Disturbance compensation for charged particle beam devices

Abstract

This relates to disturbance compensation for charged particle beam devices. A charged particle beam device for repair work, for example, is subjected to a disturbance, and the sensor output of one or more sensors is used to compensate for the disturbance during execution of a manipulation mode, for example, to repair a defect on a lithography mask.

Description

[Technical Field]

[0001] Priority This application claims priority to German Patent Application No. 102022124686.8 (filed September 26, 2022), the entire contents of which are incorporated herein by reference.

[0002] The various embodiments of this disclosure generally relate to charged particle beam devices and methods for operating charged particle beam devices. More specifically, the various embodiments relate to compensation for disturbances during the operation of charged particle beam devices. [Background technology]

[0003] For example, charged particle beam devices can be used for microscopic inspection or manipulation of semiconductor structures. Charged particles available for use in charged particle beam devices include electrons, positrons, muons, and ions. Examples of charged particle beam devices include scanning electron microscopes (SEMs), focused ion beam (FIB) devices, and SEMs with multiple beams, sometimes called multi-SEMs.

[0004] For example, Japanese Patent Application No. 2004-079334 discloses electron beam devices such as electron microscopes and electron beam lithography devices equipped with semiconductor electron beam detectors for detecting electron beams. Multiple electron beam sensors are arranged on opposite sides of the mounting substrate, thereby enabling easy replacement of the semiconductor electron beam detector when it is needed.

[0005] A particle microscope can be used to record an image of an object. In this way, for example, the structure of the surface can be analyzed (inspection mode). Alternatively, modifications can be made to the sample, for example, by removing or depositing material (manipulation mode). For example, a charged particle beam device can be used to modify / manipulate a lithography mask. In this case, the charged particle beam device is sometimes called a repair device. An example relating to such a repair device is disclosed in U.S. Patent Application Publication No. 20200912914, which is incorporated herein by reference.

[0006] U.S. Patent Application Publication 2018 / 0277361 discloses a method for depositing material on a sample, comprising directing a charged particle beam onto a substrate to induce deposition of a protective layer from a precursor gas above a region of interest. The protective layer may be a composite mixture of materials having a spot array substantially matching the spot array of the substrate.

[0007] Often, disturbances introduce irregularities into the operation of charged particle beam devices. For example, external disturbances such as fluctuating temperature, pressure, and vibration often affect the beam positioning of the particle beam in the charged particle beam device relative to the sample stage.

[0008] Since measuring the beam offset of a charged particle beam operating in inspection mode or manipulation mode is either impossible or only possible to a limited extent, closed-loop control to compensate for beam offset is not always possible. In the art, forward compensation for individual disturbances is known. This will be described below.

[0009] For example, Japanese Patent Application No. 2003173755 discloses a charged particle beam device including an active magnetic field source configured to counteract disturbances caused by an external magnetic field. However, it has been observed that using the technology disclosed in Japanese Patent Application No. 2003173755 only provides insufficient compensation for placement offset.

[0010] U.S. Patent No. 3,842,272 discloses a scanning charged particle microscope system. The beam scans the sample in a predetermined pattern. Spurious external electric and magnetic fields can be compensated by applying a beam correction signal to the beam scanning means. However, even in this case, using the technique disclosed in U.S. Patent No. 3,842,272 only provides insufficient compensation for the placement offset caused by these spurious external electric and magnetic fields.

[0011] U.S. Patent No. 6,043,490 discloses a charged particle beam apparatus that includes means for individually detecting the x and y components of mechanical vibration and means for correcting the x and y scan signals to eliminate the effects of mechanical vibration. However, employing the technology of U.S. Patent No. 6,043,590 provides only limited ability to compensate for beam alignment offsets of the charged particle beam apparatus due to disturbances.

[0012] U.S. Patent No. 9,601,310 discloses a charged particle microscope that includes a barometric pressure sensor. A control procedure is used to compensate for relative positional errors between the charged particle beam and the sample holder based on the sensor signal from the barometric pressure sensor. Even using the technique disclosed in U.S. Patent No. 9,601,310, only limited accuracy in compensating for positional offsets caused by disturbances can be obtained.

[0013] U.S. Patent No. 4,698,503 discloses a refocusing device used in a transmission electron microscope that is operable to respond to electron beam sensor output signals at discrete irradiation angles. [Overview of the Initiative]

[0014] Therefore, advanced techniques are needed to compensate for beam offset of charged particle beam devices on the sample stage caused by multiple disturbances. Consequently, as the demand for resolution increases, advanced techniques are needed to compensate for beam aberrations such as beam blurring of charged particle beam devices caused by multiple disturbances.

[0015] This need is met by the features of the independent claim. The features of the dependent claim define the embodiments.

[0016] According to the example, the charged particle beam device includes a beam source, a beam deflection unit, and a sample stage.

[0017] In some embodiments, the charged particle beam device implements a charged particle beam repair device, in which case the charged particle beam repair device further includes a precursor gas source. The precursor gas source includes a gas supply source, a supply valve, and a supply nozzle located near the sample stage. In some cases, the charged particle beam repair device may include multiple precursor gas sources to supply different types of precursor gases.

[0018] The beam deflection unit is configured to deflect a beam of charged particles, such as electrons or ions, to position the beam on the sample stage.

[0019] The charged particle beam repair device includes multiple sensors. Each of these sensors is configured to measure multiple disturbances of multiple physical quantities that affect the beam offset of the beam on the sample stage.

[0020] The charged particle beam repair device also includes at least one control unit, such as a microprocessor or processor, configured to execute program code loaded from memory. Built-in electronic devices are also available. Field-programmable gate arrays (FPGAs) can also be used to implement the control unit.

[0021] At least one control unit performs various tasks for beam control and process control.

[0022] The at least one control unit may also process sensor outputs provided by a plurality of sensors to determine one or more compensation signals for suppressing beam offset.

[0023] In some embodiments, the at least one control unit is also configured to supply control signals for performing electron beam-induced manipulation of a sample attached to a sample stage to the beam source, the beam deflection unit and the precursor gas source when a manipulation mode is implemented, for example, to perform sample repair work.

[0024] The at least one control unit is configured to supply one or more compensation signals to at least one of one or more compensation modules disposed at or around the beam source, the beam deflection unit, the sample stage, or the charged particle beam repair device, for example, during the electron beam-induced manipulation or when operating in an imaging mode.

[0025] Such techniques enable disturbance reduction or complete compensation during operation of a charged particle beam device, for example when operating in an imaging mode or a manipulation mode. For example, one or more repair operations can be performed on a semiconductor mask in manipulation mode. Damage to the mask can be avoided by reducing or compensating for disturbances during the manipulation process.

[0026] A method for manipulating a sample attached to a sample stage of a charged particle beam repair device is disclosed. The charged particle beam repair device comprises a beam source, a beam deflection unit, a precursor gas source and the sample stage. The beam deflection unit is configured to deflect a beam of charged particles emitted from the beam source for positioning the beam on the sample stage. The method comprises acquiring sensor outputs from a plurality of sensors of the charged particle beam repair device. The plurality of sensors measure a plurality of disturbances of a plurality of physical quantities each of which affects a beam offset of the beam on the sample stage. The method also comprises determining one or more compensation signals for suppressing the beam offset based on the sensor outputs from the plurality of sensors. The method further comprises supplying control signals for performing electron beam induced manipulation of the sample to the beam source, the beam deflection unit and the precursor gas source. The method still further comprises supplying the one or more compensation signals to at least one of the beam source, the beam deflection unit, the sample stage or one or more compensation modules during the electron beam induced manipulation.

[0027] A computer program, a computer program product or a computer readable storage medium comprises program code. The program code is loadable and executable by at least one processor. When the at least one processor loads and executes the program code, the at least one processor is configured to perform the above method of manipulating a sample.

[0028] In some embodiments, the charged particle beam device includes a beam source, a beam deflection unit, and a sample stage. The beam deflection unit is configured to deflect the beam emanating from the beam source to position the beam on the sample stage. The charged particle beam device includes a plurality of sensors, each configured to measure a plurality of disturbances of a plurality of physical quantities that affect the beam offset of the beam on the sample stage. At least one control unit is configured to determine metadata indicating one or more compensation operations to suppress the beam offset in imaging data acquired by the charged particle beam restoration device operating in imaging mode, based on the sensor outputs of the plurality of sensors. The metadata can be stored in association with the image data.

[0029] A method for post-processing image data acquired by a charged particle beam device is disclosed. The charged particle beam device includes a beam source, a beam deflection unit, and a sample stage. The beam deflection unit is configured to deflect the beam emanating from the beam source to position the beam on the sample stage. The method includes acquiring the sensor outputs of multiple sensors of the charged particle beam device. The multiple sensors measure multiple disturbances of multiple physical quantities, each affecting the beam offset of the beam on the sample stage. The method also includes determining metadata based on the sensor outputs of the multiple sensors. The metadata indicates one or more compensation operations to suppress the beam offset in the image data. The image data is acquired by the charged particle beam device when it is operating in imaging mode. The method also includes post-processing the image data according to one or more compensation operations based on the metadata.

[0030] A computer program, computer program product, or computer-readable storage medium includes program code. The program code is loadable and executable by at least one processor. The at least one processor is configured to load and execute the program code and then perform the post-processing of image data in the manner described above.

[0031] Such technologies enable the reduction or complete compensation of disturbances in post-processing of imaging data acquired by charged particle beam devices, for example, when operating in imaging mode.

[0032] It should be understood that the features described above and those described below may be used in other combinations or separately without departing from the scope of the present invention, as well as in each of the combinations shown. [Brief explanation of the drawing]

[0033] [Figure 1] This diagram schematically shows the arrangement offset of charged particle beams in various embodiments. [Figure 2] This figure schematically illustrates the compensation for the placement offset in Figure 1 using various embodiments. [Figure 3] This figure schematically illustrates the compensation for the placement offset in Figure 1 using various embodiments. [Figure 4] This figure schematically illustrates the focal offset of a charged particle beam and its corresponding compensation in various embodiments. [Figure 5] This diagram schematically illustrates focus offset and its corresponding compensation in various embodiments. [Figure 6] This diagram schematically illustrates charged particle beam devices according to various embodiments. [Figure 7] This flowchart shows the methods as demonstrated by various embodiments. [Figure 8] This flowchart shows the methods as demonstrated by various embodiments. [Figure 9]This figure schematically shows the time-series data of sensor outputs and the characteristic fingerprints of disturbances in each physical quantity for various implementations. [Figure 10] This flowchart shows the methods as demonstrated by various embodiments. [Figure 11] This figure schematically illustrates various embodiments of a charged particle beam device using a repair device. [Figure 12] This figure schematically shows the relative sensor placement to the repair device in Figure 11, according to various embodiments. [Figure 13] This figure schematically shows the sensor arrangement in the repair device shown in Figure 11, according to various embodiments. [Figure 14] This diagram schematically illustrates defects in lithography masks based on various embodiments. [Figure 15] This diagram schematically illustrates repaired defects in lithography masks using various embodiments. [Figure 16] This diagram schematically illustrates charged particle beam devices according to various embodiments. [Modes for carrying out the invention]

[0034] Some embodiments of this disclosure generally provide a plurality of circuits or other electronic devices. All references to these circuits and other electrical devices and the functions provided by each are not intended to be limited to those shown and described herein. Various circuits or other electrical devices disclosed may be given certain labels, but such labels are not intended to limit the range of operation of the circuits and other electrical devices. Such circuits and other electrical devices may be combined with and / or separated from each other in any way based on a desired particular type of electrical embodiment. Any circuit or electrical device disclosed herein is recognized to include any number of microcontrollers, graphics processor units (GPUs), integrated circuits, memory devices (e.g., flash, random access memory (RAM), read-only memory (ROM), electrically programmable read-only memory (EPROM), electrically erasable programmable read-only memory (EEPROM), or other suitable variations thereof) and software that work together to perform the operations disclosed herein. Furthermore, one or more of the electrical devices may be configured to execute program code implemented on a non-transient computer-readable medium programmed to perform any number of functions as disclosed.

