or more calibrated measurements that differ from one or more calibration targets.

[0118] Step 706, which involves calibrating one or more test measurement columns, can be implemented using various techniques. In one embodiment, step 706 includes identifying a correlation or pattern between the metrological measurements generated by both the test and calibration measurement columns and then training the test measurement column (or the controller 144 connected to any measurement column) to generate metrological data based on the correlation. In this way, the test measurement column (or the controller connected to any test measurement column) can use a combination of the measurement signals captured by the test measurement column and the correlation identified in step 706 to generate calibrated metrological data for a new test metrological target. Furthermore, this calibrated metrology can have higher accuracy than uncalibrated metrological data from the test measurement column and can be further generated based on the processing capabilities of the test measurement column.

[0119] Step 706 may involve several algorithms. For example, any technique known in the art (including, but not limited to, geometry engines, process modeling engines, or combinations thereof) can be used to model (parameterize) the metrological target. The use of process modeling is substantially described in U.S. Patent 10 / 769,320, published September 8, 2020, which is incorporated herein by reference in its entirety. The geometry engine may be (but does not need to be) implemented by AcuShape software (a product provided by KLA-Tex). By another example, the interaction between the illumination beam and the metrological target on the sample can be (but is not limited to) modeled using an electromagnetic (EM) solver. Furthermore, the EM solver can utilize any method known in the art, including (but not limited to) tightly coupled wave analysis (RCWA), finite element method analysis, moment analysis, surface integration techniques, volume integration techniques, or finite difference time-domain analysis.

[0120] Step 706 may further include analyzing the collected metrological data from the test or calibration measurement column using any data fitting and optimization techniques known in the field to apply the collected data to a model (including, but not limited to, linked libraries, fast reduction models, regression, machine learning algorithms (e.g., neural networks, support vector machines (SVM)), dimensionality reduction algorithms (e.g., principal component analysis (PCA), independent component analysis (ICA), locally linear embedding (LLE), and the like), sparse representations of the data (e.g., Fourier or wavelet transforms, Kalman filters, algorithms for facilitating matching from the same or different tool types, and the like)). For example, data collection and / or fitting may be (but does not need to be) performed by signal response metrology (SRM) (a product provided by KLA Corp).

[0121] Furthermore, various implementations of the algorithm may (but need not) be executed by a controller (e.g., controller 144) via firmware, software, or a field-programmable gate array (FPGA) or one or more other programmable optical elements.

[0122] Once the model is trained in step 706, step 708 may include implementing the model to provide calibrated metrological data for new metrological measurements of the new metrological target based on the test measurement column. Step 708 may incorporate any data fitting or optimization techniques known in the field to apply the collected metrological data from the new metrological target to the model. Continuing with the example provided in step 706, this may include (but is not limited to) library searching, regression analysis, implementing machine learning algorithms, support vector machines (SVMs), dimensionality reduction algorithms, or the like. For example, data collection and / or fitting may be (but does not need to be) performed by KLA-Tex Signal Response Metrology (SRM).

[0123] The objects described herein sometimes indicate that other components contain or are connected to other components. It should be understood that such depicted architectures are merely exemplary, and many other architectures can in fact be implemented to achieve the same functionality. Conceptually, any arrangement of components used to achieve the same functionality is effectively “associated” to achieve the desired functionality. Therefore, any two components combined herein to achieve a particular functionality can be considered “associated” with each other to achieve the desired functionality, regardless of the architecture or intermediate components. Similarly, any two such associated components can also be considered “connected” or “coupled” to each other to achieve the desired functionality, and any two components that can be suchly associated can also be considered “coupleable” to each other to achieve the desired functionality. Specific examples of coupleability include (but are not limited to) physically interactive and / or physically interactive components and / or wirelessly interactive and / or logically interactive components.

[0124] It is believed that this disclosure and many of its accompanying advantages will be understood from the foregoing description, and it will be appreciated that various changes can be made to the form, construction, and arrangement of the components without departing from the subject matter of the disclosure or sacrificing all its material advantages. The forms described are merely illustrative, and the appended claims are intended to cover and encompass such changes. Furthermore, it should be understood that the invention is defined by the appended claims.

