Method of mapping one or more features on or below a substrate surface using a scanning probe microscopy device.

Abstract

The present document relates to a method of mapping one or more features on or below a substrate surface of a substrate using a scanning probe microscopy device. The scanning probe microscopy device comprises a scan head comprising a cantilever and a probe tip for being brought into contact with the substrate surface. The scan head cooperates with a substrate carrier for moving the probe tip relative to the substrate surface for obtaining measurement data, the substrate carrier being configured for supporting the substrate. The method comprises mapping the one or more features by moving the probe tip relative to the substrate surface and bringing the probe in contact with the substrate surface continuously or intermittently for taking measurements at the substrate surface. Prior to the step of mapping, the method further comprises obtaining, for each pixel of a plurality of pixels wherein the measurements are to be taken, a pixel size associated with a predetermined measurement resolution. The pixel size defines a measurement area for the probe tip for taking said measurements at each pixel at the substrate surface. The method then involves applying, for performing the step of mapping, a probe comprising a probe tip having an apex including a rounded shape, the rounded shape having a radius of curvature such as to yield, in contact with the substrate surface, a contact area of a size substantially similar to said measurement area.

Description

[0001] P137502PC00

[0002] Title: Method of mapping one or more features on or below a substrate surface using a scanning probe microscopy device.

[0003] Field of the invention

[0004] The present invention is directed at a method of mapping one or more features on or below a substrate surface of a substrate using a scanning probe microscopy device, which comprises a scan head comprising a cantilever and a probe tip for being brought into contact with the substrate surface. The scan head cooperates with a substrate carrier for moving the probe tip relative to the substrate surface for obtaining measurement data. The method involves moving the probe tip relative to the substrate surface and bringing the probe in contact with the substrate surface continuously or intermittently for taking measurements at the substrate surface.

[0005] Background

[0006] Scanning probe microscopy is a powerful nanotechnological tool that allows for providing detailed topographical and subsurface data with nanometer resolution. This has applications in the semiconductor industry, because this capability enables the performance of defect analysis and surface characterization, which are essential for the development of increasingly smaller and more efficient semiconductor devices. Further examples of the applications of scanning probe microscopy include cell and biomolecule imaging and nanotoxicology, because the precise measuring capability of scanning probe microscopy enables visualization of biological structures at nanoscales, and enables characterization of how nanoparticles interact with cells and biological tissue.

[0007] However, the need for precise movement of the probe and precise measurement of samples makes scanning of a substrate surface a time-consuming process, especially when analyzing large areas. This imposes a limit on the technique’s throughput that is especially adverse in industrial applications.

[0008] Moreover, during scanning of the probe tip across the surface of a substrate in contact, non-contact or intermittent contact mode, sliding of the probe tip in contact with the surface or impact on the probe tip when brought into contact with the substrate surface, causes damage to the probe tip continuously. As a consequence the probe has to be replaced frequently due to wear. This takes time, and in addition, each probe replacement requires recalibration of the device and adjustment of settings, which further substantially slows down the process. This also adversely affects the throughput when scanning a substrate surface using a scanning probe microscopy device, thereby providing a challenge to industrialization of the measurement technique.

[0009] Summary of the invention

[0010] It is an object of the present invention to provide a method which overcomes the abovementioned drawbacks and which provides a faster and more optimized method of mapping a substrate surface using a scanning probe microscopy device, which lowers the bar to industrialization.

[0011] To this end, there is provided herewith a method

[0012] of mapping one or more features on or below a substrate surface of a substrate using a scanning probe microscopy device, wherein the scanning probe microscopy device comprises a scan head comprising a cantilever and a probe tip for being brought into contact with the substrate surface, wherein the scan head cooperates with a substrate carrier for moving the probe tip relative to the substrate surface for obtaining measurement data, the substrate carrier being configured for supporting the substrate, wherein the method comprises: mapping the one or more features by moving the probe tip relative to the substrate surface and bringing the probe in contact with the substrate surface continuously or intermittently for taking measurements at the substrate surface; wherein prior to the step of mapping, the method comprises: obtaining, for each pixel of a plurality of pixels wherein the measurements are to be taken, a pixel size associated with a predetermined measurement resolution, wherein the pixel size defines a measurement area for the probe tip for taking said measurements at each pixel at the substrate surface, applying, for performing the step of mapping, a probe comprising a probe tip having an apex including a rounded shape, the rounded shape having a radius of curvature such as to yield, in contact with the substrate surface, a contact area of a size substantially similar to said measurement area. In research, the high precision of probe movement and measurement in scanning probe microscopy is essential, and scanning in these settings is typically performed with ultra-fine tips. However, these ultra-fine tips necessarily yield ultra-local information about the sample. The invention is based on the realization that in industrial settings, the need for highly resolved sample information is traded off for the need for high throughput. The present invention substantially increases throughput by sacrificing a degree of measurement resolution that is unnecessary for industrial applications. By performing the step of mapping with a probe having a probe tip of which the rounded shape at the apex yields a contact area substantially similar in size to the measurement area, the invention effectively takes an average measurement for each pixel in an area where multiple pixels of an ultra-fine tip would be located. The measurement area, defined by the pixel size, is the area to be covered by the probe tip in the measurements to be taken for each individual pixel. This larger measurement area, corresponding to the pixel size, is covered in a single measurement by the probe used in the invention. This reduces the amount of measurements to be taken and allows the substrate surface to be scanned much more quickly, while still covering the full surface. This large speed increase substantially improves throughput and thereby makes the method much more suitable for industrial applications. Average measurements over larger measurement areas also reduce the amount of random measurement noise, as the fluctuations in positive and negative directions cancel each other out. Additionally, due to the small size of ultra-fine tips, they strongly interact with small imperfections on the substrate surface. For example, the probe easily gets stuck in small cavities or at small protruding features. This makes it necessary to free the probe each time before it can continue traversing the substrate surface. Also, these interactions, caused by the small relative size of the probe tips compared to the imperfections, introduce large disturbances and noise components in the measurement signals. This complicates data interpretation and makes it necessary to perform additional data processing. The rounded shape used in the invention is too large to interact with these small imperfections and will therefore easily slide over them. The scanning speed is therefore increased even further by the invention. Moreover, using a probe with a rounded shape according to the invention substantially reduces the impact of such interactions on the measurement signal. The invention therefore improves the measurement quality and measurement stability of the method. Moreover, the present invention advantageously distributes the impact to the probe tip upon making contact with the substrate surface across said contact area. The damage caused to the probe tip by the probe being brought in contact with the substrate surface is thereby reduced, improving the lifetime of the probe. This increases the lifetime of probes and reduces the frequency with which the probe has to be replaced. The method according to the invention thereby further improves the industrializability of the method. A further advantage of the invention is that the larger contact area of the rounded shape of the probe simultaneously distributes the impact over a larger area of the substrate surface. Potential damage to small or fragile features is thereby also reduced in the invention. Furthermore, the present invention enables a substrate surface to be divided into different regions, in which some regions contain smaller features and other regions contain larger features. The regions containing the smaller features would require a larger measurement resolution for them to be properly mapped, while the larger features would not require an equally high resolution. The invention therefore enables scanning of such substrate surfaces in a more targeted manner that optimizes between scanning speed and measurement resolution.