[0035] Embodiments of the present invention will be described in detail below with reference to the accompanying drawings. It should be understood that the following description of embodiments is not to be construed as restrictive. The scope of the present invention is not intended to be limited by the embodiments described below or in the drawings, which should be construed as merely illustrative.

[0036] The drawings should be considered schematic representations, and the elements depicted in the drawings are not necessarily shown to a uniform scale. Rather, the various elements are represented in a way that their function and general purpose will be apparent to those skilled in the art. Any connection or coupling between functional blocks, devices, components, or other physical or functional units shown in the drawings or described herein may be carried out by indirect connection or coupling. Coupling between components may also be established via wireless connections. Functional blocks can be implemented in hardware, firmware, software, or a combination thereof.

[0037] The following discloses techniques related to particle beam devices. Specifically, techniques related to charged particle beam devices are disclosed. The charged particles usable by such devices are electrons and / or ions. In other embodiments, uncharged particles, such as photons, may be used. However, the techniques described below are explained in the context of charged particle beam devices for illustrative purposes.

[0038] Examples of charged particle beam devices include SEMs, aberration-corrected SEMs (typically having relatively large detection apertures so as to have a small depth of field range), FIB devices, multi-SEMs, cross-beam devices including SEM and FIB optics, and SEMs or FIBs with a precursor gas source for repair / circuit repair work in manipulation mode (also called repair devices, as described in detail below in relation to Figure 11).

[0039] Repair work relates to modifying structures on semiconductor masks used for lithography. Repair work is performed using electron beam-induced manipulation of a sample based on the interaction of one or more precursor gases with an electron beam. Alternatively or in addition to this, ions can be used for repair or modification work. In some embodiments, repair work is employed to make changes to semiconductor devices, such as electrical circuits on a wafer. In detail, charged particles, such as electrons, or ions such as helium or neon are used to modify such structures. For example, a charged particle beam interacts with one or more precursor gases selectively supplied toward the sample stage. Then, one or more components of the one or more precursor gases are deposited on the structure. In embodiments, it is also possible to remove material using, for example, a focused ion beam. Repair work is generally associated with the manipulation mode of a charged particle beam device on which the sample / sample is manipulated. Repair work, in principle, involves the execution of control of the beam source and beam deflection unit and precursor gas supply source, using respective control signals to perform electron beam-induced manipulation of the sample. Examples of manipulation include electron-beam-induced deposition (EBID) and electron-beam-induced etching (EBIE). Exemplary restoration procedures will be described in more detail later in relation to Figures 14 and 15.

[0040] The various techniques disclosed herein are based on the observation that the demands for precision in the operation of charged particle beam devices are increasing with the sustained miniaturization of typical dimensions of structures being inspected or modified (typically, structures characterized by limit dimensions indicating the minimum structural size that needs to be handled). For example, typical limit dimensions may be less than 7 nanometers, or even less than 5 nanometers.

[0041] The following discloses techniques for facilitating the operation of charged particle beam devices in high-precision inspection and / or manipulation modes, enabling the handling of structures with minute limit dimensions, such as less than 7 nanometers or even less than 5 nanometers.

[0042] This is achieved by supplying one or more compensation signals to compensate for the beam offset. Details regarding such beam offset and associated compensation are disclosed in relation to the following figures.

[0043] Figure 1 schematically shows a charged particle beam 91, such as an electron beam or an ion beam of helium ions, in a charged particle beam device. The charged particle beam 91 is focused to a specific position 85 on the sample stage 113 of the charged particle beam device by the optical system of the beam deflection unit 112. However, one or more disturbances can cause a beam offset, in this case a positional offset 81 that shifts the charged particle beam 91 toward another position 86 on the sample stage 113. This is a shift in the x-direction. Similarly, a shift in the y-axis direction can also occur. In addition to such a positional offset 81, disturbances can also cause other aberrations that lead to a decrease in accuracy.

[0044] In principle, the accuracy of a charged particle beam device depends on both the resolution of the charged particle beam and the arrangement of the charged particle beam on the sample stage. Typical resolution is defined by a beam diameter typically in the range of 3 to 5 nanometers or even smaller (less than 1 nm in the case of aberration-correcting devices). On the other hand, the arrangement of the charged particle beam on the sample stage is typically influenced by multiple disturbances of multiple physical quantities that affect the beam offset, including the arrangement offset described above in relation to Figure 1. A further type of beam offset is the focal offset, which will be discussed later in relation to Figures 4 and 5.

[0045] Because the specification requirements imposed on the precision of the placement of charged particle beams on the sample stage are often even higher than those imposed on beam diameter / resolution, such placement offsets that degrade beam placement precision are particularly critical to the operation of charged particle beam devices. One reason for this is that, for example in relation to manipulation mode, certain structures need to be generated or modified with an accuracy of less than 3 nanometers, optionally less than 2 nanometers, or even less than 1 nanometer. Furthermore, while placement offsets when operating in inspection mode can degrade the overall image quality of the resulting image, placement offsets caused by disturbances during manipulation can result in damage to expensive semiconductor structures or even lithography masks.

[0046] Therefore, a technique is disclosed for facilitating the compensation of positional offset and focal offset by supplying one or more compensation signals when a charged particle beam device is operating in manipulation mode.

[0047] According to various embodiments, a charged particle beam device includes multiple sensors for measuring multiple disturbances of multiple physical quantities. All of these multiple physical quantities affect the beam offset of the beam on the sample stage. The charged particle beam device also includes a control unit configured to determine one or more compensation signals to suppress the beam offset based on the sensor outputs of the multiple sensors. The control unit is configured to supply one or more compensation signals to at least one of the beam source of the charged particle beam device, the beam deflection unit of the charged particle beam device, the sample stage, or one or more compensation modules.

[0048] In principle, the beam offset may include at least one of the following: a beam alignment offset (along the X or Y direction in Figure 1, i.e., along the plane of the sample stage 113), or a beam focus offset (along the Z direction in Figure 1, perpendicular to the plane of the sample stage 113).

[0049] By considering disturbances arising from multiple physical quantities, comprehensive compensation for beam offset can be obtained. Specifically, more accurate compensation can be obtained compared to scenarios known from conventional techniques where only individual physical quantities such as temperature, pressure, vibration, or acoustic vibration (i.e., sound waves) are considered in isolation. To more accurately compensate for beam offset, cross-correlations between different pairs of physical quantities can be taken into account. For example, nonlinear effects resulting from cross-correlations can be considered.

[0050] In principle, according to the examples, various physical quantities are considered for compensation. Multiple physical quantities are selected from a group that includes acoustic vibrations, vibrations, pressure, humidity, laminar flow, turbulent flow, differential quantities, temperature, rate of change (i.e., defining the rate of change over time), differential quantities, vector quantities (e.g., electric field, magnetic field), or scalar quantities (e.g., temperature, pressure).

[0051] A differential quantity represents the spatial gradient of each quantity, such as a temperature gradient or a pressure gradient. Often, such differential quantities can impart stress or strain to a material, thereby creating disturbances. Further examples include laminar flow and turbulent flow.

[0052] Acoustic vibrations, in some embodiments, include external acoustic vibrations arising, for example, from objects moving around the charged particle beam device. In the prior art, passive attenuation systems are known that attempt to isolate a charged particle beam device from its surroundings. However, such passive attenuations typically cannot absorb all acoustic vibrations, and therefore, the active compensation described herein may be desirable. Acoustic vibrations may have residual components from moving parts within the charged particle beam device. Such internal components can be excited by external acoustic vibrations via mechanical contact, for example, through the floor or support wires, or via sound.

[0053] Pressure fluctuates as a function of time in some embodiments. Pressure fluctuations can occur on relatively long time scales, compared, for example, to acoustic vibrations. Passive compensation by pressure stabilization systems is known. However, such passive compensation has some limitations in accuracy. Pressure fluctuations can occur with respect to the coolant or ambient air. Ambient pressure fluctuations cause variations in the force applied to the vacuum housing of charged particle beam devices, thereby causing changes in the hardware mechanism.

[0054] Temperature fluctuations are compensated to some extent by passive temperature control, for example, using a stabilized temperature chamber or an external air conditioning system, according to some embodiments. Even small temperature fluctuation disturbances can be compensated more accurately using active control according to the techniques disclosed herein. For example, the temperature fluctuation of a coolant is measured in various embodiments using appropriately placed temperature sensors. In further embodiments, the temperature of the coolant is measured. In further embodiments, temperature fluctuations of an electronically controlled device or measuring device are measured and compensated. According to embodiments, the temperature difference / gradient between two or more components of a charged particle beam device is measured. For example, the temperature gradient between different measurement points in a fluid flow, such as a coolant, is measured and the respective disturbances are compensated.

[0055] Another physical quantity that can introduce disturbances is the electric field. Conventional systems often employ shielding for each. However, while such shielding may be somewhat effective against external electric fields, internally generated electric fields resulting from, for example, electric current or induced current or capacitance charging cannot be easily shielded using external shielding. Undesirable charging of particles inside the column by a charged particle beam can occur. On the other hand, using the techniques described herein, to measure the electric field and then compensate for such an electric field, in some embodiments, sensors are used, for example, near the optics inside the vacuum chamber of the charged particle beam device. Similar observations apply to magnetic fields.

[0056] As can be seen from the above, some disturbances, such as magnetic or electric fields, directly affect the charged particle beam by deflecting charged particles propagating along the beam. For example, electric or magnetic fields exert a force on electrons or charged ions, deflecting these particles. These are direct disturbances. Disturbances can also indirectly affect the charged particle beam by affecting one or more components of the charged particle beam device. For example, acoustic vibrations cause a positional offset of the optical system of the beam deflection unit of the charged particle beam device, and this positional offset then causes a beam offset of the beam. Electric or magnetic fields change the analog supply current or voltage of the optical system of the beam source or beam deflection unit of the charged particle beam device, which then affects the positional offset. These are indirect disturbances. According to the techniques disclosed herein, it is possible to compensate for both direct and indirect disturbances.

[0057] For example, a positional offset, as shown in Figure 1, or more generally, a beam offset, can occur in the imaging mode of a scanning electron microscope. For instance, the movement of magnetic materials such as iron, cobalt, nickel, and steel can alter the magnetic field at the location of a charged particle beam. This can be caused by movement around a charged particle beam device, such as elevators, cranes, doors, lifting trucks, moving people, mobile phones, keys, etc.

[0058] Similar considerations apply to focused ion beam devices. Using a focused ion beam, it is possible to remove material from a sample in manipulation mode. If disturbances affecting the ion beam occur, material will be removed in unintended areas of the sample. Therefore, the ion beam is stabilized on the sample and on the sample stage, respectively, using the techniques disclosed herein. This helps avoid damage to the sample and enables higher accuracy, for example, in the preparation of thin plates for transmission electron microscopy or in 3D tomography sample inspection.

