Methods and related systems for collecting multidimensional datasets

Abstract

This document provides a method for collecting multidimensional datasets and related systems. [Solution] In one example, the method includes recording multiple data frames by performing test position measurements at multiple sample test locations and recording response signals. Each test position measurement is characterized by a phase delay. For at least one sample test location, the test position measurement is performed with a phase delay that is repeated in discontinuous measurements. In another example, the test position measurement is performed at each sample test location such that a different phase delay is used at each of two or more different sample test locations. In yet another example, the CPM system is configured to direct an irradiation pulse of a charged particle beam to the sample test location, apply an excitation stimulus to the sample test location, and receive one or more response signals. The CPM system includes a controller programmed to perform one or more methods disclosed herein.

Description

[Technical Field]

[0001] This disclosure relates, in general, to methods and systems for collecting multidimensional datasets. More specifically, this disclosure relates to methods and systems for collecting datasets generated by charged particle microscopy systems across various spatial and temporal dimensions. [Background technology]

[0002] Transmission electron microscope systems can be used to study sample responses to excitation stimuli via continuous excitation and probing of the sample region. For example, if the sample response corresponds to a reversible process, the process can be studied via repeated continuous excitation-probe cycles at the sample test site. By varying the phase delay between excitation and probe irradiation, time-resolved measurements of the sample response at the probed site can be obtained. By repeating such measurements across the sample region, the collected dataset can be further expanded across the spatial dimensions of the probe region.

[0003] When performing ultrafast electron microscopy using repeated stroboscopic measurements, the signal acquired for each excitation-probe cycle can be very small. These small signals may require long exposure times and / or repeated measurements at a given sample test location to accumulate useful measurements. As a result, the total time required to acquire a sufficient signal across the entire probe area of ​​the sample can be undesirably long. In some cases, such long measurement durations may allow for undesirable spatial drift of the probe area before the measurement is complete. In other cases, such long measurement durations may result in wasted time by delaying the notification to the user that data has been acquired under conditions that render the data unusable. [Overview of the Initiative]

[0004] In a typical example, a method for collecting a dataset includes recording multiple data frames by performing a test position measurement at each of multiple sample test locations for each of the multiple data frames. Performing a test position measurement for each sample test location includes applying an excitation stimulus to the sample test location at a stimulation time, directing a charged particle beam to the sample test location at a probe time separated from the stimulation time by a phase delay, and recording one or more response signals generated through the interaction between the charged particle beam and the sample. For at least one repeatable sample test location, the method includes repeating the test position measurement with repeating phase delays in a discontinuous test position measurement.

[0005] In another typical example, a method for collecting a dataset includes recording a data frame by performing a test position measurement at each of several sample test locations. Performing a test position measurement for each sample test location includes applying an excitation stimulus to the sample test location at a stimulation time, directing a charged particle beam to the sample test location at a probe time separated from the stimulation time by a phase delay, and recording one or more response signals generated through the interaction between the charged particle beam and the sample. Recording a data frame includes performing a test position measurement at each sample test location so that a single phase delay is used at each sample test location, and performing a test position measurement with a different phase delay at each of two or more different sample test locations among several sample test locations.

[0006] Another typical example is charged particle microscopy. A microscope (CPM) system includes a charged particle emitter configured to generate a charged particle beam, an optical assembly configured to direct and focus the irradiation pulse of the charged particle beam to a sample test position on the sample positioned in the sample plane, an excitation source configured to apply an excitation stimulus to the sample test position, a detector subassembly configured to receive one or more response signals generated through the interaction between the irradiation pulse and the sample, and a controller. The controller includes a processor system and a memory containing instructions, which, when executed by the processor system, cause the CPM system to record multiple data frames by performing a test position measurement at each of the multiple sample test positions on the sample for each of the multiple data frames. Performing a test position measurement includes applying an excitation stimulus to the sample test position using the excitation source during the stimulation time, directing the irradiation pulse to the sample test position during the probe time which is separated from the stimulation time by a phase delay, and recording one or more response signals generated through the interaction between the charged particle beam and the sample. This method involves repeating the process of performing a test position measurement with a repeated phase delay in a discontinuous test position measurement for at least one repeatable sample test position.

[0007] The aforementioned and other objects, features, and advantages of the present invention will become more apparent from the following detailed description, which proceeds with reference to the accompanying drawings. [Brief explanation of the drawing]

[0008] [Figure 1] This is a schematic diagram of a CPM system as an example. [Figure 2] This is a diagram of a sequence of measurements that may be performed to record multiple data frames, as an example. [Figure 3] This is a diagram of a sequence of measurements that may be performed to record multiple data frames, as in another example. [Figure 4]This is a diagram of a sequence of measurements that may be performed to record multiple data frames, as in another example. [Figure 5] This flowchart shows a method for collecting a dataset using an example. [Figure 6] This is a schematic diagram of a computing system that may be used to carry out one or more methods of this disclosure, as an example. [Modes for carrying out the invention]

[0009] This disclosure relates to scanning electron microscopy. (microscope, SEM) system and / or scanning transmission electron microscope (scanning) This invention relates to methods for acquiring datasets, such as using charged particle microscopy (CPM) systems, including transmission electron microscope (STEM) systems. In particular, the methods disclosed herein can provide useful and / or actionable information more quickly than conventional methods. Such methods may be particularly useful, for example, when performing strobometric measurements in ultrafast electron microscopy analysis, which may require repeated collection of low-intensity signals across various spatial and / or temporal dimensions.

[0010] Transmission electron microscope A microscope (TEM) system can be used to study the sample response to an excitation stimulus through continuous excitation and probing of the sample region. For example, a test site on the sample can be excited with an excitation stimulus that is highly localized in time. Subsequent probing of the test site with an incident electron beam can yield various response signals that can be collected to characterize the sample response to the excitation stimulus. If the sample response corresponds to a reversible process, the phase delay can be varied to separate the excitation stimulus and the incidence of the electron beam probe on the sample and repeat the measurements to study the development of the sample response over a period of time.

[0011] Such time-resolved studies can be performed in ultrafast regimes, where the duration of each excitation stimulus, the duration of irradiation of the sample by the probe electron beam, and the phase delay separating such events must be controlled very carefully. For example, excitation stimuli and / or irradiation may be performed on a picosecond or femtosecond timescale and separated by a phase delay of nanoseconds to less than a femtosecond. As a result, the signals collected by the TEM system for each measurement may be very small, requiring repeated measurements for a given phase delay to accumulate enough data to obtain statistically meaningful measurements. However, such iterations can result in long total experimental times. For example, total exposure times of several seconds or even minutes may be required to collect enough data corresponding to a range of phase delays at a given test location.

[0012] This experiment duration can worsen further if the experiment is extended to probe multiple (e.g., grid) test locations on the sample while the TEM is operating as a STEM. For example, probing a grid of 512 × 512 sample test locations with a 100 ms stroboscopic experiment at each test location results in a total experiment time exceeding 7 hours. When each test location is probed sequentially in this manner, the representation (e.g., image) of the sample area being tested may only be available after the experiment is complete, during which time the experiment may be plagued by various adverse conditions. For example, effects such as sample drift relative to the charged particle beam, damage to the sample by the charged particle beam, and / or suboptimal measurement parameters may only become apparent after the experiment is complete, leading to wasted time if the collected data ultimately proves unusable.

[0013] The present disclosure is directed to methods for data collection that avoid such drawbacks. For example, such methods can provide the user with indicators of the state or soundness of an experiment while the experiment is in progress and / or can enable adjustment of various experimental parameters prior to the completion of the full experiment.

[0014] The present disclosure generally relates to examples where a data collection method is implemented in conjunction with the operation of a CPM system. In particular, the present disclosure describes various examples where the CPM system is an electron microscope system such as a scanning electron microscope (SEM) system and / or a STEM system where the charged particle beam is an electron beam. However, this is not necessary for all examples, and additionally, it is within the scope of the present disclosure that the methods of the present disclosure may be applied to any other system such as other charged particle microscope systems and / or optical systems.

[0015] As used herein, the term "experiment" as used to describe the operation of a microscope system on a sample is intended to refer to any set or sequence of applicable measurements recorded with variations in one or more experimental parameters through respective parameter ranges. The present disclosure generally relates to examples where an experiment includes stroboscopic excitation and measurement at each of a plurality of sample test positions and each of a range of phase delays. However, it should be understood that an experiment may also refer to a process that varies more or less than these parameters. As examples, additional parameters that can be varied during the course of an experiment include the focal plane of the charged particle beam, the beam current of the charged particle beam, and the like.

[0016] Figure 1 illustrates an example of a CPM system 100 which may be used in conjunction with the method of the present disclosure. As will be discussed below, the CPM system 100 may be described as representing an example of a SEM system and / or STEM system. As shown in Figure 1, the CPM system 100 includes a charged particle emitter 102 that generates a charged particle beam 104 and an optical assembly 106 that directs and / or focuses the charged particle beam 104 onto a sample test position 112 of a sample 110. In some examples, the charged particle emitter 102 is an electron emitter and the charged particle beam 104 is an electron beam. The sample 110 and / or sample test position 112 can be positioned within the sample plane 111. The optical assembly 106 may include and / or be any of a variety of optical elements for manipulating the charged particle beam 104, such as an irradiator and / or a condenser system, and may include any preferred combination of electrostatic lenses, magnetic lenses, deflectors, compensators, etc.

[0017] The CPM system 100 further includes a scanning coil 108 configured to scan the charged particle beam 104 over the sample 110, directing the charged particle beam 104 to any of the various sample test positions 112 on the sample 110. The scanning coil 108 may also be referred to as a deflection coil 108. In this disclosure, the charged particle beam 104 may be described as illuminating the sample test position 112 when the charged particle beam 104 is incident on the sample test position 112 and generates a response signal as described herein.

[0018] For simplicity, Figure 1 illustrates a portion of the charged particle beam 104 and the corresponding signal downstream of the sample 110 in the form of a continuous beam. However, it should be understood that this disclosure may also relate to the charged particle beam 104 and / or the corresponding generated signal that are pulsed and / or discretized in other ways.

[0019] As shown in Figure 1, the CPM system 100 includes an excitation source 120 configured to deliver and / or apply an excitation stimulus 122 to the sample test location 112. In some examples, the excitation source 120 includes and / or is a laser source, and the excitation stimulus 122 is a laser beam and / or laser pulse generated by the excitation source 120. In the example of Figure 1, the CPM system 100 includes one or more waveguides 124 (e.g., optical fibers) configured and / or arranged to deliver the excitation stimulus 122 toward and / or to the sample test location 112.

[0020] In some examples, the excitation source 120 is configured to apply an excitation stimulus 122 over a region of the sample 110 encompassing multiple sample test locations 112. For example, the excitation stimulus 122 may be applied over a region of the sample 110 encompassing multiple sample test locations 112 to be measured in a given experiment, or all of the sample test locations 112. Additionally or alternatively, the excitation stimulus 122 may be applied to a portion of the sample 110 that does not encompass one or more of the sample test locations 112 to be measured. Thus, in various examples, the CPM system 100 may be configured so that the charged particle beam 104 is scanned over the sample 110 without scanning the excitation stimulus 122 over the sample 110 in a similar manner as the experiment moves to a new sample test location 112.

[0021] Each sample test location 112 can be defined in any of the following ways. For example, each sample test location 112 may refer to a localized location or point on the sample 110 (e.g., on the upper surface of the sample 110). In such an example, the sample test area may include a grid of spaced-out sample test locations 112. In such an example, the charged particle beam 104 may be focused toward each sample test location 112 and incident upon the sample 110 with a beam width encompassing the target sample test location 112. In another example, each sample test location 112 may refer to a two-dimensional region on the sample 110 (e.g., on the upper surface of the sample 110) such that adjacent sample test locations 112 are directly adjacent to each other. In such an example, the charged particle beam 104 may be focused toward each sample test location 112 with a beam width encompassing the sample test location 112. In all such examples, the sample test locations 112 may be additionally or alternatively referred to as pixels 112 and / or sample pixels 112.