[0013] In accordance with some embodiments of the invention, the step of obtaining a pixel size comprises defining a measurement range on the substrate surface for confining the moving of the probe tip relative to the substrate surface, wherein the measurement range and the predefined measurement resolution set an amount of pixels of the plurality of pixels. The measurement range may be defined based on the substrate to be measured. For example an entire surface may be desired to be scanned. If this range is fixed, then by varying the measurement resolution, the amount of pixels can be varied before carrying out a measurement, allowing the user to influence the speed with which the measurement is carried out. Alternatively, a user may wish to focus on a specific part of a surface with a fixed measurement resolution. The user may then for example minimize the measurement range to a region of interest and thereby influence the speed of the measurement. These embodiments therefore advantageously provide more freedom in defining the measurement parameters of the method. In accordance with some embodiments of the invention, one of: the step of obtaining a pixel size is performed, such that the measurement range is completely covered by the plurality of pixels, such that each measurement area is positioned mutually adjacent in the measurement range; or the step of obtaining a pixel size further comprises defining a pixel spacing, wherein the plurality of pixels and the pixel spacing are arranged across the measurement range in an alternating order. It may be critical that the entire substrate surface is scanned, for example because critical features are distributed over the entire surface. However, in alternative embodiments, such critical features may only be located in certain regions of the substrate surface. In that case, it would be advantageous to define a pixel spacing that ensures that those relevant regions are scanned, while non-critical regions would not be scanned. These embodiments therefore allow for focused, targeted sampling, which further reduces the time needed for the scanning process.

[0014] In accordance with some embodiments of the invention, prior to the step of mapping, the method comprises selecting the probe applied for performing the step of mapping from a plurality of probes, wherein the probe tip of each of the plurality of probes comprises an apex having a rounded shape, wherein the rounded shape of the apex of each of the plurality of probes has a radius of curvature such as to yield, in contact with the substrate surface, a mutually different contact area. A number of probes that have a rounded shape at the probe tip apex may be available, each of which has a different radius of curvature. The user may then choose the probe that has the most suitable shape for the specific requirements of the measurement to be performed. For a given measurement resolution a probe with a larger radius of curvature will allow a scan to be performed more quickly, and the larger contact area of such a probe will allow it to last for a longer period of time without the need for replacement. The method in accordance with these embodiments therefore allow for a more precise tailoring of the scanning probe microscopy device to the specific needs of a user by offering control of the radius of curvature of the rounded shape.

[0015] In accordance with some embodiments of the invention, the step of selecting is performed, such as to minimize a deviation from the measurement area by the contact area of the rounded shape and the substrate surface. Between all available probes, an optimum may be found between an as fast as possible scan and an as high as possible measurement resolution. Typically, a user specifies a desired measurement resolution beforehand, defining a pixel size for the measurement. Between any available probes, the one yielding a contact area with the substrate surface that approximates the pixel size as closely as possible would be the one that is closest to said optimum between scan speed and measurement resolution.

[0016] In accordance with some embodiments of the invention, prior to the step of mapping, the method comprises replacing a probe preinstalled on the scan head with the selected probe. Before performing a measurement of a substrate surface, a probe may be preinstalled on the scan head. This preinstalled probe may still be present from a previously performed measurement and may be less suitable for the specific requirements of the measurement to be presently performed. The radius of curvature of a rounded shape on the tip apex may for example be too small, or the tip apex may not comprise such a rounded shape at all and may instead be an ultra-fine tip. In alternative embodiments, no probe may be preinstalled on the scan head. In those embodiments, the desired probe may be directly installed onto the scan head prior to performing a measurement.

[0017] In accordance with some embodiments of the invention, a deviation from the measurement area by the contact area of the rounded shape and the substrate surface is smaller than 20% of the measurement area, preferably smaller than 10% of the measurement area, more preferably smaller than 5% of the measurement area. The invention over time is able to sufficiently reduce the damage to the probe tip caused by making contact between the probe tip and the substrate surface even if the measurement area and the contact area do not match exactly. By approximating the measurement area to within the above percentages, the contact area is large enough to increase the lifetime of a probe significantly. The closer the contact area matches the measurement area, the greater the gain in the probe lifetime.

[0018] In accordance with some embodiments of the invention, for performing the step of mapping of one or more features below the substrate surface, the method comprises applying an acoustic vibration to the probe or to the substrate, the acoustic vibration comprising signal components such as to establish at least an output signal portion having an amplitude and a frequency that are within a sensitivity range of the probe. The method according to the invention is suitable for being applied for the measurement of subsurface features, such as buried interfaces of layers, or subsurface defects or inclusions. These embodiments of the invention therefore are able to gain the advantages of longer probe lifetime and better industrializability while remaining versatile enough to be applied for the measurement of subsurface features.

[0019] In accordance with some embodiments of the invention, the signal components include at least a first signal component and a second signal component, wherein at least one of: the first signal component or the second signal component comprises a frequency below 100 MHz; and the first signal component or the second signal component comprises a frequency above 100 MHz; wherein the frequency of the output signal portion is equal to a difference between the frequency of the first signal component and the frequency of the second signal component. In either case, the probe will then detect a reflected output signal component that has a frequency equal to the difference between two signal components of the applied acoustic vibration. The applied acoustic vibration may have high frequency signal components (such as above 100 MHz). As the vibrations propagates below the substrate surface through the sample, it may be scattered by features below the substrate surface. In that case, the probe will detect such features by measuring back-scattered acoustic signals. Alternatively, the applied acoustic vibration may have lower frequency signal components (such as below 100 MHz). In that case, features below the substrate surface are detected based on certain material properties, such as stiffness, viscoelasticity or density. Changes in these properties can correspond to changes in the speed or damping of the vibration, which changes may be detected for measuring of features below the substrate surface.

