# US 11,029,329 B2 · Method of and system for detecting structures on or below the surface of a sample using a probe including a cantilever and a probe tip > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,029,329 B2 - Document ID: US11029329B2 - Status: Granted - Kind: B2 - Application number: 16/477,845 - Filed: 2018-01-12 - Published: 2019-12-05 - Granted: 2021-06-08 - Earliest claimed: 2017-01-13 - Assignees: Nederlandse Organisatie voor toegepast-natuurwetenschappelijk onderzoek TNO - Applicants: Nederlandse Organisatie voor toegepast-natuurwetenschappelijk onderzoek TNO - Inventors: Hamed Sadeghian Marnani - Web page: https://patentgrep.com/patent/US11029329B2 ## CPC - G01Q 60/30: Scanning potential microscopy - G01N 29/022: {Fluid sensors based on microsensors, e.g. quartz crystal-microbalance [QCM], surface acoustic wave [SAW] devices, tuning forks, cantilevers, flexural plate wave [FPW] devices (microdevices per se B81B)} - G01N 29/0681: {by acoustic microscopy, e.g. scanning acoustic microscopy} - G01N 29/2418: {using optoacoustic interaction with the material, e.g. laser radiation, photoacoustics (photoacoustic cells G01N21/1702; measuring characteristics of vibrations by using radiation-sensitive means G01H9/00; acousto-optical conversion techniques for short-range imaging G01S15/8965; sound-producing devices using laser bundle G10K15/046)} - G01N 29/265: by moving the sensor relative to a stationary material - G01Q 60/32: AC mode - G01Q 60/38: Probes, their manufacture, or their related instrumentation, e.g. holders - G01N 2291/0427: Flexural waves, plate waves, e.g. Lamb waves, tuning fork, cantilever - G01Q: SCANNING-PROBE TECHNIQUES OR APPARATUS; APPLICATIONS OF SCANNING-PROBE TECHNIQUES, e.g. SCANNING PROBE MICROSCOPY [SPM] - G01N: INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES (measuring or testing apparatus or processes other than immunoassay, involving enzymes or microorganisms C12M, C12Q) ## Abstract The present document relates to a method of detecting structures on or below the surface of a sample using a probe including a cantilever and a probe tip, the cantilever being characterized by one ore more normal modes of resonance including a fundamental resonance frequency, the method including: applying, using a transducer, a vibrational input signal to the sample; sensing, while the probe tip is in contact with the surface, an output signal indicative of motion of the probe tip due to vibrations at the surface induced by the vibrational input signal; wherein the vibrational input signal comprises at least a first signal component having a frequency within a range of 10 to 100 megahertz; and wherein the vibrational input signal is amplitude modulated using at least a second signal component having a modulation frequency below 5 megahertz. The present document further relates to a scanning probe microscopy method. ## Claims ### Claim 1 A method of detecting structures of nanometer size semiconductor elements on or below the surface of a sample using a probe that comprises a cantilever and a probe tip, wherein the cantilever is characterized by one or more normal modes of resonance including a fundamental resonance frequency, wherein the method comprises: applying, using a transducer, a vibrational input signal exclusively from a location of the transducer; and sensing, while the probe tip is in contact with the surface of the sample, an output signal indicative of motion of the probe tip due to vibrations at the surface induced by the vibrational input signal, wherein the vibrational input signal comprises a first signal component having a frequency within a range of 10 megahertz to 10 gigahertz, and wherein the vibrational input signal is amplitude modulated using a second signal component having a modulation frequency below 5 megahertz. ### Claim 2 (depends on 1) The method according to claim 1, wherein the second signal component has a modulation frequency within a range of 20% from at least one of the normal modes of resonance of the cantilever. ### Claim 3 (depends on 2) The method according to claim 2, wherein the modulation frequency is a times the fundamental frequency, wherein a is within a range of 0.8 to 1.2. ### Claim 4 (depends on 1) The method according to claim 1, wherein the sensing the output signal comprises a step of measuring signal characteristics of the output signal at or near a measurement frequency. ### Claim 5 (depends on 4) The method according to claim 4, wherein the measurement frequency is taken from the group consisting of: within a range of 20% from at least one of the normal modes of resonance of the cantilever; b times the fundamental frequency of cantilever resonance, wherein b is within a range of 0.8 to 1.2; and equal to or within 5% from the modulation frequency. ### Claim 6 (depends on 1) The method according to claim 1, wherein the sensing the output signal comprises measuring signal characteristics of the output signal, wherein the signal characteristics includes at least one of the group consisting of: a phase, and an amplitude of the output signal. ### Claim 7 (depends on 1) The method according to claim 1, wherein the sample includes at least one of the group consisting of: a semiconductor structure embedded within the