# US 7,607,342 B2 · Method and apparatus for reducing lateral interactive forces during operation of a probe-based instrument > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 7,607,342 B2 - Document ID: US7607342B2 - Status: Granted - Kind: B2 - Application number: 11/380,338 - Filed: 2006-04-26 - Published: 2007-11-01 - Granted: 2009-10-27 - Earliest claimed: 2006-04-26 - Assignees: Vecco Instruments, Inc. - Inventors: Lin Huang; Charles Meyer - Web page: https://patentgrep.com/patent/US7607342B2 ## CPC - G01Q 10/065: {Feedback mechanisms, i.e. wherein the signal for driving the probe is modified by a signal coming from the probe itself} - B82Y 35/00: Methods or apparatus for measurement or analysis of nanostructures - G01Q: SCANNING-PROBE TECHNIQUES OR APPARATUS; APPLICATIONS OF SCANNING-PROBE TECHNIQUES, e.g. SCANNING PROBE MICROSCOPY [SPM] - B82Y: SPECIFIC USES OR APPLICATIONS OF NANOSTRUCTURES; MEASUREMENT OR ANALYSIS OF NANOSTRUCTURES; MANUFACTURE OR TREATMENT OF NANOSTRUCTURES ## Abstract A cantilever probe-based instrument is controlled to reduce the lateral loads imposed on the probe as a result of probe/sample interaction. In a preferred embodiment, the probe tip and/or sample are driven to move laterally relative to one another as a function of cantilever deflection in order to compensate for lateral tip motion that would otherwise be caused by cantilever deflection. In the case of a probe having a passive cantilever, the sample and/or the probe as a whole are driven to move laterally to obtain the desired magnitude of compensation as direct function of cantilever deflection. In the case of a probe having an active cantilever, the sample or probe may be moved as a function of cantilever drive signal, or the cantilever may be controlled to bend as a function of cantilever drive signal so that the tip moves to obtain the desired magnitude of compensation. ## Claims ### Claim 1 A method comprising: causing a cantilever-based probe of an instrument to interact with a sample while laterally moving at least a tip of the probe relative to the sample so as to reduce lateral loads that would otherwise be imposed on the probe as a result of probe/sample interaction, the magnitude of the relative lateral motion being a predetermined function of cantilever deflection, wherein the moving step comprises transmitting a lateral compensation signal to an actuator of the instrument that is pre-calibrated prior to the moving step to determine the relationship between cantilever deflection and lateral motion. ### Claim 2 (depends on 1) The method as recited in claim 1, wherein the cantilever is a passive cantilever including a base and a free end portion that bears the tip, and wherein the moving step comprises moving the probe as a whole relative to the sample and is performed directly as a function of cantilever deflection. ### Claim 3 (depends on 2) The method as recited in claim 2, wherein the moving step comprises moving the sample laterally while the probe remains laterally stationary. ### Claim 4 (depends on 2) The method as recited in claim 2, wherein the moving step comprises moving the probe laterally while the sample remains laterally stationary. ### Claim 5 (depends on 2) The method as recited in claim 2, wherein the magnitude of the relative lateral motion is a predetermined direct function of measured cantilever deflection. ### Claim 6 (depends on 1) The method as recited in claim 1, wherein the probe is an active probe which has an active cantilever including a base, a free end portion that bears the tip and an actuator that is selectively energizable to bend the cantilever, and wherein the moving step is performed as a function of a drive signal supplied to the active cantilever. ### Claim 7 (depends on 6) The method as recited in claim 6, wherein the moving step is performed without measuring an angle of the free end of the cantilever. ### Claim 8 (depends on 1) The method as recited in claim 1, wherein the relative lateral motion is controlled in an open loop manner without feedback. ### Claim 9 A method comprising: causing a cantilever-based probe of an instrument to interact with a sample while laterally moving at least a tip of the probe relative to the sample so as to reduce lateral loads that would otherwise be imposed on the probe as a result of probe/sample interaction, the magnitude of the relative lateral motion being a predetermined function of cantilever deflection, wherein the moving step comprises transmitting a lateral compensation signal to an actuator of the instrument that is pre-calibrated prior to the moving step to determine the relationship between cantilever deflection and lateral motion; and, prior to the causing step calibrating the instrument to obtain lateral compensation signals for a range of cantilever deflection values. ### Claim 10 (depends on 9) The method as recited in claim 9, wherein the calibrating step comprises, for a particular cantilever deflection value, adjusting a magnitude of the lateral compensation signal so that an image of a particular feature remains at least substantially un-shifted when the cantilever deflection value is changed. ### Claim 11 (depends on 10) The method as recited in claim 10, wherein the calibrating step comprises, scanning the feature at the particular cantilever deflection value and obtaining an initial image of the feature, then changing cantilever deflection value, then scanning the feature again and obtaining images of the feature while adjusting the magnitude of the lateral compensation signal until any observed lateral shifts in the images, as compared to the initial image, are at least substantially eliminated. ### Claim 12 (depends on 11) The method as recited in claim 11, wherein the calibrating step comprises adjusting the magnitude of the compensation signal to at least substantially eliminate changes in the slope of displacement curves generated from the engagement process. ### Claim 13 (depends on 9) The method as recited in claim 9, wherein the calibrating step comprises, for a particular cantilever deflection value obtained when engaging a deep feature with the probe, adjusting the lateral compensation signal to at least substantially eliminate cantilever buckling during the engagement process. ### Claim 14 (depends on 9) The method as recited in claim 9, wherein the calibrating step comprises, for a particular cantilever deflection value obtained when indenting a tearable material, adjusting the magnitude of the lateral compensation signal to at least substantially eliminate material tearing caused by