[0020] In accordance with some embodiments of the invention, for performing the step of mapping of one or more features on the substrate surface, the method comprises sensing a deflection of the probe tip by a feature on the substrate surface, wherein the method further comprises correcting for the deflection of the probe tip, for determining a dimension of the feature, wherein at least one of: the step of correcting is performed based on a deflection signal of the scanning probe microscopy device; and the step of correcting is performed based on a correction signal generated by a controller of the scanning probe microscopy device, wherein the correction signal is based on a difference between the deflection signal and a predefined setpoint. The step of correcting is more typically performed based on the correction signal from the controller, because it allows for real-time adjustments to maintain consistent imaging conditions with higher accuracy and stability in the measurements. But the step of correcting may alternatively be performed based on the deflection signal directly. This can make the process more efficient by reducing the need for additional processing steps, as it leverages the raw deflection data from the probe tip interaction with the surface. Alternative embodiments employ a combined approach where the deflection signal is used directly on certain parts of the substrate surface, while the correction signal is used in other areas. This provides flexibility in adapting to different surface conditions and optimizes between efficiency and accuracy depending on the specific features of the substrate being analyzed.

[0021] In accordance with some embodiments of the invention, the step of mapping is performed using a probe having a rounded shape including a radius of curvature such that during the step of mapping, the probe is configured for making contact with a sidewall of a feature on the substrate surface at a contact point on the rounded shape, the contact point being positioned below a center of the rounded shape. For example, when the probe comes into contact with a sidewall during scanning in contact mode, the sidewall will exert a force on the probe having an upward component and a backward component. The magnitude of both components depends on the angle of the probe at the contact point. When this contact point is positioned below the center of the rounded shape, as defined by the radius of curvature, the upward component of the force will provide the probe with upward momentum. This facilitates the upward movement of the probe that is necessary for passing over the feature, thereby further improving the speed with which the substrate surface can be scanned. The larger the height difference between the center of the rounded shape and the contact point above it, the greater this advantage. Therefore, these embodiments are especially advantageous for being applied to scan substrate surfaces that contain low aspect ratio features, because such features are more likely to make contact with the probe at a lower contact point.

[0022] In accordance with some embodiments of the invention, the rounded shape is one of a group comprising: spherical shapes, hemispherical shapes, ellipsoidal shapes, paraboloidal shapes, and ovoidal shapes. The rounded shape may have any of the abovementioned rounded shapes, each of which may better conform to a user’s specific requirements. For example, the different shapes will form different arcs, even with equal radii of curvature. When approaching a sidewall of a low aspect ratio feature, a rounded shape that collides with the top of the sidewall will be deflected differently based on the angle with which the collision occurs and the point of contact on the sidewall. The higher the point of contact, and the more shallow the angle, the easier the probe is able to pass over the sidewall. Conversely, the lower the point of contact and the steeper the angle, the more the probe will be blocked by the sidewall. The probe in that case will have to move up from the substrate surface by a larger distance before the scan of the substrate surface can be resumed.

[0023] In accordance with some embodiments of the invention, after performing the step of mapping of one or more features on the substrate surface using a probe comprising a probe tip having an apex including an at least partially spherical rounded shape, the method further comprises receiving the measurement data, wherein the method further comprises processing of the measurement data for generating a model of the one or more features on the substrate surface, wherein the step of processing comprises deconvolving the measurement data with probe tip shape data, the probe tip shape data being associated with the at least partially spherical rounded shape of the apex, wherein said deconvolving of the measurement data with the probe tip shape data yields surface profile data associated with the one or more features on the substrate surface. In an implementation where the probe tip is a spherical tip positioned at the end of the probe, the probe tip reduces the complexity of deconvolution during or after surface scanning. When the probe tip is spherical, it maintains a constant radius. The midpoint can coincide with the longitudinal axis through the probe tip, making the spherical probe tip rotationally symmetric around this axis with a consistent radius. Since the radius of the probe tip remains constant, angling or deformation of the probe can be conveniently adjusted and corrected. For instance, if the probe tip is angled relative to its original position, the projected width and height of the spherical tip on the sample remain unchanged. However, in alternative embodiments the tip may also be partially spherical - e.g. hemispherical. The above described advantage is achieved by the fact that the part of the probe tip that makes contact with and is deflected by the features on the substrate, is the spherical part of the probe tip. This differs from non-spherical probe tips, where angling or rotation typically affects the projection of width and / or height on the sample surface, potentially leading to incorrect measurements, artifacts, or additional errors that require correction. A spherical probe tip at the end of the probe alleviates these issues by reducing the complexity of deconvolution during or after scanning. Specifically, the spherical shape of the probe tip makes deconvolution independent of the probe's angle relative to the sample surface, thereby decreasing complexity and offering a distinct advantage during deconvolution. This reduction in processing complexity is especially advantageous for high-throughput scanning probe microscopy applications, such as those in industrial environments.

[0024] In accordance with a second aspect of the invention, there is provided herewith a method of manufacturing a probe for use in a method according to any one or more of the preceding claims, the probe being suitable for mapping one or more features on or below a substrate surface of a substrate using a scanning probe microscopy device, the method comprising manufacturing a cantilever of the probe and a probe tip for being brought into contact with the substrate surface, said manufacturing comprising the steps of: obtaining a pixel size associated with a predetermined measurement resolution, wherein the pixel size defines a measurement area for the probe tip for taking measurements at a pixel on a surface of a substrate supported by the scanning probe microscopy device, and providing the probe having a rounded shape at an apex of the probe tip, said providing being controlled such that the rounded shape has a radius of curvature for yielding, in contact with the substrate surface, a contact area of a size substantially similar to said measurement area.

[0025] The invention makes the use of scanning probe microscopy for mapping features on or below a substrate surface much more suitable for industrial settings, by sacrificing an unnecessary degree of measurement resolution for a high gain in measurement speed, which allows much higher throughputs to be achieved. By obtaining a pixel size associated with a predetermined measurement resolution, and controlling the radius of curvature of the rounded shape at the apex of the probe tip, the method according to the second aspect of the invention provides a probe yielding a contact area between the rounded shape and the substrate surface that is substantially similar in size to the measurement area. The probe manufactured by the method according to the second aspect of the invention is therefore specifically tailored to the obtained pixel size. Advantageously, this allows a user to obtain probes that fulfill specific size and shape requirements in industrial settings, which are not yet available. A user may for example determine that the probes already at his disposal have probe tips that are too small in size and strongly interact with small imperfections on the substrate surface. These interactions, caused by the small relative size of the probe tips compared to the imperfections, introduce large disturbances and noise components in the measurement signals. This complicates data interpretation and makes it necessary to perform additional data processing. By providing a probe with a rounded shape that yields a contact area substantially larger than these imperfections, the method according to the present invention improves the measurement stability of the technique. This added versatility therefore further increases the suitability of scanning probe microscopy in industrial settings. Furthermore, by tailoring the rounded shape to the specific requirements of the user, the method according to the second aspect of the invention provides a high degree of control over the probe tip shape and optimizes the trade-off between measurement accuracy and high throughput, and thereby facilitates maximization of the reliability of scanning probe microscopy in industrial settings. The probe may for example be manufactured in the method according to the second aspect of the invention using focused ion beam milling, where a beam of ions is precisely directed to sculpt the apex of the probe into the rounded shape. Alternatively, the probe may for example also be manufactured using chemical vapor deposition, where the rounded shape is grown directly on the probe tip apex by introducing specific precursor gases that decompose and deposit material onto the probe, thereby forming the rounded shape. These techniques allow for precise control over the curvature and size of the rounded shape.

