Computer-implemented method and apparatus for processing a sample using a nanomanipulator and computer program product

Abstract

The present invention provides a method for placing a tip (106) of a probe (1106) of a nanomanipulator (104) onto a sample (102, 1102), particularly in a vacuum. The probe (1106) includes an extension arm (108) and the tip (106) attached thereto. The nanomanipulator (104) further includes an excitation unit (1110), to which the probe (1106) is mechanically coupled. The method includes the following steps: - when the tip (106) is not in contact with the sample (102), by applying force to the excitation unit (1110). A resonant drive signal (1010) is provided to oscillate the probe (1106); - during a first approach phase, a first distance along a z-direction between the tip (106) and the sample (102) is reduced until at least one of a first set of stop conditions is met, wherein the first set of stop conditions includes detecting a shift in the frequency of the resonant drive signal (1010) used during the first approach phase; and - the first approach phase is terminated when the at least one of the first stop conditions is met, and the resonant drive signal (1010) is deactivated.

Description

Computer-implemented method and apparatus for processing samples using a nanomanipulator The present invention relates to computer-implemented methods and apparatus for processing samples using nanomanipulators. [Cross-reference] The content of priority application DE 10 2023 129 682.5 is hereby incorporated in its entirety by reference. Lithography is used to create microstructured components, such as integrated circuits. A lithography system comprising an illumination system and a projection system is used to perform the lithography process. An image of a mask (reduction mask) illuminated by the illumination system is projected by the projection system onto a substrate (e.g., a silicon wafer) coated with a photosensitive layer (photoresist) and positioned at the projection system's image plane, transferring the mask structure onto the substrate's photosensitive coating. Multiple exposures are performed using a photomask (also known as a lithography mask) because it is crucial that the mask be free of defects and contamination. Therefore, significant effort is required to inspect the lithography mask for defects and contamination. Attempts are then made to repair identified defects or remove contaminants. Defects and contaminants can be extremely small, measuring in the order of nanometers. Therefore, removing these defects and contaminants requires equipment with very high spatial resolution. Contaminants are tiny particles, such as those from the surrounding environment, that deposit on the photomask. For example, if the photomask is transferred between different processing tools, the incidence of this type of contamination increases. These particles have a wide variety of properties and come in various sizes and / or shapes. These particles can be, for example, metal particles, particularly tin, but can also be ceramic particles, polymer particles, and other carbon compounds. The particles are typically adsorbed onto the photomask surface, meaning that there is no strong chemical bond, such as an atomic bond, between the particle material and the photomask surface. If the attractive forces acting to dislodge the particle (e.g., Coulomb and van der Waals forces) are greater than the attractive forces acting on the reticle surface (e.g., Coulomb and van der Waals forces), the particle will leave the reticle surface. Depending on the type of interaction between the particle and the reticle surface, activation energy may be required to break the existing bond to the reticle surface. Processing devices are known that can remove individual particles from surfaces in a targeted manner. For example, nanomanipulators, such as atomic force microscopes, are used for this purpose. In this case, the particles are picked up by the measuring tip (measuring and manipulator tip) of the nanomanipulator, adhere to the measuring tip, and are removed from the mask surface. Imaging methods (e.g., image recording using a scanning electron microscope and / or a scanning ion microscope) usually support particle removal and require the user to operate at the nanoscale. In this case, even small user errors can easily lead to damage or destruction of the nanomanipulator or the measuring tip of the sample. Furthermore, this process requires a high degree of user concentration, which increases the risk of user errors due to fatigue. Furthermore, sample processing (in particular, particle removal from the sample) is made more difficult by the fact that the precise position of the measuring tip's apex is unknown. In particular, the measuring tip's apex is the point and / or region of the measuring tip that makes initial contact with the sample or a particle on the sample as the measuring tip approaches the sample and / or the particle. Typically, the actual apex of the measuring tip is not visible in images of the sample with the measuring tip (e.g., scanning electron microscope images and / or scanning ion microscope images), and therefore the lateral position of the apex cannot be determined independently from such images. Furthermore, due to the deflection of the extension arm that holds the measuring tip, the height position of the measuring tip's apex (i.e., the distance from the sample) is also typically not precisely known. Against the above background, an object of the present invention is to improve the process of manipulating samples using a nanomanipulator. Therefore, a method for positioning a tip (106) of a probe of a nanomanipulator on a sample, in particular in a vacuum, is provided. The probe comprises an extension arm and the tip attached thereto. The nanomanipulator further comprises an excitation unit, the probe being mechanically coupled to the excitation unit. The method comprises the following steps: - oscillating the probe by providing a resonant drive signal to the excitation unit when the tip is not in contact with the sample; - reducing a first distance between the tip and the sample in a z-direction during a first approach phase until at least one of a first set of stop conditions is met, wherein the first set of stop conditions comprises detecting a shift in the frequency of the resonant drive signal used during the first approach phase; and - terminating the first approach phase when the at least one of the first set of stop conditions is met, and deactivating the resonant drive signal. This method can be used alone or in combination with one or more of the other methods disclosed below. Optionally, the method further includes: further reducing the first distance during a second approach phase until at least one second stop condition in a second set of stop conditions is met, wherein the second set of stop conditions includes detecting a deflection of the extending arm; and terminating the second approach phase at a contact position when the at least one second stop condition in the second set of stop conditions is met. Optionally, a combination of a coarse drive and a fine drive is used to control the position of at least one of the probe or the sample along the z-direction. Optionally, the method includes: operating the fine drive to increase the first distance to move the tip from the contact position to a partially retracted position; and operating the coarse drive to reduce or increase the first distance based on a second distance between the contact position and the partially retracted position along the z-direction; and operating the fine drive to reduce the first distance to return the tip to the contact position or to a predetermined position at a third distance from the contact position along the z-direction. Optionally, the method further comprises determining at least one parameter of a resonance characteristic of the probe when the tip is not in contact with the sample, the at least one parameter comprising at least one of a resonant frequency of the probe, a Q value of the probe, and a phase angle between the resonant drive signal and a detected deflection signal associated with oscillation of the probe. Optionally, the first set of stop conditions includes at least one of the following conditions: - a frequency control signal (e.g., dF) indicating an offset in the frequency of the resonant drive signal exceeds a first critical value; - a frequency control signal (e.g., dF) indicating an offset in the frequency of the resonant drive signal is lower than a second critical value; - an amplitude feedback signal (e.g., A) for amplitude control of the resonant drive signal exceeds a third critical value; - an amplitude feedback signal (e.g., A) for amplitude control of the resonant drive signal is lower than a fourth critical value; - a phase signal indicating the relationship between the resonant drive signal and the detected oscillation of the probe exceeds a fifth critical value and / or is lower than a sixth critical value; and / or - a drive speed along the z-direction exceeds a seventh critical value and / or is lower than an eighth critical value. Optionally, the positioning of the probe is terminated in the first approach phase when at least one of the following conditions is met: the frequency control signal is lower than the second critical value; the amplitude feedback signal exceeds the third critical value; the phase signal exceeds the fifth critical value and / or is lower than the sixth critical value; and / or the driving speed exceeds the seventh critical value and / or is lower than the eighth critical value. Optionally, the second set of stop conditions further includes: - a first deflection signal (e.g., DFL) indicating a deflection of the probe along the z-direction exceeds a ninth critical value; - a second deflection signal (e.g., LAT) indicating a lateral deflection of the probe exceeds a tenth critical value; - a sum signal (e.g., SUM) indicating a combined deflection of the probe exceeds an eleventh critical value; and / or - a driving speed along the z-direction exceeds a twelfth critical value and / or is lower than a thirteenth critical value. Optionally, the seating of the probe is terminated in the second approaching stage when at least one of the following conditions is satisfied: the driving speed exceeds the twelfth threshold value and / or is lower than the thirteenth threshold value. According to another embodiment, an apparatus is provided. The apparatus includes: a sample carrier for holding a sample; a nanomanipulator including a positioning unit and an actuation unit, the positioning unit configured to move a probe including a protruding arm and a tip attached thereto; the actuation unit configured to oscillate the probe based on a drive signal; a protruding arm deflection detection system configured to detect a plurality of deflections of the protruding arm; a control loop circuit configured to track a signal relationship between an oscillation of the protruding arm detected by the protruding arm detection system and a drive signal provided to the actuation unit; and at least one control unit. The at least one control unit is configured to: drive the probe using a resonant drive signal provided by the control loop circuit when the tip is not in contact with the sample, using the excitation unit; reduce, by the positioning unit, a first distance between the tip and the sample along a z-direction during a first approach phase until at least one first stop condition of a first set of stop conditions is satisfied, wherein the first set of stop conditions includes detecting a shift in the frequency of the resonant drive signal used during the first approach phase; and terminate the first approach phase and disable the resonant drive signal when the at least one first stop condition of the first set of stop conditions is satisfied. Optionally, the control loop circuit includes: a frequency control system configured to provide a first output signal based on a phase of an oscillation detected by the outstretched arm and a phase set point; an amplitude control system configured to provide a second output signal based on an amplitude of the oscillation detected by the outstretched arm and an amplitude set point; and a multiplier configured to multiply the first output signal provided by the frequency control system by the second output signal provided by the amplitude control system, and provide the multiplied signal as a resonant drive signal to the excitation unit. Optionally, the frequency control system includes a phase detector for providing a phase signal, an integrator for providing a frequency control signal, and a controllable oscillator for providing an oscillator output signal. Optionally, the amplitude control system includes an amplitude detector for providing an amplitude signal and a PI controller for providing an amplitude feedback signal. According to another aspect, a computer-implemented method is provided for manipulating a sample using a nanomanipulator. The nanomanipulator includes a measuring tip for manipulating the sample and a positioning unit for moving the measuring tip. Furthermore, the sample is disposed on a sample support. An x-direction and a y-direction of the nanomanipulator are each arranged parallel to a main extension plane E of the sample and / or the sample support and perpendicular to each other. The method comprises the following steps: 1a) controlling the positioning unit to move the measuring tip along the y-direction so that a vertex of the measuring tip contacts a surface of the sample carrier or a test area of ​​the sample and the measuring tip leaves a first track on the surface; 1b) controlling the positioning unit to move the measuring tip along the x-direction so that the vertex of the measuring tip contacts the surface and the measuring tip leaves a second track on the surface; 1c) controlling an image recording device to record at least one image of the test area in each case, whereby the first track and the second track are at least partially captured therein; and 1d) determining an x-position of the vertex of the measuring tip with respect to the x-direction based on the first track captured in at least one image, and determining a y-position of the vertex of the measuring tip with respect to the y-direction based on the second track captured in the at least one image. Using this method, the x- and y-position of the actual apex of the measuring tip can be determined even if only the apparent apex of the measuring tip is visible in the captured and received image. In particular, the actual apex of the measuring tip may not be visible in the image because its line of sight with respect to the image recording device is obscured. In particular, the vertex of the measurement tip is the point and / or region of the measurement tip at which initial contact with the sample or a particle on the sample occurs when the measurement tip approaches the sample and / or particle. For example, the vertex of the measurement tip is the lowest point and / or region of the measurement tip with respect to the z-direction of the nanomanipulator. Specifically, the measurement tip of the nanomanipulator is configured to contact the surface of the sample at its vertex. Specifically, the z-direction of the nanomanipulator is configured perpendicular to the x-direction and the y-direction. Specifically, the z-direction of the nanomanipulator corresponds to the vertical direction of the nanomanipulator or its gravitational direction. In particular, the x-direction and y-direction of the nanomanipulator are any desired directions, which are each arranged parallel to a main extension plane of the sample and / or sample carrier (e.g. the surface of the sample carrier for sample arrangement) and perpendicular to each other. For example, the x-, y- and z-directions of the nanomanipulator may correspond to the x-, y- and z-directions of the positioning unit of the nanomanipulator. The sample is, for example, a lithography mask having a plurality of structures (e.g., absorber structures). The structure sizes of these structures range, for example, from 10 nm to 10 μm. These structures are arranged, for example, in a pattern used to generate a specific type of semiconductor wafer. The sample can be, for example, a transmissive lithography mask for deep ultraviolet (DUV) lithography (operating with wavelengths in the range of 30 to 250 nm) or a reflective lithography mask for extreme ultraviolet (EUV) lithography (operating with wavelengths in the range of 1 to 30 nm, particularly 13.5 nm). The sample may also be a microelectronic element such as, for example, an integrated circuit, in particular a central processing unit (CPU), a graphics processing unit (GPU), a random access memory (RAM), a flash memory, etc. The nanomanipulator and / or a superstructure containing the nanomanipulator comprises, for example, a sample stage device having a mounting base; a sample carrier for arranging the sample, the sample carrier being movably mounted on the mounting base; and an additional positioning unit for moving the sample carrier relative to the mounting base. The sample carrier can be moved, for example, in the x-direction and the y-direction (i.e., lateral direction) and / or the z-direction (vertical direction or direction of gravity) by means of the additional positioning unit. The sample carrier can also be rotatably mounted on the mounting base, for example, so that it can be rotated about the x-, y-, and / or z-direction by means of the additional positioning unit. The sample carrier particularly comprises a surface for arranging the sample. The measuring tip is, in particular, a tip which is configured for both measurement and manipulation (measuring and manipulator tip). The nanomanipulator comprises, for example, a projection arm on which a measuring tip is arranged and / or fixed. The projection arm and the measuring tip can also be of integral design. The term "projection arm" is used as in the German text. The measuring tip has, for example, a length in the range of 0.5 μm to 1 mm and a diameter in the range of 20 nm to 1 μm. In particular, the measuring tip can taper toward its free end. For example, the measuring tip can be composed of a material containing carbon, silicon, one or more precious metals, tungsten, platinum, iridium, and / or a platinum-iridium alloy. This allows for targeted movement to specific locations on the sample surface, particularly even if the sample has structures with a high aspect ratio. The aspect ratio can be defined, for example, as the ratio of the width to the height of the structure. An example of a structure with a high aspect ratio of 1:10 is a narrow, deep trench, for example, 1 μm wide and 10 μm deep. For example, when expressed as Mohs harness, the hardness of the measuring tip is 7 or more, 8 or more, and / or 9 or more. Mohs harness is based on the Mohs hardness scale developed by Friedrich Mohs. The nanomanipulator comprises a positioning unit on which a projection arm is movably mounted and which enables the projection arm to be moved relative to the positioning unit in three spatial directions x, y, and z (translational movement in three spatial directions). The three spatial directions preferably span three-dimensional space. The positioning unit is, for example, fixed to the housing of the nanomanipulator and / or to a superstructure containing the nanomanipulator. The extension arm, in particular, has an elongated longitudinal axis. Furthermore, the extension arm is movably fastened to a positioning unit at a first end relative to its longitudinal axis. This positioning unit allows the position of the first end of the extension arm (also referred to as the base point or base end of the extension arm) to be set in the three spatial directions x, y, and z. Furthermore, the extension arm has a measuring tip at its second (free) end relative to its longitudinal axis. If the measuring tip comes into proximity with the sample surface, an interaction occurs between the tip and the sample surface. This interaction can be based on direct contact, van der Waals interactions, further physical interactions, or a combination thereof. By moving the measuring tip over the sample surface (raster scanning), a three-dimensional image of the