deflection induced tip lateral loads. ### Claim 15 (depends on 14) The method as recited in claim 14, wherein the material is an anisotropic material. ### Claim 16 (depends on 9) The method as recited in claim 9, wherein the calibrating step comprises, for a particular cantilever deflection value obtained when indenting a sample having a surface that is softer than the tip of the probe, adjusting the magnitude of the lateral compensation signal to achieve at least substantially uniform pileup of material ahead of and behind the tip. ### Claim 17 A method comprising: decreasing the spacing between a sample and a probe of a probe-based instrument, the probe including a passive cantilever having a fixed end and a free end portion that bears a tip, the cantilever deflecting as a result of probe/sample interaction occurring during at least part of the decreasing step, and during the decreasing step, energizing an actuator to move the sample relative to the probe to at least substantially eliminate lateral loads that would otherwise be imposed on the probe as a result of the probe/sample interaction, the magnitude of movement being a direct function of actual cantilever deflection and being predetermined prior to the decreasing step. ### Claim 18 (depends on 17) The method as recited in claim 17, wherein the magnitude of the relative lateral motion is a predetermined direct function of measured cantilever deflection. ### Claim 19 (depends on 17) The method as recited in claim 17, wherein the relative lateral motion is controlled in an open loop manner without feedback. ### Claim 20 A method comprising: decreasing the spacing between a sample and a tip of a probe of a probe-based instrument, the probe including an active cantilever having a fixed end, a free end portion that bears the tip, and an actuator that is selectively energizable to bend the cantilever, the cantilever deflecting as a result of probe/sample interaction occurring during at least part of the decreasing step, and during the decreasing step, energizing an actuator to move at least the tip of the probe laterally relative to the sample to at least substantially eliminate lateral loads that would otherwise be imposed on the probe as a result of the probe/sample interaction, the magnitude of movement being a predetermined function of a monitored drive signal supplied to the active cantilever and being predetermined prior to the decreasing step, the monitored drive signal being a function of actual cantilever deflection. ### Claim 21 (depends on 20) The method as recited in claim 20, wherein the moving step comprises energizing the active cantilever to move the probe tip. ### Claim 22 (depends on 20) The method as recited in claim 20, wherein the moving step comprises energizing a separate actuator to move at least one of the probe as a whole and the sample laterally. ### Claim 23 An instrument comprising: (A) a probe including a cantilever and a tip mounted on the cantilever; and (B) a controller that transmits a lateral compensation signal to at least one actuator to move at least the tip of the probe relative to a sample while the probe is interacting with the sample so as to at least substantially eliminate lateral loads that would otherwise be imposed on the probe as a result of probe/sample interaction, the lateral compensating signal being a predetermined function of cantilever deflection that is predetermined prior to the probe-sample interaction. ### Claim 24 (depends on 23) The instrument as recited in claim 23, wherein the cantilever is a passive cantilever including a base and a free end portion that bears the tip, and wherein the controller controls an actuator directly as a function of cantilever deflection to move the probe as a whole relative to the sample to effect lateral load reduction. ### Claim 25 (depends on 24) The instrument as recited in claim 24, wherein the controller controls an xy actuator to move the sample laterally while the probe remains laterally stationary. ### Claim 26 (depends on 24) The instrument as recited in claim 24, wherein the controller controls an xy actuator to move the probe laterally while the sample remains laterally stationary. ### Claim 27 (depends on 23) The instrument as recited in claim 23, wherein the cantilever is an active cantilever including an actuator that is selectively energizable to bend the cantilever, wherein the controller controls the actuator as a function of a drive signal supplied to the active cantilever. ### Claim 28 (depends on 23) The instrument as recited in claim 23, wherein the lateral compensation signal is pre-calibrated prior moving the probe tip relative to the sample. ### Claim 29 (depends on 23) The instrument as recited in claim 23, wherein the lateral compensation signal is a predetermined direct function of measured cantilever deflection. ### Claim 30 (depends on 23) The instrument as recited in claim 23, wherein the lateral compensation signal is generated in an open loop manner without feedback. ### Claim 31 A method comprising: causing a cantilever-based probe of an instrument to interact with a sample; and, during the causing step; monitoring a parameter indicative of actual cantilever deflection resulting from probe/sample interaction, and, in response to the monitoring step, laterally moving at least a tip of the probe relative to the sample so as to reduce lateral loads that would otherwise be imposed on the probe as a result of probe/sample interaction, the magnitude of the relative lateral motion being a predetermined function of actual cantilever deflection, wherein the moving step comprises transmitting a lateral compensation signal to an actuator of the instrument that is pre-calibrated prior to the moving step to determine the relationship between actual cantilever deflection and lateral motion. ### Claim 32 (depends on 31) The method as recited in claim 31, wherein the cantilever is a passive cantilever including a base and a free end portion that bears the tip, and wherein the moving step comprises moving the probe as a whole relative to the sample and is performed directly as a function of monitored cantilever deflection, and wherein the monitoring step comprises measuring cantilever deflection. ### Claim 33 (depends on 31) The method as recited in claim 31, wherein the probe is an active probe which has an active cantilever including a base, a free end portion that bears the tip, and an actuator that is selectively energizable to bend the cantilever, and wherein the monitoring step comprises monitoring a drive signal supplied to the active cantilever.