[0026] In accordance with a third aspect of the invention, there is provided herewith a method of mapping one or more features on a substrate surface of a substrate using a scanning probe microscopy device, wherein the scanning probe microscopy device comprises a scan head comprising a cantilever and a probe tip for being brought into contact with the substrate surface, wherein the scan head cooperates with a substrate carrier for moving the probe tip relative to the substrate surface for obtaining measurement data, the substrate carrier being configured for supporting the substrate, wherein the method comprises: mapping the one or more features by moving the probe tip relative to the substrate surface and bringing the probe in contact with the substrate surface continuously or intermittently for taking measurements at the substrate surface; wherein for performing the step of mapping, the method comprises applying a probe comprising a probe tip having an apex including an at least partially spherical rounded shape, wherein after performing the step of mapping, the method further comprises receiving the measurement data, wherein the method further comprises processing of the measurement data for generating a model of the one or more features on the substrate surface, wherein the step of processing comprises deconvolving the measurement data with probe tip shape data, the probe tip shape data being associated with the at least partially spherical rounded shape of the apex, wherein said deconvolving of the measurement data with the probe tip shape data yields surface profile data associated with the one or more features on the substrate surface.

[0027] Measurement data obtained from scanning probe microscopy devices typically include deflection signal data that indicate the deflection of the probe tip by the various features distributed across the scanned substrate surface. These data are shaped according to the shapes of the features to be mapped, but cannot be directly read as indicative of those shapes without further processing of the data. This is because the measurement data, originating from probe-substrate interactions, are provided by the convolution of the shape (i.e. contours) of the surface feature and the shape and orientation of the probe tip at each measurement point. Further processing of the measurement data in order to capture the shape of the surface feature therefore comprises a step of deconvolving the measurement data with probe tip shape data, wherein the probe tip shape data describes the shape of the probe tip. Ordinarily, the orientation of the probe tip at each measurement point adds further uncertainty to the measurement data, which can be corrected for during data processing. In the method according to the third aspect of the invention, this is made significantly more simple by the use of an at least partially spherical shape at the end of the probe tip. Spheres have a single, constant radius, meaning that the distance between the contact point between the probe tip and a feature, and the midpoint of the spherical shape will be rotationally invariant with respect to the orientation of the probe. In other words, angular displacements of the probe, or other deformations of the probe that occur during scanning of a substrate surface will leave this distance unaffected. By removing these variations from the measurement data, the deconvolution of the measurement data is greatly simplified through the use of a probe tip with an at least partially spherical shape at its end. This reduction in processing complexity is particularly beneficial for high-throughput scanning probe microscopy applications, including those in industrial settings. Thus the presently described third aspect may be applied more broadly in scanning probe microscopy methods and systems wherein one or more probe tips having an at least partially spherical shape are applied, in order to reduce complexity of the deconvolution step. Although it may be associated with the presently described concepts, this is thus not exclusively associated therewith and may be applied more broadly in other applications in the field of scanning probe microscopy. When processing complexity is lowered, data from scanning sessions can be interpreted and utilized more rapidly, reducing the time between scanning and results. This faster turnaround is vital in manufacturing processes where delays can disrupt workflow and affect the overall production timeline. Furthermore, by minimizing the potential for errors introduced by uncertainties caused by probe tip shapes, the quality control process can also be made more reliable and repeatable. This helps ensure that on-surface features are accurately mapped, for example in semiconductor manufacturing or materials testing. Additionally, simplified data processing can reduce computational load and the need for specialized software or hardware resources, potentially leading to cost savings and improved scalability when numerous scanning probe microscopy devices may be in operation simultaneously.

[0028] Brief description of the drawings

[0029] The invention will further be elucidated by description of some specific embodiments thereof, making reference to the attached drawings. The detailed description provides examples of possible implementations of the invention, but is not to be regarded as describing the only embodiments falling under the scope. The scope of the invention is defined in the claims, and the description is to be regarded as illustrative without being restrictive on the invention. In the drawings:

[0030] Figure 1 schematically illustrates a system for executing a method according to an embodiment of the invention.

[0031] Figure 2 schematically illustrates a method according to an embodiment of the invention.

[0032] Figures 3A and 3B schematically illustrate several embodiments of a probe applied for the step of mapping in the method according to an embodiment of the invention.

[0033] Figure 4 schematically illustrates the contact area of an embodiment of a probe applied for the step of mapping in the method according to an embodiment of the invention.

[0034] Figure 5 schematically illustrates a method according to an embodiment of the second aspect of the invention.

[0035] Figures 6 A and 6B depict a schematic view of a probe tip according to another example of the invention, wherein in figure 6B the probe tip of figure 6A is angled.

[0036] Figs. 7 A - 7C depict a schematic view of a further probe tip as a comparative example relative to figures 6A and 6B, wherein in Fig. 7B and 7C the probe tip of Fig. 7Ais angled.

[0037] Figures 8A - 8C depict a schematic view of a further probe tip in accordance with an example of the invention, wherein in figure 8B and 8C the probe tip of figure 8A is angled. Figures 9 A - 9D schematically illustrate a view of yet further probe tips in accordance with examples of the invention, wherein in figures 9B and 9D the respective probe tips of figures 9A and 9C are angled.

[0038] Figures 10A and 10B schematically illustrate how a spherically shaped probe tip differentially affects a measurement data deconvolution process compared to a non-spherically shaped probe tip.