[0022] This disclosure generally relates to an example where the excitation stimulus 122 is a pulsed laser beam, but this is not required in all examples. In other examples, the excitation source 120 may be configured to deliver any other suitable excitation to the sample test location 112, either additionally or alternatively. For example, the excitation stimulus 122 may include and / or be a mechanical stimulus, a thermal stimulus, an electromagnetic stimulus (e.g., non-laser light), etc.

[0023] When the sample test position 112 is irradiated by the charged particle beam 104, the sample 110 can obtain various response signals, which may be detected and / or measured by various methods. The CPM system 100 may include a detector subassembly 130 comprising one or more detectors for measuring such response signals. For example, as shown in Figure 1, the detector subassembly 130 may include a bright-field electron detector 132 configured to record a bright-field signal 134 emitted by the sample 110, an annular bright-field electron detector (e.g., bright-field electron detector 132) configured to record an annular bright-field signal (e.g., at least a portion of the bright-field signal 134) emitted by the sample 110, an annular dark-field electron detector 136 configured to record an annular dark-field signal 138 emitted by the sample 110, and / or a high-angle annular dark-field electron detector 140 configured to record a high-angle annular dark-field signal 142 emitted by the sample 110. Additionally or alternatively, the detector subassembly 130 may include an electron energy loss spectroscopy module 144 configured to record an electron energy loss spectroscopy signal 146. In all such examples, the signal recorded by each detector may include, and / or be, electrons emitted downstream from the sample 110 as a result of the interaction between the charged particle beam 104 and the sample test position 112.

[0024] Additionally or alternatively, the detector subassembly 130 may include one or more electron detectors configured to record information regarding the spatial distribution of electrons emitted from the sample 110. For example, as shown in Figure 1, the detector subassembly 130 may include a pixel-type electron detector 148 comprising a plurality of (e.g., grid) detector pixels. Such a pixel-type electron detector 148 may be configured to produce a two-dimensional record of electrons emitted by the sample 110, such as an image of the spatial distribution of electrons. In some examples, the pixels of the pixel-type electron detector 148 may be configured to record the arrival time of electrons incident on the pixel, the energy of electrons incident on the pixel, and / or the total number of electrons incident on each pixel in a given time unit. In some examples, the pixel-type electron detector 148 may be configured to record a diffraction signal 150 (e.g., a diffraction pattern) emitted by the sample 110. In particular, in the example of Figure 1, the diffraction signal 150 represents a focused beam electron diffraction signal. Additionally or alternatively, the pixel-type electron detector 148 may be configured to record any other preferred form of electron signal emitted from the sample 110.

[0025] As another example, the detector subassembly 130 may include a segmented electron detector 152 having multiple detector segments. In such an example, the segmented electron detector 152 may be configured to record a differential phase contrast signal 154 emitted from the sample 110.

[0026] The detector subassembly 130 may also include one or more detectors that detect signals emitted upstream as a result of the interaction between the charged particle beam 104 and the sample test position 112. The use of such detectors may correspond to examples where the CPM system 100 includes and / or is a SEM, and / or where the CPM system 100 includes and / or is a STEM. For example, as shown in Figure 1, the detector subassembly 130 may include a backscatter electron detector 172 configured to record a backscatter electron signal 174 emitted by the sample 110, and / or a secondary electron detector 176 configured to detect a backscatter electron signal 178 emitted by the sample 110.

[0027] In some examples, as shown in Figure 1, the signal emitted from the sample 110 may additionally or alternatively include electromagnetic radiation such as an X-ray signal 158. Therefore, the detector subassembly 130 may include an X-ray detector 156 configured to detect the X-ray signal 158. The X-ray signal 158 may include and / or an energy-dispersive X-ray spectroscopic signal.

[0028] Various detectors and components of the detector subassembly 130 are provided as non-limiting examples, and it should be understood that the CPM system 100 may include more or fewer detector components than those considered herein. It should be further understood that the CPM system 100 may include and / or use any preferred combination of such detector components.

[0029] As shown in Figure 1, the CPM system 100 may additionally include a controller 160 configured and / or programmed to operate various components of the CPM system 100 as described herein. For example, the controller 160 may include a processor system 162 and a memory 164 for storing instructions, which, when executed by the processor system 162, cause the controller 160 and / or the CPM system 100 to perform any applicable method disclosed herein. The CPM system 100 may additionally include a user input device 166 for receiving input from a user and / or a display device 168 for visually displaying information to the user.

[0030] The CPM system 100 may be configured to control the time at which the charged particle beam 104 and the excitation stimulus 122 are incident on the sample test position 112 by any of the following methods. The time interval separating the incident time of the excitation stimulus 122 to the sample test position 112 from the incident time of the irradiated charged particle beam 104 may be referred to herein as the phase delay and / or time delay.

[0031] As described herein, the excitation stimulus 122 and the charged particle beam 104 may each be incident on the sample test position 112 for a very short but non-zero duration. For example, the excitation stimulus 122 may include and / or be a pulse of laser light, and the charged particle beam 104 may be incident on the sample test position 112 in the form of pulses and / or columns of charged particles (e.g., electrons). Thus, the excitation stimulus 122 (and / or a portion thereof) incident on the sample test position 112 for a given measurement may be referred to herein as the excitation pulse 122. Similarly, a portion of the charged particle beam 104 incident on the sample test position 112 for a given measurement may be referred to as the irradiation pulse 105.

[0032] In some examples, each excitation stimulus 122 is incident on the sample 110 for a duration of less than 1 picosecond (ps). Additionally or alternatively, in some examples, each irradiation pulse 105 is incident on the sample 110 for a duration of less than 1 ps. In such examples, the excitation and / or irradiation of the sample test site 112 may be described as occurring on a femtosecond timescale.

[0033] The phase delay separating the excitation stimulus 122 from the incident of the charged particle beam 104 may be defined by any of the following methods. For example, the phase delay may be defined with respect to the time delays between the various incident portions of the excitation pulse 122 and the irradiation pulse 105 at the sample test position 112. As a more specific example, the phase delay may correspond to the time interval measured with respect to the time when each of the excitation pulse 122 and the irradiation pulse 105 has maximum intensity at the sample test position 112. Additionally or alternatively, the phase delay may correspond to the time delay measured with respect to the midpoint of each time interval in which each of the excitation pulse 122 and the irradiation pulse 105 is incident at the sample test position 112. As an additional example, the phase delay may correspond to the time interval measured with respect to the time when the excitation pulse 122 is first incident at the sample test position 112, the time when the excitation pulse 122 has maximum intensity at the sample test position 112, and / or the time when the excitation pulse 122 is last incident at the sample test position 112. Additionally or alternatively, the phase delay may correspond to a time interval measured with respect to the time when the irradiation pulse 105 first incident on the sample test position 112, the midpoint of the time interval in which the irradiation pulse 105 incident on the sample test position 112, and / or the time when the irradiation pulse 105 last incident on the sample test position 112.

[0034] The CPM system 100 may be configured to generate irradiation pulses 105 of the charged particle beam 104 by any of the following methods. For example, as shown in Figure 1, the CPM system 100 may include an RF cavity 170 configured to generate a pulsed charged particle beam through the interaction between one or more radio frequency (RF) standing waves and the passing charged particle beam (e.g., charged particle beam 104). Although not specifically illustrated in Figure 1, it should be understood that the RF cavity 170 may be located downstream of the charged particle emitter 102 in the intersecting plane of the charged particle beam 104.

[0035] In some examples, the RF cavity 170 may include input and output apertures that allow the charged particle beam 104 to traverse the RF cavity 170 so that the charged particle beam interacts with the RF waves established within the cavity. In other examples, a “chopping aperture” may be located away from the RF cavity 170. In such examples, the charged particle beam 104 can interact with the RF waves in the RF cavity 170 to obtain a periodic deflection of the charged particle beam 104 that causes the creation of an irradiation pulse 105 at the chopping aperture. In all such examples, spatial and / or temporal interactions between the aperture, the RF standing wave, and the charged particle beam 104 can form the irradiation pulse 105. In such examples, the RF waves can effectively move the charged particle beam across the output aperture, thereby emitting a pulse train of electrons that is directed toward the sample 110. An example of an RF cavity that may be used in conjunction with the CPM system 100 is disclosed in U.S. Patent No. 9,048,060, which is incorporated herein by reference for all purposes.

[0036] In another example, the irradiation pulse 105 may be generated at the charged particle emitter 102. For example, as shown in Figure 1, a portion of the laser pulse generated by the excitation source 120 may be transported (e.g., by a waveguide 124) toward the charged particle emitter 102 in the form of an emitter pulse 126. The emitter pulse 126 may then be incident on a portion of the charged particle emitter 102 to stimulate the emission of the charged particle beam 104 in the form of an irradiation pulse 105. Thus, in such an example, generating a series of excitation pulses 122 using the excitation source 120 can be operated to generate a corresponding series of irradiation pulses 105 using the charged particle emitter 102. In such an example, the charged particle emitter 102 may also be referred to as a photoelectron-induced charged particle emitter 102. In some such examples, the CPM system 100 additionally includes a variable irradiation delay line 128 configured to delay the transmission of the irradiation pulse 105 by a variable degree, in series with the waveguide 124 between the excitation source 120 and the charged particle emitter 102. Thus, in such examples, the phase delay at the sample test position 112 can be varied by varying the delay generated by the variable irradiation delay line 128 (for example, using a controller 160).

[0037] As yet another example, the pulsing of the charged particle beam 104 may be achieved via high-speed beam blanking, such as by using a beam blanker in the optical assembly 106.

[0038] In all such examples, the controller 160 may at least partially control the generation and / or pulsation of the charged particle beam 104. For example, the controller 160 may directly control the operation of the charged particle emitter 102 to obtain a continuous charged particle beam 104 and / or directly control the operation of the RF cavity 170 to obtain an irradiation pulse 105. In another example, the controller 160 may control the operation of the excitation source to generate an emitter pulse 126 used in conjunction with the photoelectron-induced charged particle emitter 102.

[0039] Figure 1 illustrates an example where an RF cavity 170 operates on an input charged particle beam 104 to generate an irradiation pulse 105, but it should be understood that the irradiation pulse 105 downstream of the RF cavity 170 may also be referred to (individually and / or collectively) as the charged particle beam 104. Similarly, in an example where a charged particle emitter 102 emits a charged particle beam 104 in the form of a series of irradiation pulses 105, such irradiation pulses 105 may also be referred to (individually and / or collectively) as the charged particle beam 104. Additionally, Figure 1 illustrates an example where the excitation stimulus 122 is the excitation pulse 122, but it should be understood that the excitation pulse 122 may also refer to a portion of the excitation stimulus that includes multiple such pulses.

[0040] In some examples, the pulsation of the charged particle beam 104 is synchronized with the scanning of the charged particle beam 104 (and / or irradiation pulses 105) over the sample 110. As described in more detail herein, such synchronization can result in an equal number of irradiation pulses 105 being delivered to each sample test position 112.

[0041] The CPM system 100 may be configured to control and / or measure the phase delay by any of the following methods. For example, as shown in Figure 1, the CPM system 100 may include a variable excitation delay line 129 in series with the waveguide 124 between the excitation source 120 and the sample 110, configured to delay the transmission of the excitation pulse 122 by a variable amount. In such an example, the delay generated by the variable excitation delay line 129 can be varied (e.g., using a controller 160) to cause a variation in the phase delay at the sample test position 112.

[0042] Additionally or alternatively, the phase delay may be controlled at least partially through the synchronization of the generation of the excitation pulse 122 with the operation of the RF cavity 170. For example, the controller 160 may be programmed and / or configured to coordinate the generation of the excitation pulse 122 by the excitation source 120 with the generation of the irradiation pulse 105 by the RF cavity 170, thereby delaying the irradiation pulse 105 relative to the excitation pulse 122 by the amount of the controlled phase delay.

