JP5930153B2 - Scanning probe microscope and control method thereof - Google Patents

Description

  The present invention relates to a scanning probe microscope.

  A scanning probe microscope (SPM) is a general term for a scanning microscope that acquires information on the surface of a sample while scanning a mechanical probe and displays the mapping. The SPM includes a scanning tunneling microscope (STM), an atomic force microscope (AFM), a scanning magnetic force microscope (MFM), a scanning near-field light microscope (SNOM), and the like.

  AFM is the most widely used SPM, and cantilever with a mechanical probe at its free end, optical displacement sensor that detects the displacement of the cantilever, and relative scanning of the mechanical probe and the sample. A scanning mechanism is provided as a main element. Since the optical displacement sensor has a simple configuration and high detection sensitivity, an optical lever type optical displacement sensor is most widely used. This optical lever type optical displacement sensor irradiates a light beam with a diameter of several μm to several tens of μm on the cantilever, and changes the reflection direction of the reflected light according to the change of the cantilever warp by using a two-part optical detector or the like By capturing it, an electrical signal reflecting the operation of the mechanical probe at the free end of the cantilever is output. In the AFM, the relative position between the mechanical probe and the sample is set to XY while the relative distance between the mechanical probe and the sample is controlled in the Z direction so that the output of the optical displacement sensor becomes constant by the scanning mechanism. By scanning in the direction, the uneven state of the sample surface is mapped and displayed on a computer monitor.

  AFM often employs a method (AC mode) in which a cantilever is vibrated and an interaction between a sample and a probe is detected from its vibration characteristics. This is because there is an advantage that the force acting between the sample and the probe can be kept weak compared to the normal method (called contact mode). In this AC mode AFM, the vibration of the cantilever caused by the interaction between the sample and the probe, that is, one of amplitude change or phase change of the displacement is detected, and the surface shape of the sample is measured based on the detection result. .

  Japanese Patent Application Laid-Open No. 2008-232984 discloses one such AC mode AFM. The AC mode AFM is configured to detect by switching one of the amplitude change and the phase change.

JP 2008-232984 A

  In the AC mode AFM, the interaction between the sample and the probe often detects a change in vibration state (amplitude change or phase change) in a repulsive region, and an image is formed based on the change. The amplitude of the cantilever displacement decreases as the repulsive force between the sample and the probe increases. The phase of the cantilever displacement advances as the repulsion increases. The change in amplitude has a large change rate in a hard sample and a small change rate in a soft sample. That is, the amplitude change detection sensitivity is high for a hard sample and low for a soft sample. On the other hand, the change in phase is small for a hard sample and high for a soft sample. That is, the phase change detection sensitivity is low for a hard sample and high for a soft sample. Conventional AC mode AFM detects repulsive force based on either amplitude change or phase change, so for samples containing both hard and soft parts, both hard and soft parts It is difficult to detect repulsive force with high sensitivity. This not only reduces the measurement accuracy, but also makes the control unstable.

  The present invention has been made in view of such a current situation, and an object of the present invention is to provide a scanning probe that can stably measure the surface shape of a sample in which a hard part and a soft part are mixed with high accuracy. To provide a microscope.

A scanning probe microscope according to the present invention includes a cantilever having a probe at a free end, a scanning unit that relatively moves the probe and the sample three-dimensionally, and an addition that vibrates the cantilever based on an excitation signal. A vibration unit; a displacement detection unit that detects displacement of the cantilever and outputs a displacement signal representing the displacement; an amplitude information detection unit that generates an amplitude signal including amplitude information of the displacement signal; and the excitation signal And a phase difference information detection unit that generates a phase signal including phase difference information of the displacement signal, an arithmetic unit that generates a hybrid signal by adding the amplitude signal and the phase signal, and controls the scanning unit A control unit is provided. The control unit controls the distance between the probe and the sample based on both the amplitude signal and the phase signal included in the hybrid signal .

  ADVANTAGE OF THE INVENTION According to this invention, the scanning probe microscope which can measure the surface shape stably highly accurately also with respect to the sample in which a hard part and a soft part are mixed is provided.