[0039] Detailed description

[0040] Figure 1 schematically illustrates a system for executing a method according to an embodiment of the invention. The system comprises a scanning probe microscopy device 1 comprising a scan head 2 with a probe 3 including a probe tip 4. The scan head 2 cooperates with the substrate carrier 5, which supports the substrate 6, for mapping the substrate surface 61. In industrial settings, reaching high throughputs is crucial. In order to satisfy this need, a measurement resolution is defined before scanning a substrate 6, which is sufficiently high for obtaining a detailed image of critical parts of a substrate 6, but sufficiently low for enabling the scanning process to be performed rapidly. Based on this predefined measurement resolution, a pixel size is obtained for the pixels of the scan. This pixel size then defines a measurement area for each measurement in the scan, which is to be filled by the contact area between the rounded shape 41 of the probe tip 4 and the substrate surface 61. The rounded shape 41 at the apex of the probe tip 4 is then brought into contact with the substrate surface 61. In contact mode for example, a constant force is maintained continuously between the probe tip 4 and the substrate surface 61. As the rounded shape 41 moves across the substrate surface 61, variations in surface topography cause changes in the interaction forces between the probe and the substrate. A light source 7 emits a light beam 9 onto the back of the probe 3. Changes in the interaction forces between the probe 3 and substrate 6 will cause a deflection of the probe tip 4.

[0041] These deflections will cause the light beam 9 to be reflected by the probe 3 at a changed angle. This change is detected by an optical sensor 10 and used by a controller 11 to correct the probe position on the substrate 61. This correction may be done using a correction signal from the controller 11, or based on the deflection signal detected by the sensor 10, or by a combination of both signals. The correction is used to determine a dimension of an on-surface feature on the substrate 6 and to generate an image of the features on the substrate surface 61. Alternatively to contact mode, in tapping mode the probe tip 4 oscillates at high frequencies near its resonant frequency, such that contact between the rounded shape 41 and the substrate surface 61 is made intermittently. As the rounded shape 41 taps on the substrate surface 61, changes in amplitude, phase, or frequency of the oscillatory movement are monitored to detect variations in the topography of the substrate surface 61 and used to generate an image thereof. Because this method is performed using a rounded shape 41, which in each measurement of the scan makes contact with the substrate surface 61 in a contact area approximating the measurement area, the scan can be performed much more rapidly, which significantly enhances the suitability of the technique for industrial application. Moreover, this larger rounded shape 41 distributes the impact on the probe tip over a larger area than an ultra-fine tip would. This increases the lifetime of each probe and reduces the frequency with which it has to be replaced. This further increases the technique’s suitability for industrial applications. Also, the rounded shape 41 yields a contact area between the probe tip 4 and the substrate surface 61 that is larger than many small features or imperfections on the substrate surface 61, such as small cavities or small protruding features. Because the rounded shape 41 is very large compared to these imperfections, the probe tip 4 will easily slide over them while traversing the substrate surface 61. The invention therefore significantly reduces the amount of measurement noise caused by interactions between the probe and these small features. The method using a probe 3 with such a rounded shape 41 at the apex of the probe tip 4 can also be used for mapping features below the substrate surface 61, including buried interfaces of layers, or subsurface defects or inclusions such as the subsurface feature 12. This would involve applying an acoustic vibration 13 to the probe 3 or to the substrate 6. This vibration 13 then propagates through the substrate 6 and has signal components which, can be detected again at the substrate surface 61. For example, the vibration may have signal components with high frequencies (for example above 100 MHz), or signal components with lower frequencies (for example below 100 MHz). In the case of higher frequencies, the vibration 13 propagates through the substrate 6 and scatters from the feature 12. Some of the scattered vibration propagates back to the surface; this backscattered output signal may then be detected by the probe 3. In the case of lower frequencies, the feature 12 may be detected based on a mechanical response of the probe-substrate interaction caused by the vibration 13. For example, the substrate 6 may deform less when the vibration 13 is applied directly above the feature 12 than it would when the vibration 13 would be applied elsewhere on the substrate surface 61. In both cases, the probe will detect a signal component that has a frequency equal to the difference between two signal components of the applied acoustic vibration 13.

[0042] Figure 2 schematically illustrates a method according to an embodiment of the invention. The method illustrated in figure 2 may for example be executed using the system of figure 1. The method comprises a step SI of obtaining a pixel size for the pixels of a scan to be performed. This pixel size is associated with a measurement resolution for the scan defined beforehand. The pixel size also sets the measurement area for each measurement of the scan, in which the probe 3 is to make contact with the substrate surface 61. The step SI of obtaining a pixel size may comprise defining a measurement range on the substrate surface 61 which confines the scan to within definite boundaries thereon. In that case the measurement range and the predefined measurement resolution in combination can determine the amount of pixels for the scan. The pixel size may then be obtained such that all of the pixels together cover the entire measurement range. But alternatively the step SI of obtaining a pixel size may further involve defining a pixel spacing with which all of the pixels would be separated. In that case the measurement range would be covered by the pixels, but the pixels would leave space in between them. For example, the measurement areas may be positioned at critical regions on the substrate surface 61, and the measurement areas may be separated by the pixel spacing in non-critical regions of the substrate surface. The method may further comprise a step S2 of selecting a probe 3 to be applied in the step S4 of mapping. A user may have a number of probes at his disposal, each of which comprises a rounded shape at the apex of its probe tip for yielding a different contact area between the rounded shape and the substrate surface 61. The user may then select that probe which yields the contact area which most closely approximates the measurement area defined by the pixel size. Once the probe to be applied is selected, the method may comprise a step S3 of replacing a probe preinstalled on the scanning probe microscopy device 1 with the selected probe. For example, the preinstalled probe may have a rounded shape less suitable for the scan that is about to be performed, or may not comprise such a rounded shape at all. The selected probe will typically have a rounded shape with a radius of curvature that yields a contact area between the rounded shape 41 and the substrate surface 61 which deviates from the measurement area by less than 20%, preferably less than 10%, more preferably less than 5%. The method further comprises a step S4 of mapping the features on or below the substrate surface 61 by bringing the rounded shape 41 of the probe tip 4 in contact with the contact surface 61 and moving the rounded shape 41 relative to the substrate surface 61. The rounded shape 41 and the substrate surface 61 may either be brought into contact with each other continuously in contact mode, or may be brought into contact intermittently in tapping mode. As the probe tip 4 and the substrate surface 61 move relative to each other, the rounded shape 41 moves from pixel to pixel and in each pixel makes contact with the substrate surface 61 across an area substantially similar to the measurement area. At each pixel, a measurement may be taken by sensing a deflection of the probe tip 4 by the substrate 6 and correcting for this deflection. This correction may be performed based on a deflection signal measured by the optical sensor 10, or based on a correction signal based on how much the deflection differs from a predefined setpoint, generated by a controller 11. The correction may also be performed based on a combination of the two signals. The scanning process of the method according to these embodiments can be used for mapping of on-surface features, but may alternatively be used for mapping subsurface features below the substrate surface 61.