[0043] This disclosure generally relates to an example in which the sample 110 is stroboprobed using individual irradiation pulses 105, but this is not required in all examples. For example, as considered above, a pixel electron detector 148 (and / or another component of the detector subassembly 130) may be configured to record the arrival time of electrons. In such an example, the charged particle beam 104 may be directed to the sample test position 112 over irradiation time intervals to obtain a response signal over corresponding time intervals. A portion of the response signal delayed by a given phase delay relative to the excitation stimulus 122 may then be identified and recorded as the response signal corresponding to that phase delay. Such a method may allow for the identification of a desired response signal with high accuracy. However, in some examples, the time required to reset the detector for subsequent measurements may be relatively long.

[0044] In this disclosure, references to performing test measurements with a specific phase delay, such as using appropriately timed irradiation pulses, may be understood to include examples in which the measured signal is extracted from an extended measurement duration as described above. That is, while this disclosure generally relates to examples in which the phase delay is controlled through the generation of irradiation pulses, the principles of this disclosure may equally apply to examples in which the phase delay corresponds to a selected portion of a timestamped continuous record.

[0045] The complete dataset generated through the experiments described herein may be described as a multidimensional dataset based on the number of parameters and / or dimensions characterizing each data point. For example, a given data point in the dataset may be characterized by each of the two spatial dimensions of the corresponding sample test position 112, the time dimension of the phase delay used to measure the data point, and the number of dimensions characterizing the measurement of the response signal.

[0046] As a more specific example, when the recorded response signals are measurements of two-dimensional diffraction patterns corresponding to each sample test position 112 (for example, recorded via a pixelated electron detector 148), the resulting dataset may be described as a five-dimensional dataset. If such a dataset is extended to include additional recording of high-angle annular dark-field signals using a high-angle annular dark-field electron detector 140, the resulting dataset may be described as a six-dimensional dataset. Thus, in various examples, the resulting dataset may be described as having 3+N dimensions, where N represents the total dimension of the recorded response signals.

[0047] In general, performing time-resolved experiments across a region of sample 110 using the CPM system 100 may involve the selection and / or adjustment of several variables that vary during the experiment. Examples of such variables include the location (e.g., coordinates) of the sample test position 112 probed in each test position measurement, the number of test position measurements performed at each sample test position 112 (and / or its sequence), and the phase delay used when each test position measurement is performed.

[0048] In some conventional examples, the experiment may be conducted by performing a series of test position measurements at each sample test position using several different phase delays prior to moving to the next sample test position. In such a “pixel-based” approach, a complete time-resolved dataset is collected at each sample test position, so the entire experiment may be completed when all sample test positions have been visited. However, such an approach may obscure and / or delay various indicators of the experiment's progress until the experiment is complete, at which point various errors in the experiment may finally become apparent. For example, if the sample drifts considerably with respect to the charged particle beam during the experiment, or if the selected sample test area contains defects, the resulting dataset revealed after a long experiment may be undesirable or unusable. Similarly, performing repeated measurements at each sample test position may result in increased damage to the sample by the charged particle beam, which may not become apparent until the experiment is completed long later. As another example, if various suboptimal experimental parameters (e.g., beam current, focal plane, degree of optical aberration, etc.) are used, the detection or correction of such problems may be delayed until the complete experiment is finished.

[0049] In contrast, the methods of the present disclosure can result in experimental procedures that provide useful and / or actionable information before the completion of a complete experiment. Thus, such methods can enable the acquisition of useful datasets without requiring the repeated execution of lengthy experiments. Such methods can also enable the generation of preliminary datasets and / or representations of a sample prior to the collection of a complete experimental dataset.

[0050] Figure 2 represents an example of a series of measurements that can be performed to obtain a dataset corresponding to the region of the sample. Figure 2 illustrates a series of data frames 200a - 200f that may be recorded to form at least a portion of the dataset. Each data frame 200a - 200f includes data corresponding to each of a plurality of sample test positions 202, each of which may be described with respect to coordinates (x k , y j ), where i = 1, 2, 3,..., m and j = 1, 2, 3,..., n.

[0051] As shown in Figure 2, each sample test position 202 of each data frame 200a - 200f may be characterized with respect to a phase delay Δ k , which is used to perform the corresponding test measurement. Each phase delay Δ k may be identified via an index k = 1, 2, 3,..., T, whereby the entire set of phase delays Δ k ranges from a minimum phase delay Δ1 to a maximum phase delay Δ T . In this way, the value T of the index may be understood to represent the resolution used to sample the phase delays within this range. As a simplified example, a range of phase delays characterized by a minimum phase delay of 0 s, a maximum phase delay of 100 ps, and T = 101 phase delays to be sampled may include phase delays Δ1 = 0 s, Δ2 = 1 ps, Δ3 = 2 ps,..., Δ T = 100 ps.

[0052] In various examples, it may be desirable to configure the set of phase delays Δ k to include phase delays corresponding to baseline test measurements, such as for determining whether the sample exhibits spatial drift and / or temporal drift (e.g., temporal instability) over the course of the experiment. For example, phase delay Δ kIt may be desirable to configure the set to include one or more negative phase delays (i.e., corresponding to the irradiation pulse arriving before the excitation pulse) to provide such baseline test measurements. Additionally or alternatively, the test measurement may be performed with zero delay between the excitation pulse and the irradiation pulse, which in some examples may represent such a baseline test measurement. In some examples, the baseline test measurement may correspond to a first phase delay (e.g., Δ1) that was tested, but this is not mandatory. Phase delay Δ k It should be understood that the set can include any set of phase delays, including sets that do not contain negative and / or zero phase delays.

[0053] In various examples, the phase delay is set to be equally spaced, for example, Δ for i=1,...,T-1. i+1 -Δ i The phase delay Δ is constant. k It may be desirable to construct a set of such data. In particular, probing a linear series of phase delays in this manner may be the most practically straightforward to implement and / or may provide evenly distributed sampling over time intervals of interest. However, this is not required in all examples. For example, it is also within the scope of this disclosure that the phase delays may be non-linearly distributed. As a more specific example, consider the phase delay Δ k It may be desirable to configure the set of phase delays to be logarithmically dispersed, such as probing the dynamics around the phase delay range of interest (e.g., near-zero phase delays) with higher resolution than longer phase delays further away from the range of interest. Additionally or alternatively, configuring the set of phase delays to be logarithmically dispersed can facilitate probing a wide range of time scales when the characteristic time scale of interest is not initially known.

[0054] This disclosure generally refers to the phase delay Δ kThe present example concerns testing a set of values ​​sequentially (e.g., in a sequence of increasing or decreasing values), but this is not necessary in all cases. For example, in some cases, it may be desirable to probe the phase delays in a non-sequential order, such as a random or pseudo-random order with respect to the phase delay values. In particular, such a configuration may facilitate distinguishing the actual dynamics of the sample response from irrelevant drifts in the signal that could otherwise be inadvertently correlated with sequentially tested phase delay values.

[0055] In the example in Figure 2, multiple data frames 200a to 200f are recorded sequentially, as indicated by the flow arrows. Additional data frames may also be recorded in this sequence between the data frames shown, as indicated by the ellipsis of the selected flow arrow. For example, any number of data frames similar to data frames 200a and 200b may be recorded between the recording of data frames 200a and 200b.

[0056] For each data frame 200a to 200f, a test position measurement is performed at each sample test position 202 by applying an excitation stimulus (e.g., excitation pulse 122 in Figure 1) to the sample test position during the stimulation time and directing a charged particle beam (e.g., irradiation pulse 105 in Figure 1) to the sample test position during the probe time. The probe time is separated from the stimulation time by a phase delay (e.g., assigned) corresponding to the sample test position being tested and the recorded data frame. Then, one or more response signals generated through the interaction between the charged particle beam and the sample are recorded using one or more components of the detector subassembly 130 in Figure 1, for example.

[0057] In some examples, one or more of the data frames 200a to 200f may be recorded by performing repeated sequential test position measurements at each sample test position (e.g., using multiple excitation pulses and / or multiple irradiation pulses) before proceeding to the next sample test position.

[0058] In other examples, one or more of the data frames 200a to 200f may be recorded by performing only a single test position measurement at each sample test position (for example, using a single excitation pulse and a single irradiation pulse) before proceeding to the next sample test position. In such examples, for all the test position measurements performed in a given data frame, consecutive test position measurements may be performed at different sample test positions.

[0059] In all examples, the number of consecutive test position measurements performed at each sample test position may be determined and / or controlled at least partially by synchronizing the scanning of the charged particle beam across the sample with the generation of excitation and / or irradiation pulses. For example, such synchronization can result in the same number (e.g., one or more) of excitation / irradiation pulse pairs being delivered to each sample test position.

[0060] In the example in Figure 2, data frame 200a is recorded at each sample test position 202 using the same (single) phase delay Δ1. In particular, in this example, multiple such data frames are recorded sequentially at each sample test position 202 using the same phase delay Δ1, with data frame 200a representing the first data frame in this sequence and data frame 200b representing the last data frame in this sequence.

[0061] Referring to a sequence of dataframes including dataframes 200a and 200b, each sample test position in each dataframe within this sequence may be described as a repeated sample test position. Specifically, in this disclosure, the term “repeated sample test position” refers to any sample test position in which different discontinuous test position measurements are performed with the same repeated phase delay. In this example, discontinuous test position measurements correspond to test position measurements performed in different dataframes.

[0062] However, it should be understood that this definition of repeated sample test positions does not rule out the possibility that such sample test positions may also be tested with the same repeated phase delay in consecutive test position measurements. This may be, for example, when multiple irradiation pulses are applied to each sample test position in a given data frame before proceeding to subsequent sample test positions in the data frame.

[0063] Data frames 200a-200b (and any similarly recorded intermediate data frames not shown in Figure 2) may be described herein as representing phase-redundant data frames. Specifically, as used herein, the term “phase-redundant data frame” may be used to refer to any set of data frames in which, for each sample test position, the test position measurement is performed with the same phase delay in each of the phase-redundant data frames. For example, referring to data frames 200a and 200b, the same phase delay is used for sample test position (x1, y1) in each data frame, the same phase delay is used for sample test position (x2, y1) in each data frame, and so on for all sample test positions. In other examples, as will be discussed in more detail below, a set of phase-redundant data frames may include data frames in which different phase delays are used for different sample test positions within the data frames. In the example in Figure 2, the sequence of phase-redundant data frames including data frames 200a and 200b may be referred to as the first set of phase-redundant data frames 210.

[0064] Following the recording of data frame 200b, data frame 200c may be recorded, using the same phase delay Δ2 at each sample test position 202. Multiple such data frames may then be recorded sequentially at each sample test position using the same phase delay Δ2, with data frame 200c representing the first data frame in this sequence and data frame 200d representing the last data frame in this sequence. Thus, data frames 200c-200d (and any similarly recorded intermediate data frames not shown in Figure 2) may also be described as representing a set of phase-redundant data frames. In particular, in this example, the sequence of phase-redundant data frames including data frames 200c and 200d may be referred to as a second set 220 of phase-redundant data frames.

[0065] This sequence considers each phase delay Δ k This may be repeated for each. In Figure 2, data frames 200e and 200f have the same final phase delay Δ T This represents the first and last data frames recorded using . Thus, data frames 200e~200f (and any similarly recorded intermediate data frames not shown in Figure 2) may also be described as representing a third set 230 of phase-redundant data frames. In the example in Figure 2, the third set 230 of phase-redundant data frames represents the last of T distinct sets of phase-redundant data frames to be recorded.