sample surface can be acquired. In this case, for example, the distance between the measuring tip and the sample surface is kept constant for each raster scan position via a closed-loop control circuit, and the position of the microactuator used to set the distance is recorded. Specifically, particles are foreign matter, such as dust or dirt, that settles on the surface of a sample. Particles can also be said to be adsorbed on the sample surface. Particles adsorbed on the sample surface can have varying compositions and shapes. For example, particle sizes range from 3 nm to 50 μm. Such particles can be located on the sample surface, for example, using optical analysis methods and approached in a targeted manner by a measuring tip. To pick up the particles with the measuring tip, they must be separated from the sample surface. This means that the forces acting between the sample surface and the particle must be overcome. The strength of the particle's binding to the sample surface depends on the particle's shape and composition, as well as the composition of the sample surface, particularly its surface energy. The higher the surface energy, the stronger the particle's adsorption. To pick up a particle with the measuring tip, the measuring tip is brought into contact with the particle. If the attractive force of the measuring tip is greater than the attractive force of the sample surface, the particle can be detached from the sample surface and can be picked up by the measuring tip. It can be helpful to first use the measuring tip to move the particle on the sample surface to break any existing bonds between the particle and the sample surface. This can, for example, reduce the binding energy associated with the particle's binding to the surface. Furthermore, for example, the contact area between the measuring tip and the particle can be increased. A larger contact area between the particle and the measuring tip increases the likelihood that the particle will adhere to the measuring tip and be detached from the sample surface. After the measuring tip has picked up the particles, they must be removed from the measuring tip again to be able to continue using the measuring tip. In this case, the particles should in particular be deposited at an undisturbed location on the sample surface or on a separate deposition unit. The nanomanipulator may be part of an upper apparatus for processing a sample, the apparatus including the nanomanipulator. The upper device for processing the sample may, for example, also include a control device for carrying out the proposed method. For example, the control device controls the positioning unit in step 1a) to move the measuring tip in the y-direction in order to write a first trajectory in the y-direction. For example, the control device controls the positioning unit in step 1b) to move the measuring tip in the x-direction in order to write a second trajectory in the x-direction. For example, the control device controls the image recording device in step 1c) to record at least one image of the test area in each case. For example, the control device receives the recorded images from the image recording device. For example, the control device thus determines the x-position and y-position of the vertex of the measuring tip in step 1d) based on the first and second trajectory captured in the images. Furthermore, the upper equipment for processing the sample may further include, for example, an image recording device, such as a scanning electron microscope and / or a scanning ion microscope, for recording images of the sample. In particular, the test area of ​​the sample carrier or sample (the material to which the first and second tracks are written) is an area of ​​the sample carrier or sample that is not affected by the tracks. For example, the test area of ​​the sample is an area that is not required when the sample is used (e.g., as a lithography mask). For example, a sample may include a substrate, a coating, and / or a structure (e.g., an absorber structure) made of a material having a first hardness. Furthermore, the sample support or the testing area of ​​the sample may include a material having a second hardness that is less than the first hardness. The first and second hardnesses each represent the mechanical resistance of the respective material to mechanical penetration by the apex of the measurement tip. For example, the first track and the second track are each a track written into the material of the test area by the apex of the measuring tip, such as an engraving track and / or a scratching track. For example, before applying the first track and the second track, the first track and the second track each have a recess relative to the surface of the test area. The first track is preferably arranged parallel to the y-direction, and the second track is preferably arranged parallel to the x-direction. Specifically, after step 1a), steps 1c) and 1d are initially performed only for the first trajectory. In this case, in step 1c), the image recording device is controlled to record at least one image of the test area, wherein at least a portion of the first trajectory is captured. After step 1b), steps 1c) and 1d are performed again only for the second trajectory. In this case, in step 1c), the image recording device is controlled to record at least one image of the test area, wherein at least a portion of the second trajectory is captured. For example, in a first configuration variant, the first track and the second track can be established on the surface of the test area so that they are spaced apart from each other and are arranged on the surface without contacting each other. In other words, the first and second tracks are discontinuous in this case. For example, in the second configuration variant, the first track and the second track can also be established on the surface of the test area such that the first track and the second track intersect (for example at a right angle). For example, in the third configuration variation, the first trajectory and the second trajectory (in addition to or instead of the two trajectories intersecting) may be portions of a continuous overall trajectory. Furthermore, in one, several and / or all of the three aforementioned configuration variants, between the generation of the first trajectory and the generation of the second trajectory, the vertex of the measuring tip can be removed from the surface of the test area, for example. For example, the image recording device is a scanning electron microscope and / or a scanning ion microscope. Furthermore, in this case, the x-position and y-position of the top point of the measuring tip are determined based on at least one scanning electron microscope image or scanning ion microscope image received from the scanning electron microscope or scanning ion microscope. According to one embodiment, the nanomanipulator includes a projection arm having a base end and a free end; the measurement tip is disposed on the free end of the projection arm; and the projection arm is movably fixed to the positioning unit at its base end. Furthermore, the positioning unit is controlled to move the base end of the projection arm, thereby moving the measurement tip. For example, the positioning unit is controlled by a control device. Specifically, the positioning unit is controlled to move the base end of the extension arm so that the measuring tip also moves. According to a further embodiment, the x-position and the y-position of the vertex of the measuring tip are determined by fitting a respective straight line, , to the first trajectory and the second trajectory captured in the image, . For example, the control device performs fitting of the respective straight lines, for example, by fitting the respective straight lines using a computer-aided approximation method, wherein the respective linear functions are fitted to the first trajectory captured in the image or the second trajectory captured in the image. According to another embodiment, the measuring tip is at least partially captured in the at least one image, wherein a lateral position of an apparent vertex of the measuring tip in the at least one image deviates from a lateral position of an actual vertex of the measuring tip in the at least one image, and the lateral position of the actual vertex of the measuring tip is determined relative to the lateral position of the apparent vertex of the measuring tip in the at least one image. By knowing the lateral position (i.e., x-position and y-position) of the actual vertex of the measuring tip relative to the lateral position (i.e., x-position and y-position) of the apparent vertex of the measuring tip in at least one image, an offset between the x- and y-position of the actual vertex of the measuring tip (not visible in the image) and the x- and y-position of the apparent vertex of the measuring tip (visible in the image) is determined. Since the x- and y-offsets generally do not change for a particular measuring tip, the x- and y-position of the actual vertex of the measuring tip can be easily determined using the x- and y-offsets determined based on any desired image of the measuring tip (in particular, those recorded along the same line of sight). Precisely knowing the x- and y-position of the actual top point of the measuring tip used to process the sample enables more accurate sample processing. For example, with the help of the measuring tip, particles on the sample can be removed in a more targeted and optimal manner. In particular, the image is a two-dimensional image. According to another embodiment, the lateral position of the actual apex of the measuring tip is determined relative to a lateral position of the base end of the extension arm. Thus, when the measuring tip is visible in the image, the point of contact between the actual apex of the measuring tip and the sample surface can be determined at any time. According to another aspect, a method for seating a tip or processing a sample includes: capturing a first image of a sample surface, the first image including at least one section not obscured by the tip; generating a second image including at least one section obscured by the tip and at least one marking disposed in the obscured section to indicate the location of at least one hidden element; and displaying the second image to an operator of a nanomanipulator on a user interface during manipulation of the sample. This method can be used alone or in combination with one or more of the other methods disclosed above or below. Optionally, the at least one marking comprises at least one of: a contact point indicator indicating the location of the contact point of the tip with the sample; a structure indicator indicating the edge or area of ​​a surface feature or particle located on the sample surface; and a tip indicator indicating the tip outline, wherein in the second image the tip is replaced by a corresponding segment of the sample surface obtained from the first image. According to another embodiment, the nanomanipulator comprises a deflection detection device for detecting a z-deflection of the free end of the extension arm along a z-direction, the z-direction being arranged perpendicular to the x-direction and the y-direction and pointing away from the sample. In addition, the method comprises the following steps: 6a) controlling the positioning unit to move the base end of the extension arm along the negative z-direction so that the z-distance between the base end of the extension arm and the sample with respect to the z-direction decreases and the measuring tip approaches the sample in a test area of ​​the sample; 6b) repeatedly receiving from the deflection detection device an extent of the z-deflection of the free end of the extension arm, which is dependent on a z-position of the base end of the extension arm from the sample; 6c) determining an approach curve comprising the extent of the z-deflection of the free end of the extension arm as a function of the z-position of the base end of the extension arm from the sample; 6d) receiving at least one image of the sample, the test area being at least partially captured therein; 6e) using the at least one received image as a basis for determining whether the sample is damaged in the test area; and 6f) if the sample is determined to be undamaged in the test area, storing a minimum z-deflection and / or a minimum z-distance of the approach curve as a safe minimum z-deflection of the free end of the extension arm or a safe z-distance of the base end of the extension arm from the sample. Thus, even though the exact z-position of the apex of the measuring tip is generally unknown, it is possible to determine a safe deflection of the free end of the extension arm and thus a minimum safe distance in the z-direction at which the apex of the measuring tip is spaced from the sample. In this case, the nanomanipulator is specifically used as a force sensor and performs force-distance spectroscopy. For example, the x-, y-, and z-positions of the base end of the extension arm are precisely known from the positioning unit. Specifically, the x-, y-, and z-positions of the base end of the extension arm can be set by controlling the positioning unit. Thus, for example, the positioning unit can provide the current values ​​of the x-, y-, and z-positions of the base end of the extension arm relative to the positioning unit. In particular, the z-position of the base end of the extension arm can thus be provided by the positioning unit and is therefore precisely known. However, due to the deflection of the free end of the extension arm and any bending of the measuring tip relative to the extension arm, the exact z-position of the apex of the measuring tip may be unknown. The deflection of the free end of the extension arm in the z-direction is caused by the force acting between the measurement tip and the sample. Furthermore, the deflection of the free end of the extension arm in the z-direction is proportional to the spring constant of the extension arm. Specifically, the extension arm bends to varying degrees during sample scanning, depending on the force acting between the measurement tip and the sample. A deflection detection device can be used to detect the degree of bending or deflection of the free end of the extension arm in the z-direction. The nanomanipulator and / or a superstructure device containing the nanomanipulator includes such a deflection detection device. For example, the deflection detection device is a light pointing device. The light pointing device includes, for example, a laser light source and a position-sensitive light sensor. The laser beam emitted by the laser light source is directed to the free end of the extension arm and reflected from it at the undeflected position of the extension arm to the center of the position-sensitive light sensor. The light sensor is subdivided into four areas, for example, "upper left," "upper right," "lower left," and "lower right." If the bending (deflection) of the extension arm changes, then the reflected laser spot on the light sensor moves, just like in the case of the light pointer. By measuring the intensity of the four areas of the light sensor, vertical and horizontal bending signals can be determined, which are proportional to the normal force and lateral force, respectively. Furthermore, due to the interaction between the measuring tip and the sample, bending (i.e., elastic deformation) of the measuring tip relative to the extension arm may occur (e.g., due to lateral movement of the measuring tip during contact between the measuring tip and the sample). The degree of bending of the measuring tip relative to the extension arm can be determined by image processing of recorded images of the measuring tip (e.g., scanning electron microscope images, scanning ion microscope images). For example, in step 6a) the x- and y-positions of the base end of the extension arm are kept constant. In particular, the test area of ​​the sample is an area that is not affected by damage to the sample. For example, the test area of ​​the sample is an area that is not required when the sample is used (eg, as a mask in lithography). For example, damage to the test area includes recessed material in the test area. For example, the safety deflection system is stored in a storage device of the nanomanipulator. For example, before controlling the positioning unit to move the measuring tip along the negative z-direction, the method includes: controlling the positioning unit to move the measuring tip laterally (i.e., along the x- and / or y-direction) into a test area of ​​the sample, wherein during the subsequent control of the positioning unit to move the measuring tip along the negative z-direction, the x-position and y-position of the base end of the extension arm remain constant. For example, after determining the approach curve, the method comprises controlling the positioning unit to move the measuring tip by a predetermined z-distance in the positive z-direction (withdrawing the measuring tip by a predetermined z-distance from the sample). For example, steps 6a) to 6f) are performed by a control device. In several embodiments, in step 6a), the positioning unit is controlled to move the base end of the extension arm in the negative z-direction so that the measuring tip in the test area of ​​the sample approaches the sample to a final z-distance relative to the z-direction. Furthermore, a plurality of approach curves are determined based on the different final z-distances of the measuring tip from the sample relative to the z-direction and the x- and / or y-positions of the measuring tips offset from one another. Furthermore, at least one image of the sample is received, assigned to each determined approach curve, wherein the test area is at least partially captured. For each received image, it is then determined whether the sample in the test area is damaged. Furthermore, the minimum deflection (and therefore the minimum distance) of the approach curve based on the minimum final z-distance of the measuring tip from the sample is stored as a safety deflection of the free end of the extension arm, for which the sample in the test area is not damaged, as determined based on the corresponding image. According to a further embodiment: a plurality of approach curves are determined based on a plurality of different test areas in each case, which test areas differ from one another on account of the material type of the respective test areas; at least one image is received, in which the plurality of test areas are at least partially captured; for each approach curve determined, it is determined based on the at least one received image whether the sample is damaged in the respective test area; and the minimum z-deflection and / or the minimum z-distance of the respective approach curve is stored as a safe z-deflection of the free end of the extension arm or as a safe z-distance of the base end of the extension arm from the sample (if the sample is determined to be undamaged in the respective test area) in a manner depending on the corresponding material of the respective test area. For example, at least one image is received in which the respective test area is at least partially captured, in such a manner that it is assigned to each determined approach curve. Alternatively, two, more or all test areas are imaged in the image details of the image. In view of the type of materials in the test regions, different test regions may, for example, include materials corresponding to the material of the sample structure (e.g., absorber structure), materials corresponding to the sample substrate, and a coating layer, cover layer, and / or protective layer corresponding to the sample (e.g., a coating layer of an EUV mask). According to another embodiment, the nanomanipulator preferably includes a sample stage device having a mounting base, a sample stage movably arranged on the mounting base, and a further positioning unit for moving the sample stage relative to the mounting base. Furthermore, the method comprises: 8a) controlling the positioning unit to move the measurement tip in the negative z-direction z so that the measurement tip contacts the sample 402; and 8b) controlling the positioning unit and / or the further positioning unit to move the measurement tip and / or