Claims

1. A multi-column measurement tool, comprising: Two or more measurement columns distributed along a column direction, wherein the two or more measurement columns are configured to simultaneously probe two or more measurement regions on a sample containing multiple metrological targets, wherein the two or more measurement columns include one or more test measurement columns and one or more calibration measurement columns for calibrating the one or more test measurement columns, wherein a particular calibration measurement column or a particular test measurement column includes: A lighting subsystem configured to direct illumination from at least one of one or more lighting sources to the sample; A photon-collecting system comprising a photon-collecting lens configured to collect measurement signals from the sample and direct the measurement signals to one or more detectors; and A column positioning subsystem configured to adjust the position of the light-collecting lens in a transverse plane parallel to the sample plane for measurement, wherein the measurement area of ​​the specific calibration measurement column or the specific test measurement column is defined by the field of view of the light-collecting lens and the extent of the column positioning subsystem in the transverse plane; and A sample positioning subsystem is configured to scan the sample along a scanning path different from the column direction, wherein the scanning path positions a measurement target of the plurality of measurement targets within the measurement area of ​​the two or more measurement columns for measurement, wherein the column positioning subsystem of the two or more measurement columns positions the light-collecting lens of the two or more measurement columns to align the measurement target in the measurement area with the field of view of the light-collecting lens along the scanning path for measurement.

2. The multi-column measuring tool of claim 1, wherein the column positioning subsystem of at least one of the two or more measuring columns is further configured to adjust the position of the associated light-collecting lens along an axial direction normal to the transverse plane.

3. The multi-column metrology tool according to claim 2, wherein the column positioning subsystem further adjusts the position of the associated light-collecting lens along the axial direction to the target plane of the metrology for the measurement.

4. The multi-column metrology tool of claim 1, wherein at least one of the two or more measuring columns collects the measurement signals from two or more measuring planes and directs the measurement signals from the two or more measuring planes to at least one of the one or more detectors.

5. The multi-column metrology tool of claim 1, wherein the sample positioning subsystem is further configured to adjust the position of the sample along an axial direction normal to the transverse plane.

6. The multi-column metrology tool of claim 1, wherein the sample positioning subsystem includes a rotary stage for rotating the sample.

7. The multi-column measuring tool of claim 1, wherein at least one of the one or more detectors comprises a fixed detector positioned outside the two or more measuring columns.

8. The multi-column measuring tool of claim 7, wherein the measurement signals provided by at least two of the two or more measuring columns are multiplexed by one or more parameters.

9. The multi-column measuring tool according to claim 8, wherein the one or more parameters include: At least one of polarization, wavelength, or time.

10. The multi-column metrology tool of claim 8, wherein the fixed detector provides individual detector data associated with the multiplexed measurement signals from at least two of the two or more measurement columns.

11. The multi-column measuring tool according to claim 8, further comprising: A detection multiplexer configured to receive multiplexed measurement signals from at least two of the two or more measurement columns and generate two or more multiplexed measurement signals, wherein the detection multiplexer further distributes the two or more multiplexed measurement signals to the fixed detector.

12. The multi-column measuring tool of claim 8, wherein the illumination received by at least two of the two or more measuring columns is multiplexed by the one or more parameters.

13. The multi-column measuring tool of claim 7, wherein at least one of the two or more measuring columns guides the measuring signal via one or more optical fibers.

14. The multi-column measuring tool of claim 1, wherein at least one of the one or more detectors includes a movable detector positioned on at least one of the two or more measuring columns.

15. The multi-column measuring tool of claim 1, wherein at least one of the one or more lighting sources includes a fixed lighting source positioned outside the two or more measuring columns.

16. The multi-column measuring tool of claim 15, wherein at least two of the two or more measuring columns receive illumination from the fixed lighting source.

17. The multi-column measuring tool of claim 15, wherein at least one of the two or more measuring columns receives illumination from the fixed lighting source via one or more optical fibers.

18. The multi-column measuring tool of claim 1, wherein at least one of the one or more lighting sources includes a movable lighting source positioned on at least one of the two or more measuring columns.

19. The multi-column measuring tool according to claim 1, wherein at least one of the one or more lighting sources comprises an electromagnetic lighting source.

20. The multi-column metering tool of claim 1, wherein at least one of the one or more illumination sources comprises a particle beam illumination source.

21. The multi-column metrology tool of claim 1, wherein at least one of the two or more measuring columns is configured to perform a measurement on at least one of the plurality of metrological targets as the sample moves along the scanning path.

22. The multi-column metrology tool of claim 1, wherein at least one of the two or more measuring columns is configured to perform the measurement while the sample is fixed.

23. The multi-column metrology tool of claim 1, wherein the scanning path is linear, and wherein at least some of the plurality of metrological targets are linearly arranged to be measured by at least some of the two or more measuring columns as the sample is scanned along the scanning path.