[0043] Figure 3A schematically illustrates an embodiment of a probe tip 4b applied for the step of mapping in the method according to an embodiment of the invention. The probe 4b comprises a rounded shape 41b at its apex. An ultra-fine probe tip 4a is shown in addition to probe tip 4b. Both probe tips 4a and 4b are shown in contact with a substrate surface 61 and with a sidewall 62 of an on-surface feature. Because probe tip 4b comprises a rounded shape 41b at its apex which has a radius of curvature for yielding a larger contact area with the substrate surface 61 than an ultra-fine tip, the distance dx2 between the center of probe tip 4b and the sidewall 62 is considerably larger than the distance dxl between the center of probe tip 4a and the sidewall 62. At the same time, the height dz of the sidewall in absolute terms is the same no matter which probe is applied. However, because the rounded shape 41b yields such a larger distance dx2 relative to dxl, the effective distance to be traversed by the probe tip in order to surmount the sidewall 62 is smaller for probe tip 4b than it is for probe tip 4a. Moreover, because the height dz is fixed, any probe when moved upward after collision with the sidewall 62 will rise above the sidewall 62 equally quickly. By contrast, since distance dx2 is larger than distance dxl, horizontally the probe tip 4b will move past the sidewall 62 to the point illustrated on the right in the figure more quickly than will the probe tip 4a. In particular, the horizontal speed vx2 of probe tip 4b will be greater than the horizontal speed vxl of probe tip 4a by a factor equal to the ratio of distance dx2 over dxl. This relation between horizontal speeds vxl and vx2 can be written as follows:

[0044] vxl dxl

[0045] vx2 dx2

[0046] In figure 3A, rounded shape 41b of probe tip 4b is shown as a spherical shape projecting transversely from the length of the probe tip, such that it provides a projected contact point between the probe tip 4b and the sidewall 61. Figure 3B schematically illustrates another embodiment of a probe tip 4c applied for the step of mapping in the method according to an embodiment of the invention. The same ultra-fine tip 4a is shown alongside it. Rounded shape 41c of probe tip 4c does not project transversely from the length of the probe tip 4c and is shown as a hemispherical shape. In alternative embodiments the rounded shape may be a similar shape, such as paraboloidal shapes, elliptical shapes or ovoidal shapes. In the embodiment shown in figure 3B, the height dz of the sidewall 62 is shown to be smaller than the radius of curvature of the rounded shape 41c. This provides the use of this probe tip 4c the additional advantage that collision between the probe tip 4c and the sidewall 62 will cause an upward force to be exerted on the rounded shape 41c, facilitating the upward movement of the probe tip 4c that is needed to surmount the feature. The probe tip 4c is therefore able to traverse the substrate surface significantly more quickly. Figure 4 schematically illustrates the contact area A2 of rounded shape 41b of probe tip 4b, and further schematically illustrates contact area Al of ultrafine probe tip 4a. During scanning of the substrate surface 61, any probe would encounter small defects 63, and normally an ultra-fine probe tip such as probe tip 4a is likely to get stuck in such defects 63. The probe may get stuck in small cavities, such as shown here, but may alternatively get stuck at small protruding imperfections. The probe tip 4a would then have to be lifted from the defect before scanning can continue; this significantly slows the scanning process, thereby adversely affecting the suitability of the technique for industrial applications. This is advantageously prevented in the present invention by the rounded shape 41b. The invention may comprise predefining a maximum expected defect size for defects 63. This predefined maximum expected defect size may be smaller than the features to be mapped, but larger than the sizes of the defects 63. A pixel size may then be obtained such that the resulting measurement area is larger than this predefined maximum expected defect size. The rounded shape 41b of probe tip 4b provides a contact area A2 that is larger than these defects. This prevents the probe tip 4b from getting stuck in these defects and allows the probe tip to easily slide across the substrate surface 61, despite the presence of these small features. In addition to the speed gained by sacrificing a degree of measurement resolution not necessary in industrial settings, the invention therefore additionally gains even more speed by preventing the probe tip from getting stuck in surface defects.

[0047] Figure 5 schematically illustrates a method according to an embodiment of the second aspect of the invention. In a step S5, a pixel size is determined based on the predetermined measurement resolution for scanning a substrate surface. In a step S6, the probe is provided with a rounded shape at its apex, where the radius of curvature is precisely controlled to match the previously obtained pixel size. The control over the curvature ensures that when the probe comes into contact with the substrate surface, the contact area is substantially similar in size to the measurement area defined by the pixel size. This controlled shaping of the probe tip can be achieved using advanced manufacturing techniques such as focused ion beam milling or chemical vapor deposition. These techniques allow for precise adjustments to the probe tip's curvature, ensuring that the probe is optimally tailored to meet users’ specific measurement requirements. By providing a probe with high control over the radius of curvature of the rounded shape, the method enables to optimize the trade-off between measurement accuracy and scanning speed. Furthermore, by providing a probe with a contact area that is substantially larger than small surface imperfections, the method reduces the likelihood of the probe tip getting stuck or encountering disturbances that could introduce noise into the measurement signals. This not only improves measurement stability but also extends the probe's lifetime by minimizing wear and tear. Additionally, the larger contact area allows for a more stable and consistent interaction with the substrate.

[0048] Turning to Figs. 6A and 6B, an example of a probe tip 4 according to the invention is depicted. The rounded shape 41 of the probe tip 4 in this embodiment is a spherical shape provided at the tip of the probe 3 such that the apex of the probe tip 4 is located on the sphere. The spherical shape 41 of the probe tip 4 has a constant radius, and its midpoint coincides with the longitudinal axis through the probe tip such that the spherical tip is rotational symmetric around the longitudinal axis of the probe tip 4. In Fig. 6A the probe tip 4 is in an upright position, in Fig. 6B the probe tip 4 is angled. This angling may be the result of the suspension from the scan head of the scanning probe microscope, a periodic motion of the probe tip 4, or of external forces acting upon the probe tip 4. Comparing Fig.

[0049] 6A and 6B, it can be seen that the projected width of the probe tip, wO and wl of Fig. 6A and 6B respectively, is the same. As a result, the spherical shape of probe tip 4 renders deconvolution to be independent of the angle of the probe relative to the surface of the sample. As a result, the process of deconvolution is less complex. In Figs. 7A-7C and 8A-8C a comparison is given with different probe tip 4 shapes.