the sample arranged on the sample stage so that the measurement tip and the sample are at a predetermined distance from each other. Thus, starting from contact between the measuring tip and the sample (e.g., the surface of the sample), the measuring tip can be moved away from the sample by a predetermined distance. Thus, it can be advantageous to apply a predetermined, fixed working distance between the measuring tip and the sample (i.e., in the z-direction). The fixed, predetermined working distance improves the reproducibility of image recordings of the sample (e.g., performed using a scanning electron microscope and / or a scanning ion microscope), in which the measuring tip is at least partially captured. This can improve image monitoring processes. For example, image monitoring processes involve manipulation processes (e.g., displacement of particles on the sample and / or removal of particles from the sample) and / or particle beam-induced processes (e.g., electron beam-induced processes and / or ion beam-induced processes), such as etching processes and deposition processes, that utilize the measuring tip. Furthermore, the predetermined distance can be selected so that drifting movement of the measuring tip relative to the sample does not cause damage to the sample, such as damage to the sample structure. Drifting movement of the measuring tip relative to the sample can occur due to thermal drift (e.g., heating of the measuring tip and / or extension arm) or due to charging of the sample surface caused by particle beam processing (e.g., imaging with a scanning electron microscope). This increases the forces between the measuring tip and the sample, leading to drifting movement. So-called "subsequent creeping" is also known when the measuring tip moves to a specific position on the sample. In a first variation, a predetermined distance between the measurement tip and the sample is set by controlling a positioning unit to move the base end of the extension arm, thereby causing the measurement tip to move away from the sample. Alternatively, in a second variation, a predetermined distance between the measurement tip and the sample is set by controlling another positioning unit of the sample carrier device to move the sample carrier, thereby causing the sample to be positioned on the sample carrier in the negative z-direction away from the measurement tip. For example, steps 8a) and 8b) are performed by a control device. In various embodiments, the nanomanipulator includes a deflection detection device (e.g., a light pointer device) for detecting deflection of the free end of the extension arm in the z-direction. The deflection detection device is disposed perpendicular to the x- and y-directions. Furthermore, in step 8a), the deflection detection device receives the degree of deflection of the free end of the extension arm in the z-direction. Furthermore, in step 8a), the positioning unit controls the base end of the extension arm to move in the negative z-direction, causing the measuring tip to approach the sample, until the received degree of deflection corresponds to a predetermined degree of deflection. Specifically, the predetermined degree of deflection corresponds to contact between the measuring tip and the sample (e.g., the surface of the sample). According to another embodiment, the method further includes: 9a) providing a removal trajectory for removing a particle arranged on the sample, wherein the removal trajectory T is located in an xy-plane spanning the x-direction and the y-direction and the removal trajectory intersects an x-position and a y-position of the particle; 9b) controlling the positioning unit to position the measuring tip at a first predetermined z-distance from the sample with respect to the z-direction; 9c) controlling the positioning unit to move the measuring tip laterally along the determined removal trajectory and at the first predetermined z-distance from the sample; and 9d) controlling the positioning unit to move the measuring tip away from the sample in the positive z-direction; 9e) determining whether the particle is adhered to the measuring tip; and 9f) repeating steps 9b) to 9e) for one or more additional predetermined z-distances that are gradually smaller than the first predetermined z-distance until it is determined that the particle is adhered to the measuring tip, wherein steps 9b) to 9f) are performed fully automatically. Removing particles from a sample requires, in particular, nanoscale manipulations. The proposed particle removal process enables fully automated removal of particles from a sample, i.e. without requiring any user intervention. In particular, a predetermined removal trajectory is applied, which is a path and / or trajectory along which the measuring tip moves to come into contact with the particles. The removal trajectory can also be said to be the entry path of the measuring tip for coming into contact with the particles. In particular, the predetermined removal trajectory (which is particularly arranged in the xy-plane) can be performed continuously in a fully automated manner at different z-distances from the sample to the measuring tip. In this case, the z-distance between the measuring tip and the sample is gradually and incrementally reduced. This allows the measuring tip to come into contact with the particles as far as possible (i.e. as close to the sample surface as possible) without damaging the measuring tip and / or the sample. In particular, the gradual reduction of the z-distance between the measuring tip and the sample is advantageous because physical contact between the measuring tip and / or the sample is prevented to the greatest extent possible, thereby avoiding damage to the measuring tip and / or the sample. For example, a user simply initiates the particle removal process, for example, via a human-machine interface (HMI). Examples of such interfaces include a keyboard, mouse pointer, joystick, game controller, touchscreen, and the like. Steps 9b) to 9f) are then fully automated by initiating the particle removal process. Specifically, initiating the particle removal process automatically moves the measurement tip at different z-distances, initially laterally along the removal trajectory (step 9c) and then away from the sample in the positive z-direction (step 9d) until a particle adheres to the measurement tip. For example, the first predetermined z-distance is 50 nm, 40 nm, or 30 nm. For example, one or more additional predetermined z-distances are 5 nm, 10 nm, or 15 nm smaller than the immediately preceding z-distance (i.e., the first or additional predetermined z-distance). Purely by way of example, the first predetermined z-distance is 50 nm, the second predetermined z-distance is 40 nm, the third predetermined z-distance is 30 nm, the fourth predetermined z-distance is 20 nm, and the fifth predetermined z-distance is 10 nm. If it has been determined in step 9e) that the particle is adhered to the measuring tip at the first z-distance, step 9f) is not carried out. The lateral movement of the measuring tip is in particular a movement of the measuring tip in the x- and / or y-direction (in other words in the xy-plane). For example, the measuring tip moves only in the x-direction, only in the y-direction or simultaneously in the x- and y-directions. Therefore, the x-position and y-position of a particle are relative to its position in the x-direction and y-direction. For example, the removal trajectory is a linear removal trajectory. For example, steps 9a) to 9f) are performed by a control device. In various embodiments, determining a removal trajectory includes: receiving an image of at least a portion of the sample, wherein particles disposed on a surface of the sample are captured in the image; and determining a removal trajectory for removing the particles based on the received image. In various embodiments, a linear removal trajectory is determined to remove the particle, wherein the removal trajectory intersects the particle, the length of the removal trajectory is greater than a size of the particle, and the removal trajectory does not include structure of the sample. In various embodiments, a linear particle removal trajectory for removing a particle can be determined where, on one side of the particle, the removal trajectory protrudes beyond the particle by 2 times the particle size. Additionally or alternatively, for example, a removal trajectory can be determined where, on the other side of the particle, the removal trajectory protrudes beyond the particle by 0.5 times the diameter of the measuring tip. In various embodiments, the method includes automatically monitoring one or more parameters, such as a deflection of the free end of the extension arm in the z-direction, a twisting of the free end of the extension arm about the x-direction, and / or a bending of the measuring tip relative to the extension arm. Furthermore, if it is determined that the current state of one or more parameters is outside a permitted range, the positioning unit is controlled to stop the lateral movement of the measuring tip and / or to retract the measuring tip relative to the sample (i.e., in the positive z-direction). For example, in step 9b), the positioning unit is controlled in such a way that the measuring tip (ie the vertex of the measuring tip) is positioned at a point on the removal trajectory with respect to the x- and y-direction. According to a further embodiment, the step 9c) comprises controlling the positioning unit to move the measuring tip laterally along the determined removal trajectory in steps a first predetermined lateral distance, and preferably in steps one or more further predetermined lateral distances which are progressively larger than the first predetermined lateral distance. Because the measurement tip is moved laterally in incremental increments, gradually increasing forces can be applied laterally to attempt to break free particles apart. However, due to the risk of damaging both the sample and / or the measurement tip, the lateral distance is only increased gradually. This ensures that only the force required to separate the particles is applied. For example, the first predetermined lateral distance is 10 nm, 20 nm or 30 nm. For example, the one or more further predetermined lateral distances are 30 nm, 40 nm, 50 nm, 60 nm and / or 70 nm. According to another embodiment, the method comprises: 9a') controlling the positioning unit to position the measuring tip on the sample surface adjacent to the particle on the surface, wherein the base point of the extending arm is located at a first predetermined z-distance from the sample with respect to the z-direction; 9b') controlling the positioning unit to move the measuring tip laterally to separate the particle from the surface; 9c') determining whether the particle has moved on the surface; and 9d') repeating steps 9a') to 9c') for one or more additional predetermined z-distances, wherein the one or more additional predetermined z-distances are located between the base point of the extending arm and the sample and are gradually smaller than the first predetermined z-distance until it is determined that the particle has moved on the surface, wherein steps 9a') to 9d') are performed fully automatically. By repeating steps 9a') to 9c') with progressively smaller z-distances between the base point of the extended arm and the sample, gradually increasing force is applied to the measuring tip, and thus to the particle, until the particle detaches from the surface. Therefore, only the force required to detach the particle from the surface is applied. At the same time, unnecessary high forces are avoided, thereby preventing damage to the measuring tip and / or sample. According to a further embodiment, the method comprises: 12a) controlling the positioning unit to move the measuring tip laterally in the direction of a particle arranged on the sample; 12b) determining whether the particle is adhered to the measuring tip; 12c) if the particle is determined to be adhered to the measuring tip, controlling the positioning unit to move the measuring tip away from the sample in the positive z-direction and / or move the measuring tip along a curved trajectory, which curves from an initial lateral movement to a movement in the positive z-direction in the area of ​​the particle, wherein steps 12a) to 12c) are performed fully automatically. Thus, the movement and lifting of the measurement tip, which may be required to pick up particles from the sample surface, can be fully automated. In particular, it can be fully automatically determined whether a particle is adhering to the measurement tip. Furthermore, if adhering to the measurement tip is confirmed, the measurement tip is moved away from the sample in the positive z-direction (step 12c), thereby lifting the particle from the sample surface; this is performed fully automatically. For example, steps 12a) and 12b) are repeated simultaneously and / or repeatedly. For example, steps 12a) to 12c) are performed by a control device. In step 12a), the control positioning unit is controlled, in particular, to move the measuring tip linearly laterally along the direction of the particles arranged on the sample and / or to move the measuring tip along a curved trajectory. According to a further embodiment, the method comprises: controlling the positioning unit to move the measuring tip in a lateral direction and / or in a positive z-direction to pick up a particle disposed on the sample using the measuring tip; determining whether the particle is adhered to the measuring tip based on: a degree of deflection of the extension arm in a lateral direction received from a deflection detection device; a plurality of received images of at least a portion of the sample, capturing the images of the particle and brightness changes of the particle, and / or contrast changes of the particle relative to the measuring tip in the plurality of images as determined by image processing; a plurality of images of at least a portion of the sample, the images captured of the particle received from an image recording device, and a migration of the particle from a fixed set focus of the image recording device as determined through image processing of the plurality of images; and / or information received from the image recording device, the image recording device recording an image of at least a portion of the sample with an autofocus setting focused on the particle, wherein the particle was captured, and the information regarding the extent of automatic adjustment of the autofocus focused on the particle, the adjustment being greater than a predetermined threshold. Thus, it is determined according to one, several or all of the four different variants (first to fourth) whether a particle adheres to the measuring tip. In particular, it is thus possible to determine in each case, for example fully automatically, whether a particle adheres to the measuring tip. For example, a particle can be moved laterally through the measuring tip until adhesion is determined according to one or more of the first to fourth variants. The measuring tip can then be moved (i.e., lifted) in the positive z-direction, using one or more of the first to fourth variants to check whether the particle is lifted along with the measuring tip (i.e., remains adhered to the measuring tip) or not lifted along with the measuring tip (i.e., has detached from the measuring tip again). For example, the control device receives the degree of deflection detected by the deflection detection device. For example, the control device receives one or more images recorded by the image recording device. For example, the control device determines whether the particle adheres to the measurement tip based on one, more, or all of the four different variations. In a first variation, whether a particle is attached to the measuring tip is determined based on the extent of lateral deflection of the extension arm, which is received from a deflection detection device. The extent of lateral deflection of the extension arm can be determined, for example, based on the degree of twisting of the extension arm. For example, if the extent of lateral deflection of the extension arm is greater than a predetermined threshold, then the measuring tip is determined to be in contact with the particle. In a second embodiment, whether a particle is attached to the measuring tip is determined based on a change in the particle's brightness and / or a change in the particle's contrast in an image of the particle (e.g., an electron microscope image and / or an ion microscope image). For example, in addition to the particle, at least a portion of the measuring tip is captured in a plurality of received images of the sample. For example, a change in particle brightness is a change in the brightness of the particle in the image relative to the brightness of the measuring tip. For example, a change in particle contrast is a change in the contrast between the particle and the measuring tip in the image. For example, when the particle is attached to the measuring tip, the particle's brightness increases compared to when the particle is not attached to the measuring tip. For example, the adhesion of particles to the measuring tip causes the particles to become charged, which makes them appear brighter in the image. For example, the detachment of particles from the measuring tip causes them to appear darker again in the image. In a third variant, the determination that the particle adheres to the measuring tip and is therefore lifted along with the measuring tip (movement in the positive z-direction) is based on the particle's migration from a fixed, set focal point of the image recording device. Specifically, based on the image, it is determined that the particle is initially in focus of the image recording device (i.e., the focus is adjusted to the particle) and that in subsequent images, the particle is no longer in focus of the image recording device. In a fourth variant, an image of the particle is recorded using an autofocus setting focused on the particle. Furthermore, after automatically adjusting beyond a predetermined threshold for autofocus focused on the particle, the particle's z-position changes significantly, indicating that the particle is lifted along with the measurement tip (in the positive z-direction). In a fourth variant, it can be optionally determined whether the particle-adjusted autofocus is to be changed as a function of a movement of the measuring tip in the positive z-direction. For example, this movement of the measuring tip in the positive z-direction is determined using positional information about the base end of the extension arm, which is received by the positioning unit. According to another embodiment, the nanomanipulator comprises a sample carrier having a mount, a sample carrier arranged on the mount for transverse movement, and a further positioning unit for laterally moving the sample carrier relative to the mount in the x-direction and the y-direction. Furthermore, the method comprises: 14a) controlling the positioning unit to position the measurement tip at a lateral initial position with respect to the x-direction and the y-direction, the lateral initial position being preset in the positioning unit; 14b) receiving at least one image of the sample, wherein a particle arranged on the sample is captured; 14c) determining a lateral position of the particle captured in the at least one image based on image processing; and 14d) controlling the further positioning unit to laterally move the sample carrier with the sample, wherein the lateral position of the particle corresponds to the lateral initial position of the measurement tip with respect to the x-direction and the y-direction; and performing steps 14a) to 14d) fully automatically. The measuring tip can thus be brought into its pre-defined home position. Furthermore, the particle to be processed can be positioned below the measuring tip, i.e., at the same x- and y-position as the measuring tip. This facilitates particle processing using the measuring tip. For example, the measuring tip has only a small, limited lateral range (e.g., ±20 μm in the x- and y-directions) within which it can move. Therefore, it is advantageous to fully automatically position the particle below the measuring