The structure of the scanning probe microscope of 1st embodiment is shown. The structure of the hybrid signal calculation part in 1st embodiment is shown. -Shows the relationship between Asin φ and φ. The structure of the hybrid signal calculation part in 2nd embodiment is shown. The relationship between Acos φ and φ and the relationship between −Asin φ and φ are shown.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

<First embodiment>
The configuration of the scanning probe microscope of the present embodiment is shown in FIG. As shown in FIG. 1, the scanning probe microscope has a cantilever 12 having a probe 11 at a free end. The cantilever 12 can be held by the holder 13 so as to face the sample 19.

  The scanning probe microscope also has a displacement detector 15 that detects the displacement of the cantilever 12 and outputs a displacement signal representing the displacement. The displacement detection unit 15 includes an optical lever type optical displacement sensor, and receives a laser light source 16 that irradiates a laser beam focused on the back surface of the cantilever 12 and a laser beam reflected from the back surface of the cantilever 12. The division detector 17 and an operational amplifier 18 that generates a displacement signal of the cantilever 12 from the output of the division detector 17 are configured.

  The scanning probe microscope also includes a vibration unit 14 that vibrates the cantilever 12 based on the vibration signal, and a hybrid signal calculation unit 30 that supplies the vibration signal to the vibration unit 14. The vibration part 14 is provided in the holder 13, for example. The vibration unit 14 is made of, for example, a piezoelectric element, and can vibrate the cantilever 12 with a predetermined amplitude at a frequency near its mechanical resonance frequency. The hybrid signal calculation unit 30 can generate a hybrid signal from the displacement signal output from the displacement detection unit 15 in addition to outputting the excitation signal. Details of the hybrid signal will be described later.

  The scanning probe microscope also includes a scanning unit 20 that relatively moves the sample 19 and the probe 11 in three dimensions. The scanning unit 20 includes a Z scanner 21 and an XY scanner 22. The Z scanner 21 is disposed on the XY scanner 22, and the sample 19 can be placed on the Z scanner 21 via a sample table (not shown). The Z scanner 21 is driven by a Z driver 23 and can move the sample 19 in the Z direction with respect to the probe 11. The XY scanner 22 is driven by an XY driver 24 and can move the sample 19 in the XY direction with respect to the probe 11.

  The scanning probe microscope also includes a controller 25 that controls the Z driver 23 and the XY driver 24, and a host computer 27 that forms an image of the surface of the sample 19. The controller 25 can generate an XY scanning signal for two-dimensionally scanning the probe 11 along the surface of the sample 19 and a Z control signal for controlling the distance between the probe 11 and the sample 19. . The controller 25 has a Z control unit 26 that generates a Z control signal from the hybrid signal. The host computer 27 can form an image of the surface of the sample 19 using the XY scanning signal and the Z control signal generated by the controller 25.

  The configuration of the hybrid signal calculation unit 30 is shown in FIG. As shown in FIG. 2, the hybrid signal calculation unit 30 includes a signal generator 34, an amplitude information detection unit 31, a phase difference information detection unit 32, and an addition processing unit 35.

  The signal generator 34 generates an excitation signal that causes the cantilever 12 to vibrate with a predetermined amplitude at a frequency near its mechanical resonance frequency, and outputs this to the excitation unit 14. The signal generator 34 also outputs a synchronization signal synchronized with the excitation signal to the phase difference information detection unit 32. This synchronization signal can be composed of, for example, a square wave signal (logic signal) having the same frequency and the same phase as the excitation signal.

  The amplitude information detection unit 31 generates and outputs an amplitude signal including information on the amplitude of the displacement signal of the cantilever 12 supplied from the displacement detection unit 15.

  The phase difference information detection unit 32 generates and outputs a phase signal including information on the phase difference between the displacement signal of the cantilever 12 supplied from the displacement detection unit 15 and the synchronization signal supplied from the signal generator 34. Since the synchronization signal and the excitation signal have the same frequency and phase, the phase difference between the displacement signal and the synchronization signal is equivalent to the phase difference between the displacement signal and the excitation signal.

