# US 10,119,990 B2 · Scanning probe microscope and method for examining a surface with a high aspect ratio > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,119,990 B2 - Document ID: US10119990B2 - Status: Granted - Kind: B2 - Application number: 15/386,203 - Filed: 2016-12-21 - Published: 2017-04-13 - Granted: 2018-11-06 - Earliest claimed: 2014-06-26 - Assignees: Carl Zeiss SMT GmbH - Applicants: Carl Zeiss SMT GmbH - Inventors: Christof Baur; Klaus Edinger - Web page: https://patentgrep.com/patent/US10119990B2 ## CPC - G01Q 10/045: {Self-actuating probes, i.e. wherein the actuating means for driving are part of the probe itself, e.g. piezoelectric means on a cantilever probe} - G01Q 10/00: Scanning or positioning arrangements, i.e. arrangements for actively controlling the movement or position of the probe - G01Q 10/06: Circuits or algorithms therefor - G01Q 10/065: {Feedback mechanisms, i.e. wherein the signal for driving the probe is modified by a signal coming from the probe itself} - G01Q 70/14: Particular materials - G01Q: SCANNING-PROBE TECHNIQUES OR APPARATUS; APPLICATIONS OF SCANNING-PROBE TECHNIQUES, e.g. SCANNING PROBE MICROSCOPY [SPM] ## Abstract The invention relates to a scanning probe microscope, having: (a) a scanning device for scanning a measurement tip over a surface; (b) a cantilever for the measurement tip, wherein the cantilever has a torsion region; (c) wherein the torsion region is configured such that it undergoes torsion when a control signal is applied and thereby pivots the measurement tip; and (d) a control device for outputting the control signal when the measurement tip scans a region of the surface that can be examined more closely with a pivoted measurement tip than without pivoting the measurement tip. ## Claims ### Claim 1 A scanning probe microscope, having: a. a scanning device for scanning a measurement tip over a surface; b. a cantilever for the measurement tip, wherein the cantilever has a torsion region; c. wherein the torsion region is configured such that it undergoes torsion when a control signal is applied and thereby pivots the measurement tip; and d. a control device for determining, when the measurement tip scans a region of the surface, whether the region can be examined more closely with a pivoted measurement tip than without pivoting the measurement tip, and outputting the control signal in response to a determination that the region of the surface can be examined more closely with the pivoted measurement tip than without pivoting the measurement tip, wherein the scanning device is configured to extend a distance feedback loop means for the z-movement to a z-x-movement to monitor a distance between the surface and the measurement tip along a z-x plane based on at least one parameter measured by the scanning device, wherein the x-direction indicates a fast scan direction, and the z-direction is perpendicular to the surface, wherein the control device is configured to generate an image of the region of the surface based on data gathered from a first scan of the region of the surface, and analyze the image to determine whether indications are present in the image that the measurement tip was not able to realistically scan the region of the surface in which a detected topography of a portion of the region of the surface is similar to or the same as a contour of the measurement tip, wherein the control device is configured to, upon determining that indications are present in the image that the measurement tip was not able to realistically scan the region of the surface, cause the measurement tip to have a first pivot angle and perform a second scan of the region of the surface with the measurement tip having the first pivot angle, wherein the control device is configured to generate a second image of the region of the surface based on data gathered from the second scan of the region of the surface, and analyze the second image to determine whether indications are present in the second image that the measurement tip was not able to realistically scan the region of the surface, and wherein the control device is configured to, upon determining that indications are present in the second image that the measurement tip was not able to realistically scan the region of the surface, cause the measurement tip to have a second pivot angle and perform a third scan of the region of the surface with the measurement tip having the second pivot angle. ### Claim 2 (depends on 1) The scanning probe microscope as claimed in claim 1, wherein the torsion region comprises at least in a partial region at least two material layers that are connected to one another and have different coefficients of thermal expansion. ### Claim 3 (depends on 2) The scanning probe microscope as claimed in claim 2, wherein the torsion region comprises at least a first region having at least two first material layers, which are connected to one another, for setting a rough pivoting movement of the measurement tip, and at least a second region having at least two second material layers, which are connected to one another, for setting a fine pivoting movement of the measurement tip, or wherein the torsion region comprises at least 2 partial regions with implanted material for setting a rough pivoting movement and a fine pivoting movement of the measurement tip. ### Claim 4 (depends on 2) The scanning probe microscope as claimed in claim 2, wherein the region of the at least two material layers, which are connected to one another, or the at least one partial region of implanted material extends over the entire cantilever. ### Claim 5 (depends on 2) The scanning probe microscope as claimed in claim 2, wherein at least one of the at least two material layers, which are connected to one another, or at least a partial region of implanted material comprises a heating resistor. ### Claim 6 (depends on 1) The scanning probe microscope as claimed in claim 1, wherein at least a partial region of the torsion region comprises implanted material such that the partial region and the torsion region have different coefficients of thermal expansion. ### Claim 7 (depends on 1) The scanning probe microscope as claimed in claim 1, wherein the torsion region has a material in an arrangement that is configured to, when the control signal is applied, keep a first part of the arrangement substantially at a first temperature, and to keep a second part of the arrangement substantially at a second temperature, wherein the first and second temperatures differ. ### Claim 8 (depends on 1) The scanning probe microscope as claimed in claim 1, furthermore having a laser system which is configured to locally heat the torsion region when the control signal is applied. ### Claim 9 (depends on 1) The scanning probe microscope as claimed in claim 1, furthermore having a heating apparatus which is configured to locally heat the torsion region when the control signal is