[0059] Similarly, in the mask repair process in manipulation operations, structures on the lithography mask are repaired by depositing material using an electron or ion beam-induced process and / or by locally removing material from the lithography mask. By using the techniques disclosed herein, any beam offset of the electron or ion beam relative to the lithography mask and sample stage is reduced, respectively, to achieve higher precision in the manipulation operation.

[0060] In principle, various options are available to suppress beam offset according to the disclosed embodiments. According to the embodiments, different options are employed to suppress beam offset for different root causes of disturbances. For example, different options are employed to suppress beam offset for direct and indirect disturbances, respectively, as described above. For example, a compensation signal is applied to the optics of the beam deflection unit to steer the beam in the opposite direction compared to the positional offset. For example, a compensation signal is applied to the focusing optics of the beam deflection unit to change the focal length in order to suppress the focal offset caused by each disturbance. In some embodiments, the sample stage is controlled to reposition in order to suppress the beam offset, either instead or in addition to the above. In further embodiments, dedicated compensation is used, such as an external coil for applying a magnetic field or an electric field plate for applying an electric field. For example, a Helmholtz coil pair, one pair of coils in each spatial direction, is used to obtain compensation for a DC magnetic field or a slowly changing magnetic field. Such a coil pair is located outside the housing of the charged particle beam device. According to further embodiments, active cooling or heating is used. For example, a heating or cooling element that is in thermal contact with a coolant is provided, enabling active temperature control. In some embodiments, active damping is controlled to suppress vibration. In some embodiments, pressure is actively controlled. Hereinafter, a device or unit that indirectly suppresses beam offset, that is, does not directly apply a force to the charged particle beam by applying a magnetic or electric field, or shifts the sample stage relative to the charged particle beam, is referred to as a compensation module. Such compensation modules are controlled by their respective compensation signals.

[0061] The following primarily describes techniques related to applying compensation signals to the beam deflection unit and / or sample stage. Several exemplary options for suppressing beam offset by such means are described.

[0062] Figure 2 shows an embodiment of compensation for the alignment offset 81 in Figure 1. As shown in Figure 2, an additional beam shift 82 is realized to suppress the alignment offset 81 by supplying a control signal to the beam deflection unit 112. For example, an additional voltage is applied to each electron lens.

[0063] Figure 3 schematically illustrates the suppression of the placement offset 81 in Figure 1. In the scenario of Figure 3, a compensation signal is applied to the control motor of the sample stage 113 to cause a stage shift 83 that suppresses the placement offset 81.

[0064] The techniques shown in Figure 3 may be particularly useful for the closed-loop controlled motorized stage 113. For example, interference stages that can achieve positioning accuracy in the nanometer range are known.

[0065] The above describes scenarios of placement offsets affected by multiple disturbances. Instead of, or in addition to, the disturbances can affect the focal offset of the charged particle beam. This is shown in Figure 4.

[0066] Figure 4 shows an unaffected beam 91 in the absence of any disturbances. It also shows two disturbed beams 93 and 94, each exhibiting a focal offset 71 and 72. The focal offsets 71 and 72 can be suppressed by adding additional defocus to the beam. The beam deflection unit 112 can be controlled accordingly. A defocus 75 for suppressing the focal offset 71 is shown, and a defocus 76 for suppressing the focal offset 72 is also shown. In another scenario, vertical stage shifts 77 and 78 can also be added, as shown in Figure 5.

[0067] According to various embodiments, focus offset compensation is applied to aberration-corrected SEMs. Typically, aberration-corrected SEMs have a relatively large numerical aperture and therefore a shallow depth of field. Such aberration-corrected SEMs can be employed in manipulation work, where the thickness of the structure being manipulated is within or less than the depth of field range. In such scenarios, focus offset compensation is particularly important to obtain good results in the manipulation work.

[0068] Various techniques are based on the understanding that disturbances can occur on different time scales. On the other hand, there can be slowly changing disturbances, such as those caused by DC magnetic fields, temperature, or pressure changes. Typically, such slowly changing disturbances can be compensated using the techniques disclosed herein, for example, by applying one or more compensation signals to suppress beam offset. Here, the use of compensation by applying an additional voltage to the beam optics (see Figure 2 or Figure 4) typically results in a shorter response time compared to giving stage shift-based compensation (see Figures 3 and 5). This is because the movement of the stage typically requires a longer time due to the limited movement speed of the motor. The operation of the charged particle beam device, for example, the imaging mode or the manipulation mode, does not need to be stopped for such compensation; i.e., compensation can be applied during ongoing operation.

[0069] On the other hand, some disturbances can change on a fast timescale, for example, within a few seconds or less than a second. One example relates to physical quantities such as acoustic or seismic vibrations caused by vibrations in a building foundation. To compensate for such fast disturbances as well, a technique is disclosed below that enables the determination of a predictive component of beam offset. In addition to or instead of the above, in further embodiments, information about such disturbances is stored, and such information is determined based on sensor outputs, for example, together with imaging data acquired in imaging mode. In other words, according to the embodiment, metadata indicating one or more compensation operations to suppress beam offset in image data acquired by a charged particle beam device operating in imaging mode is determined based on the sensor outputs of multiple sensors, and the metadata is then stored associated with the image data. Next, the acquired image data is digitally post-processed after acquisition in order to compensate for such disturbances based on the metadata.

[0070] In some embodiments, disturbances are detected that cause interruptions in the operation of the charged particle beam device. For example, the charged particle beam may be blanked. The imaging mode or manipulation mode is interrupted until the disturbance is resolved. Such scenarios are particularly useful in manipulation mode to avoid damage to the sample being manipulated.

[0071] Figure 6 shows the charged particle beam device 100 according to various embodiments. For example, the charged particle beam device 100 can be a charged particle beam repair device. The charged particle beam device 100 includes a vacuum chamber 110. Inside the vacuum chamber 110 are a beam source 111, a beam deflection unit 112, and a sample stage 113. An integrated control unit 119 controls the beam source 111, the beam deflection unit 112, and the sample stage 113. The control unit 119 can also control further components of the charged particle beam device 100, such as a control valve for a precursor gas source (not shown in Figure 6).

[0072] Two sensors 121 and 122 are also shown, each for measuring disturbances of physical quantities that affect the beam offset of the charged particle beam 90 on the sample stage 113.

[0073] Although the scenario in Figure 6 shows two sensors 121 and 122, in principle, only a single sensor or more than two sensors are used.

[0074] In some embodiments, at least one of the multiple sensors is located inside the vacuum chamber 110. Alternatively, or in addition to this, at least one sensor is located outside the vacuum chamber 110.

[0075] For example, sensors that measure the same physical quantity, such as temperature, are placed at multiple locations. This allows for the measurement of differential physical quantities, such as temperature differences or pressure differences.

[0076] By placing the sensor outside the vacuum chamber, it is possible to measure physical quantities that change slowly as a function of position, such as an external electric field or an external magnetic field. At the same time, it is possible to avoid affecting the particle beam by operating the sensor. In some embodiments, however, sensors for physical quantities that exhibit strong position dependence, for example, are placed closer to the beampath of beam 90.

[0077] A control unit 130 is also shown. In some embodiments, the control unit 130 is performed by a computer. The control unit 130 communicates with the built-in control unit 119 and sensors 121 and 122. Figure 6 shows a scenario in which the control unit 130 communicates directly with sensors 121 and 122, but in other embodiments, such communication is via the built-in control unit 119.

[0078] In either case, the control unit 130 obtains sensor signals 161 and 162 (i.e., sensor outputs) from sensors 121 and 122. Based on this, the control unit 130 supplies one or more compensation signals 165 to one or more components of the charged particle beam device 100 to suppress the alignment offset.

[0079] The control unit 130 includes a processor 132 coupled to a memory 133. The processor 132 also communicates via a communication interface 131. The processor loads program code from the memory 133 and executes the program code. When executing the program code, the processor 132 performs the techniques disclosed herein with respect to compensating for multiple disturbances of multiple physical quantities, each affecting the beam offset.

[0080] The control unit 130 also includes a human-machine interface (HMI) 134, such as a display, web interface, mouse, or keyboard. User input is received or information is output via the HMI 134. For example, site-specific disturbance events are obtained from the user via the HMI 134. In some embodiments, warnings are output to the user via the HMI 134.

[0081] The following describes a scenario relating to the logic related to beam offset compensation present in the control unit 130, although in other embodiments, at least a portion of that logic resides in the internal control unit 119.

[0082] Figure 7 is a flowchart of the method according to various embodiments. Figure 7 shows multiple phases of operation of a charged particle beam device, such as the charged particle beam device 100 in Figure 6. The method in Figure 7 can be performed by the control unit 130 and / or the built-in control unit 119.

[0083] Box 6005 corresponds to the calibration phase. In the calibration phase, one or more transfer functions are set between the sensor outputs of multiple sensors that measure disturbances of multiple physical quantities and the compensation signals.

[0084] Therefore, such a transfer function links the values ​​of several physical quantities (represented by sensor signals 161 and 162) to beam offset compensation (represented by compensation signal 165).

[0085] Next, box 6010 corresponds to the operation phase. In the operation phase, the charged particle beam device operates in imaging mode or manipulation mode. For example, as part of imaging mode, the control unit of the charged particle beam device can supply control signals to the beam source and beam deflection unit of the charged particle beam device to perform imaging of a sample attached to the sample stage of the charged particle beam device. As part of manipulation mode, the control unit of the charged particle beam device supplies control signals to the beam source, beam deflection unit and precursor gas source (including, for example, a gas bath or tank and its respective nozzle located near the sample stage; details are described in relation to Figure 11A) to perform electron beam-induced manipulation of a sample attached to the sample stage. Here, the precursor gas supply by the precursor gas source interacts with electrons in the electron beam. Material can be deposited or locally etched.

[0086] During the operation phase, compensation for multiple disturbances of multiple physical quantities is employed, each of which affects the beam offset of the charged particle beam device relative to the sample stage. For example, the control unit employs a transfer function obtained from box 6005 to determine one or more compensation signals to contact the beam offset based on the sensor outputs of multiple sensors, and then to supply one or more compensation signals to one or more components of the charged particle beam device.

[0087] Figure 7 also shows an optional post-processing phase associated with box 6015. Here, metadata obtained based on the sensor outputs of multiple sensors is used to apply one or more compensation operations to suppress beam offset by post-processing each image data. In some embodiments, such compensation operations include applying imaging shifts, for example, shifting the pixels of the image in the image data by a certain image offset. Further embodiments may use rotational or skew operations. In some embodiments, composite image artifacts are compensated for. Examples of image artifacts include artificially repeated contrasts. To compensate for this, compensation operations can be performed, for example, using a neural network to obtain configuration information in the form of metadata.

[0088] As shown by the dashed line in Figure 7, it is possible to periodically re-run the calibration mode of box 6005. This captures certain disturbance events that are site-specific, i.e., dependent on the specific deployment site of the charged particle beam device. This will be discussed in more detail later.

[0089] Next, details regarding the calibration phase of box 6005 are disclosed in relation to Figure 8.

[0090] Figure 8 is a flowchart of the method according to various embodiments. Figure 8 shows details regarding the calibration phase of box 6005.