  The phase difference information detection unit 32 includes a phase adjustment unit 33 that can adjust the phase of the synchronization signal supplied from the signal generator 34. The phase adjustment unit 33 can give a desired phase offset to the phase of the synchronization signal supplied from the signal generator 34. Therefore, the phase adjustment unit 33 can give a desired phase offset to the phase difference between the displacement signal and the synchronization signal. The phase difference information detection unit 32 generates and outputs a phase signal including information on the phase difference between the synchronization signal given the phase offset and the displacement signal. The phase difference between the synchronization signal to which the phase offset is given and the displacement signal is equivalent to the phase difference given to the phase difference between the displacement signal and the synchronization signal.

  The addition processing unit 35 adds the amplitude signal supplied from the amplitude information detection unit 31 and the phase signal supplied from the phase difference information detection unit 32, and outputs this as a hybrid signal. Here, the amplitude signal and the phase signal may be negative signals. That is, the addition process includes a subtraction process in a narrow sense.

  Here, the signal processing of the hybrid signal calculation unit 30 will be described in detail.

Let the vibration signal be A ₀ sin ω ₀ t. Here, A ₀ is the amplitude of the vibration signal, ω ₀ is the angular frequency of the vibration signal, and t is time. ω ₀ has a value approximately equal to 2π · f _{0 where} the resonance frequency of the cantilever 12 is f ₀ .

The synchronization signal is, for example, a square wave signal having the same frequency (that is, angular frequency ω ₀ ) and the same phase as the excitation signal.

The displacement signal of the cantilever 12 is set as Asin (ω ₀ t + φ ₀ + φ). Here, A is the amplitude of the displacement signal, φ ₀ is the initial phase difference of the displacement signal that exists when the probe 11 and the sample 19 are not in contact, and φ is that the probe 11 and the sample 19 are in contact with each other. The phase difference of the displacement signal generated due to the above. Hereinafter, this phase difference is referred to as a phase shift amount for convenience. When the probe 11 and the sample 19 are not in contact, φ is zero. A and φ are detection targets.

The phase adjustment unit 33 gives a phase offset ψ to the phase of the synchronization signal output from the signal generator 34. That is, the phase adjustment unit 33 shifts the phase of the synchronization signal by ψ. This is equivalent to giving a phase offset −ψ to the phase difference between the displacement signal of the cantilever 12 and the synchronization signal (that is, the excitation signal). The phase difference information detection unit 32 receives a phase signal Acos (φ ₀ + φ−ψ) including information on the phase difference between the displacement signal Asin (ω ₀ t + φ ₀ + φ) of the cantilever 12 and the synchronization signal given the phase offset ψ. Generate and output.

Preferably, the phase adjustment unit 33 shifts the phase of the synchronization signal by φ ₀ −π / 2. That is, ψ = φ ₀ −π / 2. In this case, the phase signal output from the phase difference information detection unit 32 is Acos {φ ₀ + φ− (φ ₀ −π / 2)} = − A sin φ.

  FIG. 3 is a graph showing the relationship between -Asin φ and φ. As can be seen from this graph, -Asin φ is most sensitive (high sensitivity) to the change in the phase shift amount φ when φ = 0.

When the measurement part is hard, the amplitude of the displacement signal of the cantilever 12 changes more greatly than the phase. This amplitude decreases as the repulsive force acting between the sample 19 and the probe 11 increases. On the other hand, when the measurement portion is soft, the displacement signal of the cantilever 12 changes in phase more greatly than the amplitude. This phase advances as the repulsive force acting between the sample 19 and the probe 11 increases (shifts in the + φ direction). For this reason, it is preferable that the phase signal output from the phase difference information detection unit 32 changes sensitively near φ = 0 and decreases as φ advances in accordance with the change in amplitude. For this reason, the phase offset ψ is preferably set to ψ = φ ₀ −π / 2 so that the phase signal Acos (φ ₀ + φ−ψ) becomes −Asinφ.

As can be seen again with reference to FIG. 2, the amplitude information detector 31 detects the amplitude A of the displacement signal Asin (ω ₀ t + φ ₀ + φ) of the cantilever 12 and outputs an amplitude signal A representing the amplitude.