tip at the same x- and y-coordinates as the measuring tip, while also positioning the measuring tip at the origin. This leaves ample space around the particle in the x- and y-directions for movement of the measuring tip, allowing it to pick up the particle. Automatically moving the sample carrier is particularly advantageous if several particles positioned on the sample are too far apart to be reached by the measuring tip simply by moving it. Therefore, fully automatic positioning of the particle below the measuring tip at the same x- and y-coordinates as the measuring tip and simultaneously positioning the measuring tip at its origin is also advantageous, since this results in the particle being in the field of view of the image recording device. The initial position of the measuring tip with respect to the x- and y-directions preset in the positioning unit is, for example, the origin position of the measuring tip, which is preset in the positioning unit. The initial position or origin position corresponds, for example, to the origin of the coordinate system of the positioning unit (x=0, y=0). For example, steps 14a) to 14d) are performed by a control device. In several embodiments, the method includes: controlling an image recording device to record one or more first images of at least a portion of the sample, in which the measuring tip is at least partially captured; determining the position (lateral position, x-position and / or y-position, for example the position of the apparent vertex of the measuring tip) of the measuring tip in the one or more first images based on image processing; and controlling the image recording device to record one or more further images of at least a portion of the sample, in which the measuring tip captured in the (multiple) first images is arranged at a predetermined position in the image (for example, at the center of the image). Thus, during repeated recording of images, the measuring tip can automatically remain in a predetermined position (eg in the image center) in one or more further images (referred to as: tip tracking). For example, the lateral position (ie the x-position and / or the y-position) of the measuring tip is determined based on image processing of the first image or the first images. For example, the position (e.g., lateral position or x-position and / or y-position) of the apparent apex of the measuring tip is determined based on image processing of the first image or images. Furthermore, for example, the image recording device is controlled to record one or more further images of at least a portion of the sample. The apex of the measuring tip captured in the first image(s) is located at a predetermined position in the image (e.g., at the center of the image). According to another aspect, a computer-implemented method for manipulating a sample using a nanomanipulator is provided. The nanomanipulator comprises a measuring tip for manipulating the sample and a positioning unit for moving the measuring tip. Furthermore, the sample is disposed on a sample support. The x-direction and y-direction of the nanomanipulator are each arranged parallel to a main extension plane of the sample and / or the sample support and perpendicular to each other. The surface of the sample has nanostructures, which are used to determine the actual vertex of the measuring tip. The method comprises the following steps: 15a) controlling the positioning unit to move the measuring tip laterally from a lateral initial coordinate to a lateral end coordinate to scan the nanostructure and generate raster scan data; 15b) determining the nanostructure coordinates of the highest point of the nanostructure in the raster scan data; 15c) determining a first lateral distance between the nanostructure coordinates and the lateral end coordinates; 15d) recording at least one image of the sample in which the measuring tip and the nanostructure are at least partially captured, wherein the measuring tip is located at the lateral end coordinate; 15e) determining a second distance between the measuring tip and an apparent vertex of the nanostructure; and 15f) determining the position of the actual vertex of the measuring tip based on the difference between the first distance and the second distance. Thus, the position (e.g., x-position and y-position) of the actual apex of the measuring tip can be determined even if only the apparent apex of the measuring tip is visible in the recorded and received image. In particular, the actual apex of the measuring tip may not be visible in the image because it is hidden from the view of the image recording device. The lateral dimensions of the nanostructure used to determine the actual apex of the measuring tip are, for example, 30 nm or less, 20 nm or less, 10 nm or less and / or 5 nm or less. The nanostructure used to determine the actual apex of the measuring tip can, for example, have a spherical, hemispherical and / or spherical surface. Alternatively, the nanostructure used to determine the actual apex of the measuring tip can also, for example, have a pointed tip, in particular a tip that tapers away from the sample surface. According to another aspect, a computer program product is proposed, comprising a plurality of instructions, which, when executed by at least one computer, cause the computer to perform the above-described method. A computer program product, such as a computer program tool, may be provided or supplied, for example, as a storage medium, such as a memory card, USB memory stick, CD-ROM, DVD, or in the form of a file that can be downloaded from a server in a network and / or from a cloud-based source. For example, in a wireless communication network, this can be implemented by transmitting an appropriate file using the computer program product or computer program tool. According to another aspect, a device for processing a sample is proposed, comprising: a nanomanipulator having a measuring tip for processing the sample and a positioning unit-sample carrier for moving the measuring tip, for configuring the sample, wherein an x-direction and a y-direction of the nanomanipulator are each configured to be parallel to a main extension plane of the sample and / or the sample carrier and perpendicular to each other; and a control device configured to perform the method described above. The main extension plane of the sample and / or the sample carrier is, for example, an xy-plane spanned by the x-direction and the y-direction. The device for processing samples comprises, for example, a sample carrier device having a mounting base, wherein the sample carrier can be movably arranged on the mounting base. Furthermore, the sample carrier device comprises, for example, an additional positioning unit for moving the sample carrier relative to the mounting base. The sample carrier can be moved, for example, in the x-direction and the y-direction (i.e., transversely) and / or the z-direction (vertically) using the additional positioning unit. The sample carrier can also be rotatably mounted on the mounting base, such that it can be rotated about the x-, y-, and / or z-direction using the additional positioning unit. The sample carrier particularly comprises a surface for arranging the sample. A relative unit (e.g., a control device) can be implemented using hardware and / or software. In the case of hardware implementation, the relative unit can be implemented as a device or a portion of a device, such as a computer or microprocessor. In the case of software implementation, the relative unit can be implemented as a computer program product, a function, a routine, a portion of program code, or an executable object. In this case, the term "a" or "an" should not necessarily be construed as limiting to only one element. Rather, a plurality of elements may be provided, such as, for example, two, three, or more. Any other numerical values ​​used herein should not be construed as limiting to the exact number of elements recited. Instead, upward and downward numerical deviations are possible unless otherwise indicated. The numbering of features in claims such as 1a, 1b, 6a, 6b, etc., whether in a single claim or in a combination of multiple claims, does not imply any order. For example, step 6b may be performed before step 6a, unless otherwise indicated. Furthermore, the terms "first," "second," etc., are used solely to distinguish distinct elements from one another. For example, the use of a "third" (or any other) element in a claim does not necessarily require the presence of a "first" or "second" (or any other) element therein. Furthermore, a "second" or "third" (or any other) element may be renamed a "first" (or any other) element. The embodiments and features described for one or more method aspects are also applicable to the proposed apparatus aspects, and vice versa. In addition, the aforementioned method aspects and / or the aforementioned apparatus aspects can be combined with each other. Further possible implementations of the present invention also include combinations not explicitly mentioned of features or embodiments described above or below with respect to the exemplary embodiments. In this case, those skilled in the art will also add individual aspects as improvements or supplements to the corresponding basic forms of the present invention. Further advantageous configurations and aspects of the present invention are the subject of the following claims and the exemplary embodiments of the present invention described below. The present invention will be explained in more detail below based on preferred embodiments with reference to the accompanying drawings. Unless otherwise indicated, identical or functionally identical elements have the same reference numerals in the drawings. Furthermore, it should be noted that the illustrations in the drawings are not necessarily drawn to scale. FIG1 schematically illustrates an exemplary embodiment of an apparatus 100 for analyzing and / or processing a sample 102 using an atomic force microscope 104 as an example of a nanomanipulator. Atomic force microscope 104 includes a measuring tip 106 for analyzing and / or processing sample 102. Measuring tip 106 is disposed on an extension arm 108, which is movably secured to a positioning unit 110 (movement unit). Specifically, extension arm 108 includes a first end 112 (base end 112), at which extension arm 108 is movably secured to positioning unit 110. Furthermore, extension arm 108 includes a second end 114 (free end 114), at which measuring tip 106 is disposed. Positioning unit 110 enables measurement tip 106 to be moved in three spatial directions (x, y, and z) (translational movement in the x, y, and z directions). Movement in the x and / or y directions is referred to herein as lateral movement. Herein, the movement in the z-direction is referred to as the approach of the measuring tip 106 to the sample 102 (negative z-direction) and the removal / away movement of the measuring tip 106 from the sample 102 (positive z-direction). The apparatus 100 includes a housing 116, wherein the residual gas pressure can be evacuated to 10 -5 -10 -9 mbar. The atomic force microscope 104 is arranged in a housing 116. Furthermore, a sample carrier 120 is provided for clamping the sample 102. The sample carrier 120 is preferably held by the housing 116 via a mounting base 122. The sample carrier 120 may further include an additional positioning unit 124 (not shown separately), via which the sample carrier 120 can be displaced relative to the mounting base 122 in, for example, three spatial directions x, y and z and can be rotated, for example, about at least one axis (for example, an axis arranged parallel to the z-direction in FIG. 1 ). Reference numeral 126 denotes a sample carrier device, which includes the sample carrier 120, the mounting base 122 and the additional positioning unit 124. Furthermore, for example, a particle beam column (PBC) 128 is disposed in the housing 116. The PBC 128 is configured to provide a particle beam 130. The PBC 128 can be specifically designed as a particle beam microscope and can be used to monitor the processing of the sample 102 using the measurement tip 106. For example, the particle beam column 128 is an electron column 128 configured to provide an electron beam 130. In particular, the electron column 128 can be designed as an electron microscope. For example, the particle beam column 128 is described below as an electron column 128. However, in other examples, the particle beam column 128 may also be an ion column (not shown) configured to provide an ion beam. In combination with the process gas supply unit 134 , the electron column 128 can additionally be used to perform a particle beam induced treatment process on the sample 102 . For this purpose, for example, a process gas 136 is supplied via the process gas supply unit 134 and irradiated by the particle beam 130 . The measuring tip 106 can be used to pick up particles 132 ( FIG. 3 ) adhering to the sample surface 138 ( FIG. 2 ) of the sample 102 . For this purpose, the measuring tip 106 is moved, for example, via the positioning unit 110 . The sample carrier 120 can also be moved with its additional positioning unit 124 . In particular, the picking up of the particles 132 by the measuring tip 106 is monitored in real time using an electron microscope 128 . Subsequently, the measuring tip 106 is moved to a storage unit (not shown) via the positioning unit 110 , wherein the particles 132 are transferred from the measuring tip 106 to the storage unit. FIG1 additionally illustrates a control device 140 for controlling the atomic force microscope 104 (e.g., positioning unit 110), the sample carrier 120 or another positioning unit 124, the electron microscope 128, and / or the process gas supply unit 134. A human-machine interface 142 may be provided as part of the control device 140 or connected to the control device 140 via a wired or wireless connection for data transmission. The human-machine interface 142 may include, for example, a display device 144, a speaker (not shown), a keyboard 146, a mouse pointer 148, a joystick, or a game controller (not shown). As shown in FIG2 , the atomic force microscope 104 may, for example, include a deflection detection device 150 (e.g., a light pointer device 150 ) for detecting a degree of deflection D of the free end 114 of the extension arm 108 along the z-direction. Specifically, the z-direction is arranged perpendicular to the sample 102 or the main extension plane E of the sample 102 and / or the sample support platform 120 (the xy-plane in FIG3 ). The deflection D of the free end 114 of the extension arm 108 along the z-direction is caused by the force acting between the measuring tip 106 and the sample 102 and is proportional to the spring constant of the extension arm 108. Therefore, the force acting on the extension arm 108 along the z-direction can be determined by detecting the deflection D. The light pointer device 150 can also be used to detect the degree of rotation R of the free end 114 of the extension arm 108 about the x-direction. Lateral forces acting between the measurement tip 106 and the sample 102 can cause the free end 114 of the extension arm 108 to rotate R about the x-direction (torsion R; see FIG2 ). The light pointer device 150 includes, for example, a laser light source 152 and a position-sensitive photodetector 154. A laser beam 156 emitted by the laser light source 152 is directed toward the free end 114 of the extension arm 108 and reflected from it onto the position-sensitive photodetector 154. The position-sensitive photodetector 154 includes, for example, four photosensitive regions ul, ur, bl, and br. In the undeflected position of the extension arm 108, the laser beams 156 and 158 are reflected onto the center of the photodetector 154, as shown in FIG2 . However, if the extension arm 108 is deflected in the positive or negative z-direction (deflection D), the reflected laser beam 158 shifts on the position-sensitive photodetector 154, as in the case of a light pointer. By measuring the received intensity in the four regions ul, ur, bl, and br of the position-sensitive photodetector 154, the vertical and horizontal deflection signals (bending signals) of the extension arm 108 can be determined. The deflection signal is proportional to the force acting on the extension arm 108 in the z-direction (normal force) and is also proportional to the lateral force acting in the x-direction or the y-direction. For example, the bend B ( FIG. 2 ) of the measuring tip 106 relative to the extension arm 108 can also be determined using this method. Specifically, the interaction between the measuring tip 106 and the sample 102 can cause the measuring tip 106 to bend B (i.e., elastic deformation) relative to the extension arm 108. For example, the measuring tip 106 can bend due to lateral movement (in the x-direction and / or y-direction in FIG. 2 ) of the measuring tip 106 while the measuring tip 106 is in contact with the sample 102. The extent of the bend B of the measuring tip 106 is determined by image processing of the recorded image 160 of the measuring tip 106. The apparatus 100 ( FIGS. 1 and 2 ) shown includes a number of optional components, the presence of which is not essential. Specifically, these include a housing 116 , a vacuum pump 118 , a sample support assembly 126 , an electron column 128 (or ion column), a process gas supply unit 134 , a human-machine interface 142 , and a deflection detection device 150 . FIG3 shows an image 160 (e.g., a scanning electron microscope image 160, or SEM image 160) of a portion of an exemplary sample 102. FIG4 shows a cross-sectional view of the portion of sample 102 shown in image 160 in FIG3, taken along line IV-IV in FIG3. Sample 102 includes, for example, a structure 162 (e.g., absorber structure 152) having a central groove 164. H represents the height of structure 162. Furthermore, an exemplary particle 132 is shown on sample 102, located in one of the grooves 164 at the edge of one of the absorber structures 162 and requiring removal. Reference numeral 166 in FIG3 and FIG4 denotes the substrate of sample 102. Removing the particle 132 using the atomic force microscope 104 requires manipulating the measuring tip 106 with nanometer-scale precision. This may require the user to control the measuring tip 106 to move to the particle 132 multiple times and track the process in the SEM image 160 until the particle 132 finally adheres to the measuring tip 106 and can be removed from the sample 102. Furthermore, processing the sample 102 (particularly removing the particle 132 from the sample 102) is further complicated by the fact that the precise location of the apex 168 (FIG. 2) of the measurement tip 106 is often unknown. Specifically, the apex 168 of the measurement tip 106 is the point and / or area of ​​the measurement tip 106 where the measurement tip 106 makes initial contact with the sample 102 or a particle 132 on the sample 102 as the measurement tip 106 approaches the sample 102 and / or the particle 132. Due to the geometry of the measurement tip 106, the actual apex 168 of the measurement tip 106 may not be visible in the SEM image 160, and therefore the precise x and y positions of the actual apex 168 cannot be determined from the SEM image 160 alone. 