[0050] Turning to Figs. 7A-7C and 8A-8C, as comparative examples with respect to figures 6A and 6B, probe tips 4 have been depicted having a square probe tip 42 (in Figs. 7A- 7C) and, in accordance an alternative embodiment, a ovoid shape 41 at the apex of probe tip 4 in Figs. 8A - 8C. In Figs. 7A and 8A, the probe tip 4 is in an upright position, having a projected width of wO on the surface of a sample during use. In Figs. 7B and 8B, the probe tip 4 has been angled relative to the upright position over an angle a. Due to the angling, it can be seen that both probe tips 4 of Figs. 7B and 8B tilt, and have a displacement height dz and a projected width of wl. The projected width wl in Figs. 7B and 8B is larger than the projected width wO of Figs. 7A and 8A due to the tilting. The incorrect projected width wl needs to be corrected for, of which an example is shown in Figs. 7C and 8C. The incorrect projected width wl is the sum of the projected width wO and the displacement width dx. Although it is possible to deconvolute the angled probe tip 4 of Figs. 7B and 8B, doing so will result in an error of value dx in x-direction and dz in z-direction. The displacement width dx and height dz of the probe tip of Figs. 7A - 7C can be determined using the following equations respectively: dx = h0 * cos (α) and dz = w0 * sin (α), in which h1 is the length of the probe tip 4. For Figs. 8A-8C, the displacement width dx and height dz of the probe tip 4 can be determined using the following equations respectively: dx = 4r — (2r + 2r * cos(a)) and dz = 2r * sin (a). Hence, in either case of figures 7 and 8, the angle must be determined in order for the correction to be carried out. Comparing to the spherically shaped probe tip 4 of Figs. 6A and 6B, it can be seen that the deconvolution process is less complex and results in less error when a spherical shaped probe tip 4 is used.

[0051] In figures 9A - 9D, two examples of a probe tip 4 in accordance with embodiments of the invention are shown. In the embodiment of figures 9A and 9B, the rounded shape 41 of the probe tip 4 is a spherical shape positioned at the end of probe 3, with the apex of probe tip 4 lying on the surface of the sphere. The spherical shape 41 of the probe tip 4 has a single radius yielding a width wO of the spherical shape 41 that is equal to the width of the probe tip 4. In the embodiment shown in figures 9C and 9D, the spherical shape 41 has a width wO that is smaller than the width of the probe tip 4. The midpoints of the spherical shapes of both of these two embodiments align with the longitudinal axes through the respective probe tips, making the spherical tips rotationally symmetric around these respective axes. In figures 9A and 9C, probe tips 4 are shown in an upright position, while in figures 9B and 9D, the probe tips 4 are shown at an angle. This angling may for example result from suspension of the probe tip 4 from the scanning probe microscope’s scan head, from a periodic motion of probe tip 4, or from external forces acting on it. It becomes evident when comparing the figures 9A and 9B or figures 9C and 9D, that the projected width of the probe tip, wO in figures 9A and 9C and wl in figures 9B and 9D, is unaffected by the angling a in both embodiments. The spherical shape of probe tip 4 therefore also makes deconvolution independent of the probe's angle relative to the sample surface when the spherical shape 41 is either as wide as the probe tip 4, or less wide than the probe tip 4. This significantly simplifies the deconvolution process in these embodiments as well.

[0052] Figure 10A schematically illustrates a probe 3 scanning a substrate surface 61 as the spherical shape 41 of the probe tip 4 makes contact with a sidewall 62 of an on-surface feature 64. The direction of the probe 3 relative to the surface 61 is indicated by arrow 66. The probe 3 in figure 10A is oriented at an angle 9 with respect to the substrate surface 61. As the probe tip 4 moves over the feature 64, the probe tip 4 will encounter the edge 65 thereof. Upon going over the edge 65, the probe 3 will be deflected, resulting in a deflection signal being measured. An example of resulting measurement data 100, in the form of a deflection signal u against a horizontal probe position x is depicted in figure 10B. The measurement data 100 are deconvolved with probe tip shape data associated with the shape at the end of probe tip 4. In embodiments of the first aspect of the invention where the rounded shape is spherical, and in the method according to the third aspect of the invention, the deconvolution is invariant with respect to the angling 9 of the probe 3 because the constant radius of the spherical shape 41 of the probe tip 4. Therefore, the measurement signal 100 of deflection u will be invariant to angle 9. The shape of edge 65 can be obtained by deconvolving the round shape 101 of the measurement signal thereof with the shape of the probe tip 4. In other embodiments, the probe tip may be provided with partially spherical rounded shapes, such as hemi-spherical shapes. If the probe tip 4 were instead provided with a non-spherical shape, such as elliptical shape 43, scanning the substrate surface 61 with that probe will result a measurement signal that is dependent on the orientation angle 0 of the probe 3, which is therefore more difficult to deconvolve. This is an example of how the deconvolution of the measurement data 100 would be more complex than when a probe tip 4 with a spherically shaped tip is used, because additional uncertainties are contained within the measurement data. The rotational symmetry of spherical shapes alleviates these effects, significantly simplifying the deconvolution process.

[0053] The present invention has been described in terms of some specific embodiments thereof. It will be appreciated that the embodiments shown in the drawings and described herein are intended for illustrated purposes only and are not by any manner or means intended to be restrictive on the invention. It is believed that the operation and construction of the present invention will be apparent from the foregoing description and drawings appended thereto. It will be clear to the skilled person that the invention is not limited to any embodiment herein described and that modifications are possible which should be considered within the scope of the appended claims. Also kinematic inversions are considered inherently disclosed and to be within the scope of the invention. Moreover, any of the components and elements of the various embodiments disclosed may be combined or may be incorporated in other embodiments where considered necessary, desired or preferred, without departing from the scope of the invention as defined in the claims.

[0054] In the claims, any reference signs shall not be construed as limiting the claim. The term 'comprising' and ‘including’ when used in this description or the appended claims should not be construed in an exclusive or exhaustive sense but rather in an inclusive sense. Thus the expression ‘comprising’ as used herein does not exclude the presence of other elements or steps in addition to those listed in any claim. Furthermore, the words ‘a’ and ‘an’ shall not be construed as limited to ‘only one’, but instead are used to mean ‘at least one’, and do not exclude a plurality. Features that are not specifically or explicitly described or claimed may be additionally included in the structure of the invention within its scope. Any of the claimed or disclosed devices or portions thereof may be combined together or separated into further portions unless specifically stated otherwise, without departing from the claimed invention. Expressions such as: "means for...” should be read as: "component configured for..." or "member constructed to..." and should be construed to include equivalents for the structures disclosed. The use of expressions like: "critical", "preferred", "especially preferred" etc. is not intended to limit the invention. Additions, deletions, and modifications within the purview of the skilled person may generally be made without departing from the spirit and scope of the invention, as is determined by the claims. The invention may be practiced otherwise then as specifically described herein, and is only limited by the appended claims.