  The addition processing unit 35 adds the amplitude signal (A) and the phase signal (-Asinφ) to obtain A-Asinφ, and outputs this as a hybrid signal.

  The hybrid signal output from the addition processing unit 35 is supplied to the Z control unit 26 in the controller 25 as shown in FIG. The Z control unit 26 generates a Z control signal for controlling the distance between the sample 19 and the probe 11 so as to keep the hybrid signal constant, and supplies this to the Z driver 23. The Z driver 23 controls the Z scanner 21 according to the supplied Z control signal. As a result, the distance between the sample 19 and the probe 11 is controlled so as to keep the hybrid signal constant.

  The controller 25 generates an XY scanning signal for two-dimensionally scanning the probe 11 along the surface of the sample 19 and supplies it to the XY driver 24. The XY driver 24 controls the XY scanner 22 in accordance with the supplied XY scanning signal. As a result, the probe 11 scans two-dimensionally along the surface of the sample 19.

  The controller 25 also supplies an XY scanning signal and a Z control signal to the host computer 27. The host computer 27 forms an image of the surface of the sample 19 using the XY scanning signal and the Z control signal, displays the image, and stores the image data.

  In the scanning probe microscope of the present embodiment, the repulsive force acting between the sample 19 and the probe 11 is detected as a hybrid signal A-Asinφ, and the distance between the sample 19 and the probe 11 is controlled based on the detected signal. When the measurement part is hard, the amplitude signal A changes greatly, and when the measurement part is soft, the phase signal -Asinφ changes greatly. For this reason, even if a hard part and a soft part are mixed in the sample 19, repulsive force acting between the sample 19 and the probe 11 can be detected with high sensitivity. As a result, it is possible to stably measure the surface shape of a sample in which a hard portion and a soft portion are mixed with high accuracy.

<Second embodiment>
The scanning probe microscope of the present embodiment is the same as the scanning probe microscope of the first embodiment except that the configuration of the hybrid signal calculation unit is different. Therefore, here, description will be given with emphasis on the configuration and operation of the hybrid signal calculation unit of the present embodiment.

  FIG. 4 shows the configuration of the hybrid signal calculation unit 40 of this embodiment. As shown in FIG. 4, the hybrid signal calculation unit 40 includes a signal generator 45, an amplitude information detection unit 41, a phase difference information detection unit 43, and an addition processing unit 46.

  The signal generator 45 generates an excitation signal that vibrates the cantilever 12 with a predetermined amplitude at a frequency near its mechanical resonance frequency, and outputs this to the excitation unit 14. The signal generator 45 also outputs a synchronization signal synchronized with the excitation signal to the amplitude information detection unit 41 and the phase difference information detection unit 43. This synchronization signal can be composed of, for example, a square wave signal (logic signal) having the same frequency and the same phase as the excitation signal.

  The amplitude information detection unit 41 generates and outputs an amplitude signal including information on the amplitude of the displacement signal of the displacement signal of the cantilever 12 supplied from the displacement detection unit 15.

  The amplitude information detection unit 41 includes a phase adjustment unit 42 that can adjust the phase of the synchronization signal supplied from the signal generator 45. The phase adjustment unit 42 can give a desired phase offset to the phase of the synchronization signal supplied from the signal generator 45. Therefore, the phase adjustment unit 42 can give a desired phase offset to the phase difference between the displacement signal and the synchronization signal. The amplitude information detection unit 41 outputs, as amplitude information, a first phase difference signal including information on the phase difference between the synchronization signal given the phase offset and the displacement signal.

  The phase difference information detector 43 generates and outputs a phase signal including information on the phase difference between the displacement signal of the cantilever 12 supplied from the displacement detector 15 and the synchronization signal supplied from the signal generator 45.

  The phase difference information detection unit 43 includes a phase adjustment unit 44 that can adjust the phase of the synchronization signal supplied from the signal generator 45. The phase adjustment unit 44 can give a desired phase offset to the phase of the synchronization signal supplied from the signal generator 45. Therefore, the phase adjustment unit 44 can give a desired phase offset to the phase difference between the displacement signal and the synchronization signal. The phase difference information detection unit 43 outputs a second phase difference signal including information on the phase difference between the synchronization signal given the phase offset and the displacement signal as the phase signal.