1, y 1 (Figure 5). FIG5 illustrates a measuring tip 106 having a geometry with a configured vertex 168, wherein the vertex 168 is obscured with respect to the line of sight S of the scanning electron microscope 128. Therefore, the actual vertex 168 will not be visible in the SEM image 260 ( FIG6 ). Instead, the point 170 ( FIG5 ) of the measuring tip 106 will appear as the apparent vertex 170 in the SEM image 260. In the example of FIG6 , the actual vertex 168 is located at a lateral position x 1, y 1, and the apparent vertex 170 is located at the lateral position x 2, y 2. In the example of Figure 6, the y-position y of the actual vertex 1 corresponds to the y-position y of the apparent vertex 170 2. However, the actual x-position x of vertex 168 1 From the x-position x of the apparent vertex 170 2Displacement distance Δx. A computer-implemented method for processing a sample 102 using an atomic force microscope 104 is described below with reference to FIG. 1 through FIG. 25 . In the first step S1 of the method, the positioning unit 110 is controlled to move the measuring tip 106 in the y-direction so that the vertex 168 of the measuring tip 106 contacts the surface 172 of the sample carrier 120 or the surface 174 of the sample 102 in a testing area 176 of the sample carrier 120 or the sample 102, and the measuring tip 106 leaves a first track 178 (e.g., a scratch track 178) on the surfaces 172, 174. Specifically, the first track 178 is arranged parallel to the y-direction. FIG6 illustrates the testing area 176 of the sample 102. However, in other examples, the method can also be applied to a testing area of ​​the sample carrier 120 (not shown here). As illustrated in FIG7 , the vertex 168 of the measuring tip 106 is thus scratched in the y-direction along the surfaces 172, 174 of the testing area 176 in step S1. In a second step S2 of the method, the image recording device 128 is controlled to record at least one image 260 ′ of the test area 176 , in which the first trajectory 178 ( FIG. 7 ) is at least partially captured. In a third step S3 of the method, the x-position x of the vertex 168 of the measuring tip 106 with respect to the x-direction is determined based on the first trajectory 178 captured in the image 260 ′. 1. For example, as shown in FIG8 , a straight line 180 is fitted to the first trajectory 178. Thus, the x-position x of the actual vertex 168 of the tip 106 is measured. 1 is determined as the x-position x of the line 180 G For example, the actual x-position x of vertex 168 is 1 relative to the x-position x of the apparent apex 170 of the measuring tip 106 2 is determined, for example, as an x-offset Δx. In the fourth step S4 of the method, positioning unit 110 is controlled to move measurement tip 106 along the x-direction, so that apex 168 of measurement tip 106 contacts surface 174 of sample 102 (or surface 172 of sample support 120 in other examples) in testing area 176, and measurement tip 106 leaves a track 182 (e.g., scratch track 182) on second surface 174. Specifically, second track 182 is arranged parallel to the x-direction. As illustrated in FIG. 9 , apex 168 of measurement tip 106 is thus scratched along surface 174 of testing area 176 in the x-direction in step S4. In a fifth step S5 of the method, the image recording device 128 is controlled to record at least one further image 260 ″ of the test area 176 , in which the second trajectory 182 ( FIG. 9 ) is at least partially captured. In a sixth step S6 of the method, the y-position y of the vertex 168 of the measuring tip 106 with respect to the y-direction is determined based on the second trajectory 182 captured in the image 260 ”( FIG. 9 ). 1 '. For example, as shown in FIG9 , a straight line 184 is fitted to the second trajectory 182. Thus, the y-position y of the actual vertex 168 of the tip 106 is measured. l 'The system is determined as the y-position y of the straight line 184 G For example, the y-position y relative to the apparent apex 170 of the measuring tip 106 2' to determine the y-position y of the actual vertex 168 1 ', for example as a y-offset Δy. In the examples shown in FIG6 to FIG9 , the y-position y of the actual vertex 168 1, y 1′ corresponds to the y-position y of the apparent apex 170 of the measuring tip 106 2, y 2', so the y-offset Δy is equal to zero. Thus, through steps S1 to S6, the exact x and y-position x of the actual apex 168 of the measuring tip 106 can be determined. 1, y 1(x 1', y 1 ′) (eg relative to the apparent apex 170 ), even though only the apparent apex 170 of the measuring tip is visible in the SEM images 260 , 260 ′, 260 ″. Within the scope of the proposed method, an approach curve 186 ( FIG. 10 ) can optionally be determined for the deflection D ( FIG. 2 ) of the extension arm 108 as the measuring tip 106 approaches the sample 102 parallel to the z-direction. In particular, attractive and / or repulsive forces act on the free end 114 of the extension arm 108 in a manner that depends on the z-position Pz of the base end 112 of the extension arm 108, and these forces attract the free end 114 of the extension arm 108 toward the sample 102 or move it away from the sample 102. For the approach curve 186 ( FIG. 10 ) for the deflection D of the free end 114 of the extension arm 108, only the distance ranges in the z-direction in which only repulsive forces act on the free end 114 of the extension arm 108 and / or in which the repulsive forces are greater than the attractive forces are considered. By approaching the curve 186, the safe deflection D of the free end 114 of the extension arm 108 in the z-direction can be determined. S( FIG. 10 ), in this case, the measuring tip 106 does not damage the sample 102 . The free end 114 of the extension arm 108 is safely deflected D S Specifically, it corresponds to the safe minimum z-distance A between the base end 112 of the extension arm 108 and the sample 102. S (ie, in the z-direction). Determining the approach curve 186 is advantageous because the exact z-position z of the apex 168 ( FIG. 5 ) of the measuring tip 106 is Specifically, although the z-position Pz of the base end 112 of the extension arm 108 is set and provided by the positioning unit 110, the exact z-position z of the apex 168 of the measuring tip 106 is 1 is generally unknown due to the varying deflection D of the free end 114 of the extension arm 108 and due to a possible bending B of the measuring tip 106 in relation to the extension arm 108 . In a first step S1' of the method, the positioning unit 110 is controlled to move the base end 112 of the extension arm 108 in the negative z-direction. As a result, the z-distance A ( FIG. 5 ) between the base end 112 of the extension arm 108 and the sample 102 is reduced, and the measurement tip 106 is brought closer to the sample 302 within the test area 188 ( FIG. 11 ) of the sample 302. Specifically, the test area 188 is located outside of and / or at a distance from the structures 362, 364 (e.g., absorbent structures) of the sample 302. In the second step S2 ′ of the method, the deflection detection device 150 (eg, the light pointer device 150 , FIG. 2 ) repeatedly receives the range D of the z-deflection D about the free end 114 of the extension arm 108 . 1. D 2. D 3 ( FIG. 10 ), as a function of the set z-position Pz of the base end 112 of the extension arm 108 (i.e., the z-distances A, A between the base end 112 of the extension arm 108 and the sample 302). 1. A 2. A 3; see Figures 5 and 10). Specifically, step S2' is performed simultaneously with step S1'. In other words, during the displacement of the measuring tip 106 in the negative z-direction (i.e., when the measuring tip 106 approaches the sample 302), the deflection detection device 150 simultaneously or repeatedly measures the z-deflection D of the free end 114 of the extension arm 108. In the example of Figure 10, the base end 112 of the extension arm 108 is brought close to the sample 102 until the distance A 3. At this time, the deflection D 3 acts on the free end 114 of the extended arm. Specifically, the distance A in FIG10 decreases from left to right, so that A 3 is less than A 2, and A 2 is less than A 1. In a third step S3 ′ of the method, an approach curve 186 ( FIG. 10 ) is determined. The approach curve 186 specifies the range D of the deflection D of the free end 114 of the extension arm 108 . 1. D 2. D 3 is the distance A and A between the base end 112 of the extension arm 108 and the sample 302. 1. A 2. A 3. As shown in FIG10 , the deflection D of the extension arm 108 decreases as it approaches the base end 112 of the extension arm 108. Therefore, the measurement tip 106 also approaches the sample 102, 302. In other words, the repulsive force acting on the measurement tip 106 decreases as the measurement tip 106 approaches the sample 102. It can also be said that the atomic force microscope 104 functions as a force sensor in this process, performing force-distance spectroscopy. In a fourth step S4 ′ of the method, at least one image 360 ​​of the sample 302 is received, wherein the test area 188 ( FIG. 11 ) is at least partially captured. In a fifth step S5' of the method, it is determined whether the sample 302 is damaged in the test area 188 based on the received at least one image 360. For example, the measuring tip 106 of FIG11 does not damage the test area 188 (ie, the material 190 of the test area 188). In a sixth step S6' of the method, if it is determined in step S5' that the sample 302 is not damaged in the test area 188, the minimum z-deflection D of the approach curve 186 determined in step S3' is 3 and / or minimum z-distance A 3 is determined as the safe z-deflection D of the free end 114 of the extension arm 108 3. D S Or it is determined as the safe z-distance A between the base end 112 of the extension arm 108 and the sample 102 3. A S . Optionally, in the method, a plurality of approach curves 186, 186', 186" (FIG. 12) are determined based on different test areas 188, 188', 188" (FIG. 11) in each case. The test areas 188, 188', 188" differ from one another, in particular, the type of material 190, 190', 190" of the respective test areas 188, 188', 188" differs. Subsequently, at least one image 360 ​​is recorded using an image recording device 128, in which the plurality of test areas 188, 188', 188" is at least partially captured. Furthermore, at least one image 360 ​​is recorded for each test area 188, 188', 188". For each determined approach curve 186, 186', 186", the received at least one image 360 ​​is then used as a basis to determine whether the sample 302 is damaged in the respective test area 188, 188', 188". In the example of FIG. 11 , the measuring tip 106 does not damage the corresponding material 190, 190' of the test areas 188, 188'. For example, the scratch 200 left by the measuring tip 106 is illustrated for the test area 188" as an example of damage to the material 190" of the test area 188". For example, it is therefore determined for the test areas 188, 188' that the sample 302 is not damaged. Furthermore, damage to the sample 302 is determined by the instance of the test area 188". Next, if the sample 302 is determined to be free of damage in the respective test areas 188, 188', the safety deflection D of the respective approach curves 186, 186' is stored. S 、D S ' (Fig. 12), as a function of the corresponding material 190, 190' of the respective test area 188, 188'. In the proposed method, the measuring tip 106 can also be selectively and automatically positioned at a suitable predetermined working distance Δz from the sample 402. 2, as illustrated in FIG13. Specifically, the positioning unit 110 can be provided to initially control the movement of the measuring tip 106 in the negative z-direction so that the measuring tip 106 contacts the sample 102 (left image in FIG13). Here, the distance Δz between the measuring tip 106 and the sample 402 is 1 equals 0 (Δz 1=0). Next, using the contact between the measuring tip 106 and the sample 402 as a starting point, a predetermined working distance Δz to be set between the measuring tip 106 and the sample 402 is provided. 2. To this end, the positioning unit 110 can be controlled to move the measuring tip 106 in the direction of the sample 402 and / or the further positioning unit 124 ( FIG. 1 ) can be controlled to move the sample 402 arranged on the sample carrier 120 in the direction of the measuring tip 106. Specifically, the positioning unit 110 and / or the further positioning unit 124 are controlled so that the measuring tip 106 and the sample 402 are spaced apart by a predetermined distance Δz. 2 (right image in Figure 13). By setting a predetermined working distance Δz 2, so that images of the sample 402 (e.g., using the scanning electron microscope 128 of FIG. 1 ), in which at least a portion of the measuring tip 106 is captured, can be compared with one another in an improved manner. This allows for better monitoring of image-monitoring processes, such as, for example, manipulating processes using the measuring tip 106 (e.g., displacing and / or removing particles 132 on the sample 102, 402). Optionally, the proposed method provides a fully automated iterative process for removing particles 532, as shown in Figure 14. This significantly simplifies the removal of particles 532. In the first step S1″ of the iterative particle removal process, a removal trajectory T (e.g., a linear removal trajectory T) is provided for removing the particles 532 disposed on the sample 502. Specifically, the removal trajectory T is located in an xy-plane E ( FIG. 3 ) that is spanned by the x-direction and the y-direction and corresponds to the xy-position (x P , y P 3 ). For illustrative purposes, the particle 532 is depicted exaggerated relative to the measuring tip 106 in FIG14 . However, in reality, the particle 532 in FIG14 (and in the other figures) may be very small relative to the measuring tip 106. In the second step S2″ of the iterative particle removal process, the positioning unit 110 is automatically controlled to position the measuring tip 106 at a first predetermined z-distance Δz from the sample 502 in the z-direction. 3 (e.g., Δz 3=50 nm). In the third step S3″ of the iterative particle removal process, the positioning unit 110 is automatically controlled to move the measuring tip 106 laterally 204 (i.e., in the x- and / or y-direction) along the determined removal trajectory. Specifically, during the process, the measuring tip 106 and the sample 502 are kept at the first predetermined z-distance Δz set in step S2″. 3. In the example of FIG14 , the movement of the measuring tip 103 in step S3 ″ is only along the x-direction. However, in other examples, the movement of the measuring tip 103 in step S3 ″ may also be performed along the x-direction and the y-direction or only along the y-direction. Optionally, in method step S3 ″, the measuring tip 106 is incrementally moved in a separate step 208 by a predetermined lateral distance Δl 1 (e.g., Δl 1 = 20 nm). As illustrated in FIG15a, for different lateral distances Δl in each case 1. Δl 2 Method step S3 can also be performed multiple times. In this case, the lateral distance Δl 1. Δl 2 increases with increasing number of repetitions (e.g., Δl 1=20 nm and Δl 2=50 nm). In a fourth step S4 ″ of the iterative particle removal process, the positioning unit 110 is fully automatically controlled to move the measuring tip 106 in the positive z-direction 206 ( FIG. 14 ) away from the sample 502 . In a fifth step S5 ″ of the iterative particle removal process, it is determined fully automatically whether the particle 532 has adhered to the measuring tip 106 . In the sixth step S6″ of the repeated particle removal step, for one or more additional predetermined z-distances Δz 4. Δz 5. Δz 6. Δz 7 Steps S2" to S5" are repeated fully automatically, as illustrated in FIG15b. In particular, the z-distance Δz is further predetermined. 4. Δz 5. Δz 6. Δz 7 gradually becomes smaller than the first predetermined z-distance Δz 3 (e.g. Δz 4 = 40 nm, Δz 5=30nm, Δz 6=20 nm, Δz 7=10 nm). Specifically, for the gradually decreasing z-distance Δz 4. Δz 5. Δz 6. Δz 7 Steps S2″ to S5″ are repeated automatically until it is determined that the particle 532 is adhered to the measuring tip 106. Optionally, a further fully automated iterative process for removing particles 532 is provided in the proposed method, as shown in FIG. 16 a to FIG. 16 c . In a first step of the method, the positioning unit 110 is controlled to position the measuring tip 106 on the surface 538 of the sample 502 and adjacent to the particle 532 on the surface 538 of the sample 502. Thus, the base point 112 of the extension arm 108 is located at a first predetermined z-distance z from the sample 502 in the z-direction. 8 places. In a second step of the method, the positioning unit 110 is controlled to move the measuring tip 106 laterally (ie in the x- and / or y-direction) in order to detach the particle 532 from the surface 538 . In a third step of the method, it is determined whether the particle 532 is on the surface 538 or has moved on the surface (ie, changed its position on the surface 538 from its initial position in the first step). For example, the third step is performed by the image recording device 128 ( FIG. 1 ). For example, in both the first step and the third step, the image recording device 128 records images of the captured particles 532 . In a fourth step of the method, for one or more further predetermined z-distances z between the base point 112 of the extension arm 108 and the sample 502 9. z 10 (Fig. 16b, 16c), repeat the first to third steps. Specifically, another predetermined z-distance z 9. z 10 gradually becomes smaller than the first predetermined z-distance z 8. As a result, a gradually increasing force is exerted on the measuring tip 106 and thus on the particle 532. As can be seen from Figures 16b and 16c, the extension arm 108 gradually bends in the process. For one or more further predetermined z-distances z between the base point 112 of the extension arm 108 and the sample 502 9. z 10 The first to third steps are repeated until it is determined that the particles 532 on the surface 538 have moved. In particular, steps 1 to 4 are performed fully automatically. The z-distance z between the base point 112 of the extension arm 108 and the sample 502 is 8. z 9. z 10 By repeating the steps of the method, only the force precisely required to separate the particle 532 from the surface 538 can be applied to the measurement tip 106 without causing damage to the measurement tip 106 and / or the sample 538 . Optionally, the proposed method provides for fully automated movement and lifting of the measurement tip 106, as shown in FIG17 . To this end, the positioning unit 110 is first controlled to laterally move 210 ( FIG17 ) the measurement tip 106 in the direction of a particle 632 disposed on the sample 602 . Next, a determination is made as to whether the particle 632 adheres to the measurement tip. Adhesion of the particle 632 to the measurement tip 106 can be checked based on various methods described below. If adhesion of the particle 632 to the measurement tip 106 is determined, the positioning unit 110 is controlled to perform lifting movements 212 , 214 of the measurement tip 106 . As shown in the center of FIG17 , in only the first variant, the lifting movements 212 , 214 can be movements 212 of the measurement tip 106 in the positive z-direction. Furthermore, in a second variant, the lifting movements 212 , 214 can be movements 214 of the measurement tip 106 along a curved trajectory 215 that curves from an initial lateral movement to a movement in the positive z-direction in the region of the particle 632 . Thus, the movement and lifting processes 210 , 212 , 214 of the measuring tip 106 (possibly required to pick up the particles 632 from the sample surface) can be performed fully automatically, including checking whether the particles 632 are adhered to the measuring tip 106 . Optionally, the proposed method can include a (e.g., fully automated) check of whether a particle 632 ( FIG. 17 ) is adhered to the measuring tip 106 . To this end, the positioning unit 110 (e.g., as shown in FIG. 14 and / or FIG. 17 ) is controlled to move the measuring tip 106 laterally and / or in the positive z-direction, so that the measuring tip 106 can be used to pick up a particle 632 disposed on the sample 602 . Whether the particle 632 is adhered to the measuring tip 106 can then be determined according to one or more of the following four variations. In a first variant, whether the particle 632 adheres to the measuring tip 106 ( FIG. 2 ) is determined based on the degree of lateral deflection of the extension arm 108 (ie in the x and / or y-direction) received from the deflection detection device 150 . For example, the lateral deflection of the extension arm 108 may be determined by the light director device 150. Specifically, a lateral force acting between the measurement tip 106 and the sample 102 may cause a rotation R of the free end 114 of the extension arm 108 about the x-direction. Therefore, the lateral deflection of the extension arm 108 can be determined by the light director device 150 , for example, by detecting the degree of rotation R of the free end 114 of the extension arm 108 about the x-direction. In a second variation, whether particles 732, 732' are adhered to the measurement tip 106 is determined based on a change in brightness ΔB