24. The multi-column metrology tool of claim 1, wherein the spatial extent of the two or more measuring columns along the column direction corresponds to the size of the area to be measured on the sample.

25. The multi-column metrology tool of claim 1, wherein the size of the measurement area of ​​the one or more detectors along the column direction is summed to at least 10% of the size of the sample along the column direction.

26. The multi-column measuring tool according to claim 1, wherein the light-collecting lens comprises: Objective lens.

27. The multi-column measuring tool according to claim 1, wherein the measuring target includes: Specific measurement targets.

28. The multi-column measuring tool according to claim 1, wherein the measuring target includes: Device features on the sample.

29. The multi-column metering tool according to claim 1, wherein the metering target is formed by at least one of a post-development feature, a post-etching feature, or a post-cleaning feature.

30. The multi-column measuring tool according to claim 1, wherein the one or more illumination sources comprise: Two or more illumination sources, wherein one or more test measurement columns and one or more calibration measurement columns receive measurement signals from different illumination sources of the two or more illumination sources.

31. A multi-column measurement tool, comprising: Two or more measurement columns are distributed in a two-dimensional pattern, wherein the two or more measurement columns are configured to simultaneously probe two or more measurement regions on a sample containing multiple metrological targets, wherein the measurement regions of the two or more measurement columns are distributed to cover one or more selected regions of the sample containing at least some of the multiple metrological targets, wherein the two or more measurement columns include one or more test measurement columns and one or more calibration measurement columns for calibrating the one or more test measurement columns, wherein a particular calibration measurement column or a particular test measurement column includes: A lighting subsystem configured to direct illumination from at least one of one or more lighting sources to the sample; A photon-collecting system comprising a photon-collecting lens configured to collect measurement signals from the sample and direct the measurement signals to one or more detectors; and A column positioning subsystem configured to adjust the position of the light-collecting lens in a transverse plane parallel to the sample plane for measurement, wherein the measurement area of ​​the specific calibration measurement column or the specific test measurement column is defined by the field of view of the light-collecting lens and the range of the column positioning subsystem in the transverse plane. The column positioning subsystem of the two or more measuring columns adjusts the position of the corresponding light-collecting lens to align with the measuring target among the plurality of measuring targets in the corresponding measuring area.

32. The multi-column metrology tool of claim 31, wherein each of the two or more measuring columns covers a portion of the sample between a selected range of azimuth angles and a selected range of radius.

33. The multi-column metrology tool of claim 32, wherein the measurement areas of the two or more measuring columns cover the entire measurable area of ​​the sample containing the plurality of metrological targets.

34. The multi-column metrology tool of claim 32, wherein the measurement areas of the two or more measuring columns cover a portion of the measurable area of ​​the sample.

35. The multi-column measuring tool according to claim 33, further comprising: A sample positioning subsystem configured to rotate the sample, wherein the sample positioning subsystem rotates the sample to provide sampling of the entire measurable region of the sample.

36. The multi-column measuring tool according to claim 31, wherein the two-dimensional pattern comprises: Two-dimensional array.

37. The multi-column measuring tool of claim 31, wherein at least one of the one or more detectors comprises a fixed detector located outside the two or more measuring columns.

38. The multi-column measuring tool of claim 37, wherein the measurement signals provided by at least two of the two or more measuring columns are multiplexed by one or more parameters.

39. The multi-column measuring tool according to claim 38, wherein the one or more parameters include: At least one of polarization, wavelength, or time.

40. The multi-column metrology tool of claim 38, wherein the fixed detector provides individual detector data associated with the multiplexed measurement signals from at least two of the two or more measurement columns.

41. The multi-column measuring tool according to claim 38, further comprising: A detection multiplexer configured to receive multiplexed measurement signals from at least two of the two or more measurement columns and generate two or more multiplexed measurement signals, wherein the detection multiplexer further distributes the two or more multiplexed measurement signals to the fixed detector.

42. The multi-column measuring tool of claim 38, wherein the illumination received by at least two of the two or more measuring columns is multiplexed by the one or more parameters.

43. The multi-column measuring tool of claim 37, wherein at least one of the two or more measuring columns guides the measuring signal via one or more optical fibers.

44. The multi-column measuring tool of claim 31, wherein at least one of the one or more detectors includes a movable detector positioned on at least one of the two or more measuring columns.

45. The multi-column measuring tool of claim 31, wherein at least one of the one or more illumination sources includes a fixed illumination source positioned outside the two or more measuring columns.