[0066] The number of phase-redundant data frames recorded for each phase delay being tested may be based at least in part on the number of test position measurements performed at each sample test position in each data frame. For example, for a given sample test position and a given phase delay to be tested, a complete characterization of the sample test position at that phase delay may require supplying at least a threshold irradiation flux to the sample test position via irradiation pulses. In other words, each irradiation pulse may produce a response signal that is too weak to be detected at a usable signal-to-noise ratio (SNR), thereby the usable signal can only be obtained by generating a series of response signals using a series of irradiation pulses until the total measurement signal has a sufficient SNR. The threshold irradiation flux can represent the total irradiation that yields such a total measurement signal.

[0067] The threshold irradiation flux may be distributed among various test-position measurements by any of the following methods. For example, increasing the number of test-position measurements performed at each sample test position within a given data frame can allow for a corresponding decrease in the number of phase-redundant data frames that need to be recorded (and vice versa).

[0068] Recording a relatively large number of phase-redundant data frames, where a relatively small number of test-position measurements (e.g., one test measurement) are performed at each sample test position, can result in each data frame being recorded over a relatively short period. In some examples, each data frame may not contain enough data to fully characterize the scanned area of ​​the sample (e.g., with a sufficient SNR), but each data frame (or a small set thereof) may still contain enough data to provide useful information about the experimental conditions.

[0069] For example, intermediate information about the experimental state may be obtained by analyzing any one (or more) of the data frames 200a to 200f shown in Figure 2. Examples of such intermediate information include information about the spatial drift of the sample during the experiment, whether the beam current of the charged particle beam is too low to produce a meaningful response signal, whether the beam current of the charged particle beam is too high to avoid damaging the charged particle beam, whether the charged particle beam is properly focused on the sample, and whether the scanning area of ​​the sample is suitable for testing. In some examples, such intermediate information may be obtained by combining two or more data frames (for example, by summing and / or integrating the measured response signals at each sample test position). For example, two or more phase-redundant data frames may be combined to obtain higher quality information about the response signal at each sample data position with each corresponding phase delay. In another example, two or more non-phase-redundant data frames may be combined to obtain intermediate information about other aspects of sample behavior, such as sample drift. In all such examples, the data frames analyzed to obtain such intermediate information may be referred to as test data frames.

[0070] In some cases, intermediate information can be included in the intermediate representation of the sample, represented as an intermediate representation, and / or derived from the intermediate representation. For example, one or more data frames may be recorded, rendered, and / or displayed as images representing the scanning region of the sample. Analysis of such images can yield intermediate information. For example, analysis of such images may yield information about the spatial drift of the sample, information about damaged areas of the sample, and / or information about whether different experimental parameters (e.g., beam current, focal position, etc.) are preferable.

[0071] In various examples, the intermediate representation may be described as such an image, even if the image is not graphically rendered and / or displayed. For example, the intermediate representation may be recorded and / or stored as a data file (e.g., an image data file) analyzed by a computer processor (e.g., controller 160). In other examples, the intermediate representation may be graphically displayed to the user, who can then derive meaningful information from the displayed representation and optionally adjust the experiment as appropriate.

[0072] In cases where analysis of one or more test data frames indicates that the experiment suffers from any of the shortcomings listed above, the experimental parameters may be adjusted as appropriate prior to completing the experiment. In some cases, such adjustments may be made, at least partially, in response to user input. For example, an intermediate representation may be displayed to the user (e.g., using the display device 168 in Figure 1), and the user may adjust one or more experimental parameters based on the intermediate representation (e.g., using the user input device 166 in Figure 1). Additionally or alternatively, the adjustments may be performed at least partially automatically by a controller 160 in Figure 1, for example.

[0073] The data contained in a set of phase-redundant dataframes may be combined and / or aggregated to obtain enhanced response signal measurements corresponding to each repeated sample test position. For example, for each sample test position, the recorded response signals measured in each dataframe of a given set of phase-redundant dataframes may collectively form an aggregated dataset corresponding to the repeated phase delays used in each such measurement. The aggregated dataset may then be reduced, for example, by summing and / or integrating the individual recorded response signals to obtain aggregated data points corresponding to selected sample test positions and corresponding phase delays. In this way, the aggregated data points may provide an improved SNR for the individual recorded response signals represented by each individual dataframe. An aggregated data point can be described as "reduced" with respect to an aggregated dataset in the sense that several data points in the aggregated dataset are condensed into a single corresponding aggregated data point. An aggregated data point may contain and / or refer to data of any dimension, such as (one-dimensional) intensity measurements and (two-dimensional) diffraction patterns.

[0074] In the example in Figure 2, various combinations of data frames may also be described as representing a set of phase-shift data frames. Specifically, as used herein, the term “phase-shift data frame” may be used to refer to any set of data frames in which, for each sample test position, the test position measurement is performed with a different phase delay in each of the phase-shift data frames. For example, referring to Figure 2, the phase delay used for each sample test position in data frame 200a is different from the phase delay used for the same sample test position in data frame 200c. Similarly, the phase delay used for each sample test position in data frame 200c is different from the phase delay used for the same sample test position in data frame 200e. Thus, data frames 200a, 200c, and 200e may be described as representing a set of phase-shift data frames.

[0075] Therefore, the example in Figure 2 may be illustrated as an example in which a multidimensional dataset is collected by recording multiple sequences of phase-redundant data frames, each sequence corresponding to a different phase delay used at each sample test location. Each sequence of phase-redundant data frames can then be aggregated to obtain aggregated data points corresponding to each sample test location and the phase delay used at that sample test location within each data frame. By repeating this procedure for each sequence of phase-redundant data frames, each sample test location can be associated with an aggregated data point corresponding to each phase delay within the range of phase delays tested.

[0076] In the example in Figure 2, each data frame 200a–200f is recorded so that each sample test position 202 represented within the data frame is tested with the same phase delay. However, this is not required in all examples. For example, Figure 3 illustrates another example of a measurement sequence that can be performed to obtain a dataset corresponding to a region of the sample. Figure 3 illustrates a series of data frames 300a–300f that may be recorded to form at least a portion of the dataset. Each data frame 300a–300f contains data corresponding to each of a plurality of sample test positions 302, each of which is in coordinate (x i ,y j The following can be explained regarding the equation, where i=1,2,3,...,m and j=1,2,3,...,n.

[0077] Similar to Figure 2, the multiple data frames 300a to 300f include a first set 310 of phase-redundant data frames containing data frames 300a and 300b, a second set 320 of phase-redundant data frames containing data frames 300c and 300d, and a third set 330 of phase-redundant data frames containing data frames 300e and 300f.

[0078] In the example in Figure 3, each data frame 300a to 300f contains a sample test position 302 in which test position measurements are performed with different phase delays. Specifically, in this example, each data frame represents a test position measurement performed with two different phase delays. In each data frame 300a to 300f, the sample test position (x i ,y j The (where i is an odd number) can also be described as forming a first positional subset, and the sample test position (x i ,y j The subset of positions (where i is an even number) can also be described as forming a second set of positions. (For simplicity, this example treats index m as an even integer, but this is not mandatory.)

[0079] In each data frame 300a–300f, each sample test position within the first position subset is measured with a first phase delay, and each sample test position within the second position subset is measured with a second phase delay. Within each set of phase-redundant data frames (e.g., within the first set 310, the second set 320, or the third set 330), the first phase delay is the same for each data frame within the set, and the second phase delay is the same for all data frames within the set.

[0080] However, when comparing data frames from different sets of phase-redundant data frames, it may be found that the first (or second) phase delay for one such data frame is different from the first (or second) phase delay for another such data frame. In this way, data frames selected from different sets of phase-redundant data frames may be described as forming a set of phase-varying data frames as described above.

[0081] For each data frame in the example in Figure 3, the sample test locations in the first position subset may be described as being interlaced with the sample test locations in the second position subset. The set of data captured in any such data frame (or aggregated data points of a set of phase-redundant data frames) may be described as analogous to the set of data collected in two different data frames, each of which is recorded with a single phase delay at each sample test location and with half the spatial resolution. Thus, by using different phase delays at different sample test locations (or subsets of sample test locations), information corresponding to multiple different phase delays can be obtained in a single scan of the sample region, with a trade-off of reduced spatial resolution. For example, it may be desirable to test multiple different phase delays using a rapid method to determine whether such phase delays are appropriate for the dynamic process being probed before conducting a full experiment. In such an example, the reduced spatial resolution that may result from interleaving phase delays using the method in Figure 3 may not be important for the information obtained to verify and / or calibrate experimental parameters in the early stages of the experiment.

[0082] Figure 3 illustrates an example where the first and second position subsets are interleaved with each other, but this is not mandatory. In other examples, the first and second position subsets may correspond to any other non-overlapping subsets of sample test locations. Additionally or alternatively, a sample test location may include any other suitable number (e.g., three, four, or more) of test location subsets with corresponding phase delays. A test location subset may contain the same number of sample test locations or a different number of sample test locations.

[0083] In various examples, a method in which each sample test position is associated with a corresponding phase delay within a given data frame may be described as representing the phase mapping of the data frames. Therefore, for example, every data frame in a given set of phase-redundant data frames may be described as being characterized by the same phase mapping. Similarly, each data frame in a given set of phase-variable data frames may be described as being characterized by a different phase mapping.

[0084] Figure 4 illustrates another example of a sequence of measurements that can be performed to obtain a dataset corresponding to a region of the sample. Figure 4 illustrates a series of data frames 400a–400d that may be recorded to form at least a portion of the dataset. Each data frame 400a–400d contains data corresponding to each of a plurality of sample test locations 402, each of which has coordinates (x i ,y j The following can be explained regarding the equation, where i=1,2,3,...,m and j=1,2,3,...,n.

[0085] In the example in Figure 4, each data frame 400a–400d is characterized by the same phase mapping. Therefore, data frames 400a–400d may be described as representing a set of phase-redundant data frames. Additionally, in this example, the phase mapping is characterized by the use of different phase delays at each sample test position 402.

[0086] In the example in Figure 4, each sample test location is tested at only a single phase delay; therefore, the resulting dataset does not contain the same information as in the examples in Figures 2 and 3, where each sample test location is tested at multiple different phase delays. However, capturing one or more data frames using the method in Figure 4 can still be beneficial, for example, to test a wide range of phase delays over a relatively short period. For instance, the range of phase delays used in each data frame 400a–400d may be broad enough to encompass dynamic processes occurring on an unknown timescale. In such cases, one or more of the data frames 400a–400d may provide indications of characteristic timescales (individually and / or collectively) that can be more accurately probed in subsequent experiments.

[0087] In another example, the measurement sequence shown in Figure 4 may be varied by varying one or more phase mappings among data frames 400a-400d so that each sample test position 402 is tested with different phase delays in two or more different data frames. For example, the phase mappings may be adjusted so that each data frame represents the same set of phase delays, and the set of phase delays is distributed among the sample test positions in a manner different from that used to obtain phase-varied data frames. In such an example, sufficient data may be obtained to form a complete experimental dataset by recording a sufficient number of such phase-varied data frames (and / or a sufficient number of phase-redundant data frames for each individual phase mapping). In some examples, the set of data frames in which a given sample test position is measured with the same phase delay may differ for each sample test position and / or each phase delay. Therefore, it may be desirable to assign metadata labels representing the data frame, sample test position, and / or phase delay corresponding to the recorded response signal to each recorded response signal. This may allow for the identification of all recorded response signals corresponding to a given sample test position and / or a given phase delay, regardless of the sequence in which the corresponding measurements were performed.

[0088] In the examples in Figures 2-4, flow arrows are provided to illustrate an example of a sequence in which the illustrated dataframes may be recorded. However, it should be understood that such a sequence is not mandatory, and an equivalent dataset may be obtained by recording the dataframes in any other sequence. Therefore, unless otherwise specified, any reference herein to recording a given number of dataframes does not require that such dataframes be recorded in a continuous sequence.