of particles 732 and / or a change in contrast of particles 732 in images 760, 760' of particles 732, 732' (e.g., in electron microscope images and / or ion microscope images), as shown in Figures 18 and 19. In addition to particles 732, 732', at least a portion of the measurement tip 106 is captured in a plurality of received images 760, 760' of the sample 702. In image 760 (Figure 18), particle 732 has not yet adhered to the measurement tip 106. In contrast, in image 760' (Figure 19), the brightness B2 of particle 732' is significantly increased compared to the brightness B1 of particle 732 in image 760 (i.e., particle 732' in image 760' is brighter than particle 732 in image 760). Specifically, the brightness change ΔB is caused by the difference between brightnesses B1 and B2. In other words, the contrast between the particle 732′ and the measuring tip 106 in FIG19 is greater than the contrast between the particle 732′ and the measuring tip 106 in FIG18 . This indicates that the particle 732′ in FIG19 is charged due to adhesion, and therefore indicates that the particle 732′ is shown to be adhered to the measuring tip 106 in FIG19 . In a third variant, particle 832' adhered to measuring tip 106 is determined based on the migration of particles 832, 832' away from the fixed, set focus of image recording device 128, as shown in FIG20 . This is because it indicates that particle 832' is lifted along with measuring tip 106. Specifically, based on images 860, 860', it is determined that particle 832 is initially in the focus of image recording device 128 (image 860, left side of FIG20 ), and that particle 832' is no longer in the focus of image recording device 128 in the subsequent image 860' (right side of FIG20 ). In a fourth variation, an image 160 ( FIG. 3 ) of particle 132 is recorded using image recording device 128 with an autofocus setting focused on particle 132. Furthermore, the auto-adjustment ΔF ( FIG. 21 ) exceeds a predetermined threshold ΔF for autofocus focused on particle 132. S Afterwards, the z-position Pz of the particle 132 has changed significantly, and this indicates that the particle 132 has been lifted (in the positive z-direction) together with the measuring tip 106. FIG21 shows the change ΔF of the autofocus. For example, a value greater than a critical value ΔF may be S Automatic adjustment of ΔF 1 is to be interpreted as meaning that the particle 132 moves in a manner corresponding to adhesion to the measuring tip 106 . Optionally, the proposed method provides for fully automated centering of the measuring tip 106 and the sample carrier 120. Specifically, the atomic force microscope 104 includes a sample carrier device 126 having a mount 122, the sample carrier 120 arranged on the mount 122 for transverse movement, and an additional positioning unit 124 for laterally moving the sample carrier 120 relative to the mount 122 in the x- and y-directions. The sample carrier 120 is also, for example, rotatably mounted on the mount 122, such that it can be rotated about the x-, y-, and / or z-directions with the aid of the additional positioning unit 124. In a first step S1″′ of the method, the positioning unit 110 is controlled to position the measuring tip 106 fully automatically at the initial position Px 0, Py 0 (eg, at x=0 and y=0), information about the x-direction and the y-direction is preset in the positioning unit 110 . In a second step S2 ′″ of the method, at least one image 160 of the sample 102 is recorded, wherein particles 132 disposed on the sample 102 are captured. In the third step S3″′ of the method, the lateral position x of the particle 132 captured in at least one image 160 is determined by image processing. P , y P (Figure 3). In the fourth step S4'' of the method, the positioning unit 124 is further controlled to move the sample carrier 120 laterally relative to the mounting base 122, wherein the lateral position x of the particle 132 is P 、y P Corresponds to the initial position Px of the measuring tip 106 with respect to the x-direction and the y-direction 0. Py 0. Using the described methods, the x-, y-, and / or z-position of the apex 168 of the measurement tip 106 can be determined more accurately, thereby enabling more precise manipulation of the sample 102 using the measurement tip 106. Furthermore, desired nanoscale manipulation using the measurement tip 106 can be facilitated and / or automated in various ways. Figures 26 to 28 illustrate another computer-implemented method for manipulating a sample 102 using a nanomanipulator 104 (Figure 1). The nanomanipulator 104 includes a measuring tip 106 for manipulating the sample 102 and a positioning unit 124 for moving the measuring tip 106. Only the measuring tip 106 of the nanomanipulator 104 is visible in Figure 26; for other components of the nanomanipulator 104, such as the positioning unit 124, a sample carrier 120 on which the sample 102 is arranged, and an image recording unit 128, reference is made to Figure 1 and its description. The x-direction and y-direction of the nanomanipulator 104 are each arranged parallel to the main extension plane E of the sample 102 and / or the sample carrier 120 and perpendicular to each other. The sample 120 has a nanostructure 900 on its surface 902, which is used to determine the actual vertex 904 of the measuring tip 106. In a first step S1″″ of the method, the positioning unit 124 is controlled to move the measuring tip 106 laterally (in the x- and / or y-direction) from the initial lateral coordinate x A Move to the horizontal end coordinate x E , to scan the nanostructure 900. Raster scan data 906 is created in the process. For example and for illustrative purposes, the corresponding x-coordinate is designated as the horizontal initial coordinate x in FIG. 26 . A and horizontal end coordinate x E However, the horizontal start coordinate and the horizontal end coordinate each have an x-coordinate and / or a y-coordinate as a position specification. In the second step S2″ of the method, the nanostructure coordinates x of the highest points 908 and 910 of the nanostructure 900 are determined in the raster scan data 906. N . In FIG26 , the x-coordinate can also be designated as the nanostructure coordinate x N However, the nanostructure coordinate x N It is also possible to have x- and / or y-coordinates as position specifications. In the third step S3"" of the method, the coordinate x of the nanostructure is determined. N and the horizontal end coordinate x E A first lateral distance C1 therebetween. In a fourth step S4″ of the method, at least one image 912 ( FIG. 27 ) of the sample 102 is recorded, from which the measuring tip 106 and the nanostructure 900 are at least partially captured. In this case, the actual vertex 904 of the measuring tip 106 (which is not visible in the image 912 ) is located at the lateral end coordinate x E FIG27 also shows the apparent apex 914 of the measuring tip 106 visible in the image 912. In a fifth step S5″” of the method, a distance between the apparent vertex 914 of the measuring tip 106 and the nanostructure 900 (eg, the nanostructure coordinate x) is determined in the image 912. N ) of a second distance C2 (e.g., through image analysis). In a sixth step S6"" of the method, the lateral position x of the actual apex 904 of the measuring tip 106 is determined based on the difference between the first distance C1 and the second distance C2. E , x' E For example, the second distance C2 is subtracted from the first distance C1 to determine a third distance C3 between the apparent vertex 914 and the actual vertex 904 of the measurement tip 106 . Nevertheless, the position x of the actual vertex 904 of the measuring tip 106 which is not visible in the image 912 can be determined in this way. E , x' E . The lateral dimension G ( FIG. 26 ) of the nanostructure 900 used to determine the actual apex 904 of the measuring tip 106 is, for example, 30 nm or less, 20 nm or less, 10 nm or less and / or 5 nm or less. In the example of Figures 26 and 27, the nanostructure 900 used to determine the actual apex 904 of the measuring tip 106 has a spherical shape and / or a spherical surface. However, as shown in FIG. 28 , a nanostructure 916 for determining the actual apex 904 of the measuring tip 106 may also have, for example, a tip 918 that tapers, for example, in a direction away from the sample surface 902 . According to another embodiment, a system, apparatus, and method for positioning the tip of a nanomanipulator 104 on a sample 102 are provided and described below. The apparatus can be similar to the apparatus described above with reference to FIG. 1 and FIG. Therefore, unless otherwise noted, the aforementioned components and details can also be present in or applicable to the following system. The disclosed method can be implemented at least in part on a computing system (e.g., the aforementioned control device 140). FIG30 shows a schematic diagram of a system 1000 for detecting a frequency offset of a drive signal. System 1000 includes an arm deflection system 1001 (e.g., beam deflection system 1100 described below), a frequency control system 1002, and an amplitude control system 1003. Frequency control system 1002 includes a phase detector 1004, a first feedback unit 1005 (e.g., an integrator), and a controllable oscillator 1006 (e.g., a voltage-controlled oscillator or a numerically controlled oscillator). Amplitude control system 1003 includes an amplitude detector 1007 (e.g., a squared mean detector) and a second feedback unit 1008 (e.g., a proportional-integral (PI) controller). The first output signal provided by the frequency control system 1002 and the second output signal provided by the amplitude control system 1003 are combined by an integrator 1009 to provide a drive signal (i.e., an excitation signal, such as A sin(2πf t), where A is the second output signal corresponding to the amplitude provided by the amplitude control system 1003, sin(2πf t) is the first output signal provided by the frequency control system 1002, where f is the current operating frequency of the controllable oscillator 1006, and t is time) to the excitation unit of the cantilever arm deflection system 1001. The excitation unit 1110 may include an excitation piezoelectric element as shown in FIG31 or a similar actuator that converts an electrical drive signal into mechanical vibration, thereby causing the cantilever arm 108 attached thereto to vibrate. The oscillation of the cantilever arm 108 or other portion of the tip attached thereto can be detected as a deflection signal 1011 by a four-quadrant photodiode 1154, as shown in FIG31, or a similar sensor that converts the mechanical oscillation back into an electrical control signal. Note that the quadrant photodiode 1154 can also provide a transverse signal 1012. However, the transverse signal is not required to implement the control loop described below. Frequency control system 1002 tracks the phase component of deflection signal 1011 by forming a phase-locked loop (PLL). Specifically, phase detector 1004 compares deflection signal 1011 with the current oscillator output signal 1018 to output a corresponding phase signal 1013, e.g., a phase error signal. First feedback unit 1005 integrates phase signal 1013 to provide a frequency control signal 1014 indicating a frequency offset (i.e., frequency offset dF) based on integrated phase signal 1013 and a phase setpoint 1015. Under resonant drive conditions, the phase angle between excitation signal 1010 and deflection signal 1011 should approach 90°. However, due to delays in processing circuitry or other imperfections, the phase setpoint may be set to a value above or below 90°, as described in further detail below regarding the determination of resonant characteristics. Frequency control signal 1014 is fed back to controllable oscillator 1006 to adjust the frequency of oscillator output signal 1018 provided by oscillator 1006 to align with the resonant frequency of the cantilevered arm. Amplitude control system 1003 provides an amplitude control loop. Specifically, amplitude detector 1007 detects the current signal strength of deflection signal 1011 and provides a corresponding amplitude signal 1016 to second feedback unit 1008. Based on amplitude signal 1016 and amplitude setpoint 1017, second feedback unit 1008 provides amplitude feedback signal 1018 to maintain the amplitude of the maximum deflection of the extension arm close to the desired value. FIG31 illustrates a schematic diagram of an exemplary configuration of a beam deflection system 1100 (e.g., an extension arm deflection system 1001 of system 1000 ). As shown, a tip 106 (e.g., a measurement tip or a manipulation tip) is attached to an extension arm 108 . The tip 106 and the extension arm 108 together form a probe 1106 for probing or manipulating a sample 1102 (e.g., sample 106 ). The probe 1106 can be mechanically actuated (e.g., actuated) by an actuation unit 1110 . For example, a first end of the extension arm 108 (i.e., end 112 in FIG1 and FIG2 ) can be attached to a piezoelectric element 1110 , while the tip 106 can be attached to a second end (e.g., the opposite end) of the extension arm 108 (i.e., end 114 in FIG1 and FIG2 ). Light from a light source 1152 , such as an LED or laser diode, is reflected from the second end to a quadrant photodiode 1154 to detect deflection of the extension arm. Note that the use of four-quadrant photodiodes 1154 allows for the generation of different control signals. Specifically, the first deflection signal in the z-direction, namely the vertical deflection value DFL, determines the lateral deflection of the extension arm in the x / y directions, namely the lateral deflection value LAT. The lateral deflection value LAT is calculated as the sum of the areas of the left two diodes minus the sum of the areas of the right two diodes. Similarly, the vertical deflection value DFL is calculated as the sum of the areas of the top two diodes minus the sum of the areas of the bottom two diodes. Additionally, a sum signal SUM over all four diode areas can be provided. FIG32 shows the resonance curves of the probe 1106 in vacuum and in air, respectively. Note that the two curves are significantly different, as the peak in vacuum is much narrower and much higher than the peak of the same probe 1106 oscillating in air (shown at a 50x magnification in the same figure). One reason for this is that the air damps the oscillations. For the exemplary probe 1106, this results in a much lower Q value of 500 instead of 50,000, and a shift in the resonant frequency from approximately 320,150 Hz to 320,000 Hz. Note further that due to the higher damping in air, the amplitude of the oscillations of the probe 1106 in air changes more rapidly than the amplitude of the oscillations of the probe 1106 in vacuum (e.g., at pressures equal to or below 10e). -3 mbar). Figure 33 shows a first method for detecting the interaction between the probe 1106 and the sample based on tracking the amplitude signal. The method shown in Figure 33 is based on detecting the change in the oscillation amplitude and can be referred to as amplitude modulation (AM) detection. In AM detection, the extended arm 108 is excited with a fixed amplitude and fixed frequency signal and a constant (controlled) amplitude. Curve 2 of Figure 33 shows the resonance curve without tip-sample interaction. In contrast, curve 1 shows the resonance curve with repulsive tip-sample interaction, which is located to the right of curve 2, i.e. at a higher resonant frequency. In AM detection, the measured amplitude signal is used as input for topological feedback. Row 4 shows the oscillation amplitude without tip-sample interaction. In contrast, row 5 shows the oscillation amplitude with repulsive tip-sample interaction. As the resonant frequency increases, the amplitude change due to the tip-sample interaction always reduces the observed amplitude. Therefore, the operating point of the relevant excitation signal is selected to be far away from the resonant frequency, as shown by line 3 of Figure 33. Figure 34 shows a second method for detecting the interaction between the probe 1106 and the sample based on the tracking frequency signal according to another embodiment of the present invention. The method shown in Figure 34 is based on directly detecting the change in the oscillation frequency and can be referred to as frequency modulation (FM) detection. In contrast to the AM detection method, in the FM detection method, the oscillator (i.e., the extension arm 108 and / or other components of the probe 1106) is driven (i.e., excited) at its resonant frequency. As previously described, this can be implemented using a PLL or similar frequency control circuit (e.g., reference numeral 1002 ). Furthermore, an amplitude feedback circuit (e.g., reference numeral 1003 ) can be used to control the amplitude of the oscillation to remain constant. Curve 1 in FIG. 34 shows a first resonance curve with repulsive tip-sample interaction. Curve 2 shows a second resonance curve without tip-sample interaction. As previously described, as the tip 106 of the probe 1106 approaches the sample 102, the resonant frequency shifts upward. In the FM detection method, the frequency shift signal dF serves as the input signal for the topological feedback. This signal can be provided by a PLL or similar frequency control circuit as previously described. Note that the use of a PLL provides a very fast response signal to changes in the resonant frequency, thereby improving the response to tip-sample interaction, particularly under vacuum or reduced pressure. 