46. ​​The multi-column measuring tool of claim 45, wherein at least two of the two or more measuring columns receive illumination from the fixed lighting source.

47. The multi-column measuring tool of claim 45, wherein at least one of the two or more measuring columns receives illumination from the fixed lighting source via one or more optical fibers.

48. The multi-column measuring tool of claim 31, wherein at least one of the one or more illumination sources includes a movable illumination source positioned on at least one of the two or more measuring columns.

49. The multi-column measuring tool according to claim 31, wherein at least one of the one or more lighting sources includes an electromagnetic lighting source.

50. The multi-column metering tool of claim 31, wherein at least one of the one or more illumination sources comprises a particle beam illumination source.

51. The multi-column measuring tool according to claim 31, wherein the light-collecting lens comprises: Objective lens.

52. The multi-column measuring tool according to claim 31, wherein the measuring target includes: Specific measurement targets.

53. The multi-column measuring tool according to claim 31, wherein the measuring target includes: Device features on the sample.

54. The multi-column metrology tool of claim 31, wherein the metrology target is formed by at least one of a post-development feature, a post-etching feature, or a post-cleaning feature.

55. The multi-column measuring tool according to claim 31, wherein the one or more illumination sources comprise: Two or more illumination sources, wherein one or more test measurement columns and one or more calibration measurement columns receive measurement signals from different illumination sources of the two or more illumination sources.

56. A multi-column metrology method, comprising: Illumination is provided to two or more measurement columns, wherein the two or more measurement columns are configured to simultaneously probe two or more measurement regions on a sample containing multiple metrological targets, wherein the two or more measurement columns include one or more test measurement columns and one or more calibration measurement columns for calibrating the one or more test measurement columns, wherein a particular calibration measurement column or a particular test measurement column includes: A lighting subsystem configured to direct illumination from at least one of one or more lighting sources to the sample; A photon-collecting system comprising a photon-collecting lens configured to collect measurement signals from the sample and direct the measurement signals to one or more detectors; and A column positioning subsystem configured to adjust the position of the light-collecting lens in a transverse plane parallel to the sample plane for measurement, wherein the measurement area of ​​the specific calibration measurement column or the specific test measurement column is defined by the field of view of the light-collecting lens and the range of the column positioning subsystem in the transverse plane. The illumination light is directed to the measurement target within the measurement field of view of the two or more measuring columns; Multiplexed measurement signals are collected by the two or more measurement columns; The multiplexed measurement signal is detected on one or more detectors; and Measurement data for the measurement target is generated based on the detected measurement signal.

57. The multi-column measurement method of claim 56, wherein the multiplexed measurement signal provided by at least two of the two or more measurement columns is multiplexed by one or more parameters.

58. The multi-column metrology method of claim 57, wherein the multiplexed measurement signal provided by at least two of the two or more measurement columns is multiplexed by at least one of polarization, wavelength, or time.

59. A multi-column metrology method, comprising: The first set of calibration measurements on a sample is generated using one or more calibration measurement columns of a multi-column metrology tool for one or more calibration targets. A second set of calibration measurements is generated using one or more test measurement columns of the multi-column metrology tool to produce the one or more calibration targets, wherein the one or more test measurement columns provide measurement accuracy different from that of the one or more calibration columns, wherein a specific calibration measurement column or a specific test measurement column includes: A lighting subsystem configured to direct illumination from at least one of one or more lighting sources to the sample; A photon-collecting system comprising a photon-collecting lens configured to collect measurement signals from the sample and direct the measurement signals to one or more detectors; and A column positioning subsystem configured to adjust the position of the light-collecting lens in a transverse plane parallel to the sample plane for measurement, wherein the measurement area of ​​a particular calibration measurement column or a particular test measurement column is defined by the field of view of the light-collecting lens and the range of the column positioning subsystem in the transverse plane. Calibrate one or more test measurement columns based on the first and second sets of calibration measurements; and The one or more test measurement columns are used to generate one or more calibrated measurements of one or more test targets that are different from the one or more calibration targets.

60. The multi-column metering method according to claim 59, wherein the one or more lighting sources comprise: Two or more illumination sources, wherein one or more test measurement columns and one or more calibration measurement columns receive measurement signals from different illumination sources of the two or more illumination sources.

61. The multi-column metrology method according to claim 59, wherein calibrating the one or more test measurement columns based on the first and second sets of calibration measurements comprises: Identify the correlation between the first and second sets of calibration measurements for the one or more test targets; and The one or more test measurement columns are trained based on the correlation to generate metrological measurements.

Images