  Here, since the frequency and the phase of the synchronization signal and the excitation signal are the same, the phase difference between the displacement signal and the synchronization signal is equivalent to the phase difference between the displacement signal and the excitation signal. Further, the phase difference between the synchronization signal to which the phase offset is given and the displacement signal is equivalent to the phase difference given to the phase difference between the displacement signal and the synchronization signal.

  The addition processing unit 46 adds the amplitude signal supplied from the amplitude information detection unit 41, that is, the first phase difference signal, and the phase signal supplied from the phase difference information detection unit 43, that is, the second phase difference signal. Output as a hybrid signal.

  Here, the signal processing of the hybrid signal calculation unit 40 will be described in detail.

Let the vibration signal be A ₀ sin ω ₀ t. Here, A ₀ is the amplitude of the vibration signal, ω ₀ is the angular frequency of the vibration signal, and t is time. ω ₀ has a value approximately equal to 2π · f _{0 where} the resonance frequency of the cantilever 12 is f ₀ .

The synchronization signal is, for example, a square wave signal having the same frequency (that is, angular frequency ω ₀ ) and the same phase as the excitation signal.

The displacement signal of the cantilever 12 is set as Asin (ω ₀ t + φ ₀ + φ). Here, A is the amplitude of the displacement signal, φ ₀ is the initial value of the phase of the displacement signal when the probe 11 and the sample 19 are not in contact, and φ is that the probe 11 and the sample 19 are in contact with each other. This is the phase shift amount of the displacement signal generated due to this. When the probe 11 and the sample 19 are not in contact, φ is zero. A and φ are detection targets.

The phase adjustment unit 42 gives a phase offset ψ ₁ to the phase of the synchronization signal output from the signal generator 45. That is, the phase adjustment unit 42 shifts the phase of the synchronization signal by ψ ₁ . The amplitude information detection unit 41 includes, as an amplitude signal, a first phase difference signal Acos including information on a phase difference between the displacement signal Asin (ω ₀ t + φ ₀ + φ) of the cantilever 12 and the synchronization signal to which the phase offset ψ ₁ is given. (Φ ₀ + φ−ψ ₁ ) is generated and output.

Preferably, the phase adjusting unit 42 is shifted by phi ₀ the phase of the synchronization signal. That is, ψ ₁ = φ ₀ . In this case, the amplitude signal output from the amplitude information detection unit 41 is A cos (φ ₀ + φ−φ ₀ ) = A cos φ.

The phase adjustment unit 44 gives a phase offset ψ ₂ to the phase of the synchronization signal output from the signal generator 45. That is, the phase adjustment unit 44 shifts the phase of the synchronization signal by ψ ₂ . The phase difference information detection unit 43 includes, as a phase signal, a second phase difference signal including information on the phase difference between the displacement signal Asin (ω ₀ t + φ ₀ + φ) of the cantilever 12 and the synchronization signal to which the phase offset ψ ₂ is given. Acos (φ ₀ + φ−ψ ₂ ) is generated and output.

Preferably, the phase adjustment unit 44 shifts the phase of the synchronization signal by φ ₀ −π / 2. That is, ψ ₂ = φ ₀ -π / 2. In this case, the phase signal output from the phase difference information detection unit 43 is Acos {φ ₀ + φ− (φ ₀ −π / 2)} = − A sin φ.

  FIG. 5A is a graph showing the relationship between A cos φ and φ. As can be seen from this graph, A cos φ is the least insensitive (low sensitivity) to the change in the phase shift amount φ when φ = 0.

  FIG. 5B is a graph showing the relationship between -Asin φ and φ. As can be seen from this graph, −A sin φ is most sensitive (high sensitivity) to a change in the phase shift amount φ when φ = 0, and decreases as the phase advances from zero. That is, the phase signal −Asinφ decreases as the repulsive force acting between the sample 19 and the probe 11 increases, similarly to the direction of change of the amplitude signal.