[0089] Figures 2–4 schematically illustrate an example in which locating measurements are performed at every sample test location for each data frame. However, this is not required in all examples. For example, it is also within the scope of this disclosure that one or more data frames may be recorded in a “sparse” manner in which locating measurements are performed at some, but not all, sample test locations. In some such examples, multiple data frames may be recorded in such a way that locating measurements are performed at each sample test location in some, but not all, of the data frames.

[0090] Additionally or alternatively, the set of sample test locations on which sample test location measurements are performed in at least one data frame may be loosely distributed within the sample region. In other words, in some examples, the set of sample test locations may be selected such that test location measurements are not performed in various regions of the sample adjacent to and / or between selected sample test locations.

[0091] In various examples, the phase delay may also be probed using sparse methods. For example, Figures 2–4 generally show examples where the phase delay is probed sequentially (e.g., between adjacent sample test locations within a given data frame and / or between the same sample test locations in sequentially recorded data frames), but this is not required in all examples. In other examples, as discussed above, the phase delay may be probed in a random or pseudo-random sequence within a given data frame and / or between sequentially recorded data frames.

[0092] Figure 5 is a flowchart illustrating an example of method 500 for collecting a dataset. Unless otherwise specified, each component, feature, attribute, etc. described herein with reference to method 500 may be understood to refer to and / or encompass similarly named components, features, attributes, etc. considered herein with reference to any of Figures 1 to 4. Method 500 and / or any preferred part thereof may be implemented by a computer processor system, such as by one or more processors of the controller 160 in Figure 1.

[0093] As shown in Figure 5, method 500 includes recording one or more data frames in 510. For each of the one or more data frames, recording the data frame in 510 may include performing a test position measurement at each of the multiple sample test positions in 516.

[0094] For each sample test position, performing a test position measurement in 516 may include applying an excitation stimulus to the sample test position in 522 during the stimulation time and directing a charged particle beam to the sample test position in 524 during the probe time. The probe time is separated from the stimulation time by the amount of phase delay. For each sample test position, performing a test position measurement in 516 may additionally include recording one or more response signals generated through the interaction between the charged particle beam and the sample in 526. The charged particle beam may include and / or be such a charged particle beam, such as the charged particle beam 104 generated by the CPM system 100 in Figure 1.

[0095] In 516, the measurement of multiple test locations may be performed using one of several methods. In some examples, the measurement of test locations in 516 is performed such that the multiple sample test locations form a two-dimensional grid of positions on the sample.

[0096] In some examples, in 516, the test position measurement is performed so that the test position measurement is synchronized with the scanning of the charged particle beam across the sample. Specifically, in some examples, method 500 includes scanning the charged particle beam across the sample to direct the charged particle beam to each sample test position and synchronizing the scanning of the charged particle beam with the performance of the test position measurement in 516. Such synchronization may be performed so that the same number of test position measurements are performed at each sample test position before proceeding to subsequent sample test positions. More specifically, in 524, directing the charged particle beam may include directing irradiation pulses to the sample test positions, and synchronizing may include directing the same number of irradiation pulses to each sample test position.

[0097] As discussed above in the context of Figure 1, applying an excitation stimulus at 522 may include applying an excitation stimulus to a region of the sample encompassing multiple sample test locations, such as all of the multiple sample test locations. In some examples, applying an excitation stimulus at 522 may include directing a laser pulse onto the sample, such as a femtosecond laser pulse incident on the sample for a duration of less than 1 ps.

[0098] In some examples, directing a charged particle beam in 524 involves directing a charged particle beam pulse (e.g., an irradiation pulse) to the sample test location. For example, the charged particle beam pulse may be incident on the sample for a duration of less than 1 ps.

[0099] Recording a response signal with 526 may include recording any of various signals using any of various detectors. For example, recording a response signal in 526 may include recording a bright-field signal and / or annular bright-field signal (e.g., using the bright-field electron detector 132 in Figure 1), recording an annular dark-field signal (e.g., using the annular dark-field electron detector 136 in Figure 1), recording a high-angle annular dark-field signal (e.g., using the high-angle annular dark-field electron detector 140 in Figure 1), recording a backscattered electron signal (e.g., using the backscattered electron detector 172 in Figure 1), recording a secondary electron signal (e.g., using the secondary electron detector 176 in Figure 1), recording an energy-dispersive X-ray spectroscopy signal (e.g., using the X-ray detector 156 in Figure 1), recording an electron energy-loss spectroscopy signal (e.g., using the electron energy-loss spectroscopy module 144 in Figure 1), recording a differential phase contrast signal (e.g., using the split-type electron detector 152 in Figure 1), and / or recording a focused beam electron diffraction signal (e.g., using the pixel-type electron detector 148 in Figure 1).

[0100] In various examples, recording a response signal in 526 involves recording signals corresponding to two or more different analytical methodologies, such as by using two or more separate detector devices. For example, the response signal recorded in each test position measurement may include an electron energy loss spectroscopy signal recorded by an electron energy loss spectroscopy module, and an annular signal recorded by an annular STEM detector (e.g., a bright-field electron detector, an annular dark-field electron detector, and / or a high-angle annular dark-field electron detector). In another example, the response signal recorded in each test position measurement may include an energy-dispersive X-ray spectroscopy signal recorded by an X-ray detector, and a backscatter electron signal recorded by a backscatter electron detector and / or a secondary electron signal recorded by a secondary electron detector. In yet another example, the response signal recorded in each test position measurement may include an electron diffraction pattern recorded by a pixel electron detector, and a high-angle annular dark-field signal recorded by a separate high-angle annular dark-field electron detector. Any other practical combination of signals and / or detectors is also within the scope of this disclosure. In such examples, the test position measurement may be described as a multimodal measurement. As a result, the dataset obtained from the implementation of Method 500 may have dimensions of 3 + N, where N represents the total dimension of the response signals collected at each test position measurement.

[0101] In some examples, method 500 includes repeating the process of performing a test position measurement in 516 with a repeated phase delay in a discontinuous test position measurement for at least one repeatable sample test position. Such discontinuous test position measurements may correspond to test position measurements performed while different data frames are being recorded. For example, referring to the first set 210 of phase-redundant data frames in Figure 2, each sample test position 202 may be described as representing such repeatable sample test positions, since each sample test position is tested with a repeated phase delay (in this case, Δ1) in a discontinuous measurement corresponding to a different data frame.

[0102] In some examples, recording a data frame at 510 involves repeating the process of performing a test position measurement at 516 at each sample test position multiple times for each data frame, before performing a test position measurement at each sample test position. For example, as described above, data corresponding to multiple irradiation pulses can be accumulated by performing repeated test position measurements for a given phase delay at a given sample test position.

[0103] Thus, the total irradiation flux required to obtain a signal with a sufficient SNR may be distributed among multiple consecutive test position measurements performed at a given sample test position with a given phase delay, and among multiple discontinuous test position measurements performed at a given sample test position for different data frames. As discussed above, distributing at least a portion of the total irradiation flux across different data frames can help to obtain useful information about the experimental conditions more quickly and / or preserve the integrity of the sample. In some examples, for each data frame, all pairs of consecutive test position measurements may be performed at different respective sample test positions.

[0104] In some examples, repeating the test measurement at 516, as discussed above in the context of Figure 2, may include performing multiple test position measurements at each sample test position with repeated phase delays to obtain an aggregated dataset corresponding to the repeated sample test positions and repeated phase delays. In such examples, method 500 may include reducing the aggregated dataset for each repeated sample test position and each repeated phase delay at 534.

[0105] Reducing the aggregated dataset in 534 can include combining the data within the aggregated dataset using one of several methods, such as summing and / or merging the aggregated datasets. For example, referring to the first set 210 of phase-redundant data frames in Figure 2, the aggregated dataset corresponding to each sample test position 202 can include all the response signals considered at the sample test position across all the data frames of the first set 210. In such an example, reducing the aggregated dataset in 534 can include summing and / or merging all the individual response signals to obtain a single reduced data point representing the response of the sample test position with repeated phase delays.

[0106] In some examples, repeating the test position measurement at 516 involves recording multiple repeated data frames having similar and / or identical measurement parameters. For example, as shown in Figure 5, recording a data frame at 510 may include recording multiple phase-redundant data frames at 512 as described above. In particular, for each sample test position among multiple sample test positions, the test position measurement is performed with the same phase delay for each data frame in the multiple phase-redundant data frames.

[0107] In some examples, method 500 additionally includes iterating the recording of phase-redundant data frames in 512 at each of several different phase delays. The sequence shown in Figure 2 represents an example of such a method, where each of the first set 210, second set 220, and third set 230 of phase-redundant data frames individually represents the result of each iteration of recording in 512. In this example, recording of phase-redundant data frames in 512 is iterated at different phase delays to generate a set of different sets of phase-redundant data frames.

[0108] In some examples, and as shown in Figure 5, recording a data frame at 510 includes recording multiple phase-shift data frames at 514 as described above. In particular, for each data frame within the multiple phase-shift data frames, the test position measurement is performed at each sample test position with a phase delay that corresponds to the data frame, which is different from the phase delay corresponding to each other data frame. As described above in the context of Figures 2 and 3, selected data frames taken from each of several different sets of phase-redundant data frames may be described as representing a set of phase-shift data frames.

[0109] In some examples, for at least one data frame, Method 500 includes performing a test position measurement with the same phase delay for each sample test position. For example, in the example in Figure 2, each of data frames 200a to 200f is recorded such that the same phase delay is used for all sample test positions within each data frame. In some such examples, Method 500 may include performing a test position measurement exactly once at each sample test position so that consecutive test position measurements are performed at different sample test positions. In other examples, Method 500 may include performing multiple test position measurements at each sample test position with a given phase delay before proceeding to subsequent sample test positions.

[0110] Additionally or alternatively, Method 500 may include performing test position measurements with different phase delays at each of two or more sample test positions within at least one data frame. For example, in the example in Figure 3, each of data frames 300a to 300f contains different sample test positions for which different phase delays are used.

[0111] More specifically, as discussed above in the context of Figure 3, the sample test positions in the data frame may be divided into (at least) a first position subset and a second position subset, each using different first and second phase delays. Thus, as shown in Figure 5, Method 500 may include, for at least one data frame, performing a test position measurement with a first phase delay at each sample test position in the first position subset in 518. Similarly, Method 500 may include, for the same data frame, performing a test position measurement with a second phase delay different from the first phase delay at each sample test position in the second position subset in 520. In various examples, Method 500 may similarly include using a different third phase delay in a third position subset, using a different fourth phase delay in a fourth position subset, and so on.

[0112] In some examples, recording a data frame with 510 involves performing a test position measurement at each sample test position such that a single phase delay is used for each (individual) sample test position for at least one data frame, and a different phase delay is used for each of two or more different sample test positions. The examples in Figures 3 and 4 may also be described as representing examples of such a method. In particular, different sample test positions corresponding to different phase delays may be selected from the first and second position subsets of the data frame in Figure 3. Similarly, different sample test positions corresponding to different phase delays may correspond to any two different sample test positions in any data frame in Figure 4.

[0113] In some examples, Method 500 may include analyzing one or more of the recorded data frames to obtain information about the state of the experiment being conducted before all data frames were recorded. In such examples, such data frames that may be analyzed in an intermediate stage of the Method may be referred to as one or more test data frames.

[0114] As shown in Figure 5, Method 500 may, following recording test data frames, include, in 528, analyzing one or more test frames to obtain intermediate information about the sample. In some examples, analyzing the data frames in 528 includes, in 530, generating an intermediate representation of the sample. The intermediate representation may be based at least partially on one or more of the test data frames. As considered above in the context of Figure 2, the intermediate representation may take any of a variety of forms, such as a data file analyzed by a computer processor and / or a graphical representation displayed to the user.