[0091] First, one or more disturbances are applied in box 6105. This is done by changing one or more physical quantities. Some embodiments include applying a specific disturbance electric or magnetic field (e.g., using a Helmholtz coil mechanism around a charged particle beam device), changing the ambient temperature (e.g., in a temperature-stabilized environment), changing the ambient pressure, etc., where one or more disturbances are applied actively and the magnitude of each disturbance is known.

[0092] As can be seen from the above, these "adjusted" disturbance events are triggered in this way for the purpose of calibration.

[0093] In principle, such active application of a particular disturbance is optional. In other scenarios, spontaneous disturbances, such as site-specific disturbances, are measured in box 6110. In other words, in some scenarios, disturbance events are actively triggered in box 6105, while in other scenarios, environmental disturbance events are monitored and characterized in box 6110.

[0094] Next, the beam offset can be measured in box 6115.

[0095] This beam offset may result from each controlled disturbance actively applied in box 6105, or the beam offset may result from a naturally occurring disturbance, such as an environmental disturbance event. For example, beam placement offset and / or focal offset can be measured. This can be done, for example, using a test pattern sample and each inspection operation. For example, an image of the test pattern acquired by a charged particle device operating in imaging mode in the presence of disturbances is compared to ground truth knowledge about the test pattern. Conclusions about the beam offset can be drawn from the discrepancy between the appearance of the image of the test pattern and the ground truth about the test pattern. For example, the image shift between the true location of certain features of the test pattern and the location where those features are shown in the image can be determined. For example, image blur can be quantified to determine the focal offset.

[0096] Next, in box 6120, the transfer function between the disturbance and the beam offset is determined. This transfer function is then stored for later use during the compensation mode (see box 6010 in Figure 7).

[0097] Next, we will describe various examples of how to determine the transfer function in box 6120.

[0098] In one embodiment, one or more compensation signals are determined using a lookup table that associates the sensor output with one or more compensation signals. In other words, multiple intensities of disturbances, such as multiple values ​​of each physical quantity, the associated beam offset, and the necessary compensation signals to compensate for them are determined. Each pair of values ​​is then stored in the lookup table. Linear interpolation is optionally used during the operation phase to improve accuracy.

[0099] Lookup tables can be device-specific, meaning different charged particle beam devices may have different lookup tables. Site-specific disturbances can be used to populate such device-specific lookup tables. Lookup tables can also be stored in the cloud and therefore retrieved via the internet. This allows for centralized maintenance and management of disturbance compensation for multiple charged particle beam devices.

[0100] Table 1 below shows an example lookup table. [Table 1]

[0101] Such lookup tables have the advantage of not requiring the modeling of the dependency between the sensor output and the compensation signal using a given function. Nonlinear dependencies are captured directly. On the other hand, such lookup tables can be quite large. This can introduce latency in finding a suitable compensation signal, which can be problematic, especially in the case of rapidly changing disturbances.

[0102] In another embodiment, one or more compensation signals are determined using (pre-parameterized) functional dependencies. Such functional dependencies are shown for the linear case.

[0103] For example, in the case of a scalar physical quantity, such as temperature, such a linear function dependency can be defined as follows:

number

[0104]

number

[0105] For example, in the case of a vector physical quantity, such as an electric field, such a linear function dependency is defined as follows:

number

[0106] In some scenarios, cross-dependencies between multiple disturbances associated with different physical quantities are considered.

[0107] For example, one example is the cross-dependent relationship between temperature and pressure, as described below.

number

[0108] While the linear function dependency was disclosed above, it is equally possible to include nonlinear terms, such as quadratic or cubic terms.

[0109] In addition to the function dependencies exemplified above, in another embodiment, one or more compensation signals are determined using a model. For example, positioning offset and focus offset compensations are determined using a neural network or other machine learning algorithm, or generally a pre-trained algorithm. The trained neural network takes as input a vector containing the sensor outputs of multiple sensors, such as temperature, pressure, multiple components of the electric field, multiple components of the magnetic field, etc. The neural network then outputs one or more compensation signals, or beam offsets from which one or more compensation signals are determined. Such a neural network is trained using the ground truth label acquired during calibration mode, i.e., the measured beam offset in box 6115, in combination with the input vector obtained in box 6105 or box 6110.

[0110] This is an example of a data-driven model. In other embodiments, an analytical model may be employed. For example, it has been shown that a change in pressure causes torsion of the beam optical column. This results in a focal shift on a circle tilted with respect to the surface of the sample stage, i.e., the shift has x, y, and z components. A focal offset in the +z or -z direction may occur. According to one embodiment, an analytical model is determined, which determines the torque applied to the optical column based on the pressure gradient. Such an analytical model has the advantage of reducing the lead time in parameterization compared to, for example, the time-consuming calibration of the transfer function. Such a model can be extended in some embodiments to also address placement offsets based on other disturbances such as magnetic fields.

[0111] The above describes a scenario for immediate disturbance compensation. Such techniques are generally effective for slowly changing disturbances, such as those in the kHz range or below. For rapidly changing disturbances, even higher accuracy can be achieved by considering the time-resolved characteristics of the disturbance. This will be discussed in detail below.

[0112] According to various embodiments, a predicted component of the beam offset is determined based on the sensor outputs of multiple sensors, and one or more compensation signals are determined based on this predicted component. In other words, disturbances are predicted to some extent in advance.

[0113] Such technologies are based on the observation that certain disturbance events are recurring. Specifically, site-specific disturbance events may occur repeatedly over a period of time. For example, the movement of an office chair between two desks in a test laboratory or a charged particle beam device deployment site may generate a stray magnetic field. For example, vibrations may be generated by trains arriving and departing at a nearby station or delivery trucks arriving and departing at a shipping center. In another example, the operation of equipment in a wafer manufacturing plant, such as opening and closing load locks, depressurizing a vacuum chamber, or temperature changes as a function of daylight / sunset, may generate a stray magnetic field. These are just a few examples of typical site-specific recurring disturbance events.

[0114] To make such predictions, in some embodiments, the sensor output of at least one of several sensors includes its respective time-series data. In other words, sensor readings over a specific observation period (along with their respective timestamps) are considered. Then, the prediction component is determined based on an analysis of this time-series data.

[0115] There are various options for performing this type of analysis on time series data. One option involves detecting fingerprints of one or more predetermined disturbance events in the time series data. These fingerprints include characteristic time dependencies of sensor outputs from at least one sensor. The fingerprints relate to characteristic time-domain patterns, which are illustrated in relation to Figure 9.

[0116] Figure 9 shows, as an example, a disturbance in the x-component of the electric field that affects the beam offset of a charged particle beam over a certain period of time. The time-series data 310 of the x-component of the electric field is acquired from each electric field sensor.

[0117] As an example, it is shown that a disturbance event 311 occurs due to the arrival of a bus at a bus stop near the deployment site of a charged particle beam device. The duration of each disturbance 313 is also shown. For example, the duration of the disturbance 313 may be within the range of a few seconds or a few minutes.

[0118] The disturbance event 311 has a characteristic fingerprint 312 (here, a large rise followed by a small fall) detected in the time-series data of the electric field sensor. After this fingerprint 312 is detected, it is possible to predict the future behavior of the disturbance, that is, to determine the predicted component of the beam offset (assuming the repetitive nature of each disturbance). The behavior of the disturbance during the remaining disturbance period 313 can then be predicted.

[0119] During the calibration phase operation of box 6005 (see Figure 7), in some embodiments, fingerprints of multiple disturbance events are placed in the repository. Several options are possible for finding such fingerprints. One option is to identify fingerprint repetitions. For example, during calibration mode, the sensor output of at least one sensor is monitored over a long period, e.g., several hours, several days, or even several weeks, and then fingerprint repetitions are found. A further option is to acquire user input data indicating one of one or more disturbance events. For example, referring to Figure 9, the user labels / annotates time-series data to identify disturbance period 313. The user may do this by domain knowledge; for example, in the embodiments described herein, the user may be aware of bus arrivals at bus stops. Other options include training a predictive model based on time-series data measured during calibration mode to find fingerprints. In this case, a predictive model for determining the predicted component of the beam offset, such as a recurrent neural network, e.g., a Long Short-Term Memory (LSTM) neural network, is possible. This allows for response to disturbance events with high-bandwidth signal components. In other words, it can compensate for disturbance events with fast time dynamics, such as in the sub-millisecond or even microsecond range. This is because, after a fingerprint is detected, the compensation signal can be deployed proactively.

[0120] Figure 10 is a flowchart of the example method. Figure 10 schematically shows the operation of box 6010 in Figure 7 during its operation phase.

[0121] In box 6205, multiple sensors in the charged particle beam device measure multiple disturbances of multiple physical quantities that affect the beam offset of the charged particle beam on the sample stage, such as the alignment offset and / or focal offset. Each sensor output is supplied, containing multiple sensor signals supplied by the multiple sensors. The sensor output indicates the value of the physical quantity; that is, the sensor output is associated with the disturbance. The disturbances may overlap with each other or may be correlated with each other.

[0122] In principle, multiple sensors can be arranged in different configurations. Examples of these arrangements will be discussed later in relation to Figures 12 and 13.

[0123] Next, in box 6210, one or more compensation signals are determined to suppress such beam offset. This is based on the sensor outputs of multiple sensors. More specifically, disturbances are estimated from the sensor outputs, and these disturbances are converted into one or more compensation signals.

[0124] The above describes embodiments that facilitate the determination of such compensation signals using, for example, transfer functions, models, data-driven models using machine learning or analytical models, functional dependencies, and machine learning algorithms that can be implemented by lookup tables.

[0125] It is also possible to determine the predicted component of the beam offset in order to reduce latency, apply a compensation signal, and provide more accurate compensation.

[0126] In some scenarios, instead of determining a compensation signal to actively compensate for beam offset during operation of the charged particle beam device, for example in imaging or manipulation mode, metadata indicating one or more compensation operations to suppress beam offset in the imaging data is determined. This enables post-processing of the imaging data (see box 6015 in Figure 7). Here, beam offset compensation is performed when digitally post-processing the imaging data acquired using the charged particle beam device, in lieu of or in addition to compensating for at least some of the beam offset during operation.

[0127] The reliability of each image data can be determined. A log file can be generated to store disturbances or, specifically, one or more compensation signals.

[0128] In box 6211, optionally, the accuracy of the operation of the charged particle beam device during the prediction period can be predicted based on the sensor output and / or one or more compensation signals determined in box 6210. This may be equivalent to predicting the level of disturbance. For example, a recurrent neural network or LSTM can be used to make such a prediction. In this case as well, such a prediction may be based on a characteristic fingerprint of recurring disturbance events, as described in relation to Figure 9. Unlike what is described in relation to Figure 9, such a prediction of the level of accuracy may not directly affect the compensation signals. In some cases, the prediction may not be accurate enough to determine the predicted component of one or more compensation signals. Even in such scenarios, it is possible to predict the accuracy. In some embodiments, such accuracy is output to the user via the HMI, who can then decide whether to abort the operation or not. In other embodiments, the accuracy prediction is used in the context of box 6215.

[0129] In some cases, a scenario occurs where a disturbance exceeds or is predicted to exceed a certain predetermined threshold (see box 6211). If the disturbance exceeds the predetermined threshold, such a disturbance is considered uncompensable.