Then, as shown in FIG. 4, the addition processing unit 46 adds the amplitude signal, that is, the first phase difference signal Acosφ, and the phase signal, that is, the second phase difference signal -Asinφ, to obtain Acosφ-Asinφ, which is obtained as a hybrid signal Output as.
By doing this, when the measurement object is hard, that is, when the amplitude change is larger than the phase shift amount φ, the signal change amount is
Acosφ> -Asinφ
Thus, the signal of Acosφ works dominantly. Further, when the change of φ is small, cos φ≈1 can be set, so that Acos φ≈A, that is, Acos φ can be regarded as substantially the same as A.
Further, when the measurement object is soft, that is, when the phase shift amount φ is larger than the amplitude change, the signal change amount is
-Asinφ> Acosφ
Thus, the signal −Asinφ works dominantly. At this time, since the change in φ is large, the change in Acos φ is also larger than in the first embodiment (in the case of only A).

  The hybrid signal output from the addition processing unit 46 is supplied to the Z control unit 26 in the controller 25 as shown in FIG. The Z control unit 26 generates a Z control signal for controlling the distance between the sample 19 and the probe 11 so as to keep the hybrid signal constant, and supplies this to the Z driver 23. The Z driver 23 controls the Z scanner 21 according to the supplied Z control signal. As a result, the distance between the sample 19 and the probe 11 is controlled so as to keep the hybrid signal constant.

  The controller 25 generates an XY scanning signal for two-dimensionally scanning the probe 11 along the surface of the sample 19 and supplies it to the XY driver 24. The XY driver 24 controls the XY scanner 22 in accordance with the supplied XY scanning signal. As a result, the probe 11 scans two-dimensionally along the surface of the sample 19.

  The controller 25 also supplies an XY scanning signal and a Z control signal to the host computer 27. The host computer 27 forms an image of the surface of the sample 19 using the XY scanning signal and the Z control signal, displays the image, and stores the image data.

  In the scanning probe microscope of the present embodiment, the repulsive force acting between the sample 19 and the probe 11 is detected as a hybrid signal Acosφ-Asinφ, and the distance between the sample 19 and the probe 11 is controlled based on the detected signal. When the measurement part is hard, Acos φ can be regarded as almost A, and thus Acos φ changes greatly. As a result, the repulsive force acting between the sample 19 and the probe 11 can be detected for the hard portion with the same sensitivity as the first embodiment. When the measurement part is soft, -Asinφ changes greatly and Acosφ also changes. As a result, for the soft part, the repulsive force acting between the sample 19 and the probe 11 can be detected with higher sensitivity than in the first embodiment. As a result, it is possible to stably measure the surface shape of a sample in which a hard portion and a soft portion are mixed with high accuracy.

  The embodiments of the present invention have been described above with reference to the drawings. However, the present invention is not limited to these embodiments, and various modifications and changes can be made without departing from the scope of the present invention. Also good. Various modifications and changes described here may include implementations in which the above-described embodiments are appropriately combined.

DESCRIPTION OF SYMBOLS 11 ... Probe, 12 ... Cantilever, 13 ... Holder, 14 ... Excitation part, 15 ... Displacement detection part, 16 ... Laser light source, 17 ... Divided detector, 18 ... Operation amplifier, 19 ... Sample, 20 ... Scanning part, 21 ... Z scanner, 22 ... XY scanner, 23 ... Z driver, 24 ... XY driver, 25 ... Controller, 26 ... Z control unit, 27 ... Host computer, 30 ... Hybrid signal calculation unit, 31 ... Amplitude information detection unit, 32 ... Phase difference information detection unit, 33 ... Phase adjustment unit, 34 ... Signal generator, 35 ... Addition processing unit, 40 ... Hybrid signal calculation unit, 41 ... Phase difference information detection unit, 42 ... Phase adjustment unit, 43 ... Phase difference information Detection unit, 44... Phase adjustment unit, 45... Signal generator, 46.