[0115] In some examples, intermediate information and / or intermediate representations can be used to update one or more aspects of the experimental procedure. For example, as shown in Figure 5, method 500 may additionally include, in 532, adjusting one or more measurement parameters of the charged particle microscope system (e.g., the CPM system 100 in Figure 1) on which method 500 is being performed. Adjusting the measurement parameters in 532 may be done at least in part on intermediate information and / or intermediate representations. Adjusting the measurement parameters in 532 may be done following the recording of the test data frame and prior to the recording of subsequent data frames.

[0116] In some cases, the adjustment of measurement parameters in 532 is performed at least partially automatically by a controller of the charged particle microscope system (e.g., controller 160). For example, an automatic comparison of intermediate representations corresponding to two different test data frames may indicate the degree to which the sample has spatially drifted, and the controller may automatically adjust the scanning of the charged particle beam to counteract the effects of such drift.

[0117] Additionally or alternatively, the adjustment of measurement parameters in 532 may be performed at least partially manually and / or in response to user input. For example, method 500 may include displaying intermediate information and / or intermediate representations to the user, who may then choose to adjust one or more experimental parameters based on the intermediate information.

[0118] Figure 6 and the following discussion are intended to provide a brief and general description of an exemplary computing environment in which the disclosed technology may be implemented. In particular, some or all parts of this computing environment may be used in conjunction with the above-described methods and apparatus to, for example, direct a charged particle beam and / or excitation stimulus to a sample test position, perform a test position measurement, and / or implement any part of the methods disclosed above.

[0119] Although not mandatory, the disclosed technologies are personal computers. This is described in the general context of computer executable instructions, such as program modules, executed by a computer (PC). Generally, a program module includes routines, programs, objects, components, data structures, etc., that perform a specific task or implement a specific abstract data type. Furthermore, the disclosed technology can be implemented using other computer system configurations, including handheld devices, tablets, multiprocessor systems, microprocessor-based or programmable consumer electronics, network PCs, minicomputers, mainframe computers, virtual machines, containerized applications, and Kubernetes clusters. The disclosed technology can also be practiced in a distributed computing environment where tasks are performed by remote processing devices linked through a communication network. In a distributed computing environment, program modules may reside in both local and remote memory storage devices. In some cases, such processing is provided in a CPM. The system of this disclosure can act as an image processor, as well as controlling image acquisition and providing a user interface.

[0120] Referring to Figure 6, an exemplary system for realizing the disclosed technology includes a general-purpose computing device in the form of an exemplary conventional PC 600, comprising one or more processing units 602, system memory 604, and a system bus 606 that connects various system components, including the system memory 604, to the one or more processing units 602. Each of the one or more processing units 602 may be additionally or alternatively referred to as a processor 602, and the one or more processing units 602 may collectively be referred to as a processor system. The system bus 606 may be one of several types of bus structures, including a memory bus or memory controller, peripheral bus, and local bus, using any of various bus architectures. The exemplary system memory 604 includes read-only memory (ROM) 608 and random-access memory (ROM) This includes memory (RAM) 610. ROM 608 stores a basic input / output system (BIOS) 612 containing basic routines that facilitate the transfer of information between elements within PC 600. In various examples, PC 600 (and / or one or more of its components) may be additionally or alternatively referred to as the controller. PC 600 may represent an example of at least a portion of the controller 160 in Figure 1.

[0121] An exemplary PC600 further includes one or more storage devices 630, such as a hard disk drive for reading from and writing to a hard disk, a magnetic disk drive for reading from and writing to a removable magnetic disk, and an optical disk drive for reading from and writing to a removable optical disk (such as a CD-ROM or other optical medium). Such storage devices can be connected to the system bus 606 by hard disk drive interfaces, magnetic disk drive interfaces, and optical drive interfaces, respectively. The drives and their associated computer-readable media provide non-volatile storage of computer-readable instructions, data structures, program modules, and other data for the PC600. Other types of computer-readable media capable of storing data accessible by the PC, such as magnetic cassettes, flash memory cards, solid-state drives, digital video discs, CDs, DVDs, RAM, and ROMs, may also be used in the exemplary operating environment.

[0122] Some program modules may be stored in a storage device 630 containing an operating system, multiple operating systems, a virtual operating system, one or more application programs, other program modules, and / or program data. In some examples, one or more aspects of the methods disclosed herein may be programmed, implemented, encoded, trained, and / or optionally transferred to program modules via machine learning, neural networks, artificial intelligence, and the like.

[0123] An exemplary PC600 may include various devices configured for a user interface. For example, a user may input commands and information to the PC600 through one or more input devices 640, such as a keyboard and / or a pointing device such as a mouse. For example, a user may input a command to start image acquisition and / or to start one or more methods disclosed herein. Other input devices may include a digital camera, microphone, joystick, gamepad, buttons, dials, satellite receiver, scanner, etc. In some examples, several such input devices may be integrated into a single user interface device, which may be commonly used in conjunction with a CPM system. These and other input devices are often connected to one or more processing units 602 through a serial port interface coupled to the system bus 606, but may also be connected by other interfaces, such as a parallel port, game port, Universal Serial Bus (USB), or wired or wireless network connection. Monitor 646 or other types of display devices may also be connected to the system bus 606 via an interface such as a video adapter and may display one or more images of a sample or specimen, for example, before, after, and / or during the implementation of one or more methods disclosed herein. Monitor 646 may also be used to select sections for processing or specific image alignment and alignment procedures, such as correlation, feature identification, and preview area selection or other image selection. Other peripheral output devices such as speakers and printers (not shown) may be included. Input device 640 may represent an example of user input device 166 in Figure 1. Additionally or alternatively, monitor 646 may represent an example of display device 168 in Figure 1.

[0124] The PC600 can operate in a network environment using logical connections to one or more remote computers, such as remote computer 660. In some examples, this includes one or more network or communication connections 650. The remote computer 660 may be another PC, server, router, network PC, and / or peer device, or other common network node, and typically includes many or all of the elements described above in relation to the PC600, except that only the memory storage device 862 is illustrated in Figure 6. The personal computer 600 and / or remote computer 660 are connected to a local area network (LAN) and a wide area network (wide It can connect to an area network (WAN). Such networking environments are common in offices, enterprise-wide computer networks, intranets, and the internet.

[0125] As shown in Figure 6, memory 690 (or a portion of this memory or other memory) can store processor-executable instructions for beam focus control, beam deflector control, pattern recognition and analysis (e.g., detecting and / or characterizing the drift of a sample relative to a charged particle beam). Such processor-executable instructions may additionally or alternatively include instructions for performing various calculations and / or various measurement routines, such as those described herein. For example, when such processor-executable instructions are executed by the processor system, they can cause PC600 and / or other components (e.g., any preferred component of the CPM system 100 in Figure 1) to perform any of the methods disclosed herein. In some examples, processor-executable instructions may generate a display image (e.g., an intermediate representation of the sample), process a preview image, and / or acquire additional images.

[0126] General Considerations As used in this application and claims, the singular forms "a," "an," and "the" include the plural form unless otherwise explicitly indicated. Additionally, the term "includes" means "comprises." Furthermore, the term "coupled" does not exclude the presence of intermediate elements between coupled items.

[0127] Unless otherwise specified, as used herein, the term “substantially” means any value and / or characteristic listed, as well as any value and / or characteristic that is at least 75% of any value and / or characteristic listed. Equivalently, the term “substantially” means any value and / or characteristic listed, as well as any value and / or characteristic that differs from any value and / or characteristic by a maximum of 25%. For example, “substantially equal” means quantities that are exactly equal, as well as quantities that differ from each other by a maximum of 25%.

[0128] The systems, apparatus, and methods described herein should not be construed as limiting. Rather, this disclosure covers all novel and non-obvious features and aspects of the various disclosed embodiments, individually and in various combinations and partial combinations with one another. The disclosed systems, methods, and apparatus are not limited to any specific aspects or features or combinations thereof, and the disclosed systems, methods, and apparatus do not require the existence of any one or more specific advantages or the resolution of any problem. Any theory of operation is provided for the sake of explanation, but the disclosed systems, methods, and apparatus are not limited to such theories of operation.

[0129] While some operations of the disclosed methods are described in a particular order for convenience of presentation, it should be understood that this method of the specification is reorderable unless a specific ordering is required by the specific terminology used herein. For example, operations described sequentially may, in some cases, be reordered or performed simultaneously. Furthermore, for the sake of simplification, the accompanying drawings may not show the various ways in which the disclosed systems, methods, and apparatus can be used with other systems, methods, and apparatus. In addition, the specification may use terms such as “produce” and “provide” to describe the disclosed methods. These terms are high-level abstractions of the actual operations performed. The actual operations corresponding to these terms vary depending on the specific implementation and are readily recognizable to those skilled in the art.

[0130] In some examples, values, procedures, etc., may be characterized by restrictive terms such as "minimum," "best," "smallest," or "limit." Such descriptions are intended to show that a choice can be made from among many functional alternatives, and it should be understood that such a choice does not need to be better, smaller, or otherwise preferable to other choices.

[0131] This technological innovation can be described in the general context of computer-executable instructions, such as instructions contained in program modules, running on a computing system on a target real or virtual processor. Generally, a program module or component includes routines, programs, libraries, objects, classes, components, data structures, etc., that perform a specific task or implement a specific abstract data type. The functionality of program modules can be combined or separated as desired in various examples. Computer-executable instructions for program modules can be executed within a local or distributed computing system. Generally, a computing system or computing device can be local or distributed and can include any combination of dedicated hardware and / or general-purpose hardware and software that implements the functionality described herein, examples of which include personal computers, handheld devices, tablets, multiprocessor systems, microprocessor-based or programmable consumer electronics, network PCs, minicomputers, mainframe computers, virtual machines, and containerized applications.

[0132] In the various examples described herein, a module (e.g., a component or engine) can be “programmed” and / or “coded” to perform a particular operation or provide a particular function, and computer-executable instructions for the module can be executed to perform such an operation, cause such an operation to be performed, or otherwise provide such a function. The functions described with respect to a software component, module, or engine can be executed as separate software units (e.g., programs, functions, class methods), but do not need to be implemented as separate units. That is, the functions can be incorporated into a larger program or a more general-purpose program, such as one or more lines of code within a larger program or a general-purpose program.

[0133] The algorithms described may be embodied, for example, as software or firmware instructions executed by a digital computer. For example, any of the disclosed methods can be implemented by one or more computers or other computing hardware that are part of a microscopy tool. The computer may be a computer system comprising one or more processors (processing devices) and tangible non-temporary computer-readable media (e.g., one or more optical media disks, volatile memory devices (such as DRAM or SRAM), or non-volatile memory or storage devices (such as hard drives, NVRAM, and solid-state drives (e.g., flash drives)). One or more processors may execute computer-executable instructions stored in one or more of the tangible non-temporary computer-readable media, thereby implementing any of the disclosed technologies. For example, software for implementing any of the disclosed embodiments may be stored as computer-executable instructions on one or more volatile non-temporary computer-readable media, and when executed by one or more processors, the computer-executable instructions cause one or more processors to implement any of the disclosed technologies or a subset of the technologies. [Examples]

[0134] Additional examples of the disclosed technology While the principles of the disclosed technology have been explained and illustrated with reference to the illustrated examples, it will be recognized that the illustrated examples can be modified in configuration and details without deviating from such principles. For example, elements of an example implemented in software can be implemented in hardware, and vice versa. Furthermore, technology from any embodiment can be combined with technology described in any one or more other embodiments. It will be understood that procedures and functions as described with reference to the illustrated embodiments can be implemented in a single hardware or software module, or they can be provided in separate modules. The specific configurations described above are provided for the sake of simplicity, and other configurations can be used.