sample; a multilayer semiconductor structure or element; and a three dimensional semiconductor structure, wherein the structure is comprising structural features having at least one size dimension smaller than 10 nanometers. ### Claim 8 A scanning probe microscopy system for detecting structures of nanometer size semiconductor elements on or below the surface of a sample, comprising: a probe for scanning the sample surface, wherein the probe comprises a probe tip mounted on a cantilever, wherein the cantilever is characterized by one or more normal modes of resonance including a fundamental resonance frequency, and wherein the probe is mounted on a sensing head arranged for bringing the probe tip in contact with the sampling surface; a transducer for applying a vibrational input signal exclusively from a location of the transducer; and a probe deflection sensor for producing an output signal indicative of motion of the probe tip due to vibrations at the surface induced by the vibrational input signal, wherein the transducer is configured for producing the vibrational input signal so as to comprise a first signal component having a frequency within a range of 10 megahertz to 10 gigahertz, and wherein the transducer is configured for amplitude modulating the vibrational input signal using a second signal component having a modulation frequency below 5 megahertz. ### Claim 9 (depends on 8) The scanning probe microscopy system according to claim 8, wherein the transducer, being configured for amplitude modulating the vibrational input signal using the second signal component, is configured for providing the second signal component with the modulation frequency being within a range of 20% from at least one of the normal modes of resonance of the cantilever. ### Claim 10 (depends on 9) The scanning probe microscopy system according to claim 9, wherein the transducer, being configured for amplitude modulating the vibrational input signal using the second signal component, is configured for providing the second signal component having with the modulation frequency being a times the fundamental frequency, wherein a is within a range of 0.8 to 1.2. ### Claim 11 (depends on 8) The scanning probe microscopy system according to claim 8, further comprising a controller or analyzer system in communicative connection with the probe deflection sensor, wherein the controller or analyzer system is configured for determining a signal characteristics of the output signal at or near a measurement frequency. ### Claim 12 (depends on 11) The scanning probe microscopy system according to claim 11, wherein the controller or analyzer system is configured for performing said determining of the signal characteristics of the output signal at the measurement frequency, wherein the measurement frequency is taken from the group consisting of: within a range of 20% from at least one of the normal modes of resonance of the cantilever; b times the fundamental frequency of cantilever resonance, wherein b is within a range of 0.8 to 1.2, preferably wherein b is within a range of 0.95 to 1.05, more preferably wherein b is 1.00; and equal to or within 5% from the modulation frequency. ### Claim 13 (depends on 8) The scanning probe microscopy system according to claim 8, further comprising a controller or analyzer system in communicative connection with the probe deflection sensor, wherein the controller or analyzer system is configured for determining signal characteristics of the output signal at or near a measurement frequency, and wherein said signal characteristics includes at least one of the group consisting of: a phase, and an amplitude of the output signal. ### Claim 14 (depends on 9) The scanning probe microscopy system according to claim 9, wherein the transducer, being configured for amplitude modulating the vibrational input signal using the second signal component, is configured for providing the second signal component having with the modulation frequency being a times the fundamental frequency, wherein a is within a range of 0.95 to 1.05. ### Claim 15 (depends on 9) The scanning probe microscopy system according to claim 9, wherein the transducer, being configured for amplitude modulating the vibrational input signal using the second signal component, is configured for providing the second signal component having with the modulation frequency being a times the fundamental frequency, wherein a is 1.00. ### Claim 16 (depends on 2) The method according to claim 2, wherein the modulation frequency is a times the fundamental frequency, wherein a is within a range of 0.95 to 1.05. ### Claim 17 (depends on 2) The method according to claim 2, wherein the modulation frequency is a times the fundamental frequency, wherein a is 1.00. ### Claim 18 (depends on 1) The method according to claim 1, wherein the vibrational input signal is applied to the sample during the applying. ### Claim 19 (depends on 1) The method according to claim 1, wherein the vibrational input signal is applied to the probe during the applying. ### Claim 20 (depends on 8) The system of claim 8, wherein the vibrational input signal is applied to the sample. ### Claim 21 (depends on 8) The system of claim 8, wherein the vibrational input signal is applied to the probe.