Claims

Claims1. Method of mapping one or more features on or below a substrate surface of a substrate using a scanning probe microscopy device, wherein the scanning probe microscopy device comprises a scan head comprising a cantilever and a probe tip for being brought into contact with the substrate surface, wherein the scan head cooperates with a substrate carrier for moving the probe tip relative to the substrate surface for obtaining measurement data, the substrate carrier being configured for supporting the substrate,wherein the method comprises:mapping the one or more features by moving the probe tip relative to the substrate surface and bringing the probe in contact with the substrate surface continuously or intermittently for taking measurements at the substrate surface;wherein prior to the step of mapping, the method comprises: obtaining, for each pixel of a plurality of pixels wherein the measurements are to be taken, a pixel size associated with a predetermined measurement resolution, wherein the pixel size defines a measurement area for the probe tip for taking said measurements at each pixel at the substrate surface, applying, for performing the step of mapping, a probe comprising a probe tip having an apex including a rounded shape, the rounded shape having a radius of curvature such as to yield, in contact with the substrate surface, a contact area of a size substantially similar to said measurement area.

2. Method according to claim 1, wherein the step of obtaining a pixel size comprises defining a measurement range on the substrate surface for confining the moving of the probe tip relative to the substrate surface, wherein the measurement range and the predefined measurement resolution set an amount of pixels of the plurality of pixels.

3. Method according to claim 2, wherein one of:the step of obtaining a pixel size is performed, such that the measurement range is completely covered by the plurality of pixels, such that each measurement area is positioned mutually adjacent in the measurement range; orthe step of obtaining a pixel size further comprises defining a pixel spacing, wherein the plurality of pixels and the pixel spacing are arranged across the measurement range in an alternating order.

4. Method according to any of the preceding claims, wherein prior to the step of mapping, the method comprises selecting the probe applied for performing the step of mapping from a plurality of probes, wherein the probe tip of each of the plurality of probes comprises an apex having a rounded shape, wherein the rounded shape of the apex of each of the plurality of probes has a radius of curvature such as to yield, in contact with the substrate surface, a mutually different contact area.

5. Method according to claim 4, wherein the step of selecting is performed, such as to minimize a deviation from the measurement area by the contact area of the rounded shape and the substrate surface.

6. Method according to claim 4 or 5, wherein prior to the step of mapping, the method comprises replacing a probe preinstalled on the scan head with the selected probe.

7. Method according to any of the preceding claims, wherein a deviation from the measurement area by the contact area of the rounded shape and the substrate surface is smaller than 20% of the measurement area, preferably smaller than 10% of the measurement area, more preferably smaller than 5% of the measurement area.

8. Method according to any of the preceding claims, wherein for performing the step of mapping of one or more features below the substrate surface, the method comprises applying an acoustic vibration to the probe or to the substrate, the acoustic vibration comprising signal components such as to establish at least an output signal portion having an amplitude and a frequency that are within a sensitivity range of the probe.

9. Method according to claim 8, wherein the signal components include at least a first signal component and a second signal component, wherein at least one of:the first signal component or the second signal component comprises a frequency below 100 MHz; andthe first signal component or the second signal component comprises a frequency above 100 MHz;wherein the frequency of the output signal portion is equal to a difference between the frequency of the first signal component and the frequency of the second signal component.

10. Method according to any of the preceding claims, wherein for performing the step of mapping of one or more features on the substrate surface, the method comprises sensing a deflection of the probe tip by a feature on the substrate surface,wherein the method further comprises correcting for the deflection of the probe tip, for determining a dimension of the feature, wherein at least one of:the step of correcting is performed based on a deflection signal of the scanning probe microscopy device; andthe step of correcting is performed based on a correction signal generated by a controller of the scanning probe microscopy device, wherein the correction signal is based on a difference between the deflection signal and a predefined setpoint.

11. Method according to any of the preceding claims, wherein the step of mapping is performed using a probe having a rounded shape including a radius of curvature such that during the step of mapping, the probe is configured for making contact with a sidewall of a feature on the substrate surface at a contact point on the rounded shape, the contact point being positioned below a center of the rounded shape.

12. Method according to any of the preceding claims, wherein the rounded shape is one of a group comprising: spherical shapes, hemispherical shapes, ellipsoidal shapes, paraboloidal shapes, and ovoidal shapes.

13. Method according to any of the preceding claims, wherein after performing the step of mapping of one or more features on the substrate surface using a probe comprising a probe tip having an apex including an at least partially spherical rounded shape, the method further comprises receiving the measurement data, wherein the method further comprises processing of the measurement data for generating a model of the one or more features on the substrate surface,wherein the step of processing comprises deconvolving the measurement data with probe tip shape data, the probe tip shape data being associated with the at least partially spherical rounded shape of the apex, wherein said deconvolving of the measurement data with the probe tip shape data yields surface profile data associated with the one or more features on the substrate surface.

14. Method of manufacturing a probe for use in a method according to any one or more of the preceding claims, the probe being suitable for mapping one or more features on or below a substrate surface of a substrate using a scanning probe microscopy device, the method comprising manufacturing a cantilever of the probe and a probe tip for being brought into contact with the substrate surface, said manufacturing comprising the steps of:obtaining a pixel size associated with a predetermined measurement resolution, wherein the pixel size defines a measurement area for the probe tip for taking measurements at a pixel on a surface of a substrate supported by the scanning probe microscopy device, andproviding the probe having a rounded shape at an apex of the probe tip, said providing being controlled such that the rounded shape has a radius of curvature for yielding, in contact with the substrate surface, a contact area of a size substantially similar to said measurement area.

15. Method of mapping one or more features on a substrate surface of a substrate using a scanning probe microscopy device, wherein the scanning probe microscopy device comprises a scan head comprising a cantilever and a probe tip for being brought into contact with the substrate surface, wherein the scan head cooperates with a substrate carrier for moving the probe tip relative to thesubstrate surface for obtaining measurement data, the substrate carrier being configured for supporting the substrate,wherein the method comprises:mapping the one or more features by moving the probe tip relative to the substrate surface and bringing the probe in contact with the substrate surface continuously or intermittently for taking measurements at the substrate surface;wherein for performing the step of mapping, the method comprises applying a probe comprising a probe tip having an apex including an at least partially spherical rounded shape,wherein after performing the step of mapping, the method further comprises receiving the measurement data, wherein the method further comprises processing of the measurement data for generating a model of the one or more features on the substrate surface,wherein the step of processing comprises deconvolving the measurement data with probe tip shape data, the probe tip shape data being associated with the at least partially spherical rounded shape of the apex, wherein said deconvolving of the measurement data with the probe tip shape data yields surface profile data associated with the one or more features on the substrate surface.

Images