[0130] Therefore, in box 6215, it is checked whether one or more predetermined events are detected in the sensor outputs of multiple sensors. In some embodiments, such one or more predetermined events are associated with at least one of several disturbances that exceed a certain predetermined threshold. This corresponds to the sensor output that exceeds each threshold. In further embodiments, it is checked whether one or more compensation signals exceed a certain threshold. Another example of such one or more predetermined events is the detection of anomalies in the sensor outputs. In some embodiments, an anomaly detection algorithm is used. Examples include cluster-based anomaly detection or autoencoder neural networks. Such anomaly detection algorithms can be trained in an unsupervised manner.

[0131] If one or more predetermined events are not detected in box 6215, box 6205 is re-executed, i.e., the disturbance is measured again and a compensation signal is further applied. On the other hand, if an excessive disturbance is detected in box 6215, the beam is blanked in box 6220. For example, the inspection mode or manipulation mode is terminated. Alternatively, or in addition to this, a warning message is output via the HMI. In some embodiments, the output of each sensor connected to the execution of box 6220 is logged. According to some embodiments, a safe mode is entered that can be manually terminated by the user.

[0132] Beam blanking is performed with relatively low latency to avoid damage. For example, typically determining one or more compensation signals would take a considerable amount of time, for instance, to perform a search operation or to calculate the compensation signals. Therefore, in some embodiments, beam blanking is performed with a latency lower than such determination of one or more compensation signals.

[0133] In principle, the decision in box 6215 is based on sensor signals other than those considered by the logic of box 6210, according to some embodiments. For example, the following physical quantities have been found to be particularly suitable for detecting excess disturbances in box 6215: namely, acoustic vibration, vibration, ambient pressure, and ambient pressure change. On the other hand, the following physical quantities have been found to be particularly suitable for determining one or more compensation signals to suppress beam offset: namely, magnetic field, ambient temperature, ambient pressure, and ambient pressure change.

[0134] Figure 11 schematically shows an exemplary embodiment of a charged particle beam device, such as the charged particle beam device 100 described above. The scenario in Figure 11 relates to a charged particle beam repair device (or simply a repair device). Figure 11 shows schematic cross-sectional views of some key components of one embodiment of a repair device 11120 that can be used to identify and repair defects 11160 in a photolithography mask. For example, a sample 11405 in the form of a photolithography mask 11110 can be placed on a sample stage 11402 (corresponding to a sample stage 113). The photomask may have one or more defects 11160 in the form of excess material ("dark defects") and / or missing material ("light defects"). Defects in the photolithography mask are not reproduced in Figure 11. Defects, or generally defects in excess or missing material, can be scanned using a charged particle beam and thus analyzed. Alternatively, defects can be corrected using a particle beam-induced processing process. For this purpose, the repair device 11120 includes a scanning electron microscope (SEM) 11410. Furthermore, defects in excess material can be repaired using the measuring tip of a scanning probe microscope 11480. Therefore, the repair device 11120 includes one or more scanning probe microscopes 11480, typically in the form of an atomic force microscope (AFM) 11480.

[0135] In the SEM 11410 shown in Figure 11, an electron gun acting as a beam source 11412 generates an electron beam 11415, which is then directed / deflected as a focused electron beam 11415 onto a sample 11405 at location 11422 by an imaging element (not shown in Figure 11, acting as a beam deflection unit) located in the electron column 11417. This sample may include a photolithography mask, as previously described. The sample 11405 is placed on a sample stage 11402, also referred to in the art as a "stage". As indicated by the arrows in Figure 11, a positioning unit 11407 can move the sample stage 11402 around six axes relative to the column 11417 of the SEM 11410. The movement of the sample stage 11402 by the positioning unit 11407 can be performed, for example, using a micromanipulator (not shown in Figure 11).

[0136] At processing location 11422, a particle beam 11415 is incident on sample 11405. Therefore, the positioning unit 11407 enables the analysis of defects in the photomask (inspection) by first generating an image of the defects through the displacement of the sample stage 11402 perpendicular to the beam axis of the electron beam 11415. For this purpose, the imaging element of column 11417 of the SEM 11410 can scan the electron beam 11415 over sample 11405. Using the tilting and / or rotation of the 6-axis sample stage 11402, the sample stage 11402 allows inspection of one or more defects from different angles or viewpoints. The position of each of the various axes of the sample stage 11402 can be measured by interference spectroscopy (not reproduced in Figure 11). The positioning unit 11407 is controlled by signals from control unit 11425. The control unit 11425 can be part of the computer system 11430 of the repair device 11120. In some embodiments, the control unit 11425 implements the control unit 119 or the control unit 130 (see Figure 6).

[0137] The repair device 11120 further includes one or more sensors that enable characterization of both the current state of the SEM410 and the process environment (e.g., a vacuum environment) in which the SEM11410 is being used. For example, vibration, temperature, pressure, and their respective differences or (time-dependent) rates of change can be measured.

[0138] The electron beam 11415 can also be used to induce particle beam-induced processing processes to correct identified defects, for example, in the context of electron beam-induced etching (EBIE) processes to remove dark defects and / or electron beam-induced deposition (EBID) processes to correct light defects. Furthermore, in the repair device 11120 of Figure 11, the electron beam 11415 can be used to analyze the repair locations on the photomask.

[0139] Electrons backscattered from the electron beam 11415 by sample 11405 and secondary electrons generated by the electron beam 11415 in sample 11405 are recorded by detector 11420. If sample 11405 includes a photomask, detector 11420 identifies secondary electrons emitted during scanning of an absorption strip placed on the photomask for lithography. Detector 11420 located within electron column 11417 is called an "in-lens detector". In various embodiments, detector 11420 can be located within column 11417. Detector 11420 can also be used to detect electrons backscattered from one or more defects 11160 in the mask 11110. Detector 11420 is controlled by control unit 11425 of the computer system 11430 of device 120. For example, computer system 11430 may implement control unit 130. It is also possible that an integrated control unit 119 is implemented by control unit 11425.

[0140] The repair device 11120 may include a second detector 11445. The second detector 11445 is specifically designed to detect electromagnetic radiation in the X-ray range. As a result, the second detector 11445 allows for the analysis of the material composition of a sample, such as a photolithography mask, i.e., its substrate, absorption strip, and / or one or more defects. The detector 11445 is also controlled by a control unit 11425.

[0141] A control unit 11425 of the computer system 430 (which may be separate from the computer system 430) can set parameters for the electron beam 11415 to induce a deposition process for removing light defects and / or an EBIE process for etching dark defects.

[0142] Furthermore, the computer system 11430 has an evaluation unit 11435. The evaluation unit 11435 receives measurement data from detectors 11420 and 11445. From the measurement data, for example from secondary electron contrast data, the evaluation unit 11435 can generate an image in grayscale representation or grayscale value representation to be displayed on monitor 11432. In addition, the computer system 11430 includes an interface 11437 through which the computer system 11430 can transmit to further processing devices. The computer system 11430 of the repair device 11120 can also receive one or more processed or evaluated images and / or one or more superimposed images from the evaluation device.

[0143] As already described above, the electron beam 11415 of the improved SEM 11410 can be used to induce electron beam-induced processing / manipulation. Similarly, as already described above, defects in sample 11405 can be repaired using electron beam-induced manipulation. To perform these processes, the scanning electron microscope 11410 in the example of the repair device 11120 in Figure 11 has three different feed containers 11450, 11460 and 11470.

[0144] The first supply container 11450 stores a first precursor gas in the form of a deposition gas, such as a metal carbonyl, such as chromium hexacarbonyl (Cr(CO)6), or a carbon-containing precursor gas such as pyrene. Using the precursor gas stored in the first supply container 11450, the material can be deposited on the sample 11405 or mask by a local chemical reaction with the electron beam 11415 of the SEM 11410, which acts as an energy source, to split the precursor gas stored in the first supply container 11450 into chromium atoms and carbon monoxide molecules, preferably at the locations where material is intended to be deposited, i.e., at the locations of light defects. This means that an EBID process for correcting defects in the photomask is carried out by the combined supply of the electron beam 11415 and the precursor gas. The first supply container 11450 or the improved SEM 11410 combined with the volume gas stored therein forms a repair device 11120.

[0145] In the repair device 11120 shown in Figure 11, the second supply container 11460 stores a precursor gas in the form of an etching gas that enables the implementation of a local electron beam-induced etching (EBIE) process. The electron beam-induced etching process can be used to remove excess material defects or dark defects from the photolithography mask 11110 (or other samples, e.g., semiconductor wafers). The precursor gas in the form of an etching gas may include, for example, xenon fluoride (XeF2), chlorine (Cl2), oxygen (O2), ozone (O3), water vapor (H2O), hydrogen peroxide (H2O2), nitrous oxide (N2O), nitric oxide (NO), nitrogen dioxide (NO2), nitric acid (HNO3), ammonia (NH3), or sulfur hexafluoride (SF6), or a combination thereof. Thus, the improved SEM 11410, in combination with the second supply container 11460 or the precursor gas stored therein, forms the repair device 11120.

[0146] The third supply container 11470 can store an additive gas, which can be added, if necessary, to the etching gas maintained in the second supply container 11460 or to the deposition gas stored in the first supply container 11450. Alternatively, the third supply container 11470 can store a precursor gas in the form of a second deposition gas or a second etching gas.

[0147] In the scanning electron microscope 11410 shown in Figure 11, each of the supply containers 11450, 11460, and 11470 has its own control valves 11452, 11462, and 11472 to monitor or control the amount of the corresponding gas supplied per unit time, i.e., the gas volumetric flow rate at the injection site 11422 of the electron beam 11415 on the sample 11405. The control valves 11452, 11462, and 11472 are controlled and monitored by the control unit 11425. This means that partial pressure conditions for one or more gases supplied to the processing site 11422 for performing EBID and / or EBIE processes (see box 6010 in Figure 7) can be set over a wide range during operation.

[0148] Further, in the SEM 11410 exemplified in FIG. 11, each of the supply containers 11450, 11460 and 11470 has its own gas supply pipe system 11454, 11464 and 11474 terminating at nozzles 11456, 11466 and 11476, respectively, in the vicinity of an incident point, that is, the processing location 11422 of the electron beam 11415 on the sample 11405.

[0149] The supply containers 11450, 11460 and 11470 may have respective temperature setting elements and / or control elements that enable both cooling and heating of the corresponding supply containers 11450, 11460 and 11470. This makes it possible to store, and in particular supply, precursor gases of deposition gas and / or etching gas at an optimal temperature in each case (not shown in FIG. 11). The control unit 11425 can control the temperature setting elements and the temperature control elements of the supply containers 11450, 11460 and 11470. During EBID and EBIE processing processes, the temperature setting elements of the supply containers 11450, 11460 and 11470 can also be used to set the vapor pressure of the process gas stored therein by selecting an appropriate temperature.

[0150] The device 11400 may include a plurality of supply containers 11450 for storing two or more precursor gases of deposition gas. Also, the device 400 may include a plurality of supply containers 11460 for storing two or more precursor gases of etching gas.