[0135] Example 1. A method for collecting a dataset, comprising recording multiple data frames by performing a test position measurement at each of multiple sample test positions of a sample for each of the multiple data frames, wherein the test position measurement comprises, for each sample test position, applying an excitation stimulus to the sample test position at a stimulation time, directing a charged particle beam to the sample test position at a probe time separated from the stimulation time by a phase delay, and recording one or more response signals generated through the interaction between the charged particle beam and the sample, wherein the method comprises repeating the performance of a test position measurement with a repeating phase delay in a discontinuous test position measurement for at least one repeating sample test position.

[0136] Example 2. Any embodiment of this specification, in particular the method of Example 1, wherein the dataset has dimensions of 3 + N, where N represents the dimensions of one or more response signals.

[0137] Example 3. The method according to any example of this specification, particularly Example 1 or 2, wherein multiple sample test positions form a two-dimensional grid of positions on the sample.

[0138] Example 4. The method according to any embodiment of this specification, in particular any one of Examples 1 to 3, further comprising scanning a charged particle beam over a sample to direct the charged particle beam to each sample test position, and synchronizing the scanning of the charged particle beam with performing a test position measurement.

[0139] Example 5. Any embodiment of this specification, particularly the method of Example 4, wherein directing a charged particle beam to a sample test position includes directing irradiation pulses to the sample test position, and synchronizing them includes directing the same number of irradiation pulses to each sample test position.

[0140] Example 6. The method according to any embodiment of this specification, in particular any one of Examples 1 to 5, wherein recording multiple data frames involves repeating the process of performing a test position measurement at each sample test position multiple times for each data frame among the multiple data frames, before performing a test position measurement at a subsequent sample test position.

[0141] Example 7. The method according to any example of this specification, in particular any one of Examples 1 to 6, wherein for each data frame of a plurality of data frames, consecutive test position measurements are performed at different sample test positions.

[0142] Example 8. The method according to any embodiment of this specification, in particular any one of Examples 1 to 7, wherein the method comprises repeating the performance of test position measurements, performing the test position measurements multiple times with repeated phase delays at each repeated sample test position to obtain an aggregated dataset corresponding to the repeated sample test positions and repeated phase delays, and further comprising reducing the aggregated dataset for each repeated sample test position and each repeated phase delay.

[0143] Example 9. Reducing the aggregated dataset is a method of any embodiment of this specification, in particular Example 8, which includes merging the aggregated datasets.

[0144] Example 10. The method according to any embodiment of this specification, in particular to any one of Examples 1 to 9, wherein repeating the test position measurement includes recording a plurality of repeated data frames having the same measurement parameters.

[0145] Example 11. Any embodiment of this specification, in particular the method of any one of Examples 1 to 10, wherein recording a plurality of data frames is performed such that for each of the plurality of sample test positions, the test position measurement is performed with the same phase delay for each data frame in the plurality of phase-redundant data frames.

[0146] Example 12. Any embodiment of the Spec, in particular the method of Example 11, further comprising repeating the recording of multiple phase-redundant data frames at each of multiple different phase delays.

[0147] Example 13. A method according to any embodiment of this specification, particularly one of Examples 1 to 12, wherein recording a plurality of data frames is performed such that, for each data frame in the plurality of phase-shift data frames, the test position measurement is performed at each sample test position with a phase delay corresponding to the data frame, which is different from the phase delay corresponding to each other data frame.

[0148] Example 14. Any embodiment of this specification, in particular the method of any one of Examples 1 to 13, wherein the method includes performing a test position measurement with the same phase delay for each of the multiple sample test positions for at least one of the multiple data frames.

[0149] Example 15. Any embodiment of this specification, in particular the method of Example 14, wherein the method comprises performing a test position measurement exactly once at each sample test position for at least one data frame among a plurality of data frames.

[0150] Example 16. Any embodiment of this specification, in particular the method of any one of Examples 1 to 15, wherein the method includes performing a test position measurement with different phase delays at each of two or more sample test positions among a plurality of sample test positions for at least one data frame among a plurality of data frames.

[0151] Example 17. A method according to any embodiment of this specification, particularly any one of Examples 1 to 16, wherein the method includes, for at least one data frame among a plurality of data frames, performing a test position measurement with a first phase delay at each sample test position in a first position subset of a plurality of sample test positions, and performing a test position measurement with a second phase delay different from the first phase delay at each sample test position in a second position subset of a plurality of sample test positions.

[0152] Example 18. Any example of this specification, in particular the method of Example 17, wherein the first position subset and the second position subset are non-overlapping subsets of multiple sample test positions.

[0153] Example 19. The method according to any example of this specification, particularly Example 17 or 18, wherein the first position subset and the second position subset correspond to interlaced portions of multiple sample test positions.

[0154] Example 20. The method according to any example of this specification, in particular any one of Examples 1 to 19, wherein applying an excitation stimulus to a sample test site includes applying an excitation stimulus to a region of the sample encompassing multiple sample test sites.

[0155] Example 21. The method according to any example of this specification, in particular any one of Examples 1 to 20, wherein applying an excitation stimulus to the sample test position includes directing a laser pulse to the sample.

[0156] Example 22. Any example of this specification, particularly the method of Example 21, wherein for each test position measurement, a laser pulse is incident on the sample for a duration of less than 1 picosecond (ps).

[0157] Example 23. The method according to any embodiment of this specification, in particular any one of Examples 1 to 22, wherein directing a charged particle beam to a sample test position includes directing a charged particle beam pulse to a sample test position.

[0158] Example 24. Any example of this specification, in particular the method of Example 23, wherein a charged particle beam pulse is incident on the sample for a duration of less than 1 ps.

[0159] Example 25. Any embodiment of this specification, in particular the method of any one of Examples 1 to 24, wherein directing a charged particle beam to a sample test position includes directing a charged particle beam using one or more scanning coils of a charged particle microscope system.

[0160] Example 26. A method according to any example of this specification, particularly any one of Examples 1 to 25, wherein recording one or more response signals includes one or more of the following: (i) recording a bright-field signal, (ii) recording an annular bright-field signal, (iii) recording an annular dark-field signal, (iv) recording a high-angle annular dark-field signal, (v) recording an energy-dispersive X-ray spectroscopy signal, (vi) recording an electron energy loss spectroscopy signal, (vii) recording a differential phase contrast signal, (viii) recording a focused beam electron diffraction signal, (ix) recording a backscattered electron signal, or (x) recording a secondary electron signal.

[0161] Example 27. The method according to any embodiment of this specification, in particular any one of Examples 1 to 26, wherein recording one or more response signals includes recording using a pixel-type electron detector.

[0162] Example 28. Any embodiment of this specification, in particular the method of any one of Examples 1 to 27, wherein recording one or more response signals includes recording signals corresponding to two or more different analytical methodologies.

[0163] Example 29. Any embodiment of this specification, in particular the method of any one of Examples 1 to 28, wherein recording one or more response signals includes recording using two or more separate detector devices.

[0164] Example 30. The method according to any embodiment of this specification, in particular any one of Examples 1 to 29, further comprising analyzing one or more test data frames following the recording of one or more test data frames from a plurality of data frames, and prior to recording subsequent data frames from the plurality of data frames, to obtain intermediate information about the sample.

[0165] Example 31. Any embodiment of this specification, particularly the method of Example 30, comprising analyzing one or more test dataframes to generate an intermediate representation of a sample based at least partially on one or more test dataframes.

[0166] Example 32. The method according to any embodiment of this specification, particularly the method according to Example 30 or 31, wherein the method is carried out at least in part by a charged particle microscope system, and the method further comprises adjusting one or more measurement parameters of the charged particle microscope system at least in part based on intermediate information following the recording of one or more test data frames and prior to the recording of subsequent data frames.

[0167] Example 33. The method according to any embodiment of this specification, particularly the method of Example 32, wherein the adjustment is carried out at least partially automatically.

[0168] Example 34. The method according to any embodiment of this specification, in particular Example 32 or 33, further comprising displaying and adjusting intermediate information to the user, which is carried out at least partially in response to user input.

[0169] Example 35. A method for collecting a dataset, comprising recording a data frame by performing a test position measurement at each of a plurality of sample test positions of a sample, wherein for each sample test position, the test position measurement includes applying an excitation stimulus to the sample test position at a stimulation time, directing a charged particle beam to the sample test position at a probe time separated from the stimulation time by a phase delay, and recording one or more response signals generated through the interaction between the charged particle beam and the sample, wherein recording a data frame includes performing a test position measurement at each sample test position such that a single phase delay is used at each sample test position, and performing a test position measurement with a different respective phase delay at each of two or more different sample test positions of a plurality of sample test positions.

[0170] Example 36. Any embodiment of this specification, particularly the method of Example 35, further comprising scanning a charged particle beam over a sample to direct the charged particle beam to each sample test position, and synchronizing the scanning of the charged particle beam with performing a test position measurement.

[0171] Example 37. Any embodiment of this specification, in particular the method of Example 36, wherein directing a charged particle beam to a sample test position includes directing irradiation pulses to the sample test position, and synchronizing them includes directing the same number of irradiation pulses to each sample test position.

[0172] Example 38. The method according to any embodiment of this specification, in particular to any one of Examples 35-37, further comprising repeatedly recording a data frame to obtain a plurality of data frames.

[0173] Example 39. The method according to any embodiment of this specification, in particular Example 38, wherein for each data frame of a plurality of data frames, each sample test position is associated with each phase delay according to a phase mapping, and each frame of the plurality of data frames is characterized by the same phase mapping.

[0174] Example 40. The method according to any example of this specification, in particular any one of Examples 35 to 39, wherein consecutive test position measurements are performed at different sample test positions.

[0175] Example 41. The method according to any embodiment of this specification, particularly any one of Examples 35 to 40, further comprising: performing a test position measurement with a first phase delay at each sample test position in a first position subset of multiple sample test positions; and performing a test position measurement with a second phase delay different from the first phase delay at each sample test position in a second position subset of multiple sample test positions. Example 42. The method according to any embodiment of this specification, particularly Example 41, wherein the first position subset and the second position subset are non-overlapping subsets of multiple sample test positions.

[0176] Example 43. The method according to any example of this specification, particularly Example 41 or 42, wherein the first position subset and the second position subset correspond to interlaced portions of multiple sample test positions.

[0177] Example 44. The method according to any example of this specification, in particular any one of Examples 35 to 43, wherein applying an excitation stimulus to a sample test site includes applying the excitation stimulus to a region of the sample encompassing multiple sample test sites.

[0178] Example 45. The method according to any example of this specification, in particular any one of Examples 35 to 44, wherein applying an excitation stimulus to the sample test position includes directing a laser pulse to the sample.

[0179] Example 46. The method according to any of the embodiments herein, particularly the method according to Example 45, wherein for each test position measurement, a laser pulse is incident on the sample for a duration of less than 1 ps.

[0180] Example 47. Directing a charged particle beam to a sample test location is the method according to any of the embodiments herein, in particular any one of Examples 35 to 46, which includes directing a charged particle beam pulse to a sample test location.

[0181] Example 48. Any example of this specification, particularly the method of Example 47, wherein a charged particle beam pulse is incident on a sample for a duration of less than 1 ps.

[0182] Example 49. The method according to any embodiment of this specification, in particular any one of Examples 35 to 48, wherein directing a charged particle beam to a sample inspection position includes directing a charged particle beam using one or more scanning coils of a charged particle microscope system.

[0183] Example 50. A method according to any example of this specification, particularly any one of Examples 35 to 49, wherein recording one or more response signals includes one or more of the following: (i) recording a bright-field signal, (ii) recording an annular bright-field signal, (iii) recording an annular dark-field signal, (iv) recording a high-angle annular dark-field signal, (v) recording an energy-dispersive X-ray spectroscopy signal, (vi) recording an electron energy loss spectroscopy signal, (vii) recording a differential phase contrast signal, (viii) recording a focused beam electron diffraction signal, (ix) recording a backscattered electron signal, or (x) recording a secondary electron signal.

[0184] Example 51. The method according to any embodiment of this specification, particularly any one of Examples 35 to 50, wherein recording one or more response signals includes recording using a pixel-type electron detector.