Claims (9)

A cantilever with a probe at the free end,
A scanning unit that relatively moves the probe and the sample three-dimensionally;
An excitation unit that vibrates the cantilever based on an excitation signal;
A displacement detector that detects the displacement of the cantilever and outputs a displacement signal representing the displacement;
An amplitude information detector that generates an amplitude signal including information on the amplitude of the displacement signal;
A phase difference information detection unit that generates a phase signal including information on a phase difference between the excitation signal and the displacement signal;
An arithmetic unit that generates a hybrid signal by adding the amplitude signal and the phase signal ;
A control unit for controlling the scanning unit;
The control unit is a scanning probe microscope that controls a distance between the probe and the sample based on both the amplitude signal and the phase signal included in the hybrid signal. The scanning probe microscope according to claim 1, wherein the control unit controls a distance between the probe and the sample so as to keep the hybrid signal constant. The phase difference information detection unit includes a phase adjustment unit that gives a phase offset to a phase difference between the excitation signal and the displacement signal,
Wherein the excitation signal _{A 0 sinω} 0 t, the displacement signal when placed and _{Asin (ω 0 t + φ 0} + φ) ( where, _{A 0} is the excitation signal amplitude, omega ₀ is the excitation signal Angular frequency, t is time, A is the amplitude of the displacement signal, φ ₀ is the initial phase difference of the displacement signal that exists when the probe and the sample are not in contact, and φ is the probe And the phase shift amount of the displacement signal generated due to the contact of the sample) and the phase offset as ψ,
The amplitude information detection unit generates A,
The phase difference information detection unit generates A cos (φ ₀ + φ−ψ),
The arithmetic _{unit, A + Acos (φ 0 +} φ-ψ) to produce a scanning probe microscope according to claim 1 or 2. Wherein the phase offset [psi, a _{ψ = π / 2-φ 0} , therefore, the phase difference information detection unit generates a -Asinfai, the arithmetic unit generates an A-Asinφ, claim 3 Scanning probe microscope. The amplitude information detection unit includes a first phase adjustment unit that gives a first phase offset to a phase difference between the excitation signal and the displacement signal,
The phase difference information detection unit includes a second phase adjustment unit that gives a second phase offset to the phase difference between the excitation signal and the displacement signal,
Wherein the excitation signal _{A 0 sinω} 0 t, the displacement signal when placed and _{Asin (ω 0 t + φ 0} + φ) ( where, _{A 0} is the excitation signal amplitude, omega ₀ is the excitation signal Angular frequency, t is time, A is the amplitude of the displacement signal, φ ₀ is the initial phase difference of the displacement signal that exists when the probe and the sample are not in contact, and φ is the probe And the phase shift amount of the displacement signal generated due to contact of the sample), the first phase offset is ψ ₁ , the second phase offset is ψ ₂ ,
The amplitude information detection unit generates A cos (φ ₀ + φ−ψ ₁ ),
The phase difference information detection unit generates A cos (φ ₀ + φ−ψ ₂ ),
The arithmetic _{unit, Acos (φ 0 + φ-} ψ 1) + Acos (φ 0 + φ-ψ 2) for generating a scanning probe microscope according to claim 1 or 2. The first phase offset ψ ₁ is ψ ₁ = φ ₀ , and the second phase offset ψ ₂ is ψ ₂ = π / 2−φ _0. Therefore, the amplitude information detection unit is configured as Acos φ. The scanning probe microscope according to claim 5 , wherein the phase difference information detection unit generates -Asinφ, and the calculation unit generates Acosφ-Asinφ. Oscillating a cantilever having a probe at a free end based on an excitation signal;
Scanning the probe along the surface of the sample;
Detecting the displacement of the cantilever and outputting a displacement signal representing the displacement;
Generating an amplitude signal including amplitude information of the displacement signal;
Generating a phase signal including information on a phase difference between the excitation signal and the displacement signal;
Generating a composite signal by adding processing the phase signal and the amplitude signal,
A method for controlling a scanning probe microscope, comprising: a step of controlling a distance between the probe and the sample based on both the amplitude signal and the phase signal included in the hybrid signal. 8. The control method according to claim 7, wherein the step of controlling the distance between the probe and the sample controls the distance between the probe and the sample so as to keep the hybrid signal constant. The amplitude signal is a first phase difference signal including information on a phase difference between the excitation signal and the displacement signal,
The control method according to claim 7 or 8 , wherein the phase signal is a second phase difference signal including information on a phase difference between the excitation signal and the displacement signal.

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