[0151] The scanning electron microscope 11410 shown in FIG. 11 can be operated under ambient conditions or in a vacuum chamber 11442. Carrying out the EBID and EBIE processes requires a negative pressure in the vacuum chamber 11442 that is relative to ambient pressure. For this purpose, the SEM 11410 of FIG. 11 includes a pump system 11444 for generating and maintaining the required negative pressure in the vacuum chamber 11442. With the control valves 11452, 11462 and 11472 closed, in the vacuum chamber 11442 <10 -4A residual gas pressure of Pa is obtained. The pump system 11444 may include separate pump systems (not shown in Figure 11) for the upper part of the vacuum chamber 11442 for supplying the electron beam 11415 of the SEM 11410 and for the lower part of the reaction chamber 11448. Pressure sensors may be provided to monitor the pressure inside and outside the vacuum chamber 11442. The pressure difference may also be monitored.

[0152] The SEM 11410 shown in the repair device 11120 of Figure 11 has a single electron beam 11415. However, it is also possible for the SEM 11410 to have a second particle beam source. The second particle beam may include a photon beam and / or an ion beam (not shown in Figure 11). Furthermore, the SEM 11410 may have two or more electron beams 11415 so that two or more particle beam-induced processing processes or two or more analytical processes for two or more defects can be performed in parallel.

[0153] Furthermore, the exemplary repair device 11120 shown in Figure 11 includes a scanning probe microscope 11480, which is implemented in the form of a scanning force microscope (SFM) 11480 or an atomic force microscope (AFM) 11480. The scanning probe microscope 11480 can be used to scan one or more defects 11160 of the sample 11405 or of the photomask 11110. The scanning probe microscope 11480 can also be used to repair defects in excess material. For this purpose, the scanning probe microscope 11480 may include a first measuring tip for analyzing the sample 11405 and a second measuring tip for processing one or more defects.

[0154] Figure 11 shows only the measuring head 11485 of the scanning probe microscope 11480 in the repair device 11120. In the embodiment of Figure 11, the measuring head 11485 includes a holding device 11487. The measuring head 11485 is fixed to the frame of the repair device 11120 using the holding device 11487 (not shown in Figure 11). A piezoelectric actuator is attached to the holding device 11487 of the measuring head 11485, enabling the free end of the piezoelectric actuator 11490 to move in three spatial directions (not shown in Figure 11). A probe 11492, including a cantilever 11494 or lever arm 11494 and a measuring tip 11495, is fixed to the free end of the piezoelectric actuator 11490. The free end of the cantilever 11494 of the probe 1192 has a measuring tip 11495.

[0155] Next, relating to Figures 12 and 13, we disclose options for positioning sensors 800 that can be used to measure disturbances of physical quantities affecting the beam offset of beam 11415 of the repair device 11120. The repair device 11120 is shown only schematically in Figures 12 and 13, with a higher level of abstraction compared to Figure 11. In addition to those disclosed in Figure 11, Figures 12 and 13 also disclose a beam blanker 11801 that can be used to blank beam 11415, an aperture 11802 for deflecting the beam (i.e., forming the optical system of beam deflection unit 112), and electric coils 11803 and 11804.

[0156] In the scenario shown in Figure 12, the sensor 800 is located outside the vacuum chamber 11442 of the repair device 11120. In the scenario shown in Figure 13, the sensor 800 is located inside the vacuum chamber 11442 of the repair device 11120. Combinations are also possible; that is, some sensors may be located inside the vacuum chamber, while others may be located outside the vacuum chamber.

[0157] Figures 14 and 15 illustrate the high-precision mask repair operation achievable by the repair device 11120 in the preceding figures. In the first step shown in Figure 14, mask defects 1471.1 at absorption lines 1453 on the substrate layer 1451 of the mask are determined with high precision. Using the inspection mode, a precise determination of the extent of defect 1471.1, including at least the tilt angle 1473.1 of defect 1471.1, is made. The edge position of the defect, the deviation of the edge position from the target range, and the extent of the defect can be determined with an accuracy of less than 1 nm, preferably more than 0.5 nm. The defect volume of material to be deposited in the repair operation can be determined with high precision. In the repair step (manipulation mode), defect 1471.1 is filled with, for example, chromium, using low-energy electron beam-assisted deposition of material from a precursor gas supplied by a gas supply device, thereby forming the repaired defect 1477. This is shown in Figure 15. Next, the finish of the repair operation is verified by the device in inspection mode. The resulting edge position of line 1453 and the inclination angle of the line edge 1473.2 are obtained with high precision. This ensures that the repair operation is performed very well within the mask specification requirements, including the stringent requirements for EUV masks with edge positions of less than 0.5 nm or even smaller. The repair and verification steps can also be repeated. Such manipulation is not limited to defective material in the mask layer, but is equally applicable to the removal of excess material in the mask layer. Furthermore, the manipulation is not limited to mask repair, but can also be applied to circuit modification operations on processed wafers. In both embodiments, the layer material is removed by electron beam-induced etching or deposited by electron beam-induced deposition, and high-precision endpoint detection of the processing is required.

[0158] Figure 16 schematically shows an example embodiment of a charged particle beam device, such as the charged particle beam device 100 described above.

[0159] The charged particle beam device 161001 in Figure 16 is an aberration-reducing low-energy corrected electron microscope, as described in German Patent Application No. 102019214936, filed on September 27, 2019, which is incorporated herein by reference. Generally, low-energy corrected electron microscopes include means for correcting chromatic aberration (CC), spherical aberration (CS), and optionally further field curvature (FC). The low-energy corrected single-beam charged particle microscope 161001 includes a beamlet generator 161301 for generating a single primary charged particle beamlet 161003 and an object irradiation unit 161100 for irradiating an image subfield on the surface of a sample 11110 (e.g., a lithography mask or a semiconductor wafer containing a semiconductor structure) placed on the objective plane 16101, thereby generating a secondary electron beamlet 161009 that, when in use, emanates from the focal point 161605 of the primary beamlet 161003 within the image subfield. The subfield typically has a lateral range of at least 5 μm, preferably 8 μm, and 12 μm or more. The object illumination unit 161100 further includes first to third electrostatic or magnetic lenses 161403, 161405, and 161407 and an objective lens 161102. The charged particle microscope 16100 further includes a detection unit 161200 for acquiring a digital image of the image subfield of the sample surface when in use. The detection unit 161200 includes an electronic sensor 161207 and optionally an electrostatic or electromagnetic deflection element 161205. The charged particle microscope 161001 further includes an electromagnetic beam split system 161400 for guiding the primary beamlet 161003 along the primary beam path (solid line 161013) and the secondary beamlet 161009 along the secondary beam path (dashed line 161011). The secondary beamlet 161009, collected by the objective lens 161102, propagates in the opposite direction to the primary beamlet 161003 and is therefore separated from the primary beamlet 161003 by the magnetic beam split system 161400. The charged particle microscope 161001 further includes a long-straw cluster scanner 161110. The raster scanner 16110 (forming a beam deflection unit) includes at least a first set of deflection electrodes 161111.The charged particle microscope 161001 further includes a control unit 16800 (implementing control unit 119 or control unit 130). The charged particle microscope 161001 further includes at least a first corrector 161601 for correcting the primary charged particle beamlet 161003. The charged particle system 161001 further includes a correction system 161052 having a second optical axis 161050 at an angle to the optical axis 16105. A beam splitter system 161400 guides the primary beamlet into the correction system 161052 in the direction of the second optical axis 161050. The correction system includes an electrostatic mirror 161414 that reflects the primary beamlet to the beam splitter system 161400. In one embodiment, a second corrector 161602 is located in the correction system 161052 together with a correction electrode 161612. The low-energy corrected single-beam charged particle microscope 161001 enables electron imaging with kinetic energies of less than 400 eV, preferably less than 300 eV, more preferably 200 eV, or even more preferably less than 150 eV, and using low incident energy primary electrons and correction means for the low-energy electron microscope, a high resolution of less than 2 nm, preferably less than 1.5 nm, and more preferably 1 nm is achieved.

[0160] In this case as well, the charged particle beam is placed inside a vacuum chamber (not shown in Figure 16). The sensor can be placed inside and / or outside the vacuum chamber, as previously mentioned in relation to Figures 14 and 15.

[0161] In summary, this invention discloses a technique for facilitating the compensation of multiple disturbances, each caused by multiple physical quantities, that affect the beam offset of a charged particle beam device. Such compensation is performed during imaging or manipulation modes, for example, for mask repair or circuit addition. Such compensation is possible, in particular, when the disturbance / beam offset is within a predetermined range. Otherwise, if the disturbance cannot be compensated, according to the embodiment, the imaging or manipulation mode is stopped, for example, by blanking the beam and / or closing the precursor gas supply valve. According to the embodiment, a warning is issued. After the disturbance is resolved, operation resumes from the point in time when the process was stopped. By using the technique disclosed herein, improvements in the quality of imaging or manipulation operations can be obtained. The risk of damaging expensive lithography masks or semiconductor devices being manipulated can be reduced.

[0162] Furthermore, a technique is disclosed to facilitate the use of sensor outputs from multiple sensors for predicting the future behavior of charged particle beam devices. For example, sensor outputs can be stored in a data repository, and multiple time series can be correlated with each other. Correlations can be found, and repeating fingerprints can be identified. This can be used to make predictions about the future behavior of charged particle beam devices. For example, predictive maintenance information can be obtained by acquiring the acoustic frequency spectrum and / or acoustic noise pressure using a microphone, and a continuously rising noise level at a specific frequency in the acoustic spectrum, for example, may indicate a failure of one or more components of the charged particle beam device, such as a pump.

[0163] In various implementations, sensor outputs are analyzed using machine learning algorithms such as deep neural networks. Training can be repeated periodically based on training data acquired during calibration mode, thus continuously improving accuracy. Furthermore, field-specific training based on field-specific calibration becomes possible.

[0164] In summary, at least the following embodiments, as defined by the following items, have been disclosed.

[0165] Item 1. A charged particle beam device comprising a beam source, a beam deflection unit, and a sample stage, wherein the beam deflection unit is configured to deflect a beam of charged particles emitted from the beam source to position the beam on the sample stage, and the charged particle beam device comprises, - One or more sensors, each configured to measure one or more disturbances of one or more physical quantities that affect the beam offset of the beam on the sample stage, - At least one control unit configured to determine one or more compensation signals to suppress beam offset based on the sensor output of one or more sensors, A charged particle beam device comprising, wherein at least one control unit is configured to supply one or more compensation signals to at least one of a beam source, a beam deflection unit, a sample stage, or one or more compensation modules.

[0166] Item 2. A charged particle beam device according to Item 1, A charged particle beam device in which at least one control unit is configured to determine a predicted component of the beam offset based on the sensor outputs of one or more sensors, and to determine one or more compensation signals based on the predicted component of the beam offset.

[0167] Item 3. A charged particle beam device according to Item 2, The sensor output of at least one of the one or more sensors includes its respective time-series data. A charged particle beam device in which at least one control unit is configured to determine a predictive component based on time-series data of the sensor output of at least one of one or more sensors.

[0168] Item 4. A charged particle beam device as described in Item 3, A charged particle beam device in which the analysis of time series data includes finding the fingerprint of one or more predetermined disturbance events in the time series data and / or applying a recurrent neural network such as a long short-term memory network.

[0169] Item 5. A charged particle beam device as described in Item 4, At least one control unit is configured to selectively initiate the calibration phase. A charged particle beam device in which, when operating in the calibration phase, at least one control unit is configured to place fingerprints of one or more disturbance events into a repository, based on at least one of the following: identifying each iteration of a fingerprint in time-series data, or obtaining user input data indicating each of one or more disturbance events.