[0185] Example 52. The method according to any embodiment of this specification, in particular to any one of Examples 35 to 51, wherein recording one or more response signals includes recording signals corresponding to two or more different analytical methodologies.

[0186] Example 53. The method according to any embodiment of this specification, in particular to any one of Examples 35 to 52, wherein recording one or more response signals includes recording using two or more separate detector devices.

[0187] Example 54. The method according to any embodiment of this specification, in particular the method according to any one of Examples 35 to 53, wherein the data frame is a test data frame, and the method further comprises analyzing the test data frame following the recording of the test data frame and prior to recording subsequent data frames to obtain intermediate information about the sample.

[0188] Example 55. The method according to any example herein, particularly the method according to Example 54, wherein analyzing a test data frame is used to generate an intermediate representation of a sample based at least partially on the test data frame.

[0189] Example 56. The method according to any embodiment of this specification, particularly the method according to Example 54 or 55, wherein the method is carried out at least in part by a charged particle microscope system, and the method further comprises adjusting one or more measurement parameters of the charged particle microscope system at least in part based on intermediate information following the recording of a test data frame and prior to the recording of a subsequent data frame.

[0190] Example 57. The method according to any embodiment of this specification, in particular Example 56, wherein the adjustment is carried out at least partially automatically.

[0191] Example 58. The method of any embodiment of this specification, in particular Example 56 or 57, further comprising displaying and adjusting intermediate information to the user, which is carried out at least partially in response to user input.

[0192] Example 59. A charged particle microscope (CPM) system comprising: a charged particle source configured to generate a charged particle beam; an optical assembly configured to direct and focus the irradiation pulse of the charged particle beam to a sample test position on a sample positioned on the sample plane; an excitation source configured to apply an excitation stimulus to the sample test position; a detector subassembly configured to receive one or more response signals generated through the interaction between the irradiation pulse and the sample; and a controller, wherein the controller comprises a processor system and a memory containing instructions, and when an instruction is executed by the processor system, the CPM system causes the CPM system to carry out the method described in any of the embodiments herein, in particular any one of Examples 1 to 58.

[0193] Example 60. (i) The CPM system is equipped with a bright-field electron detector and recording one or more response signals includes recording a bright-field signal using the bright-field electron detector; (ii) The CPM system is equipped with an annular bright-field electron detector and recording one or more response signals includes recording an annular bright-field signal using the annular bright-field electron detector; (iii) The CPM system is equipped with an annular dark-field electron detector and recording one or more response signals includes recording an annular dark-field signal using the annular dark-field electron detector; (iv) The CPM system is equipped with a high-angle annular dark-field electron detector and recording one or more response signals includes recording a high-angle annular dark-field signal using the high-angle annular dark-field electron detector; (v) The CPM system is equipped with an X-ray detector and recording one or more response signals includes recording an energy-dispersive X-ray spectroscopic signal using the X-ray detector; (vi) The CPM system is equipped with an electron energy loss spectroscopic module (vii) a CPM system comprising a module and recording one or more response signals by recording an electron energy loss spectroscopy signal using an electron energy loss spectroscopy module; (viii) a CPM system comprising a pixel electron detector and recording one or more response signals by recording a differential phase contrast signal using a pixel electron detector; (ix) a CPM system comprising a backscatter electron detector and recording one or more response signals by recording a backscatter electron signal using a backscatter electron detector; or (x) a CPM system comprising a secondary electron detector and recording one or more response signals by recording a secondary electron signal with a secondary electron detector, wherein two or more of these are the CPM systems described herein, particularly the CPM system described in Example 59.

[0194] Example 61. A CPM system according to any embodiment of this specification, particularly Example 59 or 60, wherein the excitation source includes a laser source, and the application of the excitation stimulus includes directing the laser pulse to the sample so that the laser pulse is incident on the sample for a duration of less than 1 ps.

[0195] Example 62. A CPM system according to any example of this specification, in particular any one of Examples 59 to 61, wherein the CPM system comprises a scanning electron microscope (SEM) system, the charged particle emitter comprises an electron emitter, and the charged particle beam comprises an electron beam.

[0196] Example 63. A CPM system according to any embodiment of this specification, in particular any one of Examples 59 to 62, wherein the CPM system comprises a scanning transmission electron microscope (STEM) system, the charged particle emitter comprises an electron emitter, and the charged particle beam comprises an electron beam.

[0197] In view of the numerous possible embodiments to which the principles of the invention of this disclosure may be applied, it should be recognized that the illustrated embodiments are merely preferred embodiments of the invention and should not be construed as limiting the scope of this disclosure. Rather, the scope of the invention is defined by the following claims. Accordingly, the inventors claim that all things included within the scope and spirit of these claims are their invention.

Claims

1. A method for collecting datasets, For each of the multiple dataframes, This includes recording the multiple data frames by performing test position measurements at each of the multiple sample test positions of the sample, and performing the test position measurements for each sample test position. During the stimulation time, an excitation stimulus is applied to the sample test site, During the probe time, which is separated from the stimulation time by the amount of phase delay, the charged particle beam is directed to the sample test position, The process includes recording one or more response signals generated through the interaction between the charged particle beam and the sample, The method comprises repeating the process of performing the test position measurement with a repeated phase delay in discontinuous test position measurements for at least one repeatable sample test position.

2. The method according to claim 1, wherein the repetition of performing the test position measurement includes performing the test position measurement multiple times with the repeated phase delay at each repeated sample test position to obtain an aggregated dataset corresponding to the repeated sample test position and the repeated phase delay, and the method further includes integrating the aggregated dataset for each repeated sample test position and each repeated phase delay.

3. The method according to claim 1, wherein the recording of the plurality of data frames includes recording the plurality of phase-redundant data frames such that, for each of the plurality of sample test positions, the test position measurement is performed with the same phase delay for each data frame in the plurality of phase-redundant data frames.

4. The method according to claim 1, wherein the recording of the plurality of data frames includes recording the plurality of phase change data frames such that, for each data frame in the plurality of phase change data frames, the test position measurement is performed at each sample test position with a phase delay corresponding to the data frame, which is different from the phase delay corresponding to each other data frame.

5. With respect to at least one of the plurality of data frames, the method For each of the aforementioned multiple sample test positions, the test position measurement is performed with the same phase delay. The method according to any one of claims 1 to 4, comprising performing the test position measurement accurately once at each sample test position.

6. The method according to any one of claims 1 to 4, wherein recording the one or more response signals includes recording them using two or more separate detector devices.

7. The method according to any one of claims 1 to 4, further comprising analyzing the one or more test data frames following the recording of one or more test data frames from the plurality of data frames, and prior to recording subsequent data frames from the plurality of data frames, to obtain intermediate information about the sample.

8. The method according to claim 7, wherein the method is at least partially carried out by a charged particle microscope system, and the method further comprises adjusting one or more measurement parameters of the charged particle microscope system at least partially based on the intermediate information, following the recording of the one or more test data frames and prior to the recording of the subsequent data frames.

9. The method according to claim 8, wherein the adjustment is performed at least partially automatically.

10. The method of claim 8, further comprising displaying the intermediate information to the user, wherein the adjustment is performed at least partially in response to user input.

11. A method for collecting datasets, This includes recording a data frame by performing a test position measurement at each of the multiple test positions of the sample, and performing the test position measurement for each test position. During the stimulation time, an excitation stimulus is applied to the sample test site, During the probe time, which is separated from the stimulation time by the amount of phase delay, the charged particle beam is directed to the sample test position, The process includes recording one or more response signals generated through the interaction between the charged particle beam and the sample, Recording the aforementioned data frame is The test position measurement is performed at each sample test position so that a single phase delay is used at each sample test position, A method comprising performing the test position measurement at each of two or more different sample test positions among the plurality of sample test positions, with each having a different phase delay.

12. The method according to claim 11, further comprising obtaining a plurality of data frames by repeating the recording of the data frame.

13. The method according to claim 12, wherein for each data frame among the plurality of data frames, each phase delay is associated with each sample test position according to phase mapping, and each frame among the plurality of data frames is characterized by the same phase mapping.

14. The method according to claim 11, wherein consecutive test position measurements are performed at different sample test positions.

15. At each sample test position of the first position subset of the plurality of sample test positions, the test position measurement is performed with a first phase delay, The method according to any one of claims 11 to 14, further comprising performing the test position measurement with a second phase delay different from the first phase delay at each sample test position of the second position subset of the plurality of sample test positions.

16. The method according to claim 15, wherein the first position subset and the second position subset are non-overlapping subsets of the plurality of sample test positions.

17. A charged particle microscope (CPM) system, A charged particle emitter configured to generate a charged particle beam, An optical assembly configured to direct and focus the irradiation pulse of the charged particle beam to a sample test position on the sample positioned within the sample plane, An excitation source configured to apply an excitation stimulus to the aforementioned sample test location, A detector subassembly configured to receive one or more response signals generated through the interaction between the irradiation pulse and the sample, The CPM system comprises a controller, the controller comprising a processor system and a memory containing instructions, and when the instructions are executed by the processor system, the CPM system provides instructions for each of the multiple data frames. By performing test position measurements at each of the multiple sample test positions of the sample, the multiple data frames are recorded, and the performance of the test position measurements is performed as described above. During the stimulation time, the excitation stimulus is applied to the sample test position using the excitation source, During the probe time, which is separated from the stimulation time by the amount of phase delay, the irradiation pulse is directed to the sample test position. The process includes recording one or more response signals generated through the interaction between the charged particle beam and the sample, A CPM system in which the memory includes instructions, and when the instructions are executed by the processor system, the processor system causes the processor system to repeatedly perform the test position measurement with a repeated phase delay in a discontinuous test position measurement for at least one repeatable sample test position.

18. (i) The CPM system includes a bright-field electron detector, and recording the one or more response signals includes recording bright-field signals using the bright-field electron detector. (ii) The CPM system includes an annular bright-field electron detector, and recording the one or more response signals includes recording an annular bright-field signal using the annular bright-field electron detector, (iii) The CPM system includes an annular dark-field electron detector, and recording the one or more response signals includes recording an annular dark-field signal using the annular dark-field electron detector, (iv) The CPM system includes a high-angle annular dark-field electron detector, and recording the one or more response signals includes recording a high-angle annular dark-field signal using the high-angle annular dark-field electron detector. (v) The CPM system includes an X-ray detector, and recording the one or more response signals includes recording an energy-dispersive X-ray spectral signal using the X-ray detector. (vi) The CPM system includes an electron energy loss spectroscopic module, and recording the one or more response signals includes recording an electron energy loss spectroscopic signal using the electron energy loss spectroscopic module. (vii) The CPM system includes a segmented electron detector, and recording the one or more response signals includes recording a differential phase contrast signal using the segmented electron detector. (viiii) The CPM system includes a pixel-type electron detector, and recording the one or more response signals includes recording a converged beam electron diffraction signal using the pixel-type electron detector. (ix) The CPM system includes a backscatter electron detector, and recording the one or more response signals includes recording the backscatter electron signals using the backscatter electron detector, or (x) The CPM system according to claim 17, wherein the CPM system comprises a secondary electron detector, and recording the one or more response signals includes recording a secondary electron signal using the secondary electron detector, and two or more of these.

19. The CPM system according to claim 17 or 18, wherein the excitation source includes a laser source, and the application of the excitation stimulus includes directing the laser pulse to the sample such that the laser pulse is incident on the sample for a duration of less than 1 picosecond (ps).

20. The memory further includes instructions, and when the instructions are executed by the processor system, following the recording of a test data frame from the plurality of data frames and prior to recording subsequent data frames from the plurality of data frames, the CPM system The aforementioned test data frame is analyzed to obtain intermediate information regarding the sample. The CPM system according to claim 17 or 18, which automatically adjusts one or more measurement parameters of the CPM system based at least partially on the intermediate information.

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