35 illustrates a flow chart of a partially or fully computer-implemented method for positioning a nanomanipulator probe 1106 on a sample using the system from FIG. 30 and the aforementioned FM detection method, according to one embodiment. In step S20 , the resonant characteristics of probe 1106 are measured. This is performed without tip 106 contacting or approaching the tip. For example, the tip may be located at a significant distance from probe 1106, i.e., between 50 and 500 μm, e.g., 100 μm, where forces (e.g., attractive or repulsive forces) acting between tip 106 and sample 102 are negligible. For example, a frequency sweep signal may be used to determine the resonant frequency (i.e., natural frequency or harmonic frequency) of probe 1106. Furthermore, other parameters may be determined, including a Q value and a phase setpoint value corresponding to the phase difference between the excitation signal and the deflection signal specific to system 1000. Alternatively, some or all of the characteristics of probe 1106 may be set as stored values, e.g., by the industry or from a public library. The actual placement of the probe 1106 (ie the approach of the tip 106 to the surface of the sample 102 ) may be performed in several stages and / or using corresponding operating modes. During the first or approach phase, FM detection can be employed to avoid unwanted hard contact points between tip 106 and probe 1106. FM detection mode provides high sensitivity for detecting attractive or repulsive forces. During this phase, small electrostatic attractive forces can be detected and analyzed. If the electrostatic force exceeds a predetermined threshold, the approach can be aborted to prevent damage to probe 1106. This operating mode can be referred to as the system's dynamic mode. In dynamic mode, the probe 1106 is actively driven and mechanically oscillated. In other words, in dynamic mode, an excitation signal 1010 is provided to the excitation unit 1110. In dynamic mode, multiple parameters can be monitored and used to determine the approach of the tip 106 to the surface of the sample 102 and / or various error conditions that may be encountered. Because the system 1000, including the extension arm deflection system 1001 and the frequency control system 1002, forms a control loop for tracking the resonant frequency of the tip, this mode can also be referred to as closed-loop operation. Some or all of the control signals provided by the frequency control system 1002 and the amplitude control system 1003 can be used to monitor and / or control the first approach phase (e.g., the initial phase of the landing operation). For example, in dynamic mode, the amplitude feedback signal 1019, phase signal 1013, and frequency control signal 1014 derived from the deflection signal 1011 can be monitored and analyzed during closed-loop control. Additionally, further system parameters may be monitored and analyzed, including open loop parameters like the SUM, LAT, and DFL signals provided by sensor 1154. It is also possible to monitor the vertical velocity of tip 106. For example, the velocity of the fine drive of the positioning unit may be monitored. In step S21, a resonant drive signal is provided to the excitation unit 1110. Initially, the piezoelectric actuator can be driven with the known natural resonant frequency of the probe 1106, such as determined in step S20. Once oscillation begins, the control loop(s) of the system 1000 maintain the oscillation while tracking the resonant frequency of the probe 1106. Furthermore, at least one of the aforementioned parameters is selected to define a stopping condition for the first phase of the approach. For example, the approach can be stopped when the beat frequency or frequency offset dF (e.g., frequency control signal 1014) exceeds a threshold value indicating an upper frequency of the tip-probe interaction corresponding to a repulsive force. Alternatively or additionally, the approach can be stopped when the oscillation amplitude falls below a lower amplitude, indicating that the oscillation is partially blocked by the sample, i.e., that the probe 1106 is partially in contact with the sample. Abnormally large amplitudes, abnormally small or large phase signal values, or negative beat frequency dF can indicate various error conditions, such as uncontrolled oscillation of the extension arm, loss of PLL lock, or high electrostatic charge of the probe 1106 and / or the sample. In step S22, a first approach phase is performed. For simplicity, the following example uses coarse and fine actuation of the positioning unit 110 to control the probe 1106. However, in other embodiments, all or part of the relative movement can be effected by moving the sample carrier 120 and / or by a single platform positioning unit 110 used to move the probe 1106. For example, the coarse and / or fine actuation of the positioning unit 110 can be used simultaneously or intermittently to reduce the distance between the tip 106 and the sample 102 in the z-direction. Specifically, the tip 106 can first be advanced using the fine actuation. Then, if no sample is detected within the range of the fine actuation, the fine actuation returns to its minimum position and the coarse actuation advances by a corresponding amount. This method continues until one of the stopping criteria is met. Assuming no error conditions are encountered, the approach should terminate when a repulsive force begins to act between the tip 106 and the sample 102, resulting in a significant upward shift in the resonant frequency, i.e., a dF value exceeding a predefined threshold. The tip 106 now approaches the surface of the sample 102 . Optionally, in step S23, the z-position is stored. Alternatively, the tip 106 may be retracted a small, predetermined amount to avoid accidental contact. For example, the control unit may retract the tip by a fixed distance, such as one or a few nanometers, or by multiple steps of a digital control parameter Zfine used to control fine actuation. Optionally, the system switches to a second operating mode, hereinafter referred to as static mode, in order to remove particles 132 from the surface 138 of the sample 102 or to perform other manipulations of the sample 102 or its surface 138. In the static mode, the tip 106 may be approached even further to the sample 102 in a second approach phase or phases, as described below. In static mode, probe 1106 is not actively driven. Therefore, the deflection of the extension arm is determined by the attractive and repulsive forces between probe 1106 and sample 1102. In other words, in static mode, no excitation signal is provided to excitation unit 1110. Similar to the above, in static mode, multiple parameters can be monitored and used to determine the tip's approach to the surface of sample 102 and / or various error conditions that may be encountered. This mode is also referred to as open-loop operation, as the control loop for tracking the probe's resonant frequency is enabled (i.e., disabled), and only the remaining system parameters, including open-loop parameters such as the SUM, LAT, and DFL signals provided by sensor 1154, can be monitored and analyzed. The vertical velocity of tip 106 can also be monitored. For example, the velocity of the positioning unit's fine drive can be monitored. In step S24, the drive signal of the probe 1106 is deactivated to stop the oscillation of the extension arm 108. In addition, a set of different stop conditions are selected to control further approach. Note that at this stage the tip 106 has already approached the surface 138 of the sample 102. Therefore, a parameter indicating direct contact between the tip 106 and the particle 132 or the surface 138 of the sample 102 can be used to stop further approach. For example, a deflection signal of the extension arm 108, such as the vertical deflection signal DFL, can be directly used as a stop condition for further approach. In addition, as mentioned above, an unexpected low or high speed of the positioning unit 110 can be used as a stop condition or to indicate an error. In step S25, further approaching is performed. For example, the further method can be implemented by activating fine drive to gradually approach the sample surface. Coarse drive can also be used, based on the first stopping criteria used in the first approaching stage. Approaching is stopped when at least one of the second stopping criteria is met. For example, further approaching can be stopped when tip 106 physically contacts the surface of sample 102 or particles 132 located on surface 138. In a further optional step S26, the position of the probe 1106 relative to the sample 102 can be optimized using a combination of coarse and fine drive to control the approach. In this case, the z-position of the contact position can be stored to provide a good dynamic range for the fine drive during particle or surface manipulation. The tip 106 can then be retracted by the fine drive. For example, the fine drive can be pulled completely away from the surface. Thereafter, the coarse drive can be controlled so that the contact position is within the effective operating range of the fine drive. For example, the coarse drive can be moved away from or toward the surface until the stored contact position is midway between the minimum and maximum ranges of the fine drive. In this state, the fine drive is again used to return the tip 106 to the contact position. Optionally, a small negative or positive offset can be used to increase or decrease the final distance between the tip 106 and the surface. Alternatively or additionally, the same stopping criteria can be used at this stage to prevent unnecessary contact with particles, etc. The aforementioned process allows the tip 106 to be completely or at least partially automatically seated on the sample surface 138 or previously identified particles 132, accelerating the preparation phase for manipulating the surface 138 or particles 132. Thus, it greatly simplifies the actuation operations that are usually performed under operator control. At the same time, it provides a high degree of safety due to the real-time monitoring of the relevant stopping criteria, thereby avoiding unwanted hard contact points between the tip 106 and the sample 102. 36 illustrates different images provided by an apparatus for assisting a user during particle removal according to another embodiment. As previously mentioned, the image record can be provided by a scanning electron microscope 128 or similar imaging device. In the embodiment described, the image record can be provided in real time, that is, immediately upon activation of the nanomanipulator 104. This generally provides good control and feedback to the operator, for example, during particle removal processing. However, when manipulating very small surface structures of sample 102 or removing very small particles 1232, tip 106 may obscure the operator's view. This is depicted in image 1260 provided by a scanning electron microscope according to Figures 36a and 36b. Note that structural features 1292 and 1294 (e.g., line features) and particle 1232 located on the surface of sample 102 are smaller in width or diameter than tip 106. Furthermore, as previously mentioned, tip 106's actual contact point 1268 (i.e., actual apex 168) may not be located at its outer edge (e.g., the left point in Figure 36), but somewhere below tip 106. In other words, the operator may not be able to see the portion of surface 138 that is actually in contact with tip 106. Furthermore, as the operator moves tip 106 to remove particle 1232, particle 1232 itself may be partially or completely obscured by tip 106, as shown in Figure 36b. To provide the operator with better control during operation, an improved image 1260 ′ may be displayed on a user interface (eg, HMI 142 ). In one embodiment, first marker 1268' is shown at the location of a previously determined contact point 1268, for example, using the method described above for determining vertex 168. As tip 106 moves within the field of view corresponding to image 1260, the position of first marker 1268' moves in a corresponding direction to consistently mark contact point 1268, as shown in Figures 36a) to d). In the same or alternative embodiments, edge detection, contrast analysis, or similar image processing algorithms can be used to detect the outer edges (i.e., outlines) or shapes (i.e., areas) of features 1292, 1294, and / or particles 1232 before tip 106 is moved, i.e., before tip 106 obscures features 1292, 1294, and / or particles 1232. Then, as tip 106 moves over features 1292, 1294, and / or particles 1232, the previously detected edges or outlines are indicated by distinctive markers 1232', 1292', and 1294', as shown in FIG. 36c). Alternatively, an image of the entire surface can be stored (e.g., buffered) and used to show the entire surface physically obscured by tip 106, as shown in FIG. 36d). This can be achieved by merging a segment of the stored image captured before the tip is moved over the corresponding segment with the live image. In this case, the position of the tip 106 (i.e., the area covered by the image) can be indicated by a third marking 1206', as also shown in Figure 36d). Optionally, the user can select between the output image 1260' according to Figure 36c) or the output image 1260" according to Figure 36d). Although the present invention has been described based on exemplary embodiments, the present invention can be modified in various ways. 1: Curve 2: Curve 3: Line 4: Line 5: Line 100: Device 102: Sample 104: Nanomanipulator (Atomic Force Microscope) 106: Measuring tip 108: Extension arm 110: Positioning unit 112: End / base point 114: End 116: Housing 118: Pump 120: Sample carrier 122: Mounting base 124: Positioning unit 126: Sample carrier assembly 128: Particle beam column / electron column 130: Particle beam 132: Defect (particle) 134: Process gas supply unit 136: Process gas 138: Surface 140: Control device 142: Human machine interface 144: Display device 146: Keyboard 148: Mouse pointer 150: Deflection detection device / light pointer device 152: Laser source 154: Photodetector 156: Laser beam 158: Laser beam 160: Image 162: Structure / absorber structure 164: Groove 166: Substrate 168: Actual vertex 170: Surface Vertex 172: Surface 174: Surface 176: Region 178: Trajectory 180: Line 182: Trajectory 184: Line 186: Approach Curve 186': Approach Curve 186": Approach Curve 188: Region 188': Region 188": Region 190: Material 190': Material 190": Material 200: Indentation 204: Movement 206: Movement 208: Step 208': Step 210: Lateral Movement 212: Lift Movement 214: Lifting movement / movement / curved trajectory 215: trajectory 260: image 260': image 260": image 302: sample 360: image 362: structure 364: groove 402: sample 438: surface 502: sample 532: particle 538: surface 602: sample 632: particle 702: sample 732: particle 732': image 760: image 760': particle 802: particle 832: particle 860: image 860': nanostructure 900: nanostructure 902: surface 904: actual vertex 906: Raster scan data 908: Point 910: Point 912: Image 914: Apparent apex 916: Nanostructure 918: Tip 1000: System 1001: Extended arm deflection system / extended arm deflection detection system 1002: Frequency conversion control system 1003: Amplitude control system 1004: Phase detector 1005: First feedback unit / integrator 1006: Controllable oscillator 1007: Amplitude detector 1008: Second feedback unit / Proportional-Integral (PI) controller 1009: Multiplier 1010: Excitation signal (resonant drive signal) 1011: Deflection signal 1012: Lateral signal 1013: Phase signal1014: Frequency control signal 1015: Phase setting value 1016: Amplitude signal 1017: Amplitude setting value 1018: Oscillator output signal 1019: Amplitude feedback signal 1100: Beam deflection system 1102: Specimen 1106: Probe 1110: Actuator unit (piezoelectric element) 1152: Light source 1154: Photodiode 1232: Particle 1232': Marker (particle indicator) 1206': Marker (tip indicator) 1260: Image 1260': Image 1260": Image 1268: Contact point 1268': Marker (contact point indicator) 1292: Structural feature 1292': Marker (structural indicator) 1294: Structural feature 1294': Marker (structural indicator) A: Distance A 1: Distance A 2: Distance A 3: Distance A S :Distance A S ': Distance B: Bend B1: Brightness B2: Brightness bl: Area br: Area C1: Distance C2: Distance C3: Distance D: Deflection D 1: Level D 2: Level D 3: Degree / Deflection D 3”: Level D S :Deflection D S ': deflection E: plane G: dimension H: height IV-IV: line Px: position Px 0:PositionPy:PositionPy 0: Position Pz: Position R: Rotation / Twist S: Line of sight S1: Method step S1': Method step S1": Method step S1': Method step S1': Method step S1'": Method step S1'": Method step S2: Method step S2': Method step S2': Method step S2': Method step S2': Method step S2': Method step S2': Method step S2': Method step S2': Method step S2': Method step S2': Method step S20: Step S21: Step S22: Step S23: Step S24: Step S25: Step S26: Step S3: Method step S3': Method step S3': Method step S3': Method step S3': Method step S3': Method step S4: Method step S4': Method step S4': Method step S4': Method step S4': Method step S4': Method step S4': Method step S5: Method step S5': Method step S5': Method step S5': Method step S6: Method step S6': Method step S6': Method step S6': Method step T: Remove trajectory u l :Area u r :Area x 1: Position x 2: Position x A :Position x E :Position x' E :Position x G :Position x N :Position x P :Position y 1: Position y 1': position y 2: Position y 2': Position y G :Position y P :Position Z 1:z-position Z 2:z-position Z 3:z-position Z 4:z-position Z 5:z-position Z 6:z-position Z 7:z-position Z 8:z-position Z 9:z-position Z 10 :z-position ΔB:brightness change ΔF:focus change ΔF 1: Focus change ΔF S : critical value Δl 1: Distance Δl 2: Distance Δx: Distance / Offset Δy: Offset Δz 1: Distance Δz 2: Distance Δz 3: Distance Δz 4: Distance Δz 5: Distance Δz 6: Distance Δz 7: Distance Δz 8: Distance Δz 9: Distance FIG1 shows an apparatus for analyzing and / or processing a sample according to one embodiment; FIG. 2 shows an enlarged portion of the apparatus of FIG. 1 incorporating a light director device according to one embodiment. Figure 3 shows an image of a portion of a sample processed by the apparatus of Figure 1 according to an embodiment; FIG. 4 is a cross-sectional view taken along line IV-IV in FIG. 3 . FIG. 5 shows an enlarged view of a measuring tip of the apparatus in FIG. 1 according to an embodiment. FIG6 shows an image of a sample and a portion of the measurement tip from FIG5 according to one embodiment; FIG. 7 shows a view similar to FIG. 6 , wherein the measuring tip has left a first track in the test area of ​​the sample according to an embodiment; FIG8 illustrates a view similar to FIG7 , wherein a first straight line has been fitted to the first trajectory, according to one embodiment; 9 shows a view similar to FIG. 8 , wherein the measuring tip has left a second track in the test area of ​​the sample and a second straight line has been fitted to the second track, according to an embodiment; FIG10 illustrates an approach curve that plots the deflection of the free end of the extension arm from the apparatus of FIG1 as a function of the distance from the base end of the extension arm, according to one embodiment; FIG11 shows an image of a portion of a sample having three test areas according to one embodiment; FIG12 illustrates a diagram similar to FIG10 , showing three approximation curves for the three test areas in FIG11 , according to one embodiment; FIG13 illustrates automatic positioning of a measurement tip at a predetermined working distance from a sample according to one embodiment; FIG14 illustrates a fully automated iterative particle removal process according to one embodiment; FIG. 15 a illustrates different lateral distances applied during the fully automated iterative particle removal process from FIG. 14 , according to one embodiment; FIG15 b illustrates different z-distances applied during the fully automated iterative particle removal process from FIG14 according to one embodiment; 16a to 16c illustrate another fully automated iterative particle removal process according to one embodiment; FIG17 illustrates a first variant of a process according to an embodiment, in which a check is performed as to whether particles adhere to the measuring tip; FIG18 illustrates a second variant of the process according to an embodiment, in which a check is performed as to whether particles adhere to the measuring tip; FIG. 19 shows brightness changes due to particles adhering to the measurement tip in a second variation of the process from FIG. 18 according to an embodiment; FIG20 illustrates a third variant of the process according to an embodiment, in which a check is performed to see whether particles adhere to the measuring tip; FIG21 illustrates a fourth variation of the process according to an embodiment, wherein an actuator checks whether particles adhere to a measuring tip; FIG22 illustrates a flow chart of a computer-implemented method for processing a sample using the apparatus from FIG1 according to one embodiment; FIG23 illustrates a flow chart of a computer-implemented method for processing a sample using the apparatus from FIG1 according to another embodiment; FIG24 illustrates a flow chart of a computer-implemented method for processing a sample using the apparatus from FIG1 according to another embodiment; FIG25 illustrates a flow chart of a computer-implemented method for processing a sample using the apparatus from FIG1 according to another embodiment; FIG. 26 illustrates a computer-implemented method for determining an actual vertex of a measuring tip according to one embodiment, wherein FIG. 26 shows a sample having a nanostructure and a measuring tip for determining an actual vertex of the measuring tip; FIG. 27 shows a recorded image according to one embodiment, in which the sample with the nanostructure and the measurement tip from FIG. 26 are captured; FIG28 illustrates another embodiment of a nanostructure for determining the actual apex of a measurement tip; FIG29 illustrates a flow chart of a computer-implemented method for processing a sample using the apparatus from FIG1 according to another embodiment; FIG30 is a schematic diagram illustrating a system for detecting a frequency offset of a driving signal according to another embodiment; FIG31 shows a schematic diagram of a beam deflection system; FIG32 shows the resonance curves of the tip in vacuum and air, respectively; FIG33 shows a method for detecting the interaction between the tip and the sample based on tracking the amplitude signal; FIG34 illustrates a method for detecting the interaction between a tip and a sample based on tracking a frequency signal according to another embodiment; FIG35 illustrates a flow chart of a computer-implemented method for seating a probe of a nanomanipulator on a sample using the system from FIG30 according to one embodiment; and FIG36 shows different images provided by a device for assisting a user during particle removal.