[0170] Item 6. A charged particle beam device as described in Item 4 or 5, At least one control unit is configured to selectively initiate the calibration phase. A charged particle beam device in which, when operating in the calibration phase, at least one control unit is configured to train a predictive model based on time-series data measured during the calibration phase in order to find a fingerprint and thereby enable the predictive model to determine the predictive components.

[0171] Item 7. A charged particle beam device as described in any one of the preceding items, A charged particle beam device, wherein at least one control unit is further configured to predict the accuracy of the operation of the charged particle beam device during a prediction period based on sensor outputs or at least one of one or more compensation signals.

[0172] Item 8. A charged particle beam device as described in Item 7, A charged particle beam device, wherein at least one control unit is further configured to selectively halt the operation of the charged particle beam device depending on the precision of the operation, for example by blanking the beam.

[0173] Item 9. A charged particle beam device as described in any one of the preceding items, A charged particle beam device in which one or more disturbances include multiple disturbances, and at least one control unit is configured to determine one or more compensation signals based on the cross-dependencies between the multiple disturbances.

[0174] Item 10. A charged particle beam device as described in Item 9, A charged particle beam device in which at least one control unit is configured to determine one or more compensation signals based on the cross-dependency between temperature-induced disturbances and pressure-induced disturbances.

[0175] Item 11. A charged particle beam device as described in any one of the preceding items, A charged particle beam device in which at least one control unit is configured to determine one or more compensation signals based on a pre-trained algorithm.

[0176] Item 12. A charged particle beam device as described in Item 11, The pre-trained algorithms include deep neural networks such as convolutional neural networks, and are used in charged particle beam devices.

[0177] Item 13. A charged particle beam device as described in Item 11, A charged particle beam device with pre-trained algorithms, including machine learning algorithms.

[0178] Item 14. A charged particle beam device as described in any one of the preceding items, wherein at least one control unit is configured to determine one or more compensation signals based on pre-parameterized functional dependencies.

[0179] Item 15. A charged particle beam device as described in any one of the preceding items, A charged particle beam device in which at least one control unit is configured to determine one or more compensation signals using a lookup table that links sensor outputs to one or more compensation signals.

[0180] Item 16. A charged particle beam device as described in Item 15, A charged particle beam device from which a lookup table is retrieved from a device-specific repository associated with the charged particle beam device.

[0181] Item 17. A charged particle beam device as described in Item 15, A charged particle beam device from which a lookup table is retrieved from a cloud storage repository associated with multiple charged particle beam devices.

[0182] Item 18. A charged particle beam device as described in any one of the preceding items, A charged particle beam device in which multiple physical quantities are selected from a group including acoustic vibrations, vibrations, pressure, humidity, temperature, laminar flow, turbulent flow, differential quantities, rates of change of physical quantities, vector quantities, and scalar quantities.

[0183] Item 19. A charged particle beam device as described in any one of the preceding items, A charged particle beam device comprising one or more sensors, including at least one sensor for measuring the temperature or pressure of a coolant.

[0184] Item 20. A charged particle beam device as described in any one of the preceding items, A charged particle beam device in which at least one of one or more sensors is located inside the vacuum chamber of the charged particle beam repair device.

[0185] Item 21. A charged particle beam device as described in any one of the preceding items, A charged particle beam device in which at least one of one or more sensors is located outside the vacuum chamber of the charged particle beam device.

[0186] Item 22. A charged particle beam device as described in any one of the preceding items, A charged particle beam device comprising one or more sensors, including at least one sensor for measuring a pressure difference or temperature difference between two or more components of the charged particle beam repair device.

[0187] Item 23. A charged particle beam device as described in any one of the preceding items, A charged particle beam device in which one or more disturbances affect the beam offset by deflecting the beam, selected from a group consisting of direct disturbances, and indirect disturbances, which affect the beam offset by affecting one or more components of the charged particle beam device.

[0188] Item 24. A charged particle beam device as described in any one of the preceding items, A charged particle beam device in which the beam offset includes at least one of a position offset or a focus offset.

[0189] Item 25. A charged particle beam device as described in any one of the preceding items, A charged particle beam device in which at least one control unit is configured to monitor the sensor output of at least one of one or more sensors or the additional sensor output of at least one additional sensor, and to selectively blank the beam based on that monitoring.

[0190] Item 26. A charged particle beam device as described in Item 25, A charged particle beam device in which at least one control unit is configured to selectively blank the beam with less latency compared to the above determination of one or more compensation signals.

[0191] Item 27. A charged particle beam device as described in any one of the preceding items, A charged particle beam device wherein at least one control unit is configured to supply one or more compensation signals by the charged particle beam device operating in a manipulation mode such as electron beam-induced etching or deposition mode, the manipulation mode includes repairing or modifying a semiconductor device on a wafer mounted on a sample stage.

[0192] Item 28. A charged particle beam device as described in any one of the preceding items, A charged particle beam device is a charged particle beam repair device.

[0193] Item 29. A charged particle beam device as described in any one of the preceding items, A charged particle beam device in which the charged particles are electrons or ions such as helium ions or neon ions.

[0194] Item 30. A charged particle beam device as described in any one of the preceding items, A charged particle beam device is a composite focused ion beam electron microscope cross-beam device.

[0195] Item 31. A charged particle beam device as described in any one of the preceding items, wherein the charged particle beam device is a charged particle beam repair device, and the charged particle beam repair device further includes a precursor gas source. A charged particle beam device comprising at least one control unit configured to supply control signals to a beam source, a beam deflection unit, and a precursor gas source for performing electron beam-induced manipulation of a sample mounted on a sample stage, and at least one control unit configured to supply one or more compensation signals during the electron beam-induced manipulation.

[0196] Item 32. A charged particle beam device according to any one of the preceding items, wherein at least one control unit is configured to supply the one or more compensation signals while the charged beam device is operating in an imaging mode which includes imaging the structure of the sample mounted on a sample stage.

[0197] Item 33. A charged particle beam device as described in any one of the preceding items, A charged particle beam device in which at least one control unit determines one or more compensation signals according to the linear or nonlinear dependence of one or more compensation signals on the sensor output.

[0198] Item 34. A charged particle beam device as described in any one of the preceding items, One or more disturbances include multiple disturbances, A charged particle beam device in which one or more physical quantities include multiple physical quantities.

[0199] Item 35. A charged particle beam device as described in any one of the preceding items, A charged particle beam device in which one or more compensation modules are selected from a group including a coil for applying a magnetic field, an external field plate for applying an electric field, a pair of Helmholtz coils, an active cooling or heating element, an active attenuation element, and a pressure control element such as a pump, located outside the vacuum chamber or housing of the charged particle beam device.

[0200] Item 36. A charged particle beam device comprising a beam source, a beam deflection unit, and a sample stage, wherein the beam deflection unit is configured to deflect a beam emitted from the beam source to position the beam on the sample stage, and the charged particle beam device comprises, - One or more sensors, each configured to measure one or more disturbances of one or more physical quantities that affect the beam offset of the beam on the sample stage, A charged particle beam device comprising at least one control unit configured to determine metadata indicating one or more compensation operations to suppress beam offset in image data acquired by a charged particle beam device operating in imaging mode, based on the sensor outputs of one or more sensors, and to store the metadata in association with the image data.

[0201] Item 37. A charged particle beam device as described in Item 36, A charged particle beam device in which one or more compensation operations are selected from a group including image shift, rotation, skew, contrast enhancement, and blur reduction.

[0202] Item 38. - Monitoring physical quantities that cause disturbances to the beam of charged particle beam devices, - A method that includes compensating for disturbances based on the above monitoring.

[0203] Item 39. The method described in Item 38, A method for compensating for disturbances, comprising applying a voltage or current to the electron optical system of a beam deflection unit of an electro-particle beam device in order to move the beam in the opposite direction to the beam offset caused by the disturbance.

[0204] Item 40. The method described in Item 38 or 39, A method for compensating for or reducing disturbances, comprising moving the sample stage of a charged particle beam device in the direction of the beam offset caused by the disturbance.

[0205] Item 41. A method according to any one of items 38-40, wherein the time latency between the monitoring and the compensation or reduction is less than 50 milliseconds, optionally less than 500 milliseconds, and optionally less than 5 seconds.

[0206] Item 42. The method described in any one of items 38-41, A method in which the above compensation or reduction is performed while the charged particle beam device is operating in a manipulation mode which includes electron beam-induced etching of material from a wafer mask or electron beam-induced deposition of material onto a wafer mask.

[0207] Item 43. The method described in any one of items 38-42, - A method further comprising selectively suspending the operation of a charged particle beam device based on the above monitoring.

[0208] Item 44. The method described in Item 43, A method for selectively halting the operation of a charged particle beam device, including beam blanking.

[0209] Item 45. The method described in Item 43 or 44, A method further comprising selecting, based on the above monitoring, between performing the above compensation for disturbances and performing the above abortion.

[0210] Item 46. A method for manipulating or imaging a sample mounted on a sample stage of a charged particle beam device, wherein the charged particle beam device includes a beam source, a beam deflection unit, and a sample stage, and the beam deflection unit is configured to deflect a beam of charged particles emitted from the beam source to position the beam on the sample stage, and the method is - Acquiring the sensor output of one or more sensors of a charged particle beam device, wherein each of the one or more sensors measures one or more disturbances of one or more physical quantities that affect the beam offset of the beam on the sample stage, - Determining one or more compensation signals to suppress beam offset based on the sensor output of one or more sensors, - A method comprising supplying one or more compensation signals to a beam source, a beam deflection unit, a sample stage, or one or more compensation modules.

[0211] Item 47. The method described in Item 46, which is performed by a control unit for a charged particle beam device as described in Item 1.

[0212] Item 48. A method for post-processing image data acquired by a charged particle beam device including a beam source, a beam deflection unit, and a sample stage, wherein the beam deflection unit is configured to deflect a beam of charged particles emitted from the beam source to position the beam on the sample stage. - Acquiring sensor outputs from one or more sensors of a charged particle beam device, wherein each of the one or more sensors measures one or more disturbances of one or more physical quantities that affect the beam offset of the beam on the sample stage, - Determining metadata indicating one or more compensation operations to suppress beam offset in image data acquired by a charged particle beam device operating in imaging mode, based on the sensor output of one or more sensors, A method comprising post-processing image data according to one or more compensation operations based on metadata.

[0213] Item 49. A method according to Item 48, which is at least partially performed by a control unit for a charged particle beam device as described in Item 36.

[0214] While the present invention has been illustrated and described in relation to certain preferred embodiments, those skilled in the art will be able to conceive of equivalents and modifications by reading and understanding this specification. The present invention includes all such equivalents and modifications and is limited only by the appended claims.

[0215] For illustrative purposes, the various embodiments described above are disclosed in the context of charged particle beam repair devices that perform repair work using electron beam-induced manipulation of samples, i.e., EBID and / or EBIE. In principle, repair work using physical actions with ions, i.e., FIB etching, is also employable. Furthermore, the techniques disclosed herein are not limited to charged particle repair devices and can also be used to compensate for disturbances during inspection or measurement operations on semiconductor wafers during circuit modification operations or operation in imaging mode of each imaging charged particle beam device.