applied. ### Claim 10 (depends on 1) The scanning probe microscope as claimed in claim 1, wherein the torsion region comprises at least one piezo actuator. ### Claim 11 (depends on 1) The scanning probe microscope as claimed in claim 1, wherein the control device is configured to modulate the control signal to excite the measurement tip to oscillate. ### Claim 12 (depends on 1) The scanning probe microscope as claimed in claim 1, wherein the torsion region is configured to pivot the measurement tip at an angle range of ±5°. ### Claim 13 (depends on 1) The scanning probe microscope as claimed in claim 1, wherein the cantilever and the measurement tip have a resonant frequency in the range of 100 Hz-5 MHz. ### Claim 14 (depends on 1) The scanning probe microscope as claimed in claim 1, wherein the scanning device is configured to add a signal of the z-movement to a signal for the x-movement. ### Claim 15 (depends on 1) The scanning probe microscope as claimed in claim 1, wherein the cantilever is connected to an attachment unit in which electrical connections are integrated that lead to the torsion region. ### Claim 16 (depends on 1) The scanning probe microscope as claimed in claim 1, wherein the cantilever has at least one sensor for determining the pivoting of the measurement tip. ### Claim 17 (depends on 1) The scanning probe microscope of claim 1 in which the torsion region is configured to pivot the measurement tip at an angle range of at least one of ±10°, ±15°, or ±20°. ### Claim 18 (depends on 1) The scanning probe microscope of claim 1 in which the cantilever and the measurement tip have a resonant frequency in the range of 500 Hz-1 MHz. ### Claim 19 (depends on 1) The scanning probe microscope of claim 1 in which the cantilever and the measurement tip have a resonant frequency in the range of 1 kHz-500 kHz. ### Claim 20 (depends on 1) The scanning probe microscope of claim 1 in which the cantilever and the measurement tip have a resonant frequency in the range of 2 kHz-200 kHz. ### Claim 21 (depends on 1) The scanning probe microscope of claim 1 in which the control device causes the measurement tip to have a first pivot angle during a first scan and a second pivot angle during a second scan in which the second pivot angle is different from the first pivot angle. ### Claim 22 (depends on 1) The scanning probe microscope of claim 1 in which the control device is configured to determine whether the region can be examined more closely with a pivoted measurement tip than without pivoting the measurement tip by at least in part determining whether a detected surface topography in at least one portion of the region is similar to or the same as the contour of the measurement tip. ### Claim 23 (depends on 1) The scanning probe microscope of claim 1 in which the control device is configured to determine whether the region can be examined more closely with a pivoted measurement tip than without pivoting the measurement tip by at least in part determining whether the region has a high aspect ratio that is greater than a predetermined value. ### Claim 24 (depends on 1) The scanning probe microscope of claim 1 in which the scanning device is configured to implement the distance feedback loop for the z-x-movement to monitor the distance between the surface and the measurement tip along the z-x plane based on at least one of a tunnel current between the surface and the measurement tip, a deflection of the measurement tip, a magnetic force between the surface and the measurement tip, evanescent electromagnetic waves indicating interaction between the surface and the measurement tip, or acoustic near-field interactions between the surface and the measurement tip. ### Claim 25 A method for examining a surface with a high aspect ratio, including: a. scanning a measurement tip over the surface, wherein the measurement tip is attached to a cantilever, and the cantilever has a torsion region; b. making a decision regarding, when the measurement tip scans a region of the surface, whether the region can be examined more closely with a pivoted measurement tip than without pivoting the measurement tip on the basis of a comparison of a just detected topography of the surface with a contour of the measurement tip; c. applying a control signal upon making the decision that when the measurement tip scans the region of the surface, the region can be examined more accurately with the pivoted measurement tip than without pivoting the measurement tip; d. in response to the control signal, subjecting the torsion region to torsion for pivoting the measurement tip; e. on the basis of a detected topography of the surface, deciding whether the measurement tip is pivoted; f. generating the just detected topography of the surface based on data gathered from a first scan of the surface, and analyzing the just detected topography and the contour of the measurement tip to determine whether indications are present in the just detected topography that the measurement tip was not able to realistically scan the surface in which the just detected topography is similar to or the same as a contour of the measurement tip; g. upon determining that indications are present in the just detected topography of the surface that the measurement tip was not able to realistically scan the region of the surface, causing the measurement tip to have a first pivot angle and performing a second scan of the region of the surface with the measurement tip having the first pivot angle, h. generating a second just detected topography of the surface based on data gathered from the second scan of the region of the surface, and analyzing the second just detected topography of the surface to determine whether indications are present in the second just detected topography of the surface that the measurement tip was not able to realistically scan the region of the surface, and i. upon determining that indications are present in the second just detected topography of the surface that the measurement tip was not able to realistically scan the region of the surface, causing the measurement tip to have a second pivot angle and performing a third scan of the region of the surface with the measurement tip having the second pivot angle. ### Claim 26 (depends on 25) The method as claimed in claim 25, wherein a scanning probe microscope is used for carrying out at least one of the method steps, the scanning probe microscope comprising: a scanning device for scanning the measurement tip over the surface; the cantilever having the torsion region, in which the torsion region is configured such that it undergoes torsion when the control signal is applied and thereby pivots the measurement tip; and a control device for outputting the control, in which the scanning device is configured to extend a distance feedback loop means for the z-movement to a z-x-movement, wherein the x-direction indicates a fast scan direction.