Claims

1. A method for placing a tip (106) of a probe (1106) of a nanomanipulator (104) onto a sample (102, 1102), particularly in a vacuum, the probe (1106) comprising an extension arm (108) and the tip (106) attached thereto, the nanomanipulator (104) further comprising an excitation unit (1110) to which the probe (1106) is mechanically coupled, the method comprising the steps of: - when the tip (106) is not in contact with the sample (102), oscillating the probe (1106) by providing a resonant drive signal (1010) to the excitation unit (1110); - During a first approach phase, reduce a first distance along a z-direction between the tip (106) and the sample (102) until at least one of a first set of stop conditions is met, wherein the first set of stop conditions includes detecting a shift in the frequency of the resonant drive signal (1010) used during the first approach phase; and - terminate the first approach phase when the at least one of the first stop conditions is met, and deactivate the resonant drive signal (1010).

2. The method of claim 1 further comprises: - further reducing the first distance during a second approach phase until at least one of a second set of stopping conditions is met, wherein the second set of stopping conditions includes detecting a deflection of the extendable arm (108); and - terminating the second approach phase at a contact position when the at least one of the second set of stopping conditions is met.

3. The method of claim 2, wherein a combination of a coarse drive and a fine drive is used along the z-direction to control the position of at least one of the probe (1106) or the sample (102), the method further comprising performing a third approach phase comprising: - increasing the first distance by operating the fine drive to move the tip (106) from the contact position to a partially retracted position; and - decreasing or increasing the first distance by operating the coarse drive based on a second distance along the z-direction between the contact position and the partially retracted position; and - decreasing the first distance by operating the fine drive to return the tip (106) to the contact position or to a predetermined position at a third distance along the z-direction from the contact position.

4. The method of any one of claims 1 to 3 further comprises: - determining at least one parameter of a resonant characteristic of the probe (1106) when the tip (106) is not in contact with the sample (102), the at least one parameter comprising at least one of a resonant frequency of the probe (1106), a Q value of the probe (1106), and a phase angle between the resonant drive signal (1010) and a detected deflection signal (1011) related to the oscillation of the probe (1106).

5. The method of any one of claims 1 to 3, wherein the first set of stopping conditions includes at least one of the following conditions: - a frequency control signal (1014) indicating a shift in the frequency of the resonant drive signal (1010) exceeds a first threshold; - a frequency control signal (1014) indicating a shift in the frequency of the resonant drive signal (1010) is below a second threshold; - an amplitude feedback signal (1019) for amplitude control of the resonant drive signal (1010) exceeds a third threshold; - an amplitude feedback signal (1019) for amplitude control of the resonant drive signal (1010) is below a fourth threshold; - a phase signal (1013) indicating the relationship between the resonant drive signal (1010) and the oscillation detected by the probe (1106) exceeds a fifth threshold and / or is below a sixth threshold; and / or - a driving speed along the z-direction exceeds a seventh threshold and / or is below an eighth threshold.

6. The method of claim 5, wherein the placement of the probe (1106) is terminated in the first approach phase when at least one of the following conditions is met: - the frequency control signal (1014) is below the second threshold; - the amplitude feedback signal (1019) exceeds the third threshold; - the phase signal (1013) exceeds the fifth threshold and / or is below the sixth threshold; and / or - the drive speed exceeds the seventh threshold and / or is below the eighth threshold.

7. The method of any one of claims 2 to 3, wherein the second set of stopping conditions further comprises: - indicating that a first deflection signal (DFL) of a deflection of the probe (1106) along the z-direction exceeds a ninth critical value; - indicating that a second deflection signal (LAT) of a lateral deflection of the probe (1106) exceeds a tenth critical value; - indicating that a summation signal (SUM) of a combination of deflections of the probe (1106) exceeds an eleventh critical value; and / or - a driving speed along the z-direction exceeds a twelfth critical value and / or is lower than a thirteenth critical value.

8. The method as claimed in claim 2 or 3, wherein the placement of the probe (1106) is terminated in the second approach phase when at least one of the following conditions is met: - the driving speed along the z-direction exceeds the twelfth critical value and / or is below the thirteenth critical value.

9. The method of any one of claims 1 to 3 further comprises: - capturing a first image (1260) of a surface (138) of the sample (102), the first image comprising at least one segment not obscured by the tip (106); - generating a second image (1260', 1260”) comprising at least one segment obscured by the tip (106) and at least one mark (1206', 1232', 1268', 1292', 1294'), the at least one mark being disposed in the obscured segment and indicating the location of at least one hidden element; and - displaying the second image (1260', 1260”) to an operator of the nanomanipulator (104) on a user interface during manipulation of the sample (102).

10. The method of claim 9, wherein the at least one marker (1206', 1232', 1268', 1292', 1294') comprises at least one of: - a contact point indicator (1268') indicating the location of a contact point (1268) between the probe (106) and the sample (102); - a structure indicator (1232', 1292', 1294') indicating an edge or region of a surface feature (1292, 1294) or a particle (1232) on the surface (138) of the sample (102); and - a tip indicator (1206') indicating a profile of the tip (106), wherein the tip (106) is replaced in the second image by a corresponding segment of the surface (138) of the sample (102) obtained from the first image (1260).

11. An apparatus for processing a sample (102) using a nanomanipulator (104), comprising: - a sample stage (120) for holding the sample (102); - the nanomanipulator (104) including a positioning unit (110) and an excitation unit (1110), the positioning unit (110) being configured to move a probe (1106) including an extension arm (108) and a tip (106) attached thereto, the excitation unit (1110) being configured to oscillate the probe (1106) based on a drive signal; - an extension arm deflection detection system (1001) configured to detect a plurality of deflections of the extension arm (108); - A control loop circuit configured to track a signal relationship between an oscillation of the extender arm (108) detected by the extender arm detection system and a drive signal provided to the excitation unit (1110); and - at least one control unit configured to perform the following steps: - using the excitation unit (1110), driving the probe (1106) with a resonant drive signal (1010) provided by the control loop circuit when the tip (106) is not in contact with the sample (102); - by means of the positioning unit, reducing a first distance in a z-direction between the tip (106) and the sample (102) during a first approach phase until at least one of a first set of stop conditions is met, wherein the first set of stop conditions includes detecting a shift in the frequency of the resonant drive signal (1010) used during the first approach phase; and - terminating the first approach phase when the at least one of the first stop conditions is met, and deactivating the resonant drive signal (1010).

12. The device of claim 11, wherein the control loop circuitry comprises: - a frequency control system (1002) configured to provide a first output signal based on a phase and a phase setpoint (1015) of a detected oscillation of the extender arm (108); - an amplitude control system (1003) configured to provide a second output signal based on an amplitude and an amplitude setpoint (1017) of the detected oscillation of the extender arm (108); and - a multiplier (1009) configured to multiply the first output signal provided by the frequency control system (1002) by the second output signal provided by the amplitude control system (1003), and to provide the multiplied signal as a resonant drive signal (1010) to the excitation unit (1110).

13. The device as claimed in claim 12, wherein the frequency control system (1002) includes a phase detector (1004) for providing a phase signal (1013), an integrator (1005) for providing a frequency control signal (1014), and a controllable oscillator (1006) for providing an oscillator output signal (1018).

14. The device as claimed in claim 12 or 13, wherein the amplitude control system (1003) includes an amplitude detector (1007) for providing an amplitude signal (1016) and a PI controller (1008) for providing an amplitude feedback signal (1019).

15. A computer program product comprising a plurality of instructions which, when executed by at least one computer, cause the computer to perform the method described in any one of claims 1 to 11.

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