[0216] For illustrative purposes, the various embodiments described above are disclosed in the context of charged particle beam devices employing charged particles such as electrons or ions. Similarly, the techniques disclosed herein can also be applied to uncharged particle beam devices, for example, for photon-based microscopes. In this case, disturbances may be caused by physical quantities such as seismic vibrations, acoustics, pressure changes, wind speed changes, humidity changes, and temperature. Each beam device can be, for example, a laser, an X-ray inspection instrument, etc. Compensation can be achieved by shifting the sample stage to suppress beam offset, as described in relation to Figures 1 to 5.

[0217] Furthermore, techniques for active compensation of beam offset caused by disturbances of physical quantities are disclosed. Such techniques can be applied in conjunction with passive shielding. For example, acoustic vibrations, thermal drift, laminar flow, or turbulence can be reduced by sealing beam-related components of a charged particle beam device within a housing. Noise-absorbing materials are attached to the housing. Passive or active vibration damping systems can be used to support the housing on the floor.

Claims

1. A charged particle beam repair device (100, 11120, 11410, 161001) comprising a beam source (111, 11412), a beam deflection unit (112, 11417), a precursor gas source (11456, 11466, 11476, 11450, 11460, 11470, 11452, 11462, 11472), and a sample stage (114, 11402), wherein the beam deflection The deflection units (112, 11417) are configured to deflect the beam of charged particles (90, 91, 92, 93, 94, 95, 11415, 161003, 161009) emitted from the beam source in order to position the beam on the sample stage (113, 11402), and the charged particle beam repair devices (100, 11120, 11410, 161001 - Multiple sensors (121, 122, 800) each configured to measure multiple disturbances of multiple physical quantities that affect the beam offset (71, 72, 81) of the beams (90, 91, 92, 93, 94, 95) on the sample stages (114, 11402), - Includes at least one control unit (119, 130, 11425, 16800) configured to determine one or more compensation signals (165) to suppress the beam offset (71, 72, 81) based on the sensor outputs (161, 162) of the plurality of sensors (121, 122, 800), The at least one control unit (119, 130, 11425, 16800) is configured to supply control signals to the beam source (111, 11412), the beam deflection unit (112, 11417), and the precursor gas source (11456, 11466, 11476, 11450, 11460, 11470, 11452, 11462, 11472) for performing electron beam-induced manipulation of the sample (11110) attached to the sample stage (113, 11402). Charged particle beam repair device (100, 11120, 11410, 161001) wherein at least one control unit (119, 130, 11425, 16800) is configured to supply one or more compensation signals (165) to at least one of the beam source (111, 11412), the beam deflection unit (112, 11417), the sample stage (114, 11402), or one or more compensation modules during electron beam-induced manipulation.

2. The charged particle beam repair device (100, 11120, 11410, 161001) according to claim 1, wherein the at least one control unit (119, 130, 11425, 16800) is configured to determine a predicted component of the beam offset (71, 72, 81) based on the sensor outputs (161, 162) of the plurality of sensors (121, 122, 800), and to determine one or more compensation signals (165) based on the predicted component of the beam offset (71, 72, 81).

3. The sensor output (161, 162) of at least one of the plurality of sensors (121, 122, 800) includes the respective time-series data (310). The charged particle beam repair device (100, 11120, 11410, 161001) according to claim 2, wherein the at least one control unit (119, 130, 11425, 16800) is configured to determine the predicted component based on the analysis of the time-series data (310) of the sensor output (161, 162) of at least one of the plurality of sensors (121, 122, 800).

4. The charged particle beam repair device (100, 11120, 11410, 161001) according to claim 3, wherein the analysis of the time series data (310) includes finding a fingerprint (312) of one or more predetermined disturbance events (311) in the time series data (310).

5. The at least one control unit (119, 130, 11425, 16800) is configured to selectively activate the calibration phase (6005), Charged particle beam repair device (100, 11120, 11410, 161001) according to claim 4, wherein when operating in the calibration phase (6005), the at least one control unit (119, 130, 11425, 16800) is configured to store the fingerprint (312) of one or more disturbance events (311) in a repository based on at least one of identifying each iteration of the fingerprint (312) in the time series data or obtaining user input data indicating each of the one or more disturbance events (311).

6. The at least one control unit (119, 130, 11425, 16800) is configured to selectively activate the calibration phase (6005), The charged particle beam repair device (100, 11120, 11410, 161001) according to claim 4, wherein when operating in the calibration phase (6005), the at least one control unit (119, 130, 11425, 16800) is configured to find the fingerprint (312) and thereby train the predictive model on the time-series data (310) measured during the calibration phase (6005) to enable the predictive model to determine the predictive component.

7. The at least one control unit (119, 130, 11425, 16800) is configured to selectively activate the calibration phase (6005), Charged particle beam repair device (100, 11120, 11410, 161001) according to claim 5, wherein when operating in the calibration phase (6005), the at least one control unit (119, 130, 11425, 16800) is configured to train the predictive model based on the time-series data (310) measured during the calibration phase (6005) in order to find the fingerprint (312) and thereby enable the predictive model to determine the predictive component.

8. The charged particle beam repair device (100, 11120, 11410, 161001) according to claim 1, wherein the at least one control unit (119, 130, 11425, 16800) is further configured to predict the accuracy of the operation of the charged particle beam repair device (100, 11120, 11410, 161001) during a prediction period based on at least one of the sensor outputs (161, 162) or the one or more compensation signals (165).

9. The charged particle beam repair device (100, 11120, 11410, 161001) according to claim 1, wherein the at least one control unit (119, 130, 11425, 16800) is configured to determine one or more compensation signals (165) based on the cross-dependency between the plurality of disturbances.

10. The charged particle beam repair device (100, 11120, 11410, 161001) according to claim 1, wherein the at least one control unit (119, 130, 11425, 16800) is configured to determine the one or more compensation signals (165) based on a pre-trained algorithm.

11. The charged particle beam repair device (100, 11120, 11410, 161001) according to claim 6, wherein at least one control unit (119, 130, 11425, 16800) is configured to determine one or more compensation signals (165) based on a pre-trained algorithm.

12. The charged particle beam repair device (100, 11120, 11410, 161001) according to claim 1, wherein the at least one control unit (119, 130, 11425, 16800) is configured to determine the one or more compensation signals based on a pre-parameterized function dependency.

13. The charged particle beam repair device (100, 11120, 11410, 161001) according to claim 1, wherein the at least one control unit (119, 130, 11425, 16800) is configured to determine the one or more compensation signals using a lookup table that links the sensor outputs (161, 162) to the one or more compensation signals (165).

14. The charged particle beam repair device (100, 11120, 11410, 161001) according to claim 1, wherein the plurality of physical quantities are selected from a group including acoustic vibration, vibration, pressure, humidity, temperature, laminar flow, turbulent flow, differential quantity, rate of change of physical quantity, vector quantity, and scalar quantity.

15. The charged particle beam repair device (100, 11120, 11410, 161001) according to claim 1, wherein the plurality of sensors (121, 122, 800) include at least one sensor for measuring the temperature or pressure of the coolant.

16. The charged particle beam repair device (100, 11120, 11410, 161001) according to claim 1, wherein at least one of the plurality of sensors (121, 122, 800) is located inside the vacuum chamber (110) of the charged particle beam repair device (100, 11120, 11410, 161001).

17. The charged particle beam repair device (100, 11120, 11410, 161001) according to claim 1, wherein the plurality of sensors (121, 122, 800) include at least one sensor for measuring a pressure difference or temperature difference between two or more components of the charged particle beam repair device (100, 11120, 11410, 161001).

18. The charged particle beam repair device (100, 11120, 11410, 161001) according to claim 1, wherein the plurality of disturbances are selected from a group including direct disturbances that affect the beam offset (71, 72, 81) by deflecting the beam, and indirect disturbances that affect the beam offset (71, 72, 81) by affecting one or more components of the charged particle beam repair device (100, 11120, 11410, 161001).

19. The charged particle beam repair device (100, 11120, 11410, 161001) according to claim 1, wherein the beam offset (71, 72, 81) includes at least one of the beam placement offset (71, 72, 81) or the focal offset (71, 72).

20. The charged particle beam repair device (100, 11120, 11410, 161001) according to claim 1, wherein the at least one control unit (119, 130, 11425, 16800) is configured to monitor the sensor output (161, 162) of at least one of the plurality of sensors (121, 122, 800) or the additional sensor output (161, 162) of at least one additional sensor, and to selectively blank the beam based on the monitoring.

21. The charged particle beam repair device (100, 11120, 11410, 161001) according to claim 1, wherein the at least one control unit (119, 130, 11425, 16800) is configured to supply the one or more compensation signals (165) while the charged particle beam repair device (100, 11120, 11410, 161001) is operating in a manipulation mode which includes repairing or correcting a semiconductor device on a wafer mounted on the sample stage (114, 11402).

22. A charged particle beam device (100, 11120, 11410, 161001) comprising a beam source, beam deflection units (112, 11417), and sample stages (114, 11402), wherein the beam deflection units (112, 11417) are configured to deflect the beam emitted from the beam source to position the beam on the sample stages (114, 11402), and the charged particle beam device (100, 11120, 11410, 161001) is configured to - Multiple sensors (121, 122, 800) each configured to measure multiple disturbances of multiple physical quantities that affect the beam offset (71, 72, 81) of the beams (90, 91, 92, 93, 94, 95) on the sample stages (114, 11402), - A charged particle beam device (100, 11120, 11410, 161001) comprising at least one control unit (119, 130, 11425, 16800) configured to determine metadata indicating one or more compensation operations to suppress the beam offset (71, 72, 81) in image data acquired by the charged particle beam device operating in imaging mode, based on the sensor outputs (161, 162) of the plurality of sensors (121, 122, 800), and to store the metadata in association with the image data.

23. A method for manipulating a sample (11110) attached to a sample stage of a charged particle beam repair device (100, 11120, 11410, 161001), wherein the charged particle beam repair device includes a beam source, a beam deflection unit, a precursor gas source, and a sample stage, and the beam deflection unit is configured to deflect a beam of charged particles emitted from the beam source to position the beam on the sample stage. - Acquiring the sensor outputs of multiple sensors of the charged particle beam repair device, wherein each of the multiple sensors measures multiple disturbances of multiple physical quantities that affect the beam offset of the beam on the sample stage, - Determining one or more compensation signals to suppress the beam offset based on the sensor outputs of the plurality of sensors, - To supply control signals to the beam source, the beam deflection unit, and the precursor gas source for performing electron beam-induced manipulation of the sample, - A method comprising supplying the one or more compensation signals to at least one of the beam source, the beam deflection unit, the sample stage, or one or more compensation modules during the electron beam-induced manipulation.

24. The method according to claim 23, as performed by the control unit of the charged particle beam repair device according to claim 1.

25. A method for post-processing image data acquired by a charged particle beam device including a beam source, a beam deflection unit, and a sample stage, wherein the beam deflection unit is configured to deflect a beam of charged particles emitted from the beam source to position the beam on the sample stage. - Obtaining sensor outputs from multiple sensors of the charged particle beam device, wherein each of the multiple sensors measures multiple disturbances of multiple physical quantities that affect the beam offset of the beam on the sample stage, - Based on the sensor outputs of the plurality of sensors, determine metadata indicating one or more compensation operations to suppress the beam offset in the image data acquired by the charged particle beam device operating in imaging mode, A method comprising post-processing the image data according to one